Monoterpene phenolic compound thymol promotes browning of 3T3-L1 adipocytes.

PubMed

Choi, Jae Heon; Kim, Sang Woo; Yu, Rina; Yun, Jong Won

2017-10-01

Appearance of brown-like adipocytes within white adipose tissue depots (browning) is associated with improved metabolic phenotypes, and thus a wide variety of dietary agents that contribute to browning of white adipocytes are being studied. The aim of this study was to assess the browning effect of thymol, a dietary monoterpene phenolic compound, in 3T3-L1 white adipocytes. Thymol-induced fat browning was investigated by determining expression levels of brown fat-specific genes and proteins by real-time RT-PCR and immunoblot analysis, respectively. Moreover, the molecular mechanism underlying the fat-browning effect of thymol was investigated by determining expression levels of key players responsible for browning in the presence of kinase inhibitors. Thymol promoted mitochondrial biogenesis and enhanced expression of a core set of brown fat-specific markers as well as increased protein levels of PPARγ, PPARδ, pAMPK, pACC, HSL, PLIN, CPT1, ACO, PGC-1α, and UCP1, suggesting its possible role in browning of white adipocytes, augmentation of lipolysis, fat oxidation, and thermogenesis, and reduction of lipogenesis. Increased expression of UCP1 and other brown fat-specific markers by thymol was tightly coordinated with activation of β3-AR as well as AMPK, PKA, and p38 MAPK. Our findings suggest that 3T3-L1 is a potential cell model for screening browning agents. Thymol plays multiple modulatory roles in the form of inducing the brown-like phenotype as well as enhancing lipid metabolism. Thus, thymol may be explored as a potentially promising food additive for prevention of obesity.

40 CFR 180.1240 - Thymol; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Thymol; exemption from the requirement of a tolerance. 180.1240 Section 180.1240 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1240 Thymol;...

Thymol inhibits Staphylococcus aureus internalization into bovine mammary epithelial cells by inhibiting NF-κB activation.

PubMed

Wei, Zhengkai; Zhou, Ershun; Guo, Changming; Fu, Yunhe; Yu, Yuqiang; Li, Yimeng; Yao, Minjun; Zhang, Naisheng; Yang, Zhengtao

2014-01-01

Bovine mastitis is one of the most costly and prevalent diseases in the dairy industry and is characterised by inflammatory and infectious processes. Staphylococcus aureus (S. aureus), a Gram-positive organism, is a frequent cause of subclinical, chronic mastitis. Thymol, a monocyclic monoterpene compound isolated from Thymus vulgaris, has been reported to have antibacterial properties. However, the effect of thymol on S. aureus internalization into bovine mammary epithelial cells (bMEC) has not been investigated. In this study, we evaluated the effect of thymol on S. aureus internalization into bMEC, the expression of tracheal antimicrobial peptide (TAP) and β-defensin (BNBD5), and the inhibition of NF-κB activation in bMEC infected with S. aureus. Our results showed that thymol (16-64 μg/ml) could reduce the internalization of S. aureus into bMEC and down-regulate the mRNA expression of TAP and BNBD5 in bMEC infected with S. aureus. In addition, thymol was found to inhibit S. aureus-induced nitric oxide (NO) production in bMEC and suppress S. aureus-induced NF-κB activation in a dose-dependent manner. In conclusion, these results indicated that thymol inhibits S. aureus internalization into bMEC by inhibiting NF-κB activation. Copyright © 2014 Elsevier Ltd. All rights reserved.

In vivo activity of albendazole in combination with thymol against Echinococcus multilocularis.

PubMed

Albani, Clara María; Pensel, Patricia Eugenia; Elissondo, Natalia; Gambino, Guillermo; Elissondo, María Celina

2015-09-15

Human alveolar echinococcosis (AE) is caused by the fox tapeworm Echinococcus multilocularis and is usually lethal if left untreated. The current strategy for treating human AE is surgical resection of the parasite mass complemented by chemotherapy with benzimidazole compounds. However, reliable chemotherapeutic alternatives have not yet been developed stimulating the research of new treatment strategies such as the use of medicinal plants. The aim of the current study was to investigate the efficacy of the combination albendazole (ABZ)+thymol on mice infected with E. multilocularis metacestodes. For this purpose, mice infected with parasite material were treated daily for 20 days with ABZ (5 mg/kg), thymol (40 mg/kg) or ABZ (5 mg/kg)+thymol (40 mg/kg) or left untreated as controls. After mice were euthanized, cysts were removed from the peritoneal cavity and the treatment efficacy was evaluated by the mean cysts weight, viability of protoscoleces and ultrastructural changes of cysts and protoscoleces. The application of thymol or the combination of ABZ+thymol resulted in a significant reduction of the cysts weight compared to untreated mice. We also found that although ABZ and thymol had a scolicidal effect, the combination of the two compounds had a considerably stronger effect showing a reduction in the protoscoleces viability of 62%. These results were also corroborated by optical microscopy, SEM and TEM. Protoscoleces recovered from ABZ or thymol treated mice showed alterations as contraction of the soma region, rostellar disorganization and presence of blebs in the tegument. However both drugs when combined lead to a total loss of the typical morphology of protoscoleces. All cysts removed from control mice appeared intact and no change in ultrastructure was detected. In contrast, cysts developed in mice treated with ABZ revealed changes in the germinal layer as reduction in cell number, while the treatment with thymol or the ABZ+thymol combination predominantly showed presence of cell debris. On the other hand, no differences were found in alkaline phosphatase (AP), glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) activities between control and treated mice, indicating the lack of toxicity of the different drug treatments during the experiment. Because combined ABZ+thymol treatment exhibited higher treatment efficiency compared with the drugs applied separately against murine experimental alveolar echinococcosis, we propose it would be a useful option for the treatment of human AE. Copyright © 2015 Elsevier B.V. All rights reserved.

Fabrication and characterization of novel antimicrobial films derived from thymol-loaded zein-sodium caseinate (SC) nanoparticles.

PubMed

Li, Kang-Kang; Yin, Shou-Wei; Yang, Xiao-Quan; Tang, Chuan-He; Wei, Zi-Hao

2012-11-21

The objective of this research was to fabricate novel antimicrobial films based on zein colloidal nanoparticles coated with sodium caseinate (SC), an emulsifier/stabilizer. Thymol-loaded zein-SC nanoparticles were prepared using an antisolvent technique, with the average particle size and zeta potential about 200 ± 20 nm and -40 mV, respectively. Zein-SC nanoparticle-based films exhibited higher mechanical resistance and water barrier capacity than the SC films and concomitant good extensibility as compared with zein films. Thymol loadings endowed zein-SC nanoparticle-based films with antimicrobial activity against Escherichia coli and Salmonella as well as DPPH radical scavenging activity. Water vapor permeability, microstructure, mechanical, and controlled release properties of the films were evaluated. The possible relationship between some selected physical properties and microstructure were also discussed. Atomic force microscopy (AFM) analysis indicated that thymol loadings resulted in the emergence phenomena of the nanoparticles to form large particles or packed structure, consisting of clusters of nanoparticles, within the film matrix, in a thymol loading dependent manner. The appearance of large particles or an agglomerate of particles may weaken the compactness of protein network of films and thus impair the water barrier capacity, mechanical resistance, and extensibility of the films. The release kinetics of thymol from nanoparticle-based films can be described as a two-step biphasic process, that is, an initial burst effect followed by subsequent slower release, and zein-SC nanoparticles within the films matrices gave them the ability to sustain the release of thymol. In addition, a schematic illustration of the formation pathway of zein-SC nanoparticle-based films with or without thymol was proposed to illuminate the possible relationship between some selected physical properties and the microstructure of the films.

Effects of the essential oil constituent thymol and other neuroactive chemicals on flight motor activity and wing beat frequency in the blowfly Phaenicia sericata.

PubMed

Waliwitiya, Ranil; Belton, Peter; Nicholson, Russell A; Lowenberger, Carl A

2010-03-01

The effects were evaluated of the plant terpenoid thymol and eight other neuroactive compounds on flight muscle impulses (FMIs) and wing beat frequency (WBF) of tethered blowflies (Phaenicia sericata Meig.). The electrical activity of the dorsolongitudinal flight muscles was closely linked to the WBF of control insects. Topically applied thymol inhibited WBF within 15-30 min and reduced FMI frequency. Octopamine and chlordimeform caused a similar, early-onset bursting pattern that decreased in amplitude with time. Desmethylchlordimeform blocked wing beating within 60 min and generated a profile of continuous but lower-frequency FMIs. Fipronil suppressed wing beating and induced a pattern of continuous, variable-frequency spiking that diminished gradually over 6 h. Cypermethrin- and rotenone-treated flies had initial strong FMIs that declined with time. In flies injected with GABA, the FMIs were generally unidirectional and frequency was reduced, as was seen with thymol. Thymol readily penetrates the cuticle and interferes with flight muscle and central nervous function in the blowfly. The similarity of the action of thymol and GABA suggests that this terpenoid acts centrally in blowflies by mimicking or facilitating GABA action.

Antifungal activity and mode of action of thymol and its synergism with nystatin against Candida species involved with infections in the oral cavity: an in vitro study.

PubMed

de Castro, Ricardo Dias; de Souza, Trícia Murielly Pereira Andrade; Bezerra, Louise Morais Dornelas; Ferreira, Gabriela Lacet Silva; Costa, Edja Maria Melo de Brito; Cavalcanti, Alessandro Leite

2015-11-24

Limitations of antifungal agents used in the treatment of oral candidiasis, as the development of resistant strains, are known by the scientific community. In this context, the aim of this study was to evaluate the antifungal activity of thymol against Candida albicans, Candida tropicalis and Candida krusei strains and to determine its mode of action and synergistic effect when combined with the synthetic antifungal nystatin. The minimum inhibitory concentration (MIC) was determined using a microdilution technique, and the minimum fungicidal concentration (MFC) was determined via subculture sowing. The mode of action of thymol was established by verifying fungal growth in the presence of sorbitol or ergosterol. The fractional inhibitory concentration index (FIC) was determined using the checkerboard method. Thymol presented an antifungal effect, with MICs of 39 μg/mL for C. albicans and C. krusei and 78 μg/mL for C. tropicalis. The results of the antifungal test remained unchanged in the presence of sorbitol; however, the MIC value of thymol against C. albicans increased eight times (from 39.0 to 312.5 μg/mL) in presence of exogenous ergosterol. The combination of thymol and nystatin reduced the MIC values of both products by 87.4%, generating an FIC index of 0.25. Thymol was found to have a fungicidal effect on Candida species and a synergistic effect when combined with nystatin.

Insecticidal toxicities of carvacrol and thymol derived from Thymus vulgaris Lin. against Pochazia shantungensis Chou & Lu., newly recorded pest

NASA Astrophysics Data System (ADS)

Park, Jun-Hwan; Jeon, Ye-Jin; Lee, Chi-Hoon; Chung, Namhyun; Lee, Hoi-Seon

2017-01-01

The insecticidal toxicities of five essential oils against Pochazia shantungensis adults and nymphs, newly recorded pests, were evaluated. The LC50 values of Thymus vulgaris, Ruta graveolens, Citrus aurantium, Leptospermum petersonii and Achillea millefolium oils were recorded as 57.48, 84.44, 92.58, 113.26 and 125.78 mg/L, respectively, against P. shantungensis nymphs using the leaf dipping bioassay, and 75.80, 109.86, 113.26, 145.06 and 153.74 mg/L, respectively, against P. shantungensis adults using the spray bioassay method. Regarding volatile components identified in T. vulgaris oil, the LC50 values of carvacrol and thymol using the leaf dipping bioassay against P. shantungensis nymphs were 56.74 and 28.52 mg/L, respectively. The insecticidal action of T. vulgaris oil against P. shantungensis could be attributed to carvacrol and thymol. Based on the structure-toxicity relationship between thymol analogs and insecticidal toxicities against P. shantungensis nymphs similar to the LC50 values against P. shantungensis adults, the LC50 values of thymol, carvacrol, citral, 2-isopropylphenol, 3-isopropylphenol, and 4-isopropylphenol were 28.52, 56.74 and 89.12, 71.41, 82.49, and 111.28 mg/L, respectively. These results indicate that the insecticidal mode of action of thymol analogs may be largely attributed to the methyl functional group. Thymol analogues have promising potential as first-choice insecticides against P. shantungensis adults and nymphs.

Bactericidal action of binary and ternary mixtures of carvacrol, thymol, and eugenol against Listeria innocua.

PubMed

García-García, Rebeca; López-Malo, Aurelio; Palou, Enrique

2011-03-01

The bactericidal effect of 3 natural agents (carvacrol, thymol, and eugenol) was evaluated as well as their binary and ternary mixtures on Listeria innocua inactivation in liquid model systems. Minimal bactericidal concentrations (MBC) of these agents were determined, and then binary and ternary mixtures were evaluated. Culture media were inoculated with L. innocua and incubated for 72 h at 35 °C. Turbidity of studied systems were determined every 24 h. The most effective individual antimicrobial agent was carvacrol, followed by thymol and then eugenol with MBCs of 150, 250, and 450 mg kg(-1), respectively. It was observed that the most effective binary mixture was 75 mg kg(-1) carvacrol and 62.5 mg kg(-1) thymol. Furthermore, the ternary mixture carvacrol-thymol-eugenol in concentrations of 75, 31.25, and 56.25 mg kg(-1), correspondingly, was the most effective for L. innocua inactivation. Several binary and ternary mixtures of these 3 natural antimicrobial agents worked adequately to inactivate L. innocua.

Thymol nanoemulsions incorporated in quinoa protein/chitosan edible films; antifungal effect in cherry tomatoes.

PubMed

Robledo, Nancy; Vera, Paola; López, Luis; Yazdani-Pedram, Mehrdad; Tapia, Cristian; Abugoch, Lilian

2018-04-25

Thymol nanoemulsions were produced by spontaneous emulsification, ultrasound, and a combination of both methods. The best result in terms of size and polydispersion was spontaneous emulsification where thymol was efficiently encapsulated, the nanoemulsions inhibited Botrytis cinerea at 110 ppm of thymol. A 10% dilution of this nanoemulsion in water was used to prepare quinoa-chitosan films. The film microstructure was porous and heterogeneous. The tensile strength of the film was significantly lower but its mean elongation at break was similar to that of the control film. The water vapour permeability was similar to that of the control film. The effect of nanoemulsion-thymol-quinoa protein/chitosan coating on mould growth in inoculated cherry tomatoes was evaluated. Compared with control samples (tomatoes without coating and those coated with quinoa protein/chitosan), tomatoes with this coating and inoculated with B. cinerea showed a significant decrease in fungal growth after 7 days at 5 °C. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fabrication, characterization and antimicrobial activities of thymol-loaded zein nanoparticles stabilized by sodium caseinate-chitosan hydrochloride double layers.

PubMed

Zhang, Yaqiong; Niu, Yuge; Luo, Yangchao; Ge, Mei; Yang, Tian; Yu, Liangli Lucy; Wang, Qin

2014-01-01

Thymol-loaded zein nanoparticles stabilized with sodium caseinate (SC) and chitosan hydrochloride (CHC) were prepared and characterized. The SC stabilized nanoparticles had well-defined size range and negatively charged surface. Due to the presence of SC, the stabilized zein nanoparticles showed a shift of isoelectric point from 6.18 to 5.05, and had a desirable redispersibility in water at neutral pH after lyophilization. Coating with CHC onto the SC stabilized zein nanoparticles resulted in increased particle size, reversal of zeta potential value from negative to positive, and improved encapsulation efficiency. Both thymol-loaded zein nanoparticles and SC stabilized zein nanoparticles had a spherical shape and smooth surface, while the surfaces of CHC-SC stabilized zein nanoparticles seemed rough and had some clumps. Encapsulated thymol was more effective in suppressing gram-positive bacterium than un-encapsulated thymol for a longer time period. Copyright © 2013 Elsevier Ltd. All rights reserved.

The ameliorative effect of thymol against hydrocortisone-induced hepatic oxidative stress injury in adult male rats.

PubMed

Aboelwafa, Hanaa R; Yousef, Hany N

2015-08-01

The aim of the present study was to investigate whether hydrocortisone induces oxidative stress in hepatocytes and to evaluate the possible ameliorative effect of thymol against such hepatic injury. Twenty-four adult male rats were divided into control, thymol, hydrocortisone, and hydrocortisone+thymol groups. The 4 groups were treated daily for 15 days. Hydrocortisone significantly induced oxidative stress in the liver tissues, marked by increased serum levels of alanine transaminase (ALT), aspartate transaminase (AST), total oxidative capacity (TOC), and tumor necrosis factor-alpha (TNF-α) accompanied by marked decline of serum levels of total protein, albumin, and total antioxidant capacity (TAC). Also, marked elevation in the levels of the thiobarbituric acid reactive substances (TBARS) and TNF-α, beside significant decrease in the level of glutathione (GSH) in hepatic tissues were recorded. These biochemical alterations were accompanied by histopathological changes marked by destruction of the normal hepatic architecture, in addition to ultrastructural alterations represented by degenerative features covering almost all the cytoplasmic organelles of the hepatocytes. Supplementation of hydrocortisone-treated rats with thymol reversed most of the biochemical, histological, and ultrastructural alterations. The results of our study confirm that thymol has strong ameliorative effect against hydrocortisone-induced oxidative stress injury in hepatic tissues.

Development of a HS-SPME-GC-MS/MS Method for the Quantitation of Thymol and Carvacrol in Bovine Matrices and To Determine Residue Depletion in Milk and Tissues.

PubMed

Armorini, Sara; Yeatts, James E; Mullen, Keena A E; Mason, Sharon E; Mehmeti, Elmira; Anderson, Kevin L; Washburn, Steve P; Baynes, Ronald E

2016-10-11

Thymol and carvacrol may be present in several phytoceutical products but there are no well-defined methods to measure these compounds in meat and milk from treated animals. U.S. regulatory authorities deem their presence as an adulteration of food. A rapid and sensitive HS-SPME-GC-MS/MS method was developed for the detection of thymol and carvacrol in bovine milk, plasma, liver, kidney, and fat. Inter- and intraday precision values were all less than 15.7 and 20.2% for thymol and carvacrol, respectively. The accuracy was in ranges of 69.9-111.8% for thymol and 74.0-119.2% for carvacrol. With the exception of fat tissue, stability studies showed that both compounds are stable over a 2 month period. A pilot pharmacokinetic study was conducted to evaluate the developed analytical method and to provide initial estimates of thymol and carvacrol depletion in plasma, milk, and several tissues. Treatment of lactating dairy cattle with phytoceutical products containing these substances resulted in low but measurable residue levels at 96 h for liver and 36 h for milk with very short apparent plasma and milk half-lives (<3.0 h).

Sensitive voltammetric determination of thymol in essential oil of Carum copticum seeds using boron-doped diamond electrode.

PubMed

Stanković, Dalibor M

2015-10-01

Essential oil of Carum copticum seeds, obtained from a local shop, was extracted and content of thymol was analyzed using square-wave voltammetry at boron-doped diamond electrode. The effect of various parameters, such as pH of supporting electrolyte and square-wave voltammetric parameters (modulation amplitude and frequency), was examined. In Britton-Robinson buffer solution (pH 4), thymol provided a single and oval-shaped irreversible oxidation peak at +1.13 V versus silver/silver chloride potassium electrode (3M). Under optimal experimental conditions, a plot of peak height against concentration of thymol was found to be linear over the range of 4 to 100μM consisting of two linear ranges: from 4 to 20μM (R(2)=0.9964) and from 20 to 100μM (R(2)=0.9993). The effect of potential interferences such as p-cymene and γ-terpinene (major components in essential oil of C. copticum seeds) was evaluated. Thus, the proposed method displays a sufficient selectivity toward thymol with a detection limit of 3.9μM, and it was successfully applied for the determination of thymol in essential oil of C. copticum seeds. The Prussian blue method was used for validation of the proposed electroanalytical method. Copyright © 2015 Elsevier Inc. All rights reserved.

Characterization of volatile constituents from Origanum onites and their antifungal and antibacterial activity.

PubMed

Altintas, Ayhan; Tabanca, Nurhayat; Tyihák, Erno; Ott, Peter G; Móricz, Agnes M; Mincsovics, Emil; Wedge, David E

2013-01-01

Essential oils obtained by hydrodistillation (HD) and microwave-assisted HD (MWHD) of Origanum onites aerial parts were analyzed by GC and GCIMS. Thirty-one constituents representing 98.6% of the water-distilled oil and 52 constituents representing 99.6% of the microwave-distilled oil were identified. Carvacrol (76.8% HD and 79.2% MWHD) and thymol (4.7% HD and 4.4% MWHD) were characterized as major constituents in both essential oils. Separation of carvacrol and thymol was achieved by overpressured layer chromatography. HPTLC and TLC separations were also compared. Essential oils were evaluated for antifungal activity against the strawberry anthracnose-causing fungal plant pathogens Colletotrichum acutatum, C. fragariae, and C. gloeosporioides using a direct overlay bioautography assay. Furthermore, main oil components carvacrol and thymol were then evaluated for antifungal activity; only carvacrol demonstrated nonselective antifungal activity against the three Colletotrichum species. Thymol and carvacrol were subsequently evaluated in a 96-well microdilution broth assay against Phomopsis obscurans, Fusarium oxysporum, three Colletotrichum species, and Botrytis cinerea. No activity was observed against any of the three Colletotrichum species at or below 30 pM. However, thymol demonstrated antifungal activity and produced 31.7% growth inhibition of P. obscurans at 120 h and 0.3 pM, whereas carvacrol appeared inactive. Thymol and carvacrol at 30 pM showed 51.5 and 36.9% growth inhibition of B. cinerea at 72 h. The mechanism of antibacterial activity was studied in a bioautography-based BioArena system. Thymol and carvacrol showed similar inhibition/killing effect against Bacillus subtilis soil bacteria; the action could be enhanced by the formaldehyde generator and transporter copper (II) ions and could be decreased in the presence of L-arginine, a formaldehyde capturer. Results indicated that Origanum essential oils and its major components thymol and carvacrol appear to generate antimicrobial activity through a mechanism of action where formaldehyde and its reaction products are produced.

Carvacrol as a potent natural acaricide against Dermanyssus gallinae.

PubMed

Tabari, Mohaddeseh Abouhosseini; Youssefi, Mohammad Reza; Barimani, Alireza; Araghi, Atefeh

2015-10-01

Resistance to conventional synthetic pesticides has been widely reported in Dermanyssus gallinae in poultry production systems. Introducing novel acaricides to poultry industry today is more urgent than ever. Research in this field recently focused on plants and plant-derived compounds as acaricides. In the present study, acaricidal activity of three plant bioactive components, carvacrol, thymol, and farnesol, was assessed against D. gallinae and compared with synthetic pesticide permethrin. Mode of acaricidal action was determined by contact toxicity and fumigant toxicity bioassays. Except farnesol which did not cause any mortality, carvacrol and thymol were found to be toxic to D. gallinae with LD50 values of 1 and 3.15 μg/cm(3), respectively. Permethrin gave the LD50 value of 31.95 μg/cm(3) which was less efficient than carvacrol and thymol. In fumigant toxicity bioassay, mortality rate in carvacrol- and thymol-treated groups in closed method was significantly higher than the open one. On the other hand, permethrin exhibited poor fumigant toxicity as there was no statistically significant difference between mortality rate in open and closed methods. These findings revealed that mechanism of acaricidal activity of carvacrol and thymol but not permethrin was mainly due to fumigant action. Results of the present study suggested that carvacrol and thymol, especially carvacrol, can be developed as a novel potent bioacaricide against D. gallinae.

Chemical composition, larvicidal action, and adult repellency of Thymus magnus against Aedes albopictus.

PubMed

Park, Young-Uk; Koo, Hyun-Na; Kim, Gil-Hah

2012-09-01

Thymus magnus, an endemic species, is found in the Republic of Korea. The volatile compounds extracted by SPME from T. magnus were investigated for their chemical composition and electrophysiological response against the Asian tiger mosquito, Aedes albopictus. The volatile compounds of T. magnus as determined by gas chromatography mass spectrometry were gamma-terpinene (33.0%), thymol (29.9%), beta-bisabolene (8.9%), p-cymene (8.3%), alpha-terpinene (5.0%), myrcene (4.7%), beta-caryophyllene (4.0%), alpha-thujene (2.7%), camphene (1.3%), carvacrol (1.2%), and alpha-pinene (1.1%). Among these candidates, thymol exhibited complete (100%) repellent activity against female Ae. albopictus, an effect that was confirmed through evaluating the electrophysiological response on the antenna of Ae. albopictus. The effectiveness of a binary 1:2 mixture of thymol and vanillin (0.05:0.1 microl per cm2) was found to be significantly more effective than thymol alone for a period of 120 min. In addition, thymol, alpha-terpinene, and carvacrol showed high larvicidal activity against on the third-stage larvae with LC50 values of 0.9 microl per 100 ml.

Antibacterial and antifungal activities of thymol: A brief review of the literature.

PubMed

Marchese, Anna; Orhan, Ilkay Erdogan; Daglia, Maria; Barbieri, Ramona; Di Lorenzo, Arianna; Nabavi, Seyed Fazel; Gortzi, Olga; Izadi, Morteza; Nabavi, Seyed Mohammad

2016-11-01

Thymol (2-isopropyl-5-methylphenol) is the main monoterpene phenol occurring in essential oils isolated from plants belonging to the Lamiaceae family (Thymus, Ocimum, Origanum, and Monarda genera), and other plants such as those belonging to the Verbenaceae, Scrophulariaceae, Ranunculaceae, and Apiaceae families. These essential oils are used in the food industry for their flavouring and preservative properties, in commercial mosquito repellent formulations for their natural repellent effect, in aromatherapy, and in traditional medicine for the treatment of headaches, coughs, and diarrhea. Many different activities of thymol such as antioxidant, anti-inflammatory, local anaesthetic, antinociceptive, cicatrizing, antiseptic, and especially antibacterial and antifungal properties have been shown. This review aims to critically evaluate the available literature regarding the antibacterial and antifungal effects of thymol. Copyright © 2016 Elsevier Ltd. All rights reserved.

Milk and plasma disposition of thymol following intramammary administration of a phytoceutical mastitis treatment.

PubMed

McPhee, C S; Anderson, K L; Yeatts, J L; Mason, S E; Barlow, B M; Baynes, R E

2011-04-01

Despite the recent growth of the organic dairy industry, organic producers and veterinarians have limited information when choosing mastitis treatments for animals in organic dairy production. Organic producers commonly administer homeopathic or other plant-based products without having research evaluating the efficacy of these products and using estimated or no withholding times to treat mastitis and other health problems in their herds. In this pilot study, we attempted to identify several active ingredients of Phyto-Mast (Penn Dutch Cow Care, Narvon, PA), a plant-based mastitis treatment used on organic dairy farms, and to quantify the product residue in milk and plasma after intramammary administration. We developed an assay to quantify thymol (one of the active ingredients in Phyto-Mast) in milk and plasma using gas chromatography and mass spectrometry (GC-MS). Thymol is a volatile aromatic compound with antiinflammatory properties. As a model for dairy cows, 5 healthy, lactating alpine dairy goats were given 5 mL of Phyto-Mast per udder half. For 10 d following treatment, we analyzed blood and milk samples for thymol residues using GC-MS. The GC-MS assay was very sensitive for thymol detection, to a concentration of 0.01 μg/mL in plasma. Using thymol as a marker, Phyto-Mast was detectable and quantifiable in plasma beginning with the 15-min posttreatment sample, but was no longer detectable in the 4-h posttreatment sample. Thymol residues were only detected in the 12-h posttreatment milk sample. An inflammatory response was not evident in the udder following phytoceutical administration. Although this study provides information about the elimination of thymol, the product contains several other active chemicals, which may have different pharmacokinetic behaviors. Further analysis and additional study animals will help to determine a milk withholding time for Phyto-Mast. Given the recent growth of the organic dairy industry, understanding the pharmacokinetics of therapeutics used in organic production and developing accurate withholding recommendations will help to ensure milk safety. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Structurally Related Monoterpenes p-Cymene, Carvacrol and Thymol Isolated from Essential Oil from Leaves of Lippia sidoides Cham. (Verbenaceae) Protect Mice against Elastase-Induced Emphysema.

PubMed

Games, Ellen; Guerreiro, Marina; Santana, Fernanda R; Pinheiro, Nathalia M; de Oliveira, Emerson A; Lopes, Fernanda D T Q S; Olivo, Clarice R; Tibério, Iolanda F L C; Martins, Mílton A; Lago, João Henrique G; Prado, Carla M

2016-10-20

Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow obstruction and inflammation. Natural products, such as monoterpenes, displayed anti-inflammatory and anti-oxidant activities and can be used as a source of new compounds to COPD treatment. Our aim was to evaluate, in an elastase-induced pulmonary emphysema in mice, the effects of and underlying mechanisms of three related natural monoterpenes ( p -cymene, carvacrol and thymol) isolated from essential oil from leaves Lippia sidoides Cham. (Verbenaceae). Mices received porcine pancreatic elastase (PPE) and were treated with p -cymene, carvacrol, thymol or vehicle 30 min later and again on 7th, 14th and 28th days. Lung inflammatory profile and histological sections were evaluated. In the elastase-instilled animals, the tested monoterpenes reduced alveolar enlargement, macrophages and the levels of IL-1β, IL-6, IL-8 and IL-17 in bronchoalveolar lavage fluid (BALF), and collagen fibers, MMP-9 and p-65-NF-κB-positive cells in lung parenchyma ( p < 0.05). All treatments attenuated levels of 8-iso-PGF2α but only thymol was able to reduced exhaled nitric oxide ( p < 0.05). Monoterpenes p -cymene, carvacrol and thymol reduced lung emphysema and inflammation in mice. No significant differences among the three monoterpenes treatments were found, suggesting that the presence of hydroxyl group in the molecular structure of thymol and carvacrol do not play a central role in the anti-inflammatory effects.

Development of a polydimethylsiloxane-thymol/nitroprusside composite based sensor involving thymol derivatization for ammonium monitoring in water samples.

PubMed

Prieto-Blanco, M C; Jornet-Martínez, N; Moliner-Martínez, Y; Molins-Legua, C; Herráez-Hernández, R; Verdú Andrés, J; Campins-Falcó, P

2015-01-15

This report describes a polydimethylsiloxane (PDMS)-thymol/nitroprusside delivery composite sensor for direct monitoring of ammonium in environmental water samples. The sensor is based on a PDMS support that contains the Berthelot's reaction reagents. To prepare the PDMS-thymol/nitroprusside composite discs, thymol and nitroprusside have been encapsulated in the PDMS matrix, forming a reagent release support which significantly simplifies the analytical measurements, since it avoids the need to prepare derivatizing reagents and sample handling is reduced to the sampling step. When, the PDMS-thymol/nitroprusside composite was introduced in water samples spontaneous release of the chromophore and catalyst was produced, and the derivatization reaction took place to form the indothymol blue. Thus, qualitative analysis of NH4(+) could be carried out by visual inspection, but also, it can be quantified by measuring the absorbance at 690 nm. These portable devices provided good sensitivity (LOD<0.4 mg L(-1)) and reproducibility (RSD <10%) for the rapid detection of ammonium. The PDMS-NH4(+) sensor has been successfully applied to determine ammonium in water samples and in the aqueous extracts of particulate matter PM10 samples. Moreover, the reliability of the method for qualitative analysis has been demonstrated. Finally, the advantages of the PDMS-NH4(+) sensor have been examined by comparing some analytical and complementary characteristics with the properties of well-established ammonium determination methods. Copyright © 2014 Elsevier B.V. All rights reserved.

Short communication: Interaction of the isomers carvacrol and thymol with the antibiotics doxycycline and tilmicosin: In vitro effects against pathogenic bacteria commonly found in the respiratory tract of calves.

PubMed

Kissels, W; Wu, X; Santos, R R

2017-02-01

Bovine respiratory disease is the major problem faced by cattle, specially calves, leading to reduced animal performance and increased mortality, consequently causing important economic losses. Hence, calves must be submitted to antibiotic therapy to counteract this infection usually initiated by the combination of environmental stress factors and viral infection, altering the animal's defense mechanism, and thus allowing lung colonization by the opportunistic bacteria Mannheimia haemolytica and Pasteurella multocida. Essential oils appear to be candidates to replace antibiotics or to act as antibiotic adjuvants due to their antimicrobial properties. In the present study, we aimed to evaluate the 4 essential oil components carvacrol, thymol, trans-anethole, and 1,8 cineole as antibacterial agents or as adjuvants for the antibiotics doxycycline and tilmicosin against M. haemolytica and P. multocida. Bacteria were cultured according to standard protocols, followed by the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration. A checkerboard assay was applied to detect possible interactions between components, between antibiotics, and between components and antibiotics. Doxycycline at 0.25 and 0.125 μg/mL inhibited the growth of P. multocida and M. haemolytica, respectively, whereas tilmicosin MIC values were 1.0 and 4.0 μg/mL for P. multocida and M. haemolytica, respectively. Carvacrol MIC values were 2.5 and 1.25 mM for P. multocida and M. haemolytica, respectively, whereas thymol MIC values were 1.25 and 0.625 mM for P. multocida and M. haemolytica, respectively. Trans-anethole and 1,8 cineole did not present any antibacterial effect even at 40 mM against the investigated pathogens. All minimum bactericidal concentration values were the same as MIC, except when thymol was tested against M. haemolytica, being twice the MIC data (i.e., 1.25 mM thymol). Based on fractional inhibitory concentration checkerboard assay, no interaction was observed between doxycycline and tilmicosin. Carvacrol and thymol presented an additive effect when one of them was combined with tilmicosin. Additive effect was also observed when doxycycline was combined with thymol. Synergism was observed when carvacrol was combined with doxycycline or with thymol. Although the antibacterial effects of the tested essential oil components were observed at high concentrations for in vitro conditions, the additive and synergic effects of carvacrol and thymol with antibiotics suggest the option to apply them as antibiotic adjuvants. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Thymol Elicits HCT-116 Colorectal Carcinoma Cell Death Through Induction of Oxidative Stress.

PubMed

Chauhan, Anil Kumar; Bahuguna, Ashutosh; Paul, Souren; Kang, Sun Chul

2018-02-07

Colon cancer is one of the most deadly and common carcinomas occurring worldwide and there have been many attempts to treat this cancer. The present work was designed in order to evaluate thymol as a potent drug against colon cancer. Cytotoxicity of thymol at different concentrations was evaluated against a human colon carcinoma cell line (HCT-116 cells). Fluorescent staining was carried out to evaluate the level of ROS as well as mitochondrial and DNA fragmentation and immunoblot analysis were performed to confirm apoptosis and mitoptosis. Results of the study demonstrated that thymol efficiently created an oxidative stress environment inside HCT-116 cells, a colorectal carcinoma cell line, through induction of ROS production along with intense damage to DNA and mitochondria, as observed through Hoechst and rhodamine 123 staining, respectively. Moreover, expression of PARP-1, p-JNK, cytochrome-C and caspase-3 proteins was up-regulated, suggesting HCT-116 cells underwent mitoptotic cell death. Therefore, thymol could be used as a potent drug against colon cancer due to its lower toxicity and prevalence in natural medicinal plants. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Phase behavior, microstructural transition, antimicrobial and antioxidant activities of a water-dilutable thymol microemulsion.

PubMed

Deng, Lingli; Taxipalati, Maierhaba; Sun, Ping; Que, Fei; Zhang, Hui

2015-12-01

Pseudo ternary phase diagrams were constructed to assess the dilutability of thymol microemulsions using non-ionic (Tween 80), cationic (CTAB), and anionic (SDS) surfactants. We successfully constructed a thymol U-type microemulsion system using Tween 80 as surfactant and studied the microstructural transition along the dilution line at a 90/10 surfactant/oil mass ratio, with thymol and ethanol (3:1, w/w) as the oil phase. Differential scanning calorimetry analysis suggested that the microemulsions gradually inverted from the water-in-oil (W/O) (0-20% water) to the bicontinuous (25-35% water), and finally to the oil-in-water (O/W) (40-90% water) microstructures upon dilution, in good agreement with the conductivity measurements, while the rheological results indicated the collapse of rod-like micelles followed by formation of spherical micelles in the O/W region. The activities of the U-type thymol microemulsions are structural dependent. The antimicrobial activity against Escherichia coli and Staphylococcus aureus decreased when the microemulsions transformed from W/O to bicontinuous and O/W structures, while the DPPH scavenging activity increased. Copyright © 2015 Elsevier B.V. All rights reserved.

In Vitro Control of Post-Harvest Fruit Rot Fungi by Some Plant Essential Oil Components

PubMed Central

Camele, Ippolito; Altieri, Luciana; De Martino, Laura; De Feo, Vincenzo; Mancini, Emilia; Rana, Gian Luigi

2012-01-01

Eight substances that are main components of the essential oils from three Mediterranean aromatic plants (Verbena officinalis, Thymus vulgaris and Origanum vulgare), previously found active against some phytopathogenic Fungi and Stramenopila, have been tested in vitro against five etiological agents of post-harvest fruit decay, Botrytis cinerea, Penicillium italicum, P. expansum, Phytophthora citrophthora and Rhizopus stolonifer. The tested compounds were β-fellandrene, β-pinene, camphene, carvacrol, citral, o-cymene, γ-terpinene and thymol. Citral exhibited a fungicidal action against P. citrophthora; carvacrol and thymol showed a fungistatic activity against P. citrophthora and R. stolonifer. Citral and carvacrol at 250 ppm, and thymol at 150 and 250 ppm stopped the growth of B. cinerea. Moreover, thymol showed fungistatic and fungicidal action against P. italicum. Finally, the mycelium growth of P. expansum was inhibited in the presence of 250 ppm of thymol and carvacrol. These results represent an important step toward the goal to use some essential oils or their components as natural preservatives for fruits and foodstuffs, due to their safety for consumer healthy and positive effect on shelf life extension of agricultural fresh products. PMID:22408454

The impact of cooking and delivery modes of thymol and carvacrol on retention and bioaccessibility in starchy foods.

PubMed

Aravena, Gabriela; García, Olga; Muñoz, Ociel; Pérez-Correa, José R; Parada, Javier

2016-04-01

Oregano and thyme possess beneficial properties for human health, mainly attributable to monoterpenes such as thymol and carvacrol. The main objective of this research was to assess, on starchy food, the impact of cooking (boiling and baking) and delivery (ground leaves and essential oil) modes on retention and bioaccessibility of thymol and carvacrol. Retention was assessed after cooking, while bioaccessibility was estimated in cooked samples using an in vitro digestion model. Our results indicate that bioaccessibility was weakly dependent on cooking and delivery modes (27-33%). Boil cooking presented 20% more retention than baking for both compounds. When essential oil was added to the food matrix, thymol was retained almost 25% more when compared with ground leaves' addition. Conversely, carvacrol was retained 39% more when ground leaves were added. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thymol, a dietary monoterpene phenol abrogates mitochondrial dysfunction in β-adrenergic agonist induced myocardial infarcted rats by inhibiting oxidative stress.

PubMed

Nagoor Meeran, M F; Jagadeesh, G S; Selvaraj, P

2016-01-25

Mitochondrial dysfunction has been suggested to be one of the important pathological events in isoproterenol (ISO), a synthetic catecholamine and β-adrenergic agonist induced myocardial infarction (MI). In this context, we have evaluated the impact of thymol against ISO induced oxidative stress and calcium uniporter malfunction involved in the pathology of mitochondrial dysfunction in rats. Male albino Wistar rats were pre and co-treated with thymol (7.5 mg/kg body weight) daily for 7 days. Isoproterenol (100 mg/kg body weight) was subcutaneously injected into rats on 6th and 7th day to induce MI. To explore the extent of cardiac mitochondrial damage, the activities/levels of cardiac marker enzymes, mitochondrial lipid peroxidation products, antioxidants, lipids, calcium, adenosine triphosphate and multi marker enzymes were evaluated. Isoproterenol induced myocardial infarcted rats showed a significant increase in the activities of cardiac diagnostic markers, heart mitochondrial lipid peroxidation, lipids, calcium, and a significant decrease in the activities/levels of heart mitochondrial superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, isocitrate, malate, α-ketoglutarate and NADH-dehydrogenases, cytochrome-C-oxidase, and adenosine triphosphate. Thymol pre and co-treatment showed near normalized effects on all the biochemical parameters studied. Transmission electron microscopic findings and mitochondrial swelling studies confirmed our biochemical findings. The in vitro study also revealed the potent free-radical scavenging activity of thymol. Thus, thymol attenuates the involvement of ISO against oxidative stress and calcium uniporter malfunction associated with mitochondrial dysfunction in rats. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Antioxidant, Antibacterial, and Cytotoxic Activities of the Ethanolic Origanum vulgare Extract and Its Major Constituents

PubMed Central

Coccimiglio, John; Alipour, Misagh; Jiang, Zi-Hua; Gottardo, Christine

2016-01-01

Oregano is a perennial shrub that grows in the mountains of the Mediterranean and Euro/Irano-Siberian regions. This study was conducted to identify the major constituents of the ethanolic Origanum vulgare extract and examine the cytotoxic, antioxidant, and antibacterial properties of the extract but more importantly the contribution of its specific major constituent(s) or their combination to the overall extract biological activity. Gas chromatography/mass spectroscopy analysis showed that the extract contained monoterpene hydrocarbons and phenolic compounds, the major ones being carvacrol and thymol and to a lesser extent p-cymene, 1-octacosanol, creosol, and phytol. A549 epithelial cells challenged with the extract showed a concentration-dependent increase in cytotoxicity. A combination of thymol and carvacrol at equimolar concentrations to those present in the extract was less cytotoxic. The A549 cells pretreated with nonlethal extract concentrations protected against hydrogen-peroxide-induced cytotoxicity, an antioxidant effect more effective than the combination of equimolar concentrations of thymol/carvacrol. Inclusion of p-cymene and/or 1-octacosanol did not alter the synergistic antioxidant effects of the carvacrol/thymol mixture. The extract also exhibited antimicrobial properties against Gram-positive and Gram-negative bacterial strains including clinical isolates. In conclusion, the oregano extract has cytotoxic, antioxidant, and antibacterial activities mostly attributed to carvacrol and thymol. PMID:27051475

Antifungal Activity of Some Constituents of Origanum vulgare L. Essential Oil Against Postharvest Disease of Peach Fruit.

PubMed

Elshafie, Hazem S; Mancini, Emilia; Sakr, Shimaa; De Martino, Laura; Mattia, Carlo Andrea; De Feo, Vincenzo; Camele, Ippolito

2015-08-01

Plant essential oils (EOs) can potentially replace synthetic fungicides in the management of postharvest fruit and vegetable diseases. The aim of this study was to evaluate in vitro and in vivo effectiveness of thymol, carvacrol, linalool, and trans-caryophyllene, single constituents of the EO of Origanum vulgare L. ssp. hirtum against Monilinia laxa, M. fructigena, and M. fructicola, which are important phytopathogens and causal agents of brown rot of pome and stone fruits in pre- and postharvest. Moreover, the possible phytotoxic activity of these constituents was assessed and their minimum inhibitory concentration (MIC) was determined. In vitro experiment indicated that thymol and carvacrol possess the highest antifungal activity. Results of in vivo trials confirmed the strong efficacy of thymol and carvacrol against brown rot of peach fruits. The thymol MIC resulted to be 0.16 μg/μL against M. laxa and M. fructigena and 0.12 μg/μL against M. fructicola, whereas for carvacrol they were 0.02 μg/μL against the first two Monilinia species and 0.03 μg/μL against the third. Results of this study indicated that thymol and carvacrol could be used after suitable formulation for controlling postharvest fruit diseases caused by the three studied Monilinia species.

Antimicrobial Effect of Lippia sidoides and Thymol on Enterococcus faecalis Biofilm of the Bacterium Isolated from Root Canals

PubMed Central

Veras, H. N. H.; Rodrigues, F. F. G.; Botelho, M. A.; Menezes, I. R. A.; Coutinho, H. D. M.; da Costa, J. G. M.

2014-01-01

The species Lippia sidoides Cham. (Verbenaceae) is utilized in popular medicine as a local antiseptic on the skin and mucosal tissues. Enterococcus faecalis is the bacterium isolated from root canals of teeth with persistent periapical lesions and has the ability to form biofilm, where it is responsible for the failure of endodontic treatments. Essential oil of L. sidoides (EOLS) and its major component, thymol, were evaluated for reducing the CFU in biofilms of E. faecalis in vitro. The essential oil was obtained by hydrodistillation and examined with respect to the chemical composition, by gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis has led to the identification of thymol (84.9%) and p-cymene (5.33%). EOLS and thymol reduced CFU in biofilms of E. faecalis in vitro (time of maturation, 72 h), with an exposure time of 30 and 60 min at concentrations of 2.5 and 10%. There was no statistical difference in effect between EOLS and thymol, demonstrating that this phenolic monoterpene was the possible compound responsible for the antimicrobial activity of EOLS. This study provides a basis for the possible utilization of EOLS as an adjuvant in the treatment of root canals that show colonization by E. faecalis. PMID:24683344

Blending lecithin and gelatin improves the formation of thymol nanodispersions.

PubMed

Xue, Jia; Zhong, Qixin

2014-04-02

Delivery systems of lipophilic antimicrobials such as thymol prepared with generally recognized-as-safe ingredients are needed to enhance the microbiological safety of low-acid (pH > 4.6) foods. Nanodispersions with particle diameters below 100 nm are particularly demanded because of the low turbidity and physical stability. In this study, thymol dispersions were prepared by gelatin and soy lecithin on an individual basis or in combination. Dispersions prepared with the lecithin-gelatin blend were translucent and stable at pH 5.0-8.0, contrasting with turbid and unstable dispersions when the emulsifiers were used individually. The synergistic surface activity of gelatin and lecithin was due to complex formation that effectively prevented particle size change due to coalescence and Ostwald ripening. Electrostatic interactions were observed to be the colloidal force responsible for preventing particle aggregation. The studied generally recognized-as-safe nanodispersions have great potential to deliver lipophilic antimicrobials such as thymol in low-acid foods to enhance food safety.

Effect of thymol in heating and recovery media on the isothermal and non-isothermal heat resistance of Bacillus spores.

PubMed

Esteban, Maria-Dolores; Conesa, Raquel; Huertas, Juan-Pablo; Palop, Alfredo

2015-06-01

Members of the genus Bacillus include important food-borne pathogen and spoilage microorganisms for food industry. Essential oils are natural products extracted from herbs and spices, which can be used as natural preservatives in many foods because of their antibacterial, antifungal, antioxidant and anti-carcinogenic properties. The aim of this research was to explore the effect of the addition of different concentrations of thymol to the heating and recovery media on the thermal resistance of spores of Bacillus cereus, Bacillus licheniformis and Bacillus subtilis at different temperatures. While the heat resistance was hardly reduced when thymol was present in the heating medium, the effect in the recovery medium was greater, reducing the D100 °C values down to one third for B. subtilis and B. cereus when 0.5 mM thymol was added. This effect was dose dependent and was also observed at other heating temperatures. Copyright © 2014 Elsevier Ltd. All rights reserved.

Shelf life of ready to use peeled shrimps as affected by thymol essential oil and modified atmosphere packaging.

PubMed

Mastromatteo, Marianna; Danza, Alessandra; Conte, Amalia; Muratore, Giuseppe; Del Nobile, Matteo Alessandro

2010-12-15

In this work the influence of different packaging strategies on the shelf life of ready to use peeled shrimps was investigated. First, the effectiveness of the coating (Coat) and the active coating loaded with different concentrations of thymol (Coat-500, Coat-1000, and Coat-1500) on the quality loss of the investigated food product packaged in air was addressed; afterwards, the thymol concentration that had shown the best performance was used in combination with MAP (5% O(2); 95% CO(2)). Microbial cell load of main spoilage microorganisms, pH and sensorial quality were monitored during the refrigerated storage. Results of the first step suggested that the sole coating did not affect the microbial growth. A slight antimicrobial effect was obtained when the coating was loaded with thymol and a concentration dependence was also observed. Moreover, the active coating was effective in minimizing the sensory quality loss of the investigated product, it was particularly true at the lowest thymol concentration. In the second step, the thymol concentration (1000 ppm) that showed the strike balance between microbial and sensorial quality was chosen in combination with MAP. As expected, MAP significantly affected the growth of the mesophilic bacteria. In particular, a cell load reduction of about 2 log cycle for the samples under MAP respect to that in air was obtained. Moreover, the MAP packaging inhibited the growth of the Pseudomonas spp. and hydrogen sulphide-producing bacteria. The MAP alone was not able to improve the shelf life of the uncoated samples. In fact, no significant difference between the control samples packaged in air and MAP was observed. Whilst, the use of coating under MAP condition prolonged the shelf life of about 6 days with respect to the same samples packaged in air. Moreover, when the MAP was used in combination with thymol, a further shelf life prolongation with respect to the samples packaged in air was observed. In particular, a shelf life of about 14 days for the active coating under MAP compared to the same samples in air (5 days) was obtained. Copyright © 2010 Elsevier B.V. All rights reserved.

Efficacy of albendazole in combination with thymol against Echinococcus multilocularis protoscoleces and metacestodes.

PubMed

María, Albani Clara; Celina, Elissondo María

2014-12-01

The larval (metacestode) stage of the tapeworm Echinococcus multilocularis causes alveolar echinococcosis (AE), a mainly hepatic disease characterized by continuous asexual proliferation of metacestodes by exogenous budding, resulting in the tumor-like, infiltrative growth of the parasite lesion. Current chemotherapeutical treatment of AE relies on the use of benzimidazoles, albendazole (ABZ) and mebendazole, but these drugs act parasitostatic rather than parasitocidal, and due to their low success rate they imply a lifelong application causing severe side effects. Thymol is one of the major components of the essential oils of Thymus and is a widely known anti-microbial agent. The aim of the present work was to compare the efficacy of albendazole (ABZ) and thymol separately or combined on E. multilocularis protoscoleces and metacestodes. For this purpose, microscopical examinations at different time points were carried out. Moreover the tegumentary enzyme gamma glutamyl transferase (GGT) was measured to quantify the damage in metacestodes. Even though treatments of in vitro cultured E. multilocularis protoscoleces or metacestodes with ABZ or/and thymol showed that the drugs have an adverse effect on parasite viability, the combination of the two compounds at the concentration of 10μg/ml showed the maximum anti-parasitic effect. Three days postincubation the first effects of the treatment were detected on protoscoleces and a marked reduction in viability (33%) was registered at day 18. Incubation of E. multilocularis metacestodes in the presence of ABZ 10μg/ml+thymol 10μg/ml during 10 days resulted in dramatic alterations such as strongly irregular and fissured surface and markedly disrupted vesicles. Scanning electron microscopy showed that protoscoleces as well as the germinal layer of E. multilocularis metacestodes were dramatically damaged following ABZ or/and thymol treatment. Also an important increase of tegumentary enzyme GGT was registered after 72h postincubation with both drugs. The data reported in this article demonstrate a clear in vitro effect of ABZ+thymol against E. multilocularis protoscoleces and metacestodes. Copyright © 2014 Elsevier B.V. All rights reserved.

Lethal and sublethal effects of essential oil of Lippia sidoides (Verbenaceae) and monoterpenes on Chagas’ disease vector Rhodnius prolixus

PubMed Central

Figueiredo, Marcela B; Gomes, Geovany A; Santangelo, Jayme M; Pontes, Emerson G; Azambuja, Patricia; Garcia, Elói S; de Carvalho, Mário G

2016-01-01

The aim of this study was to identify the composition of the essential oil from leaves of Lippia sidoides (EOLS), a typical shrub commonly found in the dry northeast of Brazil, popularly known as “alecrim-pimenta”. Additionally, we investigated the nymphicidal, ovicidal, phagoinhibitory and excretion effects of EOLS, its major constituent thymol and its isomer carvacrol, on fourth instar nymphs and eggs of Rhodnius prolixus, the Chagas’ disease vector. The nymphicidal and ovicidal activity of thymol, carvacrol, and EOLS was assessed by tests using impregnated Petri dishes. The lethal concentration values (LC50) for EOLS, carvacrol, and thymol were 54.48, 32.98, and 9.38 mg/cm2, respectively. The ovicidal test showed that both carvacrol and thymol (50 mg/cm2) inhibited hatching (50% and 23.3%, respectively), while treatments with 10 mg/cm2 or 50 mg/cm2 EOLS did not affect the hatching rate at all (80% and 90%, respectively). We observed an anti-feeding effect in insects fed with blood containing natural products at the higher concentrations (100 µg/mL). Finally, excretion rate was affected by EOLS and carvacrol, but not by thymol. These findings offer novel insights into basic physiological processes that make the tested natural compounds interesting candidates for new types of insecticides. PMID:27878214

Altered elementary calcium release events and enhanced calcium release by thymol in rat skeletal muscle.

PubMed

Szentesi, Péter; Szappanos, Henrietta; Szegedi, Csaba; Gönczi, Monika; Jona, István; Cseri, Julianna; Kovács, László; Csernoch, László

2004-03-01

The effects of thymol on steps of excitation-contraction coupling were studied on fast-twitch muscles of rodents. Thymol was found to increase the depolarization-induced release of calcium from the sarcoplasmic reticulum, which could not be attributed to a decreased calcium-dependent inactivation of calcium release channels/ryanodine receptors or altered intramembrane charge movement, but rather to a more efficient coupling of depolarization to channel opening. Thymol increased ryanodine binding to heavy sarcoplasmic reticulum vesicles, with a half-activating concentration of 144 micro M and a Hill coefficient of 1.89, and the open probability of the isolated and reconstituted ryanodine receptors, from 0.09 +/- 0.03 to 0.22 +/- 0.04 at 30 micro M. At higher concentrations the drug induced long-lasting open events on a full conducting state. Elementary calcium release events imaged using laser scanning confocal microscopy in the line-scan mode were reduced in size, 0.92 +/- 0.01 vs. 0.70 +/- 0.01, but increased in duration, 56 +/- 1 vs. 79 +/- 1 ms, by 30 micro M thymol, with an increase in the relative proportion of lone embers. Higher concentrations favored long events, resembling embers in control, with duration often exceeding 500 ms. These findings provide direct experimental evidence that the opening of a single release channel will generate an ember, rather than a spark, in mammalian skeletal muscle.

Phyto-fungicides: Structure activity relationships of the thymol derivatives against Rhizoctonia solani

USDA-ARS?s Scientific Manuscript database

Thymol, the key component of thyme oil and its derivatives were evaluated for their structure activity relationship as fungicide against Rhizoctonia solani. Since plant based chemicals are considered as “Generally Recognized as Safe” (GRAS) chemicals, there is a great potential to use phytochemicals...

Organic acids and thymol: unsuitable alternative control of Aethina tumida Murray (Coleoptera: Nitidulidae)

USDA-ARS?s Scientific Manuscript database

To explore alternative small hive beetle control strategies, established Varroa destructor and Galleria mellonella treatments with organic acids (formic, lactic, oxalic and acetic) and thymol were investigated in the laboratory against eggs, larvae and adult small hive beetle (SHB). As formic and ox...

Antagonistic effects of lipids against the bactericidal activity of thymol-beta-D-glucopyranoside

USDA-ARS?s Scientific Manuscript database

The gut of food-producing animals is a reservoir for zoonotic pathogens. Thymol is bactericidal against Salmonella, E. coli, and Campylobacter, but its rapid absorption from the proximal gut reveals a need for protective technologies to deliver effective concentrations to the lower gut where the pa...

[Determination of carvacrol and thymol in Mosla chinensis by HPLC].

PubMed

Ji, Li; Wang, Fang; Liu, Yuan-yan; Tong, Yan; Li, Xian-duan; Feng, Xue-feng; Huang, Lu-qi; Zhou, Guo-ping

2004-11-01

To establish a quantitative method of determination of carvacrol and thymol in Mosla chinensis. The sample was extracted with 95% ethanol, ODS column was used with methanol-water-acetic acid (60:40:2) as mobile phase. The detection wavelength was set at 274 nm. The linearities of carvacrol and thymol were respectively in the range of 0.23-2.15 microg (r = 0.9999) and 0.39-2.36 microg (r = 0.9999); the average recoveries were 99.9% (RSD 1.4%) and 98.6% (RSD 1.3%); the RSD of repeatability were 1.1% and 1.6%. The method is reliable, and can be used for quality control of M. chinensis.

Inhibitory Effects of Emodin, Thymol, and Astragalin on Leptospira interrogans-Induced Inflammatory Response in the Uterine and Endometrium Epithelial Cells of Mice.

PubMed

Zhang, Wenlong; Lu, Xiaojie; Wang, Wei; Ding, Zhuang; Fu, Yunhe; Zhou, Xiaofei; Zhang, Naisheng; Cao, Yongguo

2017-04-01

Leptospirosis is a systemic infection that causes, among others, acute kidney injury, acute liver disease, muscle pain, vasculitis, bleeding disorders, and reproductive loss. In an effort to reduce uterine inflammatory responses induced by Leptospira, we evaluated the anti-inflammation effects of emodin, thymol, and astragalin in a mouse model. Our results showed that treatment with emodin, thymol, and astragalin alleviated uterine inflammation induced by leptospira infection via suppression of pro-inflammatory cytokine expression and prevented tissue damage. Furthermore, we used primary endometrium epithelial cells to show that treatment with these chemicals inhibited the expression of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 using enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. Western blot results showed that these chemicals suppressed the phosphorylation of p38, p65, extracellular signal-regulated kinase, and c-Jun N-terminal kinase. These results indicate that treatment with emodin, thymol, and astragalin suppressed inflammatory response by regulating NF-κB and mitogen-activated protein kinase signaling pathways in leptospira-infected uterine and endometrium epithelial cells of mice.

2,3-Dideoxyglucosides of selected terpene phenols and alcohols as potent antifungal compounds.

PubMed

James Bound, D; Murthy, Pushpa S; Srinivas, P

2016-11-01

The antifungal activities of novel 2,3-unsaturated and 2,3-dideoxy 1-O-glucosides of carvacrol, thymol, and perillyl alcohol were tested against Aspergillus flavus, Aspergillus ochraceus, Fusarium oxysporum, Saccharomyces cerevisiae and Candida albicans. In the agar well diffusion tests, zones of inhibition for the derivatives of carvacrol, thymol and perillyl alcohol were higher (15-30mm) in the case of filamentous fungi than those for the parent compounds. Their MIC and MFC values indicated that the 2,3-unsaturated and 2,3-dideoxy 1-O-glucosides of carvacrol and thymol exhibited more fungicidal activity than the other compounds. Further, the 2,3-dideoxyglucosides of carvacrol and thymol, exhibited antitoxigenic effects against A. ochraceus and A. flavus and inhibited the production of ochratoxin and aflatoxin-B2. Propidium iodide influx assay demonstrated the lysis of C. albicans cells by carvacrol and its 2,3-unsaturated 1-O-glucoside and the loss of the membrane integrity. These new 2,3-dideoxyglucosides can be useful as antifungal agents and condiments in foods. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acaricidal activity of thymol against larvae of Rhipicephalus microplus (Acari: Ixodidae) under semi-natural conditions.

PubMed

Araújo, Laryssa Xavier; Novato, Tatiane Pinheiro Lopes; Zeringota, Viviane; Matos, Renata Silva; Senra, Tatiane Oliveira Souza; Maturano, Ralph; Prata, Márcia Cristina Azevedo; Daemon, Erik; Monteiro, Caio Márcio Oliveira

2015-09-01

This is the first study to investigate the activity of thymol on Rhipicephalus microplus larvae under semi-natural conditions. For this purpose, tests were conducted in pots with Brachiaria decumbens seedlings containing cattle tick larvae. Thymol, diluted in ethanol 50° GL, was tested at concentrations of 2.5, 5.0, 10.0, 15.0, and 20.0 mg/mL, along with the control group treated with the solvent alone. Each treatment was composed of five pots (1 pot = a repetition). The experiment was performed in three steps. On the first day, the larvae were applied at the base of the signalgrass. Twenty-four hours later, approximately 25 mL of the solution was applied with thymol on the top of the vegetation in each pot. The survival of the larvae was measured 24 h after application of the solutions. Each pot was analyzed individually, and the grass fillets contained larvae were cut with scissors, placed in Petri dishes, and taken to the laboratory to count the number of living larvae. At the highest concentrations (10, 15, and 20 mg /mL), the number of live larvae declined by more than 95 % in relation to the control group. The lethal concentration 50 % (LC50) and LC90 values were 3.45 and 9.25 mg/ml, respectively. The application of thymol in semi-natural conditions starting concentration of 10 mg/mL significantly reduced the number of living R. microplus larvae.

Antibacterial activities of essential oils and extracts of Turkish Achillea, Satureja and Thymus species against plant pathogenic bacteria.

PubMed

Kotan, Recep; Cakir, Ahmet; Dadasoglu, Fatih; Aydin, Tuba; Cakmakci, Ramazan; Ozer, Hakan; Kordali, Saban; Mete, Ebru; Dikbas, Neslihan

2010-01-15

The aims of this study were to examine the chemical composition of the essential oils and hexane extracts of the aerial parts of Satureja spicigera (C. Koch) Boiss., Thymus fallax Fisch. & CA Mey, Achillea biebersteinii Afan, and Achillea millefolium L. by GC and GC-MS, and to test antibacterial efficacy of essential oils and n-hexane, chloroform, acetone and methanol extracts as an antibacterial and seed disinfectant against 25 agricultural plant pathogens. Thymol, carvacrol, p-cymene, thymol methyl ether and gamma-terpinene were the main constituents of S. spicigera and T. fallax oils and hexane extracts. The main components of the oil of Achillea millefolium were 1,8-cineole, delta-cadinol and caryophyllene oxide, whereas the hexane extract of this species contained mainly n-hexacosane, n-tricosane and n-heneicosane. The oils and hexane extracts of S. spicigera and T. fallax exhibited potent antibacterial activity over a broad spectrum against 25 phytopathogenic bacterial strains. Carvacrol and thymol, the major constituents of S. spicigera and T. fallax oils, also showed potent antibacterial effect against the bacteria tested. The oils of Achillea species showed weak antibacterial activity. Our results also revealed that the essential oil of S. spicigera, thymol and carvacrol could be used as potential disinfection agents against seed-borne bacteria. Our results demonstrate that S. spicigera, T. fallax oils, carvacrol and thymol could become potentials for controlling certain important agricultural plant pathogenic bacteria and seed disinfectant. Copyright (c) 2009 Society of Chemical Industry.

Evaluation of low copper content antifouling paints containing natural phenolic compounds as bioactive additives.

PubMed

Pérez, Miriam; García, Mónica; Blustein, Guillermo

2015-08-01

Cuprous oxide is the most commonly used biocide in antifouling paints. However, copper has harmful effects not only on the fouling community but also on non-target species. In the current study, we investigated the use of thymol, eugenol and guaiacol in this role combined with small quantities of copper. Phenolic compounds were tested for anti-settlement activity against cyprid larvae of the barnacle Balanus amphitrite and for their toxicity to nauplius larvae. Thymol, eugenol and guaiacol were active for anti-settlement but guaiacol had the disadvantage of being toxic to nauplius larvae. However, all of them showed therapeutic ratio>1. Antifouling paints with thymol (low copper content/thymol, LCP/T), eugenol (low copper content/eugenol, LCP/E) and guaiacol (low copper content/guaiacol, LCP/G) combined with small copper content were formulated for field trials. After 12 months exposure in the sea, statistical analysis revealed that LCP/T and LCP/E paints were the most effective combinations and had similar performances to control paints with high copper content (traditional cuprous oxide based paints). In contrast, LCP/G paint was only partially effective in preventing and inhibiting biofouling and was colonized by some hard and soft foulers. However, this antifouling paint was effective against calcareous tubeworm Hydroides elegans. In the light of various potential applications, thymol, eugenol and guaiacol have thus to be considered in future antifouling formulations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Supercritical CO2 impregnation of PLA/PCL films with natural substances for bacterial growth control in food packaging.

PubMed

Milovanovic, Stoja; Hollermann, Gesa; Errenst, Cornelia; Pajnik, Jelena; Frerich, Sulamith; Kroll, Stephen; Rezwan, Kurosch; Ivanovic, Jasna

2018-05-01

Biodegradable polymers with antibacterial properties are highly desirable materials for active food packaging applications. Thymol, a dietary monoterpene phenol with a strong antibacterial activity is abundant in plants belonging to the genus Thymus. This study presents two approaches for supercritical CO 2 impregnation of poly(lactic acid)(PLA)/poly(ε-caprolactone)(PCL) blended films to induce antibacterial properties of the material: (i) a batch impregnation process for loading pure thymol, and (ii) an integrated supercritical extraction-impregnation process for isolation of thyme extract and its incorporation into the films, operated in both batch or semi-continuous modes with supercritical solution circulation. The PCL content in films, impregnation time and CO 2 flow regime were varied to maximize loading of the films with thymol or thyme extract with preserving films' structure and thermal stability. Representative film samples impregnated with thymol and thyme extract were tested against Gram (-) (Escherichia coli) and Gram(+) (Bacillus subtilis) model strains, by measuring their metabolic activity and re-cultivation after exposure to the films. The film containing thymol (35.8 wt%) showed a strong antibacterial activity leading to a total reduction of bacterial cell viability. Proposed processes enable fast, controlled and organic solvent-free fabrication of the PLA/PCL films containing natural antibacterial substances at moderately low temperature, with a compact structure and a good thermal stability, for potential use as active food packaging materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

Toxic and repellent activity of selected monoterpenoids (thymol, carvacrol and linalool) against the castor bean tick, Ixodes ricinus (Acari: Ixodidae).

PubMed

Tabari, Mohaddeseh Abouhosseini; Youssefi, Mohammad Reza; Maggi, Filippo; Benelli, Giovanni

2017-10-15

The castor bean tick, Ixodes ricinus, is a species of medical and veterinary importance. The use of synthetic acaricides for tick control has led to development of resistance, residues in the environment and animal products, and public health concerns. In this regard, plant essential oils and their main constituents represent an appealing alternative strategy to combat ticks. The phenols thymol and carvacrol and the alcohol linalool are monoterpenoids occurring in essential oils of several aromatic and medicinal plants, such as thyme, oregano, savory, lavender and coriander. Recent studies have shown toxicity of these monoterpenoids against selected mosquito vectors and other arthropod pests. However, information on their bioactivity on I. ricinus is not available. On this basis, here we evaluated the ovicidal, larvicidal and repellency effects of these compounds against I. ricinus. Concentrations of 0.25, 0.5, 1, 2 and 5% were sprayed on the egg masses, then hatching rates were noted. Larvicidal assays were conducted on unengorged larvae, following the larval packet technique. The repellency was determined by measuring the vertical migration behavior of ticks in laboratory conditions. Carvacrol and thymol at all concentrations tested led to a significant hatching decrease, showing an efficacy higher than permethrin, whereas linalool did not cause any significant effect. In the larvae treated with carvacrol and thymol (1, 2 and 5%), mortality rates reached 100% after 24h, showing a larvicidal efficacy higher than permethrin, whereas no effect was seen in the larval groups treated with linalool. Carvacrol and thymol at all concentrations tested showed >90% repellency on I. ricinus. Linalool was scarcely effective (50.24% repellency) only at the concentration of 5%. Overall, based on these results, the phenols carvacrol and thymol can be considered as candidate ingredients for the development of novel acaricidal formulations to control the populations of I. ricinus and the spread of related tick-borne diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantification of urinary uric acid in the presence of thymol and thimerosal by high-performance liquid chromatography

NASA Technical Reports Server (NTRS)

Chen, Y.; Pietrzyk, R. A.; Whitson, P. A.

1997-01-01

A high-performance liquid chromatographic method was developed as an alternative to automated enzymatic analysis of uric acid in human urine preserved with thymol and/or thimerosal. Uric acid (tR = 10 min) and creatinine (tR = 5 min) were separated and quantified during isocratic elution (0.025 M acetate buffer, pH 4.5) from a mu Bondapak C18 column. The uric-acid peak was identified chemically by incubating urine samples with uricase. The thymol/thimerosal peak appeared at 31 min during the washing step and did not interfere with the analysis. We validated the high-performance liquid chromatographic method for linearity, precision and accuracy, and the results were found to be excellent.

Pharmacological Properties and Molecular Mechanisms of Thymol: Prospects for Its Therapeutic Potential and Pharmaceutical Development

PubMed Central

Nagoor Meeran, Mohamed Fizur; Javed, Hayate; Al Taee, Hasan; Azimullah, Sheikh; Ojha, Shreesh K.

2017-01-01

Thymol, chemically known as 2-isopropyl-5-methylphenol is a colorless crystalline monoterpene phenol. It is one of the most important dietary constituents in thyme species. For centuries, it has been used in traditional medicine and has been shown to possess various pharmacological properties including antioxidant, free radical scavenging, anti-inflammatory, analgesic, antispasmodic, antibacterial, antifungal, antiseptic and antitumor activities. The present article presents a detailed review of the scientific literature which reveals the pharmacological properties of thymol and its multiple therapeutic actions against various cardiovascular, neurological, rheumatological, gastrointestinal, metabolic and malignant diseases at both biochemical and molecular levels. The noteworthy effects of thymol are largely attributed to its anti-inflammatory (via inhibiting recruitment of cytokines and chemokines), antioxidant (via scavenging of free radicals, enhancing the endogenous enzymatic and non-enzymatic antioxidants and chelation of metal ions), antihyperlipidemic (via increasing the levels of high density lipoprotein cholesterol and decreasing the levels of low density lipoprotein cholesterol and low density lipoprotein cholesterol in the circulation and membrane stabilization) (via maintaining ionic homeostasis) effects. This review presents an overview of the current in vitro and in vivo data supporting thymol’s therapeutic activity and the challenges concerning its use for prevention and its therapeutic value as a dietary supplement or as a pharmacological agent or as an adjuvant along with current therapeutic agents for the treatment of various diseases. It is one of the potential candidates of natural origin that has shown promising therapeutic potential, pharmacological properties and molecular mechanisms as well as pharmacokinetic properties for the pharmaceutical development of thymol. PMID:28694777

[Treatment of cough in respiratory tract infections - the effect of combining the natural active compounds with thymol].

PubMed

Schönknecht, Karina; Krauss, Hanna; Jambor, Jerzy; Fal, Andrzej M

Cough is one of the characteristic symptoms of upper respiratory tract infections (URI). Herbal medicines are often used in the treatment of the cough associated with infection and to accelerate recovery or support the immune system. An example of such products are extracts of thyme and primrose, and also their combination with thymol. Thymus vulgaris is a spasmolytic, antimicrobial, anti-inflammatory, immunomodulatory and antioxidant agent. The most important component responsible for the activity of thyme is thymol contained in the volatile thyme oil. Primrose is, most of all, a saponine agent with expectorant and secretolytic activity, showing also spasmolytic, anti-inflammatory and antimicrobial effects. Because of the additive effects of the mentioned extracts and their wide activity profile they are often used as a combination drug. The use of this combination was assessed in the URI with the effects of alleviation of cough and dyspnea, and shortening the length of the disease. The effectiveness of the drug containing the extracts of thyme and primrose with the addition of thymol (Bronchosol®) was comparable to synthetic ambroxol and its safety has been proved. Moreover, the in-vitro antibacterial and antifungal effects of this drug have been evaluated.

Chemical composition and antimicrobial activity of Satureja hortensis and Trachyspermum copticum essential oil

PubMed Central

Mahboubi, M; Kazempour, N

2011-01-01

Background and Objectives The aim of this study was to evaluate the chemical composition and antimicrobial activity of Satureja hortensis and Trachyspermum copticum essential oils against different kinds of microorganisms in vitro. Material and Methods The antimicrobial activity was evaluated by micro broth dilution assay and the chemical composition of essential oils was analyzed by GC and GC/MS. Results Thymol, p-cymene, γ-terpinene and carvacrol were the main components of S. hortensis oil while thymol, γ-terpinene, and o-cymene were the major components of T. copticum oil. Two essential oils exhibited strong antimicrobial activity but the antimicrobial activity of T. copticum oil was higher than that of S. hortensis oil. Conclusion Thymol as a main component of oils plays an important role in antimicrobial activity. PMID:22530088

Synergism between carvacrol or thymol increases the antimicrobial efficacy of soy sauce with no sensory impact.

PubMed

Moon, Hyeree; Rhee, Min Suk

2016-01-18

Here, we examined the antimicrobial effects of soy sauce containing essential oils (EOs) against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes at 22°C and 4°C. To screen a variety of combined effects, soy sauce was mixed with six different EOs (carvacrol, thymol, eugenol, trans-cinnamaldehyde, β-resorcylic acid, and vanillin), each at a concentration of 1mM for 10 min. None of the oils showed bactericidal activity when used alone. Soy sauce combined with carvacrol and thymol induced the greatest antibacterial activity against all tested bacteria; therefore, these oils were further tested at 0.25, 0.5, and 1mM (0.0039%, 0.0078%, and 0.0157%) for 1, 5, and 10 min at 4°C and 22°C. In addition, sensory evaluation of soy sauce containing each EO at 0.25, 0.5, 1, and 2mM was performed using the nine point hedonic test. Carvacrol or thymol (1mM) eliminated all the test bacteria (initial population, 7.0-7.5logCFU/ml) in 1-5 min at 22°C and within 10 min at 4°C. L. monocytogenes was slightly more tolerant at 4°C, which may be attributable to the ability of the cell membrane to adapt to low temperatures. The sensory scores for soy sauce containing EOs were not significantly different from that of soy sauce without EOs (P>0.05). The stability of EO efficacy in soy sauce was also verified. These results suggest that carvacrol and thymol act synergistically with other factors present in soy sauce to increase antimicrobial activity against major foodborne pathogens at both 4°C and 22°C. The synergism may be attributable to the combination of factors (mainly high salt concentration and low pH imparted by organic acids) present in soy sauce and the membrane attacking properties of carvacrol and thymol. This method will facilitate the production of microbiologically safe soy sauce, soy sauce-based marinades, and various marinated foods. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of thymol and carvacrol on nutrient digestibility in rams fed high or low concentrate diets.

PubMed

Zamiri, M J; Azizabadi, E; Momeni, Z; Rezvani, M R; Atashi, H; Akhlaghi, A

2015-01-01

Published data on the effects of essential oils (EO) on in vivo nutrient digestibility in sheep are contradictory. In 2 experiments, the effect of thymol and carvacrol on nutrient digestibility was studied in sheep fed with high (70%) or low (52%) concentrate diets, using incomplete Latin Square designs. The essential oils were mixed with the concentrate portion of the diet at the rate of 0.0, 0.3, or 0.6 g per kg dry matter (DM) diet. Supplementation of thymol had no significant effect on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and acid detergent fiber (ADF). The main effect of thymol on neutral detergent fiber (NDF) and ether extract (EE) digestibility and on nitrogen balance (NB) was significant (P<0.05), but within each level of dietary concentrate no significant differences were observed for these measurements. Overall, ruminal ammonia concentration was higher (P<0.05) in both HCD and LCD lambs receiving 0.3 mg thymol per kg diet. Supplementation of carvacrol had no significant effect on nutrient digestibility. The main effect of carvacrol on ruminal ammonia levels and NB was significant, but within each level of dietary concentrate no significant differences were observed in ammonia levels and NB. Inclusion of 0.3 g/kg diet DM of carvacrol or thyme was more effective than 0.6 g/kg diet DM in terms of NB but neither dose affected nutrient digestibility. Future research should determine the long-term effects of essential oils on digestibility and performance in sheep, before recommendation can be made for their use under practical husbandry conditions.

Essential oils have different effects on human pathogenic and commensal bacteria in mixed faecal fermentations compared with pure cultures.

PubMed

Thapa, Dinesh; Louis, Petra; Losa, Riccardo; Zweifel, Béatrice; Wallace, R John

2015-02-01

A static batch culture system inoculated with human faeces was used to determine the influence of essential oil compounds (EOCs) on mixed faecal microbiota. Bacteria were quantified using quantitative PCR of 16S rRNA genes. Incubation for 24 h of diluted faeces from six individuals caused enrichment of Bifidobacterium spp., but proportions of other major groups were unaffected. Thymol and geraniol at 500 p.p.m. suppressed total bacteria, resulting in minimal fermentation. Thymol at 100 p.p.m. had no effect, nor did eugenol or nerolidol at 100 or 500 p.p.m. except for a slight suppression of Eubacterium hallii. Methyl isoeugenol at 100 or 500 p.p.m. suppressed the growth of total bacteria, accompanied by a large fall in the molar proportion of propionate formed. The relative abundance of Faecalibacterium prausnitzii was unaffected except with thymol at 500 p.p.m. The ability of EOCs to control numbers of the pathogen Clostridium difficile was investigated in a separate experiment, in which the faecal suspensions were amended by the addition of pure culture of C. difficile. Numbers of C. difficile were suppressed by thymol and methyl isoeugenol at 500 p.p.m. and to a lesser extent at 100 p.p.m. Eugenol and geraniol gave rather similar suppression of C. difficile numbers at both 100 and 500 p.p.m. Nerolidol had no significant effect. It was concluded from these and previous pure-culture experiments that thymol and geraniol at around 100 p.p.m. could be effective in suppressing pathogens in the small intestine, with no concern for beneficial commensal colonic bacteria in the distal gut. © 2015 The Authors.

Toxicological properties of thio- and alkylphenols causing flavor tainting in fish from the upper Wisconsin River

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heil, T.P.; Lindsay, R.C.

1989-08-01

EC50 Microtox (5 min, 25 degrees C) assay values for 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, 2,4-diisopropylphenol, 2,5-diisopropylphenol 2,6-diisopropylphenol, 3,5-diisopropylphenol, carvacrol, thymol, thiophenol, and thiocresol ranged from 2 x 10(-2) mM for thymol (least toxic) to 2 x 10(-4) mM for 2,4-diisopropylphenol and 4-isopropylphenol (most toxic).

Antifungal, phytotoxic and insecticidal properties of essential oil isolated from Turkish Origanum acutidens and its three components, carvacrol, thymol and p-cymene.

PubMed

Kordali, Saban; Cakir, Ahmet; Ozer, Hakan; Cakmakci, Ramazan; Kesdek, Memis; Mete, Ebru

2008-12-01

The chemical composition of essential oil isolated by hydrodistillation from the aerial parts of Origanum acutidens was analyzed by GC-MS. Carvacrol (87.0%), p-cymene (2.0%), linalool acetate (1.7%), borneol (1.6%) and beta-caryophyllene (1.3%) were found to be as main constituents. Antifungal, phytotoxic and insecticidal activities of the oil and its aromatic monoterpene constituents, carvacrol, p-cymene and thymol were also determined. The antifungal assays showed that O. acutidens oil, carvacrol and thymol completely inhibited mycelial growth of 17 phytopathogenic fungi and their antifungal effects were higher than commercial fungicide, benomyl. However, p-cymene possessed lower antifungal activity. The oil, carvacrol and thymol completely inhibited the seed germination and seedling growth of Amaranthus retroflexus, Chenopodium album and Rumex crispus and also showed a potent phytotoxic effect against these plants. However, p-cymene did not show any phytotoxic effect. Furthermore, O. acutidens oil showed 68.3% and 36.7% mortality against Sitophilus granarius and Tribolium confusum adults, respectively. The findings of the present study suggest that antifungal and herbicidal properties of the oil can be attributed to its major component, carvacrol, and these agents have a potential to be used as fungicide, herbicide as well as insecticide.

Combined effect of carnosol, rosmarinic acid and thymol on the oxidative stability of soybean oil using a simplex centroid mixture design.

PubMed

Saoudi, Salma; Chammem, Nadia; Sifaoui, Ines; Jiménez, Ignacio A; Lorenzo-Morales, Jacob; Piñero, José E; Bouassida-Beji, Maha; Hamdi, Moktar; L Bazzocchi, Isabel

2017-08-01

Oxidation taking place during the use of oil leads to the deterioration of both nutritional and sensorial qualities. Natural antioxidants from herbs and plants are rich in phenolic compounds and could therefore be more efficient than synthetic ones in preventing lipid oxidation reactions. This study was aimed at the valorization of Tunisian aromatic plants and their active compounds as new sources of natural antioxidant preventing oil oxidation. Carnosol, rosmarinic acid and thymol were isolated from Rosmarinus officinalis and Thymus capitatus by column chromatography and were analyzed by nuclear magnetic resonance. Their antioxidant activities were measured by DPPH, ABTS and FRAP assays. These active compounds were added to soybean oil in different proportions using a simplex-centroid mixture design. Antioxidant activity and oxidative stability of oils were determined before and after 20 days of accelerated oxidation at 60 °C. Results showed that bioactive compounds are effective in maintaining oxidative stability of soybean oil. However, the binary interaction of rosmarinic acid and thymol caused a reduction in antioxidant activity and oxidative stability of soybean oil. Optimum conditions for maximum antioxidant activity and oxidative stability were found to be an equal ternary mixture of carnosol, rosmarinic acid and thymol. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Phytotoxicity and Cytotoxicity of Essential Oil from Leaves of Plectranthus amboinicus, Carvacrol, and Thymol in Plant Bioassays.

PubMed

Pinheiro, Patrícia Fontes; Costa, Adilson Vidal; Alves, Thammyres de Assis; Galter, Iasmini Nicoli; Pinheiro, Carlos Alexandre; Pereira, Alexandre Fontes; Oliveira, Carlos Magno Ramos; Fontes, Milene Miranda Praça

2015-10-21

The essential oil of Plectranthus amboinicus and its chemotypes, carvacrol and thymol, were evaluated on the germination and root and aerial growth of Lactuca sativa and Sorghum bicolor and in acting on the cell cycle of meristematic root cells of L. sativa. The main component found in the oil by analysis in gas chromatography-mass spectrometry and gas chromatography flame ionization detection was carvacrol (88.61% in area). At a concentration of 0.120% (w v(-1)), the oil and its chemotypes retarded or inhibited the germination and decreased root and aerial growth in monocot and dicot species used in the bioassays. In addition, all substances caused changes in the cell cycle of the meristematic cells of L. sativa, with chromosomal alterations occurring from the 0.015% (w v(-1)) concentration. The essential oil of P. amboinicus, carvacrol, and thymol have potential for use as bioherbicides.

Chemical composition of the Lippia origanoides essential oils and their antigenotoxicity against bleomycin-induced DNA damage.

PubMed

Vicuña, Gloria Carolina; Stashenko, Elena E; Fuentes, Jorge Luis

2010-07-01

The present work evaluated the chemical composition of the essential oils (EO) obtained from Lippia origanoides and their DNA protective effect against bleomycin-induced genotoxicity. L. origanoides EO chemical composition was determined by gas chromatography-mass spectrometry (GC-MS). The major compounds of the L. origanoides EOs were thymol (34-58%) and carvacrol (26%). The antigenotoxic effects of the EOs, major compounds and standard compound (epigallocatechin gallate) were assayed in co-incubation procedures using the SOS chromotest in Escherichia coli. Both EOs and their major compounds protected bacterial cells against bleomycin-induced genotoxicity indicating that these two compounds were principally responsible for the antigenotoxicity detected in the oils. Thymol and carvacrol antigenotoxicity was lower than those observed with epigallocatechin gallate. The results were discussed in relation to the chemopreventive potential of L. origanoides EOs and their major components, carvacrol and thymol. Copyright 2009 Elsevier B.V. All rights reserved.

Antifungal activity against Candida albicans of starch Pickering emulsion with thymol or amphotericin B in suspension and calcium alginate films.

PubMed

Cossu, Andrea; Wang, Min S; Chaudhari, Amol; Nitin, Nitin

2015-09-30

Conventional antifungal treatments against Candida albicans in the oral cavity often result in increased cytotoxicity. The goal of this study was to determine the potential of starch Pickering emulsion as a delivery vehicle for an antifungal natural phenolic compound such as thymol in simulated saliva fluid (SSF) compared to amphotericin B. An oil-in-water (o/w) emulsion was stabilized using starch particles. Physical stability of the emulsion and disruption induced by α-amylase activity in SSF was evaluated. Encapsulated thymol in o/w emulsion was compared to encapsulated amphotericin B for antifungal activity against C. albicans in suspension using emulsions or zone inhibition assay on agar plates using emulsions dispersed in alginate films. Results showed that the emulsions were stable for at least three weeks. Digestion of the emulsion by α-amylase led to coalescence of emulsion droplets. The antifungal activity of thymol and amphotericin B in emulsion formulation was enhanced upon incubation with α-amylase. Results from the zone inhibition assay demonstrated efficacy of the emulsions dispersed in alginate films. Interestingly, addition of α-amylase to the alginate films resulted in a decreased inhibitory effect. Overall, this study showed that starch Pickering emulsions have a potential to deliver hydrophobic antifungal compounds to treat oral candidiasis. Copyright © 2015 Elsevier B.V. All rights reserved.

Cell viability of Candida albicans against the antifungal activity of thymol.

PubMed

de Vasconcelos, Laís César; Sampaio, Fabio Correia; Albuquerque, Allan de Jesus dos Reis; Vasconcelos, Laurylene César de Souza

2014-01-01

Candida albicans is a commensal fungus, but circumstantially it may cause superficial infections of the mucous membranes, such as denture stomatitis, when a biofilm is formed on the surface of dental prostheses. This study evaluated the cell viability of C. albicans biofilms against the antifungal activity of thymol when compared with miconazole, by the fluorescence imaging using SYTO 9 and propidium iodide dyes, and counting of colony forming units. C. albicans standard strains (ATCC 11006) were used. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of drugs were determined by broth microdilution tests and the inoculum was standardized to match 0.5 on the McFarland scale (106 cfu/mL). Biofilms were grown on the surface of acrylic resin disks in parallel flow chambers from Sabouraud broth supplemented with 10% dextrose. For counting of colony forming units, the fungal solution was sequentially diluted and plated in Sabouraud dextrose agar. Data were analyzed using two-way ANOVA and Tukey's test (a=5%). Biofilms treated with thymol and miconazole presented low numbers of viable cells at the evaluated exposure times. There was statistically significant difference (p<0.05) when compared with control, and the mean value of the exposure times between miconazole and thymol did not differ significantly (p>0.05). In conclusion, both drugs have similar efficiency as antifungal agents against biofilms of C. albicans formed on acrylic surfaces.

Antigenotoxic Effect Against Ultraviolet Radiation-induced DNA Damage of the Essential Oils from Lippia Species.

PubMed

Quintero Ruiz, Nathalia; Córdoba Campo, Yuri; Stashenko, Elena E; Fuentes, Jorge Luis

2017-07-01

The antigenotoxicity against ultraviolet radiation (UV)-induced DNA damage of essential oils (EO) from Lippia species was studied using SOS Chromotest. Based on the minimum concentration that significantly inhibits genotoxicity, the genoprotective potential of EO from highest to lowest was Lippia graveolens, thymol-RC ≈ Lippia origanoides, carvacrol-RC ≈ L. origanoides, thymol-RC > Lippia alba, citral-RC ≈ Lippia citriodora, citral-RC ≈ Lippia micromera, thymol-RC > L. alba, myrcenone-RC. EO from L. alba, carvone/limonene-RC, L. origanoides, α-phellandrene-RC and L. dulcis, trans-β-caryophyllene-RC did not reduce the UV genotoxicity at any of the doses tested. A gas chromatography with flame ionization detection analysis (GC-FID) was conducted to evaluate the solubility of the major EO constituents under our experimental conditions. GC-FID analysis showed that, at least partially, major EO constituents were water-soluble and therefore, they were related with the antigenotoxicity detected for EO. Constituents such as p-cymene, geraniol, carvacrol, thymol, citral and 1,8-cineole showed antigenotoxicity. The antioxidant activity of EO constituents was also determined using the oxygen radical antioxidant capacity (ORAC) assay. The results showed that the antigenotoxicity of the EO constituents was unconnected with their antioxidant activity. The antigenotoxicity to different constituent binary mixtures suggests that synergistic effects can occur in some of the studied EO. © 2017 The American Society of Photobiology.

Effect of storage duration/solution on microshear bond strength of composite to enamel.

PubMed

Tosun, Gul; Sener, Yagmur; Sengun, Abdulkadir

2007-01-01

The aim of this study was to determine the effect of three storage solutions and two storage durations on microshear bond strength (microSBS) of a resin composite. Sixty non-carious human permanent molars were stored in three storage solutions (0.1% thymol, 10% formalin, and distilled water). Each tooth was separated mesio-distally into two parts. Specimens of the first part were stored for 24 hours, while specimens of the second part were stored for two months in the solutions. After each storage period, the enamel surface was covered with a composite resin in combination with an etch-rinse adhesive system. Specimens were then serially sectioned into sticks of 1 mm' bond area and subjected to microSBS test. There were no statistically significant differences between the two storage periods for each solution (p>0.05). The thymol solution group showed lower microSBS values than those of distilled water for both storage periods (p<0.05). As for the formalin group, its microSBS values were not statistically different from those of distilled water and thymol groups at each storage period (p>0.05). In conclusion, the thymol solution caused the microSBS of the resin composite to decrease when compared to both formalin and distilled water after 24 hours and two months. However, the microSBS of the resin composite was not affected by storage duration.

Antioxidant Activity of the Essential Oil and its Major Terpenes of Satureja macrostema (Moc. and Sessé ex Benth.) Briq.

PubMed

Torres-Martínez, Rafael; García-Rodríguez, Yolanda Magdalena; Ríos-Chávez, Patricia; Saavedra-Molina, Alfredo; López-Meza, Joel Edmundo; Ochoa-Zarzosa, Alejandra; Garciglia, Rafael Salgado

2018-01-01

The aim of this study was to investigate the in vitro antioxidant activity of Satureja macrostema (Moc. and Sessé ex Benth.) Briq. (Lamiaceae) essential oil, a Mexican medicinal plant known as nurite. Fresh aerial parts of S. macrostema plants cultivated in greenhouse for 3 months were subjected to hydrodistillation in a Clevenger apparatus to obtain essential oil. Volatile compounds were identified by gas chromatography (GC) and GC/mass spectrometry. Antioxidant effectiveness of essential oil and its major terpenes of S. macrostema was examined by three different radical scavenging methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and total antioxidant capacity (TAC). The concentrations tested were 0.001, 0.01, 0.1, and 1 mg/mL. The major volatile compounds were caryophyllene, limonene, linalool, pulegone, menthone, and thymol. S. macrostema essential oil showed the highest free radical scavenging activity with DPPH and ABTS methods (53.10% and 92.12%, respectively) at 1 mg/mL and 98% with TAC method at 0.1 mg/mL. Thymol exerted the highest antioxidant capacity with 0.1 mg/mL, reaching 83.38%, 96.96%, and 98.57% by DPPH, ABTS, and TAC methods. Caryophyllene, limonene, linalool, pulegone, and menthone exhibited an antioxidant capacity <25% with the DPPH and ABTS methods; however, limonene showed a TAC of 85.41% with 0.01 mg/mL. The essential oil of S. macrostema and thymol showed a free radical scavenging activity close to that of the synthetic butylated hydroxytoluene. The major volatile compounds of essential oil of Satureja macrostema were caryophyllene, limonene, linalool, pulegone, menthone and thymolThe essential oil of S. macrostema showed a high free radical scavengingThymol exerted the highest antioxidant capacity by DPPH, ABTS and TAC methods. Abbreviations used: GC: Gas Chromatography; DPPH: 2,2-diphenyl-1-picrylhydrazyl; ABTS: 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid; TAC: Total antioxidant capacity.

Modeling the Inactivation of Intestinal Pathogenic Escherichia coli O157:H7 and Uropathogenic E. coli in Ground Chicken by High Pressure Processing and Thymol

PubMed Central

Chien, Shih-Yung; Sheen, Shiowshuh; Sommers, Christopher H.; Sheen, Lee-Yan

2016-01-01

Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compared the resistance of iPEC (O157:H7) to UPEC in chicken meat using High Pressure Processing (HPP) in with (the hurdle concept) and without thymol essential oil as a sensitizer. UPEC was found slightly more resistant than E. coli O157:H7 (iPEC O157:H7) at 450 and 500 MPa. A central composite experimental design was used to evaluate the effect of pressure (300–400 MPa), thymol concentration (100–200 ppm), and pressure-holding time (10–20 min) on the inactivation of iPEC O157:H7 and UPEC in ground chicken. The hurdle approach reduced the high pressure levels and thymol doses imposed on the food matrices and potentially decreased food quality damaged after treatment. The quadratic equations were developed to predict the impact (lethality) on iPEC O157:H7 (R2 = 0.94) and UPEC (R2 = 0.98), as well as dimensionless non-linear models [Pr > F (<0.0001)]. Both linear and non-linear models were validated with data obtained from separated experiment points. All models may predict the inactivation/lethality within the same order of accuracy. However, the dimensionless non-linear models showed potential applications with parameters outside the central composite design ranges. The results provide useful information of both iPEC O157:H7 and UPEC in regard to how they may survive HPP in the presence or absence of thymol. The models may further assist regulatory agencies and food industry to assess the potential risk of iPEC O157:H7 and UPEC in ground chicken. PMID:27379050

Evaluation of the Antibacterial Potential of Liquid and Vapor Phase Phenolic Essential Oil Compounds against Oral Microorganisms

PubMed Central

Wu, Chi-Hao; Ko, Shun-Yao; Chen, Michael Yuanchien; Shih, Yin-Hua; Shieh, Tzong-Ming; Chuang, Li-Chuan; Wu, Ching-Yi

2016-01-01

The aim of the present study was to determine the antibacterial activities of the phenolic essential oil (EO) compounds hinokitiol, carvacrol, thymol, and menthol against oral pathogens. Aggregatibacter actinomycetemcomitans, Streptococcus mutans, Methicillin-resistant Staphylococcus aureus (MRSA), and Escherichia. coli were used in this study. The minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), bacterial growth curves, temperature and pH stabilities, and synergistic effects of the liquid and vapor EO compounds were tested. The MIC/MBC of the EO compounds, ranging from the strongest to weakest, were hinokitiol (40–60 μg/mL/40-100 μg/mL), thymol (100–200 μg/mL/200-400 μg/mL), carvacrol (200–400 μg/mL/200-600 μg/mL), and menthol (500-more than 2500 μg/mL/1000-more than 2500 μg/mL). The antibacterial activities of the four EO phenolic compound based on the agar diffusion test and bacterial growth curves showed that the four EO phenolic compounds were stable under different temperatures for 24 h, but the thymol activity decreased when the temperature was higher than 80°C. The combination of liquid carvacrol with thymol did not show any synergistic effects. The activities of the vaporous carvacrol and thymol were inhibited by the presence of water. Continual violent shaking during culture enhanced the activity of menthol. Both liquid and vaporous hinokitiol were stable at different temperatures and pH conditions. The combination of vaporous hinokitiol with zinc oxide did not show synergistic effects. These results showed that the liquid and vapor phases of hinokitiol have strong anti-oral bacteria abilities. Hinokitiol has the potential to be applied in oral health care products, dental materials, and infection controls to exert antimicrobial activity. PMID:27681039

Characterization of Thymol blue Radiochromic dosimeters for high dose applications

NASA Astrophysics Data System (ADS)

Aldweri, Feras M.; Abuzayed, Manar H.; Al-Ajaleen, Musab S.; Rabaeh, Khalid A.

2018-03-01

Thymol blue (TB) solutions and Thymol blue Polyvinyl Alcohol (TB-PVA) films have been introduced as Radiochromic dosimeter for high dose applications. The dosimeters were irradiated with gamma ray (60Co source) from 5 to 30 kGy for film, and from 0.150 kGy to 4 kGy for solution. The optical density of unirradiated and irradiated TB solution as well as TB-PVA film dosimeters were studied in terms of absorbance at 434 nm using UV/VIS spectrophotometer. The effects of scan temperature, light pre-gamma irradiation, dose rate, relative humidity and stability of the absorbance of solutions and films after irradiation were investigated. We found the dose sensitivity of TB solution and TB-PVA film dosimeters increases significantly with increases of the absorbed dose as well as with the increases of TB dye concentrations. The useful dose range of developed TB solutions and TB-PVA films dosimeters is in the range 0.125-1 kGy and of 5-20 kGy, respectively.

Trachyspermum ammi (L.) sprague: chemical composition of essential oil and antimicrobial activities of respective fractions.

PubMed

Moein, Mahmoodreza R; Zomorodian, Kamiar; Pakshir, Keyvan; Yavari, Farnoosh; Motamedi, Marjan; Zarshenas, Mohammad M

2015-01-01

Resistance to antibacterial agents has become a serious problem for global health. The current study evaluated the antimicrobial activities of essential oil and respective fractions of Trachyspermum ammi (L.) Sprague. Seeds of the essential oil were extracted and fractionated using column chromatography. All fractions were then analyzed by gas chromatography/mass spectrometry. Antifungal and antibacterial activities of the oil and its fractions were assessed using microdilution method. Compounds γ-terpinene (48.07%), ρ-cymene (33.73%), and thymol (17.41%) were determined as major constituents. The effect of fraction II was better than total essential oil, fraction I, and standard thymol. The greater effect of fraction II compared to standard thymol showed the synergistic effects of the ingredients in this fraction. As this fraction and also total oil were effective on the studied microorganism, the combination of these products with current antimicrobial agents could be considered as new antimicrobial compounds in further investigations. © The Author(s) 2014.

Antimicrobial effects of essential oils in combination with chlorhexidine digluconate.

PubMed

Filoche, S K; Soma, K; Sissons, C H

2005-08-01

The aim of the present study was to compare antimicrobial effects of essential oils alone and in combination with chlorhexidine digluconate against planktonic and biofilm cultures of Streptococcus mutans and Lactobacillus plantarum. The essential oils included cinnamon, tea-tree (Melaleuca alternifola), manuka (Leptospermum scoparium), Leptospermum morrisonii, arnica, eucalyptus, grapefruit, the essential oil mouthrinse Cool Mint Listerine and two of its components, menthol and thymol. Cinnamon exhibited the greatest antimicrobial potency (1.25-2.5 mg/ml). Manuka, L. morrisonii, tea-tree oils, and thymol also showed antimicrobial potency but to a lesser extent. The combination effect of the essential oil-chlorhexidine was greater against biofilm cultures of both S. mutans and L. plantarum than against planktonic cultures. The amount of chlorhexidine required to achieve an equivalent growth inhibition against the biofilm cultures was reduced 4-10-fold in combination with cinnamon, manuka, L. morrisonii, thymol, and Listerine. We conclude that there may be a role for essential oils in the development of novel anticaries treatments.

Alkylphenol Activity against Candida spp. and Microsporum canis: A Focus on the Antifungal Activity of Thymol, Eugenol and O-Methyl Derivatives.

PubMed

Fontenelle, Raquel O S; Morais, Selene M; Brito, Erika H S; Brilhante, Raimunda S N; Cordeiro, Rossana A; Lima, Ynayara C; Brasil, Nilce V G P S; Monteiro, André J; Sidrim, José J C; Rocha, Marcos F G

2011-07-29

In recent years there has been an increasing search for new antifungal compounds due to the side effects of conventional antifungal drugs and fungal resistance. The aims of this study were to test in vitro the activity of thymol, eugenol, estragole and anethole and some O-methyl-derivatives (methylthymol and methyleugenol) against Candida spp. and Microsporum canis. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC). The minimum fungicidal concentrations (MFC) for both Candida spp. and M. canis were found by subculturing each fungal suspension on potato dextrose agar. Thymol, methylthymol, eugenol, methyl-eugenol, anethole, estragole and griseofulvin respectively, presented the following MIC values against M. canis: 4.8-9.7; 78-150; 39; 78-150; 78-150; 19-39 µg/mL and 0.006-2.5 mg/mL. The MFC values for all compounds ranged from 9.7 to 31 µg/mL. Concerning Candida spp, thymol, methylthymol, eugenol, methyleugenol, anethole, estragole and amphotericin, respectively, showed the following MIC values: 39; 620-1250; 150-620; 310-620; 620; 620-1250 and 0.25-2.0 mg/mL. The MFC values varied from 78 to 2500 µg/mL. All tested compounds thus showed in vitro antifungal activity against Candida spp. and M. canis. Therefore, further studies should be carried out to confirm the usefulness of these alkylphenols in vivo.

Antioxidant Activity of the Essential Oil and its Major Terpenes of Satureja macrostema (Moc. and Sessé ex Benth.) Briq.

PubMed Central

Torres-Martínez, Rafael; García-Rodríguez, Yolanda Magdalena; Ríos-Chávez, Patricia; Saavedra-Molina, Alfredo; López-Meza, Joel Edmundo; Ochoa-Zarzosa, Alejandra; Garciglia, Rafael Salgado

2017-01-01

Background: The aim of this study was to investigate the in vitro antioxidant activity of Satureja macrostema (Moc. and Sessé ex Benth.) Briq. (Lamiaceae) essential oil, a Mexican medicinal plant known as nurite. Materials and Methods: Fresh aerial parts of S. macrostema plants cultivated in greenhouse for 3 months were subjected to hydrodistillation in a Clevenger apparatus to obtain essential oil. Volatile compounds were identified by gas chromatography (GC) and GC/mass spectrometry. Antioxidant effectiveness of essential oil and its major terpenes of S. macrostema was examined by three different radical scavenging methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and total antioxidant capacity (TAC). The concentrations tested were 0.001, 0.01, 0.1, and 1 mg/mL. Results: The major volatile compounds were caryophyllene, limonene, linalool, pulegone, menthone, and thymol. S. macrostema essential oil showed the highest free radical scavenging activity with DPPH and ABTS methods (53.10% and 92.12%, respectively) at 1 mg/mL and 98% with TAC method at 0.1 mg/mL. Thymol exerted the highest antioxidant capacity with 0.1 mg/mL, reaching 83.38%, 96.96%, and 98.57% by DPPH, ABTS, and TAC methods. Caryophyllene, limonene, linalool, pulegone, and menthone exhibited an antioxidant capacity <25% with the DPPH and ABTS methods; however, limonene showed a TAC of 85.41% with 0.01 mg/mL. Conclusion: The essential oil of S. macrostema and thymol showed a free radical scavenging activity close to that of the synthetic butylated hydroxytoluene. SUMMARY The major volatile compounds of essential oil of Satureja macrostema were caryophyllene, limonene, linalool, pulegone, menthone and thymolThe essential oil of S. macrostema showed a high free radical scavengingThymol exerted the highest antioxidant capacity by DPPH, ABTS and TAC methods. Abbreviations used: GC: Gas Chromatography; DPPH: 2,2-diphenyl-1-picrylhydrazyl; ABTS: 2,2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid; TAC: Total antioxidant capacity. PMID:29491647

Evaluation of essential oils in beef cattle manure slurries and applications of select compounds to beef feedlot surfaces to control zoonotic pathogens.

PubMed

Wells, J E; Berry, E D; Guerini, M N; Varel, V H

2015-02-01

To evaluate natural terpene compounds for antimicrobial activities and determine whether these compounds could be used to control microbial activities and pathogens in production animal facilities. Thymol, geraniol, glydox, linalool, pine oil, plinol and terpineol were tested in laboratory studies for ability to control the production of odorous volatile fatty acid compounds and reduce pathogen levels in manure slurry preparations. Thymol is a terpene phenolic compound and was most effective for reducing fermentation products and pathogen levels (P < 0.05), followed by the extracts linalool, pine oil and terpineol, which are terpene alcohols. Select compounds thymol, linalool and pine oil were further evaluated in two separate studies by applying the agents to feedlot surfaces in cattle pens. Feedlot surface material (FSM; manure and soil) was collected and analysed for fermentation products, levels of coliforms and total Escherichia coli, and the presence of E. coli O157:H7, Campylobacter, Salmonella, Listeria and L. monocytogenes. The reduction in fermentation products but not pathogens was dependent on the moisture present in the FSM. Treatment with 2000 ppm thymol reduced the prevalence of E. coli O157:H7 but not Listeria. In a separate study, treatment with 4000 ppm pine oil reduced E. coli O157:H7, Listeria and Campylobacter (P < 0.05). Linalool was tested at two levels (2000 and 4000 ppm) and did not affect pathogen levels at either concentration. Natural compounds bearing terpenes can control pathogenic bacteria in treated manures and when applied to the feedlot surface in production cattle systems. Pine oil is a cheaper alternative to thymol and may be a useful treatment for controlling pathogens. The control of bacterial pathogens in animal productions systems is an important step in preharvest food safety. Waste products, such as pine oil extract, from the pulp wood industry may have application for treating feedlot pens and manures to reduce the pathogen load. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Thymus vulgaris L. and thymol assist murine macrophages (RAW 264.7) in the control of in vitro infections by Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans.

PubMed

de Oliveira, Jonatas Rafael; Figueira, Leandro Wagner; Sper, Fábia Lugli; Meccatti, Vanessa Marques; Camargo, Samira Esteves Afonso; de Oliveira, Luciane Dias

2017-08-01

Microorganisms are capable to combat defense cells by means of strategies that contribute to their stabilization and proliferation in invaded tissues. Frequently antimicrobial-resistant strains appear; therefore, alternative methods to control them must be investigated, for example, the use of plant products. The capacity of the thyme extract (Thymus vulgaris L.) and phytocompound thymol in the control of in vitro infections by Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans in murine macrophages (RAW 264.7) was evaluated. Minimal inhibitory concentrations (MIC) of the plant products were used. The effect of these MIC were analyzed in the assays of phagocytosis and immunoregulation by analysis of the production of cytokines (IL-1β, TNF-α, and IL-10) and nitric oxide (NO). The plant products effectively assisted the macrophages in the phagocytosis of microorganisms, presenting significant reductions of S. aureus and P. aeruginosa. The macrophages also regulated the production of inflammatory mediators in the infections by S. aureus, P. aeruginosa, and C. albicans. In addition, thyme provided a satisfactory effect in response to the bacterial infections, regarding generation of NO. Thus, the effectiveness of the thyme and thymol to control in vitro infections by S. aureus, P. aeruginosa, and C. albicans was observed. Phagocytosis of S. aureus by RAW 264.7 was enhanced with thymol Thyme enhanced the phagocytosis of P. aeruginosa by RAW 264.7 Plant products provided immunoregulation of inflammatory cytokines Production of nitric oxide was improved with the treatments in bacterial infections.

Application of Optimized Vortex-Assisted Surfactant-Enhanced DLLME for Preconcentration of Thymol and Carvacrol, and Their Determination by HPLC-UV: Response Surface Methodology.

PubMed

Ghaedi, Mehrorang; Roosta, Mostafa; Khodadoust, Saeid; Daneshfar, Ali

2015-08-01

A novel vortex-assisted surfactant-enhanced dispersive liquid-liquid microextraction combined with high-performance liquid chromatography (VASEDLLME-HPLC) was developed for the determination of thymol and carvacrol (phenolic compound). In this method, the extraction solvent (CHCl3) was dispersed into the aqueous samples via a vortex agitator and addition of the surfactant (Triton X-100). The preliminary experiments were undertaken to select the best extraction solvent and surfactant. The influences of effective variables were investigated using a Plackett-Burman 2(7-4) screening design and then, the significant variables were optimized by using a central composite design combined with desirability function. Working under optimum conditions specified as: 140 µL CHCl3, 0.08% (w/v, Triton X-100), 3 min extraction time, 6 min centrifugation at 4,500 rpm, pH 7, 0.0% (w/v) NaCl permit achievement of high and reasonable linear range over 0.005-4.0 mg L(-1) with R(2) = 0.9998 (n = 10). The separation of thymol and carvacrol was achieved in <14 min using a C18 column and an isocratic binary mobile phase acetonitrile-water (55:45, v/v) with a flow rate of 1.0 mL min(-1). The VASEDLLME is applied for successful determination of carvacrol and thymol in different thyme and pharmaceutical samples with relative standard deviation <4.7% (n = 5). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Development and evaluation of thymol-chitosan hydrogels with antimicrobial-antioxidant activity for oral local delivery.

PubMed

Alvarez Echazú, María Inés; Olivetti, Christian Ezequiel; Anesini, Claudia; Perez, Claudio Javier; Alvarez, Gisela Solange; Desimone, Martin Federico

2017-12-01

Nowadays, the research of innovative drug delivery devices is focused on the design of multiple drug delivery systems, the prevention of drug side effects and the reduction of dosing intervals. Particularly, new mucosal delivery systems for antimicrobials, antioxidants and anti-inflammatory drugs has a growing development, regards to the avoidance of side effects, easy administration and a suitable drug concentration in the mucosa. In this work, chitosan hydrogels are evaluated as a biodegradable scaffold and as a bioactive agent carrier of an antioxidant-antimicrobial compound called thymol. Throughout the study, swelling behavior, viscoelastic properties and thermal analysis are highlighted to present its advantages for a biomedical application. Furthermore, the in vitro results obtained indicate that thymol-chitosan hydrogels are biocompatible when exposed to [3T3] fibroblasts, exhibit antimicrobial activity against Staphylococcus aureus and Streptococcus mutans for 72h and antioxidant activity for 24h. These are desirable properties for a mucosal delivery system for an antimicrobial-antioxidant dual therapy for periodontal disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Microbial transformation of citral by Penicillium sp..

PubMed

Esmaeili, Akbar; Tavassoli, Afsaneh

2010-01-01

Thymol is present in the essential oils from herbs and spices, such as thyme. It is produced by these plant species as a chemical defense against phytopathogenic microorganisms. Therefore, this compound has attracted great attention in food industry, i.e., it has been used as a natural preservative in foods such as cheese to prevent fungal growth. Previous studies concerning the biotransformation of nerol by Penicillium sp. and microbial transformation of citral by sporulated surface cultures method (SSCM) of Penicillium digitatum have been reported. The objective of this research was to study the pathway involved during biotransformation of citral by Penicillium sp. using two methods. The culture preparation was done using different microbial methods and incubation periods to obtain Penicillium for citral biotransformation. The biotransformation products were identified by gas chromatography (GC) and gas chromatography/mass spectroscopy (GC/MS). A comparison of the two methods showed that SSCM was more effective, its major products were thymol (21.5 %), geranial (18.6 %) and nerol (13.7 %). LM produced only one compound — thymol — with a low efficiency.

Assessment of antioxidative, chelating, and DNA-protective effects of selected essential oil components (eugenol, carvacrol, thymol, borneol, eucalyptol) of plants and intact Rosmarinus officinalis oil.

PubMed

Horvathova, Eva; Navarova, Jana; Galova, Eliska; Sevcovicova, Andrea; Chodakova, Lenka; Snahnicanova, Zuzana; Melusova, Martina; Kozics, Katarina; Slamenova, Darina

2014-07-16

Selected components of plant essential oils and intact Rosmarinus officinalis oil (RO) were investigated for their antioxidant, iron-chelating, and DNA-protective effects. Antioxidant activities were assessed using four different techniques. DNA-protective effects on human hepatoma HepG2 cells and plasmid DNA were evaluated with the help of the comet assay and the DNA topology test, respectively. It was observed that whereas eugenol, carvacrol, and thymol showed high antioxidative effectiveness in all assays used, RO manifested only antiradical effect and borneol and eucalyptol did not express antioxidant activity at all. DNA-protective ability against hydrogen peroxide (H2O2)-induced DNA lesions was manifested by two antioxidants (carvacrol and thymol) and two compounds that do not show antioxidant effects (RO and borneol). Borneol was able to preserve not only DNA of HepG2 cells but also plasmid DNA against Fe(2+)-induced damage. This paper evaluates the results in the light of experiences of other scientists.

Ultrasound assisted microextraction-nano material solid phase dispersion for extraction and determination of thymol and carvacrol in pharmaceutical samples: experimental design methodology.

PubMed

Roosta, Mostafa; Ghaedi, Mehrorang; Daneshfar, Ali; Sahraei, Reza

2015-01-15

In the present study, for the first time, a new extraction method based on "ultrasound assisted microextraction-nanomaterial solid phase dispersion (UAME-NMSPD)" was developed to preconcentrate the low quantity of thymol and carvacrol in pharmaceutical samples prior to their HPLC-UV separation/determination. The analytes were accumulated on nickel sulfide nanomaterial loaded on activated carbon (NiS-NP-AC) that with more detail identified by XRD, FESEM and UV-vis technique. Central composite design (CCD) combined with desirability function (DF) was used to search for optimum operational conditions. Working under optimum conditions specified as: 10 min ultrasonic time, pH 3, 0.011 g of adsorbent and 600 μL extraction solvent) permit achievement of high and reasonable linear range over 0.005-2.0 μg mL(-1) (r(2)>0.9993) with LOD of thymol and carvacrol as 0.23 and 0.21 μg L(-1), respectively. The relative standard deviations (RSDs) were less than 4.93% (n=3). Copyright © 2014 Elsevier B.V. All rights reserved.

Plant Essential Oils Synergize and Antagonize Toxicity of Different Conventional Insecticides against Myzus persicae (Hemiptera: Aphididae)

PubMed Central

Faraone, Nicoletta; Hillier, N. Kirk; Cutler, G. Christopher

2015-01-01

Plant-derived products can play an important role in pest management programs. Essential oils from Lavandula angustifolia (lavender) and Thymus vulgaris (thyme) and their main constituents, linalool and thymol, respectively, were evaluated for insecticidal activity and synergistic action in combination with insecticides against green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). The essential oils and their main constituents exerted similar insecticidal activity when aphids were exposed by direct sprays, but were non-toxic by exposure to treated leaf discs. In synergism experiments, the toxicity of imidacloprid was synergized 16- to 20-fold by L. angustifolia and T. vulgaris essential oils, but far less synergism occurred with linalool and thymol, indicating that secondary constituents of the oils were probably responsible for the observed synergism. In contrast to results with imidacloprid, the insecticidal activity of spirotetramat was antagonized by L. angustifolia and T. vulgaris essential oils, and linalool and thymol. Our results demonstrate the potential of plant essential oils as synergists of insecticides, but show that antagonistic action against certain insecticides may occur. PMID:26010088

Dietary Supplementation of Benzoic Acid and Essential Oil Compounds Affects Buffering Capacity of the Feeds, Performance of Turkey Poults and Their Antioxidant Status, pH in the Digestive Tract, Intestinal Microbiota and Morphology

PubMed Central

Giannenas, I.; Papaneophytou, C. P.; Tsalie, E.; Pappas, I.; Triantafillou, E.; Tontis, D.; Kontopidis, G. A.

2014-01-01

Three trials were conducted to evaluate the effect of supplementation of a basal diet with benzoic acid or thymol or a mixture of essential oil blends (MEO) or a combination of benzoic acid with MEO (BMEO) on growth performance of turkey poults. Control groups were fed a basal diet. In trial 1, benzoic acid was supplied at levels of 300 and 1,000 mg/kg. In trial 2, thymol or the MEO were supplied at levels of 30 mg/kg. In trial 3, the combination of benzoic acid with MEO was evaluated. Benzoic acid, MEO and BMEO improved performance, increased lactic acid bacteria populations and decreased coliform bacteria in the caeca. Thymol, MEO and BMEO improved antioxidant status of turkeys. Benzoic acid and BMEO reduced the buffering capacity compared to control feed and the pH values of the caecal content. Benzoic acid and EOs may be suggested as an effective alternative to AGP in turkeys. PMID:25049947

Molecular interactions and redox effects of carvacrol and thymol on myofibrillar proteins using a non-destructive and solvent-free methodological approach.

PubMed

Lahmar, Aida; Akcan, Tolga; Chekir-Ghedira, Leila; Estévez, Mario

2018-04-01

The present study provides molecular insight into the effect of thymol and carvacrol on the oxidative damage caused to myofibrillar proteins by a hydroxyl-radical generating system (HRGS). An innovative model system was designed, in which gels, prepared with increasing levels of myofibrillar proteins, were oxidized by a HRGS (Fe 3+ /H 2 O 2 , 60 °C and 7 days) in the presence of lipids. The molecular affinity between myofibrillar proteins and both terpenes, as well as their effect on the oxidative stability of the gel systems, were studied using a non-destructive and solvent-free procedure based on fluorescence spectroscopy. Carvacrol displayed more affinity than thymol for establishing chemical interactions with protein residues. Both terpenes exhibited a significant antioxidant potential against the generation of lipid-derived volatile carbonyls and against the formation of protein crosslinking. This procedure may be applied to meat products to assess the effectiveness of a given antioxidant additive without size reduction or sample processing. Copyright © 2018 Elsevier Ltd. All rights reserved.

In vitro effects of some herbs used in Egyptian traditional medicine on viability of protoscolices of hydatid cysts.

PubMed

Yones, Doaa A; Taher, Gamal A; Ibraheim, Zedan Z

2011-09-01

The present work evaluated the effects of alcoholic extracts of salvia (Salvia officinalis), thyme (Thymus vulgaris), and 2 pure compounds (thymol and menthol) on the viability of Echinococcus granulosus protoscolices in vitro. Four different concentrations of each extract (2,500, 1,500, 1,000, and 500 µg/ml) and 3 different concentrations each of thymol and menthol (50, 10, and 1 µg/ml) were used. Concentration of 2,500 µg/ml of both extracts showed a significant protoscolicidal activity on the 6th day. Complete loss of viability of protoscolices occurred with 500 µg/ml concentration of both extracts at day 6 and day 7 post-treatment (PT), respectively. Pure compounds, i.e., menthol and thymol, showed potent effects with 50 µg/ml concentration at day 2 and day 5 PT, respectively. These effects were compared with those of albendazole sulfoxide (800 µg/ml), a commonly used treatment drug for hydatidosis. Krebs-Ringer solution and the hydatid cystic fluid at a ratio of 4:1 was a good preservative solution which kept the protoscolices viable for 15 days.

Development of antimicrobial nanoemulsion-based delivery systems against selected pathogenic bacteria using a thymol-rich Thymus daenensis essential oil.

PubMed

Ghaderi, L; Moghimi, R; Aliahmadi, A; McClements, D J; Rafati, H

2017-10-01

Thymol-rich medicinal plants have been used in traditional medicine to relieve infectious diseases. However, the application of essential oils as medicine is limited by its low water solubility and high vapour pressure. The objective of this study was to produce stable nanoemulsions of Thymus daenensis oil in water by preventing Ostwald ripening and phase separation. The antibacterial activity of bulk and emulsified essential oil against selected pathogenic bacteria including Gram-negative (Haemophilus influenzae, Pseudomonas aeruginosa) and Gram-positive (Streptococcus pneumoniae) were investigated in the liquid and vapour phase. The optimum formulation (L2) contained 2% Tween 80 (surfactant) and 0·1% lecithin (cosurfactant) had a mean droplet diameter of 131 nm. In the liquid phase, the optimized nanoemulsion exhibited good antibacterial activity against S. pneumonia with MIC value of 0·0039 mg mL -1 . In the vapour phase, the MIC values against S. pneumonia were similar (<7·35 μL L -1 ) for both bulk and emulsified essential oil. However, there was no antibacterial activity in the vapour phase against H. influenzae and P. aeruginosa. Analysis of thymol concentration in the head space indicated that the nanoemulsion retarded the release of thymol into the vapour phase. These findings highlight the potential applications of nanoemulsions containing essential oils as antibacterial products. The results of the current study highlight the advantages of nanoemulsification for improvement of the physicochemical properties and the antibacterial activity of T. daenensis EOs in the liquid and vapour phase for therapeutic purposes. © 2017 The Society for Applied Microbiology.

Acaricidal efficacies of Lippia gracilis essential oil and its phytochemicals against organophosphate-resistant and susceptible strains of Rhipicephalus (Boophilus) microplus.

PubMed

Costa-Júnior, Livio M; Miller, Robert J; Alves, Péricles B; Blank, Arie F; Li, Andrew Y; Pérez de León, Adalberto A

2016-09-15

Plant-derived natural products can serve as an alternative to synthetic compounds for control of ticks of veterinary and medical importance. Lippia gracilis is an aromatic plant that produces essential oil with high content of carvacrol and thymol monoterpenes. These monoterpenes have high acaricidal activity against Rhipicephalus (Boophilus) microplus. However, there are no studies that show efficacy differences of essential oils between susceptible and organophosphate resistant strains of R. (B.) microplus. The aim of the present study was to compare acaricidal effects of essential oils extracted from two different genotypes of L. gracilis and the main monoterpenes on larvae of both susceptible and organophosphate resistant R. (B.) microplus larvae. The efficacy of the essential oil of two genotypes of L. gracilis (106 and 201) and their monoterpenes carvacrol and thymol was measured using the larval immersion test on coumaphos-resistant and susceptible strains of R. (B.) microplus. Lethal concentrations were calculated using GraphPad Prism 6.0. Chemical analysis was performed by GC-MS and FID. Thymol and carvacrol were observed to be major constituents in 106 and 201L. gracilis genotype essential oils, respectively. Essential oils of both genotypes were more effective against organophosphate-resistant tick strain than susceptible tick strain. Carvacrol was 3.2 times more toxic to organophosphate resistant strain than to susceptible strain. Thymol was equally toxic to resistant and susceptible tick strains. The significantly higher efficacy monoterpene carvacrol against resistant ticks may lead to development of new natural product acaricide formulations for use to control organophosphate resistant R. (B.) microplus populations. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of UV Rays and Thymol/Thymus vulgaris L. Extract in an ex vivo Human Skin Model: Morphological and Genotoxicological Assessment.

PubMed

Cornaghi, Laura; Arnaboldi, Francesca; Calò, Rossella; Landoni, Federica; Baruffaldi Preis, William Franz; Marabini, Laura; Donetti, Elena

2016-01-01

Ultraviolet (UV) radiation is the major environmental factor affecting functions of the skin. Compounds rich in polyphenols, such as Thymus vulgaris leaf extract and thymol, have been proposed for the prevention of UV-induced skin damage. We compared the acute effects induced by UVA and UVB rays on epidermal morphology and proliferation, cytotoxicity, and genotoxicity. Normal human skin explants were obtained from young healthy women (n = 7) after informed consent and cultured at the air-liquid interface overnight. After 24 h, the samples were divided in 2 groups: the former exposed to UVA (16 or 24 J/cm2) and the latter irradiated with UVB (0.24 or 0.72 J/cm2). One hour after the end of irradiation, supernatants were collected for evaluation of the lactate dehydrogenase activity. Twenty-four hours after UVB exposure, biopsies were processed for light and transmission electron microscopy analysis, proliferation, cytotoxicity, and genotoxicity. UVB and UVA rays induced early inhibition of cell proliferation and DNA damage compared to controls. In particular, UVB rays were always more cytotoxic and genotoxic than UVA ones. For this reason, we evaluated the effect of either T. vulgaris L. extract (1.82 µg/ml) or thymol (1 µg/ml) on all samples treated for 1 h before UVB irradiation. While Thymus had a protective action for all of the endpoints evaluated, the action of the extract was less pronounced on epidermal proliferation and morphological features. The results presented in this study could be the basis for investigating the mechanism of thymol and T. vulgaris L. extract against the damage induced by UV radiation. © 2016 S. Karger AG, Basel.

Chemical composition and anti-biofilm activity of Thymus sipyleus BOISS. subsp. sipyleus BOISS. var. davisianus RONNIGER essential oil.

PubMed

Ceylan, Ozgur; Ugur, Aysel

2015-06-01

In this study, antimicrobial and antibiofilm activities and the chemical composition of Thymus sipyleus BOISS. subsp. sipyleus BOISS. var. davisianus RONNIGER essential oil was evaluated. The essential oil was obtained by hydro-distillation and analyzed by gas chromatography-mass spectrometry. Fourteen compounds were characterized, having as major components thymol (38.31%) and carvacrol (37.95%). Minimum inhibitory concentrations (MICs) of oil and the major components were calculated by serial dilution method, and anti-biofilm effects by microplate biofilm assay against five Gram positive (Staphylococcus aureus MU 38, MU 40, MU 46, MU 47, Stahylococcus epidermidis MU 30) and five Gram negative (Pseudomonas aeruginosa MU 187, MU 188, MU 189, Pseudomonas fluorescens MU 180, MU 181) bacteria. It was found that MICs for essential oil, thymol and carvacrol were between 5 and 50 µl/ml, 0.125-0.5 µg/ml and 0.125-05 µl/ml, respectively. The results showed that doses of MIC produced a greater anti-biofilm influence than 0.5, 0.25 and 0.125 MIC. In the presence of essential oil (MIC), the mean biofilm formation value was equal to 67 ± 5.5% for P. aeruginosa MU 188, and essential oil (MIC) inhibition exceeds 60% for P. aeruginosa biofilms. The results also showed that carvacrol (MIC) was able to induce an inhibition 72.9 ± 4.1% for S.aureus (MU 40) biofilm. In addition, thymol (MIC) showed 68.6 ± 5.3% reduction in biofilm formation of P. fluorescens MU 181. This study demonstrated the antimicrobial and antibiofilm activity of T. sipyleus BOISS. subsp. sipyleus BOISS. var. davisianus RONNIGER essential oil and points out the exceptional efficiency of thymol and carvacrol, which could represent candidates in the treatment of Pseudomonas and Staphylococcus biofilms.

Destruction of Opportunistic Pathogens via Polymer Nanoparticle-Mediated Release of Plant-Based Antimicrobial Payloads

PubMed Central

Amato, Dahlia N.; Amato, Douglas V.; Mavrodi, Olga V.; Braasch, Dwaine A.; Walley, Susan E.; Douglas, Jessica R.

2017-01-01

The synthesis of antimicrobial thymol/carvacrol-loaded polythioether nanoparticles (NPs) via a one-pot, solvent-free miniemulsion thiol-ene photopolymerization process is reported. The active antimicrobial agents, thymol and carvacrol, are employed as “solvents” for the thiol-ene monomer phase in the miniemulsion to enable facile high capacity loading (≈50% w/w), excellent encapsulation efficiencies (>95%), and elimination of all postpolymerization purification processes. The NPs serve as high capacity reservoirs for slow-release and delivery of thymol/carvacrol-combination payloads that exhibit inhibitory and bactericidal activity (>99.9% kill efficiency at 24 h) against gram-positive and gram-negative bacteria, including both saprophytic (Bacillus subtilis ATCC 6633 and Escherichia coli ATCC 25922) and pathogenic species (E. coli ATCC 43895, Staphylococcus aureus RN6390, and Burkholderia cenocepacia K56-2). This report is among the first to demonstrate antimicrobial efficacy of essential oil-loaded nanoparticles against B. cenocepacia – an innately resistant opportunistic pathogen commonly associated with debilitating respiratory infections in cystic fibrosis. Although a model platform, these results point to promising pathways to particle-based delivery of plant-derived extracts for a range of antimicrobial applications, including active packaging materials, topical antiseptics, and innovative therapeutics. PMID:26946055

Antifungal efficacy of thymol, carvacrol, eugenol and menthol as alternative agents to control the growth of food-relevant fungi.

PubMed

Abbaszadeh, S; Sharifzadeh, A; Shokri, H; Khosravi, A R; Abbaszadeh, A

2014-06-01

This work is an attempt to examine the antifungal activity of thymol, carvacrol, eugenol and menthol against 11 food-decaying fungi. The susceptibility test for the compounds was carried out in terms of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) using microdilution method in 96 multi-well microtiter plates. Results indicated that all compounds were effective to varying extents against various fungal isolates, with the highest efficacy displayed by carvacrol (mean MIC value: 154.5 μg/mL) (P<0.05). The incorporation of increased concentrations of all compounds to the media led to progressive and significant reduction in growth for all fungi. The most potent inhibitory activity of thymol, carvacrol, eugenol and menthol was found for Cladosporium spp. (MIC: 100 μg/mL), Aspergillus spp. (MIC: 100 μg/mL), Cladosporium spp. (MIC: 350 μg/mL), and Aspergillus spp. and Cladosporium spp. (MIC: 125 μg/mL), respectively. Thus, the application of these herbal components could be considered as a good alternatives to inhibit fungal growth and to reduce the use of synthetic fungicides. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Efficacy of Essential Oils of Thymus vulgaris and Origanum vulgare on Echinococcus granulosus

PubMed Central

Pensel, P. E.; Maggiore, M. A.; Gende, L. B.; Eguaras, M. J.; Denegri, M. G.; Elissondo, M. C.

2014-01-01

The aim of the present work was to determine the in vitro effect of T. vulgaris and O. vulgare essential oils against E. granulosus protoscoleces and cysts. Essential oils were added to the medium resulting in thymol final concentrations of 10 μg/mL. The essential oils had a time-dependent effect provoking the complete loss of protoscolex viability after 72 days of postincubation. The results were confirmed at the ultrastructure level. Loss of infectivity in protoscoleces incubated with O. vulgare after 60 days was observed. On the other hand, the weight of cysts recorded in mice inoculated with T. vulgaris treated protoscoleces was significantly lower than that obtained in control group. Gamma-glutamyl-transpeptidase activity was readily detected in the culture supernatant of protoscoleces treated either with the essential oils or thymol. T. vulgaris and O. vulgare essential oils and thymol can induce cell apoptosis of protoscoleces after short incubation times. The efficacy of T. vulgaris and O. vulgare essential oils was also demonstrated in vitro on E. granulosus murine cysts. Our data suggest that essential oils of T. vulgaris and O. vulgare have anthelmintic effect against protoscoleces and cysts of E. granulosus. PMID:25180033

The effect of diets supplemented with thyme essential oils and rosemary extract on the deterioration of farmed gilthead seabream (Sparus aurata) during storage on ice.

PubMed

Álvarez, A; García García, B; Jordán, M J; Martínez-Conesa, C; Hernández, M D

2012-06-01

The effect on quality were assessed for gilthead seabream fed five different diets: control (basal diet); BHT (basal diet with 200mgkg -1 of butylated hydroxytoluene); rosemary (basal diet with 600mgkg -1 of rosemary extract -Rosmarinus officinalis); carvacrol (basal diet with 500mgkg -1 of essential oil of Thymbra capitata, carvacrol chemotype); and thymol (basal diet with 500mgg -1 of essential oil of Thymus zygis, subspecies gracilis, thymol chemotype). After 18weeks of experimentation, the animals were stored on ice at 4°C for 0, 7, 14, and 21days. Physical-chemical, microbiological and sensory analyses were carried out at each sampling point to determine the degree of deterioration in the gilthead seabream. Lower indices of oxidation were observed in animals who were administered feeds supplemented with BHT, carvacrol and (to a lesser degree) rosemary. Lower bacteria counts were observed for the BHT and thymol groups, in addition to a slower deterioration in terms of sensory perception. Accordingly, the addition of natural antioxidants to the diet may have an added effect on fish quality, delaying post mortem deterioration. Copyright © 2011 Elsevier Ltd. All rights reserved.

Phenolic constituents from the roots of Mikania micrantha and their allelopathic effects.

PubMed

Xu, Qiaolin; Xie, Haihui; Xiao, Huilin; Wei, Xiaoyi

2013-07-31

Four new thymol derivatives, 8,10-dihydroxy-9-benzoyloxythymol (1), 9-isobutyryloxy-10-hydroxythymol (2), 7,8,9,10-tetrahydroxythymol (3), and 7,8,10-trihydroxy-9-E-feruloyloxythymol (4), were isolated from the fresh roots of Mikania micrantha , along with 8,9,10-trihydroxythymol (5), 8,10-dihydroxy-9-acetoxythymol (6), 8,10-dihydroxy-9-isobutyryloxythymol (7), 8,10-dihydroxy-9-(2-methylbutyryloxy)thymol (8), 8,9-dehydro-10-hydroxythymol (9), 8-methoxy-9-hydroxythymol (10), ethyl caffeate (11), ethyl ferulate (12), 3,5-di-O-caffeoylquinic acid (13), and mikanin (14). Their structures were determined by spectroscopic methods. The known thymol derivatives (5-10) were obtained from the genus Mikania for the first time. Allelopathic effects of these compounds on Arabidopsis thaliana seeds were evaluated by a filter paper assay. After the treatment at 0.1 mM for 4 days, the seed germination rate with compound 8 was 48% and the inhibitory rates of shoot growth with compounds 1, 2, 7-10, and 12 were over 40%. The IC50 values of compounds 1 and 8 on shoot growth were 342.5 and 625 μM, respectively.

In-vitro effects of Thymus munbyanus essential oil and thymol on human sperm motility and function.

PubMed

Chikhoune, Amirouche; Stouvenel, Laurence; Iguer-Ouada, Mokrane; Hazzit, Mohamed; Schmitt, Alain; Lorès, Patrick; Wolf, Jean Philippe; Aissat, Kamel; Auger, Jacques; Vaiman, Daniel; Touré, Aminata

2015-09-01

Traditional medicine has been used worldwide for centuries to cure or prevent disease and for male or female contraception. Only a few studies have directly investigated the effects of herbal compounds on spermatozoa. In this study, essential oil from Thymus munbyanus was extracted and its effect on human spermatozoa in vitro was analysed. Gas chromatography and Gas chromatography-mass spectrometry analyses identified 64 components, accounting for 98.9% of the composition of the oil. The principal components were thymol (52.0%), γ-terpinene (11.0%), ρ-cymene (8.5%) and carvacrol (5.2%). Freshly ejaculated spermatozoa was exposed from control individuals to various doses of the essential oil for different time periods, and recorded the vitality, the mean motility, the movement characteristics (computer-aided sperm analysis), the morphology and the ability to undergo protein hyperphosphorylation and acrosomal reaction, which constitute two markers of sperm capacitation and fertilizing ability. In vitro, both the essential oil extracted from T. munbyanus and thymol, the principal compound present in this oil, impaired human sperm motility and its capacity to undergo hyperphosphorylation and acrosome reaction. These compounds may, therefore, be of interest in the field of reproductive biology, as potential anti-spermatic agents. Copyright © 2015 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Destruction of Opportunistic Pathogens via Polymer Nanoparticle-Mediated Release of Plant-Based Antimicrobial Payloads.

PubMed

Amato, Dahlia N; Amato, Douglas V; Mavrodi, Olga V; Braasch, Dwaine A; Walley, Susan E; Douglas, Jessica R; Mavrodi, Dmitri V; Patton, Derek L

2016-05-01

The synthesis of antimicrobial thymol/carvacrol-loaded polythioether nanoparticles (NPs) via a one-pot, solvent-free miniemulsion thiol-ene photopolymerization process is reported. The active antimicrobial agents, thymol and carvacrol, are employed as "solvents" for the thiol-ene monomer phase in the miniemulsion to enable facile high capacity loading (≈50% w/w), excellent encapsulation efficiencies (>95%), and elimination of all postpolymerization purification processes. The NPs serve as high capacity reservoirs for slow-release and delivery of thymol/carvacrol-combination payloads that exhibit inhibitory and bactericidal activity (>99.9% kill efficiency at 24 h) against gram-positive and gram-negative bacteria, including both saprophytic (Bacillus subtilis ATCC 6633 and Escherichia coli ATCC 25922) and pathogenic species (E. coli ATCC 43895, Staphylococcus aureus RN6390, and Burkholderia cenocepacia K56-2). This report is among the first to demonstrate antimicrobial efficacy of essential oil-loaded nanoparticles against B. cenocepacia - an innately resistant opportunistic pathogen commonly associated with debilitating respiratory infections in cystic fibrosis. Although a model platform, these results point to promising pathways to particle-based delivery of plant-derived extracts for a range of antimicrobial applications, including active packaging materials, topical antiseptics, and innovative therapeutics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bumble bee parasite strains vary in resistance to phytochemicals

PubMed Central

Palmer-Young, Evan C.; Sadd, Ben M.; Stevenson, Philip C.; Irwin, Rebecca E.; Adler, Lynn S.

2016-01-01

Nectar and pollen contain diverse phytochemicals that can reduce disease in pollinators. However, prior studies showed variable effects of nectar chemicals on infection, which could reflect variable phytochemical resistance among parasite strains. Inter-strain variation in resistance could influence evolutionary interactions between plants, pollinators, and pollinator disease, but testing direct effects of phytochemicals on parasites requires elimination of variation between bees. Using cell cultures of the bumble bee parasite Crithidia bombi, we determined (1) growth-inhibiting effects of nine floral phytochemicals and (2) variation in phytochemical resistance among four parasite strains. C. bombi growth was unaffected by naturally occurring concentrations of the known antitrypanosomal phenolics gallic acid, caffeic acid, and chlorogenic acid. However, C. bombi growth was inhibited by anabasine, eugenol, and thymol. Strains varied >3-fold in phytochemical resistance, suggesting that selection for phytochemical resistance could drive parasite evolution. Inhibitory concentrations of thymol (4.53–22.2 ppm) were similar to concentrations in Thymus vulgaris nectar (mean 5.2 ppm). Exposure of C. bombi to naturally occurring levels of phytochemicals—either within bees or during parasite transmission via flowers—could influence infection in nature. Flowers that produce antiparasitic phytochemicals, including thymol, could potentially reduce infection in Bombus populations, thereby counteracting a possible contributor to pollinator decline. PMID:27883009

Bumble bee parasite strains vary in resistance to phytochemicals.

PubMed

Palmer-Young, Evan C; Sadd, Ben M; Stevenson, Philip C; Irwin, Rebecca E; Adler, Lynn S

2016-11-24

Nectar and pollen contain diverse phytochemicals that can reduce disease in pollinators. However, prior studies showed variable effects of nectar chemicals on infection, which could reflect variable phytochemical resistance among parasite strains. Inter-strain variation in resistance could influence evolutionary interactions between plants, pollinators, and pollinator disease, but testing direct effects of phytochemicals on parasites requires elimination of variation between bees. Using cell cultures of the bumble bee parasite Crithidia bombi, we determined (1) growth-inhibiting effects of nine floral phytochemicals and (2) variation in phytochemical resistance among four parasite strains. C. bombi growth was unaffected by naturally occurring concentrations of the known antitrypanosomal phenolics gallic acid, caffeic acid, and chlorogenic acid. However, C. bombi growth was inhibited by anabasine, eugenol, and thymol. Strains varied >3-fold in phytochemical resistance, suggesting that selection for phytochemical resistance could drive parasite evolution. Inhibitory concentrations of thymol (4.53-22.2 ppm) were similar to concentrations in Thymus vulgaris nectar (mean 5.2 ppm). Exposure of C. bombi to naturally occurring levels of phytochemicals-either within bees or during parasite transmission via flowers-could influence infection in nature. Flowers that produce antiparasitic phytochemicals, including thymol, could potentially reduce infection in Bombus populations, thereby counteracting a possible contributor to pollinator decline.

The influence of MAP condition and active compounds on the radiosensitization of Escherichia coli and Salmonella typhi present in chicken breast

NASA Astrophysics Data System (ADS)

Lacroix, M.; Chiasson, F.

2004-09-01

The efficiency of carvacrol, thymol, trans-cinnamaldehyde (Tc) and tetrasodium pyrophosphate (Tp) on the radiosensitization of Escherichia coli and Salmonella typhi in chicken breast was determined. Chicken breast were dipped in a bath of working cultures of E. coli or S. typhi (5×10 7 CFU/ml). Active compounds were added at the concentration corresponding to {1}/{30} of the minimal inhibitory concentration. Samples were packed under air and gamma irradiation was done at doses from 0.1 to 0.7 kGy. The efficiencies of the active compounds against E. coli were 32%, 10%, 3% and 0% for thymol, Tp and carvacrol, respectively. For S. typhi, the efficiencies in the chicken breast were 47%, 19%, 17% and 11% for Tc, Tp, carvacrol and thymol, respectively. Without active compounds, D10 values were 0.145 kGy for E. coli and 0.64 kGy for S. typhi as compared to 0.098 kGy for E. coli and 0.341 kGy for S. typhi in presence of Tc. Under modified atmospheric packaging condition and in presence of Tc, D10 values were reduced to 0.046 for E. coli and to 0.110 for S. typhi.

Use of natural antimicrobials to increase antibiotic susceptibility of drug resistant bacteria.

PubMed

Palaniappan, Kavitha; Holley, Richard A

2010-06-15

Plant-derived antibacterial compounds may be of value as a novel means for controlling antibiotic resistant zoonotic pathogens which contaminate food animals and their products. Individual activity of natural antimicrobials (eugenol, thymol, carvacrol, cinnamaldehyde, allyl isothiocyanate (AIT)) and activity when paired with an antibiotic was studied using broth microdilution and checkerboard methods. In the latter assays, fractional inhibitory concentration (FIC) values were calculated to characterize interactions between the inhibitors. Bacteria tested were chosen because of their resistance to at least one antibiotic which had a known genetic basis. Substantial susceptibility of these bacteria toward the natural antimicrobials and a considerable reduction in the minimum inhibitory concentrations (MIC's) of the antibiotics were noted when paired combinations of antimicrobial and antibiotic were used. In the interaction study, thymol and carvacrol were found to be highly effective in reducing the resistance of Salmonella Typhimurium SGI 1 (tet A) to ampicillin, tetracycline, penicillin, bacitracin, erythromycin and novobiocin (FIC<0.4) and resistance of Streptococcus pyogenes ermB to erythromycin (FIC<0.5). With Escherichia coli N00 666, thymol and cinnamaldehyde were found to have a similar effect (FIC<0.4) in reducing the MIC's of ampicillin, tetracycline, penicillin, erythromycin and novobiocin. Carvacrol, thymol (FIC<0.3) and cinnamaldehyde (FIC<0.4) were effective against Staphylococcus aureus blaZ and in reducing the MIC's of ampicillin, penicillin and bacitracin. Allyl isothiocyanate (AIT) was effective in reducing the MIC of erythromycin (FIC<0.3) when tested against S. pyogenes. Fewer combinations were found to be synergistic when the decrease in viable population (log DP) was calculated. Together, fractional inhibitory concentrations < or = 0.5 and log DP<-1 indicated synergistic action between four natural antimicrobials and as many as three antibiotics to which these bacteria were normally resistant. Copyright 2010 Elsevier B.V. All rights reserved.

In vitro antifungal activity of terpinen-4-ol, eugenol, carvone, 1,8-cineole (eucalyptol) and thymol against mycotoxigenic plant pathogens.

PubMed

Morcia, C; Malnati, M; Terzi, V

2012-01-01

The aim of this study was to examine the effect of five naturally occurring compounds from essential oils on 10 different species of mycotoxigenic fungi involved in several plant diseases. The antifungal activities of terpinen-4-ol, eugenol, carvone, 1,8-cineole (eucalyptol) and thymol were observed in vitro on Fusarium subglutinans, Fusarium cerealis, Fusarium verticillioides, Fusarium proliferatum, Fusarium oxysporum, Fusarium sporotrichioides, Aspergillus tubingensis, Aspergillus carbonarius, Alternaria alternata and Penicillium sp. The naturally occurring compounds tested showed toxic effects on in vitro mycelium growth of all fungal species but with different level of potency. The results are encouraging for further investigations of in planta antifungal activities of these essential oils components.

Essential Oil Characterization of Thymus vulgaris from Various Geographical Locations

PubMed Central

Satyal, Prabodh; Murray, Brittney L.; McFeeters, Robert L.; Setzer, William N.

2016-01-01

Thyme (Thymus vulgaris L.) is a commonly used flavoring agent and medicinal herb. Several chemotypes of thyme, based on essential oil compositions, have been established, including (1) linalool; (2) borneol; (3) geraniol; (4) sabinene hydrate; (5) thymol; (6) carvacrol, as well as a number of multiple-component chemotypes. In this work, two different T. vulgaris essential oils were obtained from France and two were obtained from Serbia. The chemical compositions were determined using gas chromatography–mass spectrometry. In addition, chiral gas chromatography was used to determine the enantiomeric compositions of several monoterpenoid components. The T. vulgaris oil from Nyons, France was of the linalool chemotype (linalool, 76.2%; linalyl acetate, 14.3%); the oil sample from Jablanicki, Serbia was of the geraniol chemotype (geraniol, 59.8%; geranyl acetate, 16.7%); the sample from Pomoravje District, Serbia was of the sabinene hydrate chemotype (cis-sabinene hydrate, 30.8%; trans-sabinene hydrate, 5.0%); and the essential oil from Richerenches, France was of the thymol chemotype (thymol, 47.1%; p-cymene, 20.1%). A cluster analysis based on the compositions of these essential oils as well as 81 additional T. vulgaris essential oils reported in the literature revealed 20 different chemotypes. This work represents the first chiral analysis of T. vulgaris monoterpenoids and a comprehensive description of the different chemotypes of T. vulgaris. PMID:28231164

Environmental and seasonal impacts on the chemical composition of Satureja horvatii Šilić (Lamiaceae) essential oils.

PubMed

Lakušić, Branislava; Ristić, Mihailo; Slavkovska, Violeta; Milenković, Marina; Lakušić, Dmitar

2011-03-01

The chemical composition of the essential oils of Satureja horvatii Šilić from two natural habitats (Mt. Orjen and Mt. Lovćen in Montenegro) and from cultivated plants (Belgrade, Serbia) were characterized. For the latter, plants from the locus classicus, i.e., Orjenske Lokve (Mt. Orjen), were transferred to Belgrade and, after three years of cultivation, the chemical composition of their essential oils at different phenological stages was analyzed. The essential oils were obtained from the aerial parts of the plants by hydrodistillation and analyzed by GC and GC/MS. The yields and chemical compositions of the S. horvatii oils showed significant differences between the plants collected in the natural habitats and those from cultivation, as well as between the plants at different phenological stages. In the populations from the natural habitats, growing in Mediterranean conditions, the most abundant oil constituents were the phenols thymol (63.7% in the samples from Mt. Orjen) or carvacrol (68.1% in the samples from Mt. Lovćen), while the oils from the cultivated plants (Belgrade), growing in continental conditions, were dominated by linalool (up to 65.8 and 55.9% in average). The basic characteristics of the essential oil from plants at the early phenological stage (before flowering) were high percentages of linalool (37.4%), thymol (27.3%), and carvacrol (12.2%). At the stage of flowering, the percentage of linalool (56.6-57.5%) increased, while those of thymol (15.5-15.8%) and carvacrol (1.4-1.5%) significantly decreased. The essential oil of plants in the full stage of fruiting was characterized by the domination of linalool (58.4 and 65.8%) and lower percentages of thymol (7.6 and 1.3%) and carvacrol (0.7 and 0.1%). In conclusion, the oil composition of S. horvatii was found to depend on the pedoclimatic conditions of the habitat and the phenological stage of the plants. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

Determination of some volatile compounds in alcoholic beverage by headspace solid-phase microextraction gas chromatography - mass spectrometry

NASA Astrophysics Data System (ADS)

Schmutzer, G.; Avram, V.; Feher, I.; David, L.; Moldovan, Z.

2012-02-01

The volatile composition of alcoholic beverage was studied by headspace solid-phase microextraction (HSSPME) method and gas chromatography - mass spectrometry (GC-MS). Some volatile compounds, such as alcohols, esters, terpenes and other are mainly responsible for the flavor of fortified wines and their amounts specify the quality of the alcoholic beverages. From this perspective it is interesting to develop a rapid, selective and sensitive analytical method suitable for simultaneous quantification of the main molecules being responsible for the organoleptic characteristic of alcoholic beverages. Vermouth fortified drink was analyzed in order to characterize the volatile profile. Using the HS-SPME/GC-MS a number of twenty-six volatile compounds from a commercial market alcoholic beverage were identified. The most abundant compounds were m-thymol, o-thymol and eugenol, alongside of the ethyl ester compounds.

Effect of a chlorhexidine/thymol and a fluoride varnish on caries development in erupting permanent molars: a comparative study.

PubMed

Flamee, S; Gizani, S; Caroni, C; Papagiannoulis, L; Twetman, S

2015-12-01

To compare the caries preventive effect of a chlorhexidine/thymol-containing antibacterial varnish with a fluoride varnish when topically applied during the eruption of permanent molars. The study group consisted of 189 patients, 5-14 years of age, with one 1st or 2nd permanent molar in the process of eruption. After stratification for type of molar and stage of eruption, the patients were randomised to either quarterly topical applications with an antibacterial varnish (Cervitec(®) Plus; CV group) or biannual applications with a fluoride varnish plus biannual treatments with placebo varnish (Fluor Protector; FV group). The duration of the study was 2 years. The primary endpoint was caries incidence (initial and cavitated) in the erupting molars and the secondary outcome was salivary mutans streptococci (MS) counts. The groups were balanced with respect to socio-economy, oral hygiene, dietary habits and caries experience at baseline. The dropout rate was 11.6 %. The caries incidence was low (< 10 %) in both groups and there was no significant difference between the CV and FV groups with respect to occlusal caries development in the erupting molars (relative risk 1.08, 95 % CI 0.94-1.25). Significantly lower levels of salivary MS were disclosed in the CV group at the end of the study (p < 0.05). No difference in occlusal caries development in young permanent molars was displayed after topical applications of either a chlorhexidine/thymol varnish or a fluoride varnish during tooth eruption.

Promising biocidal activity of thymol loaded chitosan silver nanoparticles (T-C@AgNPs) as anti-infective agents against perilous pathogens.

PubMed

Manukumar, H M; Umesha, S; Kumar, H N Naveen

2017-09-01

The advent of biodegradable polymer-encapsulated drug nanoparticles has made an exciting area of drug delivery research. The present study investigated novel and simple route for synthesis of thymol loaded chitosan silver nanoparticles (T-C@AgNPs) using chitosan and thymol as reducing, capping agent respectively to understand the therapeutic efficacy. The UV-vis spectroscopy, DLS, FT-IR, SEM, EDS, XRD used for characterization and radical scavenging activity, anti-microbial and biocompatibility was taken to ascertain an efficacy of novel T-C@AgNPs. The T-C@AgNPs intense peak at 490nm indicates the formation of nanoparticles and had average particle size of 28.94nm with spherical shape, monodisperse state in water, also exhibited excellent biocompatibility of cubic shaped pure silver element containing T-C@AgNPs. The antibacterial activity was studied for gram positive and gram negative food-borne pathogens and effective inhibition at 100μgmL -1 to S. aureus, S. epidermidis, S. haemolyticus (10.08, 10.00, 11.23mm) and S. typhimurium, P. aeruginosa and S. flexneri (9.28, 9.33, 12.03mm) compared to antibiotic Streptomycin. This study revealed the efficacy against multiple food-borne pathogens and therapeutic efficacy of T-C@AgNPs offers a valuable contribution in the area of nanotechnology. This proved to be a first-class novel antimicrobial material for the first time in this study. Copyright © 2017 Elsevier B.V. All rights reserved.

An Olfactory Indicator for Acid-Base Titrations.

ERIC Educational Resources Information Center

Flair, Mark N.; Setzer, William N.

1990-01-01

The use of an olfactory acid-base indicator in titrations for visually impaired students is discussed. Potential olfactory indicators include eugenol, thymol, vanillin, and thiophenol. Titrations performed with each indicator with eugenol proved to be successful. (KR)

Essential oil composition of aerial parts of Micromeria persica Boiss. from Western of Shiraz, Iran.

PubMed

Jafari, Efat; Ghanbarian, Gholamabbas; Bahmanzadegan, Atefeh

2018-04-01

Micromeria persica Boiss. is medicinal and aromatic plant, belonging to the Lamiaceae family. The chemical composition of the essential oils (EOs) from aerial parts of M. persica were extracted using hydro-distillation method and analysed using GC and GC-MS. Fifty-two compounds were identified in the EOs of aerial parts of M. persica. The main chemical compositions were n-hexadecanoic acid (14.9%), thymol (9.5%), linoleic acid (8.0%), carvacrol (5.6%), (E)-nerolidol (5.5%), linolenic acid (5.5%), α-cadinol (2.7%), linalool (2.7%), borneol (2.6%), caryophyllene oxide (2.3%) and pulegone (2.0%). Presence of borneol, thymol, carvacrol and pulegone suggests the potential of this plant as a flavouring source in the food industry, being used in perfumery and cosmetics industry, vitamin E synthesis and exhibit strong fungicidal, antibacterial and antimicrobial activities.

Characterisation of TruView™: a new 3-D reusable radiochromic MethylThymolBlue based gel dosimeter for ionising radiations

NASA Astrophysics Data System (ADS)

Colnot, J.; Huet, C.; Clairand, I.

2017-05-01

TruView™ is a new water-equivalent reusable Fricke gel dosimeter based on MethylThymolBlue reactive dye. Details of the characterisation of the TruView™ MTB gel dosimeter by spectrophotometric measurements and of its reading with the Optical-CT Scanner Vista™ are described. In this study, the different parameters influencing TruView™ dose response have been studied and its performances have been compared to chamber and diodes measurements. This gel presents a linear response with dose up to 20 Gy, independent in the investigated range of photon beam energy and dose rate and also a good intra-batch uniformity. Ions diffusion into the matrix homogenizes the gel after a week, losing dosimetric information but allowing a new irradiation to be performed. However, auto-oxidation happens before and after irradiation, degrading the dosimeter response and stability. Storage and reading conditions affect the response as well.

Inhibitory effects of selected Turkish spices and oregano components on some foodborne fungi.

PubMed

Akgül, A; Kivanç, M

1988-05-01

The inhibitory effects of 10 selected Turkish spices, oregano essential oil, thymol and carvacrol towards growth of 9 foodborne fungi were investigated in culture media with pH 3.5 and 5.5. The antifungal effects of sodium chloride, sorbic acid and sodium benzoate and the combined use of oregano with sodium chloride were also tested under the same conditions for comparison. Of the spices tested, only sodium chloride were also tested under the same conditions for comparison. Of the spices tested, only oregano at 1.0, 1.5, 2.0% (w/v) levels showed effect on all fungi. 8% (w/v) sodium chloride was less effective than oregano. Oregano essential oil, thymol or carvacrol at concentrations of 0.025% and 0.05% completely inhibited the growth of all fungi, showing greater inhibition than sorbic acid at the same concentrations. The combined use of oregano and sodium chloride exhibited a synergistic antifungal effect.

Insecticidal properties of essential plant oils against the mosquito Culex pipiens molestus (Diptera: Culicidae).

PubMed

Traboulsi, Abdallah F; Taoubi, K; el-Haj, Samih; Bessiere, J M; Rammal, Salma

2002-05-01

The insecticidal activities of essential oil extracts from leaves and flowers of aromatic plants against fourth-instar larvae of the mosquito Culex pipiens molestus Forskal were determined. Extracts of Myrtus communis L were found to be the most toxic, followed by those of Origanum syriacum L, Mentha microcorphylla Koch, Pistacia lentiscus L and Lavandula stoechas L with LC50 values of 16, 36, 39, 70 and 89 mg litre-1, respectively. Over 20 major components were identified in extracts from each plant species. Eight pure components (1,8-cineole, menthone, linalool, terpineol, carvacrol, thymol, (1S)-(-)-alpha-pinene and (1R)-(+)-alpha-pinene) were tested against the larvae. Thymol, carvacrol, (1R)-(+)-alpha-pinene and (1S)-(-)-alpha-pinene were the most toxic (LC50 = 36-49 mg litre-1), while menthone, 1,8-cineole, linalool and terpineol (LC50 = 156-194 mg litre-1) were less toxic.

Field efficacy of acaricides against Varroa destructor

PubMed Central

Gracia, María Jesús; Moreno, Carlos; Ferrer, Montserrat; Sanz, Alfredo; Peribáñez, Miguel Ángel; Estrada, Rosa

2017-01-01

Field trials were conducted in Northeast Spain (Aragón) to evaluate the effectiveness of two acaricides against Varroa destructor. These experiments took into account the season of the year, apiary, colony, and developmental state and strength of the colony. The acaricides used were a synthetic (amitraz, Apivar®) and a natural (formulated from Api Life Var®, thymol oil and thymol alcohol) product. The treatments used in the present study reduce high infestations of V. destructor, although they do not eliminate the infestation. Similar efficacies between treatments were found. Nevertheless, the efficacy of a treatment depends on the apiary where applied. Moreover, the detected variability in the apiary and hive poses a challenge to the identification of the significant factors. Therefore, more field studies to assess efficacies in several apiaries are needed to obtain a better understanding of the effects of the applied treatments. PMID:28158303

Effect of storage solutions on microhardness of crown enamel and dentin.

PubMed

Aydın, Berdan; Pamir, Tijen; Baltaci, Aysun; Orman, Mehmet N; Turk, Tugba

2015-01-01

The aim of this study was to determine alterations in microhardness of crown dentin and enamel, after 2 and 12-month storage in de-ionized water, 0.2% glutaraldehyde, Hanks' Balanced Salt Solution (HBSS), 0.1% sodium hypochlorite (NaOCl) or 0.1% thymol. Freshly extracted, nonsterile 60 intact human premolars were distributed to five groups. Six teeth from each group were evaluated after two, and other six teeth were evaluated after 12 months storage. After grinding and polishing of teeth, Vickers hardness was evaluated with making indentations on enamel and dentin, using a pyramid diamond indenter tip exerting 100 g load for 15 s. After 2 months storage in solutions, range of the hardness values (HV) of enamel and dentin were in between 315-357 and 64-67, respectively. However, 12 months storage of the teeth resulted in a statistically significant decrease in microhardness when compared to microhardness of teeth stored for 2 months (P = 0.001). Although the differences were not significant regarding solutions, all solutions decreased the microhardness both in enamel and dentin (P > 0.05). However, decrease in microhardness was relatively less in de-ionized water and thymol solutions while glutaraldehyde decreased microhardness the most: 63% for enamel and 53% for dentin. Microhardness of enamel and dentin was in an acceptable range when teeth were stored for 2 months in de-ionized water, glutaraldehyde, HBSS, NaOCl or in thymol; thus, teeth kept up to 2 months in these solutions can be used for mechanical in vitro tests. However, 12 months storage significantly decreased the microhardness of enamel and dentin.

Antimicrobial activity of the essential oil from Lippia sidoides, carvacrol and thymol against oral pathogens.

PubMed

Botelho, M A; Nogueira, N A P; Bastos, G M; Fonseca, S G C; Lemos, T L G; Matos, F J A; Montenegro, D; Heukelbach, J; Rao, V S; Brito, G A C

2007-03-01

Dental caries and periodontal disease are associated with oral pathogens. Several plant derivatives have been evaluated with respect to their antimicrobial effects against such pathogenic microorganisms. Lippia sidoides Cham (Verbenaceae), popularly known as "Alecrim-pimenta" is a typical shrub commonly found in the Northeast of Brazil. Many plant species belonging to the genus Lippia yield very fragrant essential oils of potential economic value which are used by the industry for the commercial production of perfumes, creams, lotions, and deodorants. Since the leaves of L. sidoides are also extensively used in popular medicine for the treatment of skin wounds and cuts, the objective of the present study was to evaluate the composition and antimicrobial activity of L. sidoides essential oil. The essential oil was obtained by hydro-distillation and analyzed by GC-MS. Twelve compounds were characterized, having as major constituents thymol (56.7%) and carvacrol (16.7%). The antimicrobial activity of the oil and the major components was tested against cariogenic bacterial species of the genus Streptococcus as well as Candida albicans using the broth dilution and disk diffusion assays. The essential oil and its major components thymol and carvacrol exhibited potent antimicrobial activity against the organisms tested with minimum inhibitory concentrations ranging from 0.625 to 10.0 mg/mL. The most sensitive microorganisms were C. albicans and Streptococcus mutans. The essential oil of L. sidoides and its major components exert promising antimicrobial effects against oral pathogens and suggest its likely usefulness to combat oral microbial growth.

Antimicrobial efficacy of chlorhexidine digluconate alone and in combination with eucalyptus oil, tea tree oil and thymol against planktonic and biofilm cultures of Staphylococcus epidermidis.

PubMed

Karpanen, T J; Worthington, T; Hendry, E R; Conway, B R; Lambert, P A

2008-11-01

Effective skin antisepsis and disinfection of medical devices are key factors in preventing many healthcare-acquired infections associated with skin microorganisms, particularly Staphylococcus epidermidis. The aim of this study was to investigate the antimicrobial efficacy of chlorhexidine digluconate (CHG), a widely used antiseptic in clinical practice, alone and in combination with tea tree oil (TTO), eucalyptus oil (EO) and thymol against planktonic and biofilm cultures of S. epidermidis. Antimicrobial susceptibility assays against S. epidermidis in a suspension and in a biofilm mode of growth were performed with broth microdilution and ATP bioluminescence methods, respectively. Synergy of antimicrobial agents was evaluated with the chequerboard method. CHG exhibited antimicrobial activity against S. epidermidis in both suspension and biofilm (MIC 2-8 mg/L). Of the essential oils thymol exhibited the greatest antimicrobial efficacy (0.5-4 g/L) against S. epidermidis in suspension and biofilm followed by TTO (2-16 g/L) and EO (4-64 g/L). MICs of CHG and EO were reduced against S. epidermidis biofilm when in combination (MIC of 8 reduced to 0.25-1 mg/L and MIC of 32-64 reduced to 4 g/L for CHG and EO, respectively). Furthermore, the combination of EO with CHG demonstrated synergistic activity against S. epidermidis biofilm with a fractional inhibitory concentration index of <0.5. The results from this study suggest that there may be a role for essential oils, in particular EO, for improved skin antisepsis when combined with CHG.

Analysis of the essential oil components from different Carum copticum L. samples from Iran.

PubMed

Zarshenas, Mohammad M; Samani, Soliman Mohammadi; Petramfar, Peyman; Moein, Mahmoodreza

2014-01-01

The family Apiaceae is defined with the diversity of essential oil. Fruits of Ajwain (Carum copticum), a famous herb of Apiaceae, accumulate up to 5% essential oil which is remarked as important natural product for food and flavoring industry, as well as pharmacological approaches. It is believed that differences in essential oil profile in a certain plant are resulted from various cultivation situations and locations, time of cultivation and also different extracting method. Present study aimed to evaluate major components of ten different collected Ajwain samples from random cultivation locations of Iran. Samples were individually subjected to hydrodistillation using a Clevenger-type apparatus for the extraction of essential oil. GC/MS analysis for samples was carried out using Agilent technologies model 7890A gas chromatograph with a mass detector. The yield of extracted essential oil was calculated as 2.2 to 4.8% (v/w) for ten samples. Major oil components were thymol, para-cymene and gamma-terpinene. Five of ten samples have thymol as the main component with amount of 35.04 to 63.31%. On the other hand, for four samples, para-cymene was major with amount of 40.20 to 57.31% and one sample had gamma-terpinene as main constituent containing 37.43% of total oil. Accordingly, three different chemotypes, thymol, para-cymene and gamma-terpinene can be speculated from collected samples. While these components possess pharmacological effect, screening of different chemotypes not only represent the effect of cultivation situations and locations but also can be beneficial in further investigation.

Bactericidal activities of plant essential oils and some of their isolated constituents against Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, and Salmonella enterica.

PubMed

Friedman, Mendel; Henika, Philip R; Mandrell, Robert E

2002-10-01

An improved method of sample preparation was used in a microplate assay to evaluate the bactericidal activity levels of 96 essential oils and 23 oil compounds against Campylobacter jejuni, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica obtained from food and clinical sources. Bactericidal activity (BA50) was defined as the percentage of the sample in the assay mixture that resulted in a 50% decrease in CFU relative to a buffer control. Twenty-seven oils and 12 compounds were active against all four species of bacteria. The oils that were most active against C. jejuni (with BA50 values ranging from 0.003 to 0.009) were marigold, ginger root, jasmine, patchouli, gardenia, cedarwood, carrot seed, celery seed, mugwort, spikenard, and orange bitter oils; those that were most active against E. coli (with BA50 values ranging from 0.046 to 0.14) were oregano, thyme, cinnamon, palmarosa, bay leaf, clove bud, lemon grass, and allspice oils; those that were most active against L monocytogenes (with BA50 values ranging from 0.057 to 0.092) were gardenia, cedarwood, bay leaf, clove bud, oregano, cinnamon, allspice, thyme, and patchouli oils; and those that were most active against S. enterica (with BA50 values ranging from 0.045 to 0.14) were thyme, oregano, cinnamon, clove bud, allspice, bay leaf, palmarosa, and marjoram oils. The oil compounds that were most active against C. jejuni (with BA50 values ranging from 0.003 to 0.034) were cinnamaldehyde, estragole, carvacrol, benzaldehyde, citral, thymol, eugenol, perillaldehyde, carvone R, and geranyl acetate; those that were most active against E. coli (with BA50 values ranging from 0.057 to 0.28) were carvacrol, cinnamaldehyde, thymol, eugenol, salicylaldehyde, geraniol, isoeugenol, citral, perillaldehyde, and estragole; those that were most active against L monocytogenes (with BA50 values ranging from 0.019 to 0.43) were cinnamaldehyde, eugenol, thymol, carvacrol, citral, geraniol, perillaldehyde, carvone S, estragole, and salicylaldehyde; and those that were most active against S. enterica (with BA50 values ranging from 0.034 to 0.21) were thymol, cinnamaldehyde, carvacrol, eugenol, salicylaldehyde, geraniol, isoeugenol, terpineol, perillaldehyde, and estragole. The possible significance of these results with regard to food microbiology is discussed.

Antimicrobial activities of gaseous essential oils against Listeria monocytogenes on a laboratory medium and radish sprouts.

PubMed

Lee, Gyeongmin; Kim, Yoonbin; Kim, Hoikyung; Beuchat, Larry R; Ryu, Jee-Hoon

2018-01-16

The aim of this study was to evaluate the antimicrobial activities of gaseous essential oils (EO gases) against Listeria monocytogenes on the surfaces of a laboratory medium and radish sprouts. We determined the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) values of EO gases from eight EOs extracted from basil leaves, carrot seed, cinnamon bark, cinnamon leaves, clove flower buds, oregano leaves, thyme flowers (linalool), and thyme leaves (thymol) against L. monocytogenes on a nutrient agar supplemented with 1% glucose and 0.025% bromocresol purple (NGBA). Oregano, thyme thymol, and cinnamon bark EO gases showed the strongest antilisterial activities (MIC and MLC, 78.1μL/L). We also investigated the inhibitory and lethal activities of these gases against L. monocytogenes on the surface of radish sprouts. The number of L. monocytogenes after exposure to EO gases at ≥156μL/L was significantly (P≤0.05) lower than that of untreated L. monocytogenes. For example, the initial number of L. monocytogenes on the surface of radish sprouts (ca. 6.3logCFU/g) decreased by 1.4logCFU/g within 24h at 30°C and 43% relative humidity (RH) without EO gas treatment, whereas the number of L. monocytogenes after exposure to oregano, thyme thymol, and cinnamon bark EO gases at 156μL/L decreased by 2.1, 2.1, and 1.8logCFU/g, respectively, after 24h. Although EO gases exerted greater lethal activities at higher concentrations (312 and 625μL/L), L. monocytogenes on the surface of radish sprouts was not completely inactivated. The number of L. monocytogenes on sprouts treated with oregano, thyme thymol, and cinnamon bark EO gases at 625μL/L decreased by 2.7-3.0logCFU/g after 24h at 30°C and 43% RH. Results indicate that EO gases that showed antilisterial activities on a laboratory medium also exhibited reduced lethal activity on the surface of radish sprouts. These findings will be useful when developing strategies to inactivate L. monocytogenes and possibly other foodborne pathogens on sprouts and perhaps other foods using EO gases. Copyright © 2017 Elsevier B.V. All rights reserved.

[Studies on antimicrobial activity of extracts from thyme].

PubMed

Fan, M; Chen, J

2001-08-01

The extracts from thyme by water and ethanol, thyme essential oil, thymol and carvacrol were used as antimicrobial agents in this paper. The results show that all antimicrobial agents used have strong inhibition activity against Staphalococcus aureus, Bacillus subtilis, Escherichia coli.

21 CFR 582.80 - Trace minerals added to animal feeds.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Cobalt Cobalt acetate. Cobalt carbonate. Cobalt chloride. Cobalt oxide. Cobalt sulfate. Copper Copper... pyrophosphate. Copper sulfate. Iodine Calcium iodate. Calcium iodobehenate. Cuprous iodide. 3,5-Diiodosalicylic.... Thymol iodide. Iron Iron ammonium citrate. Iron carbonate. Iron chloride. Iron gluconate. Iron oxide...

21 CFR 582.80 - Trace minerals added to animal feeds.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Cobalt Cobalt acetate. Cobalt carbonate. Cobalt chloride. Cobalt oxide. Cobalt sulfate. Copper Copper... pyrophosphate. Copper sulfate. Iodine Calcium iodate. Calcium iodobehenate. Cuprous iodide. 3,5-Diiodosalicylic.... Thymol iodide. Iron Iron ammonium citrate. Iron carbonate. Iron chloride. Iron gluconate. Iron oxide...

21 CFR 582.80 - Trace minerals added to animal feeds.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Cobalt Cobalt acetate. Cobalt carbonate. Cobalt chloride. Cobalt oxide. Cobalt sulfate. Copper Copper... pyrophosphate. Copper sulfate. Iodine Calcium iodate. Calcium iodobehenate. Cuprous iodide. 3,5-Diiodosalicylic.... Thymol iodide. Iron Iron ammonium citrate. Iron carbonate. Iron chloride. Iron gluconate. Iron oxide...

Optimization of antifungal activity of Aeollanthus heliotropioides oliv essential oil and Time Kill Kinetic Assay.

PubMed

Ngo Mback, M N L; Agnaniet, H; Nguimatsia, F; Jazet Dongmo, P-M; Hzounda Fokou, J-B; Bakarnga-Via, I; Fekam Boyom, F; Menut, C

2016-09-01

The limitations encountered in the management of fungal infections are due to the resistance, high toxicity, and overuse of conventional antifungal drugs. For bringing solutions, the antifungal activity of Aeollanthus heliotropioides essential oil will be evaluated and optimized. The aerial parts of A. heliotropioides were harvested and essential oil extracted by hydrodistillation. The chemical composition was determined using gas chromatography and gas chromatography coupled with mass spectrometry and nuclear magnetic resonance. The sensitivity of fungal strains was determined using broth microdilution method. The fungicidal parameters were checked by viability assay using methylene blue dye. The Fractional Inhibitory Concentration Index was determined according the two-dimensional checkboard methods. The efficiency of the simulated optimum concentrations confirmed experimentally on American type culture collection strains, through the Time Kill Kinetic Study. The yield of extraction of essential oil was 0.1%. The major compounds were linalool (38.5%), Z-α-farnesene (25.1%), 9-hexa-decen-1-ol (13.9%) saturated/unsaturated massoia and γ-lactones (4.5%). The MIC of extract on yeast isolates ranged from 0.6mg/mL to 5mg/mL. The combination of essential oil with thymol leads mainly to synergistic effects (0.5≤FICI). The optimums of essential oil (1.6±0.4μl/mL) and thymol (0.6±0.1mg/mL) revealed a total inhibition of yeast after 120 and 180minutes according to the yeasts strains used. This study highlights the in vitro antifungal activity of A. heliotropioides essential oil and it synergistic effect with thymol. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Antimicrobial and antioxidant activity of the essential oil and methanol extracts of Thymus pectinatus Fisch. et Mey. Var. pectinatus (Lamiaceae).

PubMed

Vardar-Unlü, Gülhan; Candan, Ferda; Sökmen, Atalay; Daferera, Dimitra; Polissiou, Moschos; Sökmen, Münevver; Dönmez, Erol; Tepe, Bektaş

2003-01-01

The essential oil, obtained by using a Clevenger distillation apparatus, and water-soluble (polar) and water-insoluble (nonpolar) subfractions of the methanol extract of Thymus pectinatus Fisch. et Mey. var. pectinatus were assayed for their antimicrobial and antioxidant properties. No (or slight) antimicrobial activity was observed when the subfractions were tested, whereas the essential oil showed strong antimicrobial activity against all microorganisms tested. Antioxidant activities of the polar subfraction and the essential oil were evaluated using 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide radical scavenging, and lipid peroxidation assays. The essential oil, in particular, and the polar subfraction of the methanol extract showed antioxidant activity. The essential oil was analyzed by GC/MS, and 24 compounds, representing 99.6% of the essential oil, were identified: thymol, gamma-terpinene, p-cymene, carvacrol, and borneol were the main components. An antimicrobial activity test carried out with fractions of the essential oil showed that the activity was mainly observed in those fractions containing thymol, in particular, and carvacrol. The activity was, therefore, attributed to the presence of these compounds. Other constituents of the essential oil, such as borneol, gamma-terpinene, and p-cymene, could be also taken into account for their possible synergistic or antagonistic effects. On the other hand, thymol and carvacrol were individually found to possess weaker antioxidant activity than the crude oil itself, indicating that other constituents of the essential oil may contribute to the antioxidant activity observed. In conclusion, the results presented here show that T. pectinatus essential oil could be considered as a natural antimicrobial and antioxidant source.

Antibacterial activity and mechanism of action of Monarda punctata essential oil and its main components against common bacterial pathogens in respiratory tract.

PubMed

Li, Hong; Yang, Tian; Li, Fei-Yan; Yao, Yan; Sun, Zhong-Min

2014-01-01

The aim of the current research work was to study the chemical composition of the essential oil of Monarda punctata along with evaluating the essential oil and its major components for their antibacterial effects against some frequently encountered respiratory infection causing pathogens. Gas chromatographic mass spectrometric analysis revealed the presence of 13 chemical constituents with thymol (75.2%), p-cymene (6.7%), limonene (5.4), and carvacrol (3.5%) as the major constituents. The oil composition was dominated by the oxygenated monoterpenes. Antibacterial activity of the essential oil and its major constituents (thymol, p-cymene, limonene) was evaluated against Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Haemophilus influenzae and Escherichia coli. The study revealed that the essential oil and its constituents exhibited a broad spectrum and variable degree of antibacterial activity against different strains. Among the tested strains, Streptococcus pyogenes, Escherichia coli and Streptococcus pneumoniae were the most susceptible bacterial strain showing lowest MIC and MBC values. Methicillin-resistant Staphylococcus aureus was the most resistant bacterial strain to the essential oil treatment showing relatively higher MIC and MBC values. Scanning electron microscopy revealed that the essential oil induced potent and dose-dependent membrane damage in S. pyogenes and MRSA bacterial strains. The reactive oxygen species generated by the Monarda punctata essential oil were identified using 2', 7'-dichlorofluorescein diacetate (DCFDA).This study indicated that the Monarda punctata essential oil to a great extent and thymol to a lower extent triggered a substantial increase in the ROS levels in S. pyogenes bacterial cultures which ultimately cause membrane damage as revealed by SEM results.

Antibacterial activity and mechanism of action of Monarda punctata essential oil and its main components against common bacterial pathogens in respiratory tract

PubMed Central

Li, Hong; Yang, Tian; Li, Fei-Yan; Yao, Yan; Sun, Zhong-Min

2014-01-01

The aim of the current research work was to study the chemical composition of the essential oil of Monarda punctata along with evaluating the essential oil and its major components for their antibacterial effects against some frequently encountered respiratory infection causing pathogens. Gas chromatographic mass spectrometric analysis revealed the presence of 13 chemical constituents with thymol (75.2%), p-cymene (6.7%), limonene (5.4), and carvacrol (3.5%) as the major constituents. The oil composition was dominated by the oxygenated monoterpenes. Antibacterial activity of the essential oil and its major constituents (thymol, p-cymene, limonene) was evaluated against Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Haemophilus influenzae and Escherichia coli. The study revealed that the essential oil and its constituents exhibited a broad spectrum and variable degree of antibacterial activity against different strains. Among the tested strains, Streptococcus pyogenes, Escherichia coli and Streptococcus pneumoniae were the most susceptible bacterial strain showing lowest MIC and MBC values. Methicillin-resistant Staphylococcus aureus was the most resistant bacterial strain to the essential oil treatment showing relatively higher MIC and MBC values. Scanning electron microscopy revealed that the essential oil induced potent and dose-dependent membrane damage in S. pyogenes and MRSA bacterial strains. The reactive oxygen species generated by the Monarda punctata essential oil were identified using 2’, 7’-dichlorofluorescein diacetate (DCFDA).This study indicated that the Monarda punctata essential oil to a great extent and thymol to a lower extent triggered a substantial increase in the ROS levels in S. pyogenes bacterial cultures which ultimately cause membrane damage as revealed by SEM results. PMID:25550774

Near-infrared and Mid-infrared Spectroscopic Techniques for a Fast and Nondestructive Quality Control of Thymi herba.

PubMed

Pezzei, Cornelia K; Schönbichler, Stefan A; Hussain, Shah; Kirchler, Christian G; Huck-Pezzei, Verena A; Popp, Michael; Krolitzek, Justine; Bonn, Günther K; Huck, Christian W

2018-04-01

In this study, novel near-infrared and attenuated total reflectance mid-infrared spectroscopic methods coupled with multivariate data analysis were established enabling the determination of thymol, rosmarinic acid, and the antioxidant capacity of Thymi herba. A new high-performance liquid chromatography method and UV-Vis spectroscopy were applied as reference methods. Partial least squares regressions were carried out as cross and test set validations. To reduce systematic errors, different data pretreatments, such as multiplicative scatter correction, 1st derivative, or 2nd derivative, were applied on the spectra. The performances of the two infrared spectroscopic techniques were evaluated and compared. In general, attenuated total reflectance mid-infrared spectroscopy demonstrated a slightly better predictive power (thymol: coefficient of determination = 0.93, factors = 3, ratio of performance to deviation = 3.94; rosmarinic acid: coefficient of determination = 0.91, factors = 3, ratio of performance to deviation = 3.35, antioxidant capacity: coefficient of determination = 0.87, factors = 2, ratio of performance to deviation = 2.80; test set validation) than near-infrared spectroscopy (thymol: coefficient of determination = 0.90, factors = 6, ratio of performance to deviation = 3.10; rosmarinic acid: coefficient of determination = 0.92, factors = 6, ratio of performance to deviation = 3.61, antioxidant capacity: coefficient of determination = 0.91, factors = 6, ratio of performance to deviation = 3.42; test set validation). The capability of infrared vibrational spectroscopy as a quick and simple analytical tool to replace conventional time and chemical consuming analyses for the quality control of T. herba could be demonstrated. Georg Thieme Verlag KG Stuttgart · New York.

Bacterial susceptibility to and chemical composition of essential oils from Thymus kotschyanus and Thymus persicus.

PubMed

Rasooli, Iraj; Mirmostafa, Seyed Akbar

2003-04-09

Susceptibility of Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia, and Pseudomonas aeroginosa to the essential oils extracted from two varieties of Thyme, i.e., Thymus kotschyanus Boiss. and Hohen. and Thymus persicus L. at preflowering and flowering stages were studied. The disk diffusion method was used to evaluate the zone of microbial growth inhibition at various concentrations of the oils. Minimal inhibitory concentration and minimal bactericidal concentration of the oils were determined and compared with each other. The oils from the above plants were found to be strongly bactericidal with that of T. kotschyanus being more effective. T. kotschyanusand T. persicus oils analyzed by gas chromatography (GC) and GC/mass spectrometry (MS) lead to identification of 33 and 26 components, respectively. The profile of the oil components from T. persicuswas similar to that of T. kotschyanus in almost all of the compounds but at different concentrations. The major components of T. kotschyanus oil before and at the flowering stages were carvacrol (35.06, 22.75%), thymol (26.60, 16.52%), gamma-terpinene (7.81, 0.34%), gamma-terpinene (4.34, 0%), borneol (2.29, 4.52%), myrcene (0.26, 12.65%), thymolquinone (0, 11.39%), nerol (0, 6.10%), and beta-caryophyllene (0, 5.54%), respectively, and those of T. persicus at the same stages were carvacrol (38.96, 27.07%), thymol (6.48, 11.86%), P-cymene (7.51, 10.16%), gamma-terpineol (0, 9.51%), nerol (15.66, 9.41%), gamma-terpinene (6.11, 6.51%), and thymol acetate (5.29, 5.30%), respectively. The contribution of oil components to its antibacterial property is discussed. High aromatic compound content of the phenol-rich oils seems to account for strong antibacterial activity.

Green drugs in the fight against Anisakis simplex-larvicidal activity and acetylcholinesterase inhibition of Origanum compactum essential oil.

PubMed

López, Víctor; Cascella, María; Benelli, Giovanni; Maggi, Filippo; Gómez-Rincón, Carlota

2018-03-01

Anisakiasis is a fish-borne parasitic disease caused by the consumption of raw or undercooked fish, as well as cephalopods, contaminated by third instar larvae (L3) of species belonging to the genus Anisakis (Anisakidae). Origanum compactum is a small herbaceous aromatic plant endemic to Spain and Morocco. In Morocco, the plant is used under infusion to treat heart diseases and intestinal pains or as preservative for foodstuffs. This is the first time that the O. compactum essential oil is tested against the parasitic nematode Anisakis simplex. The phytochemical analysis by GC-MS revealed carvacrol (50.3%) and thymol (14.8%) as the major oil constituents. The essential oil and its major constituents carvacrol and thymol were tested against A. simplex L3 larvae isolated from blue whiting fish (Micromesistius poutassou). A. simplex mortality (%) after 24 and 48 h of treatment at 1 μl/ml was 100%, with a low LD 50 compared with other essential oils and extracts, and the penetration in the agar assay was also reduced, if compared with control wells. The oil, as well as its major constituents, demonstrated a dose-dependent larvicidal activity. Inhibition of the enzyme acetylcholinesterase through a colorimetric assay in 96-well plates was used to elucidate the pharmacological mechanism as this enzyme plays a key role in nematodes neuromuscular function. Interestingly, O. compactum essential oil, carvacrol and thymol inhibited the enzyme, confirming that this could be one of the mechanisms involved in the anthelmintic activity. To the best of our knowledge, this is the first time that O. compactum essential oil is reported as a larvicidal agent against A. simplex L3 larvae.

Tyrosinase inhibitory activity, molecular docking studies and antioxidant potential of chemotypes of Lippia origanoides (Verbenaceae) essential oils.

PubMed

da Silva, Alessandra P; Silva, Natália de F; Andrade, Eloísa Helena A; Gratieri, Tais; Setzer, William N; Maia, José Guilherme S; da Silva, Joyce Kelly R

2017-01-01

The essential oils (EOs) of the aerial parts of Lippia origanoides (LiOr), collected in different localities of the Amazon region, were obtained by hydrodistillation and analyzed by GC and CG-MS. Principle component analysis (PCA) based on chemical composition grouped the oils in four chemotypes rich in mono- and sesquiterpenoids. Group I was characterized by 1,8-cineole and α-terpineol (LiOr-1 and LiOr-4) and group II by thymol (LiOr-2). The oil LiOr-3 showed β-caryophyllene, α-phellandrene and β-phellandrene as predominant and LiOr-5 was rich in (E)-nerolidol and β-caryophyllene. All samples were evaluated for antioxidant activity and inhibition of tyrosinase in vitro and in silico. The highest antioxidant activity by the DPPH free radical method was observed in LiOr-2 and LiOr-5 oils (132.1 and 82.7 mg TE∙mL-1, respectively). The tyrosinase inhibition potential was performed using L-tyrosine and L-DOPA as substrates and all samples were more effective in the first step of oxidation. The inhibition by samples LiOr-2 and LiOr-4 were 84.7% and 62.6%, respectively. The samples LiOr-1, LiOr-4 and LiOr-5 displayed an interaction with copper (II) ion with bathochromic shift around 15 nm. In order to elucidate the mechanism of inhibition of the main compounds, a molecular docking study was carried out. All compounds displayed an interaction between an oxygen and Cu or histidine residues with distances less than 4 Å. The best docking energies were observed with thymol and (E)-nerolidol (-79.8 kcal.mol-1), which suggested H-bonding interactions with Met281 and His263 (thymol) and His259, His263 ((E)-nerolidol).

Antifungal activity of synthetic antiseptics and natural compounds against Candida dubliniensis before and after in vitro fluconazole exposure.

PubMed

Reginato, Cássia Franco; Bandeira, Laíssa Arévalo; Zanette, Régis Adriel; Santurio, Janio Morais; Alves, Sydney Hartz; Danesi, Cristiane Cademartori

2017-01-01

This study evaluated the susceptibilities of oral candidiasis-derived Candida albicans, fluconazole-resistant (FR) Candida dubliniensis, and fluconazole-susceptible (FS) C. dubliniensis to synthetic antiseptics [chlorhexidine gluconate (CHX), cetylpyridinium chloride (CPC), and triclosan (TRC)] and natural compounds (carvacrol, eugenol and thymol). Susceptibility tests were performed based on the M27-A3 reference method. The fluconazole-resistant C. dubliniensis strains were obtained after prolonged in vitro exposure to increasing fluconazole concentrations. The geometric mean values for minimum inhibitory concentrations and minimum fungicidal concentrations were compared among the groups. Fluconazole-susceptible C. dubliniensis was more sensitive to CPC and TRC than FR C. dubliniensis and C. albicans were. However, eugenol and thymol were more active against FR C. dubliniensis. The fungicidal activities of CHX and TRC were similar for the three groups, and FR C. dubliniensis and C. albicans had similar sensitivities to CPC. The resistance of C. dubliniensis to fluconazole affects its sensitivity the synthetic antiseptics and natural compounds that were tested.

Nanoemulsions of thymol and eugenol co-emulsified by lauric arginate and lecithin.

PubMed

Ma, Qiumin; Davidson, P Michael; Zhong, Qixin

2016-09-01

Lauric arginate (LAE) is a cationic surfactant with excellent antimicrobial activities. To incorporate essential oil components (EOCs) in aqueous systems, properties of EOC nanoemulsions prepared with a LAE and lecithin mixture were studied. The LAE-lecithin mixture resulted in stable translucent nanoemulsions of thymol and eugenol with spherical droplets smaller than 100nm, contrasting with the turbid emulsions prepared with individual emulsifiers. Zeta-potential data suggested the formation of LAE-lecithin complexes probably through hydrophobic interaction. Negligible difference was observed for antimicrobial activities of nanoemulsions and LAE in tryptic soy broth. In 2% reduced fat milk, nanoemulsions showed similar antilisterial activities compared to free LAE in inhibiting Listeria monocytogenes, but was less effective against Escherichia coli O157:H7 than free LAE, which was correlated with the availability of LAE as observed in release kinetics. Therefore, mixing LAE with lecithin improved the physical properties of EOC nanoemulsions but did not improve antimicrobial activities, especially against Gram-negative bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative investigation of Umbellularia californica and Laurus nobilis leaf essential oils and identification of constituents active against Aedes aegypti.

PubMed

Tabanca, Nurhayat; Avonto, Cristina; Wang, Mei; Parcher, Jon F; Ali, Abbas; Demirci, Betul; Raman, Vijayasankar; Khan, Ikhlas A

2013-12-18

Umbellularia californica (California bay laurel) and Laurus nobilis (Mediterranean bay laurel) leaves may be mistaken or used as a substitute on the market due to their morphological similarity. In this study, a comparison of anatomical and chemical features and biological activity of both plants is presented. L. nobilis essential oil biting deterrent and larvicidal activity were negligible. On the other hand, U. californica leaf oil showed biting deterrent activity against Aedes aegypti . The identified active repellents was thymol, along with (-)-umbellulone, 1,8-cineole, and (-)-α-terpineol. U. californica essential oil also demonstrated good larvicidal activity against 1-day-old Ae. aegypti larvae with a LD50 value of 52.6 ppm. Thymol (LD50 = 17.6 ppm), p-cymene, (-)-umbellulone, and methyleugenol were the primary larvicidal in this oil. Umbellulone was found as the principal compound (37%) of U. californica essential oil, but was not present in L. nobilis essential oil. Umbellulone mosquito activity is here reported for the first time.

Use of natural compounds to improve the microbial stability of Amaranth-based homemade fresh pasta.

PubMed

Del Nobile, M A; Di Benedetto, N; Suriano, N; Conte, A; Lamacchia, C; Corbo, M R; Sinigaglia, M

2009-04-01

A study on the use of natural antimicrobial compounds to improve the microbiological stability of refrigerated amaranth-based homemade fresh pasta is presented in this work. In particular, the antimicrobial activity of thymol, lemon extract, chitosan and grapefruit seed extract (GFSE) has been tested against mesophilic and psychrotrophic bacteria, total coliforms, Staphylococcus spp., yeasts and moulds. A sensory analysis on both fresh and cooked pasta was also run. Results suggest that chitosan and GFSE strongly increase the microbial acceptability limit of the investigated spoilage microorganisms, being the former the most effective. Thymol efficiently reduces the growth of mesophilic bacteria, psychrotrophic bacteria and Staphylococcus spp., whereas it does not affect, substantially, the growth cycle of total coliforms. Lemon extract is the less effective in preventing microbial growth. In fact, it is able to delay only total mesophilic and psychrotrophic bacterial evolution. From a sensorial point of view no significant differences were recorded between the control samples and all the types of loaded amaranth-based pasta.

The preservation of urine samples for determination of renal stone risk factors

NASA Technical Reports Server (NTRS)

Nicar, M. J.; Hsu, M. C.; Johnson, T.; Pak, C. Y.

1987-01-01

A preservation technique for urine specimens before determination of stone risk factors was evaluated. The purpose of these experiments was to prove the effectiveness of the preservatives used to prevent changes in the concentrations of those constituents measured. Measured concentrations in fresh specimens were compared with those in the same specimens after storage with the preservatives. Refrigeration at 4 degrees C up to five days was appropriate in a laboratory setting, as no significant changes in urinary concentrations occurred. Refrigeration, however, did not offer a convenient method for shipping. Chemical preservation was found to be an effective alternative to refrigeration. Thymol prevented changes in concentration of pH, citrate, uric acid, sulfate, sodium, potassium, and cyclic AMP, while a mixture of hydrochloric (HCl) acid and boric acid prevented changes in calcium, magnesium, phosphorus, oxalate, ammonium, and creatinine. Thus, the addition of thymol or HCl/boric acid to urine specimens will prevent significant changes in the concentrations of stone risk factors.

Development and characterization of novel antimicrobial bilayer films based on Polylactic acid (PLA)/Pickering emulsions.

PubMed

Zhu, Jun-You; Tang, Chuan-He; Yin, Shou-Wei; Yang, Xiao-Quan

2018-02-01

Biodegradable food packaging is sustainable and has a great application prospect. PLA is a promising alternative for petroleum-derived polymers. However, PLA packaging suffers from poor barrier properties compared with petroleum-derived ones. To address this issue, we designed bilayer films based on PLA and Pickering emulsions. The formed bilayer films were compact and uniform and double layers were combined firmly. This strategy enhanced mechanical resistance, ductility and moisture barrier of Pickering emulsion films, and concomitantly enhanced the oxygen barrier for PLA films. Thymol loadings in Pickering emulsion layer endowed them with antimicrobial and antioxidant activity. The release profile of thymol was well fitted with Fick's second law. The antimicrobial activity of the films depended on film types, and Pickering emulsion layer presented larger inhibition zone than PLA layer, hinting that the films possessed directional releasing role. This study opens a promising route to fabricate bilayer architecture creating synergism of each layer. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Essential Oil from Origanum vulgare L. and Its Individual Constituents Carvacrol and Thymol Enhance the Effect of Tetracycline against Staphylococcus aureus.

PubMed

Cirino, Isis Caroline S; Menezes-Silva, Suellen Maria P; Silva, Helena Tainá D; de Souza, Evandro Leite; Siqueira-Júnior, José P

2014-01-01

In an ongoing project to evaluate essential oils as modulators of antibiotic resistance, the essential oil from Origanum vulgare L. (OVEO), as well as its individual constituents carvacrol (CAR) and thymol (THY), were investigated using Staphylococcus aureus strains possessing efflux mechanisms of resistance to norfloxacin, erythromycin and tetracycline. The minimum inhibitory concentration (MIC) values of the antibiotics were determined by agar dilution method, in the absence and in the presence of subinhibitory concentrations of OVEO, CAR or THY. Along with relevant antistaphylococcal activity, OVEO, CAR and THY modulated the activity of tetracycline, i.e. in combination with antibiotics a reduction in the MIC was observed (up to fourfold). The results presented here represent, as far as we know, the first report of OVEO, CAR and THY as putative efflux pump inhibitors. Broadly, these findings indicate that essential oils could serve as potential sources of compounds capable of modulating drug resistance. © 2015 S. Karger AG, Basel.

Chemical composition and antimicrobial activity of the essential oil of Tanacetum walteri (Anthemideae-Asteraceae) from Iran.

PubMed

Ghaderi, Airin; Sonboli, Ali

2018-02-06

The composition and antimicrobial activity of the essential oil of Tanacetum walteri were studied. Aerial flowering parts of plant were collected from North Khorasan Province of Iran and the essential oil was isolated by hydrodistillation and analysed by GC-FID and GC-MS. Antimicrobial activity of the essential oil was determined by disc diffusion and MIC and MBC determination. Thirty-five compounds were identified in the oil of T. walteri accounting for 94.4% of the total oil. Thymol (22.5%), 1,8-cineole (8.2%), umbellulone (6.9%), α-bisabolol (6.3%) and camphor (5.3%) were as the principal constituents. The highest antimicrobial activity of the essential oil was observed against Staphylococcus aureus, Enterococcus faecalis and Klebsiella pneumoniae with MIC value of 0.63 mg/mL. The inhibitory effect of the essential oil of T. walteri could be attributed mainly to the high levels of phenolic compound thymol and oxygenated terpenes in essential oil.

Carbon dioxide gas sensor based on optical control of color in liquid indicator

NASA Astrophysics Data System (ADS)

Oblov, K. Yu; Ivanova, A. V.; Soloviev, S. A.; Zhdanov, S. V.; Voronov, Yu A.; Florentsev, V. V.

2016-10-01

A new optical carbon dioxide sensor based on the change in glow intensity of the Europium-III complex, caused by CO2 absorption to various pH-indicators (thymol blue, phenol red and cresol red) of carbon dioxide was developed, and its sensitive properties were studied.

Ethanol-Glycerin Fixation with Thymol Conservation: A Potential Alternative to Formaldehyde and Phenol Embalming

ERIC Educational Resources Information Center

Hammer, Niels; Loffler, Sabine; Feja, Christine; Sandrock, Mara; Schmidt, Wolfgang; Bechmann, Ingo; Steinke, Hanno

2012-01-01

Anatomical fixation and conservation are required to prevent specimens from undergoing autolysis and decomposition. While fixation is the primary arrest of the structures responsible for autolysis and decomposition, conservation preserves the state of fixation. Although commonly used, formaldehyde has been classified as carcinogenic to humans. For…

Evaluation of essential oils in beef cattle manure slurries and applications of select compounds to beef feedlot surfaces to control zoonotic pathogens

USDA-ARS?s Scientific Manuscript database

Aims: To evaluate natural terpene compounds for antimicrobial activities and determine if these compounds could be used to control microbial activities and pathogens in production animal facilities. Methods and Results: Thymol, geraniol, glydox, linalool, pine oil, plinol, and terpineol were teste...

Augmenting the activity of monoterpenoid phenols against fungal pathogens using 2-hydroxy-4-methoxybenzaldehyde that target cell wall integrity

USDA-ARS?s Scientific Manuscript database

The aim of this study was to identify benzaldehydes to which the fungal cell wall integrity signaling mutants showed increased sensitivity. These compounds could then function as chemosensitizing agents in combination with monoterpenoid phenols, such as carvacrol or thymol, to enhance antifungal act...

Bioassay-guided investigation of two Monarda essential oils as repellents of yellow fever mosquito Aedes aegypti.

PubMed

Tabanca, Nurhayat; Bernier, Ulrich R; Ali, Abbas; Wang, Mei; Demirci, Betul; Blythe, Eugene K; Khan, Shabana I; Baser, K Husnu Can; Khan, Ikhlas A

2013-09-11

As part of an ongoing research program to identify active mosquito repellents, Monarda bradburiana Beck and Monarda fistulosa L. essential oils showed good repellent activity with minimum effective dosages (MED) of 0.055 ± 0.036 and 0.078 ± 0.027 mg/cm(2), respectively, compared to reference standard N,N-diethyl-3-methylbenzamide (DEET) (0.039 ± 0.014 mg/cm(2)). Systematic bioassay-guided fractionation of essential oils of both Monarda species was performed to identify the active repellent compounds, and isolated pure compounds were individually tested for repellency. Of the isolated compounds, carvacrol, thymol, eugenol, and carvacrol methyl ether were found to be the repellent compounds with MEDs in the range of 0.013-0.063 mg/cm(2). Active repellent compounds were also tested for larvicidal activity against 1-day-old Aedes aegypti larvae. Thymol was the best larvicide among the tested individual compounds (LD50 of 13.9 ppm). None of the individual compounds showed cytotoxicity against mammalian cells; however, the essential oils were toxic to all cell lines.

Clove and rosemary essential oils and encapsuled active principles (eugenol, thymol and vanillin blend) on meat quality of feedlot-finished heifers.

PubMed

de Oliveira Monteschio, Jéssica; de Souza, Kennyson Alves; Vital, Ana Carolina Pelaes; Guerrero, Ana; Valero, Maribel Velandia; Kempinski, Emília Maria Barbosa Carvalho; Barcelos, Vinícius Cunha; Nascimento, Karina Favoreto; do Prado, Ivanor Nunes

2017-08-01

Forty Nellore heifers were fed (73days) with different diets: with or without essential oils (clove and/or rosemary essential oil) and/or active principle blend (eugenol, thymol and vanillin). The pH, fat thickness, marbling, muscle area and water losses (thawing and drip) were evaluated 24h post mortem on the Longissimus thoracis, and the effects of aging (14days) was evaluated on the meat cooking losses, color, texture and lipid oxidation. Antioxidant activity was also evaluated. Treatments had no effect (P>0.05) on pH, fat thickness, marbling, muscle area, thawing and drip losses. However, treatments affected (P<0.05) cooking losses, color, texture and lipid oxidation. The diets with essential oil and the active principle blend reduced the lipid oxidation and reduced the color losses in relation to control diet. Aging affected (P<0.05) texture and lipid oxidation. The essential oil and active principles or its blend have potential use in animal feed aiming to maintain/improve meat quality during shelf-life. Copyright © 2017. Published by Elsevier Ltd.

Effect of Various Compounds Blocking the Colony Pigmentation on the Aflatoxin B1 Production by Aspergillus flavus.

PubMed

Dzhavakhiya, Vitaly G; Voinova, Tatiana M; Popletaeva, Sofya B; Statsyuk, Natalia V; Limantseva, Lyudmila A; Shcherbakova, Larisa A

2016-10-28

Aflatoxins and melanins are the products of a polyketide biosynthesis. In this study, the search of potential inhibitors of the aflatoxin B1 (AFB1) biosynthesis was performed among compounds blocking the pigmentation in fungi. Four compounds-three natural (thymol, 3-hydroxybenzaldehyde, compactin) and one synthetic (fluconazole)-were examined for their ability to block the pigmentation and AFB1 production in Aspergillus flavus . All compounds inhibited the mycelium pigmentation of a fungus growing on solid medium. At the same time, thymol, fluconazole, and 3-hydroxybenzaldehyde stimulated AFB1 accumulation in culture broth of A. flavus under submerged fermentation, whereas the addition of 2.5 μg/mL of compactin resulted in a 50× reduction in AFB1 production. Moreover, compactin also suppressed the sporulation of A. flavus on solid medium. In vivo treatment of corn and wheat grain with compactin (50 μg/g of grain) reduced the level of AFB1 accumulation 14 and 15 times, respectively. Further prospects of the compactin study as potential AFB1 inhibitor are discussed.

Tyrosinase inhibitory activity, molecular docking studies and antioxidant potential of chemotypes of Lippia origanoides (Verbenaceae) essential oils

PubMed Central

Silva, Natália de F.; Andrade, Eloísa Helena A.; Gratieri, Tais; Setzer, William N.; Maia, José Guilherme S.

2017-01-01

The essential oils (EOs) of the aerial parts of Lippia origanoides (LiOr), collected in different localities of the Amazon region, were obtained by hydrodistillation and analyzed by GC and CG-MS. Principle component analysis (PCA) based on chemical composition grouped the oils in four chemotypes rich in mono- and sesquiterpenoids. Group I was characterized by 1,8-cineole and α-terpineol (LiOr-1 and LiOr-4) and group II by thymol (LiOr-2). The oil LiOr-3 showed β-caryophyllene, α-phellandrene and β-phellandrene as predominant and LiOr-5 was rich in (E)-nerolidol and β-caryophyllene. All samples were evaluated for antioxidant activity and inhibition of tyrosinase in vitro and in silico. The highest antioxidant activity by the DPPH free radical method was observed in LiOr-2 and LiOr-5 oils (132.1 and 82.7 mg TE∙mL-1, respectively). The tyrosinase inhibition potential was performed using L-tyrosine and L-DOPA as substrates and all samples were more effective in the first step of oxidation. The inhibition by samples LiOr-2 and LiOr-4 were 84.7% and 62.6%, respectively. The samples LiOr-1, LiOr-4 and LiOr-5 displayed an interaction with copper (II) ion with bathochromic shift around 15 nm. In order to elucidate the mechanism of inhibition of the main compounds, a molecular docking study was carried out. All compounds displayed an interaction between an oxygen and Cu or histidine residues with distances less than 4 Å. The best docking energies were observed with thymol and (E)-nerolidol (-79.8 kcal.mol-1), which suggested H-bonding interactions with Met281 and His263 (thymol) and His259, His263 ((E)-nerolidol). PMID:28459864

Thymol-based sub-micron emulsions exhibit antifungal activity against Fusarium graminearum and inhibit Fusarium head blight (FHB) in wheat

USDA-ARS?s Scientific Manuscript database

Fusarium graminearum is a very destructive fungal pathogen that leads to Fusarium head blight (FHB) in wheat, a disease that costs growers millions of dollars annually both in crop losses and control measures. Current countermeasures include the deployment of wheat varieties with some resistance to ...

27 CFR 21.65 - Formula No. 38-B.

Code of Federal Regulations, 2012 CFR

2012-04-01

.... Cinnamic aldehyde, N.F. IX. Cinnamon oil, N.F. Citronella oil, natural. Clove oil, N.F. Coal tar, U.S.P..., terpeneless. Spike lavender oil, natural. Storax, U.S.P. Thyme oil, N.F. XII. Thymol, N.F. Tolu balsam, U.S.P... the denaturant for analysis. (b) Authorized uses. (1) As a solvent: 111.Hair and scalp preparations...

27 CFR 21.65 - Formula No. 38-B.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Cinnamic aldehyde, N.F. IX. Cinnamon oil, N.F. Citronella oil, natural. Clove oil, N.F. Coal tar, U.S.P..., terpeneless. Spike lavender oil, natural. Storax, U.S.P. Thyme oil, N.F. XII. Thymol, N.F. Tolu balsam, U.S.P... the denaturant for analysis. (b) Authorized uses. (1) As a solvent: 111.Hair and scalp preparations...

27 CFR 21.65 - Formula No. 38-B.

Code of Federal Regulations, 2013 CFR

2013-04-01

.... Cinnamic aldehyde, N.F. IX. Cinnamon oil, N.F. Citronella oil, natural. Clove oil, N.F. Coal tar, U.S.P..., terpeneless. Spike lavender oil, natural. Storax, U.S.P. Thyme oil, N.F. XII. Thymol, N.F. Tolu balsam, U.S.P... the denaturant for analysis. (b) Authorized uses. (1) As a solvent: 111.Hair and scalp preparations...

27 CFR 21.65 - Formula No. 38-B.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... Cinnamic aldehyde, N.F. IX. Cinnamon oil, N.F. Citronella oil, natural. Clove oil, N.F. Coal tar, U.S.P..., terpeneless. Spike lavender oil, natural. Storax, U.S.P. Thyme oil, N.F. XII. Thymol, N.F. Tolu balsam, U.S.P... the denaturant for analysis. (b) Authorized uses. (1) As a solvent: 111.Hair and scalp preparations...

27 CFR 21.65 - Formula No. 38-B.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Cinnamic aldehyde, N.F. IX. Cinnamon oil, N.F. Citronella oil, natural. Clove oil, N.F. Coal tar, U.S.P..., terpeneless. Spike lavender oil, natural. Storax, U.S.P. Thyme oil, N.F. XII. Thymol, N.F. Tolu balsam, U.S.P... the denaturant for analysis. (b) Authorized uses. (1) As a solvent: 111.Hair and scalp preparations...

Acaricidal efficacies of Lippia gracilis essential oil and its phytochemicals against organophosphate-resistant and susceptible strains of Rhipicephalus (Boophilus) microplus

USDA-ARS?s Scientific Manuscript database

Plant-derived natural products can serve as an alternative to synthetic compounds for control of ticks of veterinary and medical importance. Lippia gracilis is an aromatic plant that produces essential oil with high content of carvacrol and thymol monoterpenes. These monoterpenes have high acaricida...

Bio-based phenolic-branched-chain fatty acid isomers synthesized from vegetable oils and natural monophenols using modified h+-ferrierite zeolite

USDA-ARS?s Scientific Manuscript database

A new group of phenolic branched-chain fatty acids (n-PBC-FA), hybrid molecules of natural monophenols (i.e., thymol, carvacrol and creosote) and mixed fatty acid (i.e., derived from soybean and safflower oils), were efficiently produced through a process known as arylation. The reaction involves a...

Study on the synergic effect of natural compounds on the microbial quality decay of packed fish hamburger.

PubMed

Corbo, M R; Speranza, B; Filippone, A; Granatiero, S; Conte, A; Sinigaglia, M; Del Nobile, M A

2008-10-31

The effectiveness of natural compounds in slowing down the microbial quality decay of refrigerated fish hamburger is addressed in this study. In particular, the control of the microbiological spoilage by combined use of three antimicrobials, and the determination of their optimal composition to extend the fish hamburger Microbiological Stability Limit (MAL) are the main objectives of this work. Thymol, grapefruit seed extract (GFSE) and lemon extract were tested for monitoring the cell growth of the main fish spoilage microorganisms (Pseudomonas fluorescens, Photobacterium phosphoreum and Shewanella putrefaciens), inoculated in fish hamburgers, and the growth of mesophilic and psychrotrophic bacteria. A Central Composite Design (CCD) was developed to highlight a possible synergic effect of the above natural compounds. Results showed an increase in the MAL value for hamburgers mixed with the antimicrobial compounds, compared to the control sample. The optimal antimicrobial compound composition, which corresponds to the maximal MAL value determined in this study, is: 110 mgL(-1) of thymol, 100 mgL(-1) of GFSE and 120 mgL(-1) of lemon extract. The presence of the natural compounds delay the sensorial quality decay without compromising the flavor of the fish hamburgers.

The synergistic effects of insecticidal essential oils and piperonyl butoxide on biotransformational enzyme activities in Aedes aegypti (Diptera: Culicidae).

PubMed

Waliwitiya, Ranil; Nicholson, Russell A; Kennedy, Christopher J; Lowenberger, Carl A

2012-05-01

The biochemical mechanisms underlying the increased toxicity of several plant essential oils (thymol, eugenol, pulegone, terpineol, and citronellal) against fourth instar of Aedes aegypti L. when exposed simultaneously with piperonyl butoxide (PBO) were examined. Whole body biotransformational enzyme activities including cytochrome P450-mediated oxidation (ethoxyresorufin O-dethylase [EROD]), glutathione S-transferase (GST), and beta-esterase activity were measured in control, essential oil-exposed only (single chemical), and essential oil + PBO (10 mg/liter) exposed larvae. At high concentrations, thymol, eugenol, pulegone, and citronellal alone reduced EROD activity by 5-25% 16 h postexposure. Terpineol at 10 mg/liter increased EROD activity by 5 +/- 1.8% over controls. The essential oils alone reduced GST activity by 3-20% but PBO exposure alone did not significantly affect the activity of any of the measured enzymes. All essential oils in combination with PBO reduced EROD activity by 58-76% and reduced GST activity by 3-85% at 16 h postexposure. This study indicates a synergistic interaction between essential oils and PBO in inhibiting the cytochrome P450 and GST detoxification enzymes in Ae. aegypti.

Antimicrobial and antioxidant activities and chemical characterization of essential oils of Thymusvulgaris, Rosmarinus officinalis, and Origanum majorana from northeastern México.

PubMed

Guerra-Boone, Laura; Alvarez-Román, Rocío; Alvarez-Román, Rocío; Salazar-Aranda, Ricardo; Torres-Cirio, Anabel; Rivas-Galindo, Verónica Mayela; de-Torres, Noemí Waksman; González, Gloria; Pérez-López, Luis Alejandro

2015-01-01

There have been no reports of antifungal activity and composition of extracts from Thymus vulgaris, Rosmarinus officinalis or Origanum majorana from northeastern México. Antifungal activity of these oils against Trichophyton rubrum, Trichophyton tonsurans, Trichophyton mentagrophytes, Microsporum gypseum, Microsporum canis and Epidermophyton floccosum was measured by diffusion assay. Additionally, antibacterial and antioxidant activities were evaluated. Antibacterial activity against Staphylococcus aureus and Streptococcus pyogenes was examined by microdilution. Antioxidant activity was assessed by 2,2-difenil-1-picrilhidracil reduction test. The plant oils were characterized by both GC/MS and GC/FID. Oils of T. vulgaris and O. majorana showed growth inhibition activity against dermatophytes, especially T. vulgaris oil, which completely inhibited growth of all tested dermatophytes. The oils also showed bioactivity against bacteria, with minimum inhibitory concentration (MIC) values between 62.5 and 500 μg/mL. The antioxidant activity of the oils was low, with effective concentration (EC50) values <250μg/mL. The major components in the oils were as follows: T. vulgaris, o-cymene, μ-terpinene, thymol and carvacrol; R. officinalis, terpinen-4-ol and 1,8-cineole; O. majorana, terpinen-4-ol and thymol.

Chemical composition and assessment of larvicidal and repellent capacity of 14 Lamiaceae essential oils against Aedes albopictus.

PubMed

Giatropoulos, Athanassios; Kimbaris, Athanasios; Michaelakis, Αntonios; Papachristos, Dimitrios P; Polissiou, Moschos G; Emmanouel, Nickolaos

2018-06-01

In the current laboratory study, 14 essential oils (EOs) derived from 12 Lamiaceae plant species and their major components were screened for their larvicidal and repellent properties against Aedes albopictus, an invasive mosquito species of great medical importance. The results of toxicity bioassays revealed that the EOs from Thymus vulgaris, Ocimum basilicum, Origanum dictamnus, Origanum majorana, and Origanum vulgare, as well as their major components (terpenes), namely thymol, carvacrol, p-cymene, and γ-terpinene exerted the highest larvicidal effect. Essential oils from Mellisa officinalis, Origanum dictamus, Mentha spicata (chem. piperitenone epoxide), Origanum majorana, and Satureja thymbra were the most potent repellents, with the last two assigned as the best ones. Among the terpenes tested, piperitenone epoxide, carvacrol, thymol, and piperitenone provided the highest level of protection against Ae. albopictus adults. Chemical analysis revealed the presence of a high number of terpenes in the EOs, while in most cases, the biological action of the tested EOs and their major components was in consistency. The most effective EOs and terpenes that were identified through the current laboratory bioassays could be used as alternative agents to control larvae and repel adults of Ae. albopictus.

Teriyaki sauce with carvacrol or thymol effectively controls Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and indigenous flora in marinated beef and marinade.

PubMed

Moon, Hyeree; Kim, Nam Hee; Kim, Soon Han; Kim, Younghoon; Ryu, Jee Hoon; Rhee, Min Suk

2017-07-01

An effective bactericidal cold-marinating method for beef products is described, exploiting the synergism between soy sauce and natural compounds (carvacrol, CV or thymol, TM) to reduce microbiological risks. Beef slices inoculated with Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium (3.1-3.5logCFU/g) were marinated in a teriyaki sauce with or without CV and TM (0.3 and 0.5%). After 1, 3, and 7days at 4°C, indigenous microflora population, color, lipid oxidation, marinade uptake, and pH of marinated beef and leftover marinade samples were examined. Teriyaki sauce alone did not reduce or inhibit any of the target pathogens or indigenous bacteria, while 0.5% CV- or TM-containing teriyaki sauce inactivated all inocula without recovery within 7days (p<0.05). The pathogens relocated from the beef into the leftover marinade (3.0-3.4logCFU/mL) were also completely inactivated. The treatment inhibited growth of indigenous aerobic bacteria (p<0.05) and inactivated coliform bacteria. Physicochemical parameters were not significantly affected (p>0.05). Copyright © 2017 Elsevier Ltd. All rights reserved.

Antibacterial potential of phytochemicals alone or in combination with antimicrobials against fish pathogenic bacteria.

PubMed

Bandeira Junior, G; Sutili, F J; Gressler, L T; Ely, V L; Silveira, B P; Tasca, C; Reghelin, M; Matter, L B; Vargas, A P C; Baldisserotto, B

2018-05-09

This study investigated the antibacterial activity of five phytochemicals (carvacrol, citral, eugenol, linalool, and thymol) alone or in combination with florfenicol or oxytetracycline against bacteria isolated from silver catfish (Rhamdia quelen). We also analyzed the potential of these compounds to inhibit biofilm formation and hemolysis caused by the bacteria. Bacteria were tested with antimicrobials to calculate the multiple antibiotic resistance (MAR). The checkerboard assay was used to evaluate a putative synergy between five phytochemicals and antimicrobials against the strains isolated. The biofilm formation inhibition assay was performed with phytochemicals and antimicrobials, and the hemolysis inhibition assay was performed with the phytochemicals. Carvacrol, eugenol and thymol were the most effective phytochemicals. Three combinations (linalool with florfenicol or oxytetracycline against Aeromonas hydrophila and citral with oxytetracycline against Citrobacter freundii) demonstrated synergy in the checkerboard assay. All phytochemicals inhibited biofilm formation and hemolysis activity. The tested phytochemicals showed satisfactory activity against fish pathogenic bacteria. The phytochemicals did not present antagonistic interactions with the antimicrobials, allowing their combined use, which may contribute to a decrease in the use of conventional drugs and their residues in aquatic environment. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Microencapsulated sorbic acid and pure botanicals affect Salmonella Typhimurium shedding in pigs: a close-up look from weaning to slaughter in controlled and field conditions

USDA-ARS?s Scientific Manuscript database

The aim of this study was to assess the efficacy of a combination of sorbic acid, thymol, and carvacrol in reducing the prevalence and shedding of Salmonella Typhimurium in pigs either in a controlled challenge environment or in a production setting. In the first study, 24 weaned piglets were dist...

Modeling the inactivation of Escherichia coli 0157:H7 and uropathogenic E.coli in ground chicken by high pressure processing and thymol

USDA-ARS?s Scientific Manuscript database

Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compare the resistance of iPEC (O157:H7) to UPEC in chicken meat using High Pressure Processing...

27 CFR 21.68 - Formula No. 38-F.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Six pounds of either boric acid, N.F., or Polysorbate 80, N.F.; 11/3 pounds of thymol, N.F.; 11/3... of any two or more denaturing materials listed under Formula No. 38-B, plus sufficient boric acid, N..., U.S.P., 2.6 fluid ounces of hydrochloric acid, N.F., and a total of 3 pounds of any two or more of...

27 CFR 21.68 - Formula No. 38-F.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Six pounds of either boric acid, N.F., or Polysorbate 80, N.F.; 11/3 pounds of thymol, N.F.; 11/3... of any two or more denaturing materials listed under Formula No. 38-B, plus sufficient boric acid, N..., U.S.P., 2.6 fluid ounces of hydrochloric acid, N.F., and a total of 3 pounds of any two or more of...

27 CFR 21.68 - Formula No. 38-F.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Six pounds of either boric acid, N.F., or Polysorbate 80, N.F.; 11/3 pounds of thymol, N.F.; 11/3... of any two or more denaturing materials listed under Formula No. 38-B, plus sufficient boric acid, N..., U.S.P., 2.6 fluid ounces of hydrochloric acid, N.F., and a total of 3 pounds of any two or more of...

27 CFR 21.68 - Formula No. 38-F.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Six pounds of either boric acid, N.F., or Polysorbate 80, N.F.; 11/3 pounds of thymol, N.F.; 11/3... of any two or more denaturing materials listed under Formula No. 38-B, plus sufficient boric acid, N..., U.S.P., 2.6 fluid ounces of hydrochloric acid, N.F., and a total of 3 pounds of any two or more of...

27 CFR 21.68 - Formula No. 38-F.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Six pounds of either boric acid, N.F., or Polysorbate 80, N.F.; 11/3 pounds of thymol, N.F.; 11/3... of any two or more denaturing materials listed under Formula No. 38-B, plus sufficient boric acid, N..., U.S.P., 2.6 fluid ounces of hydrochloric acid, N.F., and a total of 3 pounds of any two or more of...

Effect of mixed antimicrobial agents and flavors in active packaging films.

PubMed

Gutiérrez, Laura; Escudero, Ana; Batlle, Ramón; Nerín, Cristina

2009-09-23

Active packaging is an emerging food technology to improve the quality and safety of food products. Many works have been developed to study the antimicrobial activity of essential oils. Essential oils have been traditionally used as flavorings in food, so they have an important odor impact but they have as well antimicrobial properties that could be used to protect the food. Recent developments in antimicrobial active packaging showed the efficiency of essential oils versus bread and bakery products among other applications. However, one of the main problems to face is the odor and taste they could provide to the packaged food. Using some aromas to mask the odor could be a good approach. That is why the main objective of this paper is to develop an antimicrobial packaging material based on the combination of the most active compounds of essential oils (hydrocinnamaldehyde, oregano essential oil, cinnamaldehyde, thymol, and carvacrol) together with some aromas commonly used in the food industry. A study of the concentration required to get the antimicrobial properties, the organoleptic compatibility with typical aroma present in many food systems (vanilla, banana, and strawberry), and the right combination of both systems has been carried out. Antimicrobial tests of both the mentioned aromas, the main components of some essential oils, and the combination of both groups were carried out against bacteria (Enterococcus faecalis, Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Salmonella choleraesuis, Yersinia enterocolitica, Escherichia coli), yeasts (Candida albicans, Debaryomyces hansenii, Zygosaccharomyces rouxii), and molds (Botrytis cinerae, Aspergillus flavus, Penicillium roqueforti, Eurotium repens, Penicillium islandicum, Penicillium commune, Penicillium nalgiovensis). The sensory properties of the combinations were evaluated with a triangular test and classification was by an order test; the odor threshold of the aroma compounds was also studied. The results reveal that none of the aromas had antimicrobial properties. The most antimicrobial compounds are thymol, carvacrol, and cinnamaldehyde, but none of them could be combined with banana aroma, whereas only thymol with strawberry aroma gave the right combined organoleptic profile. All of the antimicrobials under study could be combined with vanilla aroma, providing both antimicrobial property and the odor expected.

Introducing Organic Chemistry Students to Natural Product Isolation Using Steam Distillation and Liquid Phase Extraction of Thymol, Camphor, and Citral, Monoterpenes Sharing a Unified Biosynthetic Precursor

ERIC Educational Resources Information Center

McLain, Katherine A.; Miller, Kenneth A.; Collins, William R.

2015-01-01

Plants have provided and continue to provide the inspiration and foundation for modern medicines. Natural product isolation is a key component of the process of drug discovery from plants. The purpose of this experiment is to introduce first semester undergraduate organic chemistry students, who have relatively few lab techniques at their…

Effect of chlorhexidine/thymol and fluoride varnishes on dental biofilm formation in vitro.

PubMed

Takeuchi, Yasuo; Guggenheim, Bernhard; Filieri, Anna; Baehni, Pierre

2007-12-01

This study evaluated the effect of chlorhexidine/thymol (CHX/T) and fluoride (F) varnishes on biofilm formation in vitro. Hydroxyapatite discs coated with varnish were first immersed in saline for 0, 3, 7 or 14 d, then immersed in pasteurized saliva. The discs were incubated for 20 h with a bacterial suspension containing Actinomyces naeslundii, Fusobacterium nucleatum, Streptococcus oralis, and Veillonella dispar. Uncoated discs were used as controls. Growth of bacteria on the discs was evaluated by culture and by scanning electron microscopy (SEM). Bacterial vitality was examined by fluorescence staining. In the CHX/T-treated group, bacterial accumulation was delayed, and the total number of bacteria was significantly lower than in the controls. In the F-treated group, the total number of bacteria did not differ from the control, although the number of S. oralis was lower. Bacterial vitality in the CHX/T and F groups did not differ from that in the controls. The total number of bacteria on the CHX/T-treated discs immersed in saline was significantly higher than that on the non-immersed discs. Biofilm development was inhibited by the CHX/T varnish but not by the F varnish. The effect of the CHX/T varnish decreased following the immersion of discs in saline.

Insecticidal and acetylcholine esterase inhibition activity of Apiaceae plant essential oils and their constituents against adults of German cockroach (Blattella germanica).

PubMed

Yeom, Hwa-Jeong; Kang, Jae Soon; Kim, Gil-Hah; Park, Il-Kwon

2012-07-25

We evaluated the insecticidal and acetylcholine esterase (AChE) inhibition activity of 11 Apiaceae plant essential oils and their constituents in adult male and female Blattella germanica. Of the 11 Apiaceae plant essential oils tested, dill (Anethum graveolens), carvi (Carum carvi), and cumin (Cuminum cyminum) demonstrated >90% fumigant toxicity against adult male German cockroaches at a concentration of 5 mg/filter paper. In a contact toxicity test, dill (Anethum graveolens), carvi (Carum carvi), cumin (Cuminum cyminum), and ajowan (Trachyspermum ammi) produced strong insecticidal activity against adult male and female German cockroaches. Among the test compounds, (S)-(+)-carvone, 1,8-cineole, trans-dihydrocarvone, cuminaldehyde, trans-anethole, p-cymene, and γ-terpinene demonstrated strong fumigant toxicity against adult male and female B. germanica. In a contact toxicity test, carveol, cuminaldehyde, (S)-(+)-carvone, trans-anethole, thymol, and p-cymene showed strong contact toxicity against adult male and female B. germanica. IC(50) values of α-pinene, carvacrol, and dihydrocarvone against female AChE were 0.28, 0.17, and 0.78 mg/mL, respectively. The toxicity of the blends of constituents identified in 4 active oils indicated that carvone, cuminaldehyde, and thymol were major contributors to the fumigant activity or contact toxicity of the artificial blend.

Bioactive Secondary Metabolites from Schizogyne sericea (Asteraceae) Endemic to Canary Islands.

PubMed

Venditti, Alessandro; Bianco, Armandodoriano; Muscolo, Camilla; Zorzetto, Christian; Sánchez-Mateo, Candelaria C; Rabanal, Rosa M; Quassinti, Luana; Bramucci, Massimo; Damiano, Silvia; Iannarelli, Romilde; Lupidi, Giulio; Papa, Fabrizio; Petrelli, Dezemona; Vitali, Luca A; Vittori, Sauro; Maggi, Filippo

2016-07-01

Schizogyne sericea (Asteraceae) is a halophytic shrub endemic to the Canary Islands and traditionally employed as analgesic, astringent, anti-inflammatory, and vulnerary. A comprehensive phytochemical investigation was conducted on the flowering aerial parts by analyzing both essential oil constituents and polar compounds. The essential oil was dominated by p-cymene, with the noteworthy occurrence of β-pinene and thymol esters. From the EtOH extract, eight compounds were isolated and structurally elucidated. Essential oil, polar fractions, and isolates (2), (4), and (5) were separately in vitro assayed for antiproliferative activity on human tumor cell lines (A375, MDA-MB 231, and HCT116) by MTT assay, for antioxidant potential by DPPH, ABTS, and FRAP assays, and for antimicrobial activity by the agar disk diffusion method. Results revealed that essential oil and compounds 1 and 2 exert a strong inhibition on tumor cells, and in some cases, higher than that of cisplatin. Fractions containing thymol derivatives (1 and 2) and caffeoylquinic acid derivatives 4 and 5 displayed antioxidant activity comparable to that of Trolox, making S. sericea extract an interesting natural product with potential applications as preservative or in the treatment of diseases in which oxidative stress plays an important role. © 2016 Wiley-VHCA AG, Zürich.

Impact of Moderate Heat, Carvacrol, and Thymol Treatments on the Viability, Injury, and Stress Response of Listeria monocytogenes

PubMed Central

Guevara, L.; Antolinos, V.; Palop, A.; Periago, P. M.

2015-01-01

The microbial safety and stability of minimally processed foods are based on the application of combined preservative factors. Since microorganisms are able to develop adaptive networks to survive under conditions of stress, food safety may be affected, and therefore understanding of stress adaptive mechanisms plays a key role in designing safe food processing conditions. In the present study, the viability and the sublethal injury of Listeria monocytogenes exposed to moderate heat (55°C) and/or essential oil compounds (carvacrol and thymol, 0.3 mM) treatments were studied. Synergistic effects were obtained when combining mild heat (55°C) with one or both essential oil compounds, leading to inactivation kinetics values three to four times lower than when using heat alone. All the treatments applied caused some injury in the population. The injury levels ranged from around 20% of the surviving population under the mildest conditions to more than 99.99% under the most stringent conditions. Protein extracts of cells exposed to these treatments were analysed by two-dimensional gel electrophoresis. The results obtained revealed that stressed cells exhibited differential protein expression to control cells. The proteins upregulated under these stressing conditions were implicated, among other functions, in stress response, metabolism, and protein refolding. PMID:26539510

Thymus vulgaris essential oil and thymol against Alternaria alternata (Fr.) Keissler: effects on growth, viability, early infection and cellular mode of action.

PubMed

Perina, Fabiano J; Amaral, Douglas C; Fernandes, Rafael S; Labory, Claudia Rg; Teixeira, Glauco A; Alves, Eduardo

2015-10-01

In initial assays, Thymus vulgaris essential oil (TEO) has demonstrated activity against several plant-pathogenic fungi and has reduced the fungal diseases to levels comparable with commercial fungicides. Thus, the goal of this work was to identify the mode of action in fungi of TEO and its major compound thymol (TOH) at the cellular level using an ultrastructure approach. TEO from leaves and TOH had minimum inhibitory concentrations (MICs) of 500 and 250 µg mL(-1) respectively against A. alternata; under the same conditions, MIC for a commercial fungicide was 1250 µg mL(-1) . Ultrastructure analysis showed that TOH phenolic substance prevented fungal growth, reduced fungal viability and prevented the penetration in fruits by a cell wall/plasma membrane interference mode of action with organelles targeted for destruction in the cytoplasm. Such mode of action differs from protective and preventive-curative commercial fungicides used as pattern control. These findings suggest that TOH was responsible for the antifungal activity of TEO. Therefore, both the essential oil and its major substance have potential for use in the development of new phenolic structures and analogues to control Alternaria brown spot disease caused by Alternaria alternata. © 2014 Society of Chemical Industry.

Method for Bacterial Growth and Ammonia Production and Effect of Inhibitory Substances in Disposable Absorbent Hygiene Products.

PubMed

Forsgren-Brusk, Ulla; Yhlen, Birgitta; Blomqvist, Marie; Larsson, Peter

The purpose of this study was to evaluate a pragmatic laboratory method to provide a technique for developing incontinence products better able to reduce malodor when used in the clinical setting. Bacterial growth and bacterially formed ammonia in disposable absorbent incontinence products was measured by adding synthetic urine inoculated with bacteria to test samples cut from the crotch area of the product. The inhibitory effect's of low pH (4.5 and 4.9) and 3 antimicrobial substances-chlorhexidine, polyhexamethylene biguanide (PHMB), and thymol-at 2 concentrations each, were studied. From the initial inocula of 3.3 log colony-forming units per milliliter (cfu/mL) at baseline, the bacterial growth of the references increased to 5.0 to 6.0 log cfu/mL at 6 hours for Escherichia coli, Proteus mirabilis, and Enterococcus faecalis. At 12 hours there was a further increase to 7.0 to 8.9 log cfu/mL. Adjusting the pH of the superabsorbent in the incontinence product from 6.0 to pH 4.5 and pH 4.9 significantly (P < .05) inhibited the bacterial growth rates, in most cases, both at 6 and 12 hours. The effect was most pronounced at pH 4.5. Chlorhexidine had significant (P < .05) inhibitory effect on E. coli and E. faecalis, and at 12 hours also on P. mirabilis. For PHMB and thymol the results varied. At 6 hours, the ammonia concentration in the references (pH 6.0) was 200 to 300 ppm and it was 1500 to 1600 ppm at 8 hours. At pH 4.5, no or little ammonia production was measured at 6 and 8 hours. At pH 4.9, there was a significant reduction (P < .01). Chlorhexidine and PHMB exerted a significant (P < .01 or P < .001) inhibitory effect on ammonia production at both concentrations and at 6 and 8 hours. Thymol 0.003% and 0.03% showed inhibitory effect at both 6 hours (P < .01 or P < .001) and at 8 hours (P < .05 or P < .001). The method described in this study can be used to compare the ability of various disposable absorbent products to inhibit bacterial growth and ammonia production. This technique, we describe, provides a pragmatic method for assessing the odor-inhibiting capacity of specific incontinence products.

Use of Pinus sylvestris L. (Pinaceae), Origanum vulgare L. (Lamiaceae), and Thymus vulgaris L. (Lamiaceae) essential oils and their main components to enhance itraconazole activity against azole susceptible/not-susceptible Cryptococcus neoformans strains.

PubMed

Scalas, Daniela; Mandras, Narcisa; Roana, Janira; Tardugno, Roberta; Cuffini, Anna Maria; Ghisetti, Valeria; Benvenuti, Stefania; Tullio, Vivian

2018-05-03

Cryptococcal infections, besides being a problem for immunocompromised patients, are occasionally being a problem for immunocompetent patients. In addition, the lower susceptibility of this yeast to azoles is a growing problem in health care. To date, there are very few molecules with any activity towards Cryptococcus neoformans, leading to heightened interest in finding new alternatives or adjuvants to conventional drugs for the treatment of mycosis caused by this yeast. Since the essential oils (EOs) are considered as a potential rich source of bioactive antimicrobial compounds, we evaluated the antifungal activity of Origanum vulgare (oregano), Pinus sylvestris (pine), and Thymus vulgaris (thyme red) EOs, and their components (α-pinene, carvacrol, thymol) compared with fluconazole, itraconazole, and voriconazole, against C.neoformans clinical strains. Then, we investigated the effect of EOs and components in combination with itraconazole. EO composition was analysed by Gas chromatography-mass spectrometry (GC-MS). A broth microdilution method was used to evaluate the susceptibility of C.neoformans to azoles, EOs and components. Checkerboard tests, isobolograms and time-kill assays were carried out for combination studies. Six C.neoformans isolates were susceptible to azoles, while one C.neoformans exhibited a reduced susceptibility to all tested azole drugs. All EOs exerted a good inhibitory activity against all C.neoformans strains. Pine EO was the most effective. Among components, thymol exerted the most remarkable activity. By checkerboard testing and isobolographic analysis, combinations of itraconazole with oregano, pine, or thyme EOs, and carvacrol were found to be synergistic (FICI≤0.5) against azole susceptible C.neoformans. Regarding the azole not susceptible C.neoformans strain, the synergistic effect with itraconazole was observed with thyme EO (chemotype: thymol 26.52%; carvacrol 7.85%), and carvacrol. Time-kill assays confirmed the synergistic effects of itraconazole and oregano or thyme EO against azole susceptible C.neoformans. Binary mixtures of itraconazole/thyme EO or carvacrol yielded additive effects on the azole not susceptible C.neoformans. Our findings highlight the potential effectiveness of thyme, oregano EOs, and carvacrol as natural and cost-effective adjuvants when used in combination with itraconazole. Identification of EOs exerting these effects could be one of the feasible ways to overcome drug resistance, reducing drug concentration and side effects.

Microencapsulation, Chemical Characterization, and Antimicrobial Activity of Mexican (Lippia graveolens H.B.K.) and European (Origanum vulgare L.) Oregano Essential Oils

PubMed Central

Regalado-González, Carlos; Vázquez-Landaverde, Pedro; Guerrero-Legarreta, Isabel; García-Almendárez, Blanca E.

2014-01-01

The effect of solvent polarity (methanol and pentane) on the chemical composition of hydrodistilled essential oils (EO's) of Lippia graveolens H.B.K. (MXO) and Origanum vulgare L. (EUO) was studied by GC-MS. Composition of modified starch microencapsulated EO's was conducted by headspace-solid-phase microextraction (HS-SPME). The antimicrobial activity of free and microencapsulated EO's was evaluated. They were tested against Salmonella sp., Brochothrix thermosphacta, Pseudomonas fragi, Lactobacillus plantarum, and Micrococcus luteus. Thymol and carvacrol were among the main components of EO's and their free and microencapsulated inhibitory activity was tested against M. luteus, showing an additive combined effect. Chemical composition of EO's varied according to the solvent used for GC analysis and to volatile fraction as evaluated by HS-SPME. Thymol (both solvents) was the main component in essential oil of MXO, while carvacrol was the main component of the volatile fraction. EUO showed α-pinene (methanol) and γ-terpinene (pentane) as major constituents, the latter being the main component of the volatile fraction. EO's showed good stability after 3 months storage at 4°C, where antimicrobial activity of microencapsulated EO's remained the same, while free EO's decreased 41% (MXO) and 67% (EUO) from initial activity. Microencapsulation retains most antimicrobial activity and improves stability of EO's from oregano. PMID:25177730

Antibacterial effects of fluoride varnish compared with chlorhexidine plus fluoride in disabled children.

PubMed

Baygin, Ozgul; Tuzuner, Tamer; Kusgoz, Adem; Senel, Ahmet Can; Tanriver, Mehmet; Arslan, Ipek

2014-01-01

To evaluate the effects of fluoride varnish vs a combination of chlorhexidine-thymol varnish plus a gel containing chlorhexidine and fluoride on oral hygiene and caries prevention in disabled children. Ninety patients aged 3-17 years who were treated under general anaesthesia were randomly assigned into three groups as follows: group 1: Fluor Protector (0.1% fluoride varnish); group 2: Cervitec Plus (1% chlorhexidine- 1% thymol varnish) + Cervitec Gel (0.2% chlorhexidine-0.2% sodium fluoride); group 3: control (toothbrushing only). Mutans streptococci (MS) and lactobacilli (LB) levels, visible plaque index (VPI) and gingival bleeding index (GBI) were evaluated at four stages: T0, before general anaesthesia; T1, one month after treatment; T2, six months after treatment; T3, twelve months after treatment. The data were evaluated using Kruskal-Wallis and Mann-Whitney U-tests (P < 0.05). Groups 1 and 2 showed significantly lower scores than group 3 for all parameters at T1 and T2. No statistically significant difference was detected among any of the the groups at T3 (P > 0.05). The use of materials that include both fluoride and chlorhexidine as routine treatment of children with disability may increase the success of restorations by improving oral hygiene, reduce the need for future restorative treatments and thus the need for general anaesthesia.

Larvicidal Activity of Essential Oils of Five Apiaceae Taxa and Some of Their Main Constituents Against Culex quinquefasciatus.

PubMed

Pavela, Roman; Maggi, Filippo; Cianfaglione, Kevin; Bruno, Maurizio; Benelli, Giovanni

2018-01-01

Apiaceae are aromatic herbs producing essential oils which are used on an industrial scale for various purposes. Notably, Apiaceae essential oils may replace synthetic insecticides keeping most of their efficacy and avoiding environmental pollution and human poisoning. In the present work, we explored the insecticidal potential of the essential oils from five Apiaceae taxa, namely Sison amomum, Echinophora spinosa, Heracleum sphondylium subsp. sphondylium, Heracleum sphondylium subsp. ternatum, and Trachyspemum ammi, as well as their major constituents (sabinene, p-cymene, terpinolene, myristicin, and thymol), against the filariasis vector Culex quinquefasciatus. For the purpose, the essential oils were obtained by hydrodistillation and their composition was achieved by gas chromatography/mass spectrometry (GC/MS). Their acute toxicity on third instar larvae of C. quinquefasciatus was determined. The two most active essential oils were those from T. ammi fruits and E. spinosa roots, showing LC 50 below 20 μl/l and LD 90 below 50 μl/l. These oils were dominated by the monoterpene phenol thymol and the phenylpropanoid myristicin, respectively, which showed the strongest larvicidal activity (LC 50 of 15.1 and 16.3 μl/l, respectively) among the pure compounds tested. These results showed that Apiaceae may be useful as source of larvicidal compounds to be used for the development of cheap, effective and eco-friendly insecticidal formulations. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

Insecticidal Properties of Essential Oils and Some of Their Constituents on the Turkestan Cockroach (Blattodea: Blattidae).

PubMed

Gaire, Sudip; O'Connell, Mary; Holguin, Francisco O; Amatya, Anup; Bundy, Scott; Romero, Alvaro

2017-04-01

The Turkestan cockroach, Blatta lateralis (Walker), has become the most important peridomestic species in urban areas of the Southwestern United States. The aim of this study was to evaluate the use of botanical compounds to control this urban pest. We tested the acute toxicity and repellency of six botanical constituents and three essential oils on Turkestan cockroach nymphs. Chemical composition of the essential oils was also determined. Topical and fumigant assays with nymphs showed that thymol was the most toxic essential oil constituent, with a LD50 of 0.34 mg/nymph and a LC50 of 27.6 mg/liter air, respectively. Contact toxicity was also observed in assays with trans-Cinnamaldehyde, eugenol, geraniol, methyl eugenol, and p-Cymene. Methyl eugenol and geraniol had limited fumigant toxicity. The essential oils from red thyme, clove bud, and Java citronella exhibited toxicity against nymphs. Cockroaches avoided fresh dry residues of thymol and essential oils. Chemical analysis of the essential oils confirmed high contents of effective essential oil constituents. Our results demonstrated that essential oils and some of their constituents have potential as eco-friendly insecticides for the management of Turkestan cockroaches. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of carvacrol and thymol on the physiological attributes, enterotoxin production and surface characteristics of Staphylococcus aureus strains isolated from foods

PubMed Central

Souza, E.L.; Oliveira, C.E.V.; Stamford, T.L.M.; Conceição, M.L.; Neto, N.J. Gomes

2013-01-01

This study evaluated the influence of the phenolic compounds carvacrol (CAR) and thymol (THY) on some physiological characteristics and on the modulation of the secretion of some staphylococcal virulence factors, that is, coagulase and enterotoxin. This study also investigated possible mechanisms for the establishment of the anti-staphylococcal activity of these compounds. Sublethal concentrations (0.3 and 0.15 μL/mL) of CAR and THY inhibited the activity of the enzymes coagulase and lipase and led to a decrease in salt tolerance. At the tested sublethal concentrations, both CAR and THY led to a total suppression of enterotoxin production. The loss of a 260-nm-absorbing material and an efflux of potassium ions occurred immediately after the addition of CAR and THY at 0.6 and 1.2 μL/mL and increased up to 120 min of exposure. Electron microscopy of cells exposed to CAR and THY (0.6 μL/mL) revealed that individual cells appeared to be deformed, with projections of cellular material. The observations of leakage of cellular material and an altered cell surface suggest that gross damage to a cell’s cytoplasmic membrane, which results in a disruption in protein secretion, could be responsible for the anti-staphylococcal properties of CAR and THY. PMID:24159280

Combined effect of MAP and active compounds on fresh blue fish burger.

PubMed

Del Nobile, M A; Corbo, M R; Speranza, B; Sinigaglia, M; Conte, A; Caroprese, M

2009-11-15

The combined effects of three essential oils [thymol, lemon extract and grapefruit seed extract (GFSE)] and modified atmosphere packaging conditions (MAP) on quality retention of blue fish burgers was studied and discussed. In particular, samples were packaged in air and in three different gas mix compositions: 30:40:30 O(2):CO(2):N(2), 50:50 O(2):CO(2) and 5:95 O(2):CO(2). During a 28-day storage period at 4 degrees C, the nutritional, microbiological and sensorial quality of the packed products was assessed. The potential development of biogenic amines was also evaluated. The obtained results highlight the possibility to improve the microbial quality of blue fish burgers by using very small amount of thymol (110ppm), GFSE (100ppm) and lemon extract (120ppm) in combination with MAP. Based primarily on microbiological results, the combined use of the tested natural preservatives and a packaging system characterized by a high CO(2)-concentration, was able to guarantee the microbial acceptability of fish burgers until the 28th day of storage at 4 degrees C. On the other hand, results from sensory analyses showed that sensorial quality was the sub-index that limited the burgers shelf life (to about 22-23days), even if the proposed strategy was also effective in minimizing the sensory quality loss of the product having no effect on its nutritional quality.

Effect of Nanoemulsified and Microencapsulated Mexican Oregano (Lippia graveolens Kunth) Essential Oil Coatings on Quality of Fresh Pork Meat.

PubMed

Hernández-Hernández, Elvia; Lira-Moreno, César Y; Guerrero-Legarreta, Isabel; Wild-Padua, Graciela; Di Pierro, Prospero; García-Almendárez, Blanca E; Regalado-González, Carlos

2017-06-01

Fresh meat is a highly perishable food. This work aimed to evaluate the influence of Mexican oregano (Lippia graveolens Kunth) incorporated into active coatings (ACs) spread on fresh pork meat as free (FEO), nanoemulsified (NEO), and microencapsulated (MEO) essential oil (EO), on its microbiological, physicochemical and sensory properties during 15 d at 4 ± 1 °C. Thymol and γ-terpinene were identified in the EO. In vitro effect of 2.85 mg EO/cm 2 was tested against Brochothrix thermosphacta, Micrococcus luteus, Lactobacillus plantarum, Pseudomonas fragi, and Salmonella Infantis. FEO antioxidant capacity (DPPH assay) was significantly higher than that of thymol, NEO and MEO (93.53%, 89.92%, 77.79%, and 78.50% inhibition, respectively), and similar to BHA (96.03%) and gallic acid (95.57%). FEO, NEO, and MEO ACs on meat caused growth inhibition of lactic acid bacteria (5 log population reduction) and Pseudomonas spp. (4 log reduction), whereas ≤1.5 log population reduction was observed for B. thermosphacta and Salmonella Infantis. Meat microbiota was more efficiently controlled by MEO than by FEO or NEO. ACs delayed lipid and oxymyoglobin oxidation of fresh pork meat. After 15 d of cold storage meat added with EO coatings was desirable for panelists, whereas untreated (UT) samples were undesirable. Active coatings are a significant alternative method for fresh meat preservation. © 2017 Institute of Food Technologists®.

On-line solid phase selective separation and preconcentration of Cd(II) by solid-phase extraction using carbon active modified with methyl thymol blue.

PubMed

Ensafi, Ali A; Ghaderi, Ali R

2007-09-05

An on-line flow system was used to develop a selective and efficient on-line sorbent extraction preconcentration system for cadmium. The method is based on adsorption of cadmium ions onto the activated carbon modified with methyl thymol blue. Then the adsorbed ions were washed using 0.5M HNO(3) and the eluent was used to determine the Cd(II) ions using flame atomic absorption spectrometry. The results obtained show that the modified activated carbon has the greatest adsorption capacity of 80 microg of Cd(II) per 1.0 g of the solid phase. The optimal pH value for the quantitative preconcentration was 9.0 and full desorption is achieved by using 0.5M HNO(3) solution. It is established that the solid phase can be used repeatedly without a considerable adsorption capacity loss. The detection limit was less than 1 ngmL(-1) Cd(II), with an enrichment factor of 1000. The calibration graph was linear in the range of 1-2000 ngmL(-1) Cd(II). The developed method has been applied to the determination of trace cadmium (II) in water samples and in the following reference materials: sewage sludge (CRM144R), and sea water (CASS.4) with satisfactory results. The accuracy was assessed through recovery experiments.

Microencapsulation, chemical characterization, and antimicrobial activity of Mexican (Lippia graveolens H.B.K.) and European (Origanum vulgare L.) oregano essential oils.

PubMed

Hernández-Hernández, Elvia; Regalado-González, Carlos; Vázquez-Landaverde, Pedro; Guerrero-Legarreta, Isabel; García-Almendárez, Blanca E

2014-01-01

The effect of solvent polarity (methanol and pentane) on the chemical composition of hydrodistilled essential oils (EO's) of Lippia graveolens H.B.K. (MXO) and Origanum vulgare L. (EUO) was studied by GC-MS. Composition of modified starch microencapsulated EO's was conducted by headspace-solid-phase microextraction (HS-SPME). The antimicrobial activity of free and microencapsulated EO's was evaluated. They were tested against Salmonella sp., Brochothrix thermosphacta, Pseudomonas fragi, Lactobacillus plantarum, and Micrococcus luteus. Thymol and carvacrol were among the main components of EO's and their free and microencapsulated inhibitory activity was tested against M. luteus, showing an additive combined effect. Chemical composition of EO's varied according to the solvent used for GC analysis and to volatile fraction as evaluated by HS-SPME. Thymol (both solvents) was the main component in essential oil of MXO, while carvacrol was the main component of the volatile fraction. EUO showed α-pinene (methanol) and γ-terpinene (pentane) as major constituents, the latter being the main component of the volatile fraction. EO's showed good stability after 3 months storage at 4°C, where antimicrobial activity of microencapsulated EO's remained the same, while free EO's decreased 41% (MXO) and 67% (EUO) from initial activity. Microencapsulation retains most antimicrobial activity and improves stability of EO's from oregano.

Antimelanogenic Efficacy of Melasolv (3,4,5-Trimethoxycinnamate Thymol Ester) in Melanocytes and Three-Dimensional Human Skin Equivalent.

PubMed

Lee, John Hwan; Lee, Eun-Soo; Bae, Il-Hong; Hwang, Jeong-Ah; Kim, Se-Hwa; Kim, Dae-Yong; Park, Nok-Hyun; Rho, Ho Sik; Kim, Yong Jin; Oh, Seong-Geun; Lee, Chang Seok

2017-01-01

Excessive melanogenesis often causes unaesthetic hyperpigmentation. In a previous report, our group introduced a newly synthesized depigmentary agent, Melasolv™ (3,4,5-trimethoxycinnamate thymol ester). In this study, we demonstrated the significant whitening efficacy of Melasolv using various melanocytes and human skin equivalents as in vitro experimental systems. The depigmentary effect of Melasolv was tested in melan-a cells (immortalized normal murine melanocytes), α-melanocyte-stimulating hormone (α-MSH)-stimulated B16 murine melanoma cells, primary normal human melanocytes (NHMs), and human skin equivalent (MelanoDerm). The whitening efficacy of Melasolv was further demonstrated by photography, time-lapse microscopy, Fontana-Masson (F&M) staining, and 2-photon microscopy. Melasolv significantly inhibited melanogenesis in the melan-a and α-MSH-stimulated B16 cells. In human systems, Melasolv also clearly showed a whitening effect in NHMs and human skin equivalent, reflecting a decrease in melanin content. F&M staining and 2-photon microscopy revealed that Melasolv suppressed melanin transfer into multiple epidermal layers from melanocytes as well as melanin synthesis in human skin equivalent. Our study showed that Melasolv clearly exerts a whitening effect on various melanocytes and human skin equivalent. These results suggest the possibility that Melasolv can be used as a depigmentary agent to treat pigmentary disorders as well as an active ingredient in cosmetics to increase whitening efficacy. © 2017 S. Karger AG, Basel.

An efficacious oral health care protocol for immunocompromised patients.

PubMed

Solomon, C S; Shaikh, A B; Arendorf, T M

1995-01-01

A twice-weekly oral and perioral examination was provided to 120 patients receiving antineoplastic therapy. Sixty patients were monitored while following the traditional hospital oral care protocol (chlorhexidine, hydrogen peroxide, sodium bicarbonate, thymol glycol, benzocaine mouthrinse, and nystatin). The mouth care protocol was then changed (experimental protocol = chlorhexidine, benzocaine lozenges, amphotericin B lozenges), and patients were monitored until the sample size matched that of the hospital mouth care regime. There was a statistically significant reduction in oral complications upon introduction and maintenance of the experimental protocol.

Feeding Essential Oils and 2-Heptanone in Sugar Syrup and Protein Diets to Honey Bees (Apis mellifera L.) as Potential Varroa Mite (Varroa destructor) Controls and Traced by SPME (Solid Phase Micro Extraction) Fibers

USDA-ARS?s Scientific Manuscript database

Essential oils and oil components were fed to honey bees in a sugar syrup and liquid protein diet in order to determine if the oils were being incorporated into the bee larvae and could be traced by means of SPME. The compounds used were origanum, 2-heptanone, thymol and connamon oil. The main com...

Copper and dyes enhance laccase production in gamma-proteobacterium JB.

PubMed

Malhotra, Kanam; Sharma, Prince; Capalash, Neena

2004-07-01

Laccase production in gamma-proteobacterium JB was enhanced 13-fold by adding 0.1 mM CuSO(4) 24 h after the onset of growth. Ethidium bromide (2.5 microM), Malachite Green, Phenol Red and Thymol Blue (10 microM each) enhanced laccase production 17-, 19-, 4- and 2-fold, respectively. Among the fourteen aromatic/organic compounds tried, p-aminobenzoic acid and an industrial effluent, from where the organism was isolated, showed 1.2- and 1.26-fold increases in production.

To Compare the Effects of Storage Solutions 0.05% Thymol vs. 6% Sodium Hypochlorite vs. Hank’s Balanced Salt Solution on the Flexural Strength of Dentin Bars

DTIC Science & Technology

2016-05-20

ridge thicknesses, restored with composite resin and composite resin reinforced with Ribbond . Indian Journal of Dental Research . Manisha, T. (2014...in the internal structure of an extracted tooth, used to test dental materials in vitro could result in findings that cannot be replicated or...roots restored with different post systems. International Endodontic Journal . Barbosa, S. V. (1994). Influence of sodium hypochlorite on the

Does the essential oil of Lippia sidoides Cham. (pepper-rosmarin) affect its endophytic microbial community?

PubMed

da Silva, Thais Freitas; Vollú, Renata Estebanez; Jurelevicius, Diogo; Alviano, Daniela Sales; Alviano, Celuta Sales; Blank, Arie Fitzgerald; Seldin, Lucy

2013-02-07

Lippia sidoides Cham., also known as pepper-rosmarin, produces an essential oil in its leaves that is currently used by the pharmaceutical, perfumery and cosmetic industries for its antimicrobial and aromatic properties. Because of the antimicrobial compounds (mainly thymol and carvacrol) found in the essential oil, we believe that the endophytic microorganisms found in L. sidoides are selected to live in different parts of the plant. In this study, the endophytic microbial communities from the stems and leaves of four L. sidoides genotypes were determined using cultivation-dependent and cultivation-independent approaches. In total, 145 endophytic bacterial strains were isolated and further grouped using either ERIC-PCR or BOX-PCR, resulting in 76 groups composed of different genera predominantly belonging to the Gammaproteobacteria. The endophytic microbial diversity was also analyzed by PCR-DGGE using 16S rRNA-based universal and group-specific primers for total bacteria, Alphaproteobacteria, Betaproteobacteria and Actinobacteria and 18S rRNA-based primers for fungi. PCR-DGGE profile analysis and principal component analysis showed that the total bacteria, Alphaproteobacteria, Betaproteobacteria and fungi were influenced not only by the location within the plant (leaf vs. stem) but also by the presence of the main components of the L. sidoides essential oil (thymol and/or carvacrol) in the leaves. However, the same could not be observed within the Actinobacteria. The data presented here are the first step to begin shedding light on the impact of the essential oil in the endophytic microorganisms in pepper-rosmarin.

The Usefulness of Non-Toxic Plant Metabolites in the Control of Bacterial Proliferation.

PubMed

Gutiérrez, Sergio; Morán, Alfredo; Martínez-Blanco, Honorina; Ferrero, Miguel A; Rodríguez-Aparicio, Leandro B

2017-09-01

The effect of generally recognised as safe (GRAS) plant metabolites in regulating the growth of human pathogenic and probiotic bacteria and in the formation of biofilm was investigated. Thymol, carvacrol and eugenol showed the strongest antibacterial action against both pathogenic and probiotic microorganisms, at a subinhibitory concentration (SIC) of ≤50 μg ml -1 . Genistein, hydroquinone, p-hydroxybenzoic acid and resveratrol also showed antibacterial effects but at a wide concentration range (SIC = 50-1000 μg ml -1 ). Catechin, gallic acid, protocatechuic acid and cranberry extracts were the most biologically compatible molecules (SIC ≥ 1000 μg ml -1 ). Regarding the effect on biofilm, it was observed that thymol, carvacrol and eugenol showed antibiofilm activity against all potential pathogenic bacteria tested whilst specifically enhancing probiotic aggregation. Catechin, genistein and cranberry extracts did not inhibit the pathogenic aggregation but they stimulated probiotic biofilm formation, whilst gallic acid, protocateuchic acid, hydroquinone, p-hydroxybenzoic acid and resveratrol did not show opposite effect on biofilm formation between pathogenic and probiotic microorganisms. These results indicate that an appropriate combination of GRAS plant metabolites, which have traditionally been used as dietary constituents due to their health-promoting characteristics, can also be extremely useful in the regulation of bacterial proliferation in the intestinal microbiota. Hence, it is suggested to apply these natural GRAS molecules as dietary supplements in the food industry in order to promote probiotic viability and to prevent or reduce colonisation or proliferation of intestinal pathogens.

Synergistic interaction of ten essential oils against Haemonchus contortus in vitro.

PubMed

Katiki, L M; Barbieri, A M E; Araujo, R C; Veríssimo, C J; Louvandini, H; Ferreira, J F S

2017-08-30

Anthelmintic resistance in sheep gastrointestinal nematodes is a worldwide problem. Multi-drug resistant haemonchosis is the most serious impediment for small ruminant systems, and there are no new drug candidates currently under development. Molecules from natural sources have demonstrated anthelmintic activity against parasites. In this work, the monoterpenoids carvacrol, carvone, cineole, linalool, limonene, and thymol and the phenylpropanoids cinnamaldehyde, anethole, vanillin, and eugenol were assessed individually or in mixtures of ten binary, three ternary, and three quaternary combinations using the in vitro egg hatch assay with eggs of a multi-drug resistant strain of Haemonchus contortus. The main objective of this study was to identify the most effective interaction among essential oils with the greatest individual anthelmintic efficacy and to determine the most powerful combinations. The essential oils were ranked by their 50% lethal concentration (LC 50 ) as follows (mg/mL): cinamaldehyde (0.018), anethole (0.070), carvone (0.085), carvacrol (0.11), thymol (0.13), linalool (0.29), vanillin (0.57), eugenol (0.57), cineole (4.74), and limonene (207.5). Quantification of synergism, additive effect, and antagonism were calculated for binary, ternary, and quaternary combinations. The best anthelmintic effect resulting from synergistic activity among 16 different combinations was for cinnamaldehyde:carvacrol (CL 50 0.012mg/mL) and anethole:carvone (CL 50 0.013mg/mL). These results indicate that these binary combinations would be promising to be tested in sheep infected with H. contortus. Copyright © 2017 Elsevier B.V. All rights reserved.

Toxicity of Selected Acaricides to Honey Bees (Apis mellifera) and Varroa (Varroa destructor Anderson and Trueman) and Their Use in Controlling Varroa within Honey Bee Colonies.

PubMed

Gregorc, Aleš; Alburaki, Mohamed; Sampson, Blair; Knight, Patricia R; Adamczyk, John

2018-05-10

The efficacies of various acaricides in order to control a parasitic mite, the Varroa mite, Varroa destructor , of honey bees, were measured in two different settings, namely, in laboratory caged honey bees and in queen-right honey bee colonies. The Varroa infestation levels before, during, and after the acaricide treatments were determined in two ways, namely: (1) using the sugar shake protocol to count mites on bees and (2) directly counting the dead mites on the hive bottom inserts. The acaricides that were evaluated were coumaphos, tau-fluvalinate, amitraz, thymol, and natural plant compounds (hop acids), which were the active ingredients. The acaricide efficacies in the colonies were evaluated in conjunction with the final coumaphos applications. All of the tested acaricides significantly increased the overall Varroa mortality in the laboratory experiment. Their highest efficiencies were recorded at 6 h post-treatment, except for coumaphos and thymol, which exhibited longer and more consistent activity. In the honey bee colonies, a higher Varroa mortality was recorded in all of the treatments, compared with the natural Varroa mortality during the pretreatment period. The acaricide toxicity to the Varroa mites was consistent in both the caged adult honey bees and workers in the queen-right colonies, although, two of these acaricides, coumaphos at the highest doses and hop acids, were comparatively more toxic to the worker bees.

The efficacy of techniques for the disinfection of artificial sub-surface dentinal caries lesions and their effect on demineralization and remineralization in vitro.

PubMed

Preston, K P; Higham, S M; Smith, P W

2007-06-01

The efficacy of three techniques for the disinfection of artificial sub-surface root caries lesions and their response to subsequent episodes of de- and remineralization was investigated quantitatively in vitro. Sub-surface dentinal lesions (n=20), cut into four experimental blocks and deliberately contaminated with Streptococcus mutans, were subject to either steam autoclaving (121 degrees C, 5min), gamma irradiation (4100Gy), immersion in 0.1% (w/v) thymol-distilled water solution (24h) or reserved as a control. Next, the lesions were incubated aerobically in sterile nutrient broth for 24h at 37 degrees C and resultant cultures plated onto blood agar and neutralisation agar. Ten blocks from each experimental group were then immersed in an acidic buffer solution or exposed to artificial saliva for 5 days. Baseline changes in the mineral content and distribution of the lesions were assessed by transverse microradiography (TMR). Micro-organisms were recovered from each control block and one block treated by gamma irradiation. Steam autoclaving and immersion in a thymol solution significantly decreased (p<0.05) the amount of mineral lost from the body of lesions subject to a further acid challenge. Mineral ion uptake by lesions exposed to artificial saliva was significantly increased (p<0.05) through disinfection by steam autoclaving. Gamma irradiation proved the most acceptable method for the disinfection of sub-surface root dentine lesions having the least adverse effect on demineralization and remineralization.

Antibacterial and efflux pump inhibitors of thymol and carvacrol against food-borne pathogens.

PubMed

Miladi, Hanene; Zmantar, Tarek; Chaabouni, Yassine; Fedhila, Kais; Bakhrouf, Amina; Mahdouani, Kacem; Chaieb, Kamel

2016-10-01

In this study thymol (THY) and carvacrol (CAR), two monoterpenic phenol produced by various aromatic plants, was tested for their antibacterial and efflux pump inhibitors potencies against a panel of clinical and foodborne pathogenes. Our results demonstrated a substantial susceptibility of the tested bacteria toward THY and CAR. Especially, THY displayed a strong inhibitory activity (MIC's values ranged from 32 to 64 μg/mL) against the majority of the tested strains compared to CAR. Moreover, a significant reduction in MIC's of TET and benzalkonium chloride (QAC) were noticed when tested in combinations with THY and CAR. Their synergic effect was more significant in the case of THY which resulted a reduction of MIC's values of TET (2-8 fold) and QAC (2-8 fold). We noted also that THY and CAR inhibited the ethidium bromide (EtBr) cell efflux in a concentration-dependent manner. The rate of EtBr accumulation in food-borne pathogen was enhanced with THY and CAR (0, 250 and 500 μg/mL). The lowest concentration causing 50% of EtBr efflux inhibition (IC 50) was noticed in Salmonella enteritidis (1129) at 150 μg/mL of THY and 190 μg/mL of CAR respectively. These findings indicate that THY and CAR may serve as potential sources of efflux pump inhibitor in food-borne pathogens. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantitative analysis of essential oils of Thymus daenensis using laser-induced fluorescence and Raman spectroscopy.

PubMed

Khoshroo, H; Khadem, H; Bahreini, M; Tavassoli, S H; Hadian, J

2015-11-10

Laser-induced fluorescence and Raman spectroscopy are used for the investigation of different genotypes of Thymus daenensis native to the Ilam province of Iran. Different genotypes of T. daenensis essential oils, labeled T1 through T7, possess slight differences with regard to the composition of the thymol. The gas chromatography-mass spectrometry (GC-MS) method is performed to determine the concentration of each constituent as a reference method. The Raman spectra of different concentrations of pure thymol dissolved in hexane as standard samples are obtained via a laboratory prototype Raman spectroscopy setup for the calculation of the calibration curve. The regression coefficient and limit of detection are calculated. The possibility of the differentiation of different genotypes of T. daenensis is also examined by laser-induced fluorescence spectroscopy, although we do not know the exact amounts of their components. All the fluorescence spectral information is used jointly by cluster analysis to differentiate between 7 genotypes. Our results demonstrate the acceptable precision of Raman spectroscopy with GC-MS and corroborate the capacity of Raman spectroscopy in applications in the quantitative analysis field. Furthermore, the cluster analysis results show that laser-induced fluorescence spectroscopy is an acceptable technique for the rapid classification of different genotypes of T. daenensis without having any previous information of their exact amount of constituents. So, the ability to rapidly and nondestructively differentiate between genotypes makes it possible to efficiently select high-quality herbs from many samples.

Contact dermatitis to Vicks VapoRub.

PubMed

Noiles, Kristin; Pratt, Melanie

2010-01-01

Vicks VapoRub (VVR) is a commonly used inhalant ointment that helps relieve symptoms of upper respiratory tract infections. It contains several plant substances, including turpentine oil, eucalyptus oil, and cedar leaf oil, which can potentially irritate or sensitize the skin, as well as camphor, menthol, nutmeg oil, and thymol. Although many reports describe allergic contact dermatitis (ACD) to the various constituents in VVR ointment, there are no cases of VVR directly causing ACD. We present a case of a patient who developed an ACD secondary to application of her VVR.

Anti-Legionella activity of essential oil of Satureja cuneifolia.

PubMed

Dunkić, Valerija; Mikrut, Antonija; Bezić, Nada

2014-05-01

The essential oil of Satureja cuneifolia Ten. was characterized by a high concentration of the phenolic compounds carvacrol (21.3%) and thymol (9.2%). The in vitro activity of the essential oil against Legionela pneumophila serogroups (SG) I and 2-15 and Legionella spp. from different sources, using microdilution, showed that L. pneumofila is sensitive to the oil, with MICs ranging from 0.12 to 0.5%, v/v, and a MBC at 0.5 to 1%, v/v. The essential oil of S. cuneifolia was effective in the reduction of Legionellosis infections.

A Novel in vitro Bioassay to Explore the Repellent Effects of Compounds Against Mosquito Aedes aegypti (Diptera: Culicidae).

PubMed

Rehman, Junaid U; Tabanca, Nurhayat; Khan, Ikhlas A

2016-01-01

Mosquitoes are vectors for many pathogens resulting in many deaths of humans. Repellents play an important role in reducing mosquito bites and the spread of mosquito-borne diseases. Currently, Klun & Debboun (K & D) and human-arm-based bioassay systems are used to identify repellent properties of compounds, extracts, and essential oils. Risks involved with human-arm-based systems are allergic reactions and limited replicates. We are reporting an in vitro bioassay method “NCNPR repellent bioassay (NCNPR-RB)” that can closely simulate the results of the cloth patch bioassay system used to determine repellency against mosquitoes. The NCNPRRB method uses heat to attract mosquito and edible collagen sheets as an alternate to human skin. Multiple plant compounds with documented repellency were tested. DEET (N,N-diethyl-3-methylbenzamide) was used as a positive control. Treatments were prepared in EtOH and applied in dosages ranging from 0.011–1.5mg/cm2 to a 20-cm2 collagen sheet. The number of mosquitoes commencing to bite per probe was recorded visually for 1 min. The minimum effective dosage (mg/cm2) of compounds: DEET (0.021), carvacrol (0.011), thymol (0.013), undecanoic acid (0.023), thymol methyl ether (0.269), and 2-nonanone (>0.375 mg/cm2) determined in NCNPRRB were similar to those reported in literature using a cloth patch bioassay system. The NCNPR-RB can be used to screen compounds with reasonable reproducibility of the data at a faster rate than the cloth patch bioassay, which involves the use of human subjects.

Behavioral and toxicological responses of Rhodnius prolixus and Triatoma infestans (Hemiptera: Reduviidae) to 10 monoterpene alcohols.

PubMed

Moretti, A N; Zerba, E N; Alzogaray, Raúl A

2013-09-01

The effect on locomotor activity, the repellency, and the knock-down produced by 10 monoterpene alcohols were evaluated on first-instar nymphs of Rhodnius prolixus and Triatoma infestans, vectors of Chagas disease. A video tracking technique was used to evaluate locomotor activity and repellency by exposure to papers impregnated with monoterpenes. Eugenol on R. prolixus and (S)-cis-verbenol on T. infestans did not modify the locomotor activity. The remaining monoterpenes produced hyperactivity on both species, although the concentration required was at least a 1,000 times higher than that of deltamethrin (positive control). Carvacrol, eugenol, and geraniol resulted as repellent as N,N-diethyl-m-toluamide (positive control) for both species. A similar result was observed for almost every monoterpene on T. infestans. Knock-down effect was evaluated by exposing the nymphs in closed recipients. The order of increasing toxicity on R. prolixus was (KT50 values in min): geraniol (213.7) < alpha-terpineol (164.5) < linalool (124.2) < carvacrol (111.6) < eugenol (89.8) < thymol (78.9), and on T. infestans: alpha-terpineol (289.8) < eugenol (221.3) < carvacrol (164.2) < linalool (154.9) < thymol (96.7). All monoterpenes were less toxic than the positive control, dichlorvos (3.6 min for R. prolixus and 3.9 min for T. infestans). After 7 h of exposure, (-)-carveol, citronellol, and menthol (on both species) and geraniol (on T. infestans) produced < 50% of knock-down. After these results, it is worthwhile to explore more deeply the potential of these compounds as tools for controlling Chagas disease vectors.

Collection and storage of urine specimens for measurement of urolithiasis risk factors.

PubMed

Wu, Wenqi; Yang, Dong; Tiselius, Hans-Goran; Ou, Lili; Mai, Zanlin; Chen, Kang; Zhu, Hanliang; Xu, Shaohong; Zhao, Zhijian; Zeng, Guohua

2015-02-01

To evaluate how different methods for storage and preservation of urine samples affected the outcome of analysis of risk factors for stone formation. Spot urine samples were collected from 21 healthy volunteers. Each fresh urine sample was divided into ten 10-mL aliquots: 2 without preservative, 2 with thymol, 2 with toluene, 2 with hydrochloric acid (HCl), and 2 with sodium azide. One sample of each pair was stored at 4 °C and the other at room temperature. The concentrations of calcium, magnesium, sodium, phosphate, urate, oxalate, citrate, and pH in each urine sample were analyzed immediately after collection (0 hour) and after 24 and 48 hours. There were no significant differences in calcium, oxalate, magnesium, phosphate, sodium, urate or pH (without acidification) between samples with different preservation methods (P >.05). Urinary citrate, however, was significantly lower in the urine collected with HCl than when other preservatives were used, both at room temperature and at 4 °C. Urine pH was significantly higher after 48 hours than after 24 hours, whether the samples were stored at room temperature or at 4 °C. Antibacterial preservatives (eg, thymol or toluene) can be recommended as preservatives for 24-hour urine collections. Ideally, the samples should be stored at 4 °C. When HCl is used as a preservative, it seems essential to neutralize the samples before analysis. This is particularly obvious with the chromatographic method used for analysis of citrate that was used in this study. Copyright © 2015 Elsevier Inc. All rights reserved.

Efficacies of Nisin A and Nisin V Semipurified Preparations Alone and in Combination with Plant Essential Oils for Controlling Listeria monocytogenes

PubMed Central

Daly, Karen; O'Connor, Paula M.; Cotter, Paul D.; Ross, R. Paul

2015-01-01

The food-borne pathogenic bacterium Listeria is known for relatively low morbidity and high mortality rates, reaching up to 25 to 30%. Listeria is a hardy organism, and its control in foods represents a significant challenge. Many naturally occurring compounds, including the bacteriocin nisin and a number of plant essential oils, have been widely studied and are reported to be effective as antimicrobial agents against spoilage and pathogenic microorganisms. The aim of this study was to investigate the ability of semipurified preparations (SPP) containing either nisin A or an enhanced bioengineered derivative, nisin V, alone and in combination with low concentrations of the essential oils thymol, carvacrol, and trans-cinnamaldehyde, to control Listeria monocytogenes in both laboratory media and model food systems. Combinations of nisin V-containing SPP (25 μg/ml) with thymol (0.02%), carvacrol (0.02%), or cinnamaldehyde (0.02%) produced a significantly longer lag phase than any of the essential oil-nisin A combinations. In addition, the log reduction in cell counts achieved by the nisin V-carvacrol or nisin V-cinnamaldehyde combinations was twice that of the equivalent nisin A-essential oil treatment. Significantly, this enhanced activity was validated in model food systems against L. monocytogenes strains of food origin. We conclude that the fermentate form of nisin V in combination with carvacrol and cinnamaldehyde offers significant advantages as a novel, natural, and effective means to enhance food safety by inhibiting food-borne pathogens such as L. monocytogenes. PMID:25662980

Determination of cinnamaldehyde, carvacrol and thymol in feedstuff additives by pressurized liquid extraction followed by gas chromatography-mass spectrometry.

PubMed

Jiménez-Salcedo, Marta; Tena, María Teresa

2017-03-03

Specific blends of essential oils (BEOs) are promising substitutes for antibiotics to promote livestock performance and to reduce the incidence of intestinal disorders. Microencapsulation of BEOs has shown to improve their stability, bioavailability and to control their release rate once they are added to the feedstuff. The development and validation of a method for determining essential oil components such as carvacrol, thymol and cinnamaldehyde in a microencapsulated material used as feed additive is presented. Analytes were extracted from feed additives and feedstuff by pressurized liquid extraction (PLE) with methanol at 50°C for 5min. Methanol provided good recovery values and cleaner extracts than other polar organic solvents tested. However, for certain kind of composite additives ethyl acetate showed to be a better option because trans-cinnamaldehyde undergoes chemical reaction in methanol. Then PLE extracts were analysed by gas chromatography coupled to ion trap mass spectrometry in selected ion storage (SIS) mode. The analyte stability and the absence of analyte losses during the PLE process was checked by a recovery study. Also, the matrix effect was studied to assess accuracy. Recovery values were between 85 and 115% in most cases. Intra- and inter-day relative standard deviation values were less than 4 and 14%, respectively. Finally, the developed method was applied to the analysis of a microencapsulated feed additive, several composite feed additive samples containing microencapsulated BEOs and a spiked feedstuff, for quality control and in stability studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Control of Clostridium perfringens-induced necrotic enteritis in broilers by target-released butyric acid, fatty acids and essential oils.

PubMed

Timbermont, L; Lanckriet, A; Dewulf, J; Nollet, N; Schwarzer, K; Haesebrouck, F; Ducatelle, R; Van Immerseel, F

2010-04-01

The efficacy of target-released butyric acid, medium-chain fatty acids (C(6) to C(12) but mainly lauric acid) and essential oils (thymol, cinnamaldehyde, essential oil of eucalyptus) micro-encapsulated in a poly-sugar matrix to control necrotic enteritis was investigated. The minimal inhibitory concentrations of the different additives were determined in vitro, showing that lauric acid, thymol, and cinnamaldehyde are very effective in inhibiting the growth of Clostridium perfringens. The in vivo effects were studied in two trials in an experimental necrotic enteritis model in broiler chickens. In the first trial, four groups of chickens were fed a diet supplemented with butyric acid, with essential oils, with butyric acid in combination with medium-chain fatty acids, or with butyric acid in combination with medium-chain fatty acids and essential oils. In all groups except for the group receiving only butyric acid, a significant decrease in the number of birds with necrotic lesions was found compared with the infected, untreated control group. In the second trial the same products were tested but at a higher concentration. An additional group was fed a diet supplemented with only medium-chain fatty acids. In all groups except for that receiving butyric acid in combination with medium-chain fatty acids and essential oils, a significant decrease in the number of birds with necrotic lesions was found compared with the infected, untreated control group. These results suggest that butyric acid, medium-chain fatty acids and/or essential oils may contribute to the prevention of necrotic enteritis in broilers.

Volatile constituents of Dianthus rupicola Biv. from Sicily: activity against microorganisms affecting cellulosic objects.

PubMed

Casiglia, Simona; Bruno, Maurizio; Senatore, Felice

2014-01-01

Dianthus rupicola Biv. (cliffs carnation) is a camephytic, suffruticous, perennial plant growing up to 40 cm high. The plant is widespread in Sicily and neighbouring islands (Egadi, Lampedusa, Lipari) and in some areas of southern Italy. GC and GC-MS analyses of the essential oil distilled from the flowers showed the presence of 66 components. Its composition is characterised by the high content of thymol and carvacrol derivatives. A good antibacterial activity against Bacillus cereus and Bacillussubtilis, both infesting cellulosic historical material, was shown, whereas the antioxidant capacity was determined to be quite poor.

All roads lead to Rome: Towards understanding different avenues of tolerance to huanglongbing in citrus cultivars.

PubMed

Killiny, Nabil; Jones, Shelley E; Nehela, Yasser; Hijaz, Faraj; Dutt, Manjul; Gmitter, Frederick G; Grosser, Jude W

2018-05-18

Citrus tolerance to huanglongbing could result from tolerance to the pathogen Candidatus Liberibacter asiaticus (CLas) and/or to its vector Diaphorina citri. Field observations and greenhouse-controlled studies showed that some citrus cultivars were more tolerant than others. However, the mechanism(s) behind the tolerance has not been determined yet. Using GC-MS, we investigated the volatile organic compounds (VOCs) and the non-volatile metabolite profiles of two tolerant citrus cultivars- Australian finger lime, 'LB8-9' Sugar Belle ® mandarin hybrid, and a recently released mandarin hybrid 'Bingo'. The three were grafted onto the rootstock, Carrizo citrange. Our findings showed that the metabolomic profiles of Australian finger lime were different from that of 'LB8-9'. Finger lime was high in many amino acids and tricarboxylic acid intermediates, whereas 'LB8-9' was high in several amino acids, sugars, and sugar alcohols. 'LB8-9' was high in thymol, which is known for its strong antimicrobial activity against a panel of pathogenic bacteria. The metabolomic profiles of 'Bingo' were intensely different from the other mandarin hybrid, 'LB8-9', including a reduced thymol biosynthetic pathway and low amounts of most of the amino acids and sugar alcohols. Remarkably, 1,8-cineole (eucalyptol) was only detected in 'Bingo', indicating that eucalyptol could have feeding and ovipositional repellency against D. citri. The metabolite profiles generated for HLB-tolerant citrus species will improve the ability of citrus breeders and will allow them to take more informed decisions. Metabolomic profiling of HLB-tolerant citrus species could identify tolerance specific markers that can be introduced to other commercial citrus cultivars to improve their tolerance to HLB disease. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Study of two-stage ohmic hydro-extraction of essential oil from Artemisia aucheri Boiss.: Antioxidant and antimicrobial characteristics.

PubMed

Mojtahed Zadeh Asl, Rozita; Niakousari, Mehrdad; Hashemi Gahruie, Hadi; Saharkhiz, Mohammad Jamal; Mousavi Khaneghah, Amin

2018-05-01

The effect of two-stage ohmic-assisted hydrodistillation (TSOH) on the extraction and characteristics of essential oils (EOs) from the Artemisia aucheri Boiss. was studied, and the results were compared to conventional hydrodistillation (HD). According to the results, the yield of EOs obtained through TSOH was almost 30% higher than those extracted by HD in nearly one-quarter of a time used by the HD. Scanning electron micrographs of A. aucheri leaves showed almost complete eruption of EO glands and their surrounding area in TSOH extraction method, hence achieving higher yield. The components of the EOs obtained through TSOH were only slightly different from those of HD. GC/MS analysis indicated some differences in the quantity of the main components, too. The main components of EOs were identified as Thymol, Linalool, Geraniol, Camphor, and 1, 8-Cineole, Davana ether and Cis-Davanone. Thymol (~17%) and Cis-Davanone (~23%) were the highest quantity in the EOs extracted from TSOH and HD, respectively. The variation of antioxidant and antimicrobial activities of the EOs may be attributed to these differences in the percentage of the main components. The radical scavenging activity of the EOs obtained by TSOH was almost twice that of HD. Based on antimicrobial activity assays, the EOs were efficient against S. aureus (a Gram-positive), E. coli (a Gram-negative), and S. cerevisiae (yeast). However, the efficacy was higher in gram-positive than gram-negative bacteria and yeast. The results indicate TSOH has a potential to produce EOs from herbal plants at a faster rate, higher yield, being probably more efficient in terms of energy although having similar antimicrobial and antioxidant efficacy. Copyright © 2018 Elsevier Ltd. All rights reserved.

Are all phytochemicals useful in the preventing of DNA damage?

PubMed

Bacanlı, Merve; Aydın, Sevtap; Başaran, A Ahmet; Başaran, Nurşen

2017-11-01

Phytochemicals derived from natural plants have been used commonly for the prevention and/or treatment of different diseases due to the belief of their safety. Many plant species synthesize toxic chemicals. New natural chemicals are being discovered but their toxic effects are unknown. Phytochemicals have been regarded as possible antioxidants. But on the other hand it is suggested that various phenolic antioxidants can display pro-oxidant properties at high doses. In this review, the role of some phytochemicals (epigallocathecin gallate, carvacrol, galangin, limonene, lycopene, naringin, puerarin, terpinene, thymol and ursolic acid) on the prevention of DNA damage will be discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inhibitory effects of spices on growth and toxin production of toxigenic fungi.

PubMed Central

Hitokoto, H; Morozumi, S; Wauke, T; Sakai, S; Kurata, H

1980-01-01

The inhibitory effects of 29 commercial powdered spices on the growth and toxin production of three species of toxigenic Aspergillus were observed by introducing these materials into culture media for mycotoxin production. Of the 29 samples tested, cloves, star anise seeds, and allspice completely inhibited the fungal growth, whereas most of the others inhibited only the toxin production. Eugenol extracted from cloves and thymol from thyme caused complete inhibition of the growth of both Aspergillus flavus and Aspergillus versicolor at 0.4 mg/ml or less. At a concentration of 2 mg/ml, anethol extracted from star anise seeds inhibited the growth of all the strains. PMID:6769391

Effect of soil application of humic acid on nutrients uptake, essential oil and chemical compositions of garden thyme (Thymus vulgaris L.) under greenhouse conditions.

PubMed

Noroozisharaf, Alireza; Kaviani, Maryam

2018-05-01

Humic acid is natural biological organic, which has a high effect on plant growth and quality. However, the mechanisms of the promoting effect of humic acid on the volatile composition were rarely reported. In this study, the effects of soil application of humic acid on the chemical composition and nutrients uptake of Thymus vulgaris were investigated. Treatments comprised 0, 50, 75 and 100 g m -2 . Essential oil was extracted by hydrodistillation and analyzed using GC-MS and GC-FID. Essential oil content was enhanced by increase of the humic acid level and its content ranged from 0.8% (control) to 2.0% (75 g m -2 ). Thirty-two volatile compounds were identified and these compounds were considerably affected by humic acid. The highest percentage of thymol (74.15%), carvacrol (6.20%), p -cymene (4.24%), borneol (3.42%), trans -caryophyllene (1.70%) and cis -sabinene hydrate (1.35%) as major compounds were observed in T. vulgaris under 100 g m -2 humic acid. There was a linear relationship ( R 2  = 97%) between humic acid levels and thymol as a major compound. The oils were dominated by oxygenated monoterpenes followed by monoterpene hydrocarbons and sesquiterpene hydrocarbons. Based on the path coefficient analysis, the highest direct effects on essential oil content were observed in monoterpene esters (3.465) and oxygenated sesquiterpenes (3.146). The humic acid application also enhanced the uptake of N, P, K, Mg and Fe in garden thyme. The highest N (2.42%), P (0.75%), K (2.63%), Mg (0.23%) and Fe (1436.58 ppm) were observed in medium supplemented with 100 g m -2 humic acid. In all, the utilization of humic acid could positively change nutrients uptake, essential oil content and its major constituents in T. vulgaris .

Treatment With High-Hydrostatic Pressure, Activated Film Packaging With Thymol Plus Enterocin AS-48, and Its Combination Modify the Bacterial Communities of Refrigerated Sea Bream (Sparus aurata) Fillets

PubMed Central

Ortega Blázquez, Irene; Grande Burgos, María J.; Pérez-Pulido, Rubén; Gálvez, Antonio; Lucas, Rosario

2018-01-01

The aim of this study was to determine the impact of activated plastic films with thymol and enterocin AS-48 and high-hydrostatic pressure (HP) treatment on the bacterial load and bacterial diversity of vacuum-packaged sea bream fillets under refrigerated storage for 10 days. The activated film and the HP treatment reduced aerobic mesophiles viable counts by 1.46 and 2.36 log cycles, respectively, while the combined treatment achieved a reduction of 4.13 log cycles. HP and combined treatments resulted in longer delays in bacterial growth. Proteobacteria were the dominant phyla in sea bream fillets. The relative abundance of Firmicutes increased by the end of storage both in controls and in samples treated by HP singly or in combination with the activated films. The predominant operational taxonomic units (OTUs) found at time 0 in control samples (Listeria, Acinetobacter, Pseudomonas, Enterobacteriaceae, Chryseobacterium) rapidly changed during storage (with an increase of Vibrio, Photobacterium, and Shewanella together with Cloacibacterium and Lactobacillales by the end of storage). The activated film and the HP treatment induced drastic changes in bacterial diversity right after treatments (with Comamonadaceae, Methylobacterium, Acidovorax, and Sphingomonas as main OTUs) and also induced further modifications during storage. Bacterial diversity in activated film samples was quite homogeneous during storage (with Vibrio, Photobacterium, and Shewanella as main OTUs) and approached control samples. HP treatments (singly or in combination with activated films) determined a high relative abundance of Acinetobacter (followed by Pseudomonas and Shewanella) during early storage as well as a higher relative abundance of lactic acid bacteria by the end of storage. The results indicate that the complex dynamics of bacterial populations in the refrigerated sea bream fillets are markedly influenced by treatment and antimicrobials applied. PMID:29541064

Treatment With High-Hydrostatic Pressure, Activated Film Packaging With Thymol Plus Enterocin AS-48, and Its Combination Modify the Bacterial Communities of Refrigerated Sea Bream (Sparus aurata) Fillets.

PubMed

Ortega Blázquez, Irene; Grande Burgos, María J; Pérez-Pulido, Rubén; Gálvez, Antonio; Lucas, Rosario

2018-01-01

The aim of this study was to determine the impact of activated plastic films with thymol and enterocin AS-48 and high-hydrostatic pressure (HP) treatment on the bacterial load and bacterial diversity of vacuum-packaged sea bream fillets under refrigerated storage for 10 days. The activated film and the HP treatment reduced aerobic mesophiles viable counts by 1.46 and 2.36 log cycles, respectively, while the combined treatment achieved a reduction of 4.13 log cycles. HP and combined treatments resulted in longer delays in bacterial growth. Proteobacteria were the dominant phyla in sea bream fillets. The relative abundance of Firmicutes increased by the end of storage both in controls and in samples treated by HP singly or in combination with the activated films. The predominant operational taxonomic units (OTUs) found at time 0 in control samples ( Listeria, Acinetobacter, Pseudomonas, Enterobacteriaceae, Chryseobacterium ) rapidly changed during storage (with an increase of Vibrio, Photobacterium , and Shewanella together with Cloacibacterium and Lactobacillales by the end of storage). The activated film and the HP treatment induced drastic changes in bacterial diversity right after treatments (with Comamonadaceae, Methylobacterium, Acidovorax , and Sphingomonas as main OTUs) and also induced further modifications during storage. Bacterial diversity in activated film samples was quite homogeneous during storage (with Vibrio, Photobacterium , and Shewanella as main OTUs) and approached control samples. HP treatments (singly or in combination with activated films) determined a high relative abundance of Acinetobacter (followed by Pseudomonas and Shewanella ) during early storage as well as a higher relative abundance of lactic acid bacteria by the end of storage. The results indicate that the complex dynamics of bacterial populations in the refrigerated sea bream fillets are markedly influenced by treatment and antimicrobials applied.

Chemical composition of essential oils and in vitro antioxidant activity of fresh and dry leaves crude extracts of medicinal plant of Lactuca Sativa L. native to Sultanate of Oman.

PubMed

Al Nomaani, Rahma Said Salim; Hossain, Mohammad Amzad; Weli, Afaf Mohammed; Al-Riyami, Qasim; Al-Sabahi, Jamal Nasser

2013-05-01

To isolate and analyse the chemical composition in the essential oils and free radical scavenging activity of different crude extracts from the fresh and dry leaves of vegetable plants of Lactuca sativa L. (L. sativa). The essential oils and volatile chemical constituents were isolated from the fresh and dry leaves of L. sativa (lettuce) grown in Sultanate of Oman by hydro distillation method. The antioxidant activity of the crude extracts was carried out by well established free radical scavenging activity (DPPH) method. About 20 chemical compounds of different concentration representing 83.07% and 79.88% respectively were isolated and identified by gas chromatography-mass spectroscopy in the essential oils isolated from the fresh and dry leaves as α-pinene (5.11% and 4.05%), γ-cymene (2.07% and 1.92%), thymol (11.55% and 10.73%), durenol (52.00% and 49.79%), α-terpinene (1.66% and 1.34%), thymol acetate (0.99% and 0.67%), caryophyllene (2.11% and 1.98%), spathulenol (3.09% and 2.98%), camphene (4.11% and 3.65%), limonene (1.28% and 1.11%) representing these major chemical compounds. However, some other minor chemical constituents were also isolated and identified from the essential oil of lettuce including β-pinene, α-terpinolene, linalool, 4-terpineol, α-terpineol, o-methylthymol, L-alloaromadendrene and viridiflorene. The chemical constituents in the essential oils from the locally grown lettuce were identified in the following classes or groups of chemical compounds such as monoterpenes, sesquiterpenes volatile organic compounds and their oxygenated hydrocarbons. Therefore, the essential oils and the crude extracts from Omani vegetable species of lettuce are active candidates which would be used as antioxidant, antifungal or antimicrobial agents in new drugs preparation for therapy of infectious diseases.

Isolation and identification of antibacterial compounds from Thymus kotschyanus aerial parts and Dianthus caryophyllus flower buds.

PubMed

Mohammed, Muthanna J; Al-Bayati, Firas A

2009-06-01

The aerial parts of Thymus kotschyanus Boiss. and Hohen. (Lamiaceae) and flower buds of Dianthus caryophyllus L. (Caryophyllaceae) have been traditionally implemented in the treatment of wounds, throat and gum infections and gastro-intestinal disorder by the indigenous people of northern Iraq, although the compounds responsible for the medicinal properties have not been identified. In this study, antibacterial compounds from both plants were isolated and characterized, and the biological activity of each compound was assessed individually and combined. Compounds were isolated and characterized from the extracted essential oils of both plants using different spectral techniques: TLC, FTIR spectra and HPLC. The minimum inhibitory concentrations MIC values for the compounds were assessed individually and combined based on a microdilution and the checkerboard method in 96 multi-well microtiter plates. Two known compounds were isolated from the essential oils of both plants and were identified as thymol and eugenol. The isolated compounds were investigated for their single and combined antibacterial activities against seven selected pathogenic bacteria; Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Proteus mirabilis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Thymol MIC values ranged from 15.6 to 250.0 microg/ml and B. cereus was found to be the most sensitive pathogen with a MIC value of 15.6 microg/ml. Eugenol achieved stronger MIC values against most tested pathogens and the best MIC value (15.6 microg/ml) was observed against B. cereus, L. monocytogenes and K. pneumoniae whereas, S. aureus, P. mirabilis and E. coli were inhibited with a MIC value of 31.2 microg/ml. Combination results had antibacterial enhancement against most pathogens and the best synergistic result was seen against P. mirabilis and E. coli. The isolation of two antibacterial compounds from Thymus kotschyanus aerial parts and Dianthus caryophyllus flower buds validates the use of these species in the treatment of throat and gum infections, wound-healing and gastro-intestinal disorder.

Use of enhanced nisin derivatives in combination with food-grade oils or citric acid to control Cronobacter sakazakii and Escherichia coli O157:H7.

PubMed

Campion, Alicia; Morrissey, Ruth; Field, Des; Cotter, Paul D; Hill, Colin; Ross, R Paul

2017-08-01

Cronobacter sakazakii and Escherichia coli O157:H7 are well known food-borne pathogens that can cause severe disease. The identification of new alternatives to heating to control these pathogens in foods, while reducing the impact on organoleptic properties and nutritional value, is highly desirable. In this study, nisin and its bioengineered variants, nisin V and nisin S29A, are used alone, or in combination with plant essential oils (thymol, carvacrol and trans-cinnamaldehyde) or citric acid, with a view to controlling C. sakazakii and E. coli O157:H7 in laboratory-based assays and model food systems. The use of nisin variants (30 μM) with low concentrations of thymol (0.015%), carvacrol (0.03%) and trans-cinnamaldehyde (0.035%) resulted in extended lag phases of growth compared to those for corresponding nisin A-essential oil combinations. Furthermore, nisin variants (60 μM) used in combination with carvacrol (0.03%) significantly reduced viable counts of E. coli O157:H7 (3-log) and C. sakazakii (4-log) compared to nisin A-carvacrol treatment. Importantly, this increased effectiveness translated into food. More specifically, sub-inhibitory concentrations of nisin variants and carvacrol caused complete inactivation of E. coli O157:H7 in apple juice within 3 h at room temperature compared to that of the equivalent nisin A combination. Furthermore, combinations of commercial Nisaplin and the food additive citric acid reduced C. sakazakii numbers markedly in infant formula within the same 3 h period. These results highlight the potential benefits of combining nisin and variants thereof with carvacrol and/or citric acid for the inhibition of Gram negative food-borne pathogens. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microencapsulated sorbic acid and pure botanicals affect Salmonella Typhimurium shedding in pigs: a close-up look from weaning to slaughter in controlled and field conditions.

PubMed

Grilli, Ester; Foresti, Fabio; Tugnoli, Benedetta; Fustini, Mattia; Zanoni, Maria G; Pasquali, Paolo; Callaway, Todd R; Piva, Andrea; Alborali, Giovanni L

2015-10-01

The aim of this study was to assess the efficacy of a combination of sorbic acid, thymol, and carvacrol in reducing the prevalence and shedding level of Salmonella Typhimurium in pigs either in a controlled challenge environment or in a production setting. In the first study, 24 weaned piglets were separated in 4 isolation units (6 piglets/isolation unit). Each unit received either a basal diet (no treatment) or a microencapsulated mixture of sorbic acid, thymol, and carvacrol at 1, 2, or 5 g/kg of feed. After 21 d, pigs were orally challenged with 6 log10 colony-forming units of Salmonella Typhimurium. Blood samples and feces from rectal ampullae were collected every week. On d56 of the study, pigs were euthanized and necropsied to collect intestinal contents (jejunum through colon) and ileocecal lymph nodes. Samples were analyzed for Salmonella Typhimurium and serological analysis was also conducted. In the second study, an all-in-all-out multisite pig farm that was positive for monophasic Salmonella Typhimurium was followed throughout a production cycle from weaning to slaughter. Pigs received either a basal diet or the basal diet including 5 g/kg of the microencapsulated additive. Environmental, fecal, and blood samples were collected monthly, and cecal contents and ileocecal lymph nodes were collected at slaughter to isolate and enumerate Salmonella. The results indicate that the additive at 5 g/kg tended to reduce Salmonella fecal prevalence in both a controlled challenge (p=0.07) and in production conditions (p=0.03). Nevertheless, the additive did not reduce the number of pigs seropositive for Salmonella, nor it reduced the Salmonella prevalence at slaughter. The data indicate that these additives are not effective alone but must be used in conjunction with appropriate containment measures at lairage in order to prevent reinfection in pigs and to reduce the number of pigs carrying Salmonella entering the food chain.

Chemical composition of essential oils and in vitro antioxidant activity of fresh and dry leaves crude extracts of medicinal plant of Lactuca Sativa L. native to Sultanate of Oman

PubMed Central

Al Nomaani, Rahma Said Salim; Hossain, Mohammad Amzad; Weli, Afaf Mohammed; Al-Riyami, Qasim; Al-Sabahi, Jamal Nasser

2013-01-01

Objective To isolate and analyse the chemical composition in the essential oils and free radical scavenging activity of different crude extracts from the fresh and dry leaves of vegetable plants of Lactuca sativa L. (L. sativa). Methods The essential oils and volatile chemical constituents were isolated from the fresh and dry leaves of L. sativa (lettuce) grown in Sultanate of Oman by hydro distillation method. The antioxidant activity of the crude extracts was carried out by well established free radical scavenging activity (DPPH) method. Results About 20 chemical compounds of different concentration representing 83.07% and 79.88% respectively were isolated and identified by gas chromatography-mass spectroscopy in the essential oils isolated from the fresh and dry leaves as α-pinene (5.11% and 4.05%), γ-cymene (2.07% and 1.92%), thymol (11.55% and 10.73%), durenol (52.00% and 49.79%), α-terpinene (1.66% and 1.34%), thymol acetate (0.99% and 0.67%), caryophyllene (2.11% and 1.98%), spathulenol (3.09% and 2.98%), camphene (4.11% and 3.65%), limonene (1.28% and 1.11%) representing these major chemical compounds. However, some other minor chemical constituents were also isolated and identified from the essential oil of lettuce including β-pinene, α-terpinolene, linalool, 4-terpineol, α-terpineol, o-methylthymol, L-alloaromadendrene and viridiflorene. Conclusions The chemical constituents in the essential oils from the locally grown lettuce were identified in the following classes or groups of chemical compounds such as monoterpenes, sesquiterpenes volatile organic compounds and their oxygenated hydrocarbons. Therefore, the essential oils and the crude extracts from Omani vegetable species of lettuce are active candidates which would be used as antioxidant, antifungal or antimicrobial agents in new drugs preparation for therapy of infectious diseases. PMID:23646297

Citrus fruit extracts with carvacrol and thymol eliminated 7-log acid-adapted Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes: A potential of effective natural antibacterial agents.

PubMed

Chung, Doohyun; Cho, Tae Jin; Rhee, Min Suk

2018-05-01

Despite the widespread belief that citrus fruit extracts (CFEs) are microbiologically safe due to their acidity, limited bactericidal effect results in low applicability as antibacterial agent and outbreaks occurred by acid-adapted pathogens. Here, we examined the antibacterial effects of CFEs [lime (Citrus medica), lemon (Citrus limon), calamansi (Citrus microcarpa)] combined with essential oil components (EOCs; carvacrol and thymol) against non-acid-adapted/acid-adapted Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes under 22 °C for 5 min. CFEs (<20%) alone or small amounts of EOCs (2.0 mM; 0.032%) alone could not inactivate the target bacteria effectively. However, combined treatments exhibited marked synergy: CFE + EOCs eliminated all the bacteria (>6.9 log CFU/ml). Among the CFEs tested, the highest synergism was shown by calamansi, an exotic citrus fruit previously unrecognized as an antibacterial agent. Although acid-adaptation improved bacterial survival, calamansi (<20%) + EOCs (<0.032%) completely inactivated even the most resistant pathogen (E. coli O157:H7). Validation test also showed that all tested commercial juice products also eliminated acid-adapted pathogens when used with EOCs. Physicochemical analysis of tested CFEs (pH measurement and HPLC analysis of components) revealed that low pH and flavanone (hesperidin) did not contribute to the synergistic bactericidal effects. Rather, the high citric acid content is likely to contribute to the strong synergistic effect with EOCs by damaging susceptible bacterial membranes. Sensory scores for CFEs were not altered by addition of EOCs at concentrations up to 1.5 mM. This study provides new insight into the utility of CFEs with EOCs to improve not only the microbiological safety of food products containing CFEs but also their applicability as natural antibacterial complex. Copyright © 2018 Elsevier Ltd. All rights reserved.

Stability of human sera collected for clinical chemistry determinations

NASA Technical Reports Server (NTRS)

Townsend, F. M.

1969-01-01

Problems in collecting and shipping human sera for clinical chemical analyses affect their stability and require proper preservation methods. It is shown that glutamic pyruvate transaminase is very unstable and serum cannot be shipped unless the shipping time is carefully controlled and is less than two days under refrigeration. A limit of four days handling time and avoidance of light exposure are required in bilirubin testing of specimens. Addition of 11 mg of a 10 to 1 mixture of finely powdered sodium fluoride and thymol per ml of blood to preserve specimen stability en route to a central laboratory prevents glycolysis. A citrate buffer at pH 6.2 in serum to be tested for alkaline phosphatase lessens decline at room temperature.

The constituents of essential oil in leaves of Karaj accession of Trigonella foenum graecum.

PubMed

Riasat, Mehrnaz; Jafari, Ali Ashraf; Bahmanzadegan, Atefeh; Hatami, Ahmad; Zareiyan, Faraneh

2017-07-01

The chemical composition of the essential oils of Karaj accession of Trigonella foenum graecum leaves was detected by hydro-distillation and analysed by gas chromatography (GC-FID) and gas chromatography-mass spectroscopy (GC-MS) apparatuses for first time. Thirty-six compounds representing 95.3% of the total components were identified. The patterns of the main compounds were (2E)-Hexenal (26.61%), n-Hexadecanoic acid (10.14%) and (E)-b-Ionone (7.99%). Other notable constituents were Thymol (4.79%), 6,10,14-trimethyl-2-Pentadecanone (4.59%), Carvacrol (3.40%), (E)-Nerolidol (3.32%) and (2E,6Z)-Nonadienal (3.30%). (2E)-Hexenal was found as the most dominant component in this study.

Antibacterial effects of the essential oils of commonly consumed medicinal herbs using an in vitro model.

PubMed

Soković, Marina; Glamočlija, Jasmina; Marin, Petar D; Brkić, Dejan; van Griensven, Leo J L D

2010-10-27

The chemical composition and antibacterial activity of essential oils from 10 commonly consumed herbs: Citrus aurantium, C. limon, Lavandula angustifolia, Matricaria chamomilla, Mentha piperita, M. spicata, Ocimum basilicum, Origanum vulgare, Thymus vulgaris and Salvia officinalis have been determined. The antibacterial activity of these oils and their main components; i.e. camphor, carvacrol, 1,8-cineole, linalool, linalyl acetate, limonene, menthol, a-pinene, b-pinene, and thymol were assayed against the human pathogenic bacteria Bacillus subtilis, Enterobacter cloacae, Escherichia coli O157:H7, Micrococcus flavus, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella enteritidis, S. epidermidis, S. typhimurium, and Staphylococcus aureus. The highest and broadest activity was shown by O. vulgare oil. Carvacrol had the highest antibacterial activity among the tested components.

A method for reducing environmental pollution by using essential oils in rodent pest management program.

PubMed

Jokić, Goran; Blažić, Tanja; Đurović-Pejčev, Rada; Đorđević, Tijana; Đedović, Suzana; Vukša, Marina

2017-08-01

Strong-smelling plant extracts, such as essential oils, have a variety of feeding effects on mammals. Considering current concerns over long-term health issues and environmental effects of chemicals, plant-based products with repellent or antifungal activities may represent good solutions for improvement of rodent pest control programs. The present study was therefore focused on examining the effects of bergamot, lavender, and thyme essential oils as additional bait components on daily intakes of cereal-based baits by wild house mice. Lavender essential oil, containing linalool and linalyl acetate as main components, and thyme essential oil with a prevailing thymol component had no effects on house mice diet. Bergamot essential oil, whose main components were linalool, limonene, and linalyl acetate, showed a repellent effect on house mouse diet.

Carum copticum L.: A Herbal Medicine with Various Pharmacological Effects

PubMed Central

Boskabady, Mohammad Hossein; Alitaneh, Saeed; Alavinezhad, Azam

2014-01-01

Carum copticum L. commonly known as “Ajwain” is cultivated in many regions of the world including Iran and India, states of Gujarat and Rajasthan. Traditionally, C. copticum has been used in the past for various therapeutic effects including bloating, fatigue, diarrhea, abdominal tumors, abdominal pain, respiratory distress, and loss of appetite. It has other health benefits such as antifungal, antioxidant, antibacterial, antiparasitic, and hypolipidemic effects. This plant contains different important components such as carbohydrates, glucosides, saponins and phenolic compounds (carvacrol), volatile oils (thymol), terpiene, paracymene and beta-pinene, protein, fat, fiber, and minerals including calcium, phosphorus, iron, and nicotinic acid (niacin). In the previous studies, several pharmacological effects were shown for C. copticum. Therefore, in this paper, the pharmacological effects of the plant were reviewed. PMID:25089273

[Extraction and analysis of chemical components of essential oil in Thymus vulgaris of tissue culture].

PubMed

Li, Xiao-Dong; Yang, Li; Xu, Shi-Qian; Li, Jian-Guo; Cheng, Zhi-Hui; Dang, Jian-Zhang

2011-10-01

To extract the essential oils from the Seedlings, the Aseptic Seedlings and the Tissue Culture Seedlings of Thymus vulgaris and analyze their chemical components and the relative contents. The essential oils were extracted by steam distillation, the chemical components and the relative contents were identified and analyzed by gas chromatography-mass spectrometry (GC/MS) and peak area normalization method. The main chemical components of essential oil in these three samples had no significant difference, they all contained the main components of essential oil in Thymus vulgaris: Thymol, Carvacrol, o-Cymene, gamma-Terpinene, Caryophyllene et al. and only had a slight difference in the relative content. This study provides important theoretical foundation and data reference for further study on production of essential oil in thyme by tissue culture technology.

Developpement d'un film antibacterien ayant des proprietes de glissement pour une meilleure processabilite

NASA Astrophysics Data System (ADS)

Silverwood, Richard

Product safety is of crucial importance for the food industry. The challenge of food safety is evidenced by the number of food poisoning in Canada and worldwide. An outbreak of listeriosis in 2008, having put the safety of Canadians at risk, has motivated the revision of the strategy for food safety in Canada. In this context, a collaboration between two major industrial players in Quebec and École Polytechnique de Montréal was initiated. This collaboration is supported by the creation of the Research Chair for safe, smart and sustainable food. One of the many forefront projects of this research chair is to develop a package having a bactericidal effect. Many compounds are currently available for incorporation into a finished product. Zinc Omadine™ by ArchChemicals and Irgaguard™ by BASF are some examples of products that have proven themselves. However, the incorporation of a bactericidal agent in a product having a direct contact with food must meet certain safety criteria. Thus, an overview of various antibacterial agents is made in terms of their effectiveness and their potential use in packaging a food product. To date, no technology allows easy incorporation of an antibacterial agent in a polymer matrix. Antibacterial constituents of the mixture with the polymer melt will provide the simplicity pursued. We chose nano zinc oxide as the main antibacterial agent for its mode of action, its great potential for sustainability and its ability not to migrate out of the polyethylene polymer matrix. Moreover, the effect of trace element at very low concentrations is validated. To increase efficiency, good dispersion is achieved by adding a polyethylene with maleic anhydride grafted groups. The increase in antibacterial properties by this change has been proven. Although these films exhibit a marked bactericidal effect, a lack of persistence of the antibacterial effect was noticed. This is probably due to a rearrangement of the molecular structure on the surface. This rearrangement, due to the polar nature of particles, inhibits the antibacterial effect of the particles, causing them to migrate to a critical distance, outside their scope. Furthermore, we evaluated briefly some other antibacterial agents. Calcium oxide (CaO) demonstrated, although lower than ZnO, an interesting antibacterial potential. The specificity of the bactericidal for gram-positive bacteria for this variance. The addition of iron oxide (Fe2O3) did not, by its hydrophilic properties, increase the bactericidal properties of CaO, simply by mixing them. Also, the use of thymol (component of essential oil of thyme) was effective, even at very low doses. A question mark hangs, however, the sustainability of such an agent. Its use in conjunction with a compatibilizer could result in a much more persistent bactericidal effect, slowing the process of migrating to the film surface. This effect is reduced when the bactericidal thymol is mixed with ZnO in the polyethylene matrix. Finally, a tool for optimizing slip additives was developed. To do this, a correlation that links the absorbance in infrared spectroscopy (ATR reflection) to the surface concentration of the lubricant was developed. By using this correlation, also called master curve, and an infrared spectrometer to test an unknown film, it is possible to find the initial concentration of slip additive. These studies highlight the potential use of zinc oxide and thymol as efficient bactericidal agent for the food industry. This work represents the first effort to develop an antibacterial film, involving nanoscale metal oxides and a polymer matrix of polyolefin.

Assessment of carvacrol for control of avian aspergillosis in intratracheally challenged chickens in comparison to voriconazole with a reference on economic impact.

PubMed

Tartor, Y H; Hassan, F A M

2017-11-01

This study was designed to investigate the efficacy of essential oils as an alternative prophylaxis and treatment for avian aspergillosis. The in vitro susceptibility of Aspergillus fumigatus strains to antifungal drugs and carvacrol, thymol, eugenol, thymoquinone and cinnamon was determined using the macrodiffusion and microdilution methods. Carvacrol has antifungal activity in comparison to voriconazole (VCZ) (MIC 0·5, 0·25 μg ml -1 respectively). While cinnamon, euganol, thymol and thymoquinone displayed moderate to weak inhibitory activity. For the efficacy study, five groups of 10-day-old chicks (n = 48) were infected intratracheally either with A. fumigatus conidia or saline (negative control). Chicks in carvacrol prophylactic and treatment (CRPT) group were fed for 10 days beginning from hatch with carvacrol (200 mg kg -1 per diet) supplemented diets. VCZ (VCZT:20 mg kg -1 body weight (BW)), carvacrol treatment (CRT, CRPT) was started upon appearance of the first clinical signs and continued for 10 days. Birds were monitored for an additional 15 days following treatment. Fungal burden and therapeutic efficacy were assessed by survival, BW, quantitative (q) culture (CFU), quantitative real-time PCR (qPCR) and histopathological changes at several time points. Serum biochemical changes were also assessed. VCZT, CRPT, CRT in comparison to the sham-treated (SHAM) group have prolonged survival (87·5, 83·4, 79·2, 41·7% respectively). In VCZT and CRPT, a significant reduction in clinical signs, lesions, CFU and qPCR counts to the limit of detection were observed. CRPT has the lowest BW reduction, economic losses and significant low total cholesterol levels. Carvacrol has a promising potential to be used as a prophylactic and treatment against A. fumigatus. Prognosis of avian aspergillosis is often poor due to delayed diagnosis and treatment failure. However, the widespread uses of azole prophylaxis in birds are thought to be the major driver of azole resistance. These findings create a possibility to develop an effective drug-free alternative strategy for control of avian aspergillosis. © 2017 The Society for Applied Microbiology.

Chitin-Induced Airway Epithelial Cell Innate Immune Responses Are Inhibited by Carvacrol/Thymol

PubMed Central

Erle, David J.

2016-01-01

Chitin is produced in large amounts by fungi, insects, and other organisms and has been implicated in the pathogenesis of asthma. Airway epithelial cells are in direct contact with environmental particles and serve as the first line of defense against inhaled allergens and pathogens. The potential contributions of airway epithelial cells to chitin-induced asthma remain poorly understood. We hypothesized that chitin directly stimulates airway epithelial cells to release cytokines that promote type 2 immune responses and to induce expression of molecules which are important in innate immune responses. We found that chitin exposure rapidly induced the expression of three key type 2-promoting cytokines, IL-25, IL-33 and TSLP, in BEAS-2B transformed human bronchial epithelial cells and in A549 and H292 lung carcinoma cells. Chitin also induced the expression of the key pattern recognition receptors TLR2 and TLR4. Chitin induced the expression of miR-155, miR-146a and miR-21, each of which is known to up-regulate the expression of pro-inflammatory cytokines. Also the expression of SOCS1 and SHIP1 which are known targets of miR-155 was repressed by chitin treatment. The monoterpene phenol carvacrol (Car) and its isomer thymol (Thy) are found in herbal essential oils and have been shown to inhibit allergic inflammation in asthma models. We found that Car/Thy inhibited the effects of chitin on type 2-promoting cytokine release and on the expression of TLRs, SOCS1, SHIP1, and miRNAs. Car/Thy could also efficiently reduce the protein levels of TLR4, inhibit the increase in TLR2 protein levels in chitin plus Car/Thy-treated cells and increase the protein levels of SHIP1 and SOCS1, which are negative regulators of TLR-mediated inflammatory responses. We conclude that direct effects of chitin on airway epithelial cells are likely to contribute to allergic airway diseases like asthma, and that Car/Thy directly inhibits epithelial cell pro-inflammatory responses to chitin. PMID:27463381

Effects of pure plant secondary metabolites on methane production, rumen fermentation and rumen bacteria populations in vitro.

PubMed

Joch, M; Mrázek, J; Skřivanová, E; Čermák, L; Marounek, M

2018-04-29

In this study, the effects of seven pure plant secondary metabolites (PSMs) on rumen fermentation, methane (CH 4 ) production and rumen bacterial community composition were determined. Two in vitro trials were conducted. In trial 1, nine concentrations of 8-hydroxyquinoline, α-terpineol, camphor, bornyl acetate, α-pinene, thymoquinone and thymol were incubated on separate days using in vitro 24-hr batch incubations. All compounds tested demonstrated the ability to alter rumen fermentation parameters and decrease CH 4 production. However, effective concentrations differed among individual PSMs. The lowest concentrations that reduced (p < .05) CH 4 production were as follows: 8 mg/L of 8-hydroxyquinoline, 120 mg/L of thymoquinone, 240 mg/L of thymol and 480 mg/L of α-terpineol, camphor, bornyl acetate and α-pinene. These concentrations were selected for use in trial 2. In trial 2, PSMs were incubated in one run. Methane was decreased (p < .05) by all PSMs at selected concentrations. However, only 8-hydroxyquinoline, bornyl acetate and thymoquinone decreased (p < .05) CH 4 relative to volatile fatty acids (VFAs). Based on denaturing gradient gel electrophoresis analysis, different PSMs changed the composition of bacterial communities to different extents. As revealed by Ion Torrent sequencing, the effects of PSMs on relative abundance were most pronounced in the predominant families, especially in Lachnospiraceae, Succinivibrionaceae, Prevotellaceae, unclassified Clostridiales and Ruminococcaceae. The CH 4 production was correlated negatively (-.72; p < .05) with relative abundance of Succinivibrionaceae and positively with relative abundance of Ruminococcaceae (.86; p < .05). In summary, this study identified three pure PSMs (8hydroxyquinoline, bornyl acetate and thymoquinone) with potentially promising effects on rumen CH 4 production. The PSMs tested in this study demonstrated considerable impact on rumen bacterial communities even at the lowest concentrations that decreased CH 4 production. The findings from this study may help to elucidate how PSMs affect rumen bacterial fermentation. © 2018 Blackwell Verlag GmbH.

Metabolically speaking: Possible reasons behind the tolerance of 'Sugar Belle' mandarin hybrid to huanglongbing.

PubMed

Killiny, Nabil; Valim, Maria Filomena; Jones, Shelley E; Omar, Ahmad A; Hijaz, Faraj; Gmitter, Fred G; Grosser, Jude W

2017-07-01

Huanglongbing (HLB) is currently considered the most destructive disease of citrus. Since its spread to the Americas, HLB has killed millions of trees and caused a sharp decline in production in many citrus growing regions. With the continuous spread of HLB disease in Florida and worldwide, there is an urgent need for the development of commercial citrus cultivars with a strong tolerance to HLB. Interestingly, field observations showed that some of the recently released mandarin hybrids such as 'Sugar Belle' were tolerant to HLB. In this study, we investigated the volatile and non-volatile metabolites of greenhouse-grown 'Sugar Belle' mandarin and four of its ancestors in order to understand why 'Sugar Belle' mandarin is relatively tolerant to HLB. Leaf volatiles were directly extracted with hexane and analyzed using gas chromatography-mass spectrometry (GC-MS). Leaf polar metabolites were extracted with a mixture of methanol:water (1:1, v/v), derivatized to their trimethylsilyl ethers, and analyzed using GC-MS. Forty-seven volatile compounds and forty-two polar metabolites were detected in 'Sugar Belle' mandarin leaves and its ancestors. 'Sugar Belle' was high in several volatiles such as α-thujene, para-cymene, γ-terpinene, thymol, β-elemene, and (E)-β-caryophyllene. Some of these volatiles, especially thymol, β-elemene, and (E)-β-caryophyllene are known for their anti-microbial activity. In addition, 'Sugar Belle' mandarin was the highest in synephrine, benzoic acid, ferulic acid, caffeic acid, chiro-inositol, fructose, glucose, threonic acid, saccharic acid, and galactaric acid, and the second in threonine, malic acid, and myo-inositol compared to the ancestors. Phenolic compounds such as benzoic, ferulic, and caffeic acids may act as antibacterial agents, whereas others like sugar alcohols may protect 'Sugar Belle' mandarin from stress during pathogen attack. The tolerance of 'Sugar Belle' and other newly released mandarin hybrids should be further evaluated using greenhouse controlled studies. If tolerance of these hybrids is confirmed, they could be used to replace the traditionally susceptible cultivars. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Comparative pharmacology of flatworm and roundworm glutamate-gated chloride channels: Implications for potential anthelmintics.

PubMed

Lynagh, Timothy; Cromer, Brett A; Dufour, Vanessa; Laube, Bodo

2014-12-01

Pharmacological targeting of glutamate-gated chloride channels (GluCls) is a potent anthelmintic strategy, evidenced by macrocyclic lactones that eliminate numerous roundworm infections by activating roundworm GluCls. Given the recent identification of flatworm GluCls and the urgent need for drugs against schistosomiasis, flatworm GluCls should be evaluated as potential anthelmintic targets. This study sought to identify agonists or modulators of one such GluCl, SmGluCl-2 from the parasitic flatworm Schistosoma mansoni. The effects of nine glutamate-like compounds and three monoterpenoid ion channel modulators were measured by electrophysiology at SmGluCl-2 recombinantly expressed in Xenopus laevis oocytes. For comparison with an established anthelmintic target, experiments were also performed on the AVR-14B GluCl from the parasitic roundworm Haemonchus contortus. l-Glutamate was the most potent agonist at both GluCls, but l-2-aminoadipate, d-glutamate and d-2-aminoadipate activated SmGluCl-2 (EC50 1.0 ± 0.1 mM, 2.4 ± 0.4 mM, 3.6 ± 0.7 mM, respectively) more potently than AVR-14B. Quisqualate activated only SmGluCl-2 whereas l-aspartate activated only AVR-14B GluCls. Regarding the monoterpenoids, both GluCls were inhibited by propofol, thymol and menthol, SmGluCl-2 most potently by thymol (IC50 484 ± 85 μM) and least potently by menthol (IC50 > 3 mM). Computational docking suggested that agonist and inhibitor potency is attributable to particular interactions with extracellular or membrane-spanning amino acid residues. These results reveal that flatworm GluCls are pharmacologically susceptible to numerous agonists and modulators and indicate that changes to the glutamate γ-carboxyl or to the propofol 6-isopropyl group can alter the differential pharmacology at flatworm and roundworm GluCls. This should inform the development of more potent compounds and in turn lead to novel anthelmintics.

Coatings with a Mole-hill Structure of Nanoparticle-Raspberry Containers for Surfaces with Abrasion-Refreshable Reservoir Functionality.

PubMed

Ballweg, Thomas; Gellermann, Carsten; Mandel, Karl

2015-11-11

Active silica nanoparticle-based raspberry-like container depots for agents such as antimicrobial substances are presented. The nano raspberry-containers are integrated into coatings in a way that they form a mole-hill structure; i.e., they are partly standing out of the coating. As an application example, it is demonstrated that the containers can be filled with antimicrobially active agents such as nano ZnO or Ag or organic molecules such as thymol. It is demonstrated that the containers can be partly chopped-off via abrasion by rubbing over the surface. This mechanism proves to be an attractive approach to render surfaces refreshable. A first proof of principle for antimicrobial activity of the intact containers in the coatings and the abrasion treated, chopped-off (and thereby reactivated) containers is demonstrated.

Influence of Phenological Stages on Yield and Quality of Oregano (Origanum vulgare L.) Under the Agroclimatic Condition of Doon Valley (Uttarakhand)

PubMed Central

Chauhan, N. K.; Singh, S.; Haider, S. Z.; Lohani, H.

2013-01-01

A field experiment was conducted under the agroclimatic conditions of Doon valley, in order to determine the effects of phenological stages on herbage yield and quality of oil in oregano (Origanum vulgare L.). Plants were harvested in five phenological stages, i.e. early vegetative, late vegetative, flower initiation, full bloom, and fruit set stages. Results showed the significant effects of phenological stages on herbage, yield, and quality of oregano. Harvesting at full bloom stage showed better results in terms of herbage and oil yield. The quality of essential oil was evaluated using GC and GC/MS. Thymol content was rich in all the stages (46.90-62.26%) followed by γ-terpinene (1.11-11.75%) and p-cymene (3.11-5.32%). PMID:24302806

The construction and operation of a water tunnel in application to flow visualization studies of an oscillating airfoil

NASA Technical Reports Server (NTRS)

Olsen, J. H.; Liu, H. T.

1973-01-01

The water tunnel which was constructed at the NASA Ames Research Center is described along with the flow field adjacent to an oscillating airfoil. The design and operational procedures of the tunnel are described in detail. Hydrogen bubble and thymol blue techniques are used to visualize the flow field. Results of the flow visualizations are presented in a series of still pictures and a high speed movie. These results show that time stall is more complicated than simple shedding from the leading edge or the trailing edge, particularly at relatively low frequency oscillations comparable to those of a helicopter blade. Therefore, any successful theory for predicting the stall loads on the helicopter blades must treat an irregular separated region rather than a discrete vortex passing over each blade surface.

The role of flavor and fragrance chemicals in TRPA1 (transient receptor potential cation channel, member A1) activity associated with allergies.

PubMed

Mihara, Satoru; Shibamoto, Takayuki

2015-01-01

TRPA1 has been proposed to be associated with diverse sensory allergic reactions, including thermal (cold) nociception, hearing and allergic inflammatory conditions. Some naturally occurring compounds are known to activate TRPA1 by forming a Michael addition product with a cysteine residue of TRPA1 through covalent protein modification and, in consequence, to cause allergic reactions. The anti-allergic property of TRPA1 agonists may be due to the activation and subsequent desensitization of TRPA1 expressed in sensory neurons. In this review, naturally occurring TRPA1 antagonists, such as camphor, 1,8-cineole, menthol, borneol, fenchyl alcohol and 2-methylisoborneol, and TRPA1 agonists, including thymol, carvacrol, 1'S-1'- acetoxychavicol acetate, cinnamaldehyde, α-n-hexyl cinnamic aldehyde and thymoquinone as well as isothiocyanates and sulfides are discussed.

Validated Colorimetric Assay of Clonidine Hydrochloride from Pharmaceutical Preparations

PubMed Central

Corciova, Andreia

2016-01-01

Clonidine hydrochloride is an antihypertensive agent used for migraine prophylaxis, attention deficit hyperactivity disorder, menopausal flushing and Tourette syndrome. The quantity of the active substance in pharmaceutical preparations must be within specific limits, in agreement with the respective label claim. Therefore, the aim of this study was to establish the conditions for two spectrophotometric methods for clonidine determination, based on the formation of the ion pair complex between clonidine hydrochloride and thymol blue/bromophenol blue. A Jasco UV-Vis 530 spectrophotometer was used for the analysis and the maxim absorbance was measured at 418 nm/448 nm against blank solution. After validation, the methods were used for quantification of clonidine hydrochloride in two commercial samples (tablets). The recovery of active substance varies between 98.06 and 100.13 % without interferences from the excipients. PMID:27610155

Differential presence of anthropogenic compounds dissolved in the marine waters of Puget Sound, WA and Barkley Sound, BC.

PubMed

Keil, Richard; Salemme, Keri; Forrest, Brittany; Neibauer, Jaqui; Logsdon, Miles

2011-11-01

Organic compounds were evaluated in March 2010 at 22 stations in Barkley Sound, Vancouver Island Canada and at 66 locations in Puget Sound. Of 37 compounds, 15 were xenobiotics, 8 were determined to have an anthropogenic imprint over natural sources, and 13 were presumed to be of natural or mixed origin. The three most frequently detected compounds were salicyclic acid, vanillin and thymol. The three most abundant compounds were diethylhexyl phthalate (DEHP), ethyl vanillin and benzaldehyde (∼600 n g L(-1) on average). Concentrations of xenobiotics were 10-100 times higher in Puget Sound relative to Barkley Sound. Three compound couplets are used to illustrate the influence of human activity on marine waters; vanillin and ethyl vanillin, salicylic acid and acetylsalicylic acid, and cinnamaldehyde and cinnamic acid. Ratios indicate that anthropogenic activities are the predominant source of these chemicals in Puget Sound. Published by Elsevier Ltd.

Immunomodulatory effects of phytogenics in chickens and pigs — A review

PubMed Central

2018-01-01

Environmental stressors like pathogens and toxins may depress the animal immune system through invasion of the gastrointestinal tract (GIT) tract, where they may impair performance and production, as well as lead to increased mortality rates. Therefore, protection of the GIT tract and improving animal health are top priorities in animal production. Being natural-sourced materials, phytochemicals are potential feed additives possessing multiple functions, including: anti-inflammatory, anti-fungal, anti-viral and antioxidative properties. This paper focuses on immunity-related physiological parameters regulated by phytochemicals, such as carvacrol, cinnamaldehyde, curcumin, and thymol; many studies have proven that these phytochemicals can improve animal performance and production. On the molecular level, the impact of inflammatory gene expression on underlying mechanisms was also examined, as were the effects of environmental stimuli and phytochemicals in initiating nuclear factor kappa B and mitogen-activated protein kinases signaling pathways and improving health conditions. PMID:29268586

CLINICAL STUDIES ON KALMEGH (ANDROGRAPHIS PANICULATA NEES) IN INFECTIVE HEPATITIS

PubMed Central

Chturvedi, G. N.; Tomar, G. S.; Tiwari, S. K.; Singh, K. P.

1983-01-01

Infective hepatitis ia an acute inflamatory condition of liver. It is usually manifested in the form of Jaundice. In this clinical study Kalmegh(Andrographis paniculata Nees) was given in the decoction form to the patients of infective hepitis. The results were assessed on the basis of clinical and biochemical parameters. A marked symptomatic improvement in majority of the cases was observed. A statistically highly significant decrease was noted in various liver function tests viz., serum bilirubin, thymol turbidity, alkaline phosphatase, S.G.O.T.; S.G.P.T. and serum globulin fraction of protein. Moreover it increased significantly total serum globulin fraction of protien. Moreover it increased significantly total serum protein level along with albumin fraction. On the total assessment 80% cases of this series were cured and 20% patients were relieved. Therefore, Kalmegh appears to be a useful remedy for the treatment of infective hepatitis. PMID:22556984

Clinical studies on kalmegh (andrographis paniculata nees) in infective hepatitis.

PubMed

Chturvedi, G N; Tomar, G S; Tiwari, S K; Singh, K P

1983-04-01

Infective hepatitis ia an acute inflamatory condition of liver. It is usually manifested in the form of Jaundice. In this clinical study Kalmegh(Andrographis paniculata Nees) was given in the decoction form to the patients of infective hepitis. The results were assessed on the basis of clinical and biochemical parameters. A marked symptomatic improvement in majority of the cases was observed. A statistically highly significant decrease was noted in various liver function tests viz., serum bilirubin, thymol turbidity, alkaline phosphatase, S.G.O.T.; S.G.P.T. and serum globulin fraction of protein. Moreover it increased significantly total serum globulin fraction of protien. Moreover it increased significantly total serum protein level along with albumin fraction. On the total assessment 80% cases of this series were cured and 20% patients were relieved. Therefore, Kalmegh appears to be a useful remedy for the treatment of infective hepatitis.

Chemical Constituents of Essential Oil from Lippia sidoides Cham. (Verbenaceae) Leaves Cultivated in Hidrolândia, Goiás, Brazil

PubMed Central

de Morais, Sandra Ribeiro; Oliveira, Thiago Levi Silva; Bara, Maria Teresa Freitas; da Conceição, Edemilson Cardoso; Rezende, Maria Helena; Ferri, Pedro Henrique; de Paula, José Realino

2012-01-01

Several studies involving the family Verbenaceae, occurring in the Brazilian Cerrado, have emphasized the popular use of many aromatic species. We highlight the use of Lippia sidoides Cham., known as “alecrim pimenta,” native to northeastern Brazil and northern Minas Gerais. Leaves of this species were collected in antropized Brazilian Cerrado area, in Hidrolândia, Goiás, and their essential oils were extracted by hydrodistillation in a Clevenger-type apparatus and thereafter analyzed GC/MS. Among the compounds identified in this study were the most abundant oxygenated monoterpenes, followed by sesquiterpenes hydrocarbons. The oxygenated monoterpene 1,8-cineole was the major constituent followed by isoborneol and bornyl acetate. The chemical composition of essential oil described in this paper differs from that described in the literature for L. sidoides found in its native environment, where the major constituents are thymol and carvacrol. PMID:22505916

Composition of the essential oils of three Uzbek Scutellaria species (Lamiaceae) and their antioxidant activities.

PubMed

Mamadalieva, Nilufar Zokirjonovna; Sharopov, Farukh; Satyal, Prabodh; Azimova, Shahnoz Sadykovna; Wink, Michael

2017-05-01

The chemical composition of the essential oils obtained from aerial parts of Scutellaria immaculata Nevski ex Juz., Scutellaria ramosissima M. Pop. and Scutellaria schachristanica Juz. (Lamiaceae) growing wild in Uzbekistan was analysed by GC and GC-MS. The main constituents of the essential oils from S. immaculata were acetophenone (30.39%), eugenol (20.61%), thymol (10.04%) and linalool (6.92%), whereas constituents of the essential oils fromS. schachristanica were acetophenone (34.74%), linalool (26.98%) and eugenol (20.67%). The S. ramosissima oil is dominated by germacrene D (23.96%), β-caryophyllene (11.09%), linalool (9.63%) and hexadecanoic acid (8.34%). The essential oils of Scutellaria species exhibited weaker antioxidant effects in DPPH, ABTS and FRAP assays. In FRAP assay, only eugenol exhibited a substantial reducing power IC 50  = 2476.92 ± 15.8 (mM Fe(II)/g).

Chemical composition and antibacterial activity of Origanum saccatum P.H. Davis essential oil obtained by solvent-free microwave extraction: comparison with hydrodistillation.

PubMed

Sozmen, Fazli; Uysal, Burcu; Oksal, Birsen S; Kose, Elif Odabas; Deniz, I Gokhan

2011-01-01

The components of the essential oils (EOs) obtained by solvent-free microwave extraction (SFME) and hydrodistillation (HD) from endemic Origanum saccatum P.H. Davis were identified by using GC/MS. The main constituents of both EOs obtained by SFME and HD, respectively, from O. saccatum were p-cymene (72.5 and 70.6%), thymol (9.32 and 8.11%), and carvacrol (7.18 and 6.36%). The EO obtained by SFME contained substantially higher amounts of oxygenated compounds and lower amounts of monoterpenes than did the EO obtained by HD. The antibacterial activities of the EOs obtained by SFME and HD were evaluated with the disc diffusion method by comparison with 10 different bacterial strains. The antibacterial activity of the EO extracted by SFME was found to be more effective than that of the EO extracted by HD against seven of the tested bacteria.

A detailed study of the volatile components of Plectranthus asirensis of Saudi Arabian origin.

PubMed

Al-Saleem, Muneera S M; Khan, Merajuddin; Alkhathlan, Hamad Z

2016-10-01

Essential oil composition of Plectranthus asirensis grown in Saudi Arabia was chemically analysed for the first time by various gas chromatography techniques (GC-MS, GC-FID, Co-GC, LRI determination and database and literature searches) using two different stationary phase columns (polar and nonpolar). This analysis led to the characterisation of a total of 124 components representing 98.5% of the total oil composition. The results revealed that P. asirensis oil was mainly dominated by monoterpenoids (90.7%) in which most representative constituents were thymol (66.0 ± 0.36%), γ-terpinene (14.0 ± 0.18%), p-cymene (5.2 ± 0.06%) and β-caryophyllene (3.0 ± 0.03%). It is worth mentioning here that this is the first report on the phytochemical constituents of P. asirensis.

Rapid evaluation and quantitative analysis of thyme, origano and chamomile essential oils by ATR-IR and NIR spectroscopy

NASA Astrophysics Data System (ADS)

Schulz, Hartwig; Quilitzsch, Rolf; Krüger, Hans

2003-12-01

The essential oils obtained from various chemotypes of thyme, origano and chamomile species were studied by ATR/FT-IR as well as NIR spectroscopy. Application of multivariate statistics (PCA, PLS) in conjunction with analytical reference data leads to very good IR and NIR calibration results. For the main essential oil components (e.g. carvacrol, thymol, γ-terpinene, α-bisabolol and β-farnesene) standard errors are in the range of the applied GC reference method. In most cases the multiple coefficients of determination ( R2) are >0.97. Using the IR fingerprint region (900-1400 cm -1) a qualitative discrimination of the individual chemotypes is possible already by visual judgement without to apply any chemometric algorithms.The described rapid and non-destructive methods can be applied in industry to control very easily purifying, blending and redistillation processes of the mentioned essential oils.

Essential Oil Composition of Phagnalon sordidum (L.) from Corsica, Chemical Variability and Antimicrobial Activity.

PubMed

Brunel, Marion; Vitrac, Caroline; Costa, Jean; Mzali, Fatima; Vitrac, Xavier; Muselli, Alain

2016-03-01

The chemical composition of Phagnalon sordidum (L.) essential oil was investigated for the first time using gas chromatography and chromatography/mass spectrometry. Seventy-six compounds, which accounted for 87.9% of the total amount, were identified in a collective essential oil of P. sordidum from Corsica. The main essential oil components were (E)-β-caryophyllene (14.4%), β-pinene (11.0%), thymol (9.0%), and hexadecanoic acid (5.3%). The chemical compositions of essential oils from 19 Corsican locations were investigated. The study of the chemical variability using statistical analysis allowed identifying direct correlation between the three populations of P. sordidum widespread in Corsica and the essential oil compositions they produce. The in vitro antimicrobial activity of P. sordidum essential oil was evaluated and it exhibited a notable activity on a large panel of clinically significant microorganisms. © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

Phytochemical composition and in vitro screening of the antimicrobial activity of essential oils on oral pathogenic bacteria.

PubMed

Tardugno, Roberta; Pellati, Federica; Iseppi, Ramona; Bondi, Moreno; Bruzzesi, Giacomo; Benvenuti, Stefania

2018-03-01

In this study, the activity of essential oils (EOs) against microorganisms involved in oral diseases was evaluated. Fourteen EOs were selected and subjected to gas chromatographic analysis, including Illicium verum, Eucaliptus globulus, Eugenia caryophyllata, Leptospermum scoparium, Mentha arvensis, Mentha piperita, Myrtus communis, Salvia officinalis, Melaleuca alternifolia, Rosmarinus officinalis, Lavandula x intermedia, Thymus capitatus and Thymus vulgaris. These EOs were tested for their antimicrobial activity on Streptococcus mutans and Lactobacillus species clinically isolated from dental surgery patients. The antibacterial activity was evaluated by means of the disc diffusion and the minimum inhibitory concentration (MIC). Five EOs, having shown an interesting antimicrobial activity, were selected for a second screening in combination between them and with chlorhexidine. From the second assays, two EO-EO and three EO-chlorhexidine associations gave interesting results as potential constituents of mouthwashes, especially for the contribution of oxygenated monoterpenes, including menthol, thymol and carvacrol.

Antimocrobial Polymer

DOEpatents

McDonald, William F.; Huang, Zhi-Heng; Wright, Stacy C.

2005-09-06

A polymeric composition having antimicrobial properties and a process for rendering the surface of a substrate antimicrobial are disclosed. The composition comprises a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, (ii) an antimicrobial agent selected from quaternary ammonium compounds, gentian violet compounds, substituted or unsubstituted phenols, biguanide compounds, iodine compounds, and mixtures thereof, and (iii) a crosslinking agent containing functional groups capable of reacting with the amino groups. In one embodiment, the polymer is a polyamide formed from a maleic anhydride or maleic acid ester monomer and alkylamines thereby producing a polyamide having amino substituted alkyl chains on one side of the polyamide backbone; the crosslinking agent is a phosphine having the general formula (A)3P wherein A is hydroxyalkyl; and the antimicrobial agent is chlorhexidine, dimethylchlorophenol, cetyl pyridinium chloride, gentian violet, triclosan, thymol, iodine, and mixtures thereof.

Semisynthetic Phenol Derivatives Obtained from Natural Phenols: Antimicrobial Activity and Molecular Properties.

PubMed

Pinheiro, Patrícia Fontes; Menini, Luciana Alves Parreira; Bernardes, Patrícia Campos; Saraiva, Sérgio Henriques; Carneiro, José Walkimar Mesquita; Costa, Adilson Vidal; Arruda, Társila Rodrigues; Lage, Mateus Ribeiro; Gonçalves, Patrícia Martins; Bernardes, Carolina de Oliveira; Alvarenga, Elson Santiago; Menini, Luciano

2018-01-10

Semisynthetic phenol derivatives were obtained from the natural phenols: thymol, carvacrol, eugenol, and guaiacol through catalytic oxychlorination, Williamson synthesis, and aromatic Claisen rearrangement. The compounds characterization was carried out by 1 H NMR, 13 C NMR, and mass spectrometry. The natural phenols and their semisynthetic derivatives were tested for their antimicrobial activity against the bacteria: Staphylococcus aureus, Escherichia coli, Listeria innocua, Pseudomonas aeruginosa, Salmonella enterica Typhimurium, Salmonella enterica ssp. enterica, and Bacillus cereus. Minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values were determined using concentrations from 220 to 3.44 μg mL -1 . Most of the tested compounds presented MIC values ≤220 μg mL -1 for all the bacteria used in the assays. The molecular properties of the compounds were computed with the PM6 method. Through principle components analysis, the natural phenols and their semisynthetic derivatives with higher antimicrobial potential were grouped.

Lippia origanoides chemotype differentiation based on essential oil GC-MS and principal component analysis.

PubMed

Stashenko, Elena E; Martínez, Jairo R; Ruíz, Carlos A; Arias, Ginna; Durán, Camilo; Salgar, William; Cala, Mónica

2010-01-01

Chromatographic (GC/flame ionization detection, GC/MS) and statistical analyses were applied to the study of essential oils and extracts obtained from flowers, leaves, and stems of Lippia origanoides plants, growing wild in different Colombian regions. Retention indices, mass spectra, and standard substances were used in the identification of 139 substances detected in these essential oils and extracts. Principal component analysis allowed L. origanoides classification into three chemotypes, characterized according to their essential oil major components. Alpha- and beta-phellandrenes, p-cymene, and limonene distinguished chemotype A; carvacrol and thymol were the distinctive major components of chemotypes B and C, respectively. Pinocembrin (5,7-dihydroxyflavanone) was found in L. origanoides chemotype A supercritical fluid (CO(2)) extract at a concentration of 0.83+/-0.03 mg/g of dry plant material, which makes this plant an interesting source of an important bioactive flavanone with diverse potential applications in cosmetic, food, and pharmaceutical products.

Liquid and vapour-phase antifungal activities of essential oils against Candida albicans and non-albicans Candida.

PubMed

Mandras, Narcisa; Nostro, Antonia; Roana, Janira; Scalas, Daniela; Banche, Giuliana; Ghisetti, Valeria; Del Re, Simonetta; Fucale, Giacomo; Cuffini, Anna Maria; Tullio, Vivian

2016-08-30

The management of Candida infections faces many problems, such as a limited number of antifungal drugs, toxicity, resistance of Candida to commonly antifungal drugs, relapse of Candida infections, and the high cost of antifungal drugs. Though azole antifungal agents and derivatives continue to dominate as drugs of choice against Candida infections, there are many available data referring to the anticandidal activity of essential oils. Since we have previous observed a good antimicrobial activity of some essential oils against filamentous fungi, the aim of this study was to extend the research to evaluate the activity of the same oils on Candida albicans, C.glabrata and C.tropicalis clinical strains, as well as the effects of related components. Essential oils selection was based both on ethnomedicinal use and on proved antibacterial and/or antifungal activity of some of these oils. Fluconazole and voriconazole were used as reference drugs. The minimum inhibitory concentration (MIC) and the minimal fungicidal concentration (MFC) of essential oils (thyme red, fennel, clove, pine, sage, lemon balm, and lavender) and their major components were investigated by the broth microdilution method (BM) and the vapour contact assay (VC). Using BM, pine oil showed the best activity against all strains tested, though C.albicans was more susceptible than C.glabrata and C.tropicalis (MIC50-MIC90 = 0.06 %, v/v). On the contrary, sage oil displayed a weak activity (MIC50-MIC90 = 1 %, v/v). Thyme red oil (MIC50-MIC90 ≤ 0.0038 %, v/v for C.albicans and C.tropicalis, and 0.0078- < 0.015 %, v/v for C.glabrata), followed by lemon balm, lavender and sage were the most effective by VC. Carvacrol and thymol showed the highest activity, whereas linalyl acetate showed the lowest activity both by two methods. α-pinene displayed a better activity by BM than VC. Results show a good activity of essential oils, mainly thymus red and pine oils, and their components carvacrol, thymol and α-pinene against Candida spp., including fluconazole/voriconazole resistant strains. These data encourage adequately controlled and randomized clinical investigations. The use in vapour phase could have additional advantages without requiring direct contact, resulting in easy of environmental application such as in hospital, and/or in school.

Investigating Chemical Composition and Indications of Hydrosol Soft Drinks (Aromatic Waters) Used in Persian Folk Medicine for Women’s Hormonal and Reproductive Health Conditions

PubMed Central

Hamedi, Azadeh; Afifi, Mehdi; Etemadfard, Hamed

2017-01-01

Hydrosol soft drinks in Persian nutrition culture are produced as side products of the essential oil industry to be used as safe remedies for treatment of some ailments. This study investigated hydrosols for women’s hormonal health conditions. Detailed information was gathered by questionnaires. Chemical constituents of these mono- or poly-herbal hydrosols were identified after liquid/liquid extraction and gas chromatography–mass spectrometry. Hierarchical cluster and K-means analysis (SPSS software) were used to find their relevance. A literature survey was also performed. In most cases, thymol, carvacrol, and carvone were the major constituents except for dill, white horehound, willow, Moderr, and yarrow hydrosols, whose their major components were dill ether, menthol, phenethyl alcohol, linalool, or camphor. Based on clustering methods, some similarities could be found in their constituents with some exceptions. None of them have been studied scientifically before. These investigations may lead to the development of some functional drinks or even new lead components. PMID:28701045

Survival of honey bee (Hymenoptera: Apidae) spermatozoa incubated at room temperature from drones exposed to miticides.

PubMed

Burley, Lisa M; Fell, Richard D; Saacke, Richard G

2008-08-01

We conducted research to examine the potential impacts ofcoumaphos, fluvalinate, and Apilife VAR (Thymol) on drone honey bee, Apis mellifera L. (Hymenoptera: Apidae), sperm viability over time. Drones were reared in colonies that had been treated with each miticide by using the dose recommended on the label. Drones from each miticide treatment were collected, and semen samples were pooled. The pooled samples from each treatment were subdivided and analyzed for periods of up to 6 wk. Random samples were taken from each treatment (n = 6 pools) over the 6-wk period. Sperm viability was measured using dual-fluorescent staining techniques. The exposure of drones to coumaphos during development and sexual maturation significantly reduced sperm viability for all 6 wk. Sperm viability significantly decreased from the initial sample to week 1 in control colonies, and a significant decrease in sperm viability was observed from week 5 to week 6 in all treatments and control. The potential impacts of these results on queen performance and failure are discussed.

Water Deficit and Seasonality Study on Essential Oil Constituents of Lippia gracilis Schauer Germplasm

PubMed Central

Cruz, Elizangela Mércia de Oliveira; Pinto, Jéssika Andreza Oliveira; Fontes, Saymo Santos; Arrigoni-Blank, Maria de Fátima; Bacci, Leandro; de Jesus, Hugo César Ramos; Santos, Darlisson de Alexandria; Alves, Péricles Barreto; Blank, Arie Fitzgerald

2014-01-01

The aim of this study was to analyze the chemical composition of the essential oil from leaves of Lippia gracilis genotypes, in the dry and rainy seasons, and with and without irrigation. The extraction of essential oil was realized by hydrodistillation in a Clevenger apparatus. The chemical composition analysis was performed using a GC-MS/FID. The leaves of the L. gracilis genotypes provide essential oil with content between 1.25% and 1.92% in the rainy season and 1.42% and 2.70% in the dry season; when irrigation was used the content was between 1.42% and 2.87%, without irrigation contents were between 1.60% and 3.00%. The chemical composition of L. gracilis showed high levels of terpenes. The major constituent of genotypes LGRA-106 was thymol and carvacrol was the major constituent for the other genotypes. Concentrations showed little variation between seasons, demonstrating the stability of the chemical composition of L. gracilis even with different climatic conditions. PMID:25302321

[Inhibition of oxidation of unsaturated fatty acid methyl esters by essential oils].

PubMed

Misharina, T A; Alinkina, E S; Vorobjeva, A K; Terenina, M B; Krikunova, N I

2016-01-01

The essential oils from 16 various spice plants were studied as natural antioxidants for the inhibition of autooxidation of polyunsaturated fatty acids methyl esters isolated from linseed oil. The content of methyl oleate, methyl linoleate, and methyl linolenoate after 1, 2, and 4 months of autooxidation were used as criteria to estimate the antioxidant efficiencies of essential oils. In 4 months, 92% of the methyl linolenoate and 79% of the methyl linoleate were oxidized in a control sample of a model system. It was found that the most effective antioxidants were essential oils from clove bud, cinnamon leaves, and oregano. They inhibited autooxidation of methyl linolenoate by 76–85%. The antioxidant properties of these essential oils were due to phenols— eugenol, carvacrol, and thymol. Essential oil from coriander did not contain phenols, but it inhibited methyl linolenoate oxidation by 38%. Essential oils from thyme, savory, mace, lemon, and tea tree inhibited methyl linolenoate oxidation by 17–24%. The other essential oils had no antioxidant properties.

GC-MS characterisation and antibacterial activity evaluation of Nigella sativa oil against diverse strains of Salmonella.

PubMed

Sarwar, Arslan; Latif, Zakia

2015-01-01

Salmonella resistance is becoming a worldwide serious health issue in these days; therefore, it is an urgent need to develop some alternative approaches to overcome this problem. Twenty bacterial strains were isolated and purified from different environmental sources and confirmed as Salmonella by morphological and biochemical analyses. Further confirmation was done by 16s rRNA sequencing. Antibiotic susceptibility test was performed by well diffusion assay against different concentrations of Ceftriaxone and Ciprofloxacin. The behaviour of both antibiotics was different against diverse strains of Salmonella. Salmonella strains resistant to both antibiotics were analysed for antibacterial activity of natural extracts of Nigella sativa (black seeds). N. sativa oil was found to be more effective against Salmonella species for which even Ceftriaxone and Ciprofloxacin were ineffective. Gas chromatography and mass spectrometry analysis of N. sativa oil was also accomplished, exhibiting 10 compounds including thymoquinone, p-cymene, cis-carveol, thymol, α-phellandrene, α-pinene, β-pinene, trans-anethole, α-longipinene and longifolene.

Induction of Fatty Acid Composition Modifications and Tolerance to Biocides in Salmonella enterica Serovar Typhimurium by Plant-Derived Terpenes▿

PubMed Central

Dubois-Brissonnet, Florence; Naïtali, Murielle; Mafu, Akier Assanta; Briandet, Romain

2011-01-01

To enhance food safety and stability, the food industry tends to use natural antimicrobials such as plant-derived compounds as an attractive alternative to chemical preservatives. Nonetheless, caution must be exercised in light of the potential for bacterial adaptation to these molecules, a phenomenon previously observed with other antimicrobials. The aim of this study was to characterize the adaptation of Salmonella enterica serovar Typhimurium to sublethal concentrations of four terpenes extracted from aromatic plants: thymol, carvacrol, citral, and eugenol, or combinations thereof. Bacterial adaptation in these conditions was demonstrated by changes in membrane fatty acid composition showing (i) limitation of the cyclization of unsaturated fatty acids to cyclopropane fatty acids when cells entered the stationary phase and (ii) bacterial membrane saturation. Furthermore, we demonstrated an increased cell resistance to the bactericidal activity of two biocides (peracetic acid and didecyl dimethyl ammonium bromide). The implications of membrane modifications in terms of hindering the penetration of antimicrobials through the bacterial membrane are discussed. PMID:21131520

Does antioxidant properties of the main component of essential oil reflect its antioxidant properties? The comparison of antioxidant properties of essential oils and their main components.

PubMed

Dawidowicz, Andrzej L; Olszowy, Małgorzata

2014-01-01

This study discusses the similarities and differences between the antioxidant activities of some essential oils: thyme (Thymus vulgaris), basil (Ocimum basilicum), peppermint (Mentha piperita), clove (Caryophyllus aromaticus), summer savory (Satureja hortensis), sage (Salvia hispanica) and lemon (Citrus limon (L.) Burm.) and of their main components (thymol or estragole or menthol or eugenol or carvacrol or camphor or limonene) estimated by using 2,2'-Diphenyl-1-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and β-carotene bleaching assays. The obtained data show that the antioxidant properties of essential oil do not always depend on the antioxidant activity of its main component, and that they can be modulated by their other components. The conclusions concerning the interaction of essential oil components depend on the type of method applied for assessing the antioxidant activity. When comparing the antioxidant properties of essential oils and their main components, the concepts of synergism, antagonism and additivity are very relevant.

Antibacterial activities of plant-derived compounds and essential oils toward Cronobacter sakazakii and Cronobacter malonaticus.

PubMed

Fraňková, Adéla; Marounek, Milan; Mozrová, Věra; Weber, Jaroslav; Klouček, Pavel; Lukešová, Daniela

2014-10-01

Cronobacter sakazakii and C. malonaticus are opportunistic pathogens that cause infections in children and immunocompromised adults. In the present study, the antibacterial activity of 19 plant-derived compounds, 5 essential oils, and an extract of propolis were assessed against C. sakazakii and C. malonaticus. The effects of most of these antimicrobials have not been reported previously. Both strains were susceptible to thymol, carvacrol, thymoquinone, p-cymene, linalool, camphor, citral, eugenol, and trans-cinnamaldehyde as well as cinnamon, lemongrass, oregano, clove, and laurel essential oils; their minimum inhibitory concentrations varied between 0.1 and 2.0 mg/mL. As an alternative treatment method, vapors of the volatiles were tested as an indirect treatment. Vapors of trans-cinnamaldehyde, eugenol, oregano, and cinnamon essential oils inhibited both tested strains, while vapors of linalool were only active against C. sakazakii. To our knowledge, this study is the first time that the inhibitory activity of the vapors of these compounds and essential oils has been reported against Cronobacter spp.

Comparative study of the chemical profiling, antioxidant and antimicrobial activities of essential oils of different parts of Thymus willdenowii Boiss & Reut.

PubMed

Ouknin, Mohamed; Romane, Abderrahmane; Costa, Jean; Majidi, Lhou

2018-02-27

The analysis of Thymus willdenowii Boiss & Reut essential oils (TW EOs) shows 33 components accounting for (96.3-97.7%) of all identified. The main constituents of TW EOs were thymol (35.5-47.3%), p-cymene (13.9-23.8%), γ-terpinene (8.9-20.3%). The antioxidant assays revealed that all TW EOs tested showed strong activities, the antimicrobial effect of TW EOs has been tested against isolated clinical strains of Proteus mirabilis (ATCC 35659), Escherichia coli (ATCC 25922), Candida albicans (ATCC 10231), Bacillus cereus (ATCC 10876), and Aspergillus brasilliensis (ATCC 16404). The antimicrobial test indicates that TW EOs show an inhibition effect against all the tested bacteria with a MIC of 6.9 to 27.6 μg/mL -1 . These results proving that the essential oils extracted from Thymus willdenowii Boiss & Reut may be a new potential source of natural antimicrobial applied in pharmaceutical and food industries.

Larvicidal activity of essential oils extracted from commonly used herbs in Lebanon against the seaside mosquito, Ochlerotatus caspius.

PubMed

Knio, K M; Usta, J; Dagher, S; Zournajian, H; Kreydiyyeh, S

2008-03-01

This study investigates the potential of essential oils from commonly used medical and culinary herbs in Lebanon as an environmentally safe measure to control the seaside mosquito, Ochlerotatus caspius. The composition of essential oils extracted from parsley seeds and leaves, alpine thyme inflorescences, anis seeds, and coriander fruits were analyzed by GC-MS, and the major components of these oils were found to be thymol, sabinene, carvacrol, anethole, and linalool, respectively. Mosquito larvicidal assays were conducted to evaluate the LC(50) and LC(90) after 24 and 48h of the essential oils and their major constituents. All of the tested oils proved to have strong larvicidal activity (LC(50): 15-156ppm) against Oc. caspius fourth instars, with the most potent oil being thyme inflorescence extract, followed by parsley seed oil, aniseed oil, and then coriander fruit oil. Toxicity of each oil major constituent was also estimated and compared to a reported larvicidal compound, eugenol.

The first report on mushroom green mould disease in Croatia.

PubMed

Hatvani, Lóránt; Sabolić, Petra; Kocsubé, Sándor; Kredics, László; Czifra, Dorina; Vágvölgyi, Csaba; Kaliterna, Joško; Ivić, Dario; Đermić, Edyta; Kosalec, Ivan

2012-12-01

Green mould disease, caused by Trichoderma species, is a severe problem for mushroom growers worldwide, including Croatia. Trichoderma strains were isolated from green mould-affected Agaricus bisporus (button or common mushroom) compost and Pleurotus ostreatus (oyster mushroom) substrate samples collected from Croatian mushroom farms. The causal agents of green mould disease in the oyster mushroom were T. pleurotum and T. pleuroticola, similar to other countries. At the same time, the pathogen of A. bisporus was exclusively the species T. harzianum, which is different from earlier findings and indicates that the range of mushroom pathogens is widening. The temperature profiles of the isolates and their hosts overlapped, thus no range was found that would allow optimal growth of the mushrooms without mould contamination. Ferulic acid and certain phenolic compounds, such as thymol showed remarkable fungistatic effect on the Trichoderma isolates, but inhibited the host mushrooms as well. However, commercial fungicides prochloraz and carbendazim were effective agents for pest management. This is the first report on green mould disease of cultivated mushrooms in Croatia.

C15078. Essential oil composition of Phagnalon sordidum (L.) from Corsica, chemical variability and antimicrobial activity.

PubMed

Brunel, Marion; Vitrac, Caroline; Costa, Jean; Mzali, Fatima; Vitrac, Xavier; Muselli, Alain

2016-02-10

The chemical composition of Phagnalon sordidum (L.) essential oil was investigated for the first time using gas chromatography and chromatography-mass spectrometry. Seventy-six compounds, which accounted for 87.9% of the total amount, were identified in a collective essential oil of P. sordidum from Corsica. The main essential oil components were (E)-β-caryophyllene (14.4%), β-pinene (11.0%), thymol (9.0%), and hexadecanoic acid (5.3%). The chemical compositions of essential oils from 19 Corsican locations were investigated. The study of the chemical variability using statistical analysis allowed identifying direct correlation between the three populations of P. sordidum widespread in Corsica and the essential oil compositions they produce. The in vitro antimicrobial activity of P. sordidum essential oil was evaluated and exhibited a notable activity on a large panel of clinically significant microorganisms. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Antibacterial and antioxidant activities of essential oils isolated from Thymbra capitata L. (Cav.) andOriganum vulgare L.

PubMed

Faleiro, Leonor; Miguel, Graça; Gomes, Sónia; Costa, Ludmila; Venâncio, Florencia; Teixeira, Adriano; Figueiredo, A Cristina; Barroso, José G; Pedro, Luis G

2005-10-19

Antilisterial activities of Thymbra capitata and Origanum vulgare essential oils were tested against 41 strains of Listeria monocytogenes. The oil of T. capitata was mainly constituted by one component, carvacrol (79%), whereas for O. vulgare three components constituted 70% of the oil, namely, thymol (33%), gamma-terpinene (26%), and p-cymene (11%). T. capitata essential oil had a significantly higher antilisterial activity in comparison to O. vulgare oil and chloramphenicol. No significant differences in L. monocytogenes susceptibilities to the essential oils tested were registered. The minimum inhibitory concentration values of T. capitata essential oil and of carvacrol were quite similar, ranging between 0.05 and 0.2 microL/mL. Antioxidant activity was also tested, the essential oil of T. capitata showing significantly higher antioxidant activity than that of O. vulgare. Use of T. capitata and O. vulgare essential oils can constitute a powerful tool in the control of L. monocytogenes in food and other industries.

Investigating Chemical Composition and Indications of Hydrosol Soft Drinks (Aromatic Waters) Used in Persian Folk Medicine for Women's Hormonal and Reproductive Health Conditions.

PubMed

Hamedi, Azadeh; Afifi, Mehdi; Etemadfard, Hamed

2017-10-01

Hydrosol soft drinks in Persian nutrition culture are produced as side products of the essential oil industry to be used as safe remedies for treatment of some ailments. This study investigated hydrosols for women's hormonal health conditions. Detailed information was gathered by questionnaires. Chemical constituents of these mono- or poly-herbal hydrosols were identified after liquid/liquid extraction and gas chromatography-mass spectrometry. Hierarchical cluster and K-means analysis (SPSS software) were used to find their relevance. A literature survey was also performed. In most cases, thymol, carvacrol, and carvone were the major constituents except for dill, white horehound, willow, Moderr, and yarrow hydrosols, whose their major components were dill ether, menthol, phenethyl alcohol, linalool, or camphor. Based on clustering methods, some similarities could be found in their constituents with some exceptions. None of them have been studied scientifically before. These investigations may lead to the development of some functional drinks or even new lead components.

Antimicrobial, antioxidant, and anti-inflammatory activities of essential oils from five selected herbs.

PubMed

Tsai, Mei-Lin; Lin, Chih-Chien; Lin, Wei-Chao; Yang, Chao-Hsun

2011-01-01

Eucalyptus bridgesiana, Cymbopogon martinii, Thymus vulgaris, Lindernia anagallis, and Pelargonium fragrans are five species of herbs used in Asia. Their essential oils were analyzed by GC-MS, and a total of 36 components were detected. The results of our study indicated that, except for the essential oil of P. fragrans, all of the essential oils demonstrated obvious antimicrobial activity against a broad range of microorganisms. The C. martinii essential oil, which is rich in geraniol, was the most effective antimicrobial additive. All of the essential oils demonstrated antioxidant activities on 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, β-carotene/linoleic acid assay, and nitric oxide radical scavenging assay. Furthermore, the T. vulgaris essential oil, which possesses plentiful thymol, exhibited the highest antioxidant activity. For P. acnes-induced secretion of pro-inflammatory cytokines, the essential oils of P. aeruginosa, C. martinii, and T. vulgaris reduced the TNF-α, IL-1β, and IL-8 secretion levels of THP-1 cells.

Bactericidal activity of glutaraldehyde-like compounds from olive products.

PubMed

Medina, Eduardo; Brenes, Manuel; García, Aranzazu; Romero, Concepción; de Castro, Antonio

2009-12-01

The bactericidal effects of several olive compounds (nonenal, oleuropein, tyrosol, the dialdehydic form of decarboxymethyl elenolic acid either free [EDA] or linked to tyrosol [TyEDA] or to hydroxytyrosol [HyEDA]), other food phenolic compounds (catechin, epicatechin, eugenol, thymol, carvacrol, and carnosic acid), and commercial disinfectants (glutaraldehyde [GTA] and ortho-phthalaldehyde [OPA]), were tested against strains of Pseudomonas fluorescens, Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. It was found that the bactericidal activities of olive GTA-like compounds (EDA, HyEDA, and TyEDA) were greater than those exerted by several food phenolic substances. Surprisingly, these olive antimicrobials were as active as the synthetic biocides GTA and OPA against the four bacteria studied. Thus, it has been proposed that the bactericidal activity of the main olive antimicrobials is primarily due to their dialdehydic structure, which is similar to that of the commercial biocides GTA and OPA. Our results clearly reveal that olive GTA-like compounds possess a strong bactericidal activity even greater than that of other food phenolic compounds or synthetic biocides.

The additive properties of Oxygen Radical Absorbance Capacity (ORAC) assay: the case of essential oils.

PubMed

Bentayeb, Karim; Vera, Paula; Rubio, Carlos; Nerín, Cristina

2014-04-01

The ORAC assay is applied to measure the antioxidant capacity of foods or dietary supplements. Sometimes, the manufacturers claim antioxidant capacities that may not correspond to the constituents of the product. These statements are sheltered by the general understanding that antioxidants might exhibit synergistic properties, but this is not necessarily true when dealing with ORAC assay values. This contribution applies the ORAC assay to measure the antioxidant capacity of ten essential oils typically added to foodstuffs: citronella, dill, basil, red thyme, thyme, rosemary, oregano, clove and cinnamon. The major components of these essential oils were twenty-one chemicals in total. After a preliminary discrimination, the antioxidant capacity of eugenol, carvacrol, thymol, α-pinene, limonene and linalool was determined. The results showed that 72-115% of the antioxidant capacity of the essential oils corresponded to the addition of the antioxidant capacity of their constituents. Thus, the ORAC assay showed additive properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

An Overview on Indications and Chemical Composition of Aromatic Waters (Hydrosols) as Functional Beverages in Persian Nutrition Culture and Folk Medicine for Hyperlipidemia and Cardiovascular Conditions

PubMed Central

Hamedi, Azadeh; Moheimani, Seyed Mahmoud; Sakhteman, Amirhossein; Etemadfard, Hamed; Moein, Mahmoodreza

2017-01-01

Hydrosol beverages in Persian nutrition culture and ethnomedicine are the side products of essential oil industry that are used as delicious drinks or safe remedies. To investigate indications and chemical composition of hydrosol beverages for hyperlipidemia and cardiovascular conditions, Fars province was selected as the field of study. Ethnomedical data were gathered by questionnaires. The constituents of hydrosols were extracted with liquid/liquid extraction and analyzed by gas chromatography–mass spectrometry. Statistical analysis were used to cluster their constituents and find the relevance of their composition. A literature survey was also performed on plants used to prepare them. Thymol was the major or second major component of these beverages, except for wormwood and olive leaf hydrosols. Based on clustering methods, although some similarities could be found, composition of barberry, will fumitory, dill, and aloe hydrosols have more differences than others. These studies may help in developing some functional beverages or new therapeutics. PMID:29228785

Thymol and Carvacrol Affect Hybrid Tilapia through the Combination of Direct Stimulation and an Intestinal Microbiota-Mediated Effect: Insights from a Germ-Free Zebrafish Model.

PubMed

Ran, Chao; Hu, Jun; Liu, Wenshu; Liu, Zhi; He, Suxu; Dan, Bui Chau Truc; Diem, Nguyen Ngoc; Ooi, Ei Lin; Zhou, Zhigang

2016-05-01

Essential oils (EOs) are commonly used as animal feed additives. Information is lacking on the mechanisms driving the beneficial effects of EOs in animals, especially the role played by the intestinal microbiota of the host. The purpose of this study was to clarify the relative contribution of direct effects of EOs on the physiology and immune system of tilapia and indirect effects mediated by the intestinal microbiota by using a germ-free zebrafish model. Juvenile hybrid tilapia were fed a control diet or 1 of 4 treatment diets containing 60-800 mg Next Enhance 150 (NE) (an EO product containing equal levels of thymol and carvacrol)/kg for 6 wk. The key humoral and cellular innate immune parameters were evaluated after the feeding period. In another experiment, the gut microbiota of tilapia fed a control or an NE diet (200 mg/kg) for 2 wk were transferred to 3-d postfertilization (dpf) germ-free (GF) zebrafish, and the expression of genes involved in innate immunity and tight junctions was evaluated in zebrafish at 6 dpf. Lastly, NE was directly applied to 3-dpf GF zebrafish at 3 doses ranging from 0.2 to 20 mg/L, and the direct effect of NE on zebrafish was evaluated after 1 and 3 d. NE supplementation at 200 mg/kg enhanced phagocytosis activity of head kidney macrophages (×1.36) (P < 0.05) and plasma lysozyme activity (×1.69) of tilapia compared with the control (P < 0.001), indicating an immunostimulatory effect. Compared with those colonized with control microbiota, GF zebrafish colonized with NE microbiota showed attenuated induction of immune response marker genes serum amyloid a (Saa; ×0.62), interleukin 1β (Il1β; ×0.29), and interleukin 8 (Il8; ×0.62) (P < 0.05). NE treatment of GF zebrafish at 2 and 20 mg/L for 1 d upregulated the expression of Il1β (×2.44) and Claudin1 (×1.38), respectively (P < 0.05), whereas at day 3 the expression of Occludin2 was higher (×3.30) in the 0.2-mg NE/L group compared with the GF control (P < 0.05). NE may affect the immunity of tilapia through a combination of factors, i.e., primarily through a direct effect on host tissue (immune-stimulating) but also an indirect effect mediated by microbial changes (immune-relieving). © 2016 American Society for Nutrition.

Repellent Activity of Apiaceae Plant Essential Oils and their Constituents Against Adult German Cockroaches.

PubMed

Lee, Hyo-Rim; Kim, Gil-Hah; Choi, Won-Sil; Park, Il-Kwon

2017-04-01

We evaluated the repellent activity of 12 Apiaceae plant essential oils and their components against male and female adult German cockroaches, Blattella germanica L., to find new natural repellents. Of all the plant essential oils tested, ajowan (Trachyspermum ammi Sprague) and dill (Anethum graveolens L.) essential oils showed the most potent repellent activity against male and female adult German cockroaches. Repellent activities of chemicals already identified in active oils were also investigated. Of the compounds identified, carvacrol, thymol, and R-(-)-carvone showed >80% repellent activity against male and female adult German cockroaches at 2.5 µg/cm2. S-(+)-Carvone, (+)-dihydrocarvone, and terpinen-4-ol showed >70% repellent activity against male and female adult German cockroaches at 10 µg/cm2. Our results indicated that Apiaceae plant essential oils and their constituents have good potential as natural repellents against adult German cockroaches. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Selective separation of furfural and hydroxymethylfurfural from an aqueous solution using a supported hydrophobic deep eutectic solvent liquid membrane.

PubMed

Dietz, Carin H J T; Kroon, Maaike C; Di Stefano, Michela; van Sint Annaland, Martin; Gallucci, Fausto

2017-12-14

For the first time, 12 different supported deep eutectic solvent (DES) liquid membranes were prepared and characterized. These membranes consist of a polymeric support impregnated with a hydrophobic DES. First, the different membranes were characterized and their stability in water and air was determined. Subsequently, the supported DES liquid membranes were applied for the recovery of furfural (FF) and hydroxymethylfurfural (HMF) from aqueous solutions. The effects of substrate properties (e.g. pore size), DES properties (e.g. viscosity) and concentrations of FF and HMF in the feed phase on the observed diffusivities and permeabilities were assessed. It was found that the addition of DES enhances the transport of FF and HMF through the polymeric membrane support. In particular, the use of the DES consisting of thymol + lidocaine (in the molar ratio 2 : 1) impregnated in a polyethylene support resulted in enhanced transport for both FF and HMF, and is most interesting for (in situ) isolation of FF and HMF from aqueous solutions, e.g. in biorefinery processes.

Chemical composition and biological activity of the essential oil of Origanum vulgare ssp. hirtum from different areas in the Southern Apennines (Italy).

PubMed

Mancini, Emilia; Camele, Ippolito; Elshafie, Hazem S; De Martino, Laura; Pellegrino, Carlo; Grulova, Daniela; De Feo, Vincenzo

2014-04-01

The chemical composition of the essential oils of Origanum vulgare ssp. hirtum, growing wild in three different localities in the Southern Apennines, was studied by GC-FID and GC/MS analyses. In total, 103 compounds were identified. The oils were mainly composed of phenolic compounds and all oils belonged to the chemotype carvacrol/thymol. The three essential oils were evaluated for their in vitro phytotoxic activity by determining their influence on the germination and initial radicle elongation of Sinapis arvensis L., Phalaris canariensis L., Lepidium sativum L., and Raphanus sativus L. The seed germination and radicle growth were affected in various degrees. Moreover, the antifungal activity of the three essential oils was assayed against three species causing pre- and postharvest fruit decay (Monilinia laxa, M. fructigena, and M. fructicola). At 1000 ppm, the three oils completely inhibited fungal growth. The hemolytic activity of the oils was assayed and showed no effect on the cell membranes of bovine erythrocytes. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

Composition and antimicrobial activities of Lippia multiflora Moldenke, Mentha x piperita L. and Ocimum basilicum L. essential oils and their major monoterpene alcohols alone and in combination.

PubMed

Bassolé, Imaël Henri Nestor; Lamien-Meda, Aline; Bayala, Balé; Tirogo, Souleymane; Franz, Chlodwig; Novak, Johannes; Nebié, Roger Charles; Dicko, Mamoudou Hama

2010-11-03

Essential oils from leaves of Lippia multiflora, Mentha x piperita and Ocimum basilicum from Burkina Faso were analysed by GC-FID and GC-MS. Major components were p-cymene, thymol, b-caryophyllene, carvacrol and carvone for L. multiflora, menthol and iso-menthone for M. x piperita and, linalool and eugenol for O. basilicum. The essential oils and their major monoterpene alcohols were tested against nine bacterial strains using the disc diffusion and broth microdilution methods. The essential oils with high phenolic contents were the most effective antimicrobials. The checkerboard method was used to quantify the efficacy of paired combinations of essential oils and their major components. The best synergetic effects among essential oils and major components were obtained with combinations involving O. basilicum essential oil and eugenol, respectively. As phenolic components are characterized by a strong spicy aroma, this study suggests that the selection of certain combinations of EOs could help to reduce the amount of essential oils and consequently reduce any adverse sensory impact in food.

Role of direct bioautographic method for detection of antistaphylococcal activity of essential oils.

PubMed

Horváth, Györgyi; Jámbor, Noémi; Kocsis, Erika; Böszörményi, Andrea; Lemberkovics, Eva; Héthelyi, Eva; Kovács, Krisztina; Kocsis, Béla

2011-09-01

The aim of the present study was the chemical characterization of some traditionally used and therapeutically relevant essential oils (thyme, eucalyptus, cinnamon bark, clove, and tea tree) and the optimized microbiological investigation of the effect of these oils on clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA). The chemical composition of the oils was analyzed by TLC, and controlled by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The antibacterial effect was investigated using a TLC-bioautographic method. Antibacterial activity of thyme, clove and cinnamon oils, as well as their main components (thymol, carvacrol, eugenol, and cinnamic aldehyde) was observed against all the bacterial strains used in this study. The essential oils of eucalyptus and tea tree showed weak activity in the bioautographic system. On the whole, the antibacterial activity of the essential oils could be related to their most abundant components, but the effect of the minor components should also be taken into consideration. Direct bioautography is more cost-effective and better in comparison with traditional microbiological laboratory methods (e.g. disc-diffusion, agar-plate technique).

Effect of active edible coatings made by basil seed gum and thymol on oil uptake and oxidation in shrimp during deep-fat frying.

PubMed

Khazaei, Naimeh; Esmaiili, Mohsen; Emam-Djomeh, Zahra

2016-02-10

The effect of active coating treatments on oil uptake, moisture loss, lipid oxidation, texture, color, and sensory evaluation of shrimp after deep-fat frying process was investigated. Compared with the uncoated samples, coating treatments decreased the oil uptake and moisture loss of fried shrimp by 34.50 and 13.9%, respectively. Fried shrimp samples were analyzed for peroxide value (PV) and thiobarbituric acid (TBA). The most reduction in lipid oxidation (46.4% for PV and 40.8% for TBA) was observed when shrimp samples were coated with CS4 (containing 10% thyme), while the control samples had the highest values of PV and TBA after deep-fat frying process. Coated fried samples had significantly lower toughness and stiffness than control samples (P<0.05). In terms of sensory evaluation, there was no significant difference in color, smell, and taste among the treatments (P>0.05). However, for the texture, juiciness, chewiness, and overall acceptability, coated fried samples had higher scores than control. Copyright © 2015 Elsevier Ltd. All rights reserved.

Response of Biomass Development, Essential Oil, and Composition of Plectranthus amboinicus (Lour.) Spreng. to Irrigation Frequency and Harvest Time.

PubMed

Sabra, Ali S; Astatkie, Tessema; Alataway, Abed; Mahmoud, Abeer A; Gendy, Ahmed S H; Said-Al Ahl, Hussein A H; Tkachenko, Kirill G

2018-03-01

A greenhouse experiment was conducted to study the effects of four irrigation intervals (4, 8, 12, and 16 days) and six harvests (2, 4, 6, 8, 10, and 12 months after transplanting) on biomass, essential oil content, and composition of Plectranthus amboinicus (Lour.) Spreng. Fresh weight and essential oil yield decreased with increasing irrigation interval; whereas, essential oil content was stimulated by water stress and increased as the irrigation interval increased. Fresh weight of Plectranthus amboinicus irrigated every 4 days peaked when harvested at 6 months, but essential oil content peaked when irrigated every 16 days and harvested at 2 months after transplantation. On the other hand, essential oil yield peaked when irrigated every 8 days and harvested at 6 months. Thymol, p-cymene, γ-terpinene, and β-caryophyllene were the major compounds, and they peaked at different irrigation intervals and harvest times. This study showed biomass, essential oil content, and yield as well as the major and minor constituents of Plectranthus amboinicus are influenced by irrigation interval and the timing of harvest. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

Composition, Cytotoxic and Antimicrobial Activities of Satureja intermedia C.A.Mey Essential Oil.

PubMed

Sharifi-Rad, Javad; Sharifi-Rad, Mehdi; Hoseini-Alfatemi, Seyedeh Mahsan; Iriti, Marcello; Sharifi-Rad, Majid; Sharifi-Rad, Marzieh

2015-08-03

In this study, the essential oil (EO) constituents from the aerial parts of Satureja intermedia C.A.Mey were detected by GC and GC/MS. The antimicrobial activity of EO on oral pathogens and its cytotoxicity to human cancer cells were determined by the microbroth dilution method and the crystal violet staining method, respectively. Thirty-nine compounds were identified and the main EO constituents were γ-terpinene (37.1%), thymol (30.2%), p-cymene (16.2%), limonene (3.9%), α-terpinene (3.3%), myrcene (2.5%), germacrene B (1.4%), elemicine (1.1%) and carvacrol (0.5%). The S. intermedia EO showed a concentration-dependent decrease in viability of Hep-G2 (hepatocellular carcinoma) and MCF-7 (breast adenocarcinoma) human cancer cell lines (p < 0.05). Antimicrobial screening of S. intermedia EO demonstrated slight antibacterial and antifungal activities against Streptococcus mutants, S. salivarius, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and C. glabrata. Further preclinical studies are needed to assess the efficacy and safety of S. intermedia EO as a new promising anticancer agent.

Composition, Cytotoxic and Antimicrobial Activities of Satureja intermedia C.A.Mey Essential Oil

PubMed Central

Sharifi-Rad, Javad; Sharifi-Rad, Mehdi; Hoseini-Alfatemi, Seyedeh Mahsan; Iriti, Marcello; Sharifi-Rad, Majid; Sharifi-Rad, Marzieh

2015-01-01

In this study, the essential oil (EO) constituents from the aerial parts of Satureja intermedia C.A.Mey were detected by GC and GC/MS. The antimicrobial activity of EO on oral pathogens and its cytotoxicity to human cancer cells were determined by the microbroth dilution method and the crystal violet staining method, respectively. Thirty-nine compounds were identified and the main EO constituents were γ-terpinene (37.1%), thymol (30.2%), p-cymene (16.2%), limonene (3.9%), α-terpinene (3.3%), myrcene (2.5%), germacrene B (1.4%), elemicine (1.1%) and carvacrol (0.5%). The S. intermedia EO showed a concentration-dependent decrease in viability of Hep-G2 (hepatocellular carcinoma) and MCF-7 (breast adenocarcinoma) human cancer cell lines (p < 0.05). Antimicrobial screening of S. intermedia EO demonstrated slight antibacterial and antifungal activities against Streptococcus mutants, S. salivarius, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and C. glabrata. Further preclinical studies are needed to assess the efficacy and safety of S. intermedia EO as a new promising anticancer agent. PMID:26247936

The properties of chitosan and gelatin films incorporated with ethanolic red grape seed extract and Ziziphora clinopodioides essential oil as biodegradable materials for active food packaging.

PubMed

Shahbazi, Yasser

2017-06-01

The aim of this study was to improve different characteristics including antibacterial, antioxidant, physical and mechanical properties of chitosan (Ch) and gelatin (Ge) films by incorporating Ziziphora clinopodioides essential oil (ZEO; 0 and 1% v/w) and ethanolic grape seed extract (GSE; 0 and 1% v/w). The main compounds of the ZEO were carvacrol (65.22%) and thymol (19.51%). According to our findings, addition of aforementioned materials could improve total phenolic content, antibacterial and antioxidant activities, thickness and also water vapor barrier property. ZEO and GSE reduces swelling index, tensile strength, puncture force and puncture deformation of Ch and Ge films. Pure Ch and Ge films had slightly yellow and white appearances, respectively, while films incorporated with GSE in combination with ZEO had grey appearances. This study indicated the some benefits of addition of ZEO and GSE into Ch and Ge films and their potentials for application as biodegradable active packaging. Copyright © 2017 Elsevier B.V. All rights reserved.

The Formation and Spatiotemporal Progress of the pH Wave Induced by the Temperature Gradient in the Thin-Layer H2O2-Na2S2O3-H2SO4-CuSO4 Dynamical System.

PubMed

Jędrusiak, Mikołaj; Orlik, Marek

2016-03-31

The H2O2-S2O3(2-)-H(+)-Cu(2+) dynamical system exhibits sustained oscillations under flow conditions but reveals only a single initial peak of the indicator electrode potential and pH variation under batch isothermal conditions. Thus, in the latter case, there is no possibility of the coupling of the oscillations and diffusion which could lead to formation of sustained spatiotemporal patterns in this process. However, in the inhomogeneous temperature field, due to dependence of the local reaction kinetics on temperature, spatial inhomogeneities of pH distribution can develop which, in the presence of an appropriate indicator, thymol blue, manifest themselves as the color front traveling along the quasi-one-dimensional reactor. In this work, we describe the experimental conditions under which the above-mentioned phenomena can be observed and present their numerical model based on thermokinetic coupling and spatial coordinate introduced to earlier isothermal homogeneous kinetic mechanism.

Antimicrobial activity of five essential oils from lamiaceae against multidrug-resistant Staphylococcus aureus.

PubMed

Kot, Barbara; Wierzchowska, Kamila; Piechota, Małgorzata; Czerniewicz, Paweł; Chrzanowski, Grzegorz

2018-06-11

Analysis of Lamiaceae essential oils (EOs) by GC-FID-MS revealed the presence as the major constituents of linalool (16.8%), linalyl acetate (15.7%) in Lavandula angustifolia, menthol (29.0%), menthone (22.7%), menthyl acetate (19.2%) in Mentha x piperita, terpinen-4-ol (27.1%), (E)-sabinene hydrate (12.1%), γ-terpinene (10.0%) in Origanum majorana, α-thujone (19.5%), camphor (19.0%), viridiflorol (13.5%) in Salvia officinalis, thymol (61.9%), p-cymene (10.0%), γ-terpinene (10.0%) in Thymus vulgaris. Based on the MIC and MBC values (0.09-0.78 mg/mL) and ratio MBC/MIC showed that EO from T. vulgaris (TO) had the strong inhibitory and bactericidal effect against multidrug-resistant Staphylococcus aureus. The bacterial cells were total killed by TO at 2MIC concentration after 6 h. The higher concentrations of other EOs were needed to achieve bactericidal effects. The strong bactericidal effect of TO against these bacteria indicates the possibility of topical use of TO but it requires research under clinical conditions.

Commercial Origanum compactum Benth. and Cinnamomum zeylanicum Blume essential oils against natural mycoflora in Valencia rice.

PubMed

Santamarina, M Pilar; Roselló, Josefa; Sempere, Francisca; Giménez, Silvia; Blázquez, M Amparo

2015-01-01

Chemical composition of commercial Origanum compactum and Cinnamomum zeylanicum essential oils and the antifungal activity against pathogenic fungi isolated from Mediterranean rice grains have been investigated. Sixty-one compounds accounting for more than 99.5% of the total essential oil were identified by using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Carvacrol (43.26%), thymol (21.64%) and their biogenetic precursors p-cymene (13.95%) and γ-terpinene (11.28%) were the main compounds in oregano essential oil, while the phenylpropanoids, eugenol (62.75%), eugenol acetate (16.36%) and (E)-cinnamyl acetate (6.65%) were found in cinnamon essential oil. Both essential oils at 300 μg/mL showed antifungal activity against all tested strains. O. compactum essential oil showed the best antifungal activity towards Fusarium species and Bipolaris oryzae with a total inhibition of the mycelial growth. In inoculated rice grains at lower doses (100 and 200 μg/mL) significantly reduced the fungal infection, so O. compactum essential oil could be used as ecofriendly preservative for field and stored Valencia rice.

Chemical composition and bioactivity of different oregano (Origanum vulgare) extracts and essential oil.

PubMed

Teixeira, Bárbara; Marques, António; Ramos, Cristina; Serrano, Carmo; Matos, Olívia; Neng, Nuno R; Nogueira, José M F; Saraiva, Jorge Alexandre; Nunes, Maria Leonor

2013-08-30

There is a growing interest in industry to replace synthetic chemicals by natural products with bioactive properties. Aromatic plants are excellent sources of bioactive compounds that can be extracted using several processes. As far as oregano is concerned, studies are lacking addressing the effect of extraction processes in bioactivity of extracts. This study aimed to characterise the in vitro antioxidant and antibacterial properties of oregano (Origanum vulgare) essential oil and extracts (in hot and cold water, and ethanol), and the chemical composition of its essential oil. The major components of oregano essential oil were carvacrol, β-fenchyl alcohol, thymol, and γ-terpinene. Hot water extract had the strongest antioxidant properties and the highest phenolic content. All extracts were ineffective in inhibiting the growth of the seven tested bacteria. In contrast, the essential oil inhibited the growth of all bacteria, causing greater reductions on both Listeria strains (L. monocytogenes and L. innocua). O. vulgare extracts and essential oil from Portuguese origin are strong candidates to replace synthetic chemicals used by the industry. © 2013 Society of Chemical Industry.

Cyclic and Linear Monoterpenes in Phospholipid Membranes: Phase Behavior, Bilayer Structure, and Molecular Dynamics.

PubMed

Pham, Quoc Dat; Topgaard, Daniel; Sparr, Emma

2015-10-13

Monoterpenes are abundant in essential oils extracted from plants. These relatively small and hydrophobic molecules have shown important biological functions, including antimicrobial activity and membrane penetration enhancement. The interaction between the monoterpenes and lipid bilayers is considered important to the understanding of the biological functions of monoterpenes. In this study, we investigated the effect of cyclic and linear monoterpenes on the structure and dynamics of lipids in model membranes. We have studied the ternary system 1,2-dimyristoyl-sn-glycero-3-phosphocholine-monoterpene-water as a model with a focus on dehydrated conditions. By combining complementary techniques, including differential scanning calorimetry, solid-state nuclear magnetic resonance, and small- and wide-angle X-ray scattering, bilayer structure, phase transitions, and lipid molecular dynamics were investigated at different water contents. Monoterpenes cause pronounced melting point depression and phase segregation in lipid bilayers, and the extent of these effects depends on the hydration conditions. The addition of a small amount of thymol to the fluid bilayer (volume fraction of 0.03 in the bilayer) leads to an increased order in the acyl chain close to the bilayer interface. The findings are discussed in relation to biological systems and lipid formulations.

The anti-dermatophyte activity of Zataria multiflora essential oils.

PubMed

Mahboubi, M; HeidaryTabar, R; Mahdizadeh, E

2017-06-01

Dermtophytes are a group of pathogenic fungi and the major cause of dermatophytosis in humans and animals. Fighting dermatophytes by natural essential oils is one important issue in new researches. In this investigation, we evaluated the anti-dermatophyte activities of three samples of Z. multiflora essential oils against dermatophytes along with analysis of chemical compositions of the essential oils and their anti-elastase activities on elastase production in dermatophytes. Carvacrol (1.5-34.4%), thymol (25.8-41.2%), carvacrol methyl ether (1.9-28.3%) and p-cymene (2.3-8.3%) were the main components of Z. multiflora essential oils. Z. multiflora essential oils (100ppm) inhibited the mycelium growth of dermatophytes (6±1.7-47.0±1.4%) and had the minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values of 0.03-0.25μl/ml against dermatophytes. Essential oils inhibited elastase produced in dermatophytes and pure porcine elastase. Z. multiflora essential oils can be used as natural anti-dermatophyte agent for fighting dermatophytes in further preclinical and clinical studies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Biomedical properties and potentiality of Lippia microphylla Cham. and its essential oils

PubMed Central

Simões, Evelyne Rolim Braun; Santos, Evelyne Alves; de Abreu, Maria Carolina; Silva, Jurandy do Nascimento; Nunes, Nárcia Mariana Fonseca; da Costa, Marcília Pinheiro; Pessoa, Otília Deusdênia Loiola; Pessoa, Cláudia; Ferreira, Paulo Michel Pinheiro

2015-01-01

Lippia microphylla Cham. (Verbenaceae) is an endemic underexploited Brazilian vegetal. This work reviewed the biological potentialities of Lippia microphylla, emphasizing the properties of essential oils (EOs) and analyzed scientific indicators about genus Lippia and L. microphylla. Databases from 1948 to the present were searched and a software (vantage point 7.1) associated with Derwent Innovation Index was used to identify the indicators of the genus Lippia, and biological activities and compounds in the L. macrophylla species. Ethnopharmacological records report use of L. microphylla leaves to treat gastrointestinal disorders, influenza, bronchitis, cough, nasal congestion, and sinusitis during vaporization, whose aromatic volatile oils are rich in monoterpenes, especially cineole, terpineol, and thymol. Other EOs have larvicidal activity on Aedes aegypti larvae, and antifungal, antibacterial and cytotoxic and antitumor action on human and murine cancer cells. Brazil is the country with more articles about Lippia species, but it deposited only 9 patents since 1993. Most of the publications about L. microphylla are concentrated in food and chemical sciences. This bioprospection helps to choice areas of interest for capital investment and to give support for Brazilian Institutions to establish cooperation and improve technological impact at the point of view of creation and innovation. PMID:26401417

Composition and Antimicrobial Activity of Euphrasia rostkoviana Hayne Essential Oil

PubMed Central

Novy, Pavel; Davidova, Hana; Serrano-Rojero, Cecilia Suqued; Rondevaldova, Johana; Pulkrabek, Josef

2015-01-01

Eyebright, Euphrasia rostkoviana Hayne (Scrophulariaceae), is a medicinal plant traditionally used in Europe for the treatment of various health disorders, especially as eyewash to treat eye ailments such as conjunctivitis and blepharitis that can be associated with bacterial infections. Some Euphrasia species have been previously reported to contain essential oil. However, the composition and bioactivity of E. rostkoviana oil are unknown. Therefore, in this study, we investigated the chemical composition and antimicrobial activity of the eyebright essential oil against some organisms associated with eye infections: Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, and Candida albicans. GC-MS analysis revealed more than 70 constituents, with n-hexadecanoic acid (18.47%) as the main constituent followed by thymol (7.97%), myristic acid (4.71%), linalool (4.65%), and anethole (4.09%). The essential oil showed antimicrobial effect against all organisms tested with the exception of P. aeruginosa. The best activity was observed against all Gram-positive bacteria tested with the minimum inhibitory concentrations of 512 µg/mL. This is the first report on the chemical composition of E. rostkoviana essential oil and its antimicrobial activity. PMID:26000025

Composition and Antimicrobial Activity of Euphrasia rostkoviana Hayne Essential Oil.

PubMed

Novy, Pavel; Davidova, Hana; Serrano-Rojero, Cecilia Suqued; Rondevaldova, Johana; Pulkrabek, Josef; Kokoska, Ladislav

2015-01-01

Eyebright, Euphrasia rostkoviana Hayne (Scrophulariaceae), is a medicinal plant traditionally used in Europe for the treatment of various health disorders, especially as eyewash to treat eye ailments such as conjunctivitis and blepharitis that can be associated with bacterial infections. Some Euphrasia species have been previously reported to contain essential oil. However, the composition and bioactivity of E. rostkoviana oil are unknown. Therefore, in this study, we investigated the chemical composition and antimicrobial activity of the eyebright essential oil against some organisms associated with eye infections: Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, and Candida albicans. GC-MS analysis revealed more than 70 constituents, with n-hexadecanoic acid (18.47%) as the main constituent followed by thymol (7.97%), myristic acid (4.71%), linalool (4.65%), and anethole (4.09%). The essential oil showed antimicrobial effect against all organisms tested with the exception of P. aeruginosa. The best activity was observed against all Gram-positive bacteria tested with the minimum inhibitory concentrations of 512 µg/mL. This is the first report on the chemical composition of E. rostkoviana essential oil and its antimicrobial activity.

Improvement of the overall quality of table grapes stored under modified atmosphere packaging in combination with natural antimicrobial compounds.

PubMed

Guillén, F; Zapata, P J; Martínez-Romero, D; Castillo, S; Serrano, M; Valero, D

2007-04-01

Consumers demand new means of preservation with absence of chemicals. In this work a package was developed (thermosealed baskets) with grapes wrapped with 2 distinct films (M and P) with different permeability (medium and high, respectively) without or with the addition of a mixture of eugenol, thymol, and carvacrol. Table grapes stored on air (control) lost their quality attributes very rapidly, manifested by accelerated weight loss, color changes, softening, and increase in soluble solids concentration and titratable acidity ratio (SSC/TA). The use of modified atmosphere packaging (MAP) alone retarded these changes, the effects being significantly greater when essential oils were added (especially for M film), although atmospheric composition was not affected by incorporating essential oils. In addition, microbial counts (molds and yeasts and mesophilic aerobics) were drastically decreased and accompanied by lower occurrence of berry decay. Although slight odor was detected after opening the packages, absence of the typical flavor of these compounds was found by trained panelists after tasting the berries. Thus, with this safe, simple, and innovative technology, the overall quality (sensory and safety) could be improved and considered as a toll alternative to the use of synthetic fungicides.

Evaluation of the quality of herbal teas by DART/TOF-MS.

PubMed

Prchalová, J; Kovařík, F; Rajchl, A

2017-02-01

The paper focuses on the optimization, settings and validation of direct analysis in real time coupled with time-of-flight detector when used for the evaluation of the quality of selected herbal teas (fennel, chamomile, nettle, linden, peppermint, thyme, lemon balm, marigold, sage, rose hip and St. John's wort). The ionization mode, the optimal ionization temperature and the type of solvent for sample extraction were optimized. The characteristic compounds of the analysed herbal teas (glycosides, flavonoids and phenolic and terpenic substances, such as chamazulene, anethole, menthol, thymol, salviol and hypericin) were detected. The obtained mass spectra were evaluated by multidimensional chemometric methods, such as cluster analysis, linear discriminate analysis and principal component analysis. The chemometric methods showed that the single variety herbal teas were grouped according to their taxonomic affiliation. The developed method is suitable for quick identification of herbs and can be potentially used for assessing the quality and authenticity of herbal teas. Direct analysis in real time/time-of-flight-MS is also suitable for the evaluation of selected substances contained in the mentioned herbs and herbal products. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Spectrophotometric determination of fluoxetine hydrochloride in bulk and in pharmaceutical formulations.

PubMed

Prabhakar, A H; Patel, V B; Giridhar, R

1999-07-01

Two new rapid, sensitive and economical spectrophotometric methods are described for the determination of fluoxetine hydrochloride in bulk and in pharmaceutical formulations. Both methods are based on the formation of a yellow ion-pair complex due to the action of methyl orange (MO) and thymol blue (TM) on fluoxetine in acidic (pH 4.0) and basic (pH 8.0) medium, respectively. Under optimised conditions they show an absorption maxima at 433 nm (MO) and 410 nm (TB), with molar absorptivities of 2.12 x 10(-4) and 4.207 x 10(-3) l mol(-1) cm(-1) and Sandell's Sensitivities of 1.64 x 10(-2) and 0.082 microg cm(-2) per 0.001 absorbance unit for MO and TB, respectively. The colour is stable for 5 min after extraction. In both cases Beer's Law is obeyed at 1-20 microg mol(-1) with MO and 4-24 microg mol(-1) with TB. The proposal method was successfully extended to pharmaceutical preparations capsules. The results obtained by both the agreement and E.P. (3rd edition) were in good agreement and statistical comparison by Student's t-test and variance ratio F-test showed no significant difference in the three methods.

Biomedical properties and potentiality of Lippia microphylla Cham. and its essential oils.

PubMed

Simões, Evelyne Rolim Braun; Santos, Evelyne Alves; de Abreu, Maria Carolina; Silva, Jurandy do Nascimento; Nunes, Nárcia Mariana Fonseca; da Costa, Marcília Pinheiro; Pessoa, Otília Deusdênia Loiola; Pessoa, Cláudia; Ferreira, Paulo Michel Pinheiro

2015-01-01

Lippia microphylla Cham. (Verbenaceae) is an endemic underexploited Brazilian vegetal. This work reviewed the biological potentialities of Lippia microphylla, emphasizing the properties of essential oils (EOs) and analyzed scientific indicators about genus Lippia and L. microphylla. Databases from 1948 to the present were searched and a software (vantage point 7.1) associated with Derwent Innovation Index was used to identify the indicators of the genus Lippia, and biological activities and compounds in the L. macrophylla species. Ethnopharmacological records report use of L. microphylla leaves to treat gastrointestinal disorders, influenza, bronchitis, cough, nasal congestion, and sinusitis during vaporization, whose aromatic volatile oils are rich in monoterpenes, especially cineole, terpineol, and thymol. Other EOs have larvicidal activity on Aedes aegypti larvae, and antifungal, antibacterial and cytotoxic and antitumor action on human and murine cancer cells. Brazil is the country with more articles about Lippia species, but it deposited only 9 patents since 1993. Most of the publications about L. microphylla are concentrated in food and chemical sciences. This bioprospection helps to choice areas of interest for capital investment and to give support for Brazilian Institutions to establish cooperation and improve technological impact at the point of view of creation and innovation.

Phytochemistry and nematicidal activity of the essential oils from 8 Greek Lamiaceae aromatic plants and 13 terpene components.

PubMed

Ntalli, Nikoletta G; Ferrari, Federico; Giannakou, Ioannis; Menkissoglu-Spiroudi, Urania

2010-07-14

Eight essential oils (EOs) as well as 13 single terpenes were studied for their nematicidal activity against Meloidogyne incognita , for three immersion periods (24, 48, and 96 h). The EOs were isolated from eight Greek Lamiaceae species: Melissa officinalis , Sideritis clandestina , Origanum dictamnus , Ocimum basilicum , Mentha pulegium , Origanum vulgare , Vitex agnus castus , and Salvia officinalis . The EOs nematicidal activity was correlated to their chemical composition as well as to the pure terpenes' activity tested individually. Clear dose and time response relationships were established. The EOs of O. vulgare, O. dictamnus, M. pulegium, and M. officinalis exhibited high nematicidal activity against M. incognita, and the EC(50) values (96 h) were calculated at 1.55, 1.72, 3.15, and 6.15 muL/mL, respectively. The activity of the nematicidal terpenes was found to decrease in the order l-carvone, pulegone, trans-anethole, geraniol, eugenol, carvacrol, thymol, terpinen-4-ol, and the respective EC(50) values (24 h) were calculated in the range of 115-392 mug/mL. Terpenes tested individually were more active than as components in EO, implementing antagonistic action.

Vapourisers: Physical Principles and Classification

PubMed Central

Dhulkhed, Vithal; Shetti, Akshaya; Naik, Shraddha; Dhulkhed, Pavan

2013-01-01

Vapourisers have evolved from rudimentary inhalers to the microprocessor controlled, temperature compensated and flow sensing devices, which are universal today. The improvements in the design was influenced by the development of potent inhalational anaesthetics, unique properties of some agents, a deeper understanding of their mechanism of action, inherent flaws in the older vapourisers, mechanical problems due to thymol deposition, factors influencing their output such as temperature and pressure variations. It is important to review the principles governing the design of the vapouriser to gain insight into their working. It is fascinating to know how some of the older vapourisers, popularly used in the past, functioned. The descendant of Oxford Miniature Vapourizer, the Triservice vapouriser is still a part of the military anaesthesia draw over equipment meant for field use whereas the Copper Kettle the first precision device is the fore-runner of the Tec 6 and Aladdin cassette vapouriser. Anaesthesia trainees if exposed to draw over techniques get a deeper understanding of equipment and improved skills for disaster situations. In the recent advanced versions of the vapouriser a central processing unit in the anaesthetic machine controls the operation by continuously monitoring and adjusting fresh gas flow through the vapouriser to maintain desired concentration of the vapour. PMID:24249878

Evaluation of three headspace sorptive extraction coatings for the determination of volatile terpenes in honey using gas chromatography-mass spectrometry.

PubMed

Cacho, J I; Campillo, N; Viñas, P; Hernández-Córdoba, M

2015-06-19

Headspace sorptive extraction (HSSE) was used to preconcentrate seven monoterpenes (eucalyptol, linalool, menthol, geraniol, carvacrol, thymol and eugenol) for separation by gas chromatography and mass spectrometry (GC-MS). Three commercially available coatings for the stir bars, namely Polydimethylsiloxane (PDMS), polyacrilate (PA) and Ethylene glycol-silicone (EG-Silicone), were tested, and the influential parameters both in the adsorption and the thermal desorption steps were optimized. PDMS provided the best sensitivity for linalool, geraniol, menthol and eucalyptol, whereas EG-Silicone was best for extracting the phenolic monoterpenes studied. Considering the average obtained slopes from all compounds, PDMS pointed as the best option, and the analytical characteristics for the HSSE-TD-GC-MS method using this coating were obtained. Quantification of the samples was carried out by matrix-matched calibration using a synthetic honey. Detection limits ranged between 0.007 and 0.032 ng g(-1), depending on the compound. Twelve honey samples of different floral origins were analyzed using the HSSE-GC-MS method, the analytes being detected at concentrations up to 64 ng g(-1). Copyright © 2015 Elsevier B.V. All rights reserved.

Antimicrobial Activity and Chemical Composition of Three Essential Oils Extracted from Mediterranean Aromatic Plants.

PubMed

Elshafie, Hazem S; Sakr, Shimaa; Mang, Stefania M; Belviso, Sandra; De Feo, Vincenzo; Camele, Ippolito

2016-11-01

There is a growing interest in essential oils (EOs) as possible alternatives for traditional chemical pesticides. This study was carried out to characterize the chemical composition of the three EOs extracted from Verbena officinalis, Majorana hortensis, and Salvia officinalis using gas chromatography (GC) and GC-mass spectrometry (GC-MS) and to evaluate in vitro their efficacy against some phyto or human pathogens. The antifungal activity was investigated against Colletotrichum acutatum and Botrytis cinerea in comparison with Azoxystrobin as a large spectrum fungicide. Antibacterial activity was evaluated against Bacillus megaterium, Bacillus mojavensis, and Clavibacter michiganensis (G+ve) and Escherichia coli, Xanthomonas campestris, Pseudomonas savastanoi, and P. syringae pv. phaseolicola (G-ve) compared to a synthetic antibiotic tetracycline. Minimum inhibitory concentration was evaluated against the above tested fungi using 96-well microplate method. Results showed that the chemical structure of the three studied EOs was mainly composed of monoterpene compounds and all oils belong to the chemotype carvacrol/thymol. Results of GC analysis identified 64 compounds, which were identified based on their mass to charge ratio. Furthermore, the different concentrations of studied EOs inhibited the growth of tested microorganism in a dose-dependent manner.

Evaluation of the Cytotoxicity of Satureja spicigera and Its Main Compounds

PubMed Central

Gohari, Ahmad Reza; Ostad, Seyed Nasser; Moradi-Afrapoli, Fahimeh; Malmir, Maryam; Tavajohi, Shohreh; Akbari, Hassan; Saeidnia, Soodabeh

2012-01-01

Satureja spicigera (Lamiaceae) grows wildly in Northwest of Iran. In this study, bioassay-guided isolation and identification of the main compounds has been reported using various chromatographic methods and comparison of their spectral data with those reported in the literature. Brine shrimp lethality and four cancerous cell lines HT29/219, Caco2, NIH-3T3, and T47D were used for cytotoxicity evaluations. From the aerial parts of S. spicigera, nine known compounds including two flavanones, 5,7,3′,5′-tetrahydroxy flavanone (8) and 5,4′-dihydroxy-3′-methoxyflavanone-7-(6′′-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (9), one dihydrochalcone, nubigenol (7), together with thymoquinone (1), thymol (2), carvacrol (3), β-sitosterol (4), ursolic acid (5) and oleanolic acid (6) were identified. Among the isolated chalcone and flavanones, compound 8 was effective against Artemia salina larva (LC50= 2 μg/mL) and only the compound 9 demonstrated IC50 value of 98.7 μg/mL on the T47D (human, breast, ductal carcinoma). Other compounds did not show significant inhibition of the cell growth. PMID:22623883

Antimicrobial Activity and Chemical Composition of Essential Oils from Verbenaceae Species Growing in South America.

PubMed

Pérez Zamora, Cristina M; Torres, Carola A; Nuñez, María B

2018-03-01

The Verbenaceae family includes 2600 species grouped into 100 genera with a pantropical distribution. Many of them are important elements of the floras of warm-temperature and tropical regions of America. This family is known in folk medicine, and its species are used as digestive, carminative, antipyretic, antitussive, antiseptic, and healing agents. This review aims to collect information about the essential oils from the most reported species of the Verbenaceae family growing in South America, focusing on their chemical composition, antimicrobial activity, and synergism with commercial antimicrobials. The information gathered comprises the last twenty years of research within the South American region and is summarized taking into consideration the most representative species in terms of their essential oils. These species belong to Aloysia , Lantana , Lippia , Phyla , and Stachytarpheta genera, and the main essential oils they contain are monoterpenes and sesquiterpenes, such as β-caryophyllene, thymol, citral, 1,8-cineole, carvone, and limonene. These compounds have been found to possess antimicrobial activities. The synergism of these essential oils with antibiotics is being studied by several research groups. It constitutes a resource of interest for the potential use of combinations of essential oils and antibiotics in infection treatments.

Enzyme/indicator optrodes for detection of heavy metal ions and pesticides

NASA Astrophysics Data System (ADS)

Nabok, Alexei V.; Ray, Asim K.; Starodub, Nickolaj F.; Dowker, Kenneth P.

2000-12-01

Composite films containing enzyme and indicator molecules were produced by means of polyelectrolyte self-assembly. These membranes provide two functions: (i) molecular recognition of the substratum by respective enzyme, and (ii) optrode transducing, when the products o the substratum decomposition affect optical spectra of indicator molecules. Apart from direct registration of enzyme reactions, inhibition reactions can also be monitored with this method. Particularly, heavy metal salts and phosphor organic pesticides acting as inhibitors for Urease and Cholinesterase, respectively, were registered. Composite PESA films were deposited onto glass slides and consisted of several layers of poly(alylamine) hydrochloride (PAA) alternated with indicator molecules, either Cyclo-tetra- chromotropylene or Thymol Blue, both containing SO3- Na+ groups. Then a few layers of PAA/enzyme were deposited on top. A typical structure of the samples was (PAA/Indicator)n/(PAA/Enzyme)m/PAA with n equals 1-5. The obtained films were characterized with UV-visible absorption spectroscopy. The effect of the substrate decomposition on the UV-vis spectra of respective indicator molecules was studied. The inhibition of enzymes Urease and Cholinesterase by heavy metal ions and phosphor organic pesticide, respectively was found. The results obtained show the prospects towards development of optical enzyme sensor arrays.

Changes in growth, hormones levels and essential oil content of Ammi visnaga L. plants treated with some bioregulators

PubMed Central

Talaat, Iman M.; Khattab, Hemmat I.; Ahmed, Aisha M.

2013-01-01

The effects of foliar application of different concentrations of amino acids (tyrosine and phenylalanine) and phenolic acids (trans-cinnamic acid, benzoic acid and salicylic acid) on growth, pigment content, hormones levels and essential oil content of Ammi visnaga L were carried out during two successive seasons. It is clear that foliar application of either amino acids or phenolics significantly promoted the growth parameters in terms of shoot height, fresh and dry biomass, number of branches and number of umbels per plant. The increment of growth parameter was associated with elevated levels of growth promoters (IAA, GA3, total cytokinins) and low level of ABA. The greatest increase in the previously mentioned parameters was measured in plants exposed to different concentrations of phenols particularly in benzoic acid-treated plants. Such effect was concentration dependent. All treatments led to significant increments in yield seeds and oil content. Moreover, gas liquid chromatographic analysis revealed that the main identified components of essential oil were 2,2-dimethyl butanoic acid, isobutyl isobutyrate, α-isophorone, thymol, fenchyl acetate and linalool. Phenolics and amino acid treatments resulted in qualitative differences in these components of essential oil. PMID:25183946

Radiosensitization: enhancing the radiation inactivation of foodborne bacteria

NASA Astrophysics Data System (ADS)

Borsa, J.; Lacroix, M.; Ouattara, B.; Chiasson, F.

2004-09-01

Irradiation of meat products to kill pathogens can be limited by radiation-induced detriment of sensory quality. Since such detriment is directly related to dose, one approach to reduce it is by devising means to lower the dose of radiation required for processing. Increasing the radiation sensitivity of the target microorganisms would lower the dose required for a given level of microbial kill. In this work, the radiation sensitivities of inoculated Escherichia coli and Salmonella typhi in ground beef were examined under a variety of conditions. Results showed that specific manipulations of treatment conditions significantly increased the radiation sensitivity of the test organisms, ranging from a few percent to several-fold reduction in D10. In particular, radiation sensitization could be effected by certain additives, including carvacrol, thymol and trans-cinnamaldehyde, and also by certain compositions of modified atmosphere in the package headspace. A combination of additives and modified atmosphere effected a greater radiosensitization effect than could be achieved by either factor applied alone. Radiosensitization could be demonstrated with irradiation of either fresh or frozen ground meat. The radiosensitization phenomenon may be of practical utility in enhancing the technical effectiveness and feasibility of irradiation of a variety of meat and other food products.

Phytochemical Prospection and Modulation of Antibiotic Activity In Vitro by Lippia origanoides H.B.K. in Methicillin Resistant Staphylococcus aureus

PubMed Central

Medeiros Barreto, Humberto; Cerqueira Fontinele, Filipe; Pereira de Oliveira, Aldeídia; Arcanjo, Daniel Dias Rufino; Cavalcanti dos Santos, Bernadete Helena; de Abreu, Aislan Pereira Lira; Douglas Melo Coutinho, Henrique; Alves Carvalho da Silva, Romezio; Oliveira de Sousa, Taciana; Freire de Medeiros, Maria das Graças; Lopes Citó, Antonia Maria das Graças; Dantas Lopes, José Arimateia

2014-01-01

The Lippia origanoides H.B.K. ethanol extract (LOEE) and hexane (LOHEX), dichloromethane (LODCM), and ethyl acetate (LOEA) fractions were tested for their antimicrobial activity alone or in combination with antibiotics against a methicillin resistant Staphylococcus aureus (MRSA) strain. The natural products did not show antimicrobial activity against multidrug resistant strain at the clinically significant concentrations tested. However, a modulatory effect in the antibacterial activity of the neomycin and amikacin was verified when LOEE, LOHEX and LODCM were added to the growth medium at subinhibitory concentrations. A similar modulation was found when the natural products were changed for chlorpromazine, an inhibitor of bacterial efflux pumps, suggesting the involvement of resistance mediated by efflux system in the MRSA tested. The fractions LOHEX and LODCM showed a modulatory activity bigger than their majority compounds (carvacrol, thymol, and naringenin), indicating that this activity is not due to their majority compounds only, but it is probably due to a synergism between their chemical components. These results indicate that L. origanoides H.B.K. can be a source of phytochemicals able to modify the phenotype of resistance to aminoglycosides in MRSA. PMID:24683545

Development of an underwater in-situ spectrophotometric sensor for seawater pH

NASA Astrophysics Data System (ADS)

Waterbury, Robert D.; Byrne, Robert H.; Kelly, John; Leader, Bram; McElligott, Sean; Russell, Randy

1996-12-01

A pH sensor based upon spectrophotometric techniques has been developed for in-situ analysis of surface seawater. This sensor utilizes a spectrophotometric pH indicator (Thymol Blue) which has been calibrated for use in seawater as a function of temperature and salinity. Shipboard spectrophotometric pH analyses routinely demonstrate a precision on the order of plus or minus 0.0004 pH units. In- situ analysis of seawater pH has demonstrated a precision on the order of plus or minus 0.001 and an accuracy, using shipboard measurements as a standard, on the order of plus or minus 0.01. The sensor is a self-contained system which pumps seawater, meters in indicator, spectrophotometrically determines indicator absorbance and stores data with a 1 Hz acquisition frequency. The sensor employs two absorbance cells, each with three wavelength channels, to obtain the spectrophotometric absorbance. The sensor system, rated for depths up to 500 m, provides pH, conductivity, temperature and can be operated via computer or in a standalone mode with internal data storage. The sensor utilizes less than 12 watts of power and is packaged in a 29' long by 4.5' diameter aluminum housing.

Evaluation of natural antimicrobials on typical meat spoilage bacteria in vitro and in vacuum-packed pork meat.

PubMed

Schirmer, Bjørn Christian; Langsrud, Solveig

2010-03-01

The aim of this study was to investigate the inhibitory effect of natural antimicrobials on the growth of typical spoilage bacteria from marinated pork. Minimum inhibitory concentrations (MIC) of thymol, cinnamaldehyde, allyl isothiocyanate, citric acid, ascorbic acid, a rosemary extract, and a grapefruit seed extract against Lactobacillus algidus, Leuconostoc mesenteroides, Leuconostoc carnosum, Carnobacterium maltaromaticum, Carnobacterium divergens, Brochothrix thermosphacta, and Serratia proteamaculans were determined in a microplate assay. Combinations of antimicrobials were tested and several combinations showed synergistic effects in inhibiting bacterial growth. Single and combined antimicrobials were added to vacuum-packed pork meat to evaluate preserving effects. Antimicrobial concentrations of up to 10 times the MIC values showed no effect on total bacterial growth in vacuum packed pork meaning that although most antimicrobials inhibited the growth of spoilage bacteria in vitro, results from the microplate assay could not be transferred to the meat system. Most natural antimicrobials possess strong odor and flavor that limit their use as a food preservative. In conclusion, this study showed that the use of natural antimicrobials in meat products is limited and that bacterial quality and shelf life was not enhanced under the chosen conditions.

Chemoprevention by thyme oils of Aspergillus parasiticus growth and aflatoxin production.

PubMed

Rasooli, Iraj; Owlia, Parviz

2005-12-01

The essential oils from Thymus eriocalyx and Thymus X-porlock obtained by hydrodistillation were analyzed by GC/MS. The major components of T. eriocalyx and T. X-porlock oils were thymol (63.8, 31.7%), beta-phellandrene (13.30, 38.7%), cis-sabinene hydroxide (8.1, 9.6%), 1,8-cineole (2, 1.7%), and beta-pinene (1.31, 2%), respectively. Antifungal activities of the oils were studied with special reference to the inhibition of Aspergillus parasiticus growth and aflatoxin production. Minimal inhibitory (MIC) and minimal fungicidal (MFC) concentrations of the oils were determined. Static effects of the above oils against A. parasiticus were at 250 ppm and lethal effects of T. eriocalyx and T. X-porlock were 500 and 1000 ppm of the oils, respectively. Aflatoxin production was inhibited at 250 ppm of both oils with that of T. eriocalyx being stronger inhibitor. Transmission electron microscopy (TEM) of A. parasiticus exposed to MIC level (250 ppm) of the oils showed irreversible damage to cell wall, cell membrane, and cellular organelles. It is concluded that the essential oils could be safely used as preservative materials on some kinds of foods at low concentrations to protect them from fungal infections.

Biopreservation of hamburgers by essential oil of Zataria multiflora.

PubMed

Samadi, N; Sharifan, A; Emam-Djomeh, Z; Sormaghi, M H Salehi

2012-01-01

Hamburgers with high nutrient supply and a loosely-packed structure present favourable conditions for microbial growth. In this study, the chemical composition and antimicrobial activity of the essential oil of Zataria multiflora and its potential application as a natural preservative in reducing the indigenous microbial population of hamburgers were investigated. Carvacrol, thymol and linalool were found to be the most abundant constituents of the essential oil using GC-MS analysis. The essential oil exhibited strong antibacterial activity against Gram-positive and Gram-negative bacteria. Addition of Z. multiflora essential oil in concentrations higher than MIC values influenced the microbial population of hamburgers stored at 25°C, 4°C and -12°C. The significant results of this study are our observations that the use of Z. multiflora essential oil at 0.05% v/w increases the time needed for the natural microflora of hamburgers to reach concentrations able to produce a perceivable spoilage at refrigerator and room temperatures without any inverse effect on their sensory attributes. Freezing of essential oil-treated hamburgers may also reduce the risk of diseases associated with consumption of under-cooked hamburgers through significant microbial reduction by more than 3 log.

Therapeutic Potential of Zataria multiflora Boiss in Treatment of Irritable Bowel Syndrome (IBS).

PubMed

Mahboubi, Mohaddese

2018-01-15

Irritable Bowel syndrome (IBS), the most common chronic functional gastrointestinal disorder, is categorized as IBS-C and IBS-D, which are equivalent to Ghoolenj Rihi and Maghs Rihi in Iranian traditional medicine. One of the main applications of Zataria multiflora Boiss in traditional medicine is its efficacy in the gastrointestinal tract with symptoms such as IBS. The aim of this study was to evaluate the efficacy of Zataria multiflora essential oil in management of IBS. We used all the accessible references (electronic and published books, theses, and reports) to write this article. The results of our investigation show that the majority of gas chromatography-mass spectrometry (GC-MS) analyses exhibited carvacrol and thymol as the main components of Zataria multiflora essential oil, and 60 drops oral daily dose of Z. multiflora essential oil (2%) can relieve the symptoms of IBS without any adverse effects. The pharmacological studies confirmed the analgesic, anti-inflammatory, antispasm and antiulcer effects of Z. multiflora essential oils and main components. According to the results of studies, oral Z. multiflora essential oil (2%) is a good candidate for management of IBS, but more studies are required to better understand its efficacies.

Essential oil diversity of European Origanum vulgare L. (Lamiaceae).

PubMed

Lukas, Brigitte; Schmiderer, Corinna; Novak, Johannes

2015-11-01

This investigation focused on the qualitative and quantitative composition of essential oil compounds of European Origanum vulgare. Extracts of 502 individual O. vulgare plants from 17 countries and 51 populations were analyzed via GC. Extracts of 49 plants of 5 populations of Israeli Origanum syriacum and 30 plants from 3 populations of Turkish Origanum onites were included to exemplify essential oil characteristics of 'high-quality' oregano. The content of essential oil compounds of European O. vulgare ranged between 0.03% and 4.6%. The monoterpenes were primarily made up of sabinene, myrcene, p-cymene, 1,8-cineole, β-ocimene, γ-terpinene, sabinene hydrate, linalool, α-terpineol, carvacrol methyl ether, linalyl acetate, thymol and carvacrol. Among the sesquiterpenes β-caryophyllene, germacrene D, germacrene D-4-ol, spathulenol, caryophyllene oxide and oplopanone were often present in higher amounts. According to the proportions of cymyl-compounds, sabinyl-compounds and the acyclic linalool/linalyl acetate three different main monoterpene chemotypes were defined. The cymyl- and the acyclic pathway were usually active in plants from the Mediterranean climate whereas an active sabinyl-pathway was a characteristic of plants from the Continental climate. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dittany of Crete: a botanical and ethnopharmacological review.

PubMed

Liolios, Christos C; Graikou, Konstantia; Skaltsa, Eleni; Chinou, Ioanna

2010-09-15

Origanum dictamnus (Lamiaceae family), an endemic plant of the Greek island of Crete, is widely used as a traditional medicine since antiquity, all over Europe. The aim of the present review is to present comprehensive information of the plant's botanical taxonomy and morphology, as well as of the chemical constituents, biological and pharmacological research on O. dictamnus, which will be presented and critically evaluated. The paper also highlights particularly interesting aspects and common medicinal uses not previously described in the specific ethnobotanical literature. An increasing number of chemical and pharmacological studies have been reported recently, some of which strongly support its traditional medicinal uses against various illnesses such as sore throat, cough and gastric ulcer. A variety of compounds, including flavonoids, lipids and terpenoids (mainly carvacrol and thymol) have been identified from the plant. Current studies have showed that the extracts, the essential oil, as well as their active principles possess several pharmacological properties, like antimicrobial, antioxidant and anti-ulcer ones. The recent scientific data and the rich historical evidence of its medicinal uses could support further research as well as its use as a safe herbal medicinal product. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Extraction of the essential oil from endemic Origanum bilgeri P.H.Davis with two different methods: comparison of the oil composition and antibacterial activity.

PubMed

Sözmen, Fazli; Uysal, Burcu; Köse, Elif Odabaş; Aktaş, Ozgür; Cinbilgel, Ilker; Oksal, Birsen S

2012-07-01

The antibacterial activity and chemical composition of the essential oils (EOs) isolated from Origanum bilgeri P.H.Davis by two different extraction methods, i.e., hydrodistillation (HD) and solvent-free microwave extraction (SFME), were examined. This endemic Origanum species had shown very good antibacterial activity. The composition of the O. bilgeri EOs obtained by SFME and HD was investigated by GC/MS analysis. The main components of the oils obtained by both methods were carvacrol (90.20-84.30%), p-cymene (3.40-5.85%), γ-terpinene (0.47-1.20%), and thymol (0.69-1.08%). The EO isolation by SFME offered many important advantages, including a higher extraction yield, a shorter extraction time, and a higher content of the active component carvacrol. The carvacrol-rich oils obtained by both HD and SFME showed a good antibacterial activity. The largest inhibition zones were observed for the O. bilgeri EO obtained by SFME. Our study suggests that O. bilgeri EO has the potential to be used as preventative against bacterial contamination in many foods, instead of the common synthetic antimicrobial products. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.

Anesthetic Agents of Plant Origin: A Review of Phytochemicals with Anesthetic Activity.

PubMed

Tsuchiya, Hironori

2017-08-18

The majority of currently used anesthetic agents are derived from or associated with natural products, especially plants, as evidenced by cocaine that was isolated from coca ( Erythroxylum coca , Erythroxylaceae) and became a prototype of modern local anesthetics and by thymol and eugenol contained in thyme ( Thymus vulgaris , Lamiaceae) and clove ( Syzygium aromaticum , Myrtaceae), respectively, both of which are structurally and mechanistically similar to intravenous phenolic anesthetics. This paper reviews different classes of phytochemicals with the anesthetic activity and their characteristic molecular structures that could be lead compounds for anesthetics and anesthesia-related drugs. Phytochemicals in research papers published between 1996 and 2016 were retrieved from the point of view of well-known modes of anesthetic action, that is, the mechanistic interactions with Na⁺ channels, γ-aminobutyric acid type A receptors, N -methyl-d-aspartate receptors and lipid membranes. The searched phytochemicals include terpenoids, alkaloids and flavonoids because they have been frequently reported to possess local anesthetic, general anesthetic, antinociceptive, analgesic or sedative property. Clinical applicability of phytochemicals to local and general anesthesia is discussed by referring to animal in vivo experiments and human pre-clinical trials. This review will give structural suggestions for novel anesthetic agents of plant origin.

Protection of Wood from Microorganisms by Laccase-Catalyzed Iodination

PubMed Central

Engel, J.; Thöny-Meyer, L.; Schwarze, F. W. M. R.; Ihssen, J.

2012-01-01

In the present work, Norway spruce wood (Picea abies L.) was reacted with a commercial Trametes versicolor laccase in the presence of potassium iodide salt or the phenolic compounds thymol and isoeugenol to impart an antimicrobial property to the wood surface. In order to assess the efficacy of the wood treatment, a leaching of the iodinated and polymerized wood and two biotests including bacteria, a yeast, blue stain fungi, and wood decay fungi were performed. After laccase-catalyzed oxidation of the phenols, the antimicrobial effect was significantly reduced. In contrast, the enzymatic oxidation of iodide (I−) to iodine (I2) in the presence of wood led to an enhanced resistance of the wood surface against all microorganisms, even after exposure to leaching. The efficiency of the enzymatic wood iodination was comparable to that of a chemical wood preservative, VP 7/260a. The modification of the lignocellulose by the laccase-catalyzed iodination was assessed by the Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) technique. The intensities of the selected lignin-associated bands and carbohydrate reference bands were analyzed, and the results indicated a structural change in the lignin matrix. The results suggest that the laccase-catalyzed iodination of the wood surface presents an efficient and ecofriendly method for wood protection. PMID:22865075

Essential Oil Yield Pattern and Antibacterial and Insecticidal Activities of Trachyspermum ammi and Myristica fragrans.

PubMed

Soni, Rajgovind; Sharma, Gaurav; Jasuja, Nakuleshwar Dut

2016-01-01

Two Indian spices, Trachyspermum ammi and Myristica fragrans, were studied for their essential oil (EO) yielding pattern, insecticidal activity, antibacterial activity, and composition. The essential oils (EOs) of T. ammi (1.94 ± 30 mL/100 gm) and M. fragrans (5.93 ± 90 mL/100 gm) were extracted using hydrodistillation method. In Gas Chromatography analysis, the beta-pinene, alpha-pinene, alpha-p-menth-1-en-4-ol, Limonene, and elemicin were found as major constituents of T. ammi essential oil whereas M. fragrans essential oil mostly contains Gamma-Terpinolene, p-Cymene, Thymol, and beta-pinene. The insecticidal activities of EO were demonstrated using LC50 values against Plodia interpunctella and EO of T. ammi was found comparatively more effective than EO of M. fragrans. Further, individual EO and combination of essential oil were examined for antibacterial activity against three Gram (-) bacterial strains (E. coli-MTCC 443, P. vulgaris-MTCC 1771, and K. pneumoniae-MTCC number 7028) and three Gram (+) bacterial strains (S. aureus-MTCC 3381, B. subtilis-MTCC 10619, and B. megaterium-MTCC 2412) by well agar diffusion method. The essential oil in combination (CEO) exhibited higher antibacterial activity as compared with individual essential oils.

Antimicrobial activities of commercial essential oils and their components against food-borne pathogens and food spoilage bacteria

PubMed Central

Mith, Hasika; Duré, Rémi; Delcenserie, Véronique; Zhiri, Abdesselam; Daube, Georges; Clinquart, Antoine

2014-01-01

This study was undertaken to determine the in vitro antimicrobial activities of 15 commercial essential oils and their main components in order to pre-select candidates for potential application in highly perishable food preservation. The antibacterial effects against food-borne pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and enterohemorrhagic Escherichia coli O157:H7) and food spoilage bacteria (Brochothrix thermosphacta and Pseudomonas fluorescens) were tested using paper disk diffusion method, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Most of the tested essential oils exhibited antimicrobial activity against all tested bacteria, except galangal oil. The essential oils of cinnamon, oregano, and thyme showed strong antimicrobial activities with MIC ≥ 0.125 μL/mL and MBC ≥ 0.25 μL/mL. Among tested bacteria, P. fluorescens was the most resistant to selected essential oils with MICs and MBCs of 1 μL/mL. The results suggest that the activity of the essential oils of cinnamon, oregano, thyme, and clove can be attributed to the existence mostly of cinnamaldehyde, carvacrol, thymol, and eugenol, which appear to possess similar activities against all the tested bacteria. These materials could be served as an important natural alternative to prevent bacterial growth in food products. PMID:25473498

Bioactivity of essential oils in phytopathogenic and post-harvest fungi control.

PubMed

Santamarina, M P; Ibáñez, M D; Marqués, M; Roselló, J; Giménez, S; Blázquez, M A

2017-11-01

Commercial thyme and lavender essential oils were analysed by GC/MS. Sixty-six compounds accounting for 98.6-99.6% of total essential oil were identified. Thymol (52.14 ± 0.21%), followed by p-cymene (32.24 ± 0.16%), carvacrol (3.71 ± 0.01%) and γ-terpinene (3.34 ± 0.02%), were the main compounds in thyme essential oil, while large amounts of oxygenated monoterpenes linalool acetate (37.07 ± 0.24%) and linalool (30.16 ± 0.06%) were found in lavender one. In vitro antifungal activity of the essential oils was evaluated at 200 and 300 μg/mL against 10 phytopathogenic and post-harvest fungi, which significantly affect agriculture. Micelial growth inhibition was calculated for each tested fungus and dose. Thyme essential oil showed satisfactory results with 90-100% growth inhibition in almost all the assayed fungi at 300 μg/mL, while lavender essential oil showed no noteworthy inhibition data at either dose, and its growth was even enhanced. Thyme essential oil represents a natural alternative to control harvest and post-harvest fungi, and to extend the shelf-life of agriculture products.

A review on the inhibitory potential of Nigella sativa against pathogenic and toxigenic fungi.

PubMed

Shokri, Hojjatollah

2016-01-01

Nigella sativa (N. sativa) grows in various parts of the world, particularly in Iran. It has been traditionally used as a folk remedy to treat a number of diseases. The seeds of this plant contain moisture, proteins, carbohydrates, crude fiber, alkaloids, saponins, ash, fixed oils and essential oil. The major components of the essential oil are thymoquinone, p-cymene, trans-anethole, 2-methyl-5(1-methyl ethyl)-Bicyclo[3.1.0]hex-2-en and γ-terpinene. So far, several pharmacological effects such as anti-oxidant, anti-inflammatory, anti-cancer and anti-microbial have been reported for N. sativa or its active compounds. Thymoquinone, thymohydroquinone and thymol are the most active constituents which have different beneficial properties. The oil, extracts and some of N. sativa active components possessed moderate in vitro and in vivo inhibitory activity against pathogenic yeasts, dermatophytes, non-dermatophytic filamentous fungi and aflatoxin-producing fungi. The main morphological changes of pathogenic and toxigenic fungi treated with N. sativa oil were observed in the cell wall, plasma membrane and membranous organelles, particularly in the nuclei and mitochondria. Although this review represents first step in the search for a new anti-fungal drug, the full potential of N. sativa as a fungitoxic agent has not been exploited and necessitates further investigations.

Oregano Essential Oil as an Antimicrobial and Antioxidant Additive in Food Products.

PubMed

Rodriguez-Garcia, I; Silva-Espinoza, B A; Ortega-Ramirez, L A; Leyva, J M; Siddiqui, M W; Cruz-Valenzuela, M R; Gonzalez-Aguilar, G A; Ayala-Zavala, J F

2016-07-26

Food consumers and industries urged the need of natural alternatives to assure food safety and quality. As a response, the use of natural compounds from herbs and spices is an alternative to synthetic additives associated with toxic problems. This review discusses the antimicrobial and antioxidant activity of oregano essential oil (OEO) and its potential as a food additive. Oregano is a plant that has been used as a food seasoning since ancient times. The common name of oregano is given to several species: Origanum (family: Lamiaceae) and Lippia (family: Verbenaceae), amongst others. The main compounds identified in the different OEOs are carvacrol and thymol, which are responsible for the characteristic odor, antimicrobial, and antioxidant activity; however, their content may vary according to the species, harvesting season, and geographical sources. These substances as antibacterial agents make the cell membrane permeable due to its impregnation in the hydrophobic domains, this effect is higher against gram positive bacteria. In addition, the OEO has antioxidant properties effective in retarding the process of lipid peroxidation in fatty foods, and scavenging free radicals. In this perspective, the present review analyzes and discusses the state of the art about the actual and potential uses of OEO as an antimicrobial and antioxidant food additives.

Elaboration of antibiofilm surfaces functionalized with antifungal-cyclodextrin inclusion complexes.

PubMed

Gharbi, Aïcha; Humblot, Vincent; Turpin, Frédéric; Pradier, Claire-Marie; Imbert, Christine; Berjeaud, Jean-Marc

2012-07-01

To tackle the loss of activity of surfaces functionalized by coating and covalently bound molecules to materials, an intermediate system implying the noncovalent immobilization of active molecules in the inner cavity of grafted cyclodextrins (CDs) was investigated. The antifungal and antibiofilm activities of the most stable complexes of Anidulafungin (ANF; echinocandin) and thymol (THY; terpen) in various CDs were demonstrated to be almost the same as the free molecules. The selected CD was covalently bond to self-assembled monolayers on gold surfaces. The immobilized antifungal agents reduced the number of culturable Candida albicans ATCC 3153 attached to the surface by 64 ± 8% for ANF and 75 ± 15% for THY. The inhibitory activity was persistent for THY-loaded samples, whereas it was completely lost for ANF-loaded surfaces after one use. However, reloading of the echinocandin restored the activity. Using fluorescent dying and confocal microscopy, it was proposed that the ANF-loaded surfaces inhibited the adherence of the yeasts, whereas the activity of immobilized THY was found fungicidal. This kind of tailored approach for functionalizing surfaces that could allow a progressive release of ANF or THY gave promising results but still needs to be improved to display a full activity. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Antimicrobial, Optical and Mechanical Properties of Chitosan-Starch Films with Natural Extracts.

PubMed

Lozano-Navarro, Jessica I; Díaz-Zavala, Nancy P; Velasco-Santos, Carlos; Martínez-Hernández, Ana L; Tijerina-Ramos, Beatriz I; García-Hernández, Margarita; Rivera-Armenta, José L; Páramo-García, Ulises; Reyes-de la Torre, Adriana I

2017-05-05

Natural extracts possess several kinds of antioxidants (anthocyanins, betalains, thymol, carvacrol, and resveratrol) that have also demonstrated antimicrobial properties. In order to study these properties, extracts from cranberry, blueberry, beetroot, pomegranate, oregano, pitaya, and resveratrol (from grapes) were obtained. Growth inhibition tests of mesophilic aerobes, coliforms, and fungi were conducted in films prepared from the extracts in accordance with Mexican Official Norms (NOM). Optical properties such as transparency and opacity, mechanical properties, and pH were also analyzed in these materials. The films with beetroot, cranberry, and blueberry extracts demonstrated the best antimicrobial activity against various bacteria and fungi in comparison with unmodified chitosan-starch film. This study shows that the addition of antioxidants improved the antimicrobial performance of these films. It was also found that antimicrobial properties are inherent to the films. These polymers combined with the extracts effectively inhibit or reduce microorganism growth from human and environmental contact; therefore, previous sterilization could be unnecessary in comparison with traditional plastics. The presence of extracts decreased transmittance percentages at 280 and 400 nm, as well as the transparency values, while increasing their opacity values, providing better UV-VIS light barrier properties. Despite diminished glass transition temperatures ( T g), the values obtained are still adequate for food packaging applications.

Antimicrobial, Optical and Mechanical Properties of Chitosan–Starch Films with Natural Extracts

PubMed Central

Lozano-Navarro, Jessica I.; Díaz-Zavala, Nancy P.; Velasco-Santos, Carlos; Martínez-Hernández, Ana L.; Tijerina-Ramos, Beatriz I.; García-Hernández, Margarita; Rivera-Armenta, José L.; Páramo-García, Ulises; Reyes-de la Torre, Adriana I.

2017-01-01

Natural extracts possess several kinds of antioxidants (anthocyanins, betalains, thymol, carvacrol, and resveratrol) that have also demonstrated antimicrobial properties. In order to study these properties, extracts from cranberry, blueberry, beetroot, pomegranate, oregano, pitaya, and resveratrol (from grapes) were obtained. Growth inhibition tests of mesophilic aerobes, coliforms, and fungi were conducted in films prepared from the extracts in accordance with Mexican Official Norms (NOM). Optical properties such as transparency and opacity, mechanical properties, and pH were also analyzed in these materials. The films with beetroot, cranberry, and blueberry extracts demonstrated the best antimicrobial activity against various bacteria and fungi in comparison with unmodified chitosan–starch film. This study shows that the addition of antioxidants improved the antimicrobial performance of these films. It was also found that antimicrobial properties are inherent to the films. These polymers combined with the extracts effectively inhibit or reduce microorganism growth from human and environmental contact; therefore, previous sterilization could be unnecessary in comparison with traditional plastics. The presence of extracts decreased transmittance percentages at 280 and 400 nm, as well as the transparency values, while increasing their opacity values, providing better UV–VIS light barrier properties. Despite diminished glass transition temperatures (Tg), the values obtained are still adequate for food packaging applications. PMID:28475151

Antimicrobial activity of five essential oils against origin strains of the Enterobacteriaceae family.

PubMed

Peñalver, Pedro; Huerta, Belén; Borge, Carmen; Astorga, Rafael; Romero, Rafael; Perea, Anselmo

2005-01-01

An in vitro assay measuring the antimicrobial activity of essential oils of Coridothymus capitatus (Spanish origanum), Satureja montana, Thymus mastichina (Spanish Origanum majorana), Thymus zygis (Spanish variety of Thymus vulgaris) and Origanum vulgare has been carried out against poultry origin strains of Escherichia coli, Salmonella enteritidis and Salmonella essen, and pig origin strains of enterotoxigenic E. coli (ETEC), Salmonella choleraesuis and Salmonella typhimurium. Using the broth microdilution method, all the essential oils showed an MIC > or = 2% (v/v) for the two strains of E. coli. The essential oil that showed the highest antimicrobial activity against the four strains of Salmonella was Origanum vulgare (MIC < or = 1% v/v), followed by Thymus zygis (MIC < or =2% v/v). Thymus mastichina inhibited all the microorganisms at the highest concentration, 4% (v/v), while the rest of the essential oils showed highly variable results. By chemotyping, higher inhibitory capacity was observed in the oils with a higher percentage of phenolic components (carvacrol and thymol) in comparison with oils containing the monoterpenic alcohol linalool. The results of this work confirm the antimicrobial activity of some essential oils, as well as their potential application in the treatment and prevention of poultry and pig diseases caused by salmonella.

In vitro analysis of the properties of Beiqishen tea.

PubMed

Blázovics, A; Szentmihályi, K; Lugasi, A; Balázs, A; Hagymási, K; Bányai, E; Then, M; Rapavi, E; Héthelyi, E

2003-10-01

Chinese Beiqishen tea was studied in an in vitro test system. Phytochemical screening, trace element analysis, and the analysis of antioxidant properties were carried out. Characteristic constituents were determined by chromatographic (capillary gas chromatography and GCQ Ion Trap mass spectrometry) and spectrometric (ultraviolet and UV-VIS) methods. Element concentrations were determined by inductively coupled plasma optical emission spectrometry. Antioxidant capacity was studied by spectrophotometric and luminometric techniques using a Berthold Lumat 9501 luminometer. Hydrogen-donating activity, reducing power, and total scavenger capacity were measured. Total polyphenol content was 20.77 +/- 0.52 g/100 g of drug; total flavonoid content was 0.485 +/- 0.036 g/100 g of drug; and tannin content was 9.063 +/- 0.782 g/100 g of drug. Caffeine content was 1.08 mg/100 g of drug. Essential oils were identified by gas chromatography: (+)-limonene (21%), p-cymene (1.7%), estragol (3.2%), beta-ocimene (1.4%), and thymol (2.6%). Metallic ion analysis showed significantly high concentrations of Al, As, Ba, Cr, Cu, Fe, Mn, Ni, and Ti in the drug. Antioxidant and scavenger properties were identified as a function of concentration. The tea infusion contained some non-desirable trace elements and caffeine in addition to polyphenols and tannins in high concentrations. Therefore, the consumption of this tea may involve risks.

Chemical Polymorphism of Origanum compactum Grown in All Natural Habitats in Morocco.

PubMed

Aboukhalid, Kaoutar; Lamiri, Abdeslam; Agacka-Mołdoch, Monika; Doroszewska, Teresa; Douaik, Ahmed; Bakha, Mohamed; Casanova, Joseph; Tomi, Félix; Machon, Nathalie; Faiz, Chaouki Al

2016-09-01

Origanum compactum L. (Lamiaceae) is one of the most important medicinal species in term of ethnobotany in Morocco. It is considered as a very threatened species as it is heavily exploited. Its domestication remains the most efficient way to safeguard it for future generations. For this purpose, wide evaluation of the existing variability in all over the Moroccan territory is required. The essential oils of 527 individual plants belonging to 88 populations collected from the whole distribution area of the species in Morocco were analyzed by GC/MS. The dominant constituents were carvacrol (0 - 96.3%), thymol (0 - 80.7%), p-cymene (0.2 - 58.6%), γ-terpinene (0 - 35.2%), carvacryl methyl ether (0 - 36.2%), and α-terpineol (0 - 25.8%). While in the Middle Atlas region and the Central Morocco mainly carvacrol type samples were found, much higher chemotypic diversity was encountered within samples from the north part of Morocco (occidental and central Rif regions). The high chemical polymorphism of plants offers a wide range for selection of valuable chemotypes, as a part of breeding and domestication programs of this threatened species. © 2016 Wiley-VHCA AG, Zürich.

Innovation of natural essential oil-loaded Orabase for local treatment of oral candidiasis

PubMed Central

Labib, Gihan S; Aldawsari, Hibah

2015-01-01

Purpose Oral candidiasis may be manifested in the oral cavity as either mild or severe oral fungal infection. This infection results from the overgrowth of Candida species normally existing in the oral cavity in minute amounts based on many predisposing factors. Several aspects have spurred the search for new strategies in the treatment of oral candidiasis, among which are the limited numbers of new antifungal drugs developed in recent years. Previous studies have shown that thyme and clove oils have antimycotic activities and have suggested their incorporation into pharmaceutical preparations. This study aimed to investigate the possibility of the incorporation and characterization of essential oils or their extracted active ingredients in Orabase formulations. Methods Orabase loaded with clove oil, thyme oil, eugenol, and thymol were prepared and evaluated for their antifungal activities, pH, viscosity, erosion and water uptake characteristics, mechanical properties, in vitro release behavior, and ex vivo mucoadhesion properties. Results All prepared bases showed considerable antifungal activity and acceptable physical characteristics. The release pattern from loaded bases was considerably slow for all oils and active ingredients. All bases showed appreciable adhesion in the in vitro and ex vivo studies. Conclusion The incorporation of essential oils in Orabase could help in future drug delivery design, with promising outcomes on patients’ well-being. PMID:26170621

Report on the Medicinal Use of Eleven Lamiaceae Species in Lebanon and Rationalization of Their Antimicrobial Potential by Examination of the Chemical Composition and Antimicrobial Activity of Their Essential Oils

PubMed Central

Khoury, Madona; Eparvier, Véronique; Ouaini, Naïm

2016-01-01

Many Lamiaceae species are consumed in the Lebanese cuisine as food or condiment and are largely used in the traditional medicine of Lebanon to treat various diseases, including microbial infections. In this article we report the traditional medicinal uses of eleven Lamiaceae species: Coridothymus capitatus L., Lavandula stoechas L., Lavandula angustifolia Mill., Mentha spicata L. subsp. condensata, Origanum syriacum L., Rosmarinus officinalis, Salvia fruticosa Miller., Satureja cuneifolia Ten., Satureja thymbra L., Thymbra spicata L., and Vitex agnus-castus L. and study the chemical composition and antimicrobial activity of their essential oils (EOs). Our survey showed that Lamiaceae species are mainly used against gastrointestinal disorders and microbial infections. Chemical analysis of the EOs obtained from these plants allowed us to identify seventy-five compounds describing more than 90% of the relative composition of each EO. Essential oils with high amounts of thymol and carvacrol possessed the strongest antimicrobial activity. As expected, these two compounds demonstrated an interesting antifungal efficacy against the filamentous fungus T. rubrum. Our results confirmed that some of the Lamiaceae species used in Lebanon ethnopharmacological practices as antimicrobial agents do possess antibacterial and antifungal potential consistent with their use in alternative or complementary medicine. PMID:28053641

Antimicrobial properties of nisin after glycation with lactose, maltodextrin and dextran and the thyme oil emulsions prepared thereof.

PubMed

Chen, Huaiqiong; Davidson, P Michael; Zhong, Qixin

2014-11-17

To clarify the reported conflicting antimicrobial activities of nisin after glycation, nisin was glycated with lactose, maltodextrin, and dextran at 70 °C and 50% relative humidity for 1-24 h. Nisin before and after glycation was studied for the first time to prepare thyme oil emulsions. The activity of glycated nisin and the thyme oil emulsions was tested in both tryptic soy broth (TSB) and 2% reduced fat milk. Results showed that nisin glycated with a smaller saccharide for a longer duration had a higher degree of glycation and the reduced number of positive charges lowered its antibacterial activity. The emulsified thyme oil had an additive effect with either glycated or native nisin against Listeria monocytogenes Scott A and Bacillus subtilis in TSB and 2% reduced fat milk. However, emulsions were less effective against L. monocytogenes Scott A in milk than same units of native nisin and same concentration of free thyme oil, likely due to the reduced availability of thymol and carvacrol, the main components of thyme oil. These results showed that glycation of nisin cannot broaden its antimicrobial activity and nisin is not a good compound to prepare emulsions of essential oils. Copyright © 2014 Elsevier B.V. All rights reserved.

Antimycotoxigenic characteristics of Rosmarinus officinalis and Trachyspermum copticum L. essential oils.

PubMed

Rasooli, Iraj; Fakoor, Mohammad Hadi; Yadegarinia, Davod; Gachkar, Latif; Allameh, Abdolamir; Rezaei, Mohammad Bagher

2008-02-29

Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Natural products may regulate the cellular effects of aflatoxins and evidence suggests that aromatic organic compounds of spices can control the production of aflatoxins. With a view to controlling aflatoxin production, the essential oils from Rosmarinus officinalis and Trachyspermum copticum L. were obtained by hydrodistillation. Antifungal activities of the oils were studied with special reference to the inhibition of Aspergillus parasiticus growth and aflatoxin production. Minimal inhibitory (MIC) and minimal fungicidal (MFC) concentrations of the oils were determined. T. copticum L. oil showed a stronger inhibitory effect than R. officinalis on the growth of A. parasiticus. Aflatoxin production was inhibited at 450 ppm of both oils with that of R. officinalis being stronger inhibitor. The oils were analyzed by GC and GC/MS. The major components of R. officinalis and T. copticum L. oils were Piperitone (23.65%), alpha-pinene (14.94%), Limonene (14.89%), 1,8-Cineole (7.43%) and Thymol (37.2%), P-Cymene (32.3%), gamma-Terpinene (27.3%) respectively. It is concluded that the essential oils could be safely used as preservative materials on some kinds of foods to protect them from toxigenic fungal infections.

Composition and antimicrobial activity of the essential oils of Laserpitium latifolium L. and L. ochridanum Micevski (Apiaceae).

PubMed

Popović, Višnja B; Petrović, Silvana D; Milenković, Marina T; Drobac, Milica M; Couladis, Maria A; Niketić, Marjan S

2015-01-01

The chemical composition and antimicrobial activity of essential oils of Laserpitium latifolium and L. ochridanum were investigated. The essential oils were isolated by steam distillation and characterized by GC-FID and GC/MS analyses. All essential oils were distinguished by high contents of monoterpenes, and α-pinene was the most abundant compound in the essential oils of L. latifolium underground parts and fruits (contents of 44.4 and 44.0%, resp.). The fruit essential oil was also rich in sabinene (26.8%). Regarding the L. ochridanum essential oils, the main constituents were limonene in the fruit oil (57.7%) and sabinene in the herb oil (25.9%). The antimicrobial activity of these essential oils as well as that of L. ochridanum underground parts, whose composition was reported previously, was tested by the broth-microdilution method against four Gram-positive and three Gram-negative bacteria and two Candida albicans strains. Except the L. latifolium underground-parts essential oil, the other investigated oils showed a high antimicrobial potential against Staphylococcus aureus, S. epidermidis, Micrococcus luteus, or Candida albicans (minimal inhibitory concentrations of 13.0-73.0 μg/ml), comparable to or even higher than that of thymol, which was used as reference compound. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

Innovation of natural essential oil-loaded Orabase for local treatment of oral candidiasis.

PubMed

Labib, Gihan S; Aldawsari, Hibah

2015-01-01

Oral candidiasis may be manifested in the oral cavity as either mild or severe oral fungal infection. This infection results from the overgrowth of Candida species normally existing in the oral cavity in minute amounts based on many predisposing factors. Several aspects have spurred the search for new strategies in the treatment of oral candidiasis, among which are the limited numbers of new antifungal drugs developed in recent years. Previous studies have shown that thyme and clove oils have antimycotic activities and have suggested their incorporation into pharmaceutical preparations. This study aimed to investigate the possibility of the incorporation and characterization of essential oils or their extracted active ingredients in Orabase formulations. Orabase loaded with clove oil, thyme oil, eugenol, and thymol were prepared and evaluated for their antifungal activities, pH, viscosity, erosion and water uptake characteristics, mechanical properties, in vitro release behavior, and ex vivo mucoadhesion properties. All prepared bases showed considerable antifungal activity and acceptable physical characteristics. The release pattern from loaded bases was considerably slow for all oils and active ingredients. All bases showed appreciable adhesion in the in vitro and ex vivo studies. The incorporation of essential oils in Orabase could help in future drug delivery design, with promising outcomes on patients' well-being.

Sub-lethal effects of essential oil of Lippia sidoides on drywood termite Cryptotermes brevis (Blattodea: Termitoidea).

PubMed

Santos, Abraão Almeida; de Oliveira, Bruna Maria Santos; Melo, Carlisson Ramos; Lima, Ana Paula Santana; Santana, Emile Dayara Rabelo; Blank, Arie Fitzgerald; Picanço, Marcelo Coutinho; Araújo, Ana Paula Albano; Cristaldo, Paulo Fellipe; Bacci, Leandro

2017-11-01

The drywood termite Cryptotermes brevis (Walker, 1853) (Kalotermitidae) is one of the most important wood structural pest in the world. Substances from the secondary metabolism of plants (e.g., essential oils) have been considered an environmentally safer form of control for urban pests, such as termites. In the present study, we analyzed the lethal and sub-lethal effects of essential oil of Lippia sidoides and its major components on C. brevis pseudergates in two routes of exposure (contact and fumigation). The essential oil of L. sidoides and thymol were more toxic to C. brevis pseudergates when applied by contact (LD 50 = 9.33 and 8.20µgmg -1 , respectively) and by fumigation (LC 50 = 9.10 and 23.6µLL -1 , respectively). In general, treatments changed the individual and collective behaviors of C. brevis pseudergates, as well as the displacement and walking speed. The essential oil of L. sidoides and its major components showed a high potential to control C. brevis pseudergates, due to the bioactivity in the two routes of exposure and the sub-lethal effects on the behavior and walking, important activities for the cohesion of C. brevis colonies. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of chlorhexidine, essential oils and herbal medicines (Salvia, Chamomile, Calendula) on human fibroblast in vitro.

PubMed

Wyganowska-Swiatkowska, Marzena; Urbaniak, Paulina; Szkaradkiewicz, Anna; Jankun, Jerzy; Kotwicka, Malgorzata

2016-01-01

Antiseptic rinses have been successfully used in inflammatory states of the gums and oral cavity mucosa. Antibacterial effects of chlorhexidine, essential oils and some herbs are well documented. Reaction of host tissue to these substances has much poorer documentation. The aim of the study was to analyse the influence of chlorhexidine (CHX), essential oil (EO: thymol, 0.064%; eucalyptol, 0.092%; methyl salicylate, 0.060%; menthol, 0.042%) mouth rinses and salvia, chamomile and calendula brews on fibroblast biology in vitro. The human fibroblast CCD16 line cells were cultured in incubation media which contained the examined substances. After 24 and 48 hours, the cell morphology, relative growth and apoptosis were evaluated. Exposure of fibroblasts to CHX, EO or salvia caused various changes in cell morphology. Cells cultured for 48 hours with CHX revealed a noticeably elongated shape of while cells cultured in high EO concentration or with salvia were considerably smaller and contracted with fewer projections. Chlorhexidine, EO and salvia reduced the fibroblast proliferation rate and stimulated cell death. Both reactions to EO were dose dependent. Cells exposure to chamomile or calendula brews did not change morphology or proliferation of fibroblasts. The results of this in vitro study showed that in contrast to chamomile and calendula, the brews of EO, CHX or salvia had a negative influence on fibroblast biology.

Effects of chlorhexidine, essential oils and herbal medicines (Salvia, Chamomile, Calendula) on human fibroblast in vitro

PubMed Central

Urbaniak, Paulina; Szkaradkiewicz, Anna; Jankun, Jerzy; Kotwicka, Malgorzata

2016-01-01

Antiseptic rinses have been successfully used in inflammatory states of the gums and oral cavity mucosa. Antibacterial effects of chlorhexidine, essential oils and some herbs are well documented. Reaction of host tissue to these substances has much poorer documentation. The aim of the study was to analyse the influence of chlorhexidine (CHX), essential oil (EO: thymol, 0.064%; eucalyptol, 0.092%; methyl salicylate, 0.060%; menthol, 0.042%) mouth rinses and salvia, chamomile and calendula brews on fibroblast biology in vitro. The human fibroblast CCD16 line cells were cultured in incubation media which contained the examined substances. After 24 and 48 hours, the cell morphology, relative growth and apoptosis were evaluated. Exposure of fibroblasts to CHX, EO or salvia caused various changes in cell morphology. Cells cultured for 48 hours with CHX revealed a noticeably elongated shape of while cells cultured in high EO concentration or with salvia were considerably smaller and contracted with fewer projections. Chlorhexidine, EO and salvia reduced the fibroblast proliferation rate and stimulated cell death. Both reactions to EO were dose dependent. Cells exposure to chamomile or calendula brews did not change morphology or proliferation of fibroblasts. The results of this in vitro study showed that in contrast to chamomile and calendula, the brews of EO, CHX or salvia had a negative influence on fibroblast biology. PMID:27536196

Laboratory and Simulated Field Bioassays to Evaluate Larvicidal Activity of Pinus densiflora Hydrodistillate, Its Constituents and Structurally Related Compounds against Aedes albopictus, Aedes aegypti and Culex pipiens pallens in Relation to Their Inhibitory Effects on Acetylcholinesterase Activity

PubMed Central

Lee, Dong Chan; Ahn, Young-Joon

2013-01-01

The toxicity of Pinus densiflora (red pine) hydrodistillate, its 19 constituents and 28 structurally related compounds against early third-instar larvae of Aedes albopictus (Ae. albopictus), Aedes aegypti (Ae. aegypti) and Culex pipiens palles (Cx. p. pallens) was examined using direct-contact bioassays. The efficacy of active compounds was further evaluated in semi-field bioassays using field-collected larval Cx. p. pallens. Results were compared with those of two synthetic larvicides, temephos and fenthion. In laboratory bioassays, Pinus densiflora hydrodistillate was found to have 24 h LC50 values of 20.33, 21.01 and 22.36 mg/L against larval Ae. albopictus, Ae. aegypti and Cx. p. pallens respectively. Among the identified compounds, thymol, δ-3-carene and (+)-limonene exhibited the highest toxicity against all three mosquito species. These active compounds were found to be nearly equally effective in field trials as well. In vitro bioassays were conducted to examine the acetylcholinesterase (AChE) inhibitory activity of 10 selected compounds. Results showed that there is a noticeable correlation between larvicidal activity and AChE inhibitory activity. In light of global efforts to find alternatives for currently used insecticides against disease vector mosquitoes, Pinus densiflora hydrodistillate and its constituents merit further research as potential mosquito larvicides. PMID:26464387

Oregano (Lippia graveolens) essential oil added within pectin edible coatings prevents fungal decay and increases the antioxidant capacity of treated tomatoes.

PubMed

Rodriguez-Garcia, Isela; Cruz-Valenzuela, M Reynaldo; Silva-Espinoza, Brenda A; Gonzalez-Aguilar, Gustavo A; Moctezuma, Edgar; Gutierrez-Pacheco, M Melissa; Tapia-Rodriguez, Melvin R; Ortega-Ramirez, Luis A; Ayala-Zavala, J Fernando

2016-08-01

Tomato is a fruit widely consumed due to its flavor and nutritional value; however, it is susceptible to fungi contamination. Oregano essential oil (OEO) is a fungicide whose constituents are volatile; therefore, their incorporation within edible coatings can protect them and maintain their efficacy. In this context, this study evaluated the effect of OEO applied within pectin coatings on the inhibition of Alternaria alternata growth, antioxidant content and sensorial acceptability of tomatoes. The major volatile compounds of OEO were carvacrol (47.41%), p-cymene (26.44%) and thymol (3.02%). All the applied OEO concentrations (15.7, 25.9 and 36.1 g L(-1) ) inhibited the in vitro growth of A. alternata, whereas the in vivo effective concentrations were 25.9 and 36.1 g L(-1) . Additionally, there was an increment of total phenols and antioxidant activity in coated tomatoes compared to controls. Aroma acceptability of tomatoes was not affected by the pectin-OEO coating; additionally, the pectin, pectin-OEO 15.7 g L(-1) treatments and control tomatoes showed higher flavor acceptability than those coated with pectin-OEO 25.9 and 36.1 g L(-1) . Pectin-OEO coatings showed antifungal effect and increased the antioxidant activity without negative effects on the sensorial acceptability of tomatoes. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Essential oils of culinary herbs and spices display agonist and antagonist activities at human aryl hydrocarbon receptor AhR.

PubMed

Bartoňková, Iveta; Dvořák, Zdeněk

2018-01-01

Essential oils (EOs) of culinary herbs and spices are used to flavor, color and preserve foods and drinks. Dietary intake of EOs is significant, deserving an attention of toxicologists. We examined the effects of 31 EOs of culinary herbs and spices on the transcriptional activity of human aryl hydrocarbon receptor (AhR), which is a pivotal xenobiotic sensor, having also multiple roles in human physiology. Tested EOs were sorted out into AhR-inactive ones (14 EOs) and AhR-active ones, including full agonists (cumin, jasmine, vanilla, bay leaf), partial agonists (cloves, dill, thyme, nutmeg, oregano) and antagonists (tarragon, caraway, turmeric, lovage, fennel, spearmint, star anise, anise). Major constituents (>10%) of AhR-active EOs were studied in more detail. We identified AhR partial agonists (carvacrol, ligustilide, eugenol, eugenyl acetate, thymol, ar-turmerone) and antagonists (trans-anethole, butylidine phtalide, R/S-carvones, p-cymene), which account for AhR-mediated activities of EOs of fennel, anise, star anise, caraway, spearmint, tarragon, cloves, dill, turmeric, lovage, thyme and oregano. We also show that AhR-mediated effects of some individual constituents of EOs differ from those manifested in mixtures. In conclusion, EOs of culinary herbs and spices are agonists and antagonists of human AhR, implying a potential for food-drug interactions and interference with endocrine pathways. Copyright © 2017 Elsevier Ltd. All rights reserved.

Combined treatment of Thymus vulgaris L., Rosmarinus officinalis L. and Myrtus communis L. essential oils against Salmonella typhimurium: Optimization of antibacterial activity by mixture design methodology.

PubMed

Fadil, Mouhcine; Fikri-Benbrahim, Kawtar; Rachiq, Saad; Ihssane, Bouchaib; Lebrazi, Sara; Chraibi, Marwa; Haloui, Taoufik; Farah, Abdellah

2018-05-01

To increase the sensibility of Salmonella typhimurium strain, a mixture of Thymus vulgaris L. (T. vulgaris L.), Rosmarinus officinalis L. (R. officinalis L.) and Myrtus communis L. (M. communis L.) essential oils (EOs) was used in combined treatment by experimental design methodology (mixture design). The chemical composition of EOs was firstly identified by GC and GC/MS and their antibacterial activity was evaluated. The results of this first step have shown that thymol and borneol were the major compounds in T. vulgaris and M. communis L. EOs, respectively, while 1,8-cineole and α-pinene were found as major compounds in R. officinalis L. The same results have shown a strong antibacterial activity of T. vulgaris L. EO followed by an important power of M. communis L. EO against a moderate activity of R. officinalis L. EO. Besides, 1/20 (v/v) was the concentration giving a strain response classified as sensitive. From this concentration, the mixture design was performed and analyzed. The optimization of mixtures antibacterial activities has highlighted the synergistic effect between T. vulgaris L. and M. communis L. essential oils. A formulation comprising 55% of T. vulgaris L. and 45% of M. communis L. essential oils, respectively, can be considered for the increase of Salmonella typhimurium sensibility. Copyright © 2017 Elsevier B.V. All rights reserved.

Herbs and spices: characterization and quantitation of biologically-active markers for routine quality control by multiple headspace solid-phase microextraction combined with separative or non-separative analysis.

PubMed

Sgorbini, Barbara; Bicchi, Carlo; Cagliero, Cecilia; Cordero, Chiara; Liberto, Erica; Rubiolo, Patrizia

2015-01-09

Herbs and spices are used worldwide as food flavoring, thus determination of their identity, origin, and quality is mandatory for safe human consumption. An analysis strategy based on separative (HS-SPME-GC-MS) and non-separative (HS-SPME-MS) approaches is proposed for the volatile fraction of herbs and spices, for quality control and to quantify the aromatic markers with a single analysis directly on the plant material as such. Eight-to-ten lots of each of the following herbs/spices were considered: cloves (Syzygium aromaticum (L.) Merr. & Perry), American peppertree (Schinus molle L.), black pepper and white pepper (Piper nigrum L.), rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.) and thyme (Thymus vulgaris L.). Homogeneity, origin, and chemotypes of the investigated lots of each herb/spice were defined by fingerprinting, through statistical elaboration with principal component analysis (PCA). Characterizing aromatic markers were directly quantified on the solid matrix through multiple headspace extraction-HS-SPME (MHS-SPME). Reliable results were obtained with both separative and non-separative methods (where the latter were applicable); the two were in full agreement, RSD% ranging from 1.8 to 7.7% for eugenol in cloves, 2.2-18.4% for carvacrol+thymol in thyme, and 3.1-16.8% for thujones in sage. Copyright © 2014 Elsevier B.V. All rights reserved.

Chemical composition, antibacterial and antioxidant activities of leaf essential oil and extracts of Metasequioa glyptostroboides Miki ex Hu.

PubMed

Bajpai, Vivek K; Al-Reza, Sharif M; Choi, Ung Kyu; Lee, Jong Hwi; Kang, Sun Chul

2009-08-01

The aims of this study were to analyze the chemical composition of leaf essential oil of Metasequioa glyptostroboides Miki, and to test the efficacy of oil and extracts (hexane, chloroform, ethyl acetate and methanol) against food spoilage and food-borne pathogenic bacteria and their antioxidant activity. The GC-MS analysis revealed 49 compounds representing 94.62% of the total oil containing 2-butaneone (30.6%), cyclopentane (15.1%), beta-myrcene (13.29%), cyclobutane (7.67%), furan (3%), valeramide (2.81%), borneol (1.2%), beta-farnesene (1.67%), thymol (1.44%) and alpha-pinene (1.46%) as major components. The oil (1000 microg/disc), and extracts (1500 microg/disc) exhibited promising antibacterial effect as a diameter of zones of inhibition (10-18 and 7-13 mm), respectively. MIC values of oil and the extracts were ranged 125-2000 and 250 to <2000 microg/ml, respectively. Also the oil had strong antibacterial effect on the viable counts. Scanning electron microscopic study demonstrated potential detrimental effect of the oil on the morphology of S. aureus KCTC1916. The free radical scavenging activities of the oil and ethyl acetate extract were found to be 11.32 and 19.12 microg/ml, respectively. Also the ethyl acetate extract revealed the highest phenolic contents (85.17 mg/g of dry wt) as compared to the other extracts.

Dual stimuli responsive self-reporting material for chemical reservoir coating

NASA Astrophysics Data System (ADS)

Lee, Tae Hee; Song, Young Kyu; Park, Sun Hee; Park, Young Il; Noh, Seung Man; Kim, Jin Chul

2018-03-01

In this study, we introduce a novel dual stimuli responsive self-reporting thiol-epoxy thermoset (DSRTET) coatings which can detect both crack occurrence and pH variation. For crack detection, microcapsule containing tetraphenylethylene (TPE) which exhibits aggregation induced emission (AIE) effect was prepared via multi-step emulsion polymerization and dispersed in DSRTET coatings. For pH variation detection, commercial thymol blue as a pH indicator was added into the polymer matrix. The effect of microcapsule contents in DSRTET on their curing behavior, material properties, and crack sensitivity was characterized using an oscillatory rheology, rigid body pendulum test (RPT), nano-indentation test (NST), universal test machine (UTM) and scratch tester. It was revealed that crack sensitivity of DSRTET coatings was greatly influenced by material properties as well as microcapsule content. The color transition of DSRTET coatings in response to acid or base solution were quantitatively investigated using a multi-angle spectrophotometer after simple acid and base solution drop tests. The color of DSRTET coatings changed from a pale green to red for acidic solution and to blue for basic solution. Finally, The DSRTET used in this study was applied to laboratory scale chemical reservoirs in order to verify the potential as a dual stimuli response self-reporting coating which can detect both crack in coating material and chemical spill caused by the leakage or breakage of the reservoir part.

Chemical compositions, antioxidant and antimicrobial properties of Ziziphora clinopodioides Lam. essential oils collected from different parts of Iran.

PubMed

Shahbazi, Yasser

2017-10-01

The aims of the present study were to investigate chemical compositions, antioxidant and antimicrobial properties of Ziziphora clinopodioides essential oils (ZEOs) collected from four provinces in western Iran (Ilam, Lorestan, Kermanshah and Kurdestan). Carvacrol was the most abundant constituent in the flower, stem and leaf oil samples of Ilam, Lorestan and Kermanshah regions by 73.12-74.29%, 66.47-66.89% and 65.11-65.32%, respectively. The most abundant components in Kurdestan sample were thymol (55.32-55.60%), followed by γ -terpinene (24.45-24.56%), p -cymene (10.21-10.25%) and α -terpinene (2.75-2.77%). The ZEO inhibited the growth of Listeria monocytogenes , Salmonella typhimurium , Escherichia coli O157:H7, Bacillus subtilis , Bacillus cereus and Staphylococcus aureus at MIC values between 0.03 and 0.04%. Kermanshah oil sample had a higher 1,1-diphenyl-2-picrylhydrazyl radical scavenging (0.30-0.31 mg/ml), ability to prevent the bleaching of β-carotene (0.09-0.1 mg/ml), ferric reducing power (0.40-0.42 mg/ml) and thiobarbituric acid (0.004-0.006 Meq of malondialdehyde/g) values than that of ZEOs from Ilam, Kurdestan and Lorestan. The strong in vitro antimicrobial and antioxidant activities supports the traditional use of ZEO in the treatments of gastrointestinal diseases.

Biomolecular characterization of wild sicilian oregano: phytochemical screening of essential oils and extracts, and evaluation of their antioxidant activities.

PubMed

Tuttolomondo, Teresa; La Bella, Salvatore; Licata, Mario; Virga, Giuseppe; Leto, Claudio; Saija, Antonella; Trombetta, Domenico; Tomaino, Antonio; Speciale, Antonio; Napoli, Edoardo M; Siracusa, Laura; Pasquale, Andrea; Curcuruto, Giusy; Ruberto, Giuseppe

2013-03-01

An extensive survey of wild Sicilian oregano was made. A total of 57 samples were collected from various sites, followed by taxonomic characterization from an agronomic perspective. Based on morphological and production characteristics obtained from the 57 samples, cluster analysis was used to divide the samples into homogeneous groups, to identify the best biotypes. All samples were analyzed for their phytochemical content, applying a cascade-extraction protocol and hydrodistillation, to obtain the non volatile components and the essential oils, respectively. The extracts contained thirteen polyphenol derivatives, i.e., four flavanones, seven flavones, and two organic acids. Their qualitative and quantitative characterization was carried out by LC/MS analyses. The essential oils were characterized using a combination of GC-FID and GC/MS analyses; a total of 81 components were identified. The major components of the oils were thymol, p-cymene, and γ-terpinene. Cluster analysis was carried out on both phytochemical profiles and resulted in the division of the oregano samples into different chemical groups. The antioxidant activity of the essential oils and extracts was investigated by the Folin-Ciocalteau (FC) colorimetric assay, by UV radiation-induced peroxidation in liposomal membranes (UV-IP test), and by determining the O(2)(∙-)-scavenging activity. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

Anthelmintic activity of Croton zehntneri and Lippia sidoides essential oils.

PubMed

Camurça-Vasconcelos, A L F; Bevilaqua, C M L; Morais, S M; Maciel, M V; Costa, C T C; Macedo, I T F; Oliveira, L M B; Braga, R R; Silva, R A; Vieira, L S

2007-09-30

Because of the development of anthelmintic resistant populations, the search for new drugs is essential to maintain the productivity of small ruminants. The aim of this study was to evaluate the anthelmintic activity of Croton zehntneri and Lippia sidoides essential oils and their major constituents, anethole and thymol. The effects of these oils and their constituents were determined by in vitro assays with the eggs and larvae of the sheep gastrointestinal nematode Haemonchus contortus. The two essential oils were evaluated on intestinal nematodes of mice at 800 mg kg(-1) dose. In the last experiment, the mice were treated with larger doses of L. sidoides, 1200 and 1600 mg kg(-1). The essential oils and their constituents prevented more than 98% of the H. contortus eggs from hatching at a concentration of 1.25 mg ml(-1) and inhibited more than 90% of H. contortus larval development at a concentration of 10 mg ml(-1). At a concentration of 800 mg kg(-1), the two essential oils were 46.3% and 11.64% effective against Syphacia obvelata and Aspiculuris tetraptera. At 1200 and 1600 mg kg(-1), L. sidoides essential oil's efficacy on the mouse worm burden was 57.6% and 68.9%, respectively. The fact that L. sidoides essential oil was almost 70% effective against mouse intestinal nematodes indicates it should be evaluated against gastrointestinal nematodes of sheep and goats.

Chemical composition and biological evaluation of the volatile constituents from the aerial parts of Nephrolepis exaltata (L.) and Nephrolepis cordifolia (L.) C. Presl grown in Egypt.

PubMed

El-Tantawy, Mona E; Shams, Manal M; Afifi, Manal S

2016-01-01

The essential oil from the aerial parts of Nephrolepis exaltata and Nephrolepis cordifolia obtained by hydro-distillation were analyzed by gas chromatography/ mass spectrometry. The essential oils exhibited potential antibacterial and antifungal activities against a majority of the selected microorganisms. NEA oil showed promising cytotoxicity in breast, colon and lung carcinoma cells. The results presented indicate that NEA oil could be useful alternative for the treatment of dermatophytosis. Comparative investigation of hydro-distilled volatile constituents from aerial parts (A) of Nephrolepis exaltata (NE) and Nephrolepis cordifolia (NC) (Family Nephrolepidaceae) was carried out. Gas chromatography/mass spectrometry revealed that oils differ in composition and percentages of components. Oxygenated compounds were dominant in NEA and NCA. 2,4-Hexadien-1-ol (16.1%), nonanal (14.4%), β-Ionone (6.7%) and thymol (2.7%) were predominant in NEA. β-Ionone (8.0%), eugenol (7.2%) and anethol (4.6%) were the main constituents in NCA. Volatile samples were screened for their antibacterial and antifungal activities using agar diffusion method and minimum inhibitory concentrations. The cytotoxic activity was evaluated using viability assay in breast (MCF-7), colon (HCT-116) and lung carcinoma (A-549) cells by the MTT assay. The results revealed that NEA oil exhibited potential antimicrobial activity against most of the tested organisms and showed promising cytotoxicity.

Antimicrobial activity of four essential oils against pigmenting Pseudomonas fluorescens and biofilmproducing Staphylococcus aureus of dairy origin

PubMed Central

Pedonese, Francesca; Fratini, Filippo; Pistelli, Luisa; Porta, Federica Maria; Ciccio, Pierluigi Di; Fischetti, Roberto; Turchi, Barbara; Nuvoloni, Roberta

2017-01-01

Essential oils (EOs) are mixtures of secondary metabolites of plant origin with many useful properties, among which the antimicrobial activity is also of interest for the food industry. EOs can exert their antimicrobial potential both directly, in food products and active packaging, and indirectly, as sanitizing and anti-biofilm agents of food facility surfaces. Aim of this research was to evaluate the antimicrobial activity of four EOs (bergamot, cinnamon, manuka and thyme) against Pseudomonas fluorescens and Staphylococcus aureus isolated from milk and dairy products. The chemical composition of EOs was evaluated by Gas Chromatography-Mass Spectrometry analysis. Minimum Inhibitory Concentration values were determined by a microplate method against 9 Ps. fluorescens from marketed mozzarella with blue discoloration defect, and 3 biofilm-producing S. aureus from milk. Reference ATCC strains were included. Pigment production activity by Ps. fluorescens was assessed both in culture and in cheese. EOs of manuka (leptospermone 23%) and thyme (carvacrol 30%, pcymene 20%, thymol 15%) showed the highest antimicrobial activity against S. aureus, MIC values were 0.012%-0.024% and 0.024% v/v, respectively; meanwhile EOs from thyme and cinnamon (cinnamaldehyde 55%) exhibited the best activity against Ps. fluorescens with MIC values of 0.098%-0.195% and 0.195%-0.391% v/v, respectively. The antimicrobial activity of these EOs is promising and they could be exploited in the dairy production chain. PMID:29564238

Chemical composition and biological activity of the essential oil from Thymus lanceolatus.

PubMed

Khadir, Abdelmounaim; Sobeh, Mansour; Gad, Haidy A; Benbelaid, Fethi; Bendahou, Mourad; Peixoto, Herbenya; Sporer, Frank; Ashour, Mohamed L; Wink, Michael

2016-01-01

Thymus lanceolatus is a rare species, which grows wild in Algeria and Tunis. It is used traditionally as a drink and to flavor and preserve meat and poultry. The composition of the essential oil was determined by GLC/FID and GLC/MS. Forty-nine components were identified and quantified, accounting for 96.75% of the total detected components in the oil. The oxygenated monoterpenes (74.85%) constitute the major class of volatile secondary metabolites in the oil. Thymol was the most abundant constituent (69.61%) followed by γ-terpinene (8.38%). The antioxidant activity was evaluated using both diphenylpicrylhydrazyl (DPPH˙) reduction and 2-deoxyribose (2-DR) degradation prevention methods. The oil showed a very potent antioxidant activity with IC(50) values of 0.20 ± 0.07 and 4.96 ± 0.39 μg/mL for the DPPH˙ and 2-DR methods, respectively. The antimicrobial activity of the oil was assessed using the agar diffusion method, and the in vitro cytotoxicity on five different cancer cells was examined using the MTT assay. The oil revealed promising inhibitory activity against Gram positive bacteria, especially Bacillus subtilis and Streptococcus pyogenes with an MIC value of 62.5 μg/mL. Additionally, the highest cytotoxic activity was observed against the HL-60 cells with an IC(50) of 113.5 μg/mL. These results validate some of their traditional uses in food preservation.

Chitosan-Starch Films with Natural Extracts: Physical, Chemical, Morphological and Thermal Properties

PubMed Central

Díaz-Zavala, Nancy P.; Melo-Banda, José A.; García-Alamilla, Ricardo; Martínez-Hernández, Ana L.; Zapién-Castillo, Samuel

2018-01-01

The aim of this study is to analyze the properties of a series of polysaccharide composite films, such as apparent density, color, the presence of functional groups, morphology, and thermal stability, as well as the correlation between them and their antimicrobial and optical properties. Natural antioxidants such as anthocyanins (from cranberry; blueberry and pomegranate); betalains (from beetroot and pitaya); resveratrol (from grape); and thymol and carvacrol (from oregano) were added to the films. Few changes in the position and intensity of the FTIR spectra bands were observed despite the low content of extract added to the films. Due to this fact, the antioxidants were extracted and identified by spectroscopic analysis; and they were also quantified using the Folin-Denis method and a gallic acid calibration curve, which confirmed the presence of natural antioxidants in the films. According to the SEM analysis, the presence of natural antioxidants has no influence on the film morphology because the stretch marks and white points that were observed were related to starch presence. On the other hand, the TGA analysis showed that the type of extract influences the total weight loss. The overall interpretation of the results suggests that the use of natural antioxidants as additives for chitosan-starch film preparation has a prominent impact on most of the critical properties that are decisive in making them suitable for food-packing applications. PMID:29329275

Chemical Composition, Antimicrobial Activity, and Mode of Action of Essential Oils against Paenibacillus larvae, Etiological Agent of American Foulbrood on Apis mellifera.

PubMed

Pellegrini, María C; Alonso-Salces, Rosa M; Umpierrez, María L; Rossini, Carmen; Fuselli, Sandra R

2017-04-01

This study aimed to characterize the chemical composition of Aloysia polystachia, Acantholippia seriphioides, Schinus molle, Solidago chilensis, Lippia turbinata, Minthostachys mollis, Buddleja globosa, and Baccharis latifolia essential oils (EOs), and to evaluate their antibacterial activities and their capacity to provoke membrane disruption in Paenibacillus larvae, the bacteria that causes the American Foulbrood (AFB) disease on honey bee larvae. The relationship between the composition of the EOs and these activities on P. larvae was also analyzed. Monoterpenes were the most abundant compounds in all EOs. All EOs showed antimicrobial activity against P. larvae and disrupted the cell wall and cytoplasmic membrane of P. larvae provoking the leakage of cytoplasmic constituents (with the exception of B. latifolia EO). While, the EOs' antimicrobial activity was correlated most strongly to the content of pulegone, carvone, (Z)-β-ocimene, δ-cadinene, camphene, terpinen-4-ol, elemol, β-pinene, β-elemene, γ-cadinene, α-terpineol, and bornyl acetate; the volatiles that better explained the membrane disruption were carvone, limonene, cis-carvone oxide, pentadecane, trans-carvyl acetate, trans-carvone oxide, trans-limonene oxide, artemisia ketone, trans-carveol, thymol, and γ-terpinene (positively correlated) and biciclogermacrene, δ-2-carene, verbenol, α-pinene, and α-thujene (negatively correlated). The studied EOs are proposed as natural alternative means of control for the AFB disease. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Antifungal activity of essential oils extract from Origanum floribundum Munby, Rosmarinus officinalis L. and Thymus ciliatus Desf. against Candida albicans isolated from bovine clinical mastitis.

PubMed

Ksouri, S; Djebir, S; Bentorki, A A; Gouri, A; Hadef, Y; Benakhla, A

2017-06-01

The aim of this study is to limit the antibiotic use in mastitis treatment and to find other alternatives. The antifungal activity of the essential oils from Origanum floribundum Munby., Rosmarinus officinalis L. and Thymus ciliatus Desf. is studied in the present work against a Candida albicans reference strain and ten C. albicans isolated strains from bovine clinical mastitis. Essential oils were extracted by hydrodistillation technique using Clevenger apparatus. Their chromatographic analysis was performed with a Gas Chromatograph/Mass Spectrometer (GC/MS). Antifungal activities of essential oils were investigated by macrobroth method of dilution in tubes to determine the Minimum Inhibitory Concentrations (MIC 80%). Analysis of the essential oil showed chemical profile dominated by thymol (50.47 and 62.41%) and P-cymene (24.22 and 15.51%) in the oregano and the thyme respectively, 1, 8-cineol (31.50%) and α-pinene (18.33%) in Rosemary. The three essential oils revealed highly effective anticandidal activity, with an MIC of 80% values ranged from 15.02 to 31.08μg/mL. These results suggest that essential oils studied can be real alternatives in the control of mastitis fungi but deserving studies more in-depth and detailed on their application in vivo. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Design and characterization of a plastic optical fiber pH sensor

NASA Astrophysics Data System (ADS)

Ferreira, Licínio; Simões, Pedro; Carvalho, Rui S.; Lopes, Paulo; Ferreira, Mário

2013-11-01

In this paper are present the design and characterization of a pH sensor using plastic optical fiber (POF) technology and a material produced by the sol-gel process with TEOS (tetraethyl orthosilicate) to immobilize universal indicator of pH (comprised of Thymol Blue, Methyl Red, Bromothymol Blue and Phenolphthalein) inside the silica matrix. This matrix is positioned between two extensions of plastic optical fiber tightly positioned at each side with both fibers aligned and sharing a common optical axis. This set will work as a pH sensor since the matrix embedded with indicator and in the presence of a solution (basic or acid solution) will change the optical transmittance properties. The optical source is a superluminescent white LED and the receiver is a photodiode having a good and linear responsivity in the visible spectrum. This pH sensitive matrix has large pores which allow the diffusion of the surrounding fluid molecules into the matrix and thus the close contact of these to the indicator molecules. This contact causes the change of color of the whole matrix allowing proper colorimetric detection by the photodiode. This variation of color associated with the detector wavelength linear response is the base of operation of the proposed device. This pH sensor presents many advantages over the standard and commercial pH meters namely, lightweight, portability and a low cost.

Characterization of Essential Oils Obtained from Abruzzo Autochthonous Plants: Antioxidant and Antimicrobial Activities Assessment for Food Application

PubMed Central

Pellegrini, Marika; Chaves-López, Clemencia; Mazzarrino, Giovanni; D’Amato, Serena; Lo Sterzo, Claudio

2018-01-01

In the present study, the essential oils (EOs) of some officinal plants from Abruzzo territory (Italy) were evaluated for their antimicrobial and antioxidant activities and their volatile fraction chemical characterization. The EOs were extracted from Rosmarinus officinalis, Origanum vulgare, Salvia officinalis, Mentha piperita, Allium sativum, Foeniculum vulgare, Satureja montana, Thymus vulgaris and Coriandrum sativum seeds. The antimicrobial activity was screened against thirteen Gram-positive and Gram-negative strains to determine the Minimal Inhibitory Concentration (MIC). The total phenolic content (TPC) and the antioxidant capacity (AOC) were assessed by means of Folin-Ciocâlteu method, and Trolox Equivalent Antioxidant Capacity with 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (TEAC/ABTS), Ferric Reducing Antioxidant Power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays respectively. Among the nine EOs tested, T. vulgaris, S. montana, O. vulgare and C. sativum EOs showed MIC values ranging from 0.625 to 5 μL/mL. The AOC and TPC results for these species were also interesting. The major components for these EOs were thymol for T. vulgaris (44%) and O. vulgare (40%), linalool (77%) for C. sativum, and carvacrol for S. montana (54%). The results allowed the study to establish that these EOs are good candidates for potential application as biopreservatives in foods and/or food manufacture environments. PMID:29393893

Plant essential oils and allied volatile fractions as multifunctional additives in meat and fish-based food products: a review.

PubMed

Patel, Seema

2015-01-01

Essential oils are concentrated aromatic volatile compounds derived from botanicals by distillation or mechanical pressing. They play multiple, crucial roles as antioxidants, food pathogen inhibitors, shelf-life enhancers, texture promoters, organoleptic agents and toxicity-reducing agents. For their versatility, they appear promising as food preservatives. Several research findings in recent times have validated their potential as functional ingredients in meat and fish processing. Among the assortment of bioactive compounds in the essential oils, p-cymene, thymol, eugenol, carvacrol, isothiocyanate, cinnamaldehyde, cuminaldehyde, linalool, 1,8-cineol, α-pinene, α-terpineol, γ-terpinene, citral and methyl chavicol are most familiar. These terpenes (monoterpenes and sesquiterpenes) and phenolics (alcohols, esters, aldehydes and ketones) have been extracted from culinary herbs such as oregano, rosemary, basil, coriander, cumin, cinnamon, mint, sage and lavender as well as from trees such as myrtle, fir and eucalyptus. This review presents essential oils as alternatives to conventional chemical additives. Their synergistic actions with modified air packaging, irradiation, edible films, bacteriocins and plant byproducts are discussed. The decisive roles of metabolic engineering, microwave technology and metabolomics in quality and quantity augmentation of essential oil are briefly mooted. The limitations encountered and strategies to overcome them have been illuminated to pave way for their enhanced popularisation. The literature has been mined from scientific databases such as Pubmed, Pubchem, Scopus and SciFinder.

Chitosan-Starch Films with Natural Extracts: Physical, Chemical, Morphological and Thermal Properties.

PubMed

Lozano-Navarro, Jessica I; Díaz-Zavala, Nancy P; Velasco-Santos, Carlos; Melo-Banda, José A; Páramo-García, Ulises; Paraguay-Delgado, Francisco; García-Alamilla, Ricardo; Martínez-Hernández, Ana L; Zapién-Castillo, Samuel

2018-01-12

The aim of this study is to analyze the properties of a series of polysaccharide composite films, such as apparent density, color, the presence of functional groups, morphology, and thermal stability, as well as the correlation between them and their antimicrobial and optical properties. Natural antioxidants such as anthocyanins (from cranberry; blueberry and pomegranate); betalains (from beetroot and pitaya); resveratrol (from grape); and thymol and carvacrol (from oregano) were added to the films. Few changes in the position and intensity of the FTIR spectra bands were observed despite the low content of extract added to the films. Due to this fact, the antioxidants were extracted and identified by spectroscopic analysis; and they were also quantified using the Folin-Denis method and a gallic acid calibration curve, which confirmed the presence of natural antioxidants in the films. According to the SEM analysis, the presence of natural antioxidants has no influence on the film morphology because the stretch marks and white points that were observed were related to starch presence. On the other hand, the TGA analysis showed that the type of extract influences the total weight loss. The overall interpretation of the results suggests that the use of natural antioxidants as additives for chitosan-starch film preparation has a prominent impact on most of the critical properties that are decisive in making them suitable for food-packing applications.

Shear bond strength and enamel fracture behavior of ceramic brackets Fascination® and Fascination®2.

PubMed

Gittner, Robert; Müller-Hartwich, Ralf; Engel, Sylvia; Jost-Brinkmann, Paul-Georg

2012-01-01

The purpose of this study was to compare the shear bond strength and incidence of enamel fractures of the ceramic brackets Fascination® and Fascination®2. A total of 360 teeth (180 first upper bicuspids and 180 lower incisors) were stored in 96% ethanol, while 360 other teeth (180 first upper bicuspids and 180 lower incisors) were stored in 0.1% thymol. All 720 teeth were bonded one-half each with Fascination® and Fascination®2 brackets using three different adhesives and three different light curing units. The teeth were debonded with a debonding-device according to DIN EN ISO 10477 using a universal testing machine with a crosshead speed of 1 mm per minute. The enamel surface was then examined stereomicroscopically (10x and 40x magnification). The non-parametric Mann-Whitney U test was used, since the data were not normally distributed. The Fascination®2 brackets provided significantly lower shear bond strength than Fascination® brackets (p = 0.003). Fascination® brackets demonstrated significantly fewer, smaller enamel fractures than Fascination®2 brackets (p = 0.012). The lower shear bond strength of the Fascination®2 brackets is clinically acceptable, but our study's experimental design did not enable us to prove whether this is clinically associated with a lower risk of enamel fracture.

Effect of cytokinins on in vitro multiplication, volatiles composition and rosmarinic acid content of Thymus leucotrichus Hal. shoots.

PubMed

Bekircan, Tuba; Yaşar, Ahmet; Yıldırım, Sercan; Sökmen, Münevver; Sökmen, Atalay

2018-03-01

An efficient in vitro multiplication protocol was designed to Thymus leucotrichus , a subshrub and perennial herb growing naturally in the Northwest of Turkey. Of all basal media studied, Murashige and Skoog medium was found to be superior to the others, providing higher shoot formation and the maximum shoot length. Varying concentrations of cytokinins, i.e., 6-benzyladenine, thidiazuron, 2-isopentenyladenine and kinetin were supplemented in the nutrient media to observe their effects on shoot development and biomass. Rosmarinic acid content and volatile compositions of both naturally growing plants and in vitro multiplied plantlets were also evaluated. 6-benzyladenine (1.0 mg/L) and kinetin (0.5 mg/L) were found to be optimum for shoot number and shoot elongation, respectively. Thidiazuron (1.0 mg/L) was superior for biomass production. Rosmarinic acid content of in vitro multiplied plants was found to be higher than that of wild plants, reaching a maximum with 0.5 mg/L 2-isopentenyladenine, which yielded 10.15 mg/g dry weight. The highest thymol content was obtained with 1.0 mg/L kinetin (55.82%), while thidiazuron (0.1 mg/L) increased carvacrol production (12.53%). Overall, Murashige and Skoog medium supplemented with 1.0 mg/L kinetin was determined to be the most favorable medium studied.

Supercritical fluid extraction of oregano (Origanum vulgare) essentials oils: anti-inflammatory properties based on cytokine response on THP-1 macrophages.

PubMed

Ocaña-Fuentes, A; Arranz-Gutiérrez, E; Señorans, F J; Reglero, G

2010-06-01

Two fractions (S1 and S2) of an oregano (Origanum vulgare) extract obtained by supercritical fluid extraction have been used to test anti-inflammatory effects on activated human THP-1 cells. The main compounds present in the supercritical extract fractions of oregano were trans-sabinene hydrate, thymol and carvacrol. Fractions toxicity was assessed using the mitochondrial-respiration-dependent 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) reduction method for several concentrations during 24 and 48 h of incubation. Concentrations higher than 30 microg/mL of both supercritical S1 and S2 oregano fractions caused a reduction in cell viability in a dose-dependent manner. Oxidized-LDLs (oxLDLs) activated THP-1 macrophages were used as cellular model of atherogenesis and the release/secretion of cytokines (TNT-alpha, IL-1beta, IL-6 and IL-10) and their respective mRNA expressions were quantified both in presence or absence of supercritical oregano extracts. The results showed a decrease in pro-inflammatory TNF-alpha, IL-1beta and IL-6 cytokines synthesis, as well as an increase in the production of anti-inflammatory cytokine IL-10. These results may suggest an anti-inflammatory effect of oregano extracts and their compounds in a cellular model of atherosclerosis. Copyright 2010 Elsevier Ltd. All rights reserved.

Antiandrogenic properties of parabens and other phenolic containing small molecules in personal care products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Jiangang; Ahn, Ki Chang; Gee, Nancy A.

2007-06-15

To identify the androgenic potency of commonly used antimicrobials, an in vitro androgen receptor-mediated transcriptional activity assay was employed to evaluate the androgenic/antiandrogenic activity of parabens and selected other antimicrobials containing a phenolic moiety. This cell-based assay utilizes a stably transfected cell line that lacks critical steroid metabolizing enzymes and is formatted in a 96-well format. At a concentration of 10 {mu}M, methyl-, propyl- and butyl-4-hydroxybenzoate (parabens) inhibited testosterone (T)-induced transcriptional activity by 40%, 33% and 19%, respectively (P < 0.05), while 4-hydroxybenzoic acid, the major metabolite of parabens, had no effect on T-induced transcriptional activity. Triclosan inhibited transcriptional activitymore » induced by T by more than 92% at a concentration of 10 {mu}M, and 38.8% at a concentration of 1.0 {mu}M (P < 0.05). Thirty-four percent of T-induced transcriptional activity was inhibited by thymol at 10 {mu}M (P < 0.05). Cell proliferation and/or cytotoxicity were not observed in any of the treatments. None of the compounds appeared to be androgenic when tested individually without T. The data presented in this report demonstrate that some widely used antimicrobial compounds have antiandrogenic properties and warrant further investigation to fully understand their potential impact on human reproductive health.« less

Molecular characterisation of a bio-based active packaging containing Origanum vulgare L. essential oil using pyrolysis gas chromatography-mass spectrometry.

PubMed

Llana-Ruíz-Cabello, María; Pichardo, Silvia; Jiménez-Morillo, Nicasio T; Bermúdez, José M; Aucejo, Susana; González-Vila, Francisco J; Cameán, Ana M; González-Pérez, José A

2016-07-01

Environmental, economic and safety challenges motivate shift towards safer materials for food packaging. New bioactive packaging techniques, i.e. addition of essential plant oils (EOs), are gaining attention by creating barriers to protect products from spoilage. Analytical pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) was used to fingerprint a bioactive polylactic acid (PLA) with polybutylene succinate (PBS) (950 g kg(-1) :50 g kg(-1) ) film extruded with variable quantities (0, 20, 50 and 100 g kg(-1) ) of Origanum vulgare EO. Main PLA:PBS pyrolysis products were lactide enantiomers and monomer units from the major PLA fraction and succinic acid anhydride from the PBS fraction. Oregano EO pyrolysis released cymene, terpinene and thymol/carvacrol peaks as diagnostic peaks for EO. In fact, linear correlation coefficients better than 0.950R(2) value (P < 0.001) were found between the chromatographic area of the diagnostic peaks and the amount of oregano EO in the bioplastic. The pyrolytic behaviour of a bio-based active package polymer including EO is studied in detail. Identified diagnostic compounds provide a tool to monitor the quantity of EO incorporated into the PLA:PBS polymeric matrix. Analytical pyrolysis is proposed as a rapid technique for the identification and quantification of additives within bio-based plastic matrices. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Matrix Effect on the Spray Drying Nanoencapsulation of Lippia sidoides Essential Oil in Chitosan-Native Gum Blends.

PubMed

Paula, Haroldo C B; Oliveira, Erick F; Carneiro, Maria J M; de Paula, Regina C M

2017-03-01

Essential oils have many applications in the pharmaceutical, chemical, and food fields, however, their use is limited to the fact that they are very labile, requiring their a priori encapsulation, aiming to preserve their properties.This work reports on the preparation of chitosan-gum nanoparticles loaded with thymol containing Lippia sidoides essential oil, using exudates of Anacardium Occidentale (cashew gum), Sterculia striata (chichá gum), and Anadenanthera macrocarpa trees (angico gum). Nanoparticles were produced by spray drying an emulsion of L. sidoides essential oil and aqueous solution of gums with different chitosan : gum ratios. Samples were characterized by FTIR and UV/VIS spectroscopy, particle size, volume distribution, and zeta potential. The FTIR spectrum showed the main signals of chitosan and the gums. Data obtained revealed that the samples had sizes in the nano range, varying from 17 nm to 800 nm. The zeta potential varied from + 30 mV to - 40 mV. Nanoparticle loading values varied from 6.7 % to 15.6 %, with an average encapsulating efficiency of 62 %, where the samples with high ratios of cashew gum and chichá gum presented high oil loading values. The data revealed that both the chitosan : gum ratio and polysaccharide characteristics play major roles in nanoencapsulation processes. Georg Thieme Verlag KG Stuttgart · New York.

In vitro inhibition of the bovine viral diarrhoea virus by the essential oil of Ocimum basilicum (basil) and monoterpenes.

PubMed

Kubiça, Thaís F; Alves, Sydney H; Weiblen, Rudi; Lovato, Luciane T

2014-01-01

The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 μg mL(-1)) and 1,8-cineole (CC50 = 2996.10 μg mL(-1)) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle.

Repellent activity of essential oils: a review.

PubMed

Nerio, Luz Stella; Olivero-Verbel, Jesus; Stashenko, Elena

2010-01-01

Currently, the use of synthetic chemicals to control insects and arthropods raises several concerns related to environment and human health. An alternative is to use natural products that possess good efficacy and are environmentally friendly. Among those chemicals, essential oils from plants belonging to several species have been extensively tested to assess their repellent properties as a valuable natural resource. The essential oils whose repellent activities have been demonstrated, as well as the importance of the synergistic effects among their components are the main focus of this review. Essential oils are volatile mixtures of hydrocarbons with a diversity of functional groups, and their repellent activity has been linked to the presence of monoterpenes and sesquiterpenes. However, in some cases, these chemicals can work synergistically, improving their effectiveness. In addition, the use of other natural products in the mixture, such as vanillin, could increase the protection time, potentiating the repellent effect of some essential oils. Among the plant families with promising essential oils used as repellents, Cymbopogon spp., Ocimum spp. and Eucalyptus spp. are the most cited. Individual compounds present in these mixtures with high repellent activity include alpha-pinene, limonene, citronellol, citronellal, camphor and thymol. Finally, although from an economical point of view synthetic chemicals are still more frequently used as repellents than essential oils, these natural products have the potential to provide efficient, and safer repellents for humans and the environment.

Antifungal activity of essential oils from Iranian plants against fluconazole-resistant and fluconazole-susceptible Candida albicans

PubMed Central

Sharifzadeh, Aghil; Shokri, Hojjatollah

2016-01-01

Objective: The purpose of this study was to assay the antifungal activity of selected essential oils obtained from plants against both fluconazole (FLU)-resistant and FLU-susceptible C. albicans strains isolated from HIV positive patients with oropharyngeal candidiasis (OPC). Materials and Methods: The essential oils were obtained by hydrodistillation method from Myrtus communis (My. communis), Zingiber officinale roscoe (Z. officinale roscoe), Matricaria chamomilla (Ma. chamomilla), Trachyspermum ammi (T. ammi) and Origanum vulgare (O. vulgare). The susceptibility test was based on the M27-A2 methodology. The chemical compositions of the essential oils were obtained by gas chromatography- mass spectroscopy (GC-MS). Results: In GC-MS analysis, thymol (63.40%), linalool (42%), α-pinene (27.87%), α-pinene (22.10%), and zingiberene (31.79%) were found to be the major components of T. ammi, O. vulgare, My. communis, Ma. chamomilla and Z. officinale roscoe, respectively. The results showed that essential oils have different levels of antifungal activity. O. vulgare and T. ammi essential oils were found to be the most efficient (P<0.05). The main finding was that the susceptibilities of FLU-resistant C. albicans to essential oils were higher than those of the FLU-susceptible yeasts. Conclusion: Results of this study indicated that the oils from medicinal plants could be used as potential anti FLU-resistant C. albicans agents. PMID:27222835

Total phenolic content, radical scavenging properties, and essential oil composition of Origanum species from different populations.

PubMed

Dambolena, José S; Zunino, María P; Lucini, Enrique I; Olmedo, Rubén; Banchio, Erika; Bima, Paula J; Zygadlo, Julio A

2010-01-27

The aim of this work was to compare the antiradical activity, total phenol content (TPC), and essential oil composition of Origanum vulgare spp. virens, Origanum x applii, Origanum x majoricum, and O. vulgare spp. vulgare cultivated in Argentina in different localities. The experiment was conducted in the research station of La Consulta (INTA-Mendoza), the research station of Santa Lucia (INTA-San Juan), and Agronomy Faculty of National University of La Pampa, from 2007 to 2008. The composition of the essential oils of oregano populations was independent of cultivation conditions. In total, 39 compounds were identified in essential oils of oregano from Argentina by means of GC-MS. Thymol and trans-sabinene hydrate were the most prominent compounds, followed by gamma-terpinene, terpinen-4-ol, and alpha-terpinene. O. vulgare vulgare is the only Origanum studied which is rich in gamma-terpinene. Among tested oregano, O. x majoricum showed the highest essential oil content, 3.9 mg g(-1) dry matter. The plant extract of O. x majoricum had greater total phenol content values, 19.36 mg/g dry weight, than the rest of oregano studied. To find relationships among TPC, free radical scavenging activity (FRSA), and climate variables, canonical correlations were calculated. The results obtained allow us to conclude that 70% of the TPC and FRSA variability can be explained by the climate variables (R(2) = 0.70; p = 8.3 x 10(-6)), the temperature being the most important climatic variable.

Phytochemical, antioxidant and antibacterial properties of Melissa officinalis and Dracocephalum moldavica essential oils.

PubMed

Ehsani, Ali; Alizadeh, Omar; Hashemi, Mohammad; Afshari, Asma; Aminzare, Majid

2017-01-01

Aromatic plants are rich in essential oils with considerable antimicrobial properties. The aim of this study was to investigate chemical composition, antimicrobial activity and antioxidant properties of Melissa officinalis and Deracocephalum moldavica essential oils (EOs). The identification of chemical constituents of the EOs was carried out using gas chromato-graphy-mass spectrometry analysis and antimicrobial activity of the EOs was evaluated by disc diffusion assay as well as determination of minimal inhibitory concentration (MIC) and minimal bactericidal concentration against four important food-borne bacteria: Salmonella typhimorium, Escherichia coli, Listeria monocytogenes and Staphylococcus aureus . Antioxidant activity of the EOs was also determined by 2,2-diphenyl-1-picrylhydrazyl, 2,2-azinobis 3-ethylbenzo thiazoline-6-sulfonic acid and β-carotene bleaching tests. The major compounds of D. moldavica were geranial (28.52%), neral (21.21%), geraniol (19.60%), geranyl acetate (16.72%) and the major compounds of M. officinalis EO were citronellal (37.33%), thymol (11.96%), citral (10.10%) and β-caryophyllene (7.27%). The underlying results indicated strong antimicrobial effects of the oils against tested bacteria. Staphylococcus aureus with the lowest MIC value (0.12 mg mL -1 ) for both EOs was the most sensitive bacterium, although, antibacterial effect of M. officinalis EO was stronger than D. moldavica . In addition, the results of the antioxidant activity showed that both EOs had notable antioxidant properties. In conclusion, both EOs are appropriate alternatives as potential sources of natural preservative agents with the aim of being applied in food industries.

Influence of Environmental Factors on Essential Oil Variability in Origanum compactum Benth. Growing Wild in Morocco.

PubMed

Aboukhalid, Kaoutar; Al Faiz, Chaouki; Douaik, Ahmed; Bakha, Mohamed; Kursa, Karolina; Agacka-Mołdoch, Monika; Machon, Nathalie; Tomi, Félix; Lamiri, Abdeslam

2017-09-01

The present study aimed to evaluate the influence of environmental factors on essential oils (EOs) composition of Origanum compactum populations sampled all over the distribution area of the species in Morocco, and to determine the extent of the chemical profiles throughout the geographical distribution of the species. The chemical compositions were submitted to canonical correlation analysis and canonical discriminant analysis that indicated a significant relationship between oil components and some environmental factors. According to their chemical composition and edapho-climatic characteristics, two major groups of populations were differentiated. The first group was composed of samples growing in regions with humid climate, clayey, sandy, and alkaline soils. These samples showed high thymol, α-terpineol, linalool, and carvacryl methyl oxide content. The second group consisted of plants belonging to semi-arid climate, and growing at high altitudes and silty soils. These samples were characterized by high carvacrol, α-thujene, α-terpinene, and myrcene content. However, populations exposed to sub-humid climate, appeared less homogeneous and belong mainly either to the first or second group. A significant correlation between some edaphic factors (pH, K 2 O content, soil texture) and the EOs yield of O. compactum plants was evidenced. In spite of the correlation obtained for the oil composition with edapho-climatic factors and the variance explained by the environmental data set, the observed EO diversity might be also genetically determined. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Enhanced bactericidal effect of enterocin A in combination with thyme essential oils against L. monocytogenes and E. coli O157:H7.

PubMed

Ghrairi, Taoufik; Hani, Khaled

2015-04-01

The combined effects of enterocin A with Thymus vulgaris essential oils (EOs) against Listeria monocytogenes and Escherichia coli O157:H7 were investigated in vitro by enumeration of surviving populations of testing pathogens and minimal inhibitory concentration (MIC) determination. Enterocin A was purified to homogeneity by RP-HPLC from the culture fluid of Enterococcus strain and thyme EOs were extracted from local Thymus vulgaris plants. The major constituent of thyme EOs oils determined by GC-MS was thymol (78.4 %). Combination of enterocin A with thyme EOs showed an enhanced bactericidal effect against Listeria monocytogenes. Checkerboard assay and isobologram construction displayed a synergistic interaction between these compounds against Listeria (FIC index <0.5). Moreover, the MIC value of enterocin A has fallen fivefold (from 4.57 to 0.9 μg/ml), while the MIC of thyme EOs decreased threefold (from 3.6 to 1.2 μg/ml). Treatments with enterocin A alone did not affect the growth of the enteric pathogen E. coli O157:H7. However, the addition of thyme EOs and enterocin A yielded a synergistic antimicrobial effect against E. coli (MIC thyme EOs decrease from 2.2 to 0.71 μg/ml). This is the first report on the combined effect of enterocin A and thyme EOs against food pathogen bacteria. This combination could be useful in food bio-preservation.

Down-regulatory effect of Thymus vulgaris L. on growth and Tri4 gene expression in Fusarium oxysporum strains.

PubMed

Divband, Kolsum; Shokri, Hojjatollah; Khosravi, Ali Reza

2017-03-01

The aims of this study were to evaluate the efficacy of Thymus vulgaris (T. vulgaris) essential oil on the fungal growth and Tri4 gene expression in Fusarium oxysporum (F. oxysporum) strains. The oil was obtained by water-distillation using a Clevenger-type system. The chemical composition of the essential oil was obtained by gas chromatography- mass spectroscopy (GC-MS) and by retention indices. The antifungal activity was evaluated by broth microdilution assay. A quantitative real time RT-PCR (qRT-PCR) assay was also developed specific for F. oxysporum on the basis of trichothecene biosynthetic gene, Tri4, which allowed discrimination from F. oxysporum. Results showed thymol (32.67%) and p-cymene (16.68%) as the main components of T. vulgaris. Minimum inhibitory concentration (MIC) values varied from 5 to 20 μg/ml with T. vulgaris (mean: 10.50 μg/ml), while minimum fungicidal concentration (MFC) values ranged from 8 to 30 μg/ml with mean value of 16.20 μg/ml qRT-PCR results revealed a downregulation from 4.04 to 6.27 fold of Tri4 gene expression of the fungi exposed to T. vulgaris essential oil. The results suggest that T. vulgaris oil can be considered potential alternative natural fungicide to the synthetic chemicals that are currently used to prevent and control seed-borne diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rapid detection of ciprofloxacin effects on Fusarium graminearum and F. avenaceum cells in modulating environmental pH using a reactive, non-toxic food-dye indicator.

PubMed

Yuan, Xiakun; Goh, Yit Kheng; Low, Nicholas; Vujanovic, Vladimir

2011-09-01

The objective of the study was to assess the effect of ciprofloxacin antibiotic on the physiological or phenotypic characteristics of food-borne toxigenic Fusarium graminearum and F. avenaceum molds under in vitro conditions. In the presence of ciprofloxacin, Fusarium mycelia growth and morphology were altered based on the antibiotic concentration range used. Results showed that ciprofloxacin in concentrations ≥40μg/mL induced chlamydospore formation in Fusaria and as such, this antibiotic should be considered as an important abiotic stress factor and growth inhibitor. A novel method was investigated to correlate chlamydospore formation with the colour changes observed in FD&C Green Number 3, a common water soluble food dye. The antibiotic-treated F. graminearum and F. avenaceum isolates produced chamydospores, which in turn altered environmental pH with concomitant changes in the colour and intensity of the dye. The colour changes observed as a function of environmental pH were supported by instrumental methods (pH meter and spectroscopy), and a commercial pH indicator (thymol blue) results. In conclusion, we propose that FD&C Green Number 3 can be used as an accurate indicator for the rapid assessment of Fusarium molds when grown on ciprofloxacin antibiotic-containing substrate. Special emphasis should be given to an indirect risk assessment of antibiotic effects on toxic molds. Copyright © 2011 Elsevier B.V. All rights reserved.

Antimicrobial profile of essential oils extracted from wild versus cultivated Origanum ehrenberjii against enteric bacteria.

PubMed

Barbour, Elie K; Dankar, Samar K; Shaib, Houssam A; Kumosani, Taha; Azhar, Esam; Masaudi, Saad; Iyer, Archana; Harakeh, Steve

2014-10-15

The role of Origanum ehrenberjii against bacteria that cause enteric diseases is well known. Salmonella and Enterococcus cause high rates of enteric infections around the world. The aim of this study was to extract essential oils from cultivated and naturally growing O. ehrenberjii, compare the chemical profiles of the extracts and estimate their antimicrobial efficacy against enteric pathogens. Sixteen compounds were recovered consistently from essential oils extracted from O. ehrenberjii of wild and cultivated origin. The chemical profiles were determined using GC-MS. Safety of the essential oils was determined by observing mortality of chicks after intramuscular administration of the oils. The antimicrobial efficacy of the oils against the enteric pathogens was determined by the Kirby-Bauer Single Disk Diffusion assay. The levels of thymol, carvacrol, para cymene and γ-terpinene were significantly different in the two oils. A significant difference in in vitro antimicrobial activity of the two oils against Salmonella enterica serovar Typhimurium was observed. Intramuscular administration of the two oils in one day-old chicks resulted in significant differences in mortality of 60% vs. 5% (p < 0.05) for wild and cultivated herbs respectively, reflecting the higher safety of the cultivated herb due to the differences in the levels of certain active ingredients. The chemical profile of essential oil of wild vs. cultivated O. ehrenberjii differ significantly at compound level, suggesting the reason for their significant difference in efficacy against Salmonella enterica serovar Typhimurium, and also significant differences in the toxicity of the two oils.

The antimicrobial effect of oregano essential oil, nisin and their combination against Salmonella Enteritidis in minced sheep meat during refrigerated storage.

PubMed

Govaris, A; Solomakos, N; Pexara, A; Chatzopoulou, P S

2010-02-28

The antimicrobial effect of oregano essential oil (EO) at 0.6 or 0.9%, nisin at 500 or 1000 IU/g, and their combination against Salmonella Enteritidis was studied in minced sheep meat during storage at 4 degrees or 10 degrees C for 12 days. Sensory evaluation showed that the addition of oregano EO at 0.6 or 0.9% in minced sheep meat was organoleptically acceptable, and attribute scores were higher for the EO at 0.6 than 0.9%. According to compositional analysis of the oregano EO, the phenols carvacrol (80.15%) and thymol (4.82%) were the predominant components. Treatment of minced sheep meat with nisin at 500 or 1000 IU/g, proved insufficient to act against S. Enteritidis. The combination of the oregano EO at 0.6% with nisin at 500 IU/g showed stronger antimicrobial activity against S. Enteritidis than the oregano EO at 0.6% but lower than the combination with nisin at 1000 IU/g, which in turn was lower than that of the oregano EO at 0.9%. In its turn, oregano EO at 0.9% showed lower antimicrobial activity than its combinations with nisin at 500 or 1000 IU/g, which showed a bactericidal effect against the pathogen. The inhibition percentages of all treatments against S. Enteritidis at 10 degrees C were higher than those at 4 degrees C. (c) 2009 Elsevier B.V. All rights reserved.

Analysis of pesticide residues on museum objects repatriated to the Hupa tribe of California.

PubMed

Palmer, Peter T; Martin, Matthew; Wentworth, Gregory; Caldararo, Niccolo; Davis, Lee; Kane, Shawn; Hostler, David

2003-03-15

In the past, it was common practice for museum professionals and private collectors to apply a variety of pesticide agents to objects in their collections to preserve them from depredations by microorganisms, fungi, and other pests. The Native American Graves Repatriation and Protection Act allows federally recognized tribes to request that museums return objects taken from their ancestors. Given that poor records were kept on the treatment of individual objects, it is unknown whether specific objects are contaminated with these pesticide agents. Although chemical analysis represents the only reliable means to determine the types and levels of pesticides on these objects, surprisingly few publications document the extent of this contamination in museum collections. This paper reports on the determination of arsenic, mercury, and several organic pesticides on 17 objects that were recently repatriated to the Hupa tribe in northern California. Four samples were taken from each object: two for arsenic and mercury analysis via flame atomic absorption spectrophotometry and two for organic pesticide analysis via gas chromatography/mass spectrometry. Percent levels (wt/wt) of mercury were detected on many samples, and 0.001 to 0.183% (wt/wt) levels of p-dichlorobenzene, naphthalene, thymol, lindane, and/or DDT were detected on many of the samples. These results indicate that Hupa tribal members should not wear these objects in religious ceremonies, proper precautions should be followed when dealing with potentially contaminated objects, and that more serious consideration should be given to this issue at a national level.

Influence of oregano essential oil on traditional Argentinean cheese elaboration: Effect on lactic starter cultures.

PubMed

Marcial, Guillermo E; Gerez, Carla L; de Kairuz, Martha Nuñez; Araoz, Victoria Coll; Schuff, Carola; de Valdez, Graciela Font

The aim of this work is to study the oregano essential oil (OEO) composition from Northwestern Argentinean regions and to evaluate its effect on the lactic starter cultures. The oregano used, Origanum vulgare var hirtum, was obtained from Andalgalá, Catamarca. The essential oil presented high amounts of α-terpinene (10%), γ-terpinene (15.1%), terpinen-4-ol (15.5%) and thymol (13.0%) as the main components. No negative effect on growth or metabolic activity of lactic acid bacteria Streptococcus thermophilus CRL 728 and CRL 813, Lactobacillus delbrueckii subsp. bulgaricus CRL 656 and CRL 468, and Lactococcus lactis subsp. lactis CRL 597 up to the maximum concentration (200μg/g) assayed was observed. No differences in the organoleptic characteristics of semi-hard cheeses flavored with oregano essential oil (200μg/g) and homemade cheeses flavored with oregano leaves were found. With respect to the microbiological quality of the products, neither enterobacteria nor mold and yeast were detected during ripening in essential-oil flavored cheese compared to control cheese (enterobacteria 2×10 3 UFC/g) and cheese flavored with oregano leaves (mold/yeast 4×10 4 CFU/g). Our results showed that the use of oregano essential oil and lactic starter culture considerably improved cheese quality. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Electrochemical monitoring of native catalase activity in skin using skin covered oxygen electrode.

PubMed

Nocchi, Sarah; Björklund, Sebastian; Svensson, Birgitta; Engblom, Johan; Ruzgas, Tautgirdas

2017-07-15

A skin covered oxygen electrode, SCOE, was constructed with the aim to study the enzyme catalase, which is part of the biological antioxidative system present in skin. The electrode was exposed to different concentrations of H 2 O 2 and the amperometric current response was recorded. The observed current is due to H 2 O 2 penetration through the outermost skin barrier (referred to as the stratum corneum, SC) and subsequent catalytic generation of O 2 by catalase present in the underlying viable epidermis and dermis. By tape-stripping the outermost skin layers we demonstrate that SC is a considerable diffusion barrier for H 2 O 2 penetration. Our experiments also indicate that skin contains a substantial amount of catalase, which is sufficient to detoxify H 2 O 2 that reaches the viable epidermis after exposure of skin to high concentrations of peroxide (0.5-1mM H 2 O 2 ). Further, we demonstrate that the catalase activity is reduced at acidic pH, as compared with the activity at pH 7.4. Finally, experiments with often used penetration enhancer thymol shows that this compound interferes with the catalase reaction. Health aspect of this is briefly discussed. Summarizing, the results of this work show that the SCOE can be utilized to study a broad spectrum of issues involving the function of skin catalase in particular, and the native biological antioxidative system in skin in general. Copyright © 2017 Elsevier B.V. All rights reserved.

Ziziphora clinopodioides Essential Oil and Nisin as Potential Antimicrobial Agents against Escherichia coli O157:H7 in Doogh (Iranian Yoghurt Drink)

PubMed Central

Shahbazi, Yasser

2015-01-01

The aim of the present study was to evaluate the effects of Ziziphora clinopodioides essential oil (0.1 and 0.2%) and nisin (250 and 500 IU/mL) separately and in combination on survival of Escherichia coli O157:H7 inoculated in Doogh (Iranian yoghurt drink) during storage under refrigerated temperature (4 ± 1°C) for 9 days. Viability of Lactobacillus casei at different concentrations of Z. clinopodioides essential oil (0.1 and 0.2%) in Doogh was also examined. The major components were carvacrol (64.22%), thymol (19.22%), γ-terpinene (4.63%), and p-cymene (4.86%). There was no significant difference (p > 0.05) between samples treated with nisin and those of untreated samples. Samples treated with both concentrations of the essential oil (0.1 and 0.2%) showed populations of E. coli O157:H7 significantly (p < 0.05) lower than those of untreated samples. The essential oil of Z. clinopodioides in combination with nisin had a potential synergistic effect against E. coli O157:H7 in Doogh samples after 5 days. The count of L. casei was not inhibited by different concentrations of the Z. clinopodioides essential oil. It is concluded that the leaf essential oil of Z. clinopodioides in combination with nisin can be applied as alternative antimicrobial agents in Doogh to inhibit the growth of E. coli O157:H7. PMID:26783466

Targeting the Oxidative Stress Response System of Fungi with Redox-Potent Chemosensitizing Agents

PubMed Central

Kim, Jong H.; Chan, Kathleen L.; Faria, Natália C. G.; Martins, M. de L.; Campbell, Bruce C.

2012-01-01

The cellular antioxidant system is a target in the antifungal action of amphotericin B (AMB) and itraconazole (ITZ), in filamentous fungi. The sakAΔ mutant of Aspergillus fumigatus, a mitogen-activated protein kinase (MAPK) gene deletion mutant in the antioxidant system, was found to be more sensitive to AMB or ITZ than other A. fumigatus strains, a wild type and a mpkCΔ mutant (a MAPK gene deletion mutant in the polyalcohol sugar utilization system). Complete fungal kill (≥99.9%) by ITZ or AMB was also achieved by much lower dosages for the sakAΔ mutant than for the other strains. It appears msnA, an Aspergillus ortholog to Saccharomyces cerevisiae MSN2 (encoding a stress-responsive C2H2-type zinc-finger regulator) and sakA and/or mpkC (upstream MAPKs) are in the same stress response network under tert-butyl hydroperoxide (t-BuOOH)-, hydrogen peroxide (H2O2)- or AMB-triggered toxicity. Of note is that ITZ-sensitive yeast pathogens were also sensitive to t-BuOOH, showing a connection between ITZ sensitivity and antioxidant capacity of fungi. Enhanced antifungal activity of AMB or ITZ was achieved when these drugs were co-applied with redox-potent natural compounds, 2,3-dihydroxybenzaldehyde, thymol or salicylaldehyde, as chemosensitizing agents. We concluded that redox-potent compounds, which target the antioxidant system in fungi, possess a chemosensitizing capacity to enhance efficacy of conventional drugs. PMID:22438852

In vitro inhibition of the bovine viral diarrhoea virus by the essential oil of Ocimum basilicum (basil) and monoterpenes

PubMed Central

Kubiça, Thaís F.; Alves, Sydney H.; Weiblen, Rudi; Lovato, Luciane T.

2014-01-01

The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 μg mL−1) and 1,8-cineole (CC50 = 2996.10 μg mL−1) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle. PMID:24948933

Oviposition Deterrent and Larvicidal and Pupaecidal Activity of Seven Essential Oils and their Major Components against Culex quinquefasciatus Say (Diptera: Culicidae): Synergism–antagonism Effects

PubMed Central

Andrade-Ochoa, Sergio; Sánchez-Aldana, Daniela; Chacón-Vargas, Karla Fabiola; Rivera-Chavira, Blanca E.; Camacho, Alejandro D.; Nogueda-Torres, Benjamín

2018-01-01

The larvicidal activity of essential oils cinnamon (Cinnamomum verum J. Presl), Mexican lime (Citrus aurantifolia Swingle) cumin (Cuminum cyminum Linnaeus), clove (Syzygium aromaticum (L.) Merr. & L.M.Perry), laurel (Laurus nobilis Linnaeus), Mexican oregano (Lippia berlandieri Schauer) and anise (Pimpinella anisum Linnaeus)) and their major components are tested against larvae and pupae of Culex quinquefasciatus Say. Third instar larvae and pupae are used for determination of lethality and mortality. Essential oils with more than 90% mortality after a 30-min treatment are evaluated at different time intervals. Of the essential oils tested, anise and Mexican oregano are effective against larvae, with a median lethal concentration (LC50) of 4.7 and 6.5 µg/mL, respectively. Anise essential oil and t-anethole are effective against pupae, with LC50 values of 102 and 48.7 µg/mL, respectively. Oregano essential oil and carvacrol also have relevant activities. A kinetic analysis of the larvicidal activity, the oviposition deterrent effect and assays of the effects of the binary mixtures of chemical components are undertaken. Results show that anethole has synergistic effects with other constituents. This same effect is observed for carvacrol and thymol. Limonene shows antagonistic effect with β-pinene. The high larvicidal and pupaecidal activities of essential oils and its components demonstrate that they can be potential substitutes for chemical compounds used in mosquitoes control programs. PMID:29443951

Larvicidal and acetylcholinesterase inhibitory activities of apiaceae plant essential oils and their constituents against aedes albopictus and formulation development.

PubMed

Seo, Seon-Mi; Jung, Chan-Sik; Kang, Jaesoon; Lee, Hyo-Rim; Kim, Sung-Woong; Hyun, Jinho; Park, Il-Kwon

2015-11-18

This study evaluated the larvicidal activity of 12 Apiaceae plant essential oils and their components against the Asian tiger mosquito, Aedes albopictus, and the inhibition of acetylcholine esterase with their components. Of the 12 plant essential oils tested, ajowan (Trachyspermum ammi), caraway seed (Carum carvi), carrot seed (Daucus carota), celery (Apium graveolens), cumin (Cuminum cyminum), dill (Anethum graveolens), and parsley (Petroselinum sativum) resulted in >90% larval mortality when used at 0.1 mg/mL. Of the compounds identified, α-phellandrene, α-terpinene, p-cymene, (-)-limonene, (+)-limonene, γ-terpinene, cuminaldehyde, neral, (S)-+-carvone, trans-anethole, thymol, carvacrol, myristicin, apiol, and carotol resulted in >80% larval mortality when used at 0.1 mg/mL. Two days after treatment, 24.69, 3.64, and 12.43% of the original amounts of the celery, cumin, and parsley oils, respectively, remained in the water. Less than 50% of the original amounts of α-phellandrene, 1,8-cineole, terpinen-4-ol, cuminaldehyde, and trans-antheole were detected in the water at 2 days after treatment. Carvacrol, α-pinene, and β-pinene inhibited the activity of Ae. albopictus acetylcholinesterase with IC50 values of 0.057, 0.062, and 0.190 mg/mL, respectively. A spherical microemulsion of parsley essential oil-loaded poly(vinyl alcohol) (PVA) was prepared, and the larvicidal activity of this formulation was shown to be similar to that of parsley oil.

Optimized ultrasonic assisted extraction-dispersive liquid-liquid microextraction coupled with gas chromatography for determination of essential oil of Oliveria decumbens Vent.

PubMed

Sereshti, Hassan; Izadmanesh, Yahya; Samadi, Soheila

2011-07-22

Ultrasonic assisted extraction-dispersive liquid-liquid microextraction (UAE-DLLME) coupled with gas chromatography (GC) was applied for extraction and determination of essential oil constituents of the plant Oliveria decumbens Vent. Scanning electron microscopy (SEM) was used to see the effect of ultrasonic radiation on the extraction efficiency. By comparison with hydrodistillation, UAE-DLLME is fast, low cost, simple, efficient and consuming small amount of plant materials (∼1.0 g). The effects of various parameters such as temperature, ultrasonication time, volume of disperser and extraction solvents were investigated by a full factorial design to identify significant variables and their interactions. The results demonstrated that temperature and ultrasonication time had no considerable effect on the results. In the next step, a central composite design (CCD) was performed to obtain the optimum levels of significant parameters. The obtained optimal conditions were: 0.45 mL for disperser solvent (acetonitrile) and 94.84 μL for extraction solvent (chlorobenzene). The limits of detection (LODs), linear dynamic range and determination coefficients (R(2)) were 0.2-29 ng mL(-1), 1-2100 ng mL(-1) and 0.995-0.998, respectively. The main components of the essential oil were: thymol (47.06%), carvacrol (23.31%), gamma-terpinene (18.94%), p-cymene (8.71%), limonene (0.76%) and myristicin (0.63%). Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of test concentration in the ready biodegradability test for chemical substances: Improvement of OECD test guideline 301C.

PubMed

Nabeoka, Ryosuke; Taruki, Masanori; Kayashima, Takakazu; Yoshida, Tomohiko; Kameya, Takashi

2016-01-01

In Japan, understanding the environmental persistence of chemicals is very important for risk assessment, and ready biodegradability tests are mainly conducted according to the Organisation for Economic Co-operation and Development test guideline 301C. However, the highest test concentration specified in test guideline 301C, 100 mg/L, may cause microbial toxicity and incomplete biodegradation. The authors performed test guideline 301C tests at test concentrations of 30 mg/L for 13 substances that were readily biodegradable in ready biodegradability tests but not in test guideline 301C tests. Of the 5 substances with potential to cause microbial toxicity at 100 mg/L, the percentage of biodegradation of sodium dimethyldithiocarbamate, 4-chloro-3-cresol (CC), thymol (THY), and p-tert-butyl-α-methylbenzenepropionaldehyde measured by biochemical oxygen demand (BOD) increased in the test guideline 301C test at 30 mg/L, suggesting a reduction in toxicity effects. Furthermore, CC and THY met the criteria for ready biodegradability, which are more than 60% of biodegradation by BOD and a 10-d window. Of the 8 substances with a low potential for causing microbial toxicity at 100 mg/L, the percentage of biodegradation of only 2-(diethylamino)ethanol increased in the test guideline 301C test at 30 mg/L. Employing a lower test concentration in the standard test guideline 301C test will contribute to improvement of consistency between results of a test guideline 301C test and other ready biodegradability tests. © 2015 SETAC.

Repellency Effect of Essential Oils of some Native Plants and Synthetic Repellents against Human Flea, Pulex irritans (Siphonaptera: Pulicidae)

PubMed Central

Ghavami, Mohammad Bagher; Poorrastgoo, Fahimeh; Taghiloo, Behrooz; Mohammadi, Jamshid

2017-01-01

Background: Fleas are important vectors of human and animal disease, and control measures for protection against their bites and flea-borne diseases are necessary. Methods: The essential oils (EOs) of four native medicinal plants, Ziziphora tenuiore, Myrtus communis, Achillea wilhelmsii and Mentha piperita were isolated by hydrodistillation technique and analyzed by GC-MC. The repellent activity of EOs and synthetic compounds, DEET and permethrin, were assayed on human subjects against field collected fleas. The effective doses of 50% and 90% of EOs and synthetic compounds were estimated by probit analysis of dose and response regression line. Results: Analysis of EOs revealed about 19 major components. All oils were found to be more repellent (ED50 range= 208–955μg cm−2) than DEET and permethrin (ED50 range= 27–182 × 103μg cm−2). Thyme and myrtle oils showed high repellent activities and among the total detected terpenes, thymol (36.26%) and α-pinene (32.5%) were the major components of those oils respectively. Conclusion: Low repellent potency of DEET and permethrin against fleas might be related to flea olfactory system and further molecular and electrophysiological studies are required to conceive new ideas for the discovery and development of the next generation of repellents. Based on high repellent activity of thyme and myrtle essential oils against Pulex irritans further studies should be staged to develop their appropriate effective formulations. Likewise, field trials should be carried out to evaluate the operational feasibility and dermal toxicity over a long period. PMID:29026857

Monoterpene isolated from the essential oil of Trachyspermum ammi is cytotoxic to multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus strains.

PubMed

Hosseinkhani, Faride; Jabalameli, Fereshteh; Banar, Maryam; Abdellahi, Nafiseh; Taherikalani, Morovat; Leeuwen, Willem B van; Emaneini, Mohammad

2016-04-01

The aim of this study was to determine whether an herbal extract containing monoterpene exhibited activity against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa isolated from clinical infection samples. The essential oil of Trachyspermum ammi (L.) Sprague ex Turrill (Apiaceae) fruit was extracted by hydrodistillation. Fruit residues were treated with hydrochloric acid and re-hydrodistilled to obtain volatile compounds. Compounds in the distilled oil were identified using gas-chromatography (GC) and GC-mass spectrometry (MS). The antibiotic susceptibility of all bacterial isolates was analyzed using both the disc diffusion method and determination of the minimum inhibitory concentration (MIC). The sensitivity of antibiotic-resistant isolates to essential oil was also determined by using the disc diffusion method and MIC determination. Of 26 clinical isolates, 92% were multidrug-resistant (MDR). Aromatic monoterpenes (thymol, paracymene, and gamma-terpinene) were the major (90%) components of the oil. Growth of S. aureus strains was successfully inhibited by the oil, with an inhibitory zone diameter (IZD) between 30-60mm and MIC <0.02μL/mL. The oil had no antimicrobial activity against clinical isolates of P. aeruginosa; rather, it prevented pigment production in these isolates. This study revealed that the essential oil of Trachyspermum ammi, which contains monoterpene, has good antibacterial potency. Monoterpenes could thus be incorporated into antimicrobial ointment formulas in order to treat highly drug-resistant S. aureus infections. Our findings also underscore the utility of research on natural products in order to combat bacterial multidrug resistance.

Time-dependent antibacterial effects of Aloe vera and Zataria multiflora plant essential oils compared to calcium hydroxide in teeth infected with Enterococcus faecalis.

PubMed

Abbaszadegan, Abbas; Sahebi, Safoora; Gholami, Ahmad; Delroba, Alireza; Kiani, Amin; Iraji, Aida; Abbott, Paul Vincent

2016-02-01

In the present in vitro study, we investigated the time-related antimicrobial efficacy of Aloe vera and Zataria multiflora (Z. multiflora) plant essential oils compared to calcium hydroxide ([Ca[OH]2 ) to eliminate Enterococcus faecalis (E. faecalis) from root canals. A new strain of E. faecalis (Enterococcus spp. AGH04) was isolated from a previously root-filled tooth with persistent apical periodontitis. The 16S rRNA sequence was analyzed and deposited in GeneBank under accession number KF465681. A total of 108 extracted human single-rooted teeth were contaminated with this bacterial strain and treated with Aloe vera essential oil, Z. multiflora essential oil, and Ca(OH)2 for 1, 7, and 14 days. Gas chromatography-mass spectrometry (GC-MS) was used to determine the chemical composition of the oils. The percentage reduction from initial c.f.u./mL counts were calculated and analyzed. Carvacrol, thymol, and linalool were the main constituents of both essential oils. The c.f.u./mL count reductions significantly increased for all three medicaments when the contact time was extended. A statistically-significant difference was observed between the medicaments after 1 and 7 days, but there was no significant difference after 14 days. Both medicinal herbs showed equal antimicrobial efficiency against E. faecalis, comparable to Ca(OH)2 for the prolonged contact time of 14 days. © 2014 Wiley Publishing Asia Pty Ltd.

Effects of Formulation on Microbicide Potency and Mitigation of the Development of Bacterial Insusceptibility

PubMed Central

Cowley, Nicola L.; Forbes, Sarah; Amézquita, Alejandro; McClure, Peter; Humphreys, Gavin J.

2015-01-01

Risk assessments of the potential for microbicides to select for reduced bacterial susceptibility have been based largely on data generated through the exposure of bacteria to microbicides in aqueous solution. Since microbicides are normally formulated with multiple excipients, we have investigated the effect of formulation on antimicrobial activity and the induction of bacterial insusceptibility. We tested 8 species of bacteria (7 genera) before and after repeated exposure (14 passages), using a previously validated gradient plating system, for their susceptibilities to the microbicides benzalkonium chloride, benzisothiozolinone, chlorhexidine, didecyldimethyl ammonium chloride, DMDM-hydantoin, polyhexamethylene biguanide, thymol, and triclosan in aqueous solution (nonformulated) and in formulation with excipients often deployed in consumer products. Susceptibilities were also assessed following an additional 14 passages without microbicide to determine the stability of any susceptibility changes. MICs and minimum bactericidal concentrations (MBC) were on average 11-fold lower for formulated microbicides than for nonformulated microbicides. After exposure to the antimicrobial compounds, of 72 combinations of microbicide and bacterium there were 19 ≥4-fold (mean, 8-fold) increases in MIC for nonformulated and 8 ≥4-fold (mean, 2-fold) increases in MIC for formulated microbicides. Furthermore, there were 20 ≥4-fold increases in MBC (mean, 8-fold) for nonformulated and 10 ≥4-fold (mean, 2-fold) increases in MBC for formulated microbicides. Susceptibility decreases fully or partially reverted back to preexposure values for 49% of MICs and 72% of MBCs after further passage. In summary, formulated microbicides exhibited greater antibacterial potency than unformulated actives and susceptibility decreases after repeated exposure were lower in frequency and extent. PMID:26253662

Activity of essential oils and individual components against acetyl- and butyrylcholinesterase.

PubMed

Orhan, Ilkay; Kartal, Murat; Kan, Yüksel; Sener, Bilge

2008-01-01

We have tested acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of nineteen essential oils obtained from cultivated plants, namely one from Anethum graveolens L. (organic fertilizer), two from Foeniculum vulgare Mill. collected at fully-mature and flowering stages (organic fertilizer), two from Melissa officinalis L. (cultivated using organic and chemical fertilizers), two from Mentha piperita L. and M. spicata L. (organic fertilizer), two from Lavandula officinalis Chaix ex Villars (cultivated using organic and chemical fertilizers), two from Ocimum basilicum L. (green and purple-leaf varieties cultivated using only organic fertilizer), four from Origanum onites L., O. vulgare L., O. munitiflorum Hausskn., and O. majorana L. (cultivated using organic fertilizer), two from Salvia sclarea L. (organic and chemical fertilizers), one from S. officinalis L. (organic fertilizer), and one from Satureja cuneifolia Ten. (organic fertilizer) by a spectrophotometric method of Ellman using ELISA microplate-reader at 1 mg/ml concentration. In addition, a number of single components widely encountered in most of the essential oils [gamma-terpinene, 4-allyl anisole, (-)-carvone, dihydrocarvone, (-)-phencone, cuminyl alcohol, cumol, 4-isopropyl benzaldehyde, trans-anethole, camphene, iso-borneol, (-)-borneol, L-bornyl acetate, 2-decanol, 2-heptanol, methyl-heptanol, farnesol, nerol, iso-pulegol, 1,8-cineole, citral, citronellal, citronellol, geraniol, linalool, alpha-pinene, beta-pinene, piperitone, iso-menthone, menthofurane, linalyl oxide, linalyl ester, geranyl ester, carvacrol, thymol, menthol, vanilline, and eugenol] was also screened for the same activity in the same manner. Almost all of the essential oils showed a very high inhibitory activity (over 80%) against both enzymes, whereas the single components were not as active as the essential oils.

A randomized controlled trial evaluating antioxidant-essential oil gel as a treatment for gingivitis in orthodontic patients.

PubMed

Martin, Benjamin J; Campbell, Phillip M; Rees, Terry D; Buschang, Peter H

2016-05-01

To evaluate the treatment effect of an antioxidant-essential oil gel on orthodontic patients with generalized gingivitis. The gel contains the essential oils menthol and thymol and the antioxidants ferulic acid and phloretin. Thirty patients from the university's orthodontic clinic were screened for gingivitis and randomly allocated into treatment and placebo-control groups. Each patient was evaluated at three orthodontic treatment visits (T1, T2, and T3). A periodontal examination, including probing depth (PD), bleeding on probing (BOP), gingival index (GI), and plaque index (PI) was performed at each visit. Between T1 and T2, patients were instructed to apply a topical gel (active or placebo) to their gingiva twice daily after brushing. From T2 to T3, patients were instructed to discontinue use of the gel. The treatment group showed statistically significant (P < .05) reductions of BOP (-13.6 percentage points) and GI (-0.14) between T1 and T2, and significant increases in BOP (13.3 percentage points) and GI (0.14) between T2 and T3. Except for an increase in the GI between T2 and T3, the control group showed no significant changes in BOP or GI over time. The only other significant changes that occurred pertained to the treatment group, which showed significant increases in PD (0.08 mm) and PI (0.18) between T2 and T3. Application of a topical antioxidant-essential oil gel is an effective means of reducing inflammation in orthodontic patients with gingivitis.

Inhibitory effect of Zataria multiflora Boiss. essential oil, alone and in combination with monolaurin, on Listeria monocytogenes

PubMed Central

Raeisi, Mojtaba; Tajik, Hossein; Razavi Rohani, Seyed Mehdi; Tepe, Bektas; Kiani, Hossein; Khoshbakht, Rahem; Shirzad Aski, Hesamaddin; Tadrisi, Hamed

2016-01-01

Listeria monocytogenes is one of the major causes of infections in developing countries. In this study, chemical composition and anti-listerial effect of the essential oil of Zataria multiflora Boiss. alone and in combination with monolaurin were evaluated at different pH values (5, 6, and 7) and temperatures (5 ˚C and 30 ˚C). Chemical composition of Zataria multiflora Boiss. essential oil was evaluated by gas chromatography-mass spectrometry (GC-MS) analysis. Minimum inhibitory concentration (MIC) of the essential oil and monolaurin were determined using microbroth dilution method and the interactions of essential oil and monolaurin were determined by the evaluation of fractional inhibitory concentrations (FIC) index. Carvacrol (63.20%) and thymol (15.10%) were found as the main components of the essential oil. The MIC values of the oil and monolaurin at pH 7 and 30 ˚C were measured as 312.50 µg mL-1 and 125.00 µg mL-1, respectively. Combination of monolaurin and Z. multiflora essential oil were found to act synergistically (FIC index < 0.5) against L. monocytogenes under different pH and temperature conditions. Decrease in the pH and temperature values have increased the anti-listerial activity of monolaurin and the essential oil. The lowest MIC value of monolaurin and essential oil was observed at pH 5 and 5 ˚C. According to our results, the oil alone or in combination with monolaurin at low pH and temperature conditions showed a promising inhibitory effect on L. monocytogenes. PMID:27226881

Physiological and biochemical effects of botanical extract from Piper nigrum Linn (Piperaceae) against the dengue vector Aedes aegypti Liston (Diptera: Culicidae).

PubMed

Lija-Escaline, Jalasteen; Senthil-Nathan, Sengottayan; Thanigaivel, Annamalai; Pradeepa, Venkatraman; Vasantha-Srinivasan, Prabhakaran; Ponsankar, Athirstam; Edwin, Edward Sam; Selin-Rani, Selvaraj; Abdel-Megeed, Ahmed

2015-11-01

The leaves of Piper nigrum L. (Piperaceae) were evaluated for chemical constituents and mosquito larvicidal activity against the larvae of Aedes aegypti. GC and GC-MS analyses revealed that the crude extracts contain 16 compounds. Thymol (20.77%) and ç-elemene (10.42%) were identified as the major constituents followed by cyclohexene, 4-ethenyl-4-methyl-3-(1-methylethenyl)-1-(1 methylethyl)-, (3R-trans) (7.58%), 4,6-octadienoic acid, 2-acetyl-2-methyl-, ethyl ester (6.98), 2(3H)-furanone, 3,4-bis(1,3-benzodioxol-5-ylmethyl) dihydro-, (3R-trans) (6.95%), 1-naphthalenol, 1,2,3,4,4a,7,8,8a-octahydro-1,6-dimethyl-4-(1-methylethyl)-, [1R-(1à,4á,4aá,8aá)]-(Cedreanol) (5.30%), trans-2-undecen-1-ol (4.48%), phytol (4.22%), 1,6-cyclodecadiene, 1-methyl-5-methylene-8-(1-methylethyl)-,[s-(E,E)] (3.78%) and 2,6-dimethyl-3,5,7-octatriene-2-ol, Z,Z (2.39%). Larval mortality was observed after 3 h of exposure period. The crude extract showed remarkable larvicidal activity against Ae. aegypti (LC50 = 34.97). The larvae of Ae. aegypti exposed to the P. nigrum, significantly reduced the activities of α- and β-carboxylesterases and superdioxide. Further, P. nigrum extract was severely affecting the mosquito gut cellular organelles. Based on the results, the chemical constituents of crude extracts of P. nigrum can be considered as a new source of larvicide for the control of Ae. aegypti.

Development of LLDPE based active nanocomposite films with nanoclays impregnated with volatile compounds.

PubMed

Tornuk, Fatih; Sagdic, Osman; Hancer, Mehmet; Yetim, Hasan

2018-05-01

In this study, a novel procedure was performed for grafting of nanoclays (montmorillonite (MMT) and halloysite (HNT)) with essential oil constituents (thymol (THY), eugenol (EUG) and carvacrol (CRV)) using Tween 80 as surfactant and then the nanoclay particles were incorporated into LLDPE pellets (5 wt%) to produce active nanocomposite films using a twin screw extruder. The resulting nanocomposite films were analyzed for antimicrobial and antioxidant capacity as well as thickness, mechanical, color, barrier, thermal properties and surface morphology and molecular composition. Release of the active compounds from the films at the refrigerated and room temperature conditions were also tested. The results showed that the films had strong in vitro antibacterial activity against pathogenic bacteria (Salmonella Typhimurium, Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus) while their effect against lactic acid bacteria (Lactobacillus rhamnosus and Lb. casei) was limited. The lowest and highest DPPH scavenging ability levels were 65.59% and % 87.92, belonged to THY-MMT and EUG-MMT, respectively. Release of active compounds at 24 °C was much more rapid than at 4 °C. CRV-HNT and THY-HNT provided slower release than the other films. SEM results showed that nanoclays were uniformly dispersed in the polymer matrix with exceptional agglomerates. Incorporation of the active nanoclays significantly (P > 0.05) improved tensile strength and elongation of the films. The results confirmed that LLDPE based active nanocomposite films could be successfully produced due to its good interaction with MMT and HNT, activated with THY, EUG and CRV. Copyright © 2018 Elsevier Ltd. All rights reserved.

Essential oils of medicinal plants from the central andes of Argentina: chemical composition, and antifungal, antibacterial, and insect-repellent activities.

PubMed

Lima, Beatriz; López, Sandra; Luna, Lorena; Agüero, María B; Aragón, Liliana; Tapia, Alejandro; Zacchino, Susana; López, María L; Zygadlo, Julio; Feresin, Gabriela E

2011-05-01

The antifungal, antibacterial, and insect-repellent activities of the essential oils (EOs) of Acantholippia seriphioides, Artemisia mendozana, Gymnophyton polycephalum, Satureja parvifolia, Tagetes mendocina, and Lippia integrifolia, collected in the Central Andes area, province of San Juan, Argentina, were investigated. The dermatophytes Microsporum gypseum, Trichophyton mentagrophytes, and T. rubrum were inhibited by the EOs of G. polycephalum, L. integrifolia, and S. parvifolia, with minimum inhibitory concentrations (MICs) between 31.2 and 1000 μg/ml. Moreover, all EOs presented moderate activity against the bacteria tested, and the L. integrifolia and G. polycephalum EOs showed excellent repellent properties against Triatoma infestans, the Chagas disease vector, with repellency values between 60 and 100%. The A. seriphioides, G. polycephalum, and L. integrifolia EOs, obtained by hydrodistillation, were characterized by GC-FID and GC/MS analyses. The highest number of components (40) was identified in L. integrifolia EO, which, along with that of A. seriphioides, contained important amounts of oxygenated monoterpenes (44.35 and 29.72%, resp.). Thymol (27.61%) and carvacrol (13.24%) were the main components of A. seriphioides EO, and borneol, lippifoli-1(6)-en-5-one, and terpinen-4-ol (>8.5%) were the principal compounds of L. integrifolia EO. These results support the idea that oxygenated monoterpenes are the bioactive fractions of the EOs. Finally, the study shows that these Andean species might be used to treat superficial fungal infections and to improve the local Chagas disease situation by vector-control. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

Inhibitory effect of Zataria multiflora Boiss. essential oil, alone and in combination with monolaurin, on Listeria monocytogenes.

PubMed

Raeisi, Mojtaba; Tajik, Hossein; Razavi Rohani, Seyed Mehdi; Tepe, Bektas; Kiani, Hossein; Khoshbakht, Rahem; Shirzad Aski, Hesamaddin; Tadrisi, Hamed

2016-01-01

Listeria monocytogenes is one of the major causes of infections in developing countries. In this study, chemical composition and anti-listerial effect of the essential oil of Zataria multiflora Boiss. alone and in combination with monolaurin were evaluated at different pH values (5, 6, and 7) and temperatures (5 ˚C and 30 ˚C). Chemical composition of Zataria multiflora Boiss. essential oil was evaluated by gas chromatography-mass spectrometry (GC-MS) analysis. Minimum inhibitory concentration (MIC) of the essential oil and monolaurin were determined using microbroth dilution method and the interactions of essential oil and monolaurin were determined by the evaluation of fractional inhibitory concentrations (FIC) index. Carvacrol (63.20%) and thymol (15.10%) were found as the main components of the essential oil. The MIC values of the oil and monolaurin at pH 7 and 30 ˚C were measured as 312.50 µg mL(-1) and 125.00 µg mL(-1), respectively. Combination of monolaurin and Z. multiflora essential oil were found to act synergistically (FIC index < 0.5) against L. monocytogenes under different pH and temperature conditions. Decrease in the pH and temperature values have increased the anti-listerial activity of monolaurin and the essential oil. The lowest MIC value of monolaurin and essential oil was observed at pH 5 and 5 ˚C. According to our results, the oil alone or in combination with monolaurin at low pH and temperature conditions showed a promising inhibitory effect on L. monocytogenes.

Methodology for the Absolute Configuration Determination of Epoxythymols Using the Constituents of Ageratina glabrata.

PubMed

Arreaga-González, Héctor M; Pardo-Novoa, Julio C; Del Río, Rosa E; Rodríguez-García, Gabriela; Torres-Valencia, J Martín; Manríquez-Torres, J Jesús; Cerda-García-Rojas, Carlos M; Joseph-Nathan, Pedro; Gómez-Hurtado, Mario A

2018-01-26

A methodology to determine the enantiomeric excess and the absolute configuration (AC) of natural epoxythymols was developed and tested using five constituents of Ageratina glabrata. The methodology is based on enantiomeric purity determination employing 1,1'-bi-2-naphthol (BINOL) as a chiral solvating agent combined with vibrational circular dichroism (VCD) measurements and calculations. The conformational searching included an extensive Monte Carlo protocol that considered the rotational barriers to cover the whole conformational spaces. (+)-(8S)-10-Benzoyloxy-6-hydroxy-8,9-epoxythymol isobutyrate (1), (+)-(8S)-10-acetoxy-6-methoxy-8,9-epoxythymol isobutyrate (4), and (+)-(8S)-10-benzoyloxy-6-methoxy-8,9-epoxythymol isobutyrate (5) were isolated as enantiomerically pure constituents, while 10-isobutyryloxy-8,9-epoxythymol isobutyrate (2) was obtained as a 75:25 (8S)/(8R) scalemic mixture. In the case of 10-benzoyloxy-8,9-epoxythymol isobutyrate (3), the BINOL methodology revealed a 56:44 scalemic mixture and the VCD measurement was beyond the limit of sensitivity since the enantiomeric excess is only 12%. The racemization process of epoxythymol derivatives was studied using compound 1 and allowed the clarification of some stereochemical aspects of epoxythymol derivatives since their ACs have been scarcely analyzed and a particular behavior in their specific rotations was detected. In more than 30 oxygenated thymol derivatives, including some epoxythymols, the reported specific rotation values fluctuate from -1.6 to +1.4 passing through zero, suggesting the presence of scalemic and close to racemic mixtures, since enantiomerically pure natural constituents showed positive or negative specific rotations greater than 10 units.

The SOS Chromotest applied for screening plant antigenotoxic agents against ultraviolet radiation.

PubMed

Fuentes, J L; García Forero, A; Quintero Ruiz, N; Prada Medina, C A; Rey Castellanos, N; Franco Niño, D A; Contreras García, D A; Córdoba Campo, Y; Stashenko, E E

2017-09-13

In this work, we investigated the usefulness of the SOS Chromotest for screening plant antigenotoxic agents against ultraviolet radiation (UV). Fifty Colombian plant extracts obtained by supercritical fluid (CO 2 ) extraction, twelve plant extract constituents (apigenin, carvacrol, β-caryophyllene, 1,8-cineole, citral, p-cymene, geraniol, naringenin, pinocembrin, quercetin, squalene, and thymol) and five standard antioxidant and/or photoprotective agents (curcumin, epigallocatechin gallate, resveratrol, α-tocopherol, and Trolox®) were evaluated for their genotoxicity and antigenotoxicity against UV using the SOS Chromotest. None of the plant extracts, constituents or agents were genotoxic in the SOS Chromotest at tested concentrations. Based on the minimal extract concentration that significantly inhibited UV-genotoxicity (CIG), five plant extracts were antigenotoxic against UV as follows: Baccharis nítida (16 μg mL -1 ) = Solanum crotonifolium (16 μg mL -1 ) > Hyptis suaveolens (31 μg mL -1 ) = Persea caerulea (31 μg mL -1 ) > Lippia origanoides (62 μg mL -1 ). Based on CIG values, the flavonoid compounds showed the highest antigenotoxic potential as follows: apigenin (7 μM) > pinocembrin (15 μM) > quercetin (26 μM) > naringenin (38 μM) > epigallocatechin gallate (108 μM) > resveratrol (642 μM). UV-genotoxicity inhibition with epigallocatechin gallate, naringenin and resveratrol was related to its capability for inhibiting protein synthesis. A correlation analysis between compound antigenotoxicity estimates and antioxidant activity evaluated by the oxygen radical absorbance capacity (ORAC) assay showed that these activities were not related. The usefulness of the SOS Chromotest for bioprospecting of plant antigenotoxic agents against UV was discussed.

Evaluation of Antioxidant and Antibacterial Potentials of Nigella sativa L. Suspension Cultures under Elicitation.

PubMed

Chaudhry, Hera; Fatima, Nida; Ahmad, Iffat Zareen

2015-01-01

Nigella sativa L. (family Ranunculaceae) is an annual herb of immense medicinal properties because of its major active components (i.e., thymoquinone (TQ), thymohydroquinone (THQ), and thymol (THY)). Plant tissue culture techniques like elicitation, Agrobacterium mediated transformation, hairy root culture, and so on, are applied for substantial metabolite production. This study enumerates the antibacterial and antioxidant potentials of N. sativa epicotyl suspension cultures under biotic and abiotic elicitation along with concentration optimization of the elicitors for enhanced TQ and THY production. Cultures under different concentrations of pectin and manganese chloride (MnCl2) elicitation (i.e., 5 mg/L, 10 mg/L, and 15 mg/L) showed that the control, MnCl2 10 mg/L, and pectin 15 mg/L suspension extracts greatly inhibited the growth of E. coli, S. typhimurium, and S. aureus (MIC against E. coli, i.e., 2.35 ± 0.8, 2.4 ± 0.2, and 2.46 ± 0.5, resp.). Elicitation decreased SOD enzyme activity whereas CAT enzyme activity increased remarkably under MnCl2 elicitation. MnCl2 10 mg/L and pectin 15 mg/L elicitation enhanced the DPPH radical inhibition ability, but ferric scavenging activity was comparable to the control. TQ and THY were quantified by LC-MS/MS in the cultures with high bioactive properties revealing maximum content under MnCl2 10 mg/L elicitation. Therefore, MnCl2 elicitation can be undertaken on large scale for sustainable metabolite production.

Antimicrobial and seasonal evaluation of the carvacrol-chemotype oil from Lippia origanoides kunth.

PubMed

Sarrazin, Sandra Layse F; da Silva, Leomara Andrade; de Assunção, Ana Paula F; Oliveira, Ricardo B; Calao, Victor Y P; da Silva, Rodrigo; Stashenko, Elena E; Maia, José Guilherme S; Mourão, Rosa Helena V

2015-01-23

This study evaluated the influence of seasonal variation on the yield and composition of essential oil of Lippia origanoides occurring in the Middle Rio Amazonas, Brazil, and the impact on its antimicrobial potential. The average oil yield was 1.7% ± 0.2% in the rainy season and 1.6% ± 0.3% in the dry season. Some correlations with climatic parameters were observed. The major components were carvacrol (rainy, 43.5% ± 1.9%; dry, 41.4% ± 2.04%), thymol (rainy, 10.7% ± 1.1%; dry, 10.6% ± 0.9%), p-cymene (rainy, 9.8% ± 0.7%; dry, 10.0% ± 1.4%) and p-methoxythymol (rainy, 9.6% ± 0.8%; dry, 10.4% ± 1.4%). It was found that the antibacterial activity of L. origanoides against Staphylococcus aureus and Escherichia coli was little influenced by the changes in oil composition due to seasonal variation. Against S. aureus, the oil Minimum Inhibitory Concentration (MIC) value was 1.25 μL/mL over ten months. Against E. coli, the oil MIC values ranged from 0.15 μL/mL to 0.31 μL/mL in different months of the year. The Minimum Bactericidal Concentration (MBC) value was 2.5 μL/mL against S. aureus and 1.25 μL/mL against E. coli. The results suggest that the antimicrobial activity identified in the oil remain unchanged for the full year, allowing its medicinal use without any risk of loss or absence of the active principles of the plant.

Phytochemical, antioxidant and antibacterial properties of Melissa officinalis and Dracocephalum moldavica essential oils

PubMed Central

Ehsani, Ali; Alizadeh, Omar; Hashemi, Mohammad; Afshari, Asma; Aminzare, Majid

2017-01-01

Aromatic plants are rich in essential oils with considerable antimicrobial properties. The aim of this study was to investigate chemical composition, antimicrobial activity and antioxidant properties of Melissa officinalis and Deracocephalum moldavica essential oils (EOs). The identification of chemical constituents of the EOs was carried out using gas chromato-graphy-mass spectrometry analysis and antimicrobial activity of the EOs was evaluated by disc diffusion assay as well as determination of minimal inhibitory concentration (MIC) and minimal bactericidal concentration against four important food-borne bacteria: Salmonella typhimorium, Escherichia coli, Listeria monocytogenes and Staphylococcus aureus. Antioxidant activity of the EOs was also determined by 2,2-diphenyl-1-picrylhydrazyl, 2,2-azinobis 3-ethylbenzo thiazoline-6-sulfonic acid and β-carotene bleaching tests. The major compounds of D. moldavica were geranial (28.52%), neral (21.21%), geraniol (19.60%), geranyl acetate (16.72%) and the major compounds of M. officinalis EO were citronellal (37.33%), thymol (11.96%), citral (10.10%) and β-caryophyllene (7.27%). The underlying results indicated strong antimicrobial effects of the oils against tested bacteria. Staphylococcus aureus with the lowest MIC value (0.12 mg mL-1) for both EOs was the most sensitive bacterium, although, antibacterial effect of M. officinalis EO was stronger than D. moldavica. In addition, the results of the antioxidant activity showed that both EOs had notable antioxidant properties. In conclusion, both EOs are appropriate alternatives as potential sources of natural preservative agents with the aim of being applied in food industries. PMID:29085610

Sensitivity of human dental pulp cells to eighteen chemical agents used for endodontic treatments in dentistry.

PubMed

Kobayashi, Morio; Tsutsui, Takeo W; Kobayashi, Tomoko; Ohno, Maki; Higo, Yukari; Inaba, Tomohiro; Tsutsui, Takeki

2013-01-01

To determine the adverse effects against human dental pulp tissue, the sensitivity of human dental pulp cells (D824 cells) to 18 chemical agents used for endodontic treatments in dentistry was examined. The cytotoxicity, as determined by a decrease in colony-forming ability of cells treated with the chemical agents, increased as the concentration increased. As a quantitative measure of the cytotoxic effect, LC(50), the concentration which induces a 50% lethality, was extrapolated from the concentration-response curves. The rank of the chemical agents according to their cytotoxic effect (LC(50)) was sodium arsenite > formaldehyde > hydrogen peroxide > zinc oxide > thymol ≈ iodoform ≈ eugenol > guaiacol > ethylenediaminetetraacetic acid ≈ iodine > procaine > lidocaine ≈ chloramphenicol ≈ m-cresol > calcium hydroxide ≈ sodium hypochlorite ≈ phenol ≈ p-phenolsulfonic acid. To compare the cytotoxicity and the levels of apoptosis and mRNA expression of five genes related to the function of dental pulp tissue, D824 cells treated with the LC(50) concentrations of chemical agents were assayed by the TUNEL method and quantitative reverse transcription polymerase chain reaction analysis, respectively. The inducibility of apoptotic cells and the level of mRNA expression of the genes varied with the chemical agents, indicating that both effects occurred independent of the rank of cytotoxic effect of the chemical agents. The results not only provide information concerning cytotoxicity of various chemical agents to human dental pulp cells, but also show an insight into the diversity of the pharmacodynamic action of the chemical agents.

Evaluation of HS-SPME and ultrasonic solvent extraction for monitoring of plant flavours added by the bees to herbhoneys: traceability biomarkers.

PubMed

Kuś, Piotr Marek; Marijanović, Zvonimir; Jerković, Igor

2015-01-01

The volatile composition of 21 herbhoneys (HHs) of 7 different botanical origins was characterised for the first time. Ultrasound solvent extraction (USE) and headspace solid-phase microextraction (HS-SPME) followed by GC-FID/MS were successfully applied as complementary methods for monitoring the volatile plant flavours added by the bees. HHs showed significant compositional variability related to the botanical origin and compounds that could serve as traceability biomarkers were identified. The most important compounds with high abundance were (E,extract; H, headspace): caffeine (up to 68.7%, E) and trans-linalool oxide (up to 26.0%, H) in coffee HH, α-terpineol (up to 8.2%, E; 27.1%, H) and bornyl acetate (up to 3.1, E; 11.9%, H) in pine HH, thymol (up to 3.1%, E; 55.4%, H) in thyme HH. Hawthorn HH was characterised by the presence of herniarin (up to 13.4%, E) and lemon HH contained limonene (up to 1.6%, E; 33.2%, H). Other HHs (nettle and aloe) contained lower amounts of volatiles and their profiles were not specific. In all the HHs, methyl syringate was found and it was most abundant in thyme HH (up to 17.4%, E). The volatile fraction of HHs showed some substantial similarities and differences with the composition of herbs from which they derive. It confirms the selective bee-mediated transfer of phytochemicals, including known flavour-active volatiles into the final product, but also biotransformation of several compounds. Additionally, several similarities to the corresponding natural honeys were observed, but in general HHs exhibited less rich volatile profiles.

Reversal of efflux mediated antifungal resistance underlies synergistic activity of two monoterpenes with fluconazole.

PubMed

Ahmad, Aijaz; Khan, Amber; Manzoor, Nikhat

2013-01-23

Thymol (THY) and carvacrol (CARV), the principal chemical components of thyme oil have long been known for their wide use in medicine due to antimicrobial and disinfectant properties. This study, however, draws attention to a possible synergistic antifungal effect of these monoterpenes with azole antimycotic-fluconazole. Resistance to azoles in Candida albicans involves over-expression of efflux-pump genes MDR1, CDR1, CDR2 or mutations and over-expression of target gene ERG11. The inhibition of drug efflux pumps is considered a feasible strategy to overcome clinical antifungal resistance. To put forward this approach, we investigated the combination effects of these monoterpenes and FLC against 38 clinically obtained FLC-sensitive, and eleven FLC-resistant Candida isolates. Synergism was observed with combinations of THY-FLC and CARV-FLC evaluated by checkerboard microdilution method and nature of the interactions was calculated by FICI. In addition, antifungal activity was assessed using agar-diffusion and time-kill curves. The drug efflux activity was determined using two dyes, Rhodamine6G (R6G) and fluorescent Hoechst 33342. No significant differences were observed in dye uptakes between FLC-susceptible and resistant isolates, incubated in glucose free buffer. However, a significantly higher efflux was recorded in FLC-resistant isolates when glucose was added. Both monoterpenes inhibited efflux by 70-90%, showing their high potency to block drug transporter pumps. Significant differences, in the expression levels of CDR1 and MDR1, induced by monoterpenes revealed reversal of FLC-resistance. The selectively fungicidal characteristics and ability to restore FLC susceptibility in resistant isolates signify a promising candidature of THY and CARV as antifungal agents in combinational treatments for candidiasis. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of an essential oil-containing dentifrice on dental plaque microbial composition.

PubMed

Charles, C H; Vincent, J W; Borycheski, L; Amatnieks, Y; Sarina, M; Qaqish, J; Proskin, H M

2000-09-01

To determine the effect of 6 months use of an essential oil-containing (EO) antiplaque/antigingivitis fluoride dentifrice on the balance of the oral microbial flora and on the emergence of resistant microbial forms by analysis of dental plaque and saliva. The dentifrice essential oils consisted of a fixed combination of thymol, menthol, methyl salicylate, and eucalyptol. An identical fluoride-containing dentifrice without the essential oils served as the control. A subgroup of 66 subjects from a clinical trial population of 321 was randomly selected for characterization of their dental plaque microflora. Saliva was also cultured to monitor for the emergence of opportunistic pathogens. Supragingival plaque and saliva were harvested at baseline, after which subjects received a dental prophylaxis. Subjects were sampled again after 3 and 6 months of product use prior to clinical examination. Plaque was characterized for microbial content by phase contrast microscopy for recognizable cellular morphotypes and by cultivation on nonselective and selective culture media. Determination of the minimum inhibitory concentrations of the test agent against selected Actinomyces and Veillonella isolated bacterial species was conducted at all time points to monitor for the potential development of bacterial resistance. There were no statistically significant differences between the microbial flora obtained from subjects using the essential oil-containing dentifrice and the vehicle control for all parameters and time periods except for the percentage of spirochetes at 6 months and for percentage of "other" microorganisms at 3 months. The EO group exhibited a lower adjusted mean for both parameters. Additionally, there was no evidence of the development of bacterial resistance to the antimicrobial activity of the essential oils or the emergence of opportunistic pathogens.

Detoxification of Hg(II) from aqueous and enzyme media: Pristine vs. tailored calcium alginate hydrogels.

PubMed

Sarkar, Kangkana; Ansari, Zarina; Sen, Kamalika

2016-10-01

Calcium alginate (CA) hydrogels were tailored using phenolic compounds (PC) like, thymol, morin, catechin, hesperidin, during their preparation. The PC incorporated gels show modified surface features as indicated by scanning electron microscopic images (SEM). The rheological studies show that excepting the hesperidin incorporated gels all the other kinds including calcium alginate pristine have similar mechanical strength. The hesperidine incorporated CA gels had the maximum capacity to adsorb Hg. The Freundlich adsorption isotherms show higher values of adsorption capacity for all PC incorporated CA beads than the pristine CA (PCA). The hesperidin incorporated CA gels were found to show the best adsorption condition at neutral pH and an optimum contact time of 2.5h at 25°C. Considering the possibility of ingested Hg detoxification from human alimentary tract, the hesperidin and morin incorporated CA beads were further modified through incorporation of cod liver oil as the digestion time of fat in stomach is higher. In vitro uptake capacities of Hg in pepsin and pancreatin containing enzyme media were studied with hesperidin and morin incorporated beads and their corresponding fat incorporated beads also. In the pepsin medium, there was no uptake by hesperidin and fat-hesperidin incorporated beads, which is possibly due to the higher acidity of the medium. But in pancreatin medium Hg was taken up by both kinds of beads. Morin and morin-fat incorporated beads were efficient to uptake Hg from both the pepsin and pancreatin medium. The tailored CA beads may therefore serve as efficient scaffolds to rescue Hg ingested individuals. Copyright © 2016 Elsevier B.V. All rights reserved.

Efficacy of Nanoencapsulated Thymus eriocalyx and Thymus kotschyanus Essential Oils by a Mesoporous Material MCM-41 Against Tetranychus urticae (Acari: Tetranychidae).

PubMed

Ebadollahi, Asgar; Sendi, Jalal Jalali; Aliakbar, Alireza

2017-12-05

Inspite of well-established potentiality of plant essential oils as biopesticides, their environmentally low persistence is considered as a hindering obstacle for its commercialization. In the present study, chemical composition and toxicity of essential oils isolated from leaves of Thymus eriocalyx and Thymus kotschyanus were evaluated against two-spotted spider mite, Tetranychus urticae. The chemicals present in the crude oil were found to be thymol (28.83%), oleic acid (11.51%), palmitic acid (8.60%), borneol (5.72%), ρ-cymene (3.60%), and 1,8-cineole (3.57%) in the essential oil of T. eriocalyx, and camphene (35.59%), linalyl acetate (20.47%), linalool (14.75%), α-terpineol (13.87%), and geranyl acetate (3.07%) in the essential oil of T. kotschyanus. The essential oils had strong fumigant toxicity on the adult females of Te. urticae and their fumigation persistence was prolonged until 6 and 5 d, respectively, for T. eriocalyx and T. kotschyanus. Loading of essential oils in MCM-41 increased their stability and persistence was extended up to 20 and 18 d for T. eriocalyx and T. kotschyanus. Further, mite mortality increased from 80 to 203 mites by T. eriocalyx and from 58 to 186 mites by T. kotschyanus nanoencapsulated essential oils. Based on these results, nanoencapsulation of T. eriocalyx and T. kotschyanus essential oils in MCM-41 may be a useful method for their application in the management of Te. urticae. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Carbonic anhydrase activity in Arabidopsis thaliana thylakoid membrane and fragments enriched with PSI or PSII.

PubMed

Ignatova, Lyudmila K; Rudenko, Natalia N; Mudrik, Vilen A; Fedorchuk, Tat'yana P; Ivanov, Boris N

2011-12-01

The procedure of isolating the thylakoids and the thylakoid membrane fragments enriched with either photosystem I or photosystem II (PSI- and PSII-membranes) from Arabidopsis thaliana leaves was developed. It differed from the one used with pea and spinach in durations of detergent treatment and centrifugation, and in concentrations of detergent and Mg(2+) in the media. Both the thylakoid and the fragments preserved carbonic anhydrase (CA) activities. Using nondenaturing electrophoresis followed by detection of CA activity in the gel stained with bromo thymol blue, one low molecular mass carrier of CA activity was found in the PSI-membranes, and two carriers, a low molecular mass one and a high molecular mass one, were found in the PSII-membranes. The proteins in the PSII-membranes differed in their sensitivity to acetazolamide (AA), a specific CA inhibitor. AA at 5 × 10(-7) M inhibited the CA activity of the high molecular mass protein but stimulated the activity of the low molecular mass carrier in the PSII-membranes. At the same concentration, AA moderately inhibited, by 30%, the CA activity of PSI-membranes. CA activity of the PSII-membranes was almost completely suppressed by the lipophilic CA inhibitor, ethoxyzolamide at 10(-9) M, whereas CA activity of the PSI-membranes was inhibited by this inhibitor even at 5 × 10(-7) M just the same as for AA. The observed distribution of CA activity in the thylakoid membranes from A. thaliana was close to the one found in the membranes of pea, evidencing the general pattern of CA activity in the thylakoid membranes of C3-plants. © Springer Science+Business Media B.V. 2011

Antimicrobial activity of Satureja montana L. essential oil against Clostridium perfringens type A inoculated in mortadella-type sausages formulated with different levels of sodium nitrite.

PubMed

de Oliveira, Thales Leandro Coutinho; de Araújo Soares, Rodrigo; Ramos, Eduardo Mendes; das Graças Cardoso, Maria; Alves, Eduardo; Piccoli, Roberta Hilsdorf

2011-01-05

This research evaluated the antimicrobial effect of the winter savory (Satureja montana L.) essential oil (EO) against Clostridium perfringens type A (ATCC 3624) inoculated in mortadella-type sausages formulated with different levels of sodium nitrite (NaNO₂: 0 ppm, 100 ppm and 200 ppm) in addition to EO at concentrations of 0.0%, 0.78%, 1.56% and 3.125% stored at 25°C for 30 days. The EO extracted by hydrodistillation and analyzed by gas chromatography-mass spectrometry (CG-MS) was tested in vitro using an agar well diffusion method for determination of minimum inhibitory concentration (MIC) on C. perfringens. According to compositional analysis of the winter savory EO, 26 chemical compounds were identified, and the major constituents were thymol (28.99%), p-cymene (12.00%), linalool (11.00%) and carvacrol (10.71%). The results obtained showed that EO applied at a concentration of 1.56%, which was defined as the MIC, exhibited antimicrobial activity against C. perfringens in the in vitro assays, and the transmission electron microscopy (TEM) revealed structural damage and cell lysis of C. perfringens caused by EO treatment. A synergistic effect between NaNO₂ and EO was observed. In mortadella-type sausages formulated with 100 ppm of NaNO₂ and EO at all concentrations tested, the population of target microorganisms was reduced (p≤0.05) compared to control samples during all storage period. This data suggests the potential combined use of savory EO and minimal amounts of the synthetic additive, NaNO₂ to control C. perfringens in mortadella, which goes according to current market trends, where consumers are requesting natural products. Copyright © 2010 Elsevier B.V. All rights reserved.

Novel polymeric micelles for insect pest control: encapsulation of essential oil monoterpenes inside a triblock copolymer shell for head lice control.

PubMed

Lucia, Alejandro; Toloza, Ariel Ceferino; Guzmán, Eduardo; Ortega, Francisco; Rubio, Ramón G

2017-01-01

Essential oil components (EOCs) are molecules with interesting application in pest control, these have been evaluated against different insect pest from more than 100 years, but their practical use is rather limited. Thus, the enhancement of their bioavailability and manageability due to their dispersion in water can open new perspective for the preparation of formulations for the control of insect pest. In this work, we studied the encapsulation of different monoterpenes in a poloxamer shell in order to prepare aqueous formulations that can be used for the development of platforms used in pest control. Micellar systems containing a 5 wt% of poloxamer 407 and 1.25 wt% of the different monoterpenes were prepared. Dynamic Light Scattering (DLS) experiments were carried out to characterize the dispersion of the EOCs in water. The pediculicidal activity of these micellar systems was tested on head lice using an ex vivo immersion test. The poloxamers allowed the dispersion of EOCs in water due to their encapsulation inside the hydrophobic core of the copolymer micelles. From this study, we concluded that it is possible to make stable micellar systems containing water (>90 wt%), 1.25 wt% of different monoterpenes and a highly safe polymer (5wt% Poloxamer 407). These formulations were effective against head lice with mortality ranging from 30 to 60%, being the most effective emulsions those containing linalool, 1,8-cineole, α -terpineol, thymol, eugenol, geraniol and nonyl alcohol which lead to mortalities above 50%. Since these systems showed good pediculicidal activity and high physicochemical stability, they could be a new route for the green fabrication of biocompatible and biosustainable insecticide formulations.

In vivo and in vitro control activity of plant essential oils against three strains of Aspergillus niger.

PubMed

Kumar, Peeyush; Mishra, Sapna; Kumar, Atul; Kumar, Sanjeev; Prasad, Chandra Shekhar

2017-09-01

Contamination of environment and food from the prevalent spores and mycotoxins of Aspergillus niger has led to several diseases in humans and other animals. The present study investigated the control activity of plant essential oils against three strains of A. niger. In the elaborate assays done through microdilution plate assay and agar disk diffusion assay in the lab condition and in vivo assay on the stored wheat grains, the essential oil of Thymus vulgaris depicted overall superior efficacy. In microdilution plate assay, the oil of Anethum graveolens showed best fungistatic activity, while best fungicidal activity was depicted by Syzygium aromaticum oil. The oil of T. vulgaris showed moderate control efficacy against A. niger strains with its antifungal activity resulting mainly due to killing of microorganism rather than growth inhibition. In agar disk diffusion assay, T. vulgaris oil with a zone of inhibition (ZOI) of 23.3-61.1% was the most effective fungicide. The in vivo assay to evaluate the protection efficacy of oils for stored wheat grains against A. niger (AN1) revealed T. vulgaris (90.5-100%) to be the best control agent, followed by the oil of S. aromaticum (61.9-100%). The GC-MS analysis of T. vulgaris oil indicated the presence of thymol (39.11%), γ-terpinene (19.73%), o-cymene (17.21%), and β-pinene (5.38%) as major oil components. Phytotoxic effects of the oils on wheat seeds showed no significant phytotoxic effect of oils in terms of seed germination or seedling growth. The results of the study demonstrated control potentiality of essential oils for the protection of stored wheat against A. niger with prospect for development of eco-friendly antifungal products.

Antioxidant and biocidal activities of Carum nigrum (seed) essential oil, oleoresin, and their selected components.

PubMed

Singh, Gurdip; Marimuthu, Palanisamy; de Heluani, Carola S; Catalan, Cesar A N

2006-01-11

In the present study, chemical constituents of the essential oil and oleoresin of the seed from Carum nigrum obtained by hydrodistillation and Soxhlet extraction using acetone, respectively, have been studied by GC and GC-MS techniques. The major component was dillapiole (29.9%) followed by germacrene B (21.4%), beta-caryophyllene (7.8%), beta-selinene (7.1%), and nothoapiole (5.8%) along with many other components in minor amounts. Seventeen components were identified in the oleoresin (Table 2) with dillapiole as a major component (30.7%). It also contains thymol (19.1%), nothoapiole (15.2.3%), and gamma-elemene (8.0%). The antioxidant activity of both the essential oil and oleoresin was evaluated in mustard oil by monitoring peroxide, thiobarbituric acid, and total carbonyl and p-anisidine values of the oil substrate. The results showed that both the essential oil and oleoresin were able to reduce the oxidation rate of the mustard oil in the accelerated condition at 60 degrees C in comparison with synthetic antioxidants such as butylated hydroxyanisole and butylated hydroxytoluene at 0.02%. In addition, individual antioxidant assays such as linoleic acid assay, DPPH scavenging activity, reducing power, hydroxyl radical scavenging, and chelating effects have been used. The C. nigrum seed essential oil exhibited complete inhibition against Bacillus cereus and Pseudomonas aeruginosa at 2000 and 3000 ppm, respectively, by agar well diffusion method. Antifungal activity was determined against a panel of foodborne fungi such as Aspergillus niger, Penicillium purpurogenum, Penicillium madriti, Acrophialophora fusispora, Penicillium viridicatum, and Aspergillus flavus. The fruit essential oil showed 100% mycelial zone inhibition against P. purpurogenum and A. fusispora at 3000 ppm in the poison food method. Hence, both oil and oleoresin could be used as an additive in food and pharmaceutical preparations after screening.

Antiseptic mouth rinses: an update on comparative effectiveness, risks and recommendations.

PubMed

Osso, Diane; Kanani, Nehal

2013-02-01

Antiseptic mouth rinses are widely recommended and marketed to improve oral health. This article summarizes current studies on the comparative effectiveness of selected antiseptic mouth rinses in controlling plaque and gingivitis, as well as risks associated with daily exposure, including salivary flow rate, oral cancer and wear of composite restorations. Electronic database searches were conducted using Google Scholar and PubMed to identify articles comparing the effectiveness of 4 commercially marketed antiseptic mouth rinses differing in active ingredients (0.12% chlorhexidine gluconate, essential oils (menthol, thymol and eucalyptol) and methyl salicylate, 0.7% cetylpyridinium chloride and 20% aloe vera gel) for controlling plaque and gingivitis. Criteria for inclusion included controlled clinical trials and systematic reviews appearing in English language publications evaluating the comparative effectiveness of the mouth rinses in controlling plaque and gingivitis, as well as risks associated with daily usage. The majority of studies have shown mouth rinses containing chlorhexidine gluconate or essential oils and methyl salicylate provide clinically significant anti-gingivitis and anti-plaque benefits. Cetylpyridinium chloride has been found to provide only limited clinical benefits compared to inactive control mouth rinse. Inadequate evidence is available to evaluate the clinical effectiveness of aloe vera gel. Chlorhexidine, essential oils and cetylpyridinium have been found to be safe. However, limited data are available on the effects of the mouth rinse on wear patterns of dental restorations. Studies reviewed reported no significant difference in salivary flow rate related to alcohol based mouth rinse. Research supports the effectiveness of antiseptic mouth rinses in reducing plaque and gingivitis as an adjunct to home care. Insufficient evidence is available to support the claim that oral antiseptics can reduce the risk of developing periodontitis or the rate of progression of periodontitis.

In vitro activity of origanum vulgare essential oil against candida species

PubMed Central

Cleff, Marlete Brum; Meinerz, Ana Raquel; Xavier, Melissa; Schuch, Luiz Filipe; Schuch, Luiz Filipe; Araújo Meireles, Mário Carlos; Alves Rodrigues, Maria Regina; de Mello, João Roberto Braga

2010-01-01

The aim of this study was to evaluate the in vitro activity of the essential oil extracted from Origanum vulgare against sixteen Candida species isolates. Standard strains tested comprised C. albicans (ATCC strains 44858, 4053, 18804 and 3691), C. parapsilosis (ATCC 22019), C. krusei (ATCC 34135), C. lusitaniae (ATCC 34449) and C. dubliniensis (ATCC MY646). Six Candida albicans isolates from the vaginal mucous membrane of female dogs, one isolate from the cutaneous tegument of a dog and one isolate of a capuchin monkey were tested in parallel. A broth microdilution technique (CLSI) was used, and the inoculum concentration was adjusted to 5 x 106 CFU mL-1. The essential oil was obtained by hydrodistillation in a Clevenger apparatus and analyzed by gas chromatography. Susceptibility was expressed as Minimal Inhibitory Concentration (MIC) and Minimal Fungicidal Concentration (MFC). All isolates tested in vitro were sensitive to O. vulgare essential oil. The chromatographic analysis revealed that the main compounds present in the essential oil were 4-terpineol (47.95%), carvacrol (9.42%), thymol (8.42%) and □-terpineol (7.57%). C. albicans isolates obtained from animal mucous membranes exhibited MIC and MFC values of 2.72 μL mL-1 and 5 μL mL-1, respectively. MIC and MFC values for C. albicans standard strains were 2.97 μL mL-1 and 3.54 μL mL-1, respectively. The MIC and MFC for non-albicans species were 2.10 μL mL-1 and 2.97 μL mL-1, respectively. The antifungal activity of O. vulgare essential oil against Candida spp. observed in vitro suggests its administration may represent an alternative treatment for candidiasis. PMID:24031471

In vivo study of the efficacy of the aromatic water of Zataria multiflora on hydatid cysts.

PubMed

Moazeni, Mohammad; Larki, Sara; Saharkhiz, Mohammad Jamal; Oryan, Ahmad; Ansary Lari, Maryam; Mootabi Alavi, Amir

2014-10-01

Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were employed to determine the chemical composition of the essential oil (EO) from aromatic water (AW) of Zataria multiflora. Thymol (66.9%), carvacrol (15.2%), and carvone (7.3%) were found to be the major EO constituents. Eighty laboratory BALB/c mice were infected intraperitoneally by injection of 1,500 viable protoscolices and were divided into prevention (40 mice) and therapeutic (40 mice) groups. To prove the preventive effect of the Z. multiflora AW on development of hydatid cysts, the 40 infected mice were allocated into three treatment groups, including the albendazole group (10 mice that received 150 mg/kg body weight/day for 10 days), the Z. multiflora AW group (15 mice that received 20 ml/liter in drinking water for 8 months), and a control group (15 mice that received no treatment). To estimate the therapeutic effect of the Z. multiflora AW on the hydatid cyst, after 8 months of infection, the 15 remaining mice were allocated into three experimental treatment groups of five animals each, including the albendazole group (300 mg/kg/day for 20 days), Z. multiflora AW group (40 ml/liter in drinking water for 30 days), and control group (no treatment). All mice were then euthanized, and the sizes and weights of the cysts as well as their ultrastructural changes were investigated. The weights and sizes of the hydatid cysts significantly decreased upon treatment with the Z. multiflora AW in both the preventive and therapeutic groups (P < 0.05). The results of scanning electron microscopy also showed considerable damage in the germinal layer of the hydatid cysts recovered from the treated animals. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Oliveria decumbens essential oil: Chemical compositions and antimicrobial activity against the growth of some clinical and standard strains causing infection.

PubMed

Alizadeh Behbahani, Behrooz; Tabatabaei Yazdi, Farideh; Vasiee, Alireza; Mortazavi, Seyed Ali

2018-01-01

Oliveria decumbens as a valuable medicinal plant is extensively used in traditional medicine. clinical and standard strains causing infection resistance to antimicrobial agents, is one of the important problems in medicine. The aim of this study was to investigate the antibacterial activities and phytochemical analysis of Oliveria decumbens essential oil on the growth of some clinical and standard strains causing infection (Pseudomonas aerogenes, Escherichia coli, Streptococcus pyogenes and Staphylococcus epidermidis). Oliveria decumbens essential oil composition was identified by gas chromatography/mass spectrometry. Phytochemical analysis (alkaloids, saponins, flavone and phenolic) essential oil of the Oliveria decumbens were appraised based on qualitative methods. Several methods (disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)) were used to appraise the antibacterial activity of the Oliveria decumbens essential oil. Thymol (28.45%) was the major compound of Oliveria decumbens essential oil. The total phenolics content (TPC) of the essential oil positively correlated with antioxidant activity (AA). The TPC and AA of Oliveria decumbens essential oil was equal to 92.45 ± 0.70 μg GAE/mg and 164.45 ± 1.20 μg/ml, respectively. The MIC of Oliveria decumbens essential oil ranged from 1 to 8 mg/ml depending on the type of bacteria (clinical and standard strains). The MBC of Oliveria decumbens essential oil varied from 1 mg/ml to 16 mg/ml. The smallest inhibition zone diameter (IZD) on different Oliveria decumbens essential oil concentrations on P. aeruginosa. Results indicate that Oliveria decumbens essential oil can prove to be an important source of AA and antibacterial and may be used for the treatment of infection diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Essential oils--their antimicrobial activity against Escherichia coli and effect on intestinal cell viability.

PubMed

Fabian, Dusan; Dusan, Fabian; Sabol, Marián; Marián, Sabol; Domaracká, Katarína; Katarína, Domaracká; Bujnáková, Dobroslava; Dobroslava, Bujnáková

2006-12-01

Essential oils are known to possess antimicrobial activity against a wide spectrum of bacteria. The main objective of this study was to evaluate possible harmful effects of four commonly used essential oils and their major components on intestinal cells. Antimicrobial activity of selected plant extracts against enteroinvasive Escherichia coli was dose dependent. However, doses of essential oils with the ability to completely inhibit bacterial growth (0.05%) showed also relatively high cytotoxicity to intestinal-like cells cultured in vitro. Lower doses of essential oils (0.01%) had only partial antimicrobial activity and their damaging effect on Caco-2 cells was only modest. Cell death assessment based on morphological and viability staining followed by fluorescence microscopy showed that essential oils of cinnamon and clove and their major component eugenol had almost no cytotoxic effect at lower doses. Although essential oil of oregano and its component carvacrol slightly increased the incidence of apoptotic cell death, they showed extensive antimicrobial activity even at lower concentrations. Relatively high cytotoxicity was demonstrated by thyme oil, which increased both apoptotic and necrotic cell death incidence. In contrast, its component thymol showed no cytotoxic effect as well as greatly-reduced ability to inhibit visible growth of the chosen pathogen in the doses used. On the other hand, the addition of all essential oils and their components at lower doses, with the exception of thyme oil, to bacterial suspension significantly reduced the cytotoxic effect of E. coli on Caco-2 cells after 1h culture. In conclusion, it is possible to find appropriate doses of essential oils showing both antimicrobial activity and very low detrimental effect on intestinal cells.

Development of antioxidant packaging material by applying corn-zein to LLDPE film in combination with phenolic compounds.

PubMed

Park, Hye-Yeon; Kim, Sung-Jin; Kim, Ki Myong; You, Young-Sun; Kim, So Yeon; Han, Jaejoon

2012-10-01

Functional active packaging materials were successfully developed by incorporating antioxidant agents into corn-zein-laminated linear low-density polyethylene (LLDPE) film. The minimum effective concentrations of the active compounds (for example, thymol, carvacrol, eugenol) were determined and these compounds were then laminated into LLDPE films to develop corn-zein-laminated films with antioxidant agents. The release rate of antioxidant agents in gas and liquid media were determined along with the mechanical and water barrier properties of the films containing these compounds. Tensile strength and percentage elongation at break were reduced in the corn-zein-laminated LLDPE films when compared to typical LLDPE film. Furthermore, the ability of the corn-zein-laminated films to repel moisture decreased by approximately 12.2%, but was improved by incorporating hydrophobic antioxidant compounds in the corn-zein layer. Examination of release kinetics in the gas and liquid phases verified that antioxidants were effectively released from the films and inhibited oxidation during testing. Finally, the films were used for fresh ground beef packaging, and effectively inhibited lipid oxidation and had a positive effect on the color stability of beef patties during storage. These results indicate that the developed antioxidant films are a novel active packaging material that can be effectively implemented by the food industry to improve the quality and safety of foods. Zein protein, a by-product of corn processing industry, was laminated into plastic films in combination with natural phenolic compounds to develop antioxidant packaging films. The films demonstrated their efficient release patterns of antioxidant compounds, which are suitable for packaging applications and food protection. © 2012 Institute of Food Technologists®

Efficacy of plant essential oils on postharvest control of rots caused by fungi on different stone fruits in vivo.

PubMed

Lopez-Reyes, Jorge Giovanny; Spadaro, Davide; Prelle, Ambra; Garibaldi, Angelo; Gullino, Maria Lodovica

2013-04-01

The antifungal activity of plant essential oils was evaluated as postharvest treatment on stone fruit against brown rot and grey mold rot of stone fruit caused by Monilinia laxa and Botrytis cinerea, respectively. The essential oils from basil (Ocimum basilicum), fennel (Foeniculum sativum), lavender (Lavandula officinalis), marjoram (Origanum majorana), oregano (Origanum vulgare), peppermint (Mentha piperita), rosemary (Rosmarinus officinalis), sage (Salvia officinalis), savory (Satureja montana), thyme (Thymus vulgaris), and wild mint (Mentha arvensis) were tested at two different concentrations on apricots (cv. Kyoto and cv. Tonda di Costigliole), nectarines (cv. Big Top and cv. Nectaross) and plums (cv. Italia and cv. TC Sun). The volatile composition of the essential oils tested was determined by gas chromatography-mass spectrometry analysis. The treatments containing essential oils from oregano, savory, and thyme at 1% (vol/vol) controlled both B. cinerea and M. laxa growing on apricots cv. Tonda di Costigliole and plums cv. Italia and cv. TC Sun; however, the same treatments were phytotoxic for the carposphere of nectarines cv. Big Top and cv. Nectaross. Treatments with 10% (vol/vol) essential oils were highly phytotoxic, notwithstanding their efficacy against the pathogens tested. The essential oils containing as major components α-pinene, p-cymene, carvacrol, and thymol showed similar results on stone fruit, so their antimicrobial activity and the phytotoxicity produced could be based on the concentration of their principal compounds and their synergistic activity. The efficacy of the essential oil treatments on control of fungal pathogens in postharvest depended on the fruit cultivar, the composition and concentration of the essential oil applied, and the length of storage.

The bovine TRPV3 as a pathway for the uptake of Na+, Ca2+, and NH4+

PubMed Central

Liebe, Franziska; Liebe, Hendrik

2018-01-01

Absorption of ammonia from the gastrointestinal tract results in problems that range from hepatic encephalopathy in humans to poor nitrogen efficiency of cattle with consequences for the global climate. Previous studies on epithelia and cells from the native ruminal epithelium suggest functional involvement of the bovine homologue of TRPV3 (bTRPV3) in ruminal NH4+ transport. Since the conductance of TRP channels to NH4+ has never been studied, bTRPV3 was overexpressed in HEK-293 cells and investigated using the patch-clamp technique and intracellular calcium imaging. Control cells contained the empty construct. Divalent cations blocked the conductance for monovalent cations in both cell types, with effects higher in cells expressing bTRPV3. In bTRPV3 cells, but not in controls, menthol, thymol, carvacrol, or 2-APB stimulated whole cell currents mediated by Na+, Cs+, NH4+, and K+, with a rise in intracellular Ca2+ observed in response to menthol. While only 25% of control patches showed single-channel events (with a conductance of 40.8 ± 11.9 pS for NH4+ and 25.0 ± 5.8 pS for Na+), 90% of bTRPV3 patches showed much larger conductances of 127.8 ± 4.2 pS for Na+, 240.1 ± 3.6 pS for NH4+, 34.0 ± 1.7 pS for Ca2+, and ~ 36 pS for NMDG+. Open probability, but not conductance, rose with time after patch excision. In conjunction with previous research, we suggest that bTRPV3 channels may play a role in the transport of Na+, K+, Ca2+ and NH4+ across the rumen with possible repercussions for understanding the function of TRPV3 in other epithelia. PMID:29494673

Evidence for the functional involvement of members of the TRP channel family in the uptake of Na(+) and NH4 (+) by the ruminal epithelium.

PubMed

Rosendahl, Julia; Braun, Hannah S; Schrapers, Katharina T; Martens, Holger; Stumpff, Friederike

2016-08-01

Large quantities of protein are degraded in the fermentative parts of the gut to ammonia, which is absorbed, detoxified to urea, and excreted, leading to formation of nitrogenous compounds such as N2O that are associated with global warming. In ruminants, channel-mediated uptake of NH4 (+) from the rumen predominates. The molecular identity of these channels remains to be clarified. Ruminal cells and epithelia from cows and sheep were investigated using patch clamp, Ussing chamber, microelectrode techniques, and qPCR. In patch clamp experiments, bovine ruminal epithelial cells expressed a conductance for NH4 (+) that could be blocked in a voltage-dependent manner by divalent cations. In the native epithelium, NH4 (+) depolarized the apical potential, acidified the cytosol and induced a rise in short-circuit current (I sc) that persisted after the removal of Na(+), was blocked by verapamil, enhanced by the removal of divalent cations, and was sensitive to certain transient receptor potential (TRP) channel modulators. Menthol or thymol stimulated the I sc in Na(+) or NH4 (+) containing solutions in a dose-dependent manner and modulated transepithelial Ca(2+) fluxes. On the level of messenger RNA (mRNA), ovine and bovine ruminal epithelium expressed TRPA1, TRPV3, TRPV4, TRPM6, and TRPM7, with any expression of TRPV6 marginal. No bands were detected for TRPV1, TRPV5, or TRPM8. Functional and molecular biological data suggest that the transport of NH4 (+), Na(+), and Ca(2+) across the rumen involves TRP channels, with TRPV3 and TRPA1 emerging as prime candidate genes. TRP channels may also contribute to the transport of NH4 (+) across other epithelia.

The bovine TRPV3 as a pathway for the uptake of Na+, Ca2+, and NH4.

PubMed

Schrapers, Katharina T; Sponder, Gerhard; Liebe, Franziska; Liebe, Hendrik; Stumpff, Friederike

2018-01-01

Absorption of ammonia from the gastrointestinal tract results in problems that range from hepatic encephalopathy in humans to poor nitrogen efficiency of cattle with consequences for the global climate. Previous studies on epithelia and cells from the native ruminal epithelium suggest functional involvement of the bovine homologue of TRPV3 (bTRPV3) in ruminal NH4+ transport. Since the conductance of TRP channels to NH4+ has never been studied, bTRPV3 was overexpressed in HEK-293 cells and investigated using the patch-clamp technique and intracellular calcium imaging. Control cells contained the empty construct. Divalent cations blocked the conductance for monovalent cations in both cell types, with effects higher in cells expressing bTRPV3. In bTRPV3 cells, but not in controls, menthol, thymol, carvacrol, or 2-APB stimulated whole cell currents mediated by Na+, Cs+, NH4+, and K+, with a rise in intracellular Ca2+ observed in response to menthol. While only 25% of control patches showed single-channel events (with a conductance of 40.8 ± 11.9 pS for NH4+ and 25.0 ± 5.8 pS for Na+), 90% of bTRPV3 patches showed much larger conductances of 127.8 ± 4.2 pS for Na+, 240.1 ± 3.6 pS for NH4+, 34.0 ± 1.7 pS for Ca2+, and ~ 36 pS for NMDG+. Open probability, but not conductance, rose with time after patch excision. In conjunction with previous research, we suggest that bTRPV3 channels may play a role in the transport of Na+, K+, Ca2+ and NH4+ across the rumen with possible repercussions for understanding the function of TRPV3 in other epithelia.

Novel polymeric micelles for insect pest control: encapsulation of essential oil monoterpenes inside a triblock copolymer shell for head lice control

PubMed Central

Guzmán, Eduardo; Ortega, Francisco; Rubio, Ramón G.

2017-01-01

Background Essential oil components (EOCs) are molecules with interesting application in pest control, these have been evaluated against different insect pest from more than 100 years, but their practical use is rather limited. Thus, the enhancement of their bioavailability and manageability due to their dispersion in water can open new perspective for the preparation of formulations for the control of insect pest. In this work, we studied the encapsulation of different monoterpenes in a poloxamer shell in order to prepare aqueous formulations that can be used for the development of platforms used in pest control. Methods Micellar systems containing a 5 wt% of poloxamer 407 and 1.25 wt% of the different monoterpenes were prepared. Dynamic Light Scattering (DLS) experiments were carried out to characterize the dispersion of the EOCs in water. The pediculicidal activity of these micellar systems was tested on head lice using an ex vivo immersion test. Results The poloxamers allowed the dispersion of EOCs in water due to their encapsulation inside the hydrophobic core of the copolymer micelles. From this study, we concluded that it is possible to make stable micellar systems containing water (>90 wt%), 1.25 wt% of different monoterpenes and a highly safe polymer (5wt% Poloxamer 407). These formulations were effective against head lice with mortality ranging from 30 to 60%, being the most effective emulsions those containing linalool, 1,8-cineole, α-terpineol, thymol, eugenol, geraniol and nonyl alcohol which lead to mortalities above 50%. Discussion Since these systems showed good pediculicidal activity and high physicochemical stability, they could be a new route for the green fabrication of biocompatible and biosustainable insecticide formulations. PMID:28439460

Anti-tubercular activity of eleven aromatic and medicinal plants occurring in Colombia.

PubMed

Bueno-Sánchez, Juan Gabriel; Martínez-Morales, Jairo René; Stashenko, Elena E; Ribón, Wellman

2009-03-01

Human tuberculosis is a contagious-infectious disease mainly caused by Mycobacterium tuberculosis. Although regimens exist for treating tuberculosis, they are far from ideal. Development of effective strategies for treatment of human tuberculosis has posed a challenge, considering the increase in infections associated with the human immunodeficiency virus and immunocompromised patients. Essential oils--volatile, aromatic oil extracts from plants--have been used in traditional treatment of many diseases; however careful investigation of these oils has not been undertaken with respect to treatments of tuberculosis. The in vitro antitubercular activity of essential oils from 11 medicinal plants grown in Colombia were assessed for efficacy as new medications (phytomedicines) for treatment of M. tuberculosis H37Rv. Essential oil extraction and analysis were performed as described Stashenko et al. (2004). Minimal inhibitory concentrations were determined by a colorimetric macrodilution method, following the protocol described by Abate et al. (1998). Isoniazide and rifampin were used as control treatments. Bactericidal and bacteriostatic activity was measured using the method developed by the Clinical and Laboratory Standards Institute consigned in the M26-A protocol. Essential oils from Achyrocline alata and Swinglea glutinosa were the most active with minimal inhibitory concentrations of 62.5 +/- 0.1 and 100 +/- 36 microg ml(-1), respectively. Carvacrol, thymol, p-cymene, 1,8-cineole, limonene, and beta-pinene were the major components, most often identified in the 11 plant extracts of essential oils. Time-kill curve assays demonstrated the bacteriostatic activity of these essential oils. The essential oils from A. alata and S. glutinosa plants, and the components identified therein, are candidates as potential phytotherapeutic agents for human tuberculosis control.

Pseudomonas aeruginosa cells adapted to benzalkonium chloride show resistance to other membrane-active agents but not to clinically relevant antibiotics.

PubMed

Loughlin, M F; Jones, M V; Lambert, P A

2002-04-01

Our objective was to determine whether strains of Pseudomonas aeruginosa can adapt to growth in increasing concentrations of the disinfectant benzalkonium chloride (BKC), and whether co-resistance to clinically relevant antimicrobial agents occurs. Attempts were made to determine what phenotypic alterations accompanied resistance and whether these explained the mechanism of resistance. Strains were serially passaged in increasing concentrations of BKC in static nutrient broth cultures. Serotyping and genotyping were used to determine purity of the cultures. Two strains were examined for cross-resistance to other disinfectants and antibiotics by broth dilution MIC determination. Alterations in outer membrane proteins and lipopolysaccharide (LPS) expressed were examined by SDS-PAGE. Cell surface hydrophobicity and charge, uptake of disinfectant and proportion of specific fatty acid content of outer and cytoplasmic membranes were determined. Two P. aeruginosa strains showed a stable increase in resistance to BKC. Co-resistance to other quaternary ammonium compounds was observed in both strains; chloramphenicol and polymyxin B resistance were observed in one and a reduction in resistance to tobramycin observed in the other. However, no increased resistance to other biocides (chlorhexidine, triclosan, thymol) or antibiotics (ceftazidime, imipenem, ciprofloxacin, tobramycin) was detected. Characteristics accompanying resistance included alterations in outer membrane proteins, uptake of BKC, cell surface charge and hydrophobicity, and fatty acid content of the cytoplasmic membrane, although no evidence was found for alterations in LPS. Each of the two strains had different alterations in phenotype, indicating that such adaptation is unique to each strain of P. aeruginosa and does not result from a single mechanism shared by the whole species.

The antibacterial effect of Ziziphora clinopodioides essential oil and nisinagainst Salmonella typhimurium and Staphylococcus aureus in doogh, a yoghurt-based Iranian drink.

PubMed

Shahbazi, Yasser

2016-01-01

Doogh is the most popular and commonly consumed yoghurt-based Iranian drink. The aim of this study was to investigate the antibacterial effects of Ziziphora clinopodioides essential oil (ZEO) at 0.10 and 0.20% concentrations, nisin at 250 and 500 IU mL -1 , and their combination against Salmonella typhimurium and Staphylococcus aureus in doogh during storage at 4 ˚C for  9 days. Nine batches were studied as follows: control: no ZEO or nisin added, A: 0.10% ZEO, B: 0.20% ZEO, C: 250 IU mL -1 nisin, D: 500 IU mL -1 nisin, E: 0.10% ZEO + 250 IU mL -1 nisin, F: 0.10% ZEO + 500 IU mL -1 nisin, G: 0.20% ZEO + 250 IU mL -1 nisin and H: 0.20% ZEO + 500 IU mL -1 nisin. Based on gas-chromatography and mass spectrometry, carvacrol (65.22%), thymol (19.51%), p -cymene (4.86%) and ɣ -terpinene (4.63%) were the major components of ZEO. The populations of S. typhimurium and S. aureus in samples treated with all concentrations of the ZEO and nisin were kept below 1 log CFU mL -1 on day 5 of storage, while the count of S . typhimurium and S. aureus was found as 2.72 ± 0.02 and 2.21 ± 0.00 log CFU mL -1 on day 5 for untreated samples, respectively. The ZEO separately and in combination with nisin, was very effective against these two common food-borne pathogens. The ZEO alone and in combination with nisin could be considered as a potential strong antimicrobial agent that can be used for the growth inhibition of aforementioned bacteria in food products especially doogh.

Nigella sativa L. and its bioactive constituents as hepatoprotectant: a review.

PubMed

Tabassum, Heena; Ahmad, Asad; Ahmad, Iffat Zareen

2018-04-26

The pharmacological properties of Nigella sativa L. are well attributed to the presence of bioactive compounds, mainly, thymoquinone (TQ), thymol (THY) and α hederin and their antioxidant effects. TQ,THY and alpha-hederin (α-hederin) provide protection to liver from injury via different mechanisms including inhibition of iron-dependent lipid peroxidation, elevation in total thiol content and (GSH) level, radical scavenging, increasing the activity of quinone reductase, catalase, superoxide dismutase(SOD) and glutathione transferase (GST), inhibition of NF-κB activity and inhibition of both (COX) and (LOX) protects liver from injuries. The main aim of this literature review is to reflect the relevant role of ROS in inducing hepatic diseases and also the preventive role of N. sativa L. in hepatic diseases. The present article is directed towards highlighting the beneficial contribution of researchers to explore the pharmacological actions with therapeutic potential of this precious natural herb and its bioactive compounds pertaining to the hepatoprotective effects. We systematically searched for research literature through well-framed review question and presented the data in the tabular forms for the convenience of the readers. Two hundred forty-one papers were embodied in this review, oxidative effect and the reactive oxygen species (ROS) are known to be the major causes of many diseases such as hepatic cancer. Many drugs and chemicals have shown to incite oxidative damage by generation of ROS in the body. Therefore, this review intent to focus the role of ROS in liver diseases and the mechanisms through which N. sativa prevents hepatic diseases. The mechanisms by which N. sativa impede progression in chronic liver diseases should be used as a preventive medicine in patients with hepatic disorders. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Acute toxicity and repellent activity of the Origanum scabrum Boiss. & Heldr. (Lamiaceae) essential oil against four mosquito vectors of public health importance and its biosafety on non-target aquatic organisms.

PubMed

Govindarajan, Marimuthu; Kadaikunnan, Shine; Alharbi, Naiyf S; Benelli, Giovanni

2016-11-01

The recent outbreaks of dengue, chikungunya, and Zika virus highlighted the pivotal importance of mosquito vector control in tropical and subtropical areas worldwide. However, mosquito control is facing hot challenges, mainly due to the rapid development of pesticide resistance in Culicidae and the limited success of biocontrol programs on Aedes mosquitoes. In this framework, screening botanicals for their mosquitocidal potential may offer effective and eco-friendly tools in the fight against mosquitoes. In the present study, the essential oil (EO) obtained from the medicinal plant Origanum scabrum was analyzed by GC-MS and evaluated for its mosquitocidal and repellent activities towards Anopheles stephensi, Aedes aegypti, Culex quinquefasciatus, and Culex tritaeniorhynchus. GC-MS analysis showed a total of 28 compounds, representing 97.1 % of the EO. The major constituents were carvacrol (48.2 %) and thymol (16.6 %). The EO was toxic effect to the A. stephensi, A. aegypti, C. quinquefasciatus, and C. tritaeniorhynchus larvae, with LC 50 of 61.65, 67.13, 72.45, and 78.87 μg/ml, respectively. Complete ovicidal activity was observed at 160, 200, 240, and 280 μg/ml, respectively. Against adult mosquitoes, LD 50 were 122.38, 134.39, 144.53, and 158.87 μg/ml, respectively. In repellency assays, the EOs tested at 1.0, 2.5, and 5.0 mg/cm 2 concentration of O. scabrum gave 100 % protection from mosquito bites up to 210, 180, 150, and 120 min, respectively. From an eco-toxicological point of view, the EO was tested on three non-target mosquito predators, Gambusia affinis, Diplonychus indicus, and Anisops bouvieri, with LC 50 ranging from 4162 to 12,425 μg/ml. Overall, the EO from O. scabrum may be considered as a low-cost and eco-friendly source of phytochemicals to develop novel repellents against Culicidae.

Anti-oxidant activity and major chemical component analyses of twenty-six commercially available essential oils.

PubMed

Wang, Hsiao-Fen; Yih, Kuang-Hway; Yang, Chao-Hsun; Huang, Keh-Feng

2017-10-01

This study analyzed 26 commercially available essential oils and their major chemical components to determine their antioxidant activity levels by measuring their total phenolic content (TPC), reducing power (RP), β-carotene bleaching (BCB) activity, trolox equivalent antioxidant capacity (TEAC), and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging (DFRS) ability. The clove bud and thyme borneol essential oils had the highest RP, BCB activity levels, and TPC values among the 26 commercial essential oils. Furthermore, of the 26 essential oils, the clove bud and ylang ylang complete essential oils had the highest TEAC values, and the clove bud and jasmine absolute essential oils had the highest DFRS ability. At a concentration of 2.5 mg/mL, the clove bud and thyme borneol essential oils had RP and BCB activity levels of 94.56% ± 0.06% and 24.64% ± 0.03% and 94.58% ± 0.01% and 89.33% ± 0.09%, respectively. At a concentration of 1 mg/mL, the clove bud and thyme borneol essential oils showed TPC values of 220.00 ± 0.01 and 69.05 ± 0.01 mg/g relative to gallic acid equivalents, respectively, and the clove bud and ylang ylang complete essential oils had TEAC values of 809.00 ± 0.01 and 432.33 ± 0.01 μM, respectively. The clove bud and jasmine absolute essential oils showed DFRS abilities of 94.13% ± 0.01% and 78.62% ± 0.01%, respectively. Phenolic compounds of the clove bud, thyme borneol and jasmine absolute essential oils were eugenol (76.08%), thymol (14.36%) and carvacrol (12.33%), and eugenol (0.87%), respectively. The phenolic compounds in essential oils were positively correlated with the RP, BCB activity, TPC, TEAC, and DFRS ability. Copyright © 2017. Published by Elsevier B.V.

The effect of phytogenic feed additives to substitute in-feed antibiotics on growth traits and blood biochemical parameters in broiler chicks challenged with Salmonella typhimurium.

PubMed

Abudabos, Alaeldein M; Alyemni, Abdullah H; Dafalla, Yousif M; Khan, Rifat Ullah

2016-12-01

There is a growing concern over the use of antibiotics due to the increased resistance of pathogens in broiler. The present study was designed to find the comparative effect of an antibiotic, and some phytogenic on performance traits, blood biochemical parameters, and antioxidant status during starter phase exposed to Salmonella typhimurium challenge. A total of 560-day-old broiler chicks (Ross 308) were randomly allocated to seven treatments (eight replicates). Control (basal diet); T1, infected with Salmonella enterica subsp. typhimurium; T2, infected + avilamycin at the rate of 0.2 g/kg; T3, infected + essential oil of thymol; T4, infected + phytogenic; T5, infected + anti-Salmonella organic acid; and T6, infected + essential oils of thyme, anise, and other components. Body weight gain and feed conversion ratio (FCR) were significantly (P < 0.05) high in the T2 and T5 at the end of the first and the second week and similar to T4. During the second week, European production efficiency factor (EPEF) was also significantly (P < 0.05) high in T2, T4 and T5. Blood albumin increased significantly (P < 0.05) in birds of T2 in the first week, while during the second week, blood glucose and triglyceride concentration decreased significantly (P < 0.05) in T5. Blood ALT concentration decreased significantly (P < 0.05) in T6 compared to other treatments in the second week. Total antioxidant capacity (at the end of the second week) and thiobarbituric acid reactive substances (TBARS) did not change significantly. From the results of the present study, it was concluded that different feed additives could be substituted with antibiotics in the feed of broiler exposed to S. typhimurium challenge.

Effect of blood contamination with 1-step self-etching adhesives on microtensile bond strength to dentin.

PubMed

Yoo, H M; Pereira, P N R

2006-01-01

This study evaluated the effect of blood contamination and decontamination methods on the microtensile bond strength of 1-step self-etching adhesive systems to dentin contaminated after adhesive application and light curing. Three commercially available "all-in-one" adhesives (One Up Bond F, Xeno III and Adper Prompt L-Pop) and 1 resin composite (Clearfil AP-X) were used. Third molars that had been stored in distilled water with 0.5% thymol at 4 degrees C were ground with #600 SiC paper under running water to produce a standardized smear layer. The specimens were randomly divided into groups according to the 3 adhesive systems. The adhesive systems were used under 3 conditions: no contamination, which was the control (C); contamination of the light-cured adhesive surface with blood and reapplication of adhesive (Contamination 1) and contamination of the light-cured adhesive surface with blood, then washing, drying and reapplication of the adhesive (Contamination 2). Following light curing of the adhesive, the resin composite was placed in 3 increments up to a 5-mm-thick layer on the bonded surface. All specimens were stored in distilled water at 37 degrees C for 24 hours. The microtensile bond strength was measured using a universal testing machine (EZ test), and data were analyzed by 1-way ANOVA followed by the Duncan test to make comparisons among the groups (p=0.05). After debonding, 5 specimens were selected from each group and examined in a scanning electron microscope to evaluate the modes of fracture. For all adhesives, contamination groups showed lower bond strength than the control (p<0.05). There was no statistically significant difference among the control groups (p>0.05). For Xeno III and Adper Prompt L-Pop, contamination group #2 showed the lowest bond strength among the groups (p<0.05). For One Up Bond F, contamination group #2 showed higher bond strength than contamination group #1 but showed no statistical significance between them (p>0.05).

Clinical and mycological evaluation of an herbal antifungal formulation in canine Malassezia dermatitis.

PubMed

Nardoni, S; Mugnaini, L; Pistelli, L; Leonardi, M; Sanna, V; Perrucci, S; Pisseri, F; Mancianti, F

2014-09-01

Malassezia pachydermatis is a common cause of more widespread dermatitis in dogs (CMD). Recurrences are common, and this disorder can be very troubling for both dogs and for the pet owner. The treatment of 20 dogs affected by dermatitis due to M. pachydermatis, with Malacalm(®), a commercially available mixture consisting of essential oils (Citrus aurantium 1%, Lavandula officinalis 1%, Origanum vulgare 0.5%, Origanum majorana 0.5%, Mentha piperita 0.5% and Helichrysum italicum var. italicum 0.5%, in sweet almond oil and coconut oil) is reported. The effectiveness of the whole mixture, of component essential oils and of their more represented compounds against clinical isolates was evaluated by a microdilution test. Twenty animals were topically administered the mixture twice daily for 1 month. Ten animals were treated with a conventional therapy based on ketoconazole 10mg/kg/day and chlorhexidine 2% twice a week for 3 weeks. At the end of both treatments animals significantly improved their clinical status. Adverse effects were never noticed. Follow-up visit performed on day 180th allowed to observe a recurrence of clinical signs in all the subjects treated conventionally, while not significant clinical changes were referred in dogs treated with Malacalm(®). The overall MIC value of Malacalm(®) was 0.3%. O. vulgare showed the lowest minimum inhibitory concentrations (MIC), being active at 0.8%, followed by M. piperita (1%), O. majorana (1.3%), C. aurantium (2%) and L. officinalis (4%) while H. italicum did not yield any antimycotic effect up to 10%. Active major compounds were thymol, carvacrol, p-cymene, 1,8-cineol, limonene and menthol. The phytotherapic treatment achieved a good clinical outcome, and no recurrence of skin disorders on day 180th was recorded. This herbal remedium appeared to be a safe tool for limiting recurrences of CMD. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Bergamot versus beetle: evidence for intraspecific chemical specialization

PubMed Central

Keefover-Ring, Ken

2015-01-01

A large proportion of phytophagous insects show host plant specificity (monophagy or oligophagy), often determined by host secondary chemistry. Yet, even specialists can be negatively affected by host chemistry at high levels or with novel compounds, which may manifest itself if their host species is chemically variable. This study tested for reciprocal effects of a specialist tortoise beetle (Physonota unipunctata) feeding on a host plant (Monarda fistulosa) with two monoterpene chemotypes [thymol (T) and carvacrol (C)] using a controlled field experiment where larvae fed on caged plants of both chemotypes, haphazardly collected natural plants with and without beetle damage, and growth chamber experiments where larvae that hatched and briefly fed on one chemotype were reared on either chemotype. In the field experiment, plant chemotype did not affect larval weight or length, but did influence larval survival with almost 8.3 % more surviving on T plants. Herbivores reduced seed head area (86.5 % decrease), stem mass (41.2 %) and stem height (21.1 %) of caged plants, but this was independent of host chemotype. Natural plants experienced similar reductions in these variables (74.0, 41.4 and 8.7 %) and T chemotypes were more frequently damaged. In the growth chamber, larval relative growth rate (RGR) differed for both feeding history and year. Larvae from T natal plants reared on T hosts grew at almost twice the rate of those from C and reared on T. Larvae from either T or C natal plants reared on C plants showed intermediate growth rates. Additional analyses revealed natal plant chemotype as the most important factor, with the RGR of larvae from T natal plants almost one-third higher than that of those from C natal plants. These cumulative results demonstrate intraspecific variation in plant resistance that may lead to herbivore specialization on distinct host chemistry, which has implications for the evolutionary trajectory of both the insect and plant species. PMID:26578745

Bergamot versus beetle: evidence for intraspecific chemical specialization.

PubMed

Keefover-Ring, Ken

2015-11-16

A large proportion of phytophagous insects show host plant specificity (monophagy or oligophagy), often determined by host secondary chemistry. Yet, even specialists can be negatively affected by host chemistry at high levels or with novel compounds, which may manifest itself if their host species is chemically variable. This study tested for reciprocal effects of a specialist tortoise beetle (Physonota unipunctata) feeding on a host plant (Monarda fistulosa) with two monoterpene chemotypes [thymol (T) and carvacrol (C)] using a controlled field experiment where larvae fed on caged plants of both chemotypes, haphazardly collected natural plants with and without beetle damage, and growth chamber experiments where larvae that hatched and briefly fed on one chemotype were reared on either chemotype. In the field experiment, plant chemotype did not affect larval weight or length, but did influence larval survival with almost 8.3 % more surviving on T plants. Herbivores reduced seed head area (86.5 % decrease), stem mass (41.2 %) and stem height (21.1 %) of caged plants, but this was independent of host chemotype. Natural plants experienced similar reductions in these variables (74.0, 41.4 and 8.7 %) and T chemotypes were more frequently damaged. In the growth chamber, larval relative growth rate (RGR) differed for both feeding history and year. Larvae from T natal plants reared on T hosts grew at almost twice the rate of those from C and reared on T. Larvae from either T or C natal plants reared on C plants showed intermediate growth rates. Additional analyses revealed natal plant chemotype as the most important factor, with the RGR of larvae from T natal plants almost one-third higher than that of those from C natal plants. These cumulative results demonstrate intraspecific variation in plant resistance that may lead to herbivore specialization on distinct host chemistry, which has implications for the evolutionary trajectory of both the insect and plant species. Published by Oxford University Press on behalf of the Annals of Botany Company.

In vitro and in vivo antimalarial activity of essential oils and chemical components from three medicinal plants found in northeastern Brazil.

PubMed

Mota, Magaly L; Lobo, Lis Tavares Coelho; Costa, José M Galberto da; Costa, Leandro S; Rocha, Hugo A O; Rocha e Silva, Luiz F; Pohlit, Adrian M; Neto, Valter F de Andrade

2012-05-01

The prophylactic and therapeutic arsenal against malaria is quite restricted and all the antimalarials currently in use have limitations. Thus, there is a need to investigate medicinal plants in the search for phytochemicals which can be developed into drugs. In our investigation, essential oils (EOs) were obtained from Vanillosmopsis arborea (Gardner) Baker, Lippia sidoides Cham. and Croton zehntneri Pax & K. Hoffm., aromatic plants abundant in northeastern Brazil, which are found in the caatinga region and are used in traditional medicine. The chemical composition of these EOs was characterized by GC-MS, and monoterpenes and sesquiterpenes were well represented. We assessed the in vitro activity of these EOs and also individual EO chemical components against the human malaria parasite Plasmodium falciparum (K1 strain) and the in vivo activity of EOs in mice infected with Plasmodium berghei. The acute toxicity of these oils was assessed in healthy mice and in vitro cytotoxicity was determined at different concentrations against HeLa cells and mice macrophages. The EO of V. Arborea was partially active only when using the subcutaneous route (inhibited from 33 up to 47 %). In relation to the EOs, L. sidoides and C. zehntneri were active only by the oral route (per gavage) and partially inhibited the growth of P. berghei from 43 up to 55 % and showed good activity against P. falciparum in vitro (IC (50) = 7.00, 10.50, and 15.20 µg/mL, respectively). Individual EO constituents α-bisabolol, estragole, and thymol also exhibited good activity against P. falciparum (IC (50) = 5.00, 30.70, and 4.50 µg/mL, respectively). This is the first study showing evidence for the antimalarial activity of these species from northeastern Brazil and the low toxicity of their EOs. © Georg Thieme Verlag KG Stuttgart · New York.

Evaluation of antioxidant and antimicrobial activities of essential oils from Carum copticum seed and Ferula assafoetida latex.

PubMed

Kavoosi, Gholamreza; Tafsiry, Asad; Ebdam, Ali Asghar; Rowshan, Vahid

2013-02-01

Carum copticum and Ferula assafoetida have several medicinal properties including antispasmodic, carminative, sedative, analgesic, and antiseptic. Reactive oxygen species (ROS), reactive nitrogen species (RNS), hydrogen peroxide (H(2) O(2) ), and thiobarbituric acid reactive substances (TBARS) scavenging activities of Carum and Ferula oils along with their antibacterial and antifungal activities were examined. Thymol (40.25%), γ-terpinene (38.7%) and p-cymene (15.8%) were detected as the main components of Carum oil while, β-pinene (47.1%), α-pinene (21.36%), and 1, 2-dithiolane (18.6%) were the main components of Ferula oil. Inhibitory concentrations (IC50) for total radical scavenging were between 40 and 60 and 130 and 160 μg/mL of Carum and Ferula oil, respectively. Minimal inhibitory concentration (MIC) for Salmonella typhi, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Aspergillus niger, and Candida albicans were 78 ± 8, 65 ± 7, 14 ± 3, 5 ± 2, 5.6 ± 1.3, and 8.8 ± 2.2 μg/mL of Carum oil, respectively. MIC for S. typhi, E. coli, S. aureus, B. subtilis, A. niger, and C. albicans were >200, >200, 125 ± 17, 80 ± 12, 85 ± 5, and 90 ± 11 μg/mL of Ferula oil, respectively. Accordingly, Carum and Ferula oils could be used as safe and effective natural antioxidants to improve the oxidative stability of fatty foods during storage and to preserve foods against food burn pathogens. This study clearly demonstrates the potential of Carum and Ferula oil especially Carum oil as natural antioxidant and antimicrobial agent. The chemical composition of essential oils was identified. Thus, identification of such compounds also helps to discover of new antioxidant, antibacterial and antifungal agents for potential applications in food safety and food preservation. © 2013 Institute of Food Technologists®

Effect of essential oil from fresh leaves of Ocimum gratissimum L. on mycoflora during storage of peanuts in Benin.

PubMed

Adjou, Euloge S; Kouton, Sandrine; Dahouenon-Ahoussi, Edwige; Soumanou, Mohamed M; Sohounhloue, Dominique C K

2013-02-01

The aim of this study was to evaluate the effect of essential oil from fresh leaves of Sweet Fennel (Ocimum gratissimum) on mycoflora and Aspergillus section Flavi populations in stored peanuts. Aspergillus, Fusarium and Mucor spp. were the most common genera identified from peanuts at post-harvest in Benin by using a taxonomic schemes primarily based on morphological characters of mycelium and conidia. The isolated fungi include Aspergillus niger, A. parasiticus, A. flavus, A. ochraceus, Fusarium graminearum, F. solani, F. oxysporum and Mucor spp. The most prevalent fungi recorded were A. niger (94.18 %), A. flavus (83.72 %), A. parasiticus (77.90 %), A. ochraceus (72.09 %), F. graminearum (59.30 %) and F. oxysporum (51.16 %). Antifungal assay, performed by the agar medium assay, indicated that essential oil exhibited high antifungal activity against the growth of A. flavus, A. parasiticus, A. ochraceus and F. oxysporium. The minimal inhibitory concentration (MIC) of the essential oil was found to be 7.5 μl/ml for A. flavus and A. parasiticus and 5.5 μl/ml for A. ochraceus and F. oxysporium. The minimal fungicidal concentration (MFC) was recorded to be 8.0 μl/ml for A. flavus and A. parasiticus, 6,5 μl/ml for A. ochraceus and 6.0 μl/ml for F. oxysporium. The essential oil was found to be strongly fungicidal and inhibitory to aflatoxin production. Chemical analysis by GC/MS of the components of the oil led to the identification of 31 components characterized by myrcene (6.4 %), α-thujene (8.2 %), p-cymene (17.6 %), γ-terpinene (20.0 %), and thymol (26.9 %) as major components. The essential oil of Sweet Fennel, with fungal growth and mycotoxin inhibitory properties, offers a novel approach to the management of storage, thus opening up the possibility to prevent mold contamination in stored peanuts.

The repeatability of three diagnostic methods (visual using ICDAS II, laser fluorescence, and radiographic) for early caries detection

NASA Astrophysics Data System (ADS)

Sukmasari, S.; Lestari, W.; Ko, B. B.; Noh, Z.; Asmail, N.; Yaacob, N.

2017-08-01

Newly introduced ICDAS II as a visual method, laser fluorescence as another technique that have ability to quantify early mineral loss of tooth structure and intra oral radiograph, are methods can be used in the clinic. To provide standardization for comprehensive caries management at an early stage, all methods supposed to be tested between users. The objective of this research is to evaluate the repeatability of each system. It is a comparative cross sectional study using 100 extracted permanent teeth without obvious cavitation (premolar & molar) that were collected and stored in thymol solution. The teeth were embedded on the wax block and labeled with numbers. All 5 surfaces were examined by 5 examiners using visual (ICDAS II), laser fluorescence (LF) and radiographic examination. The data were then analyzed to measure intra and inter examiner repeatability using Cronbach’s alpha and inter-item correlation matrix. Intra-examiner repeatability for all examiners was >0.7. Chronbach’s a value for inter-examiner repeatability for ICDAS II was >0.8 on 3 surfaces except on buccal and lingual. LF exhibit repeatability of >0.8 on all surfaces. Radiograph shows a low value of inter examiner repeatability (<0.7). Lecturer examiners showed the highest agreement followed by undergraduate students for inter-item correlation while the 2nd and 3rd reading of LF displays the best agreement. ICDAS II score favors more non-invasive treatment compared to LF. ICDAS II showed good repeatability except on buccal and lingual surfaces. In line with some of the previous study, ICDAS II is applicable for caries detection in daily clinical basis. Laser fluorescence exhibits the highest repeatability while the radiograph showed weak inter-examiner repeatability. Treatment decisions of ICDAS II propose more preventive treatment for early caries lesions compared to laser fluorescence.

Effect of CO2 Laser and Fluoride Varnish Application on Microhardness of Enamel Surface Around Orthodontic Brackets

PubMed Central

Mahmoudzadeh, Majid; Rezaei-Soufi, Loghman; Farhadian, Nasrin; Jamalian, Seyed Farzad; Akbarzadeh, Mahdi; Momeni, Mohammadali; Basamtabar, Masome

2018-01-01

Introduction: Orthodontic treatment has many advantages such as esthetic improvement and self-esteem enhancement; yet it has some disadvantages such as increasing the risk of formation of white spot lesions, because it makes oral hygiene more difficult. It is rational to implement procedures to prevent these lesions. The present study was aimed to assess the effect of CO2 laser and fluoride varnish on the surface of the enamel surface microhardness around the orthodontic braces. Methods: Eighty extracted premolar teeth were selected, scaled, polished with nonfluoridated pumic and metal brackets were bonded to them. Then, they were randomly allocated to 5 groups: control (neither fluoride nor laser is used on enamel surfaces), fluoride (4 minutes fluoride varnish treatment of the enamel surfaces), CO2 laser (10.6 µm CO2 laser irradiation of the teeth), laserfluoride (fluoride application after laser irradiation) and fluoride-laser (fluoride was applied and then teeth were irradiated with laser). After surface treatment around brackets on enamel, the samples were stored in 0.1% thymol for less than 5 days and then they were exposed to a 10-day microbiological caries model. Microhardness values of enamel were evaluated with Vickers test. One sample of each group (5 teeth from 80 samples) was prepared for SEM (scanning electron microscopy) and the data from 75 remaining teeth were analyzed with analysis of variance (ANOVA) and chi-square tests (α =0.05). Results: Microhardness mean values from high to low were as follow: fluoride-laser, laser-fluoride, laser, fluoride and control. Microhardness in fluoride-laser group was significantly higher compared with that of the control group. Distribution adhesive remnant index (ARI) scores were significantly different between groups and most of bond failures occurred at the enamel-adhesive interface in groups 2 to 5 and at the adhesive-bracket interface in the control group. Conclusion: Combination of fluoride varnish and CO2 laser irradiation can reduce enamel demineralization around orthodontic brackets. PMID:29399311

Effect of CO2 Laser and Fluoride Varnish Application on Microhardness of Enamel Surface Around Orthodontic Brackets.

PubMed

Mahmoudzadeh, Majid; Rezaei-Soufi, Loghman; Farhadian, Nasrin; Jamalian, Seyed Farzad; Akbarzadeh, Mahdi; Momeni, Mohammadali; Basamtabar, Masome

2018-01-01

Introduction: Orthodontic treatment has many advantages such as esthetic improvement and self-esteem enhancement; yet it has some disadvantages such as increasing the risk of formation of white spot lesions, because it makes oral hygiene more difficult. It is rational to implement procedures to prevent these lesions. The present study was aimed to assess the effect of CO 2 laser and fluoride varnish on the surface of the enamel surface microhardness around the orthodontic braces. Methods: Eighty extracted premolar teeth were selected, scaled, polished with nonfluoridated pumic and metal brackets were bonded to them. Then, they were randomly allocated to 5 groups: control (neither fluoride nor laser is used on enamel surfaces), fluoride (4 minutes fluoride varnish treatment of the enamel surfaces), CO 2 laser (10.6 µm CO 2 laser irradiation of the teeth), laserfluoride (fluoride application after laser irradiation) and fluoride-laser (fluoride was applied and then teeth were irradiated with laser). After surface treatment around brackets on enamel, the samples were stored in 0.1% thymol for less than 5 days and then they were exposed to a 10-day microbiological caries model. Microhardness values of enamel were evaluated with Vickers test. One sample of each group (5 teeth from 80 samples) was prepared for SEM (scanning electron microscopy) and the data from 75 remaining teeth were analyzed with analysis of variance (ANOVA) and chi-square tests (α =0.05). Results: Microhardness mean values from high to low were as follow: fluoride-laser, laser-fluoride, laser, fluoride and control. Microhardness in fluoride-laser group was significantly higher compared with that of the control group. Distribution adhesive remnant index (ARI) scores were significantly different between groups and most of bond failures occurred at the enamel-adhesive interface in groups 2 to 5 and at the adhesive-bracket interface in the control group. Conclusion: Combination of fluoride varnish and CO2 laser irradiation can reduce enamel demineralization around orthodontic brackets.

Decontamination of Escherichia coli O157:H7 on green onions using pulsed light (PL) and PL-surfactant-sanitizer combinations.

PubMed

Xu, Wenqing; Chen, Haiqiang; Huang, Yaoxin; Wu, Changqing

2013-08-16

Imported green onion has been associated with three large outbreaks in the USA. Contamination has been found on both domestic and imported green onions. The objective of our study was to investigate Escherichia coli O157:H7 inactivation efficacy of pulsed light (PL) as well as its combination with surfactant and/or sanitizers on green onions. Green onions were cut into two segments, stems and leaves, to represent two different matrixes. Stems were more difficult to be decontaminated. Spot and dip inoculation methods were compared and dipped inoculated green onions were found to be more difficult to be decontaminated. Results showed that 5s dry PL (samples were not immersed in water during PL treatment) and 60s wet PL (samples were immersed in water and stirred during PL treatment) treatments provided promising inactivation efficacy (>4log10CFU/g) for spot inoculated stems and leaves. For dip inoculated green onions, 60s wet PL treatment was comparable with 100ppm chlorine washing, demonstrating that PL could be used as an alternative to chlorine. To further increase the degree of microbial inactivation, combined treatments were applied. PL combined with surfactant (SDS) was found to be more effective than single treatments of PL, SDS, chlorine, citric acid, thymol, and hydrogen peroxide, and binary combined treatments of PL with one of those chemicals. Addition of chlorine or hydrogen peroxide to the PL-SDS combination did not further enhanced its microbial inactivation efficacy. The combination of PL and 1000ppm of SDS reduced the E. coli O157:H7 populations dip inoculated on the stems and leaves of green onions by 1.4 and 3.1log10CFU/g, respectively. Our findings suggest that PL could potentially be used for decontamination of E. coli O157:H7 on green onions, with wet PL added with SDS being the most effective PL treatment. © 2013.

Flurbiprofen–antioxidant mutual prodrugs as safer nonsteroidal anti-inflammatory drugs: synthesis, pharmacological investigation, and computational molecular modeling

PubMed Central

Ashraf, Zaman; Alamgeer; Kanwal, Munazza; Hassan, Mubashir; Abdullah, Sahar; Waheed, Mamuna; Ahsan, Haseeb; Kim, Song Ja

2016-01-01

Flurbiprofen–antioxidant mutual prodrugs were synthesized to reduce the gastrointestinal (GI) effects associated with flurbiprofen. For reducing the GI toxicity, the free carboxylic group (–COOH) was temporarily masked by esterification with phenolic –OH of natural antioxidants vanillin, thymol, umbelliferone, and sesamol. The in vitro hydrolysis of synthesized prodrugs showed that they were stable in buffer solution at pH 1.2, indicating their stability in the stomach. The synthesized prodrugs undergo significant hydrolysis in 80% human plasma and thus release free flurbiprofen. The minimum reversion was observed at pH 1.2, suggesting that prodrugs are less irritating to the stomach than flurbiprofen. The anti-inflammatory, analgesic, antipyretic, and ulcerogenic activities of prodrugs were evaluated. All the synthesized prodrugs significantly (P<0.001) reduced the inflammation against carrageenan and egg albumin-induced paw edema at 4 hours of study. The reduction in the size of the inflamed paw showed that most of the compounds inhibited the later phase of inflammation. The prodrug 2-oxo-2H-chromen-7-yl-2-(2-fluorobiphenyl-4-yl)propanoate (4b) showed significant reduction in paw licking with percentage inhibition of 58%. It also exhibited higher analgesic activity, reducing the number of writhes with a percentage of 75%, whereas flurbiprofen showed 69% inhibition. Antipyretic activity was investigated using brewer’s yeast-induced pyrexia model, and significant (P<0.001) reduction in rectal temperature was shown by all prodrugs at all times of assessment. The results of ulcerogenic activity showed that all prodrugs produced less GI irritation than flurbiprofen. Molecular docking and simulation studies were carried out with cyclooxygenase (COX-1 and COX-2) proteins, and it was observed that our prodrugs have more potential to selectively bind to COX-2 than to COX-1. It is concluded that the synthesized prodrugs have promising pharmacological activities with reduced GI adverse effects than the parent drug. PMID:27555750

Flurbiprofen-antioxidant mutual prodrugs as safer nonsteroidal anti-inflammatory drugs: synthesis, pharmacological investigation, and computational molecular modeling.

PubMed

Ashraf, Zaman; Alamgeer; Kanwal, Munazza; Hassan, Mubashir; Abdullah, Sahar; Waheed, Mamuna; Ahsan, Haseeb; Kim, Song Ja

2016-01-01

Flurbiprofen-antioxidant mutual prodrugs were synthesized to reduce the gastrointestinal (GI) effects associated with flurbiprofen. For reducing the GI toxicity, the free carboxylic group (-COOH) was temporarily masked by esterification with phenolic -OH of natural antioxidants vanillin, thymol, umbelliferone, and sesamol. The in vitro hydrolysis of synthesized prodrugs showed that they were stable in buffer solution at pH 1.2, indicating their stability in the stomach. The synthesized prodrugs undergo significant hydrolysis in 80% human plasma and thus release free flurbiprofen. The minimum reversion was observed at pH 1.2, suggesting that prodrugs are less irritating to the stomach than flurbiprofen. The anti-inflammatory, analgesic, antipyretic, and ulcerogenic activities of prodrugs were evaluated. All the synthesized prodrugs significantly (P<0.001) reduced the inflammation against carrageenan and egg albumin-induced paw edema at 4 hours of study. The reduction in the size of the inflamed paw showed that most of the compounds inhibited the later phase of inflammation. The prodrug 2-oxo-2H-chromen-7-yl-2-(2-fluorobiphenyl-4-yl)propanoate (4b) showed significant reduction in paw licking with percentage inhibition of 58%. It also exhibited higher analgesic activity, reducing the number of writhes with a percentage of 75%, whereas flurbiprofen showed 69% inhibition. Antipyretic activity was investigated using brewer's yeast-induced pyrexia model, and significant (P<0.001) reduction in rectal temperature was shown by all prodrugs at all times of assessment. The results of ulcerogenic activity showed that all prodrugs produced less GI irritation than flurbiprofen. Molecular docking and simulation studies were carried out with cyclooxygenase (COX-1 and COX-2) proteins, and it was observed that our prodrugs have more potential to selectively bind to COX-2 than to COX-1. It is concluded that the synthesized prodrugs have promising pharmacological activities with reduced GI adverse effects than the parent drug.

[Micro-computed tomography of the vasculature in parenchymal organs and lung alveoli].

PubMed

Langheinrich, A C; Bohle, R M; Breithecker, A; Lommel, D; Rau, W S

2004-09-01

Micro-CT has become a powerful technique in non-destructive 3D imaging and morphometric analysis. First results were limited to the investigation of osteoporosis in cancellous bone. But the availability of systems with almost microscopic resolution and sufficient soft tissue contrast has opened up entirely new applications for laboratory investigation of blood vessels and soft tissues. This article gives an overview of micro-CT technology and the potential of three-dimensional imaging of the vessel wall and soft-tissue architecture imaging in different organs using different contrast perfusion and staining techniques. Micro-CT provides quantitative information on human plaque morphology equivalent to histomorphometric analysis. Based on differences in grey-scale attenuations, micro-CT also correctly identifies atherosclerotic lesions that are histologically classified as fibrous plaques, calcified lesions, fibroatheroma, and lipid rich lesions. Micro-CT is a promising method to visualize the architecture of the renal vasculature and, importantly, to separate cortex and medulla for the visualization of glomeruli and their afferent and efferent arterioles. Micro-CT can determine the vascular surface in a defined placental volume. Combining of micro-CT data and total placental volume enables an estimation of the approximate surface of the placental vasculature. The diameter of opacified vessels in the investigated samples ranged from 2 mm (chorion plate artery) to 14 micro m (smallest vessel diameter, terminal loop). Recognizing that lung parenchyma can only be visualized if the alveoli are completely expanded and the contrast of the thin alveolar walls is enhanced, we tested two preparation methods: (1) fixation of lung tissue with formalin vapour and staining with silver nitrate, and (2) intravenous injection of a barium sulfate-gelatine-thymol mixture in vivo in the anesthetized animal. We evaluated the ability of this mixture to enter the pulmonary microcirculation and the technical feasibility of micro-CT to assess lung micro-architecture.

Development of an antimicrobial material based on a nanocomposite cellulose acetate film for active food packaging.

PubMed

Rodríguez, Francisco J; Torres, Alejandra; Peñaloza, Ángela; Sepúlveda, Hugo; Galotto, María J; Guarda, Abel; Bruna, Julio

2014-01-01

Nanocomposites based on biopolymers have been recognised as potential materials for the development of new ecofriendly food packaging. In addition, if these materials incorporate active substances in their structure, the potential applications are much higher. Therefore, this work was oriented to develop nanocomposites with antimicrobial activity based on cellulose acetate (CA), a commercial organoclay Cloisite30B (C30B), thymol (T) as natural antimicrobial component and tri-ethyl citrate (TEC) as plasticiser. Nanocomposites were prepared by a solvent casting method and consisted of 5% (w/w) of C30B, 5% (w/w) of TEC and variable content of T (0%, 0.5% and 2% w/w). To evaluate the effect of C30B into the CA matrix, CA films without this organoclay but with T were also prepared. All nanocomposites showed the intercalation of CA into the organoclay structure; furthermore this intercalation was favoured when 2% (w/w) of T was added to the nanocomposite. In spite of the observed intercalation, the presence of C30B inside the CA matrices increased the opacity of the films significantly. On the other hand, T showed a plasticiser effect on the thermal properties of CA nanocomposites decreasing glass transition, melting temperature and melting enthalpy. The presence of T in CA nanocomposites also allowed the control de Listeria innocua growth when these materials were placed in contact with this Gram-positive bacterium. Interestingly, antimicrobial activity was increased with the presence of C30B. Finally, studies on T release showed that the clay structure inside the CA matrix did not affect its release rate; however, this nanofiller affected the partition coefficient KP/FS which was higher to CA nanocomposites films than in CA films without organoclay. The results obtained in the present study are really promising to be applied in the manufacture of food packaging materials.

The effect of terpene enhancer lipophilicity on the percutaneous permeation of hydrocortisone formulated in HPMC gel systems.

PubMed

El-Kattan, A F; Asbill, C S; Michniak, B B

2000-04-05

The percutaneous permeation of hydrocortisone (HC) was investigated in hairless mouse skin after application of an alcoholic hydrogel using a diffusion cell technique. The formulations contained one of 12 terpenes, the selection of which was based on an increase in their lipophilicity (log P 1.06-5.36). Flux, cumulative receptor concentrations, skin content, and lag time of HC were measured over 24 h and compared with control gels (containing no terpene). Furthermore, HC skin content and the solubility of HC in the alcoholic hydrogel solvent mixture in the presence of terpene were determined, and correlated to the enhancing activity of terpenes. The in vitro permeation experiments with hairless mouse skin revealed that the terpene enhancers varied in their ability to enhance the flux of HC. Nerolidol which possessed the highest lipophilicity (log P = 5.36+/-0.38) provided the greatest enhancement for HC flux (35.3-fold over control). Fenchone (log P = 2.13+/-0.30) exhibited the lowest enhancement of HC flux (10.1-fold over control). In addition, a linear relationship was established between the log P of terpenes and the cumulative amount of HC in the receptor after 24 h (Q(24)). Nerolidol, provided the highest Q(24) (1733+/-93 microg/cm(2)), whereas verbenone produced the lowest Q(24) (653+/-105 microg/cm(2)). Thymol provided the lowest HC skin content (1151+/-293 microg/g), while cineole produced the highest HC skin content (18999+/-5666 microg/g). No correlation was established between the log P of enhancers and HC skin content. A correlation however, existed between the log P of terpenes and the lag time. As log P increased, a linear decrease in lag time was observed. Cymene yielded the shortest HC lag time, while fenchone produced the longest lag time. Also, the increase in the log P of terpenes resulted in a proportional increase in HC solubility in the formulation solvent mixture.

Chemical composition and antioxidant, antimicrobial activities of the essential oils of Thymus marschallianus Will. and Thymus proximus Serg.

PubMed

Jia, H L; Ji, Q L; Xing, S L; Zhang, P H; Zhu, G L; Wang, X H

2010-01-01

Chemical composition and antioxidant, antimicrobial activities of the essential oils from Thymus marschallianus Will. and Thymus proximus Serg. growing in the wild in Xinjiang were studied. Samples were collected from the aerial parts of the plants with simultaneous distillation-extraction apparatus. The yields ranged between 1.22%+/- 0.01 and 0.16%+/- 0.01 (weight/dry weight), respectively, 53 and 60 kinds of volatiles, representing 99.6% and 99.7% of the essential oils, respectively, were identified in extracts from T. marschallianus and T. proximus by GC/MS analysis. The main components were Thymol (28.0% to 32.9%), p-Cymene (7.7% to 25.4%), and gamma-Terpinene (18.0% to 22.4%). Antioxidant activities of the oils were evaluated using metal chelating, reductive potential, 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, and modified thiobarbituric acid reactive substances assay. Antimicrobial activities of the oils were investigated on Escherichia coli, Staphylococcus aureus, Bacillus subtilis, yeast, Rhizopus, and Penicillium. The inhibition zones (IZ) and minimum inhibitory concentration (MIC) values were 5.0 to 35.7 mm in diameter and 1.81 to 4.52 microL/mL, respectively. Due to the economical impacts of spoiled foods and the consumer's concerns over the safety of foods, a lot of attention has been paid to naturally derived compounds. Fresh and dried Thymus species as well as their processed products have been widely used as flavorings since ancient times; however, during the last few decades, they also have become a subject for a search of natural antioxidants and antimicrobial agents. Biological activities of Thymus essential oils depend on their chemical composition, which is determined by the genotype and influenced by environmental conditions. Recent studies have showed that Thymus species have strong antimicrobial and antioxidant activities. To the best of our knowledge, the properties of Thymus species growing wild in the Xinjiang have not been reported before.

Effect of Origanum chemotypes on broiler intestinal bacteria.

PubMed

Betancourt, Liliana; Rodriguez, Fernando; Phandanouvong, Vienvilay; Ariza-Nieto, Claudia; Hume, Michael; Nisbet, David; Afanador-Téllez, German; Van Kley, Alexandra Martynova; Nalian, Armen

2014-10-01

Essential oils have been proposed as alternatives to antibiotic use in food animal production. This study evaluated 3 chemotypes of the Origanum genus, containing varying amounts of secondary metabolites carvacrol, thymol, and sabinene, in the broiler chicken diet. Aerial parts of Origanum vulgare L. (OL), O. vulgare L. ssp. hirtum (OH), and O. majorana (OM) were collected from a greenhouse located in the high altitude Sabana de Bogotá (Savanna of Bogotá) and O. vulgare L. ssp. hirtum (OG) produced and ground in Greece. Oregano essential oils (OEO) from these plants were obtained by steam distillation and analyzed by gas chromatography coupled to a mass spectrometer. Six treatments were evaluated: 200 mg/kg of OEO from OH, OL, and OM, 50 mg/kg of OEO from OG, 500 mg/kg of chlortetracycline, and without additives. Broiler chicks were maintained at 2,600 m above sea level, placed in brooder cages under a completely randomized design. Template DNA was isolated from duodenal, jejunal, ileal, and cecal contents in each group and bacterial 16S rDNA patterns were analyzed by denaturing gradient gel electrophoresis. Dendrograms of denaturing gradient gel electrophoresis band patterns revealed 2 main clusters, OEO-treated chicks and nontreated control chicks, in each intestinal segment. Band patterns from different gut compartments revealed major bacterial population shifts in the foregut (duodenum, jejunum, and ileum) compared with the hindgut (cecum and colon) at all ages evaluated (P < 0.05). The OEO groups showed less shift (62.7% similarity coefficient) between these 2 compartments versus the control groups (53.7% similarity coefficient). A reduction of 59% in mortality from ascites was seen in additive-supplemented groups compared with the control group. This study represents the first work to evaluate the effects of the 3 main chemotypes of Origanum genus in broilers. ©2014 Poultry Science Association Inc.

Comparative efficacies of Zataria multiflora essential oil and itraconazole against disseminated Candida albicans infection in BALB/c mice

PubMed Central

Khosravi, A.R.; Shokri, H.; Tootian, Z.; Alizadeh, M.; Yahyaraeyat, R.

2009-01-01

Disseminated candidiasis is a serious problem in public health that results from the invasion of Candida species, in particular Candida albicans. The aim of this study was to compare the efficacies of Zataria multiflora essential oil and itraconazole in clearing C. albicans from the visceral organs of BALB/c mice suffered from disseminated candidiasis. Zataria multiflora essential oil was extracted using Clevenger-type apparatus and analyzed by gas chromatography mass spectrometry (GC-MS). For clearance experiment, mice (20-25 g, N=8 per group) received essential oil at doses of 30, 48 and 64 mg/kg and itraconazole at dose of 200 mg/kg intraperitoneally (IP) 2 days before and after intravenous inoculation of 0.5 × 106 C. albicans blastospores. The treated animals were sacrificed on day 20, and 0.1 g of the tissue homogenates was plated onto specific media. In GC-Mass, the main components of the essential oil were carvacrol (61.29%) and thymol (25.18%). The results demonstrated that IP administration of 64 mg/kg of the essential oil had the highest efficacy in reducing C. albicans and produced 39.5, 21.8, 141.5, 174 and 501-fold reductions in mean CFUs per 0.1 gram in Candida infections of the liver, spleen, lungs, brain and kidneys, respectively, compared to positive control. Itraconazole showed significantly more responsiveness than the essential oil at dose of 30 mg/kg in clearing C. albicans from the kidneys (P<0.02), brain (P<0.02) and spleen (P<0.04), and less responsiveness than that of 64 mg/kg in clearing the organism from the brain (P<0.01), lungs (P<0.0005) and kidneys (P<0.0005), whereas no significant difference was observed between this drug and Z. multiflora at dose of 48 mg/kg. These data explain the increased rate of yeast clearance and reduced dissemination to the viscera of Z. multiflora treated mice. PMID:24031384

Potential use of tea extract as a complementary mouthwash: comparative evaluation of two commercial samples.

PubMed

Esimone, C O; Adikwu, M U; Nwafor, S V; Okolo, C O

2001-10-01

To evaluate the potential of using tea extracts as complementary mouthwash and to test the comparative efficacy of two commercial samples. A randomized controlled trial with 30 healthy human volunteers was carried out. The subjects were randomly assigned to 5 groups of 6 subjects per group. The ability of Ndu tea (from Cameroon) and Lipton tea (from Nigeria) to reduce colony forming units (CFU) in the liquid expectorated after 60 seconds of gargling from the mouth of the volunteers at 5 and 60 minutes were evaluated. These were compared to the values obtained from bank water and Minty Brett (thymol 0.047%), a standard antiseptic. University of Nigeria, Nsukka, Enugu State, Nigeria. Thirty healthy human volunteers (18 males and 12 females, between 22-30 years of age) who met the eligibility requirement of being nonsmokers and not taking any other antimicrobial agent were selected for the study. Relative to the bank water, the results indicated that the hot water extract of both teas significantly (p < 0.05) reduced CFU per milliliter in the liquid expectorated after gargling at both 5 and 60 minutes. Minty Brett showed higher activity than both tea extracts; however, unlike Minty Brett both extracts still reduced the CFU per milliliter at time 60 minutes (an indication of longer duration of activity). The combination of the tea extracts with sodium lauryl sulfate (1.2% w/v), a surfactant and emulsifier, significantly increased the antimicrobial activity relative to each tea alone. Comparatively, the activity of Ndu tea was found to be slightly higher than that of Lipton tea but this was not significant (p < 0.05). Lipton and Ndu tea extracts potently reduced the CFU per milliliter. This activity was potentiated by sodium lauryl sulfate. Although Minty Brett had more potent antimicrobial activity, both tea extracts have longer duration of activity. The results indicate the potential usefulness of tea extracts as a complementary mouthwash.

Unravelling the effects of mobile phase additives in supercritical fluid chromatography. Part I: Polarity and acidity of the mobile phase.

PubMed

West, Caroline; Melin, Jodie; Ansouri, Hassna; Mengue Metogo, Maïly

2017-04-07

The mobile phases employed in current supercritical fluid chromatography (SFC) are usually composed of a mixture of pressurized carbon dioxide and a co-solvent. The co-solvent is most often an alcohol and may contain a third component in small proportions, called an additive (acid, base or salt). The polarity of such mobile phase compositions is here re-evaluated with a solvatochromic dye (Nile Red), particularly to assess the contribution of additives. It appears that additives, when employed in usual concentration range (0.1% or 20mM) do not modify the polarity in the immediate environment of the probe. In addition, the combination of carbon dioxide and an alcohol is known to form alkoxylcarbonic acid, supposedly conferring some acidic character to SFC mobile phases. Direct measurements of the apparent pH are impossible, but colour indicators of pH can be used to define the range of apparent pH provided by carbon dioxide-alcohol mixtures, with or without additives. Five colour indicators (Thymol Blue, Bromocresol Green, Methyl Red, Bromocresol Purple, and Bromothymol Blue) were selected to provide a wide range of aqueous pK a values (from 1.7 to 8.9). UV-vis absorption spectra measured in liquid phases of controlled pH were compared to those measured with a diode-array detector employed in SFC, with the help of chemometric methods. Based on these observations, it is concluded that the apparent pH range in carbon dioxide-methanol mobile phases is close to 5. Increasing the proportion of methanol (in the course of a gradient elution for instance) causes decreasing apparent pH. Strong acids can further decrease the apparent pH below 1.7; strong bases have little influence on the apparent pH, probably because, in this range of concentrations, they are titrated by alkoxylcarbonic acid or form ion pairs with alkoxycarbonate. However, bases and salts could stabilize the acidity in the course of gradient runs. Copyright © 2017 Elsevier B.V. All rights reserved.

In vitro antibacterial, antifungal, and antioxidant activities of the essential oil and methanol extracts of herbal parts and callus cultures of Satureja hortensis L.

PubMed

Güllüce, M; Sökmen, M; Daferera, D; Ağar, G; Ozkan, H; Kartal, N; Polissiou, M; Sökmen, A; Sahin, F

2003-07-02

The present study was designated to evaluate the antimicrobial and antioxidant activities of the essential oil, obtained by using a Clevenger distillation apparatus, water soluble (polar) and water insoluble (nonpolar) subfractions of the methanol extracts from aerial parts of Satureja hortensis L. plants, and methanol extract from calli established from the seeds using Gamborg's B5 basal media supplemented with indole-3-butyric acid (1.0 ppm), 6-benzylaminopurine (N(6)-benzyladenine) (1.0 ppm), and sucrose (2.5%). The antimicrobial test results showed that the essential oil of S. hortensis had great potential antimicrobial activities against all 23 bacteria and 15 fungi and yeast species tested. In contrast, the methanol extract from callus cultures and water soluble subfraction of the methanol extract did not show antimicrobial activities, but the nonpolar subfraction had antibacterial activity against only five out of 23 bacterial species, which were Bacillus subtilis, Enterococcus fecalis, Pseudomonas aeruginosa, Salmonella enteritidis, and Streptococcus pyogenes. Antioxidant studies suggested that the polar subfractions of the methanol extract of intact plant and methanol extract of callus cultures were able to reduce the stable free radical 2,2-diphenyl-1-picrylhydrazyl to the yellow-colored diphenylpicrylhydrazine. In this assay, the strongest effect was observed for the tissue culture extract, with an IC(50) value of 23.76 +/- 0.80 microgram/mL, which could be compared with the synthetic antioxidant agent butylated hydroxytoluene. On the other hand, linoleic acid oxidation was 95% inhibited in the presence of the essential oil while the inhibition was 90% with the chloroform subfraction of the intact plant. The chemical composition of a hydrodistilled essential oil of S. hortensis was analyzed by gas chromatography (GC)/flame ionization detection (FID) and a GC-mass spectrometry system. A total 22 constituents representing 99.9% of the essential oil were identified by GC-FID analaysis. Thymol (29.0%), carvacrol (26.5%), gamma-terpinene (22.6%), and p-cymene (9.3%) were the main components.

Evaluation of the analgesic and anti-inflammatory effects of the essential oil of Lippia gracilis leaves.

PubMed

Mendes, S S; Bomfim, R R; Jesus, H C R; Alves, P B; Blank, A F; Estevam, C S; Antoniolli, A R; Thomazzi, S M

2010-06-16

The aim of the present study is to investigate the antinociceptive, anti-inflammatory, and antioxidant activities of essential oil (EO) of Lippia gracilis Schauer (Verbenaceae) leaves to support the medicinal uses claimed by folklore practitioners in the caatinga region (semi-arid) of Northeastern Brazil. The chemical composition and antinociceptive and anti-inflammatory activities of the EO of Lippia gracilis leaves (50-200 mg/kg) were investigated. Antinociceptive activity of the EO was evaluated by writhing test. Anti-inflammatory activity of the EO was evaluated using paw oedema and peritonitis methods. Oral treatment with the EO of Lippia gracilis leaves elicited inhibitory activity on acetic acid effect at 50, 100, and 200 mg/kg (30.33+/-2.36, 25.20+/-1.48, and 21.00+/-1.54 abdominal writhes, respectively, P<0.05), as compared with the control group (36.73+/-1.92 writhes). The compound acetylsalicylic acid (ASA, 300 mg/kg) inhibited the acetic acid-induced writhing (12.67+/-0.50 abdominal writhes, P<0.001). Carrageenan-induced oedema formation was reduced with the EO of Lippia gracilis leaves at 200 mg/kg (0.72+/-0.06 mL h, P<0.001) and by the reference compound ASA (300 mg/kg, 0.85+/-0.04 mL h, P<0.001), as compared with the control group (1.76+/-0.06 mL h). Leukocyte migration into the peritoneal cavity induced by carrageenan was reduced with the EO of Lippia gracilis leaves at 50, 100, and 200 mg/kg (13.81+/-0.61, 11.77+/-0.91, and 10.30+/-0.60 leukocytes x 10(6)/mL, respectively, P<0.01), and by the compound dexamethasone (2 mg/kg, 5.34+/-0.33 leukocytes x 10(6)/mL, P<0.001), as compared with the control group (16.71+/-0.54 leukocytes x 10(6)/mL). The analyses of the essential oil allowed the identification of Lippia gracilis as a thymol-p-cymene chemotype (32.68% and 17.82%, respectively). The EO of Lippia gracilis leaves shows antinociceptive and anti-inflammatory activities. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Impact of dietary organic acids and botanicals on intestinal integrity and inflammation in weaned pigs.

PubMed

Grilli, Ester; Tugnoli, Benedetta; Passey, Jade L; Stahl, Chad H; Piva, Andrea; Moeser, Adam J

2015-04-16

Organic acids, such as citric and sorbic acid, and pure plant-derived constituents, like monoterpens and aldehydes, have a long history of use in pig feeding as alternatives to antibiotic growth promoters. However, their effects on the intestinal barrier function and inflammation have never been investigated. Therefore, aim of this study was to assess the impact of a microencapsulated mixture of citric acid and sorbic acid (OA) and pure botanicals, namely thymol and vanillin, (PB) on the intestinal integrity and functionality of weaned pigs and in vitro on Caco-2 cells. In the first study 20 piglets were divided in 2 groups and received either a basal diet or the basal diet supplemented with OA + PB (5 g/kg) for 2 weeks post-weaning at the end of which ileum and jejunum samples were collected for Ussing chambers analysis of trans-epithelial electrical resistance (TER), intermittent short-circuit current (I SC), and dextran flux. Scrapings of ileum mucosa were also collected for cytokine analysis (n = 6). In the second study we measured the effect of these compounds directly on TER and permeability of Caco-2 monolayers treated with either 0.2 or 1 g/l of OA + PB. Pigs fed with OA + PB tended to have reduced I SC in the ileum (P = 0.07) and the ileal gene expression of IL-12, TGF-β, and IL-6 was down regulated. In the in vitro study on Caco-2 cells, TER was increased by the supplementation of 0.2 g/l at 4, 6, and 14 days of the experiment, whereas 1 g/l increased TER at 10 and 12 days of treatment (P < 0.05). Dextran flux was not significantly affected though a decrease was observed at 7 and 14 days (P = 0.10 and P = 0.09, respectively). Overall, considering the results from both experiments, OA + PB improved the maturation of the intestinal mucosa by modulating the local and systemic inflammatory pressure ultimately resulting in a less permeable intestine, and eventually improving the growth of piglets prematurely weaned.

Effect of various commercially available mouthrinses on shear bond strength of orthodontic metal brackets: an in vitro study.

PubMed

Meeran, Nazeer Ahmed; George, Ashwin Mathew

2013-01-01

Alcohol is known to degrade and dissolve the bisphenol A glycidyl methacrylate present in the composite resin. The effect of alcohol containing mouthrinses on the shear bond strength of orthodontic metal brackets bonded with composite resin has not been verified until date and is the purpose of this study. The aims and objectives of the present study were to evaluate (1) Whether there is a significant difference in the shear bond strength of metal orthodontic brackets after the 1 year (12 h) and 2 years simulation (24 h) of mouth rinsing with 4 different commercially available mouthrinses (2 alcoholic and 2 alcohol-free mouthrinses) when compared to the control. (2) Whether alcohol containing mouthrinses have more adverse effect on the shear bond strength when compared with alcohol-free mouthrinses. (3) To assess the site of bond failure using adhesive remnant index. Experimental - laboratory based. A total of 100 upper premolars extracted for orthodontic purpose were collected immediately after extraction, cleared soft-tissue debris and blood and immediately stored in distilled water with 0.1% thymol crystals added to inhibit bacterial growth. Two alcohol containing mouthrinses and two alcohol-free mouthrinses were used and the bonded teeth were placed in the mouthrinses for a stipulated period of time (1 year simulation and 2 years simulation) and shear bond strength were tested using Lloyd Universal Testing Machine. The data were analyzed using analysis of variance and paired samples t-test. After the 1 year and 2 years simulation time, samples stored in alcohol containing mouthrinses showed lower bond strength (P < 0.05) when compared to samples stored in alcohol free mouthrinses and distilled water (control). Alcohol containing mouthrinses affect the shear bond strength of the metal orthodontic brackets bonded with composite resin (Transbond XT in the present study), more when compared with alcohol-free mouthrinses. It is, therefore, highly advisable to avoid alcohol containing mouthrinses in patients undergoing orthodontic treatment and use alcohol-free mouthrinses as adjuncts to regular oral hygiene procedures for maintaining good enamel integrity and periodontal health, without compromising the shear bond strength of the bonded metal brackets.

Pulp chamber temperature rise during curing of resin-based composites with different light-curing units.

PubMed

Durey, Kathryn; Santini, Ario; Miletic, Vesna

2008-01-01

The purpose of the present study was to measure the intrapulpal temperature rise occurring during polymerisation of different shades of resin-based composites (RBCs), and two light-emitting diode (LED) units. Seventy non-carious permanent molars, that had been extracted for orthodontic purposes and stored in 2% thymol for not more than four months, were selected. Patient age range was 11-18 years. Standard cavity preparation with standardised remaining dentine thickness and placement of thermocouples (TCs) was prepared using a novel split-tooth technique. Cavities were filled with one of two shades of RBC (A2 and C4, Filtek Z250, 3M ESPE, Seefeld, Germany), and cured with two LED high-intensity units (Elipar Freelight2, 3M ESPE, Seefeld, Germany; Bluephase, Ivoclar Vivadent, Schaan, Liechtenstein) and a conventional halogen light-curing unit (LCU) (Prismetics Lite 2, Dentsply, Weybridge, Surrey, UK) as a control. Pulp temperature rises during bonding [A2 results: H;2.67/0.48:E;5.24/1.32;B;5.99/1.61] were always greater than during RBC curing [A2 results: 2.44/0.63;E3.34/0.70;B3.38/0.60], and these were significant for both LED lights but not for the halogen control, irrespective of shade (Mann-Whitney test: 95% confidence limits). Temperature rises were at times in excess of the values normally quoted as causing irreversible pulp damage. Pulp temperature rises during bonding were higher with the LED lights than with the halogen control. There was no significant difference in temperature rise between the two LED lights when bonding but there was a significant difference between the two LED lights and the halogen control LCUs (Kruskal-Wallis Test: 95% confidence limits). The results support the view that there is a potential risk for heat-induced pulpal injury when light-curing RBCs. The risk is greater during bonding and with high energy, as compared to low-energy output systems. As the extent of tolerable thermal trauma by the pulp tissues is unknown, care and consideration should be given to the choice of LCU and the exposure time when curing RBCs, and especially during bonding.

Combined Tin-Containing Fluoride Solution and CO2 Laser Treatment Reduces Enamel Erosion in vitro.

PubMed

Esteves-Oliveira, Marcella; Witulski, Nadine; Hilgers, Ralf-Dieter; Apel, Christian; Meyer-Lueckel, Hendrik; Eduardo, Carlos de Paula

2015-01-01

The aim of this in vitro study was to evaluate the effect of combined CO2 laser and tin-containing fluoride treatment on the formation and progression of enamel erosive lesions. Ninety-six human enamel samples were obtained, stored in thymol solution and, after surface polishing, randomly divided into 6 different surface treatment groups (n = 16 in each group) as follows: no treatment, control (C); one CO2 laser irradiation (L1); two CO2 laser irradiations (L2); daily application of fluoride solution (F); combined daily fluoride solution + one CO2 laser irradiation (L1F), and combined daily fluoride solution + two CO2 laser irradiations (L2F). Laser irradiation was performed at 0.3 J/cm2 (5 µs/226 Hz/10.6 µm) on day 1 (L1) and day 6 (L2). The fluoride solution contained AmF/NaF (500 ppm F), and SnCl2 (800 ppm Sn) at pH 4.5. After surface treatment the samples were submitted to an erosive cycling over 10 days, including immersion in citric acid (2 min/0.05 M/pH = 2.3) 6 times daily and storage in remineralization solution (≥1 h) between erosive attacks. At the end of each cycling day, the enamel surface loss (micrometers) was measured using a 3D laser profilometer. Data were statistically analyzed by means of a 2-level mixed effects model and linear contrasts (α = 0.05). Group F (-3.3 ± 2.0 µm) showed significantly lower enamel surface loss than groups C (-27.22 ± 4.1 µm), L1 (-18.3 ± 4.4 µm) and L2 (-16.3 ± 5.3 µm) but higher than L1F (-1.0 ± 4.4 µm) and L2F (1.4 ± 3.2 µm, p < 0.05). Under the conditions of this in vitro study, the tin-containing fluoride solution caused 88% reduction of enamel surface loss, while its combination with CO2 laser irradiation at 0.3 J/cm2 hampered erosive loss almost completely. © 2015 S. Karger AG, Basel.

Elucidation of mechanisms of actions of thymoquinone-enriched methanolic and volatile oil extracts from Nigella sativa against cardiovascular risk parameters in experimental hyperlipidemia.

PubMed

Ahmad, Shafeeque; Beg, Zafarul H

2013-06-13

Nigella sativa belonging to the Ranunculaceae family has been reported to use for thousands of years as protective and curative traditional medicine against a number of diseases. GC-MS analysis of methanolic extract (ME) and volatile oil (VO) extracted from Nigella sativa seed oil was performed by two different mass spectrometry libraries, WIlEY8 and NIST05s. The cholesterol lowering and antioxidant actions of VO and ME fractions were investigated in atherogenic suspension fed rats. In this study, four groups of male Wistar rats were used: normolipidemic control (NLP-C), hyperlipidemic control (HLP-C), methanolic extract (HLP-ME) and volatile oil treated (HLP-VO) groups for 30 days of duration. P value < 0.05 was assumed as significant data in groups. Administration of atherogenic suspension to male Wistar rats for 30 days resulted in a marked increase of plasma triglycerides and total cholesterol, and significant change in plasma lipoprotein levels along with a decrease in antioxidant arylesterase activity in hyperlipidemic control (HLP-C) group. The oral feeding of 100 mg ME or 20 mg VO per rat/day effectively reduced the plasma triglycerides to near normal level, while high density lipoprotein cholesterol and its subfraction along with arylesterase activity levels were significantly increased. The test fractions elicited a significant decrease in hepatic HMG-CoA reductase activity. The fractions significantly blocked the ex vivo basal and in vitro maximal formation of conjugated diene and malondialdehyde, and lengthened the lag times of low density lipoprotein, small dense low density lipoprotein and large buoyant low density lipoprotein. ME possessing ω-6 linoleic acid along with palmitic acid active compounds was more effective than VO extract containing thymol and isothymol phenolic antioxidant compounds, thymoquinone phenolic compound common to the both extracts, via reduction in hepatic HMG-CoA reductase activity as well as antioxidant mechanisms. The both extracts especially, ME significantly improve cardiovascular risk parameters in treated rats, and can be used in reactive oxygen species disorders such as cardiovascular diseases.

Chemical Composition, Antioxidant, Anti-Inflammatory and Anti-Proliferative Activities of Essential Oils of Plants from Burkina Faso

PubMed Central

Bayala, Bagora; Bassole, Imaël Henri Nestor; Gnoula, Charlemagne; Nebie, Roger; Yonli, Albert; Morel, Laurent; Figueredo, Gilles; Nikiema, Jean-Baptiste; Lobaccaro, Jean-Marc A.; Simpore, Jacques

2014-01-01

This research highlights the chemical composition, antioxidant, anti-inflammatory and anti-proliferative activities of essential oils from leaves of Ocimum basilicum, Ocimum americanum, Hyptis spicigera, Lippia multiflora, Ageratum conyzoides, Eucalyptus camaldulensis and Zingiber officinale. Essential oils were analyzed by gas chromatography–mass spectrometry and gas chromatography–flame ionization detector. Major constituents were α-terpineol (59.78%) and β-caryophyllene (10.54%) for Ocimum basilicum; 1, 8-cineol (31.22%), camphor (12.730%), α-pinene (6.87%) and trans α-bergamotene (5.32%) for Ocimum americanum; β-caryophyllene (21%), α-pinene (20.11%), sabinene (10.26%), β-pinene (9.22%) and α-phellandrene (7.03%) for Hyptis spicigera; p-cymene (25.27%), β-caryophyllene (12.70%), thymol (11.88), γ-terpinene (9.17%) and thymyle acetate (7.64%) for Lippia multiflora; precocene (82.10%)for Ageratum conyzoides; eucalyptol (59.55%), α-pinene (9.17%) and limonene (8.76%) for Eucalyptus camaldulensis; arcurcumene (16.67%), camphene (12.70%), zingiberene (8.40%), β-bisabolene (7.83%) and β-sesquiphellandrène (5.34%) for Zingiber officinale. Antioxidant activities were examined using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods. O. basilicum and L. multiflora exhibited the highest antioxidant activity in DPPH and ABTS tests, respectively. Anti-inflammatory properties were evaluated by measuring the inhibition of lipoxygenase activity and essential oil of Z. officinale was the most active. Anti-proliferative effect was assayed by the measurement of MTT on LNCaP and PC-3 prostate cancer cell lines, and SF-763 and SF-767 glioblastoma cell lines. Essential oils from A. conyzoides and L. multiflora were the most active on LNCaP and PC-3 cell lines, respectively. The SF-767 glioblastoma cell line was the most sensitive to O. basilicum and L. multiflora EOs while essential oil of A. conyzoides showed the highest activity on SF-763 cells. Altogether these results justify the use of these plants in traditional medicine in Burkina Faso and open a new field of investigation in the characterization of the molecules involved in anti-proliferative processes. PMID:24662935

Chemical composition, antioxidant, anti-inflammatory and anti-proliferative activities of essential oils of plants from Burkina Faso.

PubMed

Bayala, Bagora; Bassole, Imaël Henri Nestor; Gnoula, Charlemagne; Nebie, Roger; Yonli, Albert; Morel, Laurent; Figueredo, Gilles; Nikiema, Jean-Baptiste; Lobaccaro, Jean-Marc A; Simpore, Jacques

2014-01-01

This research highlights the chemical composition, antioxidant, anti-inflammatory and anti-proliferative activities of essential oils from leaves of Ocimum basilicum, Ocimum americanum, Hyptis spicigera, Lippia multiflora, Ageratum conyzoides, Eucalyptus camaldulensis and Zingiber officinale. Essential oils were analyzed by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. Major constituents were α-terpineol (59.78%) and β-caryophyllene (10.54%) for Ocimum basilicum; 1, 8-cineol (31.22%), camphor (12.730%), α-pinene (6.87%) and trans α-bergamotene (5.32%) for Ocimum americanum; β-caryophyllene (21%), α-pinene (20.11%), sabinene (10.26%), β-pinene (9.22%) and α-phellandrene (7.03%) for Hyptis spicigera; p-cymene (25.27%), β-caryophyllene (12.70%), thymol (11.88), γ-terpinene (9.17%) and thymyle acetate (7.64%) for Lippia multiflora; precocene (82.10%)for Ageratum conyzoides; eucalyptol (59.55%), α-pinene (9.17%) and limonene (8.76%) for Eucalyptus camaldulensis; arcurcumene (16.67%), camphene (12.70%), zingiberene (8.40%), β-bisabolene (7.83%) and β-sesquiphellandrène (5.34%) for Zingiber officinale. Antioxidant activities were examined using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods. O. basilicum and L. multiflora exhibited the highest antioxidant activity in DPPH and ABTS tests, respectively. Anti-inflammatory properties were evaluated by measuring the inhibition of lipoxygenase activity and essential oil of Z. officinale was the most active. Anti-proliferative effect was assayed by the measurement of MTT on LNCaP and PC-3 prostate cancer cell lines, and SF-763 and SF-767 glioblastoma cell lines. Essential oils from A. conyzoides and L. multiflora were the most active on LNCaP and PC-3 cell lines, respectively. The SF-767 glioblastoma cell line was the most sensitive to O. basilicum and L. multiflora EOs while essential oil of A. conyzoides showed the highest activity on SF-763 cells. Altogether these results justify the use of these plants in traditional medicine in Burkina Faso and open a new field of investigation in the characterization of the molecules involved in anti-proliferative processes.

In vitro and in vivo mechanism of immunomodulatory and antiviral activity of Edible Bird's Nest (EBN) against influenza A virus (IAV) infection.

PubMed

Haghani, Amin; Mehrbod, Parvaneh; Safi, Nikoo; Aminuddin, Nur Ain; Bahadoran, Azadeh; Omar, Abdul Rahman; Ideris, Aini

2016-06-05

For centuries, Edible Bird Nest (EBN) has been used in treatment of variety of respiratory diseases such as flu and cough as a Chinese natural medicine. This natural remedy showed the potential to inhibit influenza A virus (IAV). However, little is known about the mechanism of this process and also the evaluation of this product in an animal model. Hence, the current study was designed to elucidate the antiviral and immunomodulatory effects of EBN against IAV strain A/Puerto Rico/8/1934 (H1N1). First, influenza infected MDCK cells treated with EBNs from two locations of Malaysia (Teluk Intan and Gua Madai) that prepared with different enzymatic preparations were analyzed by RT-qPCR and ELISA for detection of viral and cytokines genes. The sialic acid composition of these EBNs was evaluated by H-NMR. Subsequently, after toxicity evaluation of EBN from Teluk Intan, antiviral and immunomodulatory effects of this natural product was evaluated in BALB/c mice by analysis of the viral NA gene and cytokine expressions in the first week of the infection. EBN showed high neuraminidase inhibitory properties in both in vitro and in vivo, which was as effective as Oseltamivir phosphate. In addition, EBN decreased NS1 copy number (p<0.05) of the virus along with high immunomodulatory effects against IAV. Some of the immune changes during treatment of IAV with EBN included significant increase in IFNγ, TNFα, NFκB, IL2, some proinflammatory cytokines like IL1β, IL6, and cytokines with regulatory properties like IL10, IL27, IL12, CCL2 and IL4 depends on the stage of the infection. EBNs from two locations contained different composition of sialic acid and thymol derivatives, which gave them different antiviral properties. EBN from Gua Madai that contained more acetylated sialic acid (Neu2,4,7,8,9 Ac6) showed higher antiviral activity. The findings of this study support the antiviral activity of EBN against influenza virus and validate the traditional usage of this natural remedy by elucidation of toxicity and the molecular mechanism of action. Copyright © 2016. Published by Elsevier Ireland Ltd.

The chemical composition and trypanocidal activity of volatile oils from Brazilian Caatinga plants.

PubMed

Oliveira de Souza, Larissa Isabela; Bezzera-Silva, Patrícia Cristina; do Amaral Ferraz Navarro, Daniela Maria; da Silva, Alexandre Gomes; Dos Santos Correia, Maria Tereza; da Silva, Márcia Vanusa; de Figueiredo, Regina Celia Bressan Queiroz

2017-12-01

Essential/volatile oils (EOs) from plants used in the traditional medicine are known as a rich source of chemically diverse compounds with relevant biological activities. In this work we analysed the chemical composition and the in vitro effects of EOs from leaves of Eugenia brejoensis (EBEO), Hyptis pectinata (HPEO), Hypenia salzmannii (HSEO), Lippia macrophylla (LMEO) and seeds of Syagrus coronata (SCEO) on Trypanosoma cruzi, the etiological agent of Chagas disease. The EOs were extracted through hydrodistillation and its chemical composition analysed by GC/MS. The trypanocidal activity against epi- and trypomastigotes was evaluated by optical microscopy and the cytotoxicity to mammalian cells by MTT. The effects of EOs on parasite infection in macrophages were estimated by determining the survival index and the percentage of infection inhibition. The cytotoxicity against mammalian cells was compared to those of parasite by determining the Selectivity Index (SI). Overall, 114 compounds were identified: The main constituents of EOS were: δ-cadinene (15.88%), trans-caryophyllene (9.77%) e α-Muurolol (9.42%) for EBEO; trans-caryophyllene (15.24%), bicyclogermacrene (7.33%) e cis-calamenene (7.15%) for HFEO; trans-caryophyllene (30.91%), caryophyllene oxide (13.19%) and spathulenol (5.68%) for HPEO; Xanthoxylin (17.20%) trans-caryophyllene (14.34%) and methyl-eugenol (5.60%) for HSEO; Thymol (49.81%), carvacrol (31.6%) and σ-cimene (10.27%) for LMEO and octanoic acid (38.83%) dodecanoic acid (38.45%) and decanoic acid (20.51%) for SCEO. All the tested oils showed an inhibitory effect on the growth and survival of all forms of T. cruzi and moderate cytotoxicity towards the mammalian cells (100 < CC 50  < 500 μg/mL). The EO of E. brejoensis was the most effective against the parasite presenting higher Selectivity Index for trypo- (SI = 14.45) and amastigote forms (SI = 20.11). Except for SCEO, which was the most cytotoxic for both parasite and mammalian cells, all the oils demonstrated to be more selective for the parasite than the reference drug benznidazole. Taken together our results point the essential oils from Caatinga plants, especially Eugenia brejoensis, as promissory agents for the development of new drugs against Chagas disease. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Effects of limonene on ruminal concentrations, fermentation, and lysine degradation in cattle.

PubMed

Samii, S Saed; Wallace, N; Nagaraja, T G; Engstrom, M A; Miesner, M D; Armendariz, C K; Titgemeyer, E C

2016-08-01

Previous in vitro data showed that was inhibited by limonene. We further evaluated effects of limonene on growth of in vitro as well as on ruminal concentrations of in vivo. With in vitro cultivation in anaerobic brain-heart infusion broth, limonene decreased growth of . Thymol also reduced growth of , but it was less effective than limonene. Tylosin effectively reduced growth of in vitro. Although the response over fermentation times and concentrations of antimicrobials differed somewhat between tylosin and limonene, the 2 antimicrobial agents yielded similar inhibitory effects on growth of at concentrations ranging from 6 to 24 mg/L. The effects of limonene on ruminal concentration in vivo were tested in 7 ruminally cannulated heifers (225 kg initial BW) used in a 7 × 4 Youden square design. Treatments included: 1) control, 2) limonene at 10 mg/kg diet DM, 3) limonene at 20 mg/kg diet DM, 4) limonene at 40 mg/kg diet DM, 5) limonene at 80 mg/kg diet DM, 6) CRINA-L (a blend of essential oil components) at 180 mg/kg diet DM, and 7) tylosin at 12 mg/kg diet DM. Each period included 11 d with 10 d washouts between periods. Samples of ruminal contents were collected before treatment initiation and after 4, 7, and 10 d of treatment for measuring by the most probable number method using selective culture medium. Limonene linearly decreased ( = 0.03) ruminal concentration, with the lowest concentration achieved with 40 mg of limonene/kg dietary DM. Limonene tended ( ≤ 0.07) to linearly reduce ruminal molar proportions of propionate and valerate while tending to linearly increase ( ≤ 0.10) those of butyrate and 2-methyl butyrate. Limonene did not affect ruminal NH concentrations or degradation rates of lysine. Neither CRINA-L ( = 0.52) nor tylosin ( = 0.19) affected ruminal concentrations. CRINA-L significantly decreased ruminal concentrations of NH and molar proportions of 3-methyl butyrate, whereas tylosin significantly decreased molar proportions of propionate while increasing those of butyrate and tending to increase those of acetate. Limonene supplementation reduced ruminal concentrations of suggesting that it may have the potential to reduce the prevalence of liver abscesses, although further research is needed to assess the effect of limonene in feedlot cattle.

Effects of organic acids and essential oils blend on growth, gut microbiota, immune response and disease resistance of Pacific white shrimp (Litopenaeus vannamei) against Vibrio parahaemolyticus.

PubMed

He, Wangquan; Rahimnejad, Samad; Wang, Ling; Song, Kai; Lu, Kangle; Zhang, Chunxiao

2017-11-01

An 8-week feeding trial was undertaken to evaluate supplemental effects of AviPlus ® (AP), a blend of organic acids [citric acid, 25%; sorbic acid, 16.7%] and essential oils [thymol, 1.7%; vanillin, 1.0%], on growth, gut microbiota, innate immunity and disease resistance of Pacific white shrimp (Litopenaeus vannamei) against Vibrio parahaemolyticus. A basal experimental diet was formulated and supplemented with 0, 0.3, 0.6, 0.9 and 1.2 g kg -1  AP to produce five test diets (Con, AP0.3, AP0.6, AP0.9 and AP1.2). Each diet was fed to triplicate groups of shrimp (0.2 ± 0.01 g, mean ± SE) to apparent satiation three times daily. Growth performance and survival rate were not significantly influenced by AP supplementation (P > 0.05). Significantly (P < 0.05) higher serum total protein was found in groups fed ≥ 0.6 g kg -1  AP compared to control. Serum alkaline phosphatase and phenoloxidase activities were significantly increased in AP0.9 and AP1.2 groups. Also, the group received AP0.6 diet showed significantly higher glutathione peroxidase activity than control. Expression of gut pro-inflammatory genes including TNF-α, LITAF and RAB6A were down-regulated by AP administration. Gut microbiota analysis showed the significant enhancement of the operational taxonomic unit (OTU) diversity and richness indices by AP application. AP supplementation led to increased abundance of Firmicutes and a reduction in abundance of Proteobacteria. Also, dietary inclusion of 1.2 g kg -1  AP led to a significant increase in the abundance of Lactobacillus in shrimp gut. The group offered AP0.3 diet showed significantly higher disease resistance than control group. Furthermore, AP application significantly enhanced relative expression of immune related genes including lysozyme, penaeidin and catalase at 48 h post challenge. In conclusion, these findings show that the tested organic acids and essential oils mixture beneficially affects intestinal microflora and improves immune response and disease resistance of L. vannamei. Copyright © 2017 Elsevier Ltd. All rights reserved.

Could essential oils enhance biopolymers performance for wound healing? A systematic review.

PubMed

Pérez-Recalde, Mercedes; Ruiz Arias, Ignacio E; Hermida, Élida B

2018-01-01

Millions of people in the world suffer from chronic wounds of different etiologies such as diabetic foot and leg ulcers, without solutions nowadays. Molecules obtained from plants offer an alternative to aid wound healing. Strong evidence about essential oils (EO) anti-inflammatory and antimicrobial properties is thoroughly described in literature and their chemical compositions are well characterized. More recently, EO effects in experimental wounds have begun to be analyzed. We aim to summarize the evidence of EO in experimental wounds, and the possibility of combining them with biopolymers commonly used in skin regeneration. Electronic databases such as ScienceDirect, PubMed and Scopus were used to search scientific contributions until March 2017, using relevant keywords. In a first step, literature focusing on EO and/or mono- or sesqui-terpenoids effects in rodent wounds was identified and summarized. In all cases, chemical structures and EO composition were detailed, as well as references to in vitro activities previously determined, e.g. antibacterial, antioxidant or anti-inflammatory. In a second step, scientific literature devoted to combine EO and biopolymers with the focus set on wound healing innovations, was collected and analyzed. Treatments with EO from species of genders Lavandula, Croton, Blumea, Eucalyptus, Pinus, Cymbopogon, Eucalyptus, Cedrus, Abies, Rosmarinus, Origanum, Salvia and Plectranthus, have shown positive results in rodent wounds. All of these EO were mainly composed by monoterpenoids-thymol, 1,8-cineole, linalool-or monoterpenes, as limonene or pinenes. Experimental wounds in rodents have shown faster closure rate, better collagen deposition and/or enhanced fibroblasts proliferation. In blends with biopolymers, several EO combined with chitosan, alginate, gelatin or collagen, were processed to give active films or nanofibers, with antioxidant, anti-inflammatory or antimicrobial activities. Curiously, all of these works were carried out since 2010. There is significant evidence about the effectivity of EO as wound healers. The incorporation of EO into a polymer matrix that contributes to wound healing is still incipient. However, scientific based evidence of the EO incorporation in resorbable polymeric scaffolds was found and analyzed herein. In summary, EO-biopolymer dressings or scaffolds have become promising artifacts regarding wound treatments, especially in chronic wounds, where treating infection and inflammation are still important issues. Copyright © 2017 Elsevier GmbH. All rights reserved.

Salmonella and Escherichia coli O157:H7 Inactivation, Color, and Bioactive Compounds Enhancement on Raspberries during Frozen Storage after Decontamination Using New Formula Sanitizer Washing or Pulsed Light.

PubMed

Xu, Wenqing; Chen, Haiqiang; Wu, Changqing

2016-07-01

Berries are normally washed before they are frozen. Washing with sanitizer and treatment with pulsed light (PL) were studied for their effectiveness to inactivate foodborne pathogens on raspberries during frozen storage, while maintaining or enhancing major quality parameters. Raspberries were inoculated with Salmonella or Escherichia coli O157:H7 and then underwent a washing treatment with citric acid plus sodium dodecyl sulfate (CA+SDS) or citric acid plus thymol (CA+THY) or treatment with PL (dry PL, water-assisted [wet] PL, and PL-SDS). Pathogen survival was determined immediately after treatments and during frozen storage at -20°C for 3 months. Washing with CA+SDS or CA+THY significantly reduced Salmonella (by 3.6 and 3.2 log CFU/g, respectively) and E. coli O157:H7 (by 4.1 and 3.7 log CFU/g, respectively). At the end of storage, washing with CA+SDS reduced Salmonella to 0.6 log CFU/g and E. coli O157:H7 to 0.5 log CFU/g; washing with CA+THY reduced Salmonella to 0.9 log CFU/g and E. coli O157:H7 to 0.5 log CFU/g. PL-SDS showed decontamination efficacy on raspberries, with 0.7 log CFU/g Salmonella and 0.9 log CFU/g E. coli O157:H7 surviving at the end of storage; in comparison, in the control, 1.6 log CFU/g Salmonella and 1.5 log CFU/g E. coli O157:H7 survived. Pathogen survival in raspberries that had been washed or treated with PL-SDS was significantly lower than in untreated raspberries. Major quality parameters, including color, total phenolic content, total anthocyanin content, total bacterial count, and total yeast and mold counts, were evaluated on raspberries immediately after treatments and during frozen storage. Redness increased in PL-treated raspberries. At the end of storage, PL-treated raspberries had significantly higher total phenolic content and total anthocyanin content compared with control samples. Washing with sanitizers and treatment with PL decreased the total bacterial count and total yeast and mold counts on raspberries and maintained the low counts. Our findings suggest that washing with a sanitizer or treatment with PL could be used to process frozen raspberries for enhanced food safety and quality.

Effect of saliva contamination on the microshear bond strength of one-step self-etching adhesive systems to dentin.

PubMed

Yoo, H M; Oh, T S; Pereira, P N R

2006-01-01

This study evaluated the effect of saliva contamination and decontamination methods on the dentin bond strength of one-step self-etching adhesive systems. Three commercially available "all-in-one" adhesives (One Up Bond F, Xeno III and Adper Prompt) and one resin composite (Filtek Z-250) were used. Third molars stored in distilled water with 0.5% thymol at 4 degrees C were ground with #600 SiC paper under running water to produce a standardized smear layer. The specimens were randomly divided into groups according to contamination methods: no contamination, which was the control (C); contamination of the adhesive surface with fresh saliva before light curing (A) and contamination of the adhesive surface with fresh saliva after light curing (B). Each contamination group was further subdivided into three subgroups according to the decontamination method: A1-Saliva was removed by a gentle air blast and the adhesive was light-cured; A2-Saliva was rinsed for 10 seconds, gently air-dried and the was adhesive light-cured; A3-Saliva was rinsed and dried as in A2, then the adhesive was re-applied to the dentin surface and light-cured; B1-Saliva was removed with a gentle air blast; B2-Saliva was rinsed and dried; B3-Saliva was rinsed, dried and the adhesive was re-applied and light cured. Tygon tubes filled with resin composite were placed on each surface and light cured. All specimens were stored in distilled water at 37 degrees C for 24 hours. Microshear bond strength was measured using a universal testing machine (EZ test), and data were analyzed by one-way ANOVA followed by the Duncan test to make comparisons among the groups (p<0.05). After debonding, five specimens were selected and examined in a scanning electron microscope to evaluate the modes of fracture. The A2 subgroup resulted in the lowest bond strength. For One Up Bond F and Adper Prompt, there was no significant difference between subgroup A1 and the control, and subgroup A3 and the control (p>0.05). Bond strengths of all B groups were significantly lower compared to the controls (p<0.05). For Xeno III, A1 subgroup showed the greatest decrease in bond strength as compared to the control (p<0.05). On the other hand, it showed more resistance to salivary contamination after adhesive curing. There was no statistically significant difference among the control groups (p>0.05).

Convection induced by selective absorption of radiation: A laboratory model of conditional instability

NASA Astrophysics Data System (ADS)

Krishnamurti, Ruby

1998-01-01

When there is internal heating in a fluid layer, convection can occur even if the static state is one of stable stratification. We have been investigating through laboratory experiments such a stably stratified layer of water which is heated above and cooled below. The water contains in dilute solution thymol blue (a pH indicator), which normally colors the water orange. It turns yellow if the pH is low, blue if the pH is high. A small DC voltage is applied across the layer, by using the bottom boundary as the positive electrode, the top boundary as the negative electrode. The hydroxyl ions formed near the bottom boundary cause the orange fluid to turn blue. The fluid layer is uniformly and steadily illuminated from above with light from a sodium vapor lamp. This radiation travels with negligible absorption through the orange fluid but is strongly absorbed by the blue fluid. The resultant warming of the blue fluid can lead to convective instability, with the blue fluid rising into warm upper layers, which it would continue to penetrate as long as it remains blue and as long as the radiative heating is sufficient to exceed the higher ambient temperatures above. This radiative heating occurs only in the blue rising flow; the sinking fluid is orange and is not heated. We have found that with a strongly stably stratified layer, convective plumes are unable to penetrate far and they remain shallow. However, for a weakly stratified layer, plumes grow tall and furthermore collect into a large convective cluster which persists as a steady coherent structure. The present paper deals also with the formulation of the governing equations to include the fluid-state-dependent heat source. A linear stability analysis shows that the critical Rayleigh number for onset of motion is drastically reduced. Furthermore, the cell size at onset is larger by a factor of √ 3/2 than in the classical Rayleigh-Benard convection problem. However, the laboratory fluid cells were much further broadened (by a factor of 8 or 10) when they penetrated into the stably stratified fluid above. In this case, the rising region is narrow and the sinking region is broad, so that downward vertical velocities are correspondingly small. In this way, the downwards-forced warm fluid has time to cool by conduction to the cold boundary. Steady finite amplitude solutions and their stability are analyzed and it is shown that there is a parameter range in which finite amplitude hexagonal cells are stable.

Virulence factors and antimicrobial resistance in Escherichia coli strains isolated from hen egg shells.

PubMed

Grande Burgos, María José; Fernández Márquez, Maria Luisa; Pérez Pulido, Rubén; Gálvez, Antonio; Lucas López, Rosario

2016-12-05

Eggs may contain extraintestinal pathogenic (ExPEC) and diarrheogenic (DEC) Escherichia coli which in addition may carry antibiotic resistance. The wide use of biocides and disinfectants in the food industry may induce biocide tolerance in bacteria. The aim of the present study was to evaluate biocide tolerance and antibiotic resistance in E. coli from hen egg shells. A total of 27 isolates obtained from a screening of 180 eggs were studied. Seven isolates carried both eae and bfpA genes of typical enteropathogenic E. coli (EPEC) strains, while 14 isolates only carried eae associated with atypical EPEC strains. Shiga toxin genes stx and stx2 were detected in four isolates. Heat-stable and heat-labile enterotoxin genes as well as aggR were also detected. Several isolates had minimum inhibitory concentrations (MICs) that were higher than the wild-type for the biocide hexadecylpyridinium chloride (HDP, 18.52%) or the commercial disinfectant P3 oxonia (OX, 14.81%). Antibiotic resistance was detected for ampicillin (37.03%), streptomycin (37.03%), tetracycline (37.03%), chloramphenicol (11.11%), nalidixic acid (18.51%) and trimethoprim-sulfamethoxazole (14.81%). Eight isolates (29.63%) were biocide tolerant and antibiotic resistant. Efflux pump genes detected included acrB (96.29%), mdfA (85.18%) and oxqA (37.03%), in addition to quaternary ammonium compound (QAC) resistance genes qacA/B (11.11%) and qacE (7.40%). Antibiotic resistance genes detected included bla CTX-M-2 (22.22%), bla TEM (3.70%), bla PSE (3.70%), tet(A) (29.63%), tet(B) (29.63%), tet(C) (7.40%), tet(E) (11.11%), aac(6')-Ib (3.70%), sul1 (14.81%), dfrA12 (3.70%) and dfrA15 (3.70%). Most isolates (96.30%) carried more than one genetic determinant of resistance. The most frequent combinations were efflux pump components acrB and mdfA with tetracycline resistance genes (33.33% of isolates). Isolates carrying QAC resistance genes also carried between 4 and 8 of the additional antimicrobial resistance genes investigated. Regardless of biocide tolerance and antibiotic resistance, all isolates were sensitive to carvacrol (0.25%), thymol (0.125%) and trisodium phosphate (1 to 1.5%), but they exhibited a heterogeneous response to sodium lactate and lysozyme-EDTA combinations that apparently were not related with antibiotic resistance. Results from the study reveal not only a low incidence of biocide tolerance but also the presence of multiple resistance strains carrying multiple genetic determinants of resistance. Copyright © 2016 Elsevier B.V. All rights reserved.

Similar increases in extracellular lactic acid in the limbic system during epileptic and/or olfactory stimulation.

PubMed

Fornai, F; Bassi, L; Gesi, M; Giorgi, F S; Guerrini, R; Bonaccorsi, I; Alessandrì, M G

2000-01-01

Previous studies have shown that physiological stimulation of brain activity increases anaerobic glucose consumption, both in humans and in experimental animals. To investigate this phenomenon further, we measured extracellular lactate levels within different rat brain regions, using microdialysis. Experiments were performed comparing the effects of natural, physiological olfactory stimulation of the limbic system with experimental limbic seizures. Olfactory stimulation was carried out by using different odors (i.e. both conventional odors: 2-isobutyl-3-methoxypyrazine, green pepper essence; thymol; and 2-sec-butylthiazoline, a sexual pheromone). Limbic seizures were either induced by systemic injection of pilocarpine (200-400 mg/kg) or focally elicited by microinfusions of chemoconvulsants (bicuculline 118 pmol and cychlothiazide 1.2 nmol) within the anterior piriform cortex. Seizures induced by systemic pilocarpine tripled lactic acid within the hippocampus, whereas limbic seizures elicited by focal microinfusion of chemoconvulsants within the piriform cortex produced a less pronounced increase in extracellular lactic acid. Increases in extracellular lactate occurring during olfactory stimulation with the sexual pheromone (three times the baseline levels) were non-significantly different from those occurring after systemic pilocarpine. Increases in lactic acid following natural olfactory stimulation were abolished both by olfactory bulbectomy and by the focal microinfusion of tetrodotoxin, while they were significantly attenuated by the local application of the N-methyl-D-aspartate antagonist AP-5. Increases in hippocampal lactate induced by short-lasting stimuli (olfactory stimulation or microinfusion of subthreshold doses of chemoconvulsants, bicuculline 30 pmol) were reproducible after a short delay (1 h) and cumulated when applied sequentially. In contrast, limbic status epilepticus led to a long-lasting refractoriness to additional lactate-raising stimuli and there was no further increase in lactate levels when the olfactory stimulation was produced during status epilepticus. Increases in lactic acid following olfactory stimulation occurred with site specificity in the rhinencephalon (hippocampus, piriform and entorhinal cortex) but not in the dorsal striatum. Site specificity crucially relied on the quality of the stimulus. For instance, other natural stimuli (i.e. tail pinch) produced a similar increase in extracellular lactate in all brain areas under investigation. The major conclusion of this work is that the presentation of an odor known to be a rat pheromone results in lactate production as great as that induced by the systemic convulsant pylocarpine (maximum: 2.286+/-0.195 mM and 1.803+/-0.108 mM, respectively). This supports the notion that the great magnitude of lactate production known to accompany seizures can result from the intensified neural activity per se ("aerobic gycolysis"), not merely from local anoxia or other pathological changes.

THE STATE OF HEALTH OF PEOPLE SUBJECTED TO THE ACTION OF IONIZING RADIATION UNDER INDUSTRIAL-LABORATORY CONDITIONS (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozov, A.L.; Drogichina, E.A.; Kazakevich, M.A.

1957-01-01

A group of 60 people exposed to gamma radiation in the course of radiographic work, and a group of 170 people working with various radiation sources were subjected to clinical tests. An additional group of 40 people who showed symptoms of radiation sickness were subjected to more careful examination. The great majority of the subjects worked with radioactivity from 1 to 5 years, but about 20% were in contact with ionizing radiation for less than one year. Functional disturbances of the nervous system characterized by headaches, insomnia, increased tendency to fatigue, and weakness occurred three times more frequently with peoplemore » who worked from 2 to 5 years with radiation as compared with people who worked with radiation less than one year. A decrease in sensitivity to vibration was noted in people with signs of radiation sickness. An increased threshold of olfactory sensitivity to thymol (in 77% of the patients) and rosemary was observed in a group of 107 people. This insensitivity to smell was particularly pronounced in the second group of people who were in direct contact with radioactive materials. The arterial blood pressure was low (100 mm or lower) in 40% of the subjects, an indication of an increase in vascular permeability. There was a tendency for the total albumins to increase, but the increase of globulin was especially marked in that the normal ratio of albumin to globulin of l.3 to l.82 was lowered to 0.94 to 1.2. The leukocyte and thrombocyte count was quite variable. A tendency to a slight lymnphocytosis occurred more often. A neutrophilic shift to the left was frequently observed. In a significant number of cases there was a tendency to a moderate decrease in thrombocyte production. The most characteristic change in the blood was a heightened reticulocytosis observable in 40% of the subjects. There was a clear tendency to a prolonged bleeding time in almost one-half the patients, while other symptoms of hemorrhage such as a lower thrombocyte count were absent. The frequency of occurrence of cataracts in a group of 130 people could be correlated with the time of exposure to radiation. The relative frequency of cataracts was 7% for those under 40 years of age and 14% for those above 40 years of age for less than 5 years service. It was 25% for those under 40 years of age and 50% for those above 40 years of age for 6 to 10 years of service. It was 66% for those ahove 40 years of age with greater than 10 years of service. The possibility of some unknown process initiated by ionizing radiation that results in dystrophy changes in the eye cannot be excluded at this time. (TTT)« less

[Effect of a new low-cholesterol meat and vegetal product on correction of simulated lipid metabolism disorders in rats].

PubMed

Gorlov, I F; Slozhenkina, M I; Karpenko, E V; Giro, T M; Andreeva, S V

2015-01-01

The paper presents the biomedical evaluation of meat and cereal spread from low-cholesterol raw material with vegetable ingredients, recommended as a functional food. The experimental model with myocardial infarction like changes in hearts of the animals, accompanied by vascular changes similar to atherosclerotic changes in humans, as well as the modeling of the metabolic imbalance of lipids have been carried out by intramuscular injection of epinephrine and unbalanced feeding the animals with food rich in cholesterol, with a high content of carbohydrates and fats. Wistar rats were divided into 4 groups of 12 animals each. The rats in groups 1-3 were induced the cardio distress with intramuscular injection of epinephrine; group IV consisted of intact (healthy) animals. Dramatic changes in biochemical blood status that indicated heart disease have been observed within 2 days after the injection of epinephrine (0.2 ml per 1 kg of animal body weight) to the tested animals. During the experiment a sharp increase in activity of indicator enzymes of alanine aminotransferase (ALT) and aspartate aminotransferases (AST), with a predominance of AST over ALT, along with an increase in LDH activity have been observed. The 1.4-1.6 fold increase in blood serum creatinine has also been found. Later the animals in groups 1, 2, 3 with simulated cardio pathology were fed a ration with intervention of food rich in cholesterol, with a high content of carbohydrates and fats (50% of the diet) for a month for induction of lipid metabolism disorders. An increase in the concentration of cholesterol and triglycerides by 3 fold or more has been observed. In addition, an accumulation of sulfhydryl groups has been noted, as evidenced by increased rates of thymol. For further normalization of lipid metabolism, the animals in tested group I were fed the diet with intervention of spread, developed in accordance with GOST 12318-91 "Canned meat "Meat spread"; the rats of group 2 were fed with spread with vegetable supplements (pumpkin by-products and alginates), and group 3 received a standard diet within the next month. The results of biochemical blood serum studies have shown that the level of cholesterol, triglycerides, creatinine and sulphydryl groups in the experimental groups 1 and 2 decreased, indicating a positive influence on lipid metabolism and prevention of peroxides formation in the organism. These changes were more pronounced when meat product with plant additives and alginate was used in the diet. Only under the application of the meat-vegetable pate cholesterol level ceased to differ from that of the control group of animals. Based on the significant reduction of blood malondialdehyde level, antioxidant properties of vegetable supplements have been proven. The experimental data showed that the spread, developed on the basis of low-cholesterol raw meat with vegetable ingredients (pumpkin by-products and alginates) can be used to correct metabolic disorders of lipids, reducing the risk of cardio pathology in the body.

Antimosquito property of Petroselinum crispum (Umbellifereae) against the pyrethroid resistant and susceptible strains of Aedes aegypti (Diptera: Culicidae).

PubMed

Intirach, J; Junkum, A; Lumjuan, N; Chaithong, U; Jitpakdi, A; Riyong, D; Wannasan, A; Champakaew, D; Muangmoon, R; Chansang, A; Pitasawat, B

2016-12-01

The increasing and widespread resistance to conventional synthetic insecticides in vector populations has underscored the urgent need to establish alternatives in the mosquito management system. This study was carried out with the aim to investigate the antimosquito property, larvicidal and adulticidal potential, of plant products against both the pyrethroid-susceptible and resistant strains of Aedes aegypti. Seventeen plant products, including essential oils and ethanolic extracts, were obtained by steam distillation and extraction with 95 % ethanol, respectively. Their larvicidal activity was screened, using World Health Organization (WHO) procedures against A. aegypti, Muang Chiang Mai-susceptible (MCM-S) strain. The most effective product was a candidate for investigating larvicidal and adulticidal potential against three laboratory strains of A. aegypti, comprising MCM-S, Pang Mai Dang-resistant (PMD-R), and Upakut-resistant (UPK-R). Potential toxicity of the plant candidate was compared with that of synthetic temephos, permethrin, and deltamethrin. Chemical constituents of the most effective plant product also were analyzed by gas chromatography-mass spectrometry (GC-MS). Results obtained from the preliminary screening revealed the varying larvicidal efficacy of plant-derived products against MCM-S A. aegypti, with mortality ranging from 0 to 100 %. The larvicidal activity of seven effective plant products was found to be dose dependent, with the highest efficacy established from Petroselinum crispum fruit oil, followed by oils of Foeniculum vulgare, Myristica fragrans, Limnophila aromatica, Piper sarmentosum, Curcuma longa, and M. fragrans ethanolic extract (LC 50 values of 43.22, 44.84, 47.42, 47.94, 49.19, 65.51, and 75.45 ppm, respectively). Essential oil of P. crispum was then investigated further and proved to be a promising larvicide and adulticide against all strains of A. aegypti. The pyrethroid-resistant strains of both PMD-R and UPK-R A. aegypti showed significant resistance to temephos, permethrin, and deltamethrin in either the larval or adult stage. Interestingly, high susceptibility to P. crispum oil was observed in the larvae and adults of MCM-S, which are pyrethroid-susceptible A. aegypti, and comparable to those of the pyrethroid-resistant strains, PMD-R and UPK-R. GC-MS analysis of P. crispum oil demonstrated that 19 compounds, accounting for 98.25 % of the whole oil, were identified, with the main constituents being thymol (42.41 %), p-cymene (27.71 %), and γ-terpinene (20.98 %). In conclusion, the profound larvicidal and adulticidal potential of P. crispum oil promises to form a new larvicide and adulticide against either the pyrethroid-susceptible or resistant strain of A. aegypti. Consequently, P. crispum oil and its constituents can be used or incorporated with other chemicals/measures in integrated mosquito management for controlling A. aegypti, particularly in localities with high levels of pyrethroid and organophosphate resistance.

Effect of oral calcium administration on the cure and reproductive performance of Holstein cows diagnosed with puerperal metritis.

PubMed

Pinedo, Pablo; Velez, Juan; Solano, Gilberto; Rodriguez, Nelson; Naves, Julianne; Schuenemann, Gustavo M; Risco, Carlos

2017-04-01

Our objective was to evaluate the effect of oral calcium administration on clinical cure, survival, subsequent presentation of peripartal health disorders, and reproductive performance of Holstein cows diagnosed with puerperal metritis (PM) under certified organic management. A second objective was to evaluate the metabolic status at calving and at the time of PM diagnosis (d 0) in affected and matched healthy cows. Cows diagnosed with PM (n = 200) were assigned randomly to receive 1 of 2 treatments: (1) control received 3.75 mL of Optimum UterFlush [Van Beek Natural Science, Orange City, IA, containing yucca extract, cinnamaldehyde, thymol, and a proprietary blend of carvacrol (4-isopropyl-2-methylphenol, at 0.47 g/mL)] diluted in 117 mL of distilled water by intrauterine infusion, administered every other day for a total of 3 treatments (n = 100); (2) calcium-supplemented (CA) received the same intrauterine treatment plus 6 oral capsules providing calcium ('O' Cal-D Cap, Bio-Vet Inc., Barneveld, WI; 7.5-9.0 g of Ca/capsule) once per day, for 3 consecutive days after diagnosis of PM. All cows received hypertonic saline solution (500 mL of 7.2% solution i.v. once), dextrose (500 mL of 50% solution i.v. once), and oral aspirin (5 boluses/d for 3 d). Outcome variables included fever, presence of fetid vaginal discharge, and uterine score at d 6 and 14 after diagnosis, survival at 30 and 100 d in milk, reproductive performance, and incidence of other health disorders after PM. A group of 200 control healthy cows (CH) was matched with PM cows at d 0, and calcium and fatty acid serum concentrations were determined at calving and at the day of diagnosis of PM (d 0). Calcium status was also assessed in PM cows at d 1, 2, 3, and 6 after diagnosis. Treatment effects were tested by logistic regression, repeated measures analysis, and ANOVA. Average calcium serum concentrations at d 0 were lower in PM cows (1.57 mmol/L) compared with CH cows (2.10 mmol/L). In PM cows, calcium concentrations at d 1, 2, 3, and 6 after diagnosis were significantly higher in the CA group. Fatty acid serum concentrations at calving and at d 0 were higher in PM cows compared with CH cows (0.48 vs. 0.37 mmol/L and 0.49 vs. 0.35 mmol/L, for calving and d 0). No effect was observed for calcium administration on health and survival outcomes. However, the proportion of cows inseminated by 150 d in milk was greater for CA compared with control cows (66 vs. 55%). In conclusion, supplementing oral calcium at the time of diagnosing PM had no effect on health. High fatty acid concentrations at calving were significant risk factors for occurrence of PM. Furthermore, cows affected with PM had lower calcium and higher fatty acid concentrations than CH cows at d 0. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Authentic Learning Enviroment in Analytical Chemistry Using Cooperative Methods and Open-Ended Laboratories in Large Lecture Courses

NASA Astrophysics Data System (ADS)

Wright, John C.

1996-09-01

It is recognized that a need exists to move from the passive learning styles that have characterized chemistry courses to an active style in which students participate and assume responsibility for their learning (1 - 5). In addition, it is argued that course reform should be linked to authentic student achievement, so that students can actively experience the feelings of practicing professionals (6). Course experiments where such changes have been introduced have proven successful but the number of examples of such changes is limited in the higher level courses or courses with large enrollments (7 - 11). In this paper, a one-semester introductory analytical chemistry course is described that accomplishes this goal by the use of open-ended laboratories, cooperative learning, and spreadsheet programs. The course uses many of the ideas described by Walters (7). It is offered at the upperclass level to nonmajors and at the freshman level to students with solid chemistry backgrounds from high school. Typically there are 90 students, who are divided into 5 sections. A teaching assistant is assigned to each section. The course has two 4-hour laboratories and two or three lectures each week (depending on whether it is the upperclass or freshman course). The heart of the course changes is the use of open-ended laboratory experiments in the last half of the course. A sample group project is to have the students develop a mixture of acid-base indicators that can serve as a spectroscopic pH meter. These projects are enhanced by dividing the students into teams of four who take charge of all aspects of accomplishing the projects' goals. Since there are many skills required to make these projects work, the first half of the course is spent developing the individual conceptual, computational, laboratory, problem solving, and group skills so students are prepared for the last half. These changes have markedly improved the student attitudes towards each other and towards learning chemistry, in addition to increasing the depth of coverage of the material and the students' comprehension levels. Although these benefits are usually expected from small colleges, it has become clear that they can also be achieved in large-enrollment universities. Course Elements The important elements in the open-ended projects are identified during the planning of the course and are brought into the course from its beginning in order to establish a central theme that continues throughout the course. Eight changes have been made in the course where these themes are emphasized: an absolute grading scale is announced at the beginning of the course a student board of directors is appointed to oversee all aspects of the course students read and analyze research papers interactive techniques are introduced in the lecture spreadsheet programs are used for homework and laboratory problems cooperative examinations complement traditional examinations open-ended laboratory projects replace many standard laboratory experiments Grading The absolute grading scale is recognized as an essential element to a course where students work cooperatively, because the competition in a course graded on the curve discourages cooperation (4). Grades are determined by a mixture of traditional examinations and quizzes, cooperative examinations, problem sets, laboratory grades based on quantitative unknowns, and group and individual grades on open-ended projects. Several methods have been used to arrive at individual grades for group projects, but the most effective has been a peer grade assigned by the team members. For a four-member team, each individual will receive grades from the other three members and the results are averaged. The individuals consider a person's effort, team skills, and contributions. The individual grades are then normalized to the team grade. Student Formative Assessment A student board of directors is appointed from volunteers using student diversity and representation from all course sections as selection criteria. The board members provide rapid feedback and formative assessment about course operation, make decisions about course issues, and bring up issues that are important for the class. They have power over all aspects of the course including grading, but the instructor retains a veto privilege (thus far unused). Research Papers Students are assigned to groups at the beginning of the first laboratory and given a professional paper to read. In order to help them understand the paper and to give each individual an important part in the group, the four teaching assistants in the course hold discussion sections on the important aspects of the paper. Representatives from each group attend each of the discussions and then return to their teams. Together, the group members pool their understanding and address the specific questions that test and deepen their understanding of the paper. The answers are written up and the team meets with the course instructors to discuss their insights. This group exercise builds group skills and introduces key concepts that will become important in the group projects. Later, research paper analysis is used to give more realistic problems for assimilating the course material. As an example, a paper by Yamazaki et al. on "Spectroscopic Determination of pH and Its Application to the Determination of Thermodynamic Equilibrium Constants" (12) was chosen to begin the course. This paper would complement a project introduced later, where students develop a mixture of indicators to determine pH. The paper measured the absorption spectrum of two acid-base indicators in a carefully prepared buffer having an accurately known acid dissociation constant. After making appropriate activity corrections, the authors showed that the indicator could be used to measure pH in other solutions with an accuracy that exceeded pH meter measurements. For this example, the four students in a group would divide up to meet as representatives with each of the four teaching-assistant discussion sections, to learn about spectroscopic measurements, statistics and error analysis, thermodynamic and equilibrium concepts, and team management. This introduction empowered individuals in a specific area so they would have a defined place on the team during the initial meeting. The team addressed 10 questions such as calculating the ratio of the acid and conjugate base species of the indicator from data in a figure; determining why the data were weighted differently at different wavelengths and why there was no weight at an isobestic point; predicting the change in the absorbances if the temperature, ionic strength, or pH changed; and evaluating whether the temperature-induced changes in absorption could form the basis of a spectroscopic thermometer. Lecture Activities Group activities were introduced into the lecture in the form of think-pair-share exercises, collaborative problem solving, concept tests, and list generation (13-15). For think-pair-share, a simple numerical or conceptual problem is stated and after briefly thinking about its answer, students discuss their ideas for answers. Representative groups share their answers with the class or a class vote is taken on the correct answer from a list of nominations. An example of collaborative problem solving is calculating points in a chelation titration for different pH values and auxiliary complexing agent concentrations. The answers are pooled on overhead graphs corresponding to the different conditions. The class then discusses the effects of changing the competing equilibria conditions on the titration curves. The answers are duplicated and distributed so each student has a complete set of solved examples under varying experimental conditions. An example of a list generation exercise is to have students identify all factors that lead to chromatographic peak broadening. Cooperative Examinations The traditional examination format has been augmented in this course by cooperative take-home examinations. Students can discuss problems but their answers must be their own. This format allows more realistic and complex questions, although there are limits to the sophistication level that is achievable. Typical questions might include simulating the spectra that result for different pH and reagent concentrations when Cd2+, a chelating agent, and a complexation indicator are mixed. The question uses concepts that appeared in the first research paper exercise, but it requires reformulating it in a different context. Students report that the examinations are a reliable indicator of their comprehension and problem-solving skills. Correlation plots of cooperative vs. traditional examination results show no significant differences. Spreadsheets Spreadsheet programs have become recognized as very powerful devices for teaching in analytical chemistry because they provide the power required to tackle complex equilibria. At the same time, they are accessible to the unsophisticated student and they are important tools for a student to master. The spreadsheet programs are used in both lecture and laboratory contexts. Exercises are assigned that increase student proficiency gradually. Starting from a simple successive approximation exercise, students advance to creating species distribution functions (alpha-plots) for weak acids and then to modeling a titration curve including nonideality corrections. They also use computers for data acquisition in conjunction with a scanning spectrophotometer and data analysis of the overlapping spectra in a two-component mixture. Open-Ended Laboratory Projects The open-ended projects are the heart of the course. They have well-defined goals, but students are free to use their own creativity in reaching the goals. A listing of projects that have been used in the course is given in Table 1. The measurement of the pKa of an indicator and the development of a spectroscopic pH meter were projects used in the semester when the first research paper was the Yamazaki et al. "Spectroscopic Determination of pH and Its Application to Determination of Thermodynamic Equilibrium Constants". The project on measuring the pKa of an indicator was a reproduction of the work in the paper with a different indicator. A buffer with a well-known acid dissociation constant was prepared by accurate mixing of appropriate acids and conjugate bases so that pH could be calculated to four significant figures. Accurate absorbance measurements of the acid/conjugate base forms of the indicator then gave accurate values of pKa of the indicator. Different groups in the class measured different indicators and the results were pooled so that students had access to all the information on all the indicators. The development of a spectroscopic pH meter used the database to select a mixture of indicators that would give spectroscopic selectivity for pH over a wide pH range. Example student results are shown in Figures 1 and 2. Figure 1 shows the absorbance spectra of a mixture of thymol blue, methyl orange, phenol red, and chlorophenol red for 8 pH values from 1.5 to 9.4. Figure 1. Spectra of a methyl orange, phenol red, chlorophenol red, thymol blue mixture for a series of pH values. Figure 2 shows a typical fit that was obtained for a pH = 6.3404, along with the contributions from each of the four indicators. Figure 2. Comparison of the theoretical and experimental absorption spectrum for the pH = 6.34 sample in Figure 1 and the contributions to the theoretical spectrum from each of the individual indicators. Table 2 is a compilation of the results for each of the pH values showing the results of a pH meter measurement, a calculated pH based on knowing the buffer mixture, and the pH that resulted from the spectroscopic fitting procedure. There are obvious differences in the three measurements that need further work, but the results also show clearly that the procedure is feasible and good-quality results can be obtained. Alternative measurements of buffer solutions using pH meter readind, calculated pH based on known pKa values of buffer and known concentrations of buffer species, and pH determined by fitting absorption spectra of inticator mixture. Many of the projects come from traditional laboratory experiments. For example, the carbonate determination in a NaOH titrant project was adapted from an existing experiment where students determine the concentration of H3PO4 with a pH titration. The two equivalence points require equal volumes of NaOH titrant if there was no CO32- absorbed from CO2 in the air. If there is CO32-, the equivalence points require different amounts of titrant because the CO32- reacts with more H+ at the more acidic equivalence point. Consequently, the NaOH solutions are made by diluting saturated solutions and the added water is sparged or boiled to eliminate CO2 for the traditional experiment. For the project, students are asked to design an assay procedure that can determine the amount of CO32- in the NaOH using the H3PO4 titration. They must first establish a relationship between the volumes measured in the titration and the concentrations. Typically, they will choose either to standardize the procedure using standard NaOH and Na2CO3 solutions or to simulate the titration using the known values of the acid dissociation constants. They must then design and implement a procedure that uses appropriate concentrations and volumes. Often, students find that their results are not reproducible or that the simulations don't fit their data. An example of experimental data and a simulation are shown in Figure 3 for solutions containing no CO32- (Fig. 3a) and 20% CO32- (Fig. 3b). Figure 3. Titration of two solutions with NaOH where (a) the solution is H3PH4 and (b) the solution is 80% H3PO4 and 20% Na2CO3. This problem is caused by the loss of CO2 at the acidic pH values when the CO32- is in the H2CO3 form. Creative students transcend the problem by reversing the usual roles of the NaOH and H3PO4. When H3PO4 is used as the titrant, the pH is not acidic enough to cause CO2 loss until the end of the titration. An example of this approach is shown in Figure 4. Figure 4. Titration of an NaOH solution with an H3PH4 / Na2CO3 mixture. The open-ended projects are conceptually simple; but there are enough details and enough unanticipated problems arise during the projects to provide students with many opportunities for creativity and practice in problem solving. In addition, the students struggle with course concepts in the context of a realistic problem, and this opportunity provides much greater insight into the course material. It also gives better insights into the way that science is actually practiced. Students should be made aware that experiments almost never work the first time because it is difficult to anticipate all the details and complications in a real system. It is an important lesson that all scientists learn from experience. They should recognize that an experiment does not fail if it doesn't work as anticipated, as long as it provides further insight for the next try. The group project final report is done by the team. It includes description of the experimental plan, results, and discussion. The team members meet with the teaching assistant and faculty member to discuss the details of the project. The discussions have a professional character, the science in the projects being discussed without simplifications. It is an opportunity to reflect on the unsolved problems and the future directions that could be pursued. It is also an opportunity to reflect on the relationship between their experiences and the experiences that professionals have. The typical student group has invested a large amount of time and effort in the project and is proud of its accomplishments. Above all else, it is important that the discussion with the course instructors recognize the accomplishments and affirm the pride that is shown by the students. Evaluation The student response to these course changes was evaluated by questionnaires, free-written responses, and informal discussions with individual students. Table 3 gives the questionnaire statements and the mean student response in the freshman and upperclass courses, based on a scale from 1 to 5 (strongly disagree to strongly agree). The means for the scores are shown with a grading scale of 1 to 5 representing strongly diagree to strongly agree. The student response was favorable for each of the major course elements and for the overall course. The free-written responses took two forms. In the first, students were asked to write a critical evaluation of the team approach; in the second, they were asked to identify the greatest strengths and weaknesses of the group approach. Table 4 summarizes the student responses to the latter question by grouping them into 9 major categories along with the fraction of the comments that fell into each category. The percentages given represent the fraction of all comments made by all students that fall into each category. On average, each student made 2.1 comments. The greatest strengths were divided between the increased understanding of the course material, the enjoyment of working with problems that were more representative of real life, the thinking that was demanded by the course structure, the experience with working together in groups, and the opportunity to exercise creativity in the problem solving. Less frequently mentioned were comments about the increased depth of coverage, the challenge and sense of accomplishment, the opportunity to learn spreadsheet programs, and the development of problem solving skills. The greatest weaknesses were divided between the amount of time required in the course, problems in working together as a group, inadequate preparation for understanding the projects, technical difficulties associated with equipment and computer operation, and inadequate time to finish the project in a satisfying way. Less frequently mentioned were comments that the depth was too great to handle, the expectation level for the course was too high to sustain motivation, the projects became tedious during the data collection, and students got lost in the material. All of these evaluation exercises were consistent with each other. Ninety percent of the students in both the freshman and upper-level courses felt that the group work increased their understanding of the course material and 93% felt that the course required a great deal of time (average estimate was 18 hours of outside work). There were differences between the freshman and the upper-level courses in whether the increased learning was worth the additional time. Table 3 shows that freshman students were much more receptive to spending time if it resulted in increased learning. Student discussions make it clear that upperclassmen feel much more comfortable with a traditional course structure and are skeptical about changing it. One upperclassman made it particularly clear when he stated that he appreciated the effort being expended on changing the course and that he could see why it was valuable. Nevertheless, he and his associates were close to graduation and they were most interested in getting out with the minimum amount of hassle. The same general themes pervade the free-written responses but these contain more insight into the student feelings. In fact, there is a richness in the responses that cannot be easily categorized or condensed but will be the subject of a future paper. Table 5 gives example comments that best represent the student's perceptions and feelings about the course. They reflect the complex interplay between the three major themes of a course involving cooperative learning. The students are enthusiastic about the opportunity to work on problems that have elements of authenticity, the realization that their skill and mastery are improved by experiencing the course material in a specific context, and the cooperative interactions with fellow students. They also realize and accept that these accomplishments have been at the cost of increased work load. A number of other important questions have not been addressed by the evaluation data given above. In particular, it is important to determine whether the course structure has improved the students' learning. This question is currently the focus of an extensive parallel study with a control class and the results will be published separately. Conclusions One of the most effective ways to accomplish effective learning is to involve students in original research. There are many constraints that prevent this approach from being applied to nonchemistry students, particularly at institutions with large enrollments. The open-ended laboratory approximates the research experience that can be implemented in large-enrollment courses. The open-ended projects need not be sophisticated to engage the imagination and excitement of students. As is clear from the evaluations, students welcome an opportunity to think about and work hard on problems that haven't been worked out so there is room for discovery and creativity, even on a small scale. There were many examples of the cooperative learning aspects of the course that mirror what other cooperative learning approaches have experienced (1-11): community building increased motivation reduction in alienation and anonymity improvement in team skills active student participation in the learning process increased comprehension and accomplishment These benefits are usually achieved in institutions with small class sizes and more interaction between students and faculty, but this course experiment makes it clear that they can be realized at large institutions as well. There are longer-range benefits to undergraduate education. It is recognized that successful curriculum reform requires more than improved lectures, course materials, churning of the curriculum, etc. It requires a change in the way that faculty and students view themselves (4). It is clear that this course model is an example of one that replaces the traditional model of passive learners and inspired lecturers by a model where the students take an active and responsible part in the learning process and faculty members facilitate learning by preparing a learning environment that will challenge and empower students. These changes are fundamental and represent new traditions that guide students and faculty into a new approach to education. It is important to extend such approaches to other upper-level courses in the chemistry curriculum. Acknowledgment This work was supported by the National Science Foundation under grant 94-50615. Literature Cited 1. Moll, M. M.; Allen, R. D. J. College Sci. Teach. 1982, 11, 219-222. 2. Tobias, S. Revitalizing Undergraduate Science: Why Some Things Work and Most Don't; Research Corporation: Tucson, AZ, 1992. 3. Tobias, S. They're Not Dumb, They're Different: Stalking the Second Tier; Research Corporation: Tucson, AZ, 1990. 4. MacGregor, J. New Directions for Teaching and Learning 1990, 42, 19 -30. 5. Bunce, D.M. J. Chem. Educ. 1993, 70, 179 and associated papers. 6. Newmann, F. M. Phi Delta Kappan, 1991, 72, 458-463. 7. Walters, J. P. Anal. Chem. 1991, 63, 977A-985A, 1077A-1087A, 1179A-1191A. 8. Ricci, R. W.; Ditzler, M. A. J. Chem. Educ. 1991, 68, 228-232. 9. Laws, P. W. Physics Today, Dec. 1991, pp 24-31. 10. Pickering, M. J. Chem. Educ. 1985, 62, 874-875. 11. Alty, L. T. J. Chem. Educ. 1993, 70, 663-665. 12. Yamazaki, H.; Sperline, R. P.; Freiser, H. Anal. Chem. 1992, 64, 12720-2725. 13. Kagan, S. Cooperative Learning; Resources for Teachers, Inc.: San 1Juan Capistrano, CA, 1992. 14. Johnson, D. W. ; Johnson, R. T.; Smith, K. A. Active Learning: 1Cooperation in the College Classroom; Interaction Book Co.: Edina, 1MN, 1991. 15. Mazur, E. Peer Instruction: A User's Manual (Department of Physics, Harvard University, Cambridge, MA, 1993).