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Sample records for inhibits in-vitro candida

  1. A Novel Antifungal Is Active against Candida albicans Biofilms and Inhibits Mutagenic Acetaldehyde Production In Vitro

    PubMed Central

    Nieminen, Mikko T.; Novak-Frazer, Lily; Rautemaa, Vilma; Rajendran, Ranjith; Sorsa, Timo; Ramage, Gordon; Bowyer, Paul; Rautemaa, Riina

    2014-01-01

    The ability of C. albicans to form biofilms is a major virulence factor and a challenge for management. This is evident in biofilm-associated chronic oral-oesophageal candidosis, which has been shown to be potentially carcinogenic in vivo. We have previously shown that most Candida spp. can produce significant levels of mutagenic acetaldehyde (ACH). ACH is also an important mediator of candidal biofilm formation. We have also reported that D,L-2-hydroxyisocaproic acid (HICA) significantly inhibits planktonic growth of C. albicans. The aim of the present study was to investigate the effect of HICA on C. albicans biofilm formation and ACH production in vitro. Inhibition of biofilm formation by HICA, analogous control compounds or caspofungin was measured using XTT to measure biofilm metabolic activity and PicoGreen as a marker of biomass. Biofilms were visualised by scanning electron microscopy (SEM). ACH levels were measured by gas chromatography. Transcriptional changes in the genes involved in ACH metabolism were measured using RT-qPCR. The mean metabolic activity and biomass of all pre-grown (4, 24, 48 h) biofilms were significantly reduced after exposure to HICA (p<0.05) with the largest reductions seen at acidic pH. Caspofungin was mainly active against biofilms pre-grown for 4 h at neutral pH. Mutagenic levels (>40 µM) of ACH were detected in 24 and 48 h biofilms at both pHs. Interestingly, no ACH production was detected from D-glucose in the presence of HICA at acidic pH (p<0.05). Expression of genes responsible for ACH catabolism was up-regulated by HICA but down-regulated by caspofungin. SEM showed aberrant hyphae and collapsed hyphal structures during incubation with HICA at acidic pH. We conclude that HICA has potential as an antifungal agent with ability to inhibit C. albicans cell growth and biofilm formation. HICA also significantly reduces the mutagenic potential of C. albicans biofilms, which may be important when treating bacterial-fungal biofilm

  2. New synthetic sulfone derivatives inhibit growth, adhesion and the leucine arylamidase APE2 gene expression of Candida albicans in vitro.

    PubMed

    Staniszewska, Monika; Bondaryk, Małgorzata; Ochal, Zbigniew

    2015-01-15

    The successful preventing and effective treatment of invasive Candida albicans infections required research focused on synthesis of new classes of agents and antifungal activity studies. Bromodichloromethyl-4-chloro-3-nitrophenyl sulfone (named compound 6); dichloromethyl-4-chloro-3-nitrophenyl sulfone (named 7); and chlorodibromomethyl-4-hydrazino-3-nitrophenyl sulfone (named 11) on inhibition of planktonic cells' growth, leucine arylamidase APE2 gene expression, and adhesion to epithelial cells were investigated. In vitro anti-Candida activities were determined against wild-types, and the morphogenesis mutants: Δefg1 and Δcph1. MICs of compounds 6, 7 and 11 (concentrated at 0.25-16μg/ml) were determined using the Clinical and Laboratory Standards Institute Broth Microdilution Method (M27-A3 Document). APE2 expression was analyzed using RT-PCR; relative quantification was normalized against ACT1 in cells growth in YEPD and on Caco-2 cell line. Adherence assay of C. albicans to Caco-2 was performed in 24-well-plate. The structure activity relationship suggested that sulfone containing hydrazine function at C-1 (compound 11) showed higher antifungal activity (cell inhibition%=100 at 1-16μg/ml) than the remaining sulfones with chlorine at C-1. Δcph1/Δefg1 was highly sensitive to compound 11, while the sensitivity was reduced in Δcph1/Δefg1::EFG1 (%=100 at 16-fold higher concentration). Compound 11 significantly affected adherence to epithelium (P ⩽0.05) and hyphae formation. The APE2 up-regulation plays role in sulfones' resistance on MAP kinase pathway. Either CPH1 or EFG1 play a role in the resistance mechanism in sulfones. The strain-dependent phenomenon is a factor in the sulfone resistance mechanism. Sulfones' mode of action was attributed to reduced virulence arsenal in terms of adhesiveness and pathogenic potential related to the APE2 expression and morphogenesis. PMID:25515956

  3. In Vitro Models for Candida Biofilm Development.

    PubMed

    Krom, Bastiaan P; Willems, Hubertine M E

    2016-01-01

    Development of Candida spp. biofilms on medical devices such as catheters and voice prosthesis has been recognized as an increasing clinical problem. Different in vitro models are presented with increasing complexity. Each model system can be utilized for analysis of new active compounds to prevent or treat Candida biofilms as well as to study molecular processes involved in biofilm formation. Susceptibility studies of clinical isolates are generally performed in a simple 96-well model system similar to the CLSI standard. In the present chapter, optimized conditions that promote biofilm formation within individual wells of microtiter plates are described. In addition, the method has proven useful in preparing C. albicans biofilms for investigation by a variety of microscopic and molecular techniques. A more realistic and more complex biofilm system is presented by the Amsterdam Active Attachment (AAA) model. In this 24-well model all crucial steps of biofilm formation: adhesion, proliferation, and maturation, can be simulated on various surfaces, while still allowing a medium throughput approach. This model has been applied to study susceptibility, complex molecular mechanisms as well as interspecies (Candida-bacterium) interactions. Finally, a realistic microfluidics channel system is presented to follow dynamic processes in biofilm formation. In this Bioflux-based system, molecular mechanisms as well as dynamic processes can be studied at a high time-resolution. PMID:26519068

  4. In Vitro Anti-Candida Activity of Zataria multiflora Boiss

    PubMed Central

    Dabbagh, Muhammad Ali; Fouladi, Zahra

    2007-01-01

    Zataria multiflora Boiss known as Avishan Shirazi (in Iran) is one of the valuable Iranian medicinal plants. The aim of study was to evaluate anti-Candida activity of Z. multiflora against different species of Candida in vitro. Anti-Candida activity of the aqueous, ethanolic and methanolic maceration extract of the aerial parts of Z. multiflora Boiss was studied in vitro. Anti-Candida activity against Candida species was done using serial dilutions of extracts in Sabouraud's dextrose agar. Minimal inhibitory concentration (MIC) of the methanolic and ethanolic extracts was 70.7 and 127 mg l−1, respectively. Aqueous extract showed no remarkable activity against Candida species. We conclude that methanolic extract of the aerial parts of Z. multiflora Boiss has more anti-Candida effect at 70.7 mg l−1 compared to ethanolic extract 127 mg l−1. In addition, the isolates of Candida parapsilosis were more susceptible to methanolic extract than other tested species. PMID:17965766

  5. In vitro pharmacodynamic modelling of anidulafungin against Candida spp.

    PubMed

    Gil-Alonso, Sandra; Jauregizar, Nerea; Ortega, Ignacio; Eraso, Elena; Suárez, Elena; Quindós, Guillermo

    2016-03-01

    The aim of this study was to fit anidulafungin in vitro static time-kill data from nine strains of Candida with a pharmacodynamic (PD) model in order to describe the antifungal activity of this drug against Candida spp. Time-kill data from strains of Candida albicans, Candida glabrata and Candida parapsilosis clades were best fit using an adapted sigmoidal Emax model and resulted in a set of PD parameters (Emax, EC50 and Hill factor) for each fungal strain. The data were analysed with NONMEM 7. Anidulafungin was effective in a species- and concentration-dependent manner against the strains of C. glabrata and C. parapsilosis clades as observed with the EC50 estimates. Maximum killing rate constant (Emax) values were higher against C. glabrata and C. parapsilosis complex strains. In conclusion, we demonstrated that the activity of anidulafungin against Candida can be accurately described using an adapted sigmoidal Emax model. PMID:26857078

  6. Sodium houttuyfonate and EDTA-Na₂ in combination effectively inhibits Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans in vitro and in vivo.

    PubMed

    Huang, Weifeng; Duan, Qiangjun; Li, Fang; Shao, Jing; Cheng, Huijuan; Wu, Daqiang

    2015-01-01

    Sodium houttuyfonate (SH) has been found to be mildly anti-pathogenetic against the planktonic and biofilm phenotypes of Pseudomonas aeruginosa. Here, we have attempted to investigate further the anti-pathogenicity of SH and EDTA-Na₂ in combination and in vitro and in vivo against planktonic and biofilm phenotypes of Pseudomonas aeruginosa (16 strains), Staphylococcus aureus (13 strains) and Candida albicans (13 strains). The antimicrobial activity of SH against all three pathogens increased dramatically when it was combined with EDTA-Na₂, in vitro. Toxic reactions to the drugs when administered orally were insignificant in mice; no abnormalities were observed in the internal organs, such as the lungs and kidneys. Finally, the results of in vivo studies indicate that SH could extend the lifespan of infected animals when administered in combination with EDTA-Na2. Therefore, the results of the present study lead us to suggest that SH could be a promising antimicrobial agent and that SH combined with EDTA-Na₂ has the potential to be an excellent choice of drug for combating bacterial infections clinically. PMID:25467165

  7. In vitro inhibition of adhesion of Candida albicans clinical isolates to human buccal epithelial cells by Fuc alpha 1----2Gal beta-bearing complex carbohydrates.

    PubMed Central

    Brassart, D; Woltz, A; Golliard, M; Neeser, J R

    1991-01-01

    The role of cell surface glycoconjugates as possible adhesion receptors for Candida albicans yeasts on human buccal epithelial cells was investigated by using a quantitative radiometric assay involving 14C-metabolically labeled microorganisms. Various structurally defined soluble glycopeptides and oligosaccharides were tested at a low concentration (1 mg/ml) for their ability to competitively inhibit yeast adhesion to such exfoliated cells. Comparisons were also made with various molecular species previously proposed to act as adhesion molecules. A preparation of glycopeptides derived from pooled human newborn meconiums inhibited the attachment (up to 55%) of all three clinical isolates examined. The mild hydrolysis of fucosyl residues from the above mixture totally abolished its inhibitory potency. By using human milk oligosaccharide probes, the minimal structural requirement for activity was found to be the Fuc alpha 1----2Gal beta determinant (the H sugar sequence found on all blood group substances of the ABO [H] system). By contrast, the fucosylated determinants of the Lewis blood group system were found to be totally inactive. Total adhesion inhibitions were never obtained in the present experiments, suggesting that H disaccharide-bearing cell surface glycoconjugates could act as host receptors for C. albicans on human buccal epithelial cells as a part of a mechanism involving multireceptor specificities. PMID:2019432

  8. In vitro activity of eugenol against Candida albicans biofilms.

    PubMed

    He, Miao; Du, Minquan; Fan, Mingwen; Bian, Zhuan

    2007-03-01

    Most manifestations of candidiasis are associated with biofilm formation occurring on the surfaces of host tissues and medical devices. Candida albicans is the most frequently isolated causative pathogen of candidiasis, and the biofilms display significantly increased levels of resistance to the conventional antifungal agents. Eugenol, the major phenolic component of clove essential oil, possesses potent antifungal activity. The aim of this study was to investigate the effects of eugenol on preformed biofilms, adherent cells, subsequent biofilm formation and cell morphogenesis of C. albicans. Eugenol displayed in vitro activity against C. albicans cells within biofilms, when MIC(50) for sessile cells was 500 mg/L. C. albicans adherent cell populations (after 0, 1, 2 and 4 h of adherence) were treated with various concentrations of eugenol (0, 20, 200 and 2,000 mg/L). The extent of subsequent biofilm formation were then assessed with the tetrazolium salt reduction assay. Effect of eugenol on morphogenesis of C. albicans cells was observed by scanning electron microscopy (SEM). The results indicated that the effect of eugenol on adherent cells and subsequent biofilm formation was dependent on the initial adherence time and the concentration of this compound, and that eugenol can inhibit filamentous growth of C. albicans cells. In addition, using human erythrocytes, eugenol showed low hemolytic activity. These results indicated that eugenol displayed potent activity against C. albicans biofilms in vitro with low cytotoxicity and therefore has potential therapeutic implication for biofilm-associated candidal infections. PMID:17356790

  9. In vitro shoot growth of Brugmansia x candida Pers.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to improve the growth of in vitro shoot cultures of Brugmansia × candida 'Creamsickle'. Several mineral nutrient experiments were conducted to determine the effect of NH4+, NO3-, K+, FeSO4/EDTA, ZnSO4, MnSO4, and CuSO4 on quality, leaf width and length, size and weigh...

  10. The In Vitro Antimicrobial Activities of Metabolites from Lactobacillus Strains on Candida Species Implicated in Candida Vaginitis

    PubMed Central

    Ogunshe, Adenike A O; Omotoso, Mopelola A; Bello, Victoria B

    2011-01-01

    Background: Research from developing countries, such as Nigeria, on Lactobacillus species in the female urogenital tract and their role as a barrier to vaginal infection is limited. Therefore, the aim of this study was to assess the clinical biotherapeutic potential of indigenous Lactobacillus species. Methods: Antimicrobial metabolites production were characterised using simple and easily reproducible qualitative and quantitative methods. The in vitro inhibitory effect of Lactobacillus antimicrobials on vulvovaginal candidiasis–associated Candida species was investigated using modified agar spot and agar well-diffusion methods. Results: The maximum levels of lactic acid, hydrogen peroxide, and diacetyl from 20 vaginal Lactobacillus strains from diseased subjects were 1.46 mg/L, 1.36 mmol/L, and 1.72 mg/L respectively. From the 4 healthy subjects, the maximum level of lactic acid was 1.08 mg/L; hydrogen peroxide, 1.36 mmol/L; and diacetyl, 0.86 mg/L. The maximum productions of these substances occurred between 72 and 120 hours of incubation. The in vitro antagonistic activities of vaginal L. acidophilus, L. fermentum, L. brevis, L. plantarum, L. casei, L. delbrueckii, and L. jensenii from diseased subjects inhibited a maximum of 5.71% of the 35 Candida species tested, while vaginal L. acidophilus and L. plantarum from healthy subjects inhibited between 57.1% and 68.6% of Candida species in vitro. Conclusion: Antimicrobial-producing lactobacilli can be considered as adjunct biotherapeutic candidates for the treatment of vulvovaginal candidiasis. PMID:22589669

  11. Chrysin Inhibits Lymphangiogenesis in Vitro.

    PubMed

    Prangsaengtong, Orawin; Athikomkulchai, Sirivan; Xu, Jiuxiang; Koizumi, Keiichi; Inujima, Akiko; Shibahara, Naotoshi; Shimada, Yutaka; Tadtong, Sarin; Awale, Suresh

    2016-01-01

    The induction of lymphangiogenesis is an important process to promote cancer growth and cancer metastasis via the lymphatic system. Identifying the compounds that can prevent lymphangiogenesis for cancer therapy is urgently required. Chrysin, 5,7-dihydroxyflavone, a natural flavone extracted from Thai propolis, was used to investigate the effect on the lymphangiogenesis process of TR-LE, rat lymphatic endothelial cells. In this study, maximal nontoxic doses of chrysin on TR-LE cells were selected by performing a proliferation assay. The process of lymphangiogenesis in vitro was determined by cord formation assay, adhesion assay and migration assay. Chrysin at a nontoxic dose (25 μM) significantly inhibited cord formation, cell adhesion and migration of TR-LE cells when compared with the control group. We also found that chrysin significantly induced vascular endothelial growth factor C (VEGF-C) mRNA expression and nitric oxide (NO) production in TR-LE cells which was involved in decreasing the cord formation of TR-LE cells. In conclusion, we report for the first time that chrysin inhibited the process of lymphangiogenesis in an in vitro model. This finding may prove to be a natural compound for anti-lymphangiogenesis that could be developed for use in cancer therapy. PMID:27040620

  12. Oral administration of the broad-spectrum antibiofilm compound toremifene inhibits Candida albicans and Staphylococcus aureus biofilm formation in vivo.

    PubMed

    De Cremer, Kaat; Delattin, Nicolas; De Brucker, Katrijn; Peeters, Annelies; Kucharíková, Soña; Gerits, Evelien; Verstraeten, Natalie; Michiels, Jan; Van Dijck, Patrick; Cammue, Bruno P A; Thevissen, Karin

    2014-12-01

    We here report on the in vitro activity of toremifene to inhibit biofilm formation of different fungal and bacterial pathogens, including Candida albicans, Candida glabrata, Candida dubliniensis, Candida krusei, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. We validated the in vivo efficacy of orally administered toremifene against C. albicans and S. aureus biofilm formation in a rat subcutaneous catheter model. Combined, our results demonstrate the potential of toremifene as a broad-spectrum oral antibiofilm compound. PMID:25288093

  13. The in vitro activity of vaginal Lactobacillus with probiotic properties against Candida.

    PubMed

    Strus, Magdalena; Kucharska, Agnieszka; Kukla, Grazyna; Brzychczy-Włoch, Monika; Maresz, Katarzyna; Heczko, Piotr B

    2005-06-01

    Lactobacilli, the predominant vaginal microorganisms in healthy premenopausal women, control other members of the vaginal microflora and thus protect against bacterial vaginosis and urinary tract infections. It has been claimed that some lactobacilli are also protective against Candida vaginitis. Little is known, however, about the mechanisms by which these lactobacilli can control vaginal populations of Candida and prevent vaginitis. To address this question, vaginal Lactobacillus strains with known antagonistic properties against bacteria were tested for their cell surface properties, adhesion to vaginal cell lines in vitro and antagonistic activities against Candida. A small proportion of the lactobacilli tested adhered strongly to cultured vaginal epithelial cells and inhibited growth of Candida albicans but not of C. pseudotropicalis. This anticandidal activity was in some Lactobacillus strains related to hydrogen peroxide (H2O2) production, but catalase treatment did not suppress this activity in other Lactobacillus strains, suggesting alternative mechanism(s). Moreover, tested vaginal Candida strains were resistant to relatively high concentrations of H2O2 that markedly exceeded those produced by even the most active Lactobacillus strains. PMID:16011996

  14. The in vitro activity of vaginal Lactobacillus with probiotic properties against Candida.

    PubMed Central

    Strus, Magdalena; Kucharska, Agnieszka; Kukla, Grazyna; Brzychczy-Włoch, Monika; Maresz, Katarzyna; Heczko, Piotr B

    2005-01-01

    Lactobacilli, the predominant vaginal microorganisms in healthy premenopausal women, control other members of the vaginal microflora and thus protect against bacterial vaginosis and urinary tract infections. It has been claimed that some lactobacilli are also protective against Candida vaginitis. Little is known, however, about the mechanisms by which these lactobacilli can control vaginal populations of Candida and prevent vaginitis. To address this question, vaginal Lactobacillus strains with known antagonistic properties against bacteria were tested for their cell surface properties, adhesion to vaginal cell lines in vitro and antagonistic activities against Candida. A small proportion of the lactobacilli tested adhered strongly to cultured vaginal epithelial cells and inhibited growth of Candida albicans but not of C. pseudotropicalis. This anticandidal activity was in some Lactobacillus strains related to hydrogen peroxide (H2O2) production, but catalase treatment did not suppress this activity in other Lactobacillus strains, suggesting alternative mechanism(s). Moreover, tested vaginal Candida strains were resistant to relatively high concentrations of H2O2 that markedly exceeded those produced by even the most active Lactobacillus strains. PMID:16011996

  15. In vitro avarol does affect the growth of Candida sp.

    PubMed

    Pejin, Boris; Ciric, Ana; Markovic, Dejan; Tommonaro, Giuseppina; Sokovic, Marina

    2016-09-01

    This work extends in vitro screening of antimicrobial activity of avarol, the marine natural product firstly isolated from the Mediterranean sponge Dysidea avara. Its anticandidial activity was evaluated by microdilution method against eight Candida strains, two ATCC and six clinical ones. At a different extent this compound was proven to be active against all the strains tested (MIC 0.8-6.0 μg/mL and MFC 1.6-12.0 μg/mL, respectively). According to the best of our knowledge, this is the first report on avarol activity towards any yeast strain which may be of relevance for Alzheimer's disease. Indeed, avarol derivatives showing moderate AChE activity should be screened for anticandidial activity both in vitro and in vivo. PMID:26405848

  16. Polyketide Glycosides from Bionectria ochroleuca Inhibit Candida albicans Biofilm Formation

    PubMed Central

    2015-01-01

    One of the challenges presented by Candida infections is that many of the isolates encountered in the clinic produce biofilms, which can decrease these pathogens’ susceptibilities to standard-of-care antibiotic therapies. Inhibitors of fungal biofilm formation offer a potential solution to counteracting some of the problems associated with Candida infections. A screening campaign utilizing samples from our fungal extract library revealed that a Bionectria ochroleuca isolate cultured on Cheerios breakfast cereal produced metabolites that blocked the in vitro formation of Candida albicans biofilms. A scale-up culture of the fungus was undertaken using mycobags (also known as mushroom bags or spawn bags), which afforded four known [TMC-151s C–F (1–4)] and three new [bionectriols B–D (5–7)] polyketide glycosides. All seven metabolites exhibited potent biofilm inhibition against C. albicans SC5314, as well as exerted synergistic antifungal activities in combination with amphotericin B. In this report, we describe the structure determination of the new metabolites, as well as compare the secondary metabolome profiles of fungi grown in flasks and mycobags. These studies demonstrate that mycobags offer a useful alternative to flask-based cultures for the preparative production of fungal secondary metabolites. PMID:25302529

  17. In vitro interactions between anidulafungin and nonsteroidal anti-inflammatory drugs on biofilms of Candida spp.

    PubMed

    Rosato, Antonio; Catalano, Alessia; Carocci, Alessia; Carrieri, Antonio; Carone, Addolorata; Caggiano, Giuseppina; Franchini, Carlo; Corbo, Filomena; Montagna, Maria Teresa

    2016-03-01

    Candida spp. are responsible for many biomaterial-related infections; they give rise to infective pathologies typically associated with biofilm formation. We recently reported that the echinocandin anidulafungin (ANF) showed a strong in vitro activity against both planktonic and biofilms cells. Herein, we report the antifungal activities of ANF alone and in association with some non-steroidal anti-inflammatory drugs (NSAIDs) against nine Candida strain biofilms: four Candida albicans, two Candida glabrata and three Candida guilliermondii. The activity of ANF was assessed using an in vitro microbiological model relevant for clinical practice. ANF proved oneself to be active against biofilms cells, and a clear-cut synergism was found against Candida species biofilms when ANF was used in combination with three NSAIDs: aspirin, diclofenac, ibuprofen. The positive synergism against Candida spp. of ANF in association with aspirin or the other NSAIDs proved to be a very effective antifungal treatment (FICI<0.5). These results may provide the starting point for new combination therapies of ANF with NSAIDs against Candida biofilm pathologies. PMID:26833243

  18. Praziquantel inhibits Schistosoma mansoni attachment in vitro.

    PubMed

    da-Silva, S P; Noel, F

    1990-01-01

    Male adult Schistosoma mansoni worms were placed in a glass dish containing Tyrode solution and observed for 15 min after addition of praziquantel (0.01 to 1 microM). Praziquantel promoted a concentration- and time-dependent inhibition of sucker-mediated attachment of the worm. Attachment inhibition was correlated with shortening of the parasite. We propose that the rapid and total inhibition of worm attachment observed in vitro with 1 microM praziquantel indicates that therapeutic concentrations of this drug should promote a rapid hepatic shift, in vivo, which may facilitate host tissue reaction. PMID:2101049

  19. Histone Deacetylases and Their Inhibition in Candida Species.

    PubMed

    Garnaud, Cécile; Champleboux, Morgane; Maubon, Danièle; Cornet, Muriel; Govin, Jérôme

    2016-01-01

    Fungi are generally benign members of the human mucosal flora or live as saprophytes in the environment. However, they can become pathogenic, leading to invasive and life threatening infections in vulnerable patients. These invasive fungal infections are regarded as a major public health problem on a similar scale to tuberculosis or malaria. Current treatment for these infections is based on only four available drug classes. This limited therapeutic arsenal and the emergence of drug-resistant strains are a matter of concern due to the growing number of patients to be treated, and new therapeutic strategies are urgently needed. Adaptation of fungi to drug pressure involves transcriptional regulation, in which chromatin dynamics and histone modifications play a major role. Histone deacetylases (HDACs) remove acetyl groups from histones and actively participate in controlling stress responses. HDAC inhibition has been shown to limit fungal development, virulence, biofilm formation, and dissemination in the infected host, while also improving the efficacy of existing antifungal drugs toward Candida spp. In this article, we review the functional roles of HDACs and the biological effects of HDAC inhibitors on Candida spp., highlighting the correlations between their pathogenic effects in vitro and in vivo. We focus on how HDAC inhibitors could be used to treat invasive candidiasis while also reviewing recent developments in their clinical evaluation. PMID:27547205

  20. Histone Deacetylases and Their Inhibition in Candida Species

    PubMed Central

    Garnaud, Cécile; Champleboux, Morgane; Maubon, Danièle; Cornet, Muriel; Govin, Jérôme

    2016-01-01

    Fungi are generally benign members of the human mucosal flora or live as saprophytes in the environment. However, they can become pathogenic, leading to invasive and life threatening infections in vulnerable patients. These invasive fungal infections are regarded as a major public health problem on a similar scale to tuberculosis or malaria. Current treatment for these infections is based on only four available drug classes. This limited therapeutic arsenal and the emergence of drug-resistant strains are a matter of concern due to the growing number of patients to be treated, and new therapeutic strategies are urgently needed. Adaptation of fungi to drug pressure involves transcriptional regulation, in which chromatin dynamics and histone modifications play a major role. Histone deacetylases (HDACs) remove acetyl groups from histones and actively participate in controlling stress responses. HDAC inhibition has been shown to limit fungal development, virulence, biofilm formation, and dissemination in the infected host, while also improving the efficacy of existing antifungal drugs toward Candida spp. In this article, we review the functional roles of HDACs and the biological effects of HDAC inhibitors on Candida spp., highlighting the correlations between their pathogenic effects in vitro and in vivo. We focus on how HDAC inhibitors could be used to treat invasive candidiasis while also reviewing recent developments in their clinical evaluation. PMID:27547205

  1. Miltefosine is effective against Candida albicans and Fusarium oxysporum nail biofilms in vitro.

    PubMed

    Machado Vila, Taissa Vieira; Sousa Quintanilha, Natália; Rozental, Sonia

    2015-11-01

    Onychomycosis is a fungal nail infection that represents ∼50 % of all nail disease cases worldwide. Clinical treatment with standard antifungals frequently requires long-term systemic therapy to avoid chronic disease. Onychomycosis caused by non-dermatophyte moulds, such as Fusarium spp., and yeasts, such as Candida spp., is particularly difficult to treat, possibly due to the formation of drug-resistant fungal biofilms on affected areas. Here, we show that the alkylphospholipid miltefosine, used clinically against leishmaniasis and cutaneous breast metastases, has potent activity against biofilms of Fusarium oxysporum and Candida albicans formed on human nail fragments in vitro. Miltefosine activity was compared with that of commercially available antifungals in the treatment of biofilms at two distinct developmental phases: formation and maturation (pre-formed biofilms). Drug activity towards biofilms formed on nail fragments and on microplate surfaces (microdilution assays) was evaluated using XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] assays, and drug effects on fingernail biofilms were analysed by scanning electron microscopy (SEM). For F. oxysporum, miltefosine at 8 μg ml- 1 inhibited biofilm formation by 93%, whilst 256 μg ml- 1 reduced the metabolic activity of pre-formed nail biofilms by 93%. Treatment with miltefosine at 1000 μg ml- 1 inhibited biofilm formation by 89% and reduced the metabolic activity of pre-formed C. albicans biofilms by 99%. SEM analyses of biofilms formed on fingernail fragments showed a clear reduction in biofilm biomass after miltefosine treatment, in agreement with XTT results. Our results show that miltefosine has potential as a therapeutic agent against onychomycosis and should be considered for in vivo efficacy studies, especially in topical formulations for refractory disease treatment. PMID:26404553

  2. In vitro activities of natural products against oral Candida isolates from denture wearers

    PubMed Central

    2011-01-01

    Background Candida-associated denture stomatitis is a frequent infectious disease. Treatment of this oral condition is difficult because failures and recurrences are common. The aim of this study was to test the in vitro antifungal activity of pure constituents of essentials oils. Methods Eight terpenic derivatives (carvacrol, farnesol, geraniol, linalool, menthol, menthone, terpinen-4-ol, and α-terpineol), a phenylpropanoid (eugenol), a phenethyl alcohol (tyrosol) and fluconazole were evaluated against 38 Candida isolated from denture-wearers and 10 collection Candida strains by the CLSI M27-A3 broth microdilution method. Results Almost all the tested compounds showed antifungal activity with MIC ranges of 0.03-0.25% for eugenol and linalool, 0.03-0.12% for geraniol, 0.06-0.5% for menthol, α-terpineol and terpinen-4-ol, 0.03-0.5% for carvacrol, and 0.06-4% for menthone. These compounds, with the exception of farnesol, menthone and tyrosol, showed important in vitro activities against the fluconazole-resistant and susceptible-dose dependent Candida isolates. Conclusions Carvacrol, eugenol, geraniol, linalool and terpinen-4-ol were very active in vitro against oral Candida isolates. Their fungistatic and fungicidal activities might convert them into promising alternatives for the topic treatment of oral candidiasis and denture stomatitis. PMID:22118215

  3. [In vitro nystatin sensitivity of vaginal isolates of Candida spp].

    PubMed

    Andreu, C M; Medina, Y E; Gonzáles, T C; Llanes, D M

    2001-01-01

    The minimum inhibitory concentration (MIC) of nistatine, one of the most used antifungal agents for this micosis, was determined in 68 Candida strains isolated from vaginal smears. Candida albicans represented 75% of the total strains whereas C. parapsilosis, C. krusei and C. glabrata were much less frequently found. The predisposing factors were pregnancy and antibacterial treatment whereas leukorrhea and itching were the prevailing symptoms in most of the cases. MIC values from the use of a broth dilution method ranged from 0,5-8mg/mL and the geometric mean was 1.36mg/ mL. For C. albicans, MIC was 4mg/mL due to two strains that showed the highest MIC values (8 mg/mL). Similarly, the strains showed low MIC values, this means that therapeutic failures are not inherent to the emergence of resistant strains. PMID:15846923

  4. Ocimum sanctum essential oil inhibits virulence attributes in Candida albicans.

    PubMed

    Khan, Amber; Ahmad, Aijaz; Xess, Immaculata; Khan, Luqman A; Manzoor, Nikhat

    2014-03-15

    Candida albicans is an opportunistic human fungal pathogen which causes disease mainly in immunocompromised patients. Activity of hydrolytic enzymes is essential for virulence of C. albicans and so is the capacity of these cells to undergo transition from yeast to mycelial form of growth. Ocimum sanctum is cultivated worldwide for its essential oil which exhibits medicinal properties. This work evaluates the anti-virulence activity of O. sanctum essential oil (OSEO) on 22 strains of C. albicans (including a standard strain ATCC 90028) isolated from both HIV positive and HIV negative patients. Candida isolates were exposed to sub-MICs of OSEO. In vitro secretion of proteinases and phospholipases was evaluated by plate assay containing BSA and egg yolk respectively. Morphological transition from yeast to filamentous form was monitored microscopically in LSM. For genetic analysis, respective genes associated with morphological transition (HWP1), proteinase (SAP1) and phospholipase (PLB2) were also investigated by Real Time PCR (qRT-PCR). Results were analyzed using Student's t-test. OSEO inhibits morphological transition in C. albicans and had a significant inhibitory effect on extracellular secretion of proteinases and phospholipases. Expression profile of respective selected genes associated with C. albicans virulence by qRT-PCR showed a reduced expression of HWP1, SAP1 and PLB2 genes in cells treated with sub-inhibitory concentrations of OSEO. This work suggests that OSEO inhibits morphological transition in C. albicans and decreases the secretion of hydrolytic enzymes involved in the early stage of infection as well as down regulates the associated genes. Further studies will assess the clinical application of OSEO and its constituents in the treatment of fungal infections. PMID:24252340

  5. In Vitro and In Vivo Activity of a Novel Antifungal Small Molecule against Candida Infections

    PubMed Central

    Yuen, Kwok Yong; Wang, Yu; Yang, Dan; Samaranayake, Lakshman Perera

    2014-01-01

    Candida is the most common fungal pathogen of humans worldwide and has become a major clinical problem because of the growing number of immunocompromised patients, who are susceptible to infection. Moreover, the number of available antifungals is limited, and antifungal-resistant Candida strains are emerging. New and effective antifungals are therefore urgently needed. Here, we discovered a small molecule with activity against Candida spp. both in vitro and in vivo. We screened a library of 50,240 small molecules for inhibitors of yeast-to-hypha transition, a major virulence attribute of Candida albicans. This screening identified 20 active compounds. Further examination of the in vitro antifungal and anti-biofilm properties of these compounds, using a range of Candida spp., led to the discovery of SM21, a highly potent antifungal molecule (minimum inhibitory concentration (MIC) 0.2 – 1.6 µg/ml). In vitro, SM21 was toxic to fungi but not to various human cell lines or bacterial species and was active against Candida isolates that are resistant to existing antifungal agents. Moreover, SM21 was relatively more effective against biofilms of Candida spp. than the current antifungal agents. In vivo, SM21 prevented the death of mice in a systemic candidiasis model and was also more effective than the common antifungal nystatin at reducing the extent of tongue lesions in a mouse model of oral candidiasis. Propidium iodide uptake assay showed that SM21 affected the integrity of the cell membrane. Taken together, our results indicate that SM21 has the potential to be developed as a novel antifungal agent for clinical use. PMID:24465737

  6. In vitro activity of Caspofungin combined with Fluconazole on mixed Candida albicans and Candida glabrata biofilm.

    PubMed

    Pesee, Siripen; Angkananuwat, Chayanit; Tancharoensukjit, Sudarat; Muanmai, Somporn; Sirivan, Pattaraporn; Bubphawas, Manita; Tanarerkchai, Nissara

    2016-05-01

    The objective of this study was to evaluate the antifungal effect of caspofungin (CAS) combined with fluconazole (FLU) on the biofilm biomass and cultivable viability and microstructure ofCandida albicansandCandida glabratamixed biofilmin vitro.Biofilms were formed in a 96-well microtiter plate for crystal violet assay and colony forming unit (CFU) method and grown on plastic coverslip disks for scanning electron microscopy. MIC50of CAS and FLU against singleCandida spp.and mixedCandida spp.biofilms were evaluated using crystal violet assay. Additional,C. albicansandC. glabratamixed biofilms were incubated with subinhibitory CAS concentration plus FLU and their percentages ofCandidabiofilm reduction were calculated. We found that percentages of biofilm reduction were significantly decreased when CAS at 0.25MIC and FLU (0.25 or 0.5MIC) were combined (P< .05) but not different when CAS at 0.5 MIC combined with FLU at 0.25 or 0.5MIC, compared to CAS treatment alone. Structural analyses revealed that CAS/FLU combination-treated biofilms showed less hyphae and blastospores with some aberrant cells compared to control group. Although it was evident that a greater CFU ofCandida glabratawere demonstrated in every group, the total viable cells derived from CAS/FLU combination-treated biofilms at any ratio were not significantly different from positive control. Overall, CAS/FLU combinations appeared to affect the quantity and cell architecture, but number of viable cell, ofCandida albicansandCandida glabratamixed biofilm. This antifungal effect was CAS concentration dependent. PMID:26768371

  7. In Vitro Analysis of Finasteride Activity against Candida albicans Urinary Biofilm Formation and Filamentation

    PubMed Central

    Chavez-Dozal, Alba A.; Lown, Livia; Jahng, Maximillian; Walraven, Carla J.

    2014-01-01

    Candida albicans is the 3rd most common cause of catheter-associated urinary tract infections, with a strong propensity to form drug-resistant catheter-related biofilms. Due to the limited efficacy of available antifungals against biofilms, drug repurposing has been investigated in order to identify novel agents with activities against fungal biofilms. Finasteride is a 5-α-reductase inhibitor commonly used for the treatment of benign prostatic hyperplasia, with activity against human type II and III isoenzymes. We analyzed the Candida Genome Database and identified a C. albicans homolog of type III 5-α-reductase, Dfg10p, which shares 27% sequence identity and 41% similarity to the human type III 5-α-reductase. Thus, we investigated finasteride for activity against C. albicans urinary biofilms, alone and in combination with amphotericin B or fluconazole. Finasteride alone was highly effective in the prevention of C. albicans biofilm formation at doses of ≥16 mg/liter and the treatment of preformed biofilms at doses of ≥128 mg/liter. In biofilm checkerboard analyses, finasteride exhibited synergistic activity in the prevention of biofilm formation in a combination of 4 mg/liter finasteride with 2 mg/liter fluconazole. Finasteride inhibited filamentation, thus suggesting a potential mechanism of action. These results indicate that finasteride alone is highly active in the prevention of C. albicans urinary biofilms in vitro and has synergistic activity in combination with fluconazole. Further investigation of the clinical utility of finasteride in the prevention of urinary candidiasis is warranted. PMID:25049253

  8. In vitro biofilm production of Candida bloodstream isolates: any association with clinical characteristics?

    PubMed

    Pongrácz, Júlia; Benedek, Kálmán; Juhász, Emese; Iván, Miklós; Kristóf, Katalin

    2016-04-01

    Candida spp. are a leading cause of bloodstream infection (BSI) and are associated with high mortality rates. Biofilm production is a virulence factor of Candida spp., and has been linked with poor clinical outcome. The aim of our study was to assess biofilm production of Candida bloodstream isolates at our institute, and to determine whether in vitro biofilm production is associated with any clinical characteristics of infection. During the four-year study period, 93 cases of Candida BSI were analysed. The most frequently isolated species was C. albicans (66.7 %), followed by C. glabrata (9.7 %), C. parapsilosis (9.7 %), C. tropicalis (9.7 %) and C. krusei (4.3 %). Biofilm production was more prevalent among non-albicans Candida spp. (77.4 %) than C. albicans (30.6 %) (P = 0.02). Abdominal surgery was identified as a risk factor of BSI caused by biofilm producing non-albicans Candida isolates. No risk factors predisposing to bloodstream infection caused by a biofilm producing C. albicans isolate were identified. Biofilm production was not verified as a risk factor of mortality. PMID:26678484

  9. Comparison of the in vitro Effect of Chemical and Herbal Mouthwashes on Candida albicans

    PubMed Central

    Talebi, Somayeh; Sabokbar, Azar; Riazipour, Majid; Saffari, Mohsen

    2014-01-01

    Background: During the recent decades research has focused to find scientific evidence for the effects of herbal medicines. Researchers are interested in herbal remedies for medication and aim to substitute herbal material instead of chemical formula with limited side effects for human being. Objectives: The aim of the current study was to compare the in vitro effect of herbal and chemical mouthwashes against Candida albicans. Materials and Methods: In this research, we used a standard strain of C. albicans, PTCC 5027. The suspension was made by a fresh culture of C. albicans (24 hours) and the optical density (turbidity equating to a McFarland standard of 0.5) was read at 530 nm. The C. albicans suspension was cultured on Sabouraud dextrose agar plate. Next, two wells were filled with mouthwashes and after incubation at 30ºC for 24 hours, the inhibition zone was measured. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of mouthwashes were determined. Data were analyzed using the SPSS software, independent T-tests and one-sided variance analysis (ANOVA-one way). Results: Based on these findings on agar diffusion with (P = 0.764), MIC and MFC tests (P = 0.879), there were no significant differences between the antifungal effect of herbal and chemical mouthwashes. Conclusions: This study showed that, chemical mouthwashes acted better than herbal mouthwashes and among different chemical mouthwashes, Oral B was most effective. PMID:25741429

  10. In Vitro and In Vivo Activities of Pterostilbene against Candida albicans Biofilms

    PubMed Central

    Li, De-Dong; Zhao, Lan-Xue; Mylonakis, Eleftherios; Hu, Gan-Hai; Zou, Yong; Huang, Tong-Kun; Yan, Lan

    2014-01-01

    Pterostilbene (PTE) is a stilbene-derived phytoalexin that originates from several natural plant sources. In this study, we evaluated the activity of PTE against Candida albicans biofilms and explored the underlying mechanisms. In 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assays, biofilm biomass measurement, confocal laser scanning microscopy, and scanning electron microscopy, we found that ≤16 μg/ml PTE had a significant effect against C. albicans biofilms in vitro, while it had no fungicidal effect on planktonic C. albicans cells, which suggested a unique antibiofilm effect of PTE. Then we found that PTE could inhibit biofilm formation and destroy the maintenance of mature biofilms. At 4 μg/ml, PTE decreased cellular surface hydrophobicity (CSH) and suppressed hyphal formation. Gene expression microarrays and real-time reverse transcription-PCR showed that exposure of C. albicans to 16 μg/ml PTE altered the expression of genes that function in morphological transition, ergosterol biosynthesis, oxidoreductase activity, and cell surface and protein unfolding processes (heat shock proteins). Filamentation-related genes, especially those regulated by the Ras/cyclic AMP (cAMP) pathway, including ECE1, ALS3, HWP1, HGC1, and RAS1 itself, were downregulated upon PTE treatment, indicating that the antibiofilm effect of PTE was related to the Ras/cAMP pathway. Then, we found that the addition of exogenous cAMP reverted the PTE-induced filamentous growth defect. Finally, with a rat central venous catheter infection model, we confirmed the in vivo activity of PTE against C. albicans biofilms. Collectively, PTE had strong activities against C. albicans biofilms both in vitro and in vivo, and these activities were associated with the Ras/cAMP pathway. PMID:24514088

  11. Oxidative stress of photodynamic antimicrobial chemotherapy inhibits Candida albicans virulence

    NASA Astrophysics Data System (ADS)

    Kato, Ilka Tiemy; Prates, Renato Araujo; Tegos, George P.; Hamblin, Michael R.; Simões Ribeiro, Martha

    2011-03-01

    Photodynamic antimicrobial chemotherapy (PACT) is based on the principal that microorganisms will be inactivated using a light source combined to a photosensitizing agent in the presence of oxygen. Oxidative damage of cell components occurs by the action of reactive oxygen species leading to cell death for microbial species. It has been demonstrated that PACT is highly efficient in vitro against a wide range of pathogens, however, there is limited information for its in vivo potential. In addition, it has been demonstrated that sublethal photodynamic inactivation may alter the virulence determinants of microorganisms. In this study, we explored the effect of sublethal photodynamic inactivation to the virulence factors of Candida albicans. Methylene Blue (MB) was used as photosensitizer for sublethal photodynamic challenge on C. albicans associated with a diode laser irradiation (λ=660nm). The parameters of irradiation were selected in causing no reduction of viable cells. The potential effects of PACT on virulence determinants of C. albicans cells were investigated by analysis of germ tube formation and in vivo pathogenicity assays. Systemic infection was induced in mice by the injection of fungal suspension in the lateral caudal vein. C. albicans exposed to sublethal photodynamic inactivation formed significantly less germ tube than untreated cells. In addition, mice infected with C. albicans submitted to sublethal PACT survived for a longer period of time than mice infected with untreated cells. The oxidative damage promoted by sublethal photodynamic inactivation inhibited virulence determinants and reduced in vivo pathogenicity of C. albicans.

  12. In Vitro Activity of Tea Tree Oil Vaginal Suppositories against Candida spp. and Probiotic Vaginal Microbiota.

    PubMed

    Di Vito, Maura; Mattarelli, Paola; Modesto, Monica; Girolamo, Antonietta; Ballardini, Milva; Tamburro, Annunziata; Meledandri, Marcello; Mondello, Francesca

    2015-10-01

    The aim of this work is to evaluate the in vitro microbicidal activity of vaginal suppositories (VS) containing tea tree oil (TTO-VS) towards Candida spp. and vaginal probiotics. A total of 20 Candida spp. strains, taken from patients with vaginitis and from an established type collection, including reference strains, were analysed by using the CLSI microdilution method. To study the action of VS towards the beneficial vaginal microbiota, the sensitivity of Bifidobacterium animalis subsp. lactis (DSM 10140) and Lactobacillus spp. (Lactobacillus casei R-215 and Lactobacillus acidophilus R-52) was tested. Both TTO-VS and TTO showed fungicidal activity against all strains of Candida spp. whereas placebo-VS or the Aloe gel used as controls were ineffective. The study of fractional fungicidal concentrations (FFC) showed synergistic interaction with the association between Amphotericin B and TTO (0.25 to 0.08 µg/ml, respectively) against Candida albicans. Instead, the probiotics were only affected by TTO concentration ≥ 4% v/v, while, at concentrations < 2% v/v, they remained viable. TTO-VS exhibits, in vitro, a selective fungicidal action, slightly affecting only the Bifidobacteriun animalis strain growth belonging to the vaginal microbiota. In vivo studies are needed to confirm the efficacy to prevent acute or recurrent vaginal candidiasis. PMID:26235937

  13. Phytic Acid Inhibits Lipid Peroxidation In Vitro

    PubMed Central

    Węglarz, Ludmiła; Dzierżewicz, Zofia

    2013-01-01

    Phytic acid (PA) has been recognized as a potent antioxidant and inhibitor of iron-catalyzed hydroxyl radical formation under in vitro and in vivo conditions. Therefore, the aim of the present study was to investigate, with the use of HPLC/MS/MS, whether PA is capable of inhibiting linoleic acid autoxidation and Fe(II)/ascorbate-induced peroxidation, as well as Fe(II)/ascorbate-induced lipid peroxidation in human colonic epithelial cells. PA at 100 μM and 500 μM effectively inhibited the decay of linoleic acid, both in the absence and presence of Fe(II)/ascorbate. The observed inhibitory effect of PA on Fe(II)/ascorbate-induced lipid peroxidation was lower (10–20%) compared to that of autoxidation. PA did not change linoleic acid hydroperoxides concentration levels after 24 hours of Fe(II)/ascorbate-induced peroxidation. In the absence of Fe(II)/ascorbate, PA at 100 μM and 500 μM significantly suppressed decomposition of linoleic acid hydroperoxides. Moreover, PA at the tested nontoxic concentrations (100 μM and 500 μM) significantly decreased 4-hydroxyalkenal levels in Caco-2 cells which structurally and functionally resemble the small intestinal epithelium. It is concluded that PA inhibits linoleic acid oxidation and reduces the formation of 4-hydroxyalkenals. Acting as an antioxidant it may help to prevent intestinal diseases induced by oxygen radicals and lipid peroxidation products. PMID:24260736

  14. In vitro investigations on the mode of action of the hydroxypyridone antimycotics rilopirox and piroctone on Candida albicans.

    PubMed

    Sigle, H C; Schäfer-Korting, M; Korting, H C; Hube, B; Niewerth, M

    2006-05-01

    Rilopirox and piroctone belong to the class of hydroxypyridone antimycotics. This class is not related to other antimycotics. In contrast to azole antimycotics and polyene antimycotics the mode of action of hydroxypyridone antimycotics is not fully understood. Inhibition of cellular uptake of essential compounds as well as loss of other compounds seems to be only a secondary effect of a primary not known action of these drugs. The antifungal effect in vitro depends on the medium used. The hyphal induction of Candida albicans is inhibited by hydroxypyridone antimycotics, but this effect is compensated by iron ions. A damage of the cell membrane and a direct influence on adenosine triphosphate synthesis, respectively, do not seem to be part of the mode of action. But there are clear hints that reactive oxygen species (ROS) and available metabolic activity are important parts of the mode of action of the hydroxypyridone antimycotics rilopirox and piroctone. PMID:16681805

  15. Inhibition of dioscin on Saprolegnia in vitro.

    PubMed

    Liu, Lei; Shen, Yu-Feng; Liu, Guang-Lu; Ling, Fei; Liu, Xin-Yang; Hu, Kun; Yang, Xian-Le; Wang, Gao-Xue

    2015-12-01

    As one of the most serious pathogens in the freshwater aquatic environment, Saprolegnia can induce a high mortality rate during the fish egg incubation period. This study investigated the anti-Saprolegnia activity of a total of 108 plants on Saprolegnia parasitica in vitro and Dioscorea collettii was selected for further studies. By loading on an open silica gel column and eluting with petroleum ether-ethyl acetate-methanol, dioscin (C45H72O16) was isolated from D. collettii. Saprolegnia parasitica growth was inhibited significantly when dioscin concentration was more than 2.0 mg L(-1). When compared with formalin and hydrogen peroxide, dioscin showed a higher inhibitory effect. As potential inhibition mechanisms, dioscin could cause the S. parasitica mycelium morphologic damage, dense folds, or disheveled protuberances observed by field emission scanning electron microscopy and the influx of Propidium iodide. The structural changes in the treated mycelium were indicative of an efficient anti-Saprolegnia activity of dioscin. The oxidative stress results showed that dioscin also accumulated reactive oxygen species excessively and increased total antioxidant and superoxide dismutase activity. These situations could render S. parasitica more vulnerable to oxidative damage. Additionally, when dioscin concentration was less than 2.0 mg L(-1), the survival rate of embryos was more than 70%. Therefore, the use of dioscin could be a viable way of preventing and controlling saprolegniasis. PMID:26472687

  16. Damage to Candida albicans Hyphae and Pseudohyphae by the Myeloperoxidase System and Oxidative Products of Neutrophil Metabolism In Vitro

    PubMed Central

    Diamond, Richard D.; Clark, Robert A.; Haudenschild, Christian C.

    1980-01-01

    In previous studies, we noted that Candida hyphae and pseudohyphae could be damaged and probably killed by neutrophils, primarily by oxygen-dependent nonphagocytic mechanisms. In extending these studies, amount of damage to hyphae again was measured by inhibition of [14C]cytosine uptake. Neutrophils from only one of four patients with chronic granulomatous disease damaged hyphae at all, and neutrophils from this single patient damaged hyphae far less efficiently than simultaneously tested neutrophils from normal control subjects. Neutrophils from neither of two subjects with hereditary myeloperoxidase deficiency damaged the hyphae. This confirmed the importance of oxidative mechanisms in general and myeloperoxidase-mediated systems in particular in damaging Candida hyphae. Several potentially fungicidal oxidative intermediates are produced by metabolic pathways of normal neutrophils, but their relative toxicity for Candida hyphae was previously unknown. To help determine this, cell-free in vitro systems were used to generate these potentially microbicidal products. Myeloperoxidase with hydrogen peroxide, iodide, and chloride resulted in 91.2% damage to hyphal inocula in 11 experiments. There was less damage when either chloride or iodide was omitted, and no damage when myeloperoxidase was omitted or inactivated by heating. Azide, cyanide, and catalase (but not heated catalase) inhibited the damage. Systems for generation of hydrogen peroxide could replace reagent hydrogen peroxide in the myeloperoxidase system. These included glucose oxidase, in the presence of glucose, and xanthine oxidase, in the presence of either hypoxanthine or acetaldehyde. In the presence of myeloperoxidase and a halide, the toxicity of the xanthine oxidase system was not inhibited by superoxide dismutase and, under some conditions, was marginally increased by this enzyme. This suggested that superoxide radical did not damage hyphae directly but served primarily as an intermediate in the

  17. Species Distribution and In Vitro Antifungal Susceptibility of Vulvovaginal Candida Isolates in China

    PubMed Central

    Wang, Feng-Juan; Zhang, Dai; Liu, Zhao-Hui; Wu, Wen-Xiang; Bai, Hui-Hui; Dong, Han-Yu

    2016-01-01

    Background: Vulvovaginal candidiasis (VVC) was a common infection associated with lifelong harassment of woman's social and sexual life. The purpose of this study was to describe the species distribution and in vitro antifungal susceptibility of Candida species (Candida spp.) isolated from patients with VVC over 8 years. Methods: Species which isolated from patients with VVC in Peking University First Hospital were identified using chromogenic culture media. Susceptibility to common antifungal agents was determined using agar diffusion method based on CLSI M44-A2 document. SPSS software (version 14.0, Inc., Chicago, IL, USA) was used for statistical analysis, involving statistical description and Chi-square test. Results: The most common strains were Candida (C.) albicans, 80.5% (n = 1775) followed by C. glabrata, 18.1% (n = 400). Nystatin exhibited excellent activity against all species (<4% resistant [R]). Resistance to azole drugs varied among different species. C. albicans: clotrimazole (3.1% R) < fluconazole (16.6% R) < itraconazole (51.5% R) < miconazole (54.0% R); C. glabrata: miconazole (25.6% R) < clotrimazole (50.5% R) < itraconazole (61.9% R) < fluconazole (73.3% R); Candida krusei: clotrimazole (0 R) < fluconazole (57.7% R) < miconazole (73.1% R) < itraconazole (83.3% R). The susceptibility of fluconazole was noticeably decreasing among all species in the study period. Conclusions: Nystatin was the optimal choice for the treatment of VVC at present. The species distribution and in vitro antifungal susceptibility of Candida spp. isolated from patients with VVC had changed over time. PMID:27174323

  18. Inhibitory activity in vitro of probiotic lactobacilli against oral Candida under different fermentation conditions.

    PubMed

    Jiang, Q; Stamatova, I; Kari, K; Meurman, J H

    2015-01-01

    Clinical studies have shown that probiotics positively affect oral health by decreasing gum bleeding and/or reducing salivary counts of certain oral pathogens. Our aim was to investigate the inhibitory effect of six probiotic lactobacilli against opportunistic oral Candida species. Sugar utilisation by both lactobacilli and Candida was also assessed. Agar overlay assay was utilised to study growth inhibition of Candida albicans, Candida glabrata and Candida krusei by Lactobacillus rhamnosus GG, Lactobacillus casei Shirota, Lactobacillus reuteri SD2112, Lactobacillus brevis CD2, Lactobacillus bulgaricus LB86 and L. bulgaricus LB Lact. The inhibitory effect was measured at pH 5.5, 6.4, and 7.2, respectively, and in the presence of five different carbohydrates in growth medium (glucose, fructose, lactose, sucrose, and sorbitol). Growth and final pH values were measured at two-hour time points to 24 h. L. rhamnosus GG showed the strongest inhibitory activity in fructose and glucose medium against C. albicans, followed by L. casei Shirota, L. reuteri SD2112 and L. brevis CD2. None of the lactobacilli tested affected the growth of C. krusei. Only L. rhamnosus GG produced slight inhibitory effect on C. glabrata. The lower pH values led to larger inhibition zones. Sugar fermentation profiles varied between the strains. L. casei Shirota grew in the presence of all sugars tested, whereas L. brevis CD2 could utilise only glucose and fructose. All Candida species metabolised the available sugars but the most rapid growth was observed with C. glabrata. The results suggest that commercially available probiotics differ in their inhibitory activity and carbohydrate utilisation; the above properties are modified by different pH values and sugars with more pronounced inhibition at lower pH. PMID:25380800

  19. Effectiveness of Photodynamic Therapy for the Inactivation of Candida spp. on Dentures: In Vitro Study

    PubMed Central

    Mima, Ewerton Garcia de Oliveira; Ribeiro, Daniela Garcia; Dovigo, Livia Nordi; Vergani, Carlos Eduardo; Bagnato, Vanderlei Salvador

    2011-01-01

    Abstract Objective: This in vitro study evaluated the effectiveness of photodynamic therapy (PDT) for the inactivation of different species of Candida on maxillary complete dentures. Background data: The treatment of denture stomatitis requires the inactivation of Candida spp. on dentures. PDT has been reported as an effective method for Candida inactivation. Methods: Reference strains of C. albicans, C. glabrata, C. tropicalis, C. dubliniensis and C. krusei were tested. Thirty-four dentures were fabricated in a standardized procedure and subjected to ethylene oxide sterilization. The dentures were individually inoculated with one of the strains and incubated at 37°C for 24 h. Dentures submitted to PDT (P+L+) were individually sprayed with 50 mg/L of Photogem® (PS) and, after 30 min, illuminated by LED light for 26 min (37.5 J/cm2). Additional dentures were treated only with PS (P+L-) or light (P-L+) or neither (P-L-). Samples of serial dilutions were spread on Sabouraud dextrose agar and incubated at 37°C for 48 h. The colonies were counted and the values of log (cfu/mL) were analyzed by Kruskall-Wallis and Dunn tests (p<0.05). Results: For all species of Candida, PDT resulted in significant reduction (p<0.05) of cfu/mL values from dentures when compared with P-L- (reductions from 1.73 to 3.99 log10). Significant differences (p<0.05), but lower reductions, were also observed for P+L- and P-L+when compared with P-L- for some species of Candida. Conclusions: PDT was an effective method for reducing Candida spp. on dentures. PMID:21916614

  20. The influence of photodynamic therapy parameters on the inactivation of Candida spp: in vitro and in vivo studies

    NASA Astrophysics Data System (ADS)

    Alves, F.; Mima, E. G.; Dovigo, L. N.; Bagnato, V. S.; Jorge, J. H.; de Souza Costa, C. A.; Pavarina, A. C.

    2014-04-01

    The influence of parameters of photodynamic therapy (PDT), such as pre-irradiation time (PIT), on the inactivation of Candida spp. was assessed in vitro and in vivo. Suspensions of Candida albicans, Candida tropicalis, Candida krusei and Candida glabrata were treated with Photogem®, incubated for 5, 10 or 15 min and illuminated with a blue LED light. Colonies were cultivated and log values of CFU ml-1 were analyzed by ANOVA and Kruskall-Wallis test. For in vivo evaluation, immunosuppressed mice were inoculated with C. albicans. PDT was performed on the dorsum of the tongue by topical administration of Photogem® and illumination after 5, 10 or 15 min. C. albicans was recovered from the tongue and the number of CFU ml-1 was analyzed by ANOVA and Tukey test. Animals were killed and the tongues were surgically removed for histological analysis. Susceptibility of Candida spp. suspensions to PDT was in decreasing order: C. albicans = C. tropicalis < C. krusei < C. glabrata. No significant difference was observed among the different PIT (p > 0.05), both in vivo and in vitro. A significant reduction (p < 0.05) of log(CFU ml-1) of C. albicans from tongues of mice was observed with no adverse effects in the tissue. PDT was effective to inactivate in vitroCandida spp. and for reduction of C. albicans in vivo, independently of the PIT used.

  1. In vitro effects of glycyrrhetinic acid on the growth of clinical isolates of Candida albicans.

    PubMed

    Pellati, Donatella; Fiore, Cristina; Armanini, Decio; Rassu, Mario; Bertoloni, Giulio

    2009-04-01

    Compounds derived from Glycyrrhiza glabra L. root have been used widely for centuries for their numerous therapeutic properties. The present study aimed to test the in vitro activity against Candida albicans strains of the compound 18-beta glycyrrhetinic acid (18-beta GA), derived from the root of Glycyrrhiza species. This antimicrobial activity was assessed using the National Committee for Clinical Laboratory Standards (NCCLS) method on C. albicans strains that were isolated from patients with recurrent vulvovaginal candidiasis (RVVC). The in vitro growth of the C. albicans strains was markedly reduced, in a pH-dependent manner, by relatively low doses (6.2 microg/mL) of 18-beta GA. The results demonstrate that 18-beta GA is a promising biological alternative for the topical treatment of recurrent vulvovaginal candidiasis (RVVC). PMID:19067381

  2. Metoclopramide inhibits aldosterone biosynthesis in vitro.

    PubMed

    Lauer, C G; Braley, L M; Menachery, A I; Williams, G H

    1982-07-01

    Metoclopramide, a dopaminergic antagonist, has consistently elevated plasma aldosterone levels in vivo. To determine whether this was a direct action of metoclopramide on adrenal steroidogenesis, we examined the response of collagenase-dispersed rat adrenal glomerulosa cells to metoclopramide in vitro. The effect of increasing concentrations of metoclopramide (3 X 10(-10) to 3 X 10(-4) M) on basal as well as angiotensin II (2.4 X 10(-10) to 2.4 X 10(-8) M)-, ACTH (3.5 X 10(-11) M)- and potassium (5.9 meq/liter)-stimulated aldosterone production was evaluated. Metoclopramide caused a dose-related decrease in basal and stimulated aldosterone production (P less than 0.01). In addition, metoclopramide also blocked basal and stimulated corticosterone production (P less than 0.01). This was not due to an irreversible toxic effect, since glomerulosa cells preincubated with 3 X 10(-4) M metoclopramide excluded trypan blue dye and responded to ACTH stimulation. Sodium metabisulfite, an antioxidant present in the metoclopramide preparation, did not contribute to the metoclopramide effect. These results indicate that metoclopramide is an aldosterone antagonist in vitro, contrary to reported data obtained in vivo. Thus, metoclopramide may be a partial dopaminergic agonist: in vitro where dopamine levels are negligible, it is an agonist, whereas in vivo where dopamine concentrations are greater, it is an antagonist. PMID:6282568

  3. Effect of Streptococcus salivarius K12 on the in vitro growth of Candida albicans and its protective effect in an oral candidiasis model.

    PubMed

    Ishijima, Sanae A; Hayama, Kazumi; Burton, Jeremy P; Reid, Gregor; Okada, Masashi; Matsushita, Yuji; Abe, Shigeru

    2012-04-01

    Oral candidiasis is often accompanied by severe inflammation, resulting in a decline in the quality of life of immunosuppressed individuals and elderly people. To develop a new oral therapeutic option for candidiasis, a nonpathogenic commensal oral probiotic microorganism, Streptococcus salivarius K12, was evaluated for its ability to modulate Candida albicans growth in vitro, and its therapeutic activity in an experimental oral candidiasis model was tested. In vitro inhibition of mycelial growth of C. albicans was determined by plate assay and fluorescence microscopy. Addition of S. salivarius K12 to modified RPMI 1640 culture medium inhibited the adherence of C. albicans to the plastic petri dish in a dose-dependent manner. Preculture of S. salivarius K12 potentiated its inhibitory activity for adherence of C. albicans. Interestingly, S. salivarius K12 was not directly fungicidal but appeared to inhibit Candida adhesion to the substratum by preferentially binding to hyphae rather than yeast. To determine the potentially anti-infective attributes of S. salivarius K12 in oral candidiasis, the probiotic was administered to mice with orally induced candidiasis. Oral treatment with S. salivarius K12 significantly protected the mice from severe candidiasis. These findings suggest that S. salivarius K12 may inhibit the process of invasion of C. albicans into mucous surfaces or its adhesion to denture acrylic resins by mechanisms not associated with the antimicrobial activity of the bacteriocin. S. salivarius K12 may be useful as a probiotic as a protective tool for oral care, especially with regard to candidiasis. PMID:22267663

  4. Effect of Streptococcus salivarius K12 on the In Vitro Growth of Candida albicans and Its Protective Effect in an Oral Candidiasis Model

    PubMed Central

    Hayama, Kazumi; Burton, Jeremy P.; Reid, Gregor; Okada, Masashi; Matsushita, Yuji; Abe, Shigeru

    2012-01-01

    Oral candidiasis is often accompanied by severe inflammation, resulting in a decline in the quality of life of immunosuppressed individuals and elderly people. To develop a new oral therapeutic option for candidiasis, a nonpathogenic commensal oral probiotic microorganism, Streptococcus salivarius K12, was evaluated for its ability to modulate Candida albicans growth in vitro, and its therapeutic activity in an experimental oral candidiasis model was tested. In vitro inhibition of mycelial growth of C. albicans was determined by plate assay and fluorescence microscopy. Addition of S. salivarius K12 to modified RPMI 1640 culture medium inhibited the adherence of C. albicans to the plastic petri dish in a dose-dependent manner. Preculture of S. salivarius K12 potentiated its inhibitory activity for adherence of C. albicans. Interestingly, S. salivarius K12 was not directly fungicidal but appeared to inhibit Candida adhesion to the substratum by preferentially binding to hyphae rather than yeast. To determine the potentially anti-infective attributes of S. salivarius K12 in oral candidiasis, the probiotic was administered to mice with orally induced candidiasis. Oral treatment with S. salivarius K12 significantly protected the mice from severe candidiasis. These findings suggest that S. salivarius K12 may inhibit the process of invasion of C. albicans into mucous surfaces or its adhesion to denture acrylic resins by mechanisms not associated with the antimicrobial activity of the bacteriocin. S. salivarius K12 may be useful as a probiotic as a protective tool for oral care, especially with regard to candidiasis. PMID:22267663

  5. In vitro and ex vivo assays of virulence in Candida albicans.

    PubMed

    Calderone, Richard A

    2009-01-01

    The measurement of virulence using ex vivo and in vitro models is discussed in the context of the human pathogenic yeast, Candida albicans. The models described are of two types. First, reconstituted tissues of various sorts are used that are derived from human carcinomas. The tissues are grown in vitro in complex media, attain a three-dimensional tissue structure, and retain cell-surface antigens typical of the specific tissue. Both adherence and invasion of tissues can be studied following infection with strains of C. albicans (1, 2). Further, one can increase the level of complexity by providing infected tissues with host phagocytes or cytokines such that an immune contribution to protection can be followed (3-5). The second model employs Drosophila melanogaster larvae that are infected with C. albicans (6). In this model, the progression of virulence is followed after injection of strains of a pathogen of interest into the fly abdomen. Thus, in the case of human pathogenic fungi, the recognition of host tissues and invasion by the specific pathogen can be studied in vitro and correlations developed for human disease. The obvious advantage to using animal models (e.g., mice) is reduced cost, such that large numbers of C. albicans strains can be assessed for their virulence properties. Additionally, another application of these models is in drug discovery. It is clear that there are both advantages and disadvantages of the use of alternate models other than a murine model, to evaluate disease, and this is discussed below. PMID:19152042

  6. IN VITRO INHIBITION OF YEAST GROWTH BY MOUSE ASCITES FLUID AND SERUM

    PubMed Central

    Summers, Donald F.; Hasenclever, H. F.

    1964-01-01

    Summers, Donald F. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.), and H. F. Hasenclever. In vitro inhibition of yeast growth by mouse ascites fluid and serum. J. Bacteriol. 87:1–7. 1964.—A nondialyzable heat-stable factor(s) present in experimentally produced mouse ascites fluid and in serum from these ascitic mice was shown to inhibit the invitro growth of several yeasts. The inhibitory activity was almost totally abolished by trypsin treatment of the ascites fluid, and was progressively diminished by repeated adsorption of the ascites fluid by heat-killed Candida albicans cells. A close relationship was shown to exist between growth inhibition by ascites fluid and concentration of free iron or nutrients in the growth medium. Increased concentration of nutrients or free iron caused diminution of inhibitory activity. PMID:14102855

  7. IN VITRO INHIBITION OF YEAST GROWTH BY MOUSE ASCITES FLUID AND SERUM.

    PubMed

    SUMMERS, D F; HASENCLEVER, H F

    1964-01-01

    Summers, Donald F. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.), and H. F. Hasenclever. In vitro inhibition of yeast growth by mouse ascites fluid and serum. J. Bacteriol. 87:1-7. 1964.-A nondialyzable heat-stable factor(s) present in experimentally produced mouse ascites fluid and in serum from these ascitic mice was shown to inhibit the invitro growth of several yeasts. The inhibitory activity was almost totally abolished by trypsin treatment of the ascites fluid, and was progressively diminished by repeated adsorption of the ascites fluid by heat-killed Candida albicans cells. A close relationship was shown to exist between growth inhibition by ascites fluid and concentration of free iron or nutrients in the growth medium. Increased concentration of nutrients or free iron caused diminution of inhibitory activity. PMID:14102855

  8. Effects of Treated versus Untreated Polystyrene on Caspofungin In Vitro Activity against Candida Species.

    PubMed

    Fothergill, Annette W; McCarthy, Dora I; Albataineh, Mohammad T; Sanders, Carmita; McElmeel, Maria; Wiederhold, Nathan P

    2016-03-01

    Significant interlaboratory variability is observed in testing the caspofungin susceptibility of Candida species by both the CLSI and EUCAST broth microdilution methodologies. We evaluated the influence of treated versus untreated polystyrene microtiter trays on caspofungin MICs using 209 isolates of four Candida species, including 16 C. albicans and 11 C. glabrata isolates with defined FKS mutations. Caspofungin MICs were also determined using the commercially available YeastOne and Etest assays and 102 isolates. All C. glabrata isolates had caspofungin MICs of ≥0.5 μg/ml, the clinical breakpoint for caspofungin resistance in this species, measured using trays made of treated polystyrene, regardless of the FKS status. In contrast, susceptible isolates could readily be distinguished from resistant/non-wild-type isolates when caspofungin MICs were measured using untreated polystyrene trays and both the YeastOne and Etest assays. Similar results were also observed for C. krusei isolates, as all isolates had caspofungin MICs above the threshold for resistance measured using treated polystyrene trays. In contrast, C. albicans isolates could be correctly identified as susceptible or resistant when caspofungin MICs were measured with treated or untreated trays and with the YeastOne and Etest assays. MICs falsely elevated above the resistance breakpoint were also not observed for C. tropicalis isolates. These results demonstrated that the use of treated polystyrene may be one factor that leads to falsely elevated caspofungin in vitro susceptibility results and that this may also be a greater issue for some Candida species than for others. PMID:26763959

  9. In Vitro Susceptibility and Trailing Growth Effect of Clinical Isolates of Candida Species to Azole Drugs

    PubMed Central

    Zomorodian, Kamiar; Bandegani, Azadeh; Mirhendi, Hossein; Pakshir, Keyvan; Alinejhad, Navvab; Poostforoush Fard, Ali

    2016-01-01

    Background: Emergence of resistance to respective antifungal drugs is a primary concern for the treatment of candidiasis. Hence, determining antifungal susceptibility of the isolated yeasts is of special importance for effective therapy. For this purpose, the clinical laboratory standard institute (CLSI) has introduced a broth microdilution method to determine minimum inhibitory concentration (MIC). However, the so-called “Trailing effect” phenomenon might sometimes pose ambiguity in the interpretation of the results. Objectives: The present study aimed to determine the in vitro susceptibility of clinical isolates of Candida against azoles and the frequency of the Trailing effect. Materials and Methods: A total of 193 Candida isolates were prospectively collected and identified through the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Using a broth microdilution test, according to the guidelines of CLSI M27-A3, antifungal susceptibilities of the isolated yeasts against Fluconazole (FLU), Itraconazole (ITR), Ketoconazole (KET) and Voriconazole (VOR) were assessed. Moreover, trailing growth was determined when a susceptible MIC was incubated for 24 hours, and turned into a resistant one after 48 hours of incubation. Results: Among the tested antifungal drugs in this study, the highest rate of resistance was observed against ITR (28.5%) followed by VOR (26.4%), FLU (20.8%) and KET (1.5%). The trailing effect was induced in 27 isolates (14.0%) by VOR, in 26 isolates (13.5%) by ITR, in 24 isolates (12.4%) by FLU, and in 19 isolates (9.8%) by KET. Conclusions: The monitoring of antifungal susceptibilities of Candida species isolated from clinical sources is highly recommended for the efficient management of patients. Moreover, the trailing effect should be taken into consideration once the interpretation of the results is intended. PMID:27127587

  10. Glycerol inhibition of ruminal lipolysis in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Supplemental glycerol inhibits rumen lipolysis, a prerequisite for rumen biohydrogenation, which is responsible for the saturation of dietary fatty acids consumed by ruminant animals. Feeding excess glycerol, however, adversely affects dry matter digestibility. To more clearly define the effect of...

  11. Chemical characterization by GC-MS and in vitro activity against Candida albicans of volatile fractions prepared from Artemisia dracunculus, Artemisia abrotanum, Artemisia absinthium and Artemisia vulgaris

    PubMed Central

    2014-01-01

    Background A large number of essential oils is reported to have significant activity against Candida albicans. But the different chemical composition influences the degree of their activity. The intention of this study was to investigate the chemical composition and the activity against Candida albicans of volatile oils obtained from Artemisia dracunculus, A. abrotanum, A. absinthium and A. vulgaris (Asteraceae). The aim of the study was to identify new chemical compounds that have effect against C. albicans. The essential oils were obtained by hydrodistillation or extraction with dichloromethane (a new procedure we developed trying to obtain better, more separated compounds) from air dried above ground plant material and analyzed by GC-MS. Additionally commercial essential oils from the same species were tested. The Candida albicans inhibition studies were carried out by the paper disc diffusion method. Results The essential oils shared common components but presented differences in composition and showed variable antifungal activity. Davanone and derivatives thereof, compounds with silphiperfolane skeleton, estragole, davanone oil, β-thujone, sabinyl acetate, herniarin, cis-chrysanthenyl acetate, 1,8-cineol, and terpineol were the main components of Artemisia volatiles. Conclusions Among the volatile fractions tested those from A. abrotanum containing davanone or silphiperfolane derivatives showed the highest antifungal activity. The in vitro tests revealed that the Artemisia oils are promising candidates for further research to develop novel anti-candida drugs. PMID:24475951

  12. In Vitro Antifungal Activities of Isavuconazole (BAL4815), Voriconazole, and Fluconazole against 1,007 Isolates of Zygomycete, Candida, Aspergillus, Fusarium, and Scedosporium Species▿

    PubMed Central

    Guinea, Jesús; Peláez, Teresa; Recio, Sandra; Torres-Narbona, Marta; Bouza, Emilio

    2008-01-01

    Isavuconazole (BAL4815) is a promising novel broad-spectrum triazole in late-stage clinical development that has proven active in vitro against Aspergillus and Candida species. We compared the in vitro activities of this agent with those of voriconazole and fluconazole by the CLSI (formerly NCCLS) M38-A and M27-A2 procedures against a large collection of 1,007 relevant opportunistic fungi collected from 1986 to 2007: Aspergillus spp. (n = 702), Candida spp. (n = 218), Zygomycetes (n = 45), Scedosporium spp. (n = 22), and Fusarium spp. (n = 20). All Candida isolates were from patients with candidemia. For isavuconazole, these techniques were also compared with the Etest. Isavuconazole and voriconazole had MICs at which 50% and 90% of isolates were inhibited (MIC50 and MIC90), respectively, of 1 and 1 μg/ml and 0.5 and 1 μg/ml against Aspergillus spp. and of 0.015 and 0.03 μg/ml and 0.25 and 0.125 μg/ml against Candida spp. (including fluconazole-resistant strains). The MIC50 partial and complete inhibition end points of isavuconazole and voriconazole against the non-Aspergillus molds were as follows: 1 and 2 μg/ml and 16 and >16 μg/ml against Zygomycetes; 1 and 4 μg/ml and 0.25 and 0.5 μg/ml against Scedosporium apiospermum; 4 to 16 and >16 μg/ml and 4 to 8 and 16 to >16 μg/ml (ranges) against Scedosporium prolificans; and 16 and 16 μg/ml and 4 and 4 μg/ml against Fusarium spp. Isavuconazole showed minimal fungicidal concentrations for 50% and 90% of the isolates of 1 and 1 μg/ml against Aspergillus, 16 and >16 μg/ml against Candida, and 4 and >16 μg/ml against Zygomycetes, respectively, and >16 μg/ml against the remaining molds. The Etest proved to be a suitable alternative method for determining the antifungal activities of isavuconazole against Aspergillus and Candida; the Etest results showed 96% and 93% agreement with the results of the CLSI M38-A and M27-A2 methods, respectively. PMID:18212101

  13. Glycerol inhibition of ruminal lipolysis in vitro.

    PubMed

    Edwards, H D; Anderson, R C; Miller, R K; Taylor, T M; Hardin, M D; Smith, S B; Krueger, N A; Nisbet, D J

    2012-09-01

    Supplemental glycerol inhibits rumen lipolysis, a prerequisite for rumen biohydrogenation, which is responsible for the saturation of dietary fatty acids consumed by ruminant animals. Feeding excess glycerol, however, adversely affects dry matter digestibility. To more clearly define the effect of supplemental glycerol on rumen lipolysis, mixed populations of ruminal bacteria were incubated with 6 or 20% glycerol (vol/vol). After 48-h anaerobic incubation of mixed culture rumen fluid, rates of free fatty acid production (nmol/mL per h) for the 6 and 20% glycerol-supplemented samples were decreased by 80 and 86%, respectively, compared with rates from nonsupplemented control cultures (12.4±1.0; mean ± SE). Conversely, assay of the prominent ruminal lipase-producing bacteria Anaerovibrio lipolyticus 5S, Butyrivibrio fibrisolvens 49, and Propionibacterium species avidum and acnes revealed no effect of 2 or 10% (vol/vol) added glycerol on lipolytic activity by these organisms. Supplementing glycerol at 6% on a vol/vol basis, equivalent to supplementing glycerol at approximately 8 to 15% of diet dry matter, effectively reduced lipolysis. However, the mechanism of glycerol inhibition of ruminal lipolysis remains to be demonstrated. PMID:22916923

  14. Effects of Candida norvegensis Live Cells on In vitro Oat Straw Rumen Fermentation

    PubMed Central

    Ruiz, Oscar; Castillo, Yamicela; Arzola, Claudio; Burrola, Eduviges; Salinas, Jaime; Corral, Agustín; Hume, Michael E.; Murillo, Manuel; Itza, Mateo

    2016-01-01

    This study evaluated the effect of Candida norvegensis (C. norvegensis) viable yeast culture on in vitro ruminal fermentation of oat straw. Ruminal fluid was mixed with buffer solution (1:2) and anaerobically incubated with or without yeast at 39°C for 0, 4, 8, 16, and 24 h. A fully randomized design was used. There was a decrease in lactic acid (quadratic, p = 0.01), pH, (quadratic, p = 0.02), and yeasts counts (linear, p<0.01) across fermentation times. However, in vitro dry matter disappearance (IVDMD) and ammonia-N increased across fermentation times (quadratic; p<0.01 and p<0.02, respectively). Addition of yeast cells caused a decrease in pH values compared over all fermentation times (p<0.01), and lactic acid decreased at 12 h (p = 0.05). Meanwhile, yeast counts increased (p = 0.01) at 12 h. C. norvegensis increased ammonia-N at 4, 8, 12, and 24 h (p<0.01), and IVDMD of oat straw increased at 8, 12, and 24 h (p<0.01) of fermentation. Yeast cells increased acetate (p<0.01), propionate (p<0.03), and butyrate (p<0.03) at 8 h, while valeriate and isovaleriate increased at 8, 12, and 24 h (p<0.01). The yeast did not affect cellulolytic bacteria (p = 0.05), but cellulolytic fungi increased at 4 and 8 h (p<0.01), whereas production of methane decreased (p<0.01) at 8 h. It is concluded that addition of C. norvegensis to in vitro oat straw fermentation increased ruminal fermentation parameters as well as microbial growth with reduction of methane production. Additionally, yeast inoculum also improved IVDMD. PMID:26732446

  15. Effects of Candida norvegensis Live Cells on In vitro Oat Straw Rumen Fermentation.

    PubMed

    Ruiz, Oscar; Castillo, Yamicela; Arzola, Claudio; Burrola, Eduviges; Salinas, Jaime; Corral, Agustín; Hume, Michael E; Murillo, Manuel; Itza, Mateo

    2016-02-01

    This study evaluated the effect of Candida norvegensis (C. norvegensis) viable yeast culture on in vitro ruminal fermentation of oat straw. Ruminal fluid was mixed with buffer solution (1:2) and anaerobically incubated with or without yeast at 39°C for 0, 4, 8, 16, and 24 h. A fully randomized design was used. There was a decrease in lactic acid (quadratic, p = 0.01), pH, (quadratic, p = 0.02), and yeasts counts (linear, p<0.01) across fermentation times. However, in vitro dry matter disappearance (IVDMD) and ammonia-N increased across fermentation times (quadratic; p<0.01 and p<0.02, respectively). Addition of yeast cells caused a decrease in pH values compared over all fermentation times (p<0.01), and lactic acid decreased at 12 h (p = 0.05). Meanwhile, yeast counts increased (p = 0.01) at 12 h. C. norvegensis increased ammonia-N at 4, 8, 12, and 24 h (p<0.01), and IVDMD of oat straw increased at 8, 12, and 24 h (p<0.01) of fermentation. Yeast cells increased acetate (p<0.01), propionate (p<0.03), and butyrate (p<0.03) at 8 h, while valeriate and isovaleriate increased at 8, 12, and 24 h (p<0.01). The yeast did not affect cellulolytic bacteria (p = 0.05), but cellulolytic fungi increased at 4 and 8 h (p<0.01), whereas production of methane decreased (p<0.01) at 8 h. It is concluded that addition of C. norvegensis to in vitro oat straw fermentation increased ruminal fermentation parameters as well as microbial growth with reduction of methane production. Additionally, yeast inoculum also improved IVDMD. PMID:26732446

  16. In vitro sensitivity of Candida spp. to hematoporphyrin monomethyl ether-mediated photodynamic inactivation

    NASA Astrophysics Data System (ADS)

    Wang, Yucheng; Wang, Ying; Wu, Sumin; Gu, Ying

    2014-11-01

    Background: An increasing prevalence of Candida infections has emerged with the wide use of immune-suppressants and antibiotics. Current antifungal drugs exhibit low efficiency and high toxicity to the normal organs. Photodynamic inactivation (PDI) provides an alternative therapeutic strategy involving the use of photosensitizer (PS) and light irradiation. This study evaluated PDI effects against strains of C. albicans, C. parapsilosis, C. krusei and C. glabrata, using the PS of hematoporphyrin monomethyl ether (HMME), which is a second-generation PS clinically approved in China. Methods: Suspensions (~106 CFU/ml) were incubated with seven HMME concentrations (0.25~50 μM) for 30 min followed by 532-nm laser irradiation for 10 min at 40 mW/cm2. Viability of cells was assayed by CFU counting. Furthermore, fetal calf serum (10%) and singlet oxygen quencher sodium azide (100mM) were respectively added to the suspension of C. krusei to evaluate their roles in PDI process. Results: Among the four species, C. albicans was the most sensitive to PDI; 4 log10 killing was achieved at the concentration of 7.5 μM. C. glabrata was the most resistant; 3 log10 killing was not obtained even at PS concentration of 50 μM. PDI effects against C. krusei were inhibited by both serum and sodium azide. Conclusions: HMME-mediated PDI was able to effectively kill Candida in our experimental conditions, mainly through a Type Ⅱ photoprocess. However, the effects could be intensively reversed by the presence of serum. Thus, there might be a long way before HMME can be used in fighting against Candida in real infectious foci.

  17. In Vitro Fungicidal Activities of Anidulafungin, Caspofungin, and Micafungin against Candida glabrata, Candida bracarensis, and Candida nivariensis Evaluated by Time-Kill Studies

    PubMed Central

    Gil-Alonso, Sandra; Jauregizar, Nerea; Cantón, Emilia; Eraso, Elena

    2015-01-01

    Anidulafungin, caspofungin, and micafungin killing activities against Candida glabrata, Candida bracarensis, and Candida nivariensis were evaluated by the time-kill methodology. The concentrations assayed were 0.06, 0.125, and 0.5 μg/ml, which are achieved in serum. Anidulafungin and micafungin required between 13 and 26 h to reach the fungicidal endpoint (99.9% killing) against C. glabrata and C. bracarensis. All echinocandins were less active against C. nivariensis. PMID:25801575

  18. Evaluation of the in vitro antimicrobial properties of ultraviolet A/riboflavin mediated crosslinking on Candida albicans and Fusarium solani

    PubMed Central

    Sun, Bing; Li, Zhi-Wei; Yu, Hai-Qun; Tao, Xiang-Chen; Zhang, Yong; Mu, Guo-Ying

    2014-01-01

    AIM To evaluate the antimicrobial properties of ultraviolet A (UVA) (365 nm)/riboflavin against Candida albicans and Fusarium solani. METHODS Two fungus isolates were cultured in vitro and prepared with 10-fold serial PBS dilutions of cell concentration. For each dilution of fungus suspension, the concentration (colony-forming units/mL, CFU/mL) and the inactivation ratio of fungal cells were evaluated under 4 conditions: no treatment (control), UVA (365 nm)/riboflavin, riboflavin, and UVA (365 nm). RESULTS The cell concentration decreased in UVA (365 nm)/riboflavin group for Candida albicans at each dilution and Fusarium solani at dilutions of 104, 103, 102 CFU/mL, when compared with that in control, riboflavin, and UVA (365 nm) groups (P<0.01). No difference of cell concentration was detected amongst the culture of control, riboflavin, and UVA (365 nm) groups for the two fungus. There is a negative correlation between suspension concentration (log-transformed) and the inactivation ratio in UVA (365 nm)/riboflavin group for Candida albicans and Fusarium solani (P<0.01). CONCLUSION According to the standard protocol of corneal collagen cross-linking, UVA (365 nm)/riboflavin combination treatment is found to moderately inactivate the viability of Candida albicans and Fusarium solani in vitro. The inactivation ratio was found to increase with the decrease of cell concentration under UVA (365 nm)/riboflavin condition. PMID:24790859

  19. In Vitro Activities of Six Antifungal Drugs Against Candida glabrata Isolates: An Emerging Pathogen

    PubMed Central

    Amirrajab, Nasrin; Badali, Hamid; Didehdar, Mojtaba; Afsarian, Mohammad Hosein; Mohammadi, Rasoul; Lotfi, Nazanin; Shokohi, Tahereh

    2016-01-01

    Background Candida glabrata is a pathogenic yeast with several unique biological features and associated with an increased incidence rate of candidiasis. It exhibits a great degree of variation in its pathogenicity and antifungal susceptibility. Objectives The aim of the present study was to evaluate the in vitro antifungal susceptibilities of the following six antifungal drugs against clinical C. glabrata strains: amphotericin B (AmB), ketoconazole (KTZ), fluconazole (FCZ), itraconazole (ITZ), voriconazole (VCZ), and caspofungin (CASP). Materials and Methods Forty clinical C. glabrata strains were investigated using DNA sequencing. The in vitro antifungal susceptibility was determined as described in clinical laboratory standard institute (CLSI) documents (M27-A3 and M27-S4). Results The sequence analysis of the isolate confirmed as C. glabrata and deposited on NCBI GenBank under the accession number no. KT763084-KT763123. The geometric mean MICs against all the tested strains were as follows, in increasing order: CASP (0.17 g/mL), VCZ (0.67 g/mL), AmB (1.1 g/mL), ITZ (1.82 g/mL), KTZ (1.85 g/mL), and FCZ (6.7 g/mL). The resistance rates of the isolates to CASP, FCZ, ITZ, VZ, KTZ, and AmB were 5%, 10%, 72.5%, 37.5%, 47.5%, and 27.5%, respectively. Conclusions These findings confirm that CASP, compared to the other antifungals, is the potent agent for treating candidiasis caused by C. glabrata. However, the clinical efficacy of these novel antifungals remains to be determined. PMID:27540459

  20. Geranylgeranylacetone inhibits ovarian cancer progression in vitro and in vivo

    SciTech Connect

    Hashimoto, Kae; Morishige, Ken-ichirou . E-mail: mken@gyne.med.osaka-u.ac.jp; Sawada, Kenjiro; Ogata, Seiji; Tahara, Masahiro; Shimizu, Shoko; Sakata, Masahiro; Tasaka, Keiichi; Kimura, Tadashi

    2007-04-27

    Geranylgeranylacetone (GGA), an isoprenoid compound, is an anti-ulcer drug developed in Japan. In our previous study, GGA was shown to inhibit ovarian cancer invasion by attenuating Rho activation [K. Hashimoto, K. Morishige, K. Sawada, M. Tahara, S. Shimizu, M. Sakata, K. Tasaka, Y. Murata, Geranylgeranylacetone inhibits lysophosphatidic acid-induced invasion of human ovarian carcinoma cells in vitro. Cancer 103 (2005) 1529-1536.]. In the present study, GGA treatment inhibited ovarian cancer progression in vitro and suppressed the tumor growth and ascites in the in vivo ovarian cancer model. In vitro analysis, treatment of cancer cells by GGA resulted in the inhibition of cancer cell proliferation, the inactivation of Ras, and the suppression of tyrosine phosphorylation of mitogen-activated protein kinase (MAPK). In conclusion, this is the first report that GGA inhibited ovarian cancer progression and the anti-tumor effect by GGA is, at least in part, derived not only from the suppression of Rho activation but also Ras-MAPK activation.

  1. Suppression of polymorphonuclear (PMN) and monocyte-mediated inhibition of Candida albicans growth by delta-9-tetrahydrocannabinol

    SciTech Connect

    Djeu, J.Y.; Parapanios, A.; Halkias, D.; Friedman, H.

    1986-03-05

    This study was an in vitro attempt to identify the effector cells responsible for growth inhibition of the opportunistic fungus, candida albicans, and to determine if THC or another marijuana derivatives, 11-hydroxyTHC, would adversely affect their function. Using a 24h radiolabel assay, the authors found that growth inhibition of C. albicans was primarily mediated by PMN and monocytes that could be isolated normal human peripheral blood. Both effector cell types caused almost complete inhibition of Candida growth at effector/target ratio of 300/1 and inhibition was often still seen at 30/1-. Incubation of PMN, PBL, or monocytes for 1 hr at 37C with THC or 11-hydroxyTHC caused a marked suppression of function in all 3 cell populations. Maximal suppression was obtained with 7.5-10..mu..g/ml of the drugs in medium containing 10% fetal bovine serum (FBS) or with 2-4..mu..g/ml in 1% FBS. These drug concentrations did not affect lymphoid cell viability or candida growth in the absence of lymphoid effector cells. Marijuana derivatives, therefore, are doubly dangerous in that opportunistic fungi such as C. albicans can grow in their presence while the effector cells that control fungal growth are readily inactivated.

  2. In vitro modulation of probiotic bacteria on the biofilm of Candida glabrata.

    PubMed

    Chew, Shu Yih; Cheah, Yoke Kqueen; Seow, Heng Fong; Sandai, Doblin; Than, Leslie Thian Lung

    2015-08-01

    A conspicuous new concept of pathogens living as the microbial societies in the human host rather than free planktonic cells has raised considerable concerns among scientists and clinicians. Fungal biofilms are communities of cells that possess distinct characteristic such as increased resistance to the immune defence and antimycotic agents in comparison to their planktonic cells counterpart. Therefore, inhibition of the biofilm may represent a new paradigm for antifungal development. In this study, we aim to evaluate the in vitro modulation of vulvovaginal candidiasis (VVC)-causing Candida glabrata biofilms using probiotic lactobacilli strains. Probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 were shown to have completely inhibited C. glabrata biofilms and the results were corroborated by scanning electron microscopy (SEM), which revealed scanty structures of the mixed biofilms of C. glabrata and probiotic lactobacilli strains. In addition, biofilm-related C. glabrata genes EPA6 and YAK1 were downregulated in response to the probiotic lactobacilli challenges. The present study suggested that probiotic L. rhamnosus GR-1 and L. reuteri RC-14 strains inhibited C. glabrata biofilm by partially impeding the adherence of yeast cells and the effect might be contributed by the secretory compounds produced by these probiotic lactobacilli strains. Further investigations are required to examine and identify the biofilm inhibitory compounds and the mechanism of probiotic actions of these lactobacilli strains. PMID:26028405

  3. Olive leaf extract activity against Candida albicans and C. dubliniensis - the in vitro viability study.

    PubMed

    Zorić, Nataša; Kopjar, Nevenka; Kraljić, Klara; Oršolić, Nada; Tomić, Siniša; Kosalec, Ivan

    2016-09-01

    Olive leaf extract is characterized by a high content of polyphenols (oleuropein, hydroxytyrosol and their derivatives), which is associated with its therapeutic properties. The objective of the present research was to evaluate the antifungal activity of olive leaf extract against Candida albicans ATCC 10231 and C. dubliniensis CBS 7987 strains. Minimum inhibitory concentrations (MIC) of the extract were determined by several in vitro assays. The extract showed a concentration depended effect on the viability of C. albicans with MIC value of 46.875 mg mL-1 and C. dubliniensis with MIC value 62.5 mg mL-1. Most sensitive methods for testing the antifungal effect of the extracts were the trypan blue exclusion method and fluorescent dye exclusion method while MIC could not be determined by the method according to the EUCAST recommendation suggesting that herbal preparations contain compounds that may interfere with this susceptibility testing. The fluorescent dye exclusion method was also used for the assessment of morphological changes in the nuclei of treated cells. According to the obtained results, olive leaf extract is less effective against the tested strains than hydroxytyrosol, an olive plant constituent tested in our previous study. PMID:27383889

  4. In Vitro Antifungal Susceptibility Profiles of Candida albicans Complex Isolated from Patients with Respiratory Infections.

    PubMed

    Sharifynia, Somayeh; Badali, Hamid; Sharifi Sorkherizi, Mina; Shidfar, Mohammad Reza; Hadian, Atefe; Shahrokhi, Shadi; Ghandchi, Ghazale; Rezaie, Sassan

    2016-06-01

    Candidiasis, the main opportunistic fungal infection has been increased over the past decades. This study aimed to characterize C.albicans species complex (C.albicans, C.dubliniensis, and C.africana) isolated from patients with respiratory infections by molecular tools and in vitro antifungal susceptibilities by using broth microdilution method according to CLSI M27-A3 guidelines. Totally, 121 respiratory samples were collected from patients with respiratory infections. Of these, 83 strains were germ tube positive and green colonies on chromogenic media, so initially identified as C.albicans species complex and subsequently were classified as C.albicans (89.15%), C.dubliniensis (9.63%), and C.africana (1.2%) based on PCR-RFLP and amplification of hwp1 gene. Minimum inhibitory concentration (MICs) results showed that all tested isolates of C.albicans complex were highly susceptible to triazole drugs. However, caspofungin had highest activity against C.albicans, C.dubliniensis, and C.africana. Our findings indicated the variety of antifungal resistance of Candida strains in different areas. These results may increase the knowledge about the local distribution of the mentioned strains as well as their antifungal susceptibility pattern which play an important role in appropriate therapy. PMID:27306344

  5. The novel arylamidine T-2307 maintains in vitro and in vivo activity against echinocandin-resistant Candida albicans.

    PubMed

    Wiederhold, Nathan P; Najvar, Laura K; Fothergill, Annette W; Bocanegra, Rosie; Olivo, Marcos; McCarthy, Dora I; Kirkpatrick, William R; Fukuda, Yoshiko; Mitsuyama, Junichi; Patterson, Thomas F

    2015-02-01

    We evaluated the in vitro and in vivo activities of the investigational arylamidine T-2307 against echinocandin-resistant Candida albicans. T-2307 demonstrated potent in vitro activity, and daily subcutaneous doses between 0.75 and 6 mg/kg of body weight significantly improved survival and reduced fungal burden compared to placebo control and caspofungin (10 mg/kg/day) in mice with invasive candidiasis caused by an echinocandin-resistant strain. Thus, T-2307 may have potential use in the treatment of echinocandin-resistant C. albicans infections. PMID:25451054

  6. Gymnemic acids inhibit hyphal growth and virulence in Candida albicans.

    PubMed

    Vediyappan, Govindsamy; Dumontet, Vincent; Pelissier, Franck; d'Enfert, Christophe

    2013-01-01

    Candida albicans is an opportunistic and polymorphic fungal pathogen that causes mucosal, disseminated and invasive infections in humans. Transition from the yeast form to the hyphal form is one of the key virulence factors in C. albicans contributing to macrophage evasion, tissue invasion and biofilm formation. Nontoxic small molecules that inhibit C. albicans yeast-to-hypha conversion and hyphal growth could represent a valuable source for understanding pathogenic fungal morphogenesis, identifying drug targets and serving as templates for the development of novel antifungal agents. Here, we have identified the triterpenoid saponin family of gymnemic acids (GAs) as inhibitor of C. albicans morphogenesis. GAs were isolated and purified from Gymnema sylvestre leaves, the Ayurvedic traditional medicinal plant used to treat diabetes. Purified GAs had no effect on the growth and viability of C. albicans yeast cells but inhibited its yeast-to-hypha conversion under several hypha-inducing conditions, including the presence of serum. Moreover, GAs promoted the conversion of C. albicans hyphae into yeast cells under hypha inducing conditions. They also inhibited conidial germination and hyphal growth of Aspergillus sp. Finally, GAs inhibited the formation of invasive hyphae from C. albicans-infected Caenorhabditis elegans worms and rescued them from killing by C. albicans. Hence, GAs could be useful for various antifungal applications due to their traditional use in herbal medicine. PMID:24040201

  7. In vitro effects of Salvia officinalis L. essential oil on Candida albicans

    PubMed Central

    Sookto, Tularat; Srithavaj, Theerathavaj; Thaweboon, Sroisiri; Thaweboon, Boonyanit; Shrestha, Binit

    2013-01-01

    Objective To determine the anticandidal activities of Salvia officinalis L. (S. officinalis) essential oil against Candida albicans (C. albicans) and the inhibitory effects on the adhesion of C. albicans to polymethyl methacrylate (PMMA) resin surface. Methods Disc diffusion method was first used to test the anticandidal activities of the S. officinalis L. essential oil against the reference strain (ATCC 90028) and 2 clinical strains of C. albicans. Then the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were determined by modified membrane method. The adhesion of C. albicans to PMMA resin surface was assessed after immersion with S. officinalis L. essential oil at various concentrations of 1×MIC, 0.5×MIC and 0.25×MIC at room temperature for 30 min. One-way ANOVA was used to compare the Candida cell adhesion with the pretreatment agents and Tukey's test was used for multiple comparisons. Results S. officinalis L. essential oil exhibited anticandidal activity against all strains of C. albicans with inhibition zone ranging from 40.5 mm to 19.5 mm. The MIC and MLC of the oil were determined as 2.780 g/L against all test strains. According to the effects on C. albicans adhesion to PMMA resin surface, it was found that immersion in the essential oil at concentrations of 1×MIC (2.780 g/L), 0.5×MIC (1.390 g/L) and 0.25×MIC (0.695 g/L) for 30 min significantly reduced the adhesion of all 3 test strains to PMMA resin surface in a dose dependent manner (P<0.05). Conclusions S. officinalis L. essential oil exhibited anticandidal activities against C. albicans and had inhibitory effects on the adhesion of the cells to PMMA resin surface. With further testing and development, S. officinalis essential oil may be used as an antifungal denture cleanser to prevent candidal adhesion and thus reduce the risk of candida-associated denture stomatitis. PMID:23646301

  8. In vitro antimicrobial properties of coconut oil on Candida species in Ibadan, Nigeria.

    PubMed

    Ogbolu, D O; Oni, A A; Daini, O A; Oloko, A P

    2007-06-01

    The emergence of antimicrobial resistance, coupled with the availability of fewer antifungal agents with fungicidal actions, prompted this present study to characterize Candida species in our environment and determine the effectiveness of virgin coconut oil as an antifungal agent on these species. In 2004, 52 recent isolates of Candida species were obtained from clinical specimens sent to the Medical Microbiology Laboratory, University College Hospital, Ibadan, Nigeria. Their susceptibilities to virgin coconut oil and fluconazole were studied by using the agar-well diffusion technique. Candida albicans was the most common isolate from clinical specimens (17); others were Candida glabrata (nine), Candida tropicalis (seven), Candida parapsilosis (seven), Candida stellatoidea (six), and Candida krusei (six). C. albicans had the highest susceptibility to coconut oil (100%), with a minimum inhibitory concentration (MIC) of 25% (1:4 dilution), while fluconazole had 100% susceptibility at an MIC of 64 microg/mL (1:2 dilution). C. krusei showed the highest resistance to coconut oil with an MIC of 100% (undiluted), while fluconazole had an MIC of > 128 microg/mL. It is noteworthy that coconut oil was active against species of Candida at 100% concentration compared to fluconazole. Coconut oil should be used in the treatment of fungal infections in view of emerging drug-resistant Candida species. PMID:17651080

  9. Antimicrobial blue light inactivation of Candida albicans: In vitro and in vivo studies.

    PubMed

    Zhang, Yunsong; Zhu, Yingbo; Chen, Jia; Wang, Yucheng; Sherwood, Margaret E; Murray, Clinton K; Vrahas, Mark S; Hooper, David C; Hamblin, Michael R; Dai, Tianhong

    2016-07-01

    Fungal infections are a common cause of morbidity, mortality and cost in critical care populations. The increasing emergence of antimicrobial resistance necessitates the development of new therapeutic approaches for fungal infections. In the present study, we investigated the effectiveness of an innovative approach, antimicrobial blue light (aBL), for inactivation of Candida albicans in vitro and in infected mouse burns. A bioluminescent strain of C. albicans was used. The susceptibilities to aBL (415 nm) were compared between C. albicans and human keratinocytes. The potential development of aBL resistance by C. albicans was investigated via 10 serial passages of C. albicans on aBL exposure. For the animal study, a mouse model of thermal burn infected with the bioluminescent C. albicans strain was used. aBL was delivered to mouse burns approximately 12 h after fungal inoculation. Bioluminescence imaging was performed to monitor in real time the extent of infection in mice. The results obtained from the studies demonstrated that C. albicans was approximately 42-fold more susceptible to aBL than human keratinocytes. Serial passaging of C. albicans on aBL exposure implied a tendency of reduced aBL susceptibility of C. albicans with increasing numbers of passages; however, no statistically significant difference was observed in the post-aBL survival rate of C. albicans between the first and the last passage (P>0.05). A single exposure of 432 J/cm(2) aBL reduced the fungal burden in infected mouse burns by 1.75-log10 (P=0.015). Taken together, our findings suggest aBL is a potential therapeutic for C. albicans infections. PMID:26909654

  10. In vitro evaluation of antifungal activity of monolaurin against Candida albicans biofilms.

    PubMed

    Seleem, Dalia; Chen, Emily; Benso, Bruna; Pardi, Vanessa; Murata, Ramiro M

    2016-01-01

    Monolaurin (also known as glycerol monolaurate) is a natural compound found in coconut oil and is known for its protective biological activities as an antimicrobial agent. The nature of oral candidiasis and the increased antifungal resistance demand the search for novel antifungal therapeutic agents. In this study, we examine the antifungal activity of monolaurin against Candida albicans biofilms (strain ATCC:SC5314/MYA2876) in vitro and investigate whether monolaurin can alter gene expression of host inflammatory cytokines, IL-1α and IL-1β. In a co-culture model, oral fibroblast cells were cultured simultaneously with C. albicans for 24 hrs followed by the exposure to treatments of monolaurin (3.9-2,500 µM), positive control fluconazole (32.2 µM), and vehicle control group (1% ethanol), which was a model used to evaluate the cytotoxicity of monolaurin on fibroblasts as well as to analyze morphological characteristics of biofilms through fluorescence microscopy. In addition, the co-culture model was used for RNA extraction of oral fibroblasts to assess gene expression of host inflammatory cytokines, using quantitative real-time PCR. Our results showed the MIC and MFC of monolaurin were in the range 62.5-125 µM and 125-250 µM, respectively. Biofilm antifungal assay showed significant reduction in Log (CFU/ml) of biofilms treated with 1,250 and 2,500 µM of 1-monolaurin when compared to the control groups . There was also a significant down-regulation of IL-1α and IL-1β in the co-culture treated with monolaurin. It can be concluded that monolaurin has a potential antifungal activity against C. albicans and can modulate the pro-inflammatory response of the host. PMID:27366648

  11. In Vitro and In Vivo Antifungal Activity of Lichochalcone-A against Candida albicans Biofilms

    PubMed Central

    Seleem, Dalia; Benso, Bruna; Noguti, Juliana; Pardi, Vanessa; Murata, Ramiro Mendonça

    2016-01-01

    Oral candidiasis (OC) is an opportunistic fungal infection with high prevalence among immunocompromised patients. Candida albicans is the most common fungal pathogen responsible for OC, often manifested in denture stomatitis and oral thrush. Virulence factors, such as biofilms formation and secretion of proteolytic enzymes, are key components in the pathogenicity of C. albicans. Given the limited number of available antifungal therapies and the increase in antifungal resistance, demand the search for new safe and effective antifungal treatments. Lichochalcone-A is a polyphenol natural compound, known for its broad protective activities, as an antimicrobial agent. In this study, we investigated the antifungal activity of lichochalcone-A against C. albicans biofilms both in vitro and in vivo. Lichochalcone-A (625 μM; equivalent to 10x MIC) significantly reduced C. albicans (MYA 2876) biofilm growth compared to the vehicle control group (1% ethanol), as indicated by the reduction in the colony formation unit (CFU)/ml/g of biofilm dry weight. Furthermore, proteolytic enzymatic activities of proteinases and phospholipases, secreted by C. albicans were significantly decreased in the lichochalcone-A treated biofilms. In vivo model utilized longitudinal imaging of OC fungal load using a bioluminescent-engineered C. albicans (SKCa23-ActgLUC) and coelenterazine substrate. Mice treated with lichochalcone-A topical treatments exhibited a significant reduction in total photon flux over 4 and 5 days post-infection. Similarly, ex vivo analysis of tongue samples, showed a significant decrease in CFU/ml/mg in tongue tissue sample of lichochalcone-A treated group, which suggest the potential of lichochalcone-A as a novel antifungal agent for future clinical use. PMID:27284694

  12. In Vitro and In Vivo Antifungal Activity of Lichochalcone-A against Candida albicans Biofilms.

    PubMed

    Seleem, Dalia; Benso, Bruna; Noguti, Juliana; Pardi, Vanessa; Murata, Ramiro Mendonça

    2016-01-01

    Oral candidiasis (OC) is an opportunistic fungal infection with high prevalence among immunocompromised patients. Candida albicans is the most common fungal pathogen responsible for OC, often manifested in denture stomatitis and oral thrush. Virulence factors, such as biofilms formation and secretion of proteolytic enzymes, are key components in the pathogenicity of C. albicans. Given the limited number of available antifungal therapies and the increase in antifungal resistance, demand the search for new safe and effective antifungal treatments. Lichochalcone-A is a polyphenol natural compound, known for its broad protective activities, as an antimicrobial agent. In this study, we investigated the antifungal activity of lichochalcone-A against C. albicans biofilms both in vitro and in vivo. Lichochalcone-A (625 μM; equivalent to 10x MIC) significantly reduced C. albicans (MYA 2876) biofilm growth compared to the vehicle control group (1% ethanol), as indicated by the reduction in the colony formation unit (CFU)/ml/g of biofilm dry weight. Furthermore, proteolytic enzymatic activities of proteinases and phospholipases, secreted by C. albicans were significantly decreased in the lichochalcone-A treated biofilms. In vivo model utilized longitudinal imaging of OC fungal load using a bioluminescent-engineered C. albicans (SKCa23-ActgLUC) and coelenterazine substrate. Mice treated with lichochalcone-A topical treatments exhibited a significant reduction in total photon flux over 4 and 5 days post-infection. Similarly, ex vivo analysis of tongue samples, showed a significant decrease in CFU/ml/mg in tongue tissue sample of lichochalcone-A treated group, which suggest the potential of lichochalcone-A as a novel antifungal agent for future clinical use. PMID:27284694

  13. In vitro evaluation of antifungal activity of monolaurin against Candida albicans biofilms

    PubMed Central

    Benso, Bruna; Pardi, Vanessa

    2016-01-01

    Monolaurin (also known as glycerol monolaurate) is a natural compound found in coconut oil and is known for its protective biological activities as an antimicrobial agent. The nature of oral candidiasis and the increased antifungal resistance demand the search for novel antifungal therapeutic agents. In this study, we examine the antifungal activity of monolaurin against Candida albicans biofilms (strain ATCC:SC5314/MYA2876) in vitro and investigate whether monolaurin can alter gene expression of host inflammatory cytokines, IL-1α and IL-1β. In a co-culture model, oral fibroblast cells were cultured simultaneously with C. albicans for 24 hrs followed by the exposure to treatments of monolaurin (3.9–2,500 µM), positive control fluconazole (32.2 µM), and vehicle control group (1% ethanol), which was a model used to evaluate the cytotoxicity of monolaurin on fibroblasts as well as to analyze morphological characteristics of biofilms through fluorescence microscopy. In addition, the co-culture model was used for RNA extraction of oral fibroblasts to assess gene expression of host inflammatory cytokines, using quantitative real-time PCR. Our results showed the MIC and MFC of monolaurin were in the range 62.5–125 µM and 125–250 µM, respectively. Biofilm antifungal assay showed significant reduction in Log (CFU/ml) of biofilms treated with 1,250 and 2,500 µM of 1-monolaurin when compared to the control groups . There was also a significant down-regulation of IL-1α and IL-1β in the co-culture treated with monolaurin. It can be concluded that monolaurin has a potential antifungal activity against C. albicans and can modulate the pro-inflammatory response of the host. PMID:27366648

  14. Real time optical coherence tomography monitoring of Candida albicans biofilm in vitro during photodynamic treatment

    NASA Astrophysics Data System (ADS)

    Suzuki, Luis Cláudio; Araujo Prates, Renato; Raele, Marcus Paulo; Zanardi di Freitas, Anderson; Simões Ribeiro, Martha

    2010-04-01

    The biofilm formed by Candida albicans is the mainly cause of infections associated to medical devices such as catheters. Studies have shown that photodynamic antimicrobial therapy (PAT) has lethal effect on C. albicans, and it is based on photosensitizer (PS) in the presence of low intensity light to generate reactive oxygen species in biological systems. The aim of this study was to analyze in real time, by Optical Coherence Tomography (OCT), the alterations in C. albicans biofilm in vitro during PAT using methylene blue (MB) as a PS and red light. An OCT system with working at 930nm was used, sequential images of 2000×512 pixels were generated at the frame rate of 2.5frames/sec. The dimension of the analyzed sample was 6000μm wide by 1170μm of depth corrected by refraction index of 1.35. We recorded 1min. before and after the irradiation with LED for PAT, generating 8min. of video. For biofilm formation, discs were made from elastomeric silicone catheters. The PS was dissolved in PBS solution, and a final concentration of 1mM MB was applied on biofilm, followed by a red LED irradiation (λ=630nm+/-20nm) during 6min. We performed a curve of survival fraction versus time of irradiation and it was reduced by 100% following 6min. of irradiation. OCT was performed for measurement of biofilm thickness of 110μm when biofilm was formed. During irradiation, the variation of biofilm thickness was ~70μm. We conclude that OCT system is able to show real time optical changes provided by PAT in yeasts organized in biofilm.

  15. Self-assembled amphotericin B-loaded polyglutamic acid nanoparticles: preparation, characterization and in vitro potential against Candida albicans

    PubMed Central

    Zia, Qamar; Khan, Aijaz Ahmed; Swaleha, Zubair; Owais, Mohammad

    2015-01-01

    In the present study, we developed a self-assembled biodegradable polyglutamic acid (PGA)-based formulation of amphotericin B (AmB) and evaluated its in vitro antifungal potential against Candida albicans. The AmB-loaded PGA nanoparticles were prepared in-house and had a mean size dimension of around 98±2 nm with a zeta potential of −35.2±7.3 mV. Spectroscopic studies revealed that the drug predominantly acquires an aggregated form inside the formulation with an aggregation ratio above 2. The PGA-based AmB formulation was shown to be highly stable in phosphate-buffered saline as well as in serum (only 10%–20% of the drug was released after 10 days). The AmB–PGA nanoparticles were less toxic to red blood cells (<15% lysis at an AmB concentration of 100 μg/mL after 24 hours) when compared with Fungizone®, a commercial antifungal product. An MTT assay showed that the viability of mammalian cells (KB and RAW 264.7) was negligibly affected at AmB concentrations as high as 200 μg/mL. Histopathological examination of mouse kidney revealed no signs of tissue necrosis. The AmB–PGA formulation showed potent antimicrobial activity similar to that of Fungizone against C. albicans. Interestingly, AmB-bearing PGA nanoparticles were found to inhibit biofilm formation to a considerable extent. In summary, AmB–PGA nanoparticles showed highly attenuated toxicity when compared with Fungizone, while retaining equivalent active antifungal properties. This study indicates that the AmB–PGA preparation could be a promising treatment for various fungal infections. PMID:25784804

  16. Inhibition of Candida albicans virulence factors by novel levofloxacin derivatives.

    PubMed

    Shafreen, Raja Mohamed Beema; Raja Mohamed, Beema Shafreen; Muthamil, Subramanian; Subramanian, Muthamil; Pandian, Shunmugiah Karutha; Shunmugiah, Karutha Pandian

    2014-08-01

    Candida albicans is an important opportunistic fungal pathogen, responsible for biofilm associated infections in immunocompromised patients. The aim of the present study was to investigate the antibiofilm properties of novel levofloxacin derivatives on C. albicans biofilms. The levofloxacin derivatives at their Biofilm Inhibitory Concentrations (BIC) were able to inhibit the biofilms of C. albicans, the yeast-to-hyphal transition and were also able to disrupt their mature biofilms. Furthermore, Real-time PCR analysis showed that the expression of ergosterol biosynthesis pathway gene (ERG11) and the efflux pump-encoding genes (CDR1 and MDR1) was decreased upon treatment with the levofloxacin derivatives. The total ergosterol content quantified using UV spectrophotomer showed decrease in ergosterol in the presence of levofloxacin derivatives. Overall, levofloxacin derivatives (6a, 6c and 7d) are capable of inhibiting C. albicans virulence factors. Therefore, these compounds with potential therapeutic implications can be used as new strategy to treat biofilm-related candidal infections. PMID:24723295

  17. Fatty Acid Synthase Impacts the Pathobiology of Candida parapsilosis In Vitro and during Mammalian Infection

    PubMed Central

    Nguyen, Long Nam; Trofa, David; Nosanchuk, Joshua D.

    2009-01-01

    Cytosolic fungal fatty acid synthase is composed of two subunits α and β, which are encoded by Fas1 and Fas2 genes. In this study, the Fas2 genes of the human pathogen Candida parapsilosis were deleted using a modified SAT1 flipper technique. CpFas2 was essential in media lacking exogenous fatty acids and the growth of Fas2 disruptants (Fas2 KO) was regulated by the supplementation of different long chain fatty acids, such as myristic acid (14∶0), palmitic acid (16∶0), and Tween 80, in a dose-specific manner. Lipidomic analysis revealed that Fas2 KO cells were severely restricted in production of unsaturated fatty acids. The Fas2 KO strains were unable to form normal biofilms and were more efficiently killed by murine-like macrophages, J774.16, than the wild type, heterozygous and reconstituted strains. Furthermore, Fas2 KO yeast were significantly less virulent in a systemic murine infection model. The Fas2 KO cells were also hypersensitive to human serum, and inhibition of CpFas2 in WT C. parapsilosis by cerulenin significantly decreased fungal growth in human serum. This study demonstrates that CpFas2 is essential for C. parapsilosis growth in the absence of exogenous fatty acids, is involved in unsaturated fatty acid production, influences fungal virulence, and represents a promising antifungal drug target. PMID:20027295

  18. [Isosorbide dinitrate inhibits in vitro platelet aggregation at submicromolar concentrations].

    PubMed

    Gachet, C; Guillou, J; Moog, S; Cazenave, J P

    1992-04-01

    Nitrate derivatives have in vivo and in vitro platelet anti-aggregant properties in addition to their vasodilatory effects. The mode of action is related to increased intracytoplasmic cyclic GMP concentrations. It has been shown that isosorbide dinitrate (ISDN) has this type of platelet anti-aggregant activity but the reported results about the active concentrations and the inhibited pathways of activation are contradictory. This study was designed to determine whether ISDN has in vitro platelet anti-aggregant activity at low doses and to verify if this effect is selective by aggregation induced by ADP. Finally, a possible potentialisation of the inhibitors due to ISDN was looked for with cyclic nucleotide phosphodiesterase inhibitors and with agents simulating the effect of adenylate cyclase. The results showed that: 1) ISDN had platelet anti-aggregant activity in vitro at concentrations of about 10-7 M, 2) that this effect was not limited to the aggregation induced by ADP as the aggregation induced by PAF-acether was also inhibited by low dose ISDN, 3) of the cyclic nucleotide modulators tested, only quercetine (flavonoide) potentialised the effects of ISDN. PMID:1326933

  19. Natural cell-mediated cytotoxicity against Candida albicans induced by cyclophosphamide: nature of the in vitro cytotoxic effector.

    PubMed Central

    Baccarini, M; Bistoni, F; Puccetti, P; Garaci, E

    1983-01-01

    We have recently reported the in vivo modulation of resistance to experimental Candida albicans infection by cyclophosphamide (150 mg/kg intraperitoneally) in mice and have shown that increased resistance to the microbial challenge occurs 12 to 21 days after treatment with the drug (Bistoni et al., Infect. Immun. 40: 46-55, 1983). The event is accompanied by the appearance of a highly candidacidal cell population in the spleen and the activation of a subpopulation of natural cytotoxic effectors reactive in vitro against YAC-1 tumor cells. We now provide evidence that these anti-YAC-1 cytotoxic effectors are clearly distinct from the cyclophosphamide-induced candidacidal effectors, which seem to belong to a macrophage-monocyte lineage. The enhanced cytotoxic activity induced by cyclophosphamide was not restricted to C. albicans but was also exerted against a panel of Candida strains. PMID:6352489

  20. Identification of the aminocatechol A-3253 as an in vitro poison of DNA topoisomerase I from Candida albicans.

    PubMed Central

    Fostel, J; Montgomery, D

    1995-01-01

    The aminocatechol A-3253 is active against several pathogenic fungi, including Candida albicans, Cryptococcus albidus, and Aspergillus niger. A-3253 interferes with both the in vitro biosynthesis of (1,3)-beta-glucan and the activity of topoisomerases I isolated from Candida spp. It is likely that one or more of the enzymes involved in glucan biosynthesis rather than topoisomerase I is the primary intracellular target of A-3253, since a strain of Saccharomyces cerevisiae lacking topoisomerase I is as susceptible to A-3253 as cells containing wild-type levels of topoisomerase I. However, the interaction of A-3253 with topoisomerase I in vitro is of interest since the Candida topoisomerase is more susceptible to A-3253 than is the topoisomerase I isolated from human HeLa cells. A-3253 is both a reversible inhibitor of topoisomerase I catalysis and a reversible poison of topoisomerase I, and in both reactions the fungal topoisomerase I is more susceptible than the human topoisomerase I to A-3253. In contrast, an earlier study found that the human topoisomerase I is more susceptible than the fungal topoisomerase to camptothecin (J. M. Fostel, D. A. Montgomery, and L. L. Shen, Antimicrob. Agents Chemother. 36:2131-2138, 1992). Taken together with the response to camptothecin, the greater susceptibility of the Candida topoisomerase I to A-3253 suggests that there are structural differences between the human and fungal type I topoisomerases which can likely be exploited to allow for the development of antifungal agents which act against the fungal topoisomerase and which have minimal activity against the human enzyme. PMID:7793856

  1. Inhibition of hemopoiesis in vitro by neuroblastoma-derived gangliosides.

    PubMed

    Sietsma, H; Nijhof, W; Dontje, B; Vellenga, E; Kamps, W A; Kok, J W

    1998-11-01

    Hemopoiesis is disturbed in bone marrow-involving cancers like leukemia and neuroblastoma. Shedding of gangliosides by tumor cells may contribute to this tumor-induced bone marrow suppression. We studied in vitro the inhibitory effects of murine neuroblastoma cells (Neuro-2a and C1300) and their gangliosides on hemopoiesis using normal murine hemopoietic progenitor colony-forming assays. Transwell cultured neuroblastoma cells showed a dose-dependent inhibition on hemopoiesis, indicating that a soluble factor was responsible for this effect. Furthermore, the supernatant of Neuro-2a cultured cells inhibited hemopoietic proliferation and differentiation. To determine whether the inhibitory effect was indeed due to shed gangliosides and not, for instance, caused by cytokines, the effect of DL-threo-1 -phenyl-2-decanoylamino-3-morpholino-1-propanol (DL-PDMP) on Neuro-2a cells was studied. DL-PDMP is a potent inhibitor of glucosylceramide synthase, resulting in inhibition of the synthesis and shedding of gangliosides. The initially observed inhibitory effect of supernatant of Neuro-2a cells was abrogated by culturing these cells for 3 days in the presence of 10 microM DL-PDMP. Moreover, gangliosides isolated from Neuro-2a cell membranes inhibited hemopoietic growth. To determine whether the described phenomena in vitro are a reflection of bone marrow suppression occurring in vivo, gangliosides isolated from plasma of neuroblastoma patients were tested for their effects on human hemopoietic progenitor colony-forming assays. These human neuroblastoma-derived gangliosides inhibited normal erythropoiesis (colony-forming unit-erythroid/burst-forming unit-erythroid) and myelopoiesis (colony-forming unit-granulocyte/macrophage) to a higher extent compared with gangliosides isolated from control plasma. Altogether these results suggest that gangliosides shed by neuroblastoma cells inhibit hemopoiesis and may contribute to the observed bone marrow depression in neuroblastoma

  2. In vitro reversibility of cadmium-induced inhibition of phagocytosis.

    PubMed

    Levy, L; Vredevoe, D L; Cook, G

    1986-12-01

    Cadmium chloride, administered chronically in the drinking water of CBA/H mice, produced a delayed clearance of particles and soluble material bearing Fc fragments (D. W. Knutson, D. L. Vredevoe, K. R. Aoki, and L. Levy, 1980, Immunology, 40, 17-26; D. L. Vredevoe, L. Levy, D. Knutson, G. Cook, and P. Cohen, 1985, Environ. Res. 37, 373-382). The inhibition was reversed upon removal of the cadmium from the water, even though a tissue load of cadmium persisted. An in vitro system was developed to analyze the mechanism of the inhibition. Binding and ingestion of sheep red blood cells (E) treated with IgG (for measurement of Fc receptor activity) or IgM and complement (C) (for measurement of complement receptor activity) were studied in resident and elicited murine peritoneal macrophages in vitro. Elicited macrophages provided the most definitive test system. With this system, there was significant inhibition of ingestion of E-IgG and E-IgMC. Binding of both types of erythrocytes was not inhibited, except at the highest concentration (10(-4) M) of CdCl2 at which binding of only E-IgMC was affected. These effects were reversible upon removal of cadmium. Migration of Fc and C receptors on the macrophage surface was not significantly affected by cadmium. In general, cadmium did not alter the expression or the binding of Fc or C receptors on macrophages. The mechanism for delayed clearance appears to be due to inhibited internalization of the particles. This is consistent with the interpretation that cadmium is a membrane active agent. PMID:3780638

  3. Recruitment of Perisomatic Inhibition during Spontaneous Hippocampal Activity In Vitro

    PubMed Central

    Molter, Colin; Mehidi, Amine; Szabadics, Janos; Leinekugel, Xavier

    2013-01-01

    It was recently shown that perisomatic GABAergic inhibitory postsynaptic potentials (IPSPs) originating from basket and chandelier cells can be recorded as population IPSPs from the hippocampal pyramidal layer using extracellular electrodes (eIPSPs). Taking advantage of this approach, we have investigated the recruitment of perisomatic inhibition during spontaneous hippocampal activity in vitro. Combining intracellular and extracellular recordings from pyramidal cells and interneurons, we confirm that inhibitory signals generated by basket cells can be recorded extracellularly, but our results suggest that, during spontaneous activity, eIPSPs are mostly confined to the CA3 rather than CA1 region. CA3 eIPSPs produced the powerful time-locked inhibition of multi-unit activity expected from perisomatic inhibition. Analysis of the temporal dynamics of spike discharges relative to eIPSPs suggests significant but moderate recruitment of excitatory and inhibitory neurons within the CA3 network on a 10 ms time scale, within which neurons recruit each other through recurrent collaterals and trigger powerful feedback inhibition. Such quantified parameters of neuronal interactions in the hippocampal network may serve as a basis for future characterisation of pathological conditions potentially affecting the interactions between excitation and inhibition in this circuit. PMID:23805227

  4. Recruitment of Perisomatic Inhibition during Spontaneous Hippocampal Activity In Vitro.

    PubMed

    Beyeler, Anna; Retailleau, Aude; Molter, Colin; Mehidi, Amine; Szabadics, Janos; Leinekugel, Xavier

    2013-01-01

    It was recently shown that perisomatic GABAergic inhibitory postsynaptic potentials (IPSPs) originating from basket and chandelier cells can be recorded as population IPSPs from the hippocampal pyramidal layer using extracellular electrodes (eIPSPs). Taking advantage of this approach, we have investigated the recruitment of perisomatic inhibition during spontaneous hippocampal activity in vitro. Combining intracellular and extracellular recordings from pyramidal cells and interneurons, we confirm that inhibitory signals generated by basket cells can be recorded extracellularly, but our results suggest that, during spontaneous activity, eIPSPs are mostly confined to the CA3 rather than CA1 region. CA3 eIPSPs produced the powerful time-locked inhibition of multi-unit activity expected from perisomatic inhibition. Analysis of the temporal dynamics of spike discharges relative to eIPSPs suggests significant but moderate recruitment of excitatory and inhibitory neurons within the CA3 network on a 10 ms time scale, within which neurons recruit each other through recurrent collaterals and trigger powerful feedback inhibition. Such quantified parameters of neuronal interactions in the hippocampal network may serve as a basis for future characterisation of pathological conditions potentially affecting the interactions between excitation and inhibition in this circuit. PMID:23805227

  5. In vitro studies of activities of some antifungal agents against Candida albicans ATCC 10231 by the turbidimetric method.

    PubMed Central

    Blanco, M T; Pérez-Giraldo, C; Blanco, J; Morán, F J; Hurtado, C; Gómez-García, A C

    1992-01-01

    Different criteria (the drug concentration which inhibited 50% of growth [IC1/2], the lowest drug concentration at which growth was just less than 30% of that in a positive control well [IC30], the visual inhibitory concentration [ICv], and the minimum fungicidal concentration [MFC]) were applied to study the effects of some antifungal agents against Candida albicans. Amphotericin B, flucytosine, and bifonazole produced total growth inhibition. Clotrimazole, itraconazole, ketoconazole, and miconazole produced partial growth inhibition. The values of IC1/2 and IC30 were similar for all agents and avoided the problems of partial inhibition; the values of ICv and MFC were higher than those of IC1/2 and IC30. PMID:1503456

  6. Natural Polyphenols Inhibit Lysine-Specific Demethylase-1 in vitro.

    PubMed

    Abdulla, Arian; Zhao, Xiaoping; Yang, Fajun

    2013-03-01

    Natural polyphenols, such as resveratrol, have beneficial functions on major human diseases such as cancer, diabetes, and cardiovascular disease. Besides acting as antioxidants, some of these polyphenols can also target proteins to modulate specific biological pathways. The lysine-specific histone demethylase LSD1 plays important roles in cell growth, differentiation and nutrient metabolism. Here, we studied the effect of natural polyphenols resveratrol, curcumin, quercetin and analogs on LSD1. Using in vitro LSD1 enzymatic assays, we show that resveratrol, curcumin and quercetin displayed a potent inhibitory effect on the LSD1 activity and were more potent than the known LSD1 inhibitor trans-2-phenylcyclopropylamine (TCP). The new function of resveratrol, curcumin and quercetin is independent of their antioxidant properties, as other antioxidants had no effect on LSD1 under the similar conditions. In C2C12 fibroblasts, resveratrol and curcumin can efficiently inhibit myogenic expression and differentiation, for which LSD1 is required. Thus, our study has identified LSD1 as a novel target of bioactive natural compounds, such as resveratrol, curcumin and quercetin, and such finding suggests that LSD1 inhibition can at least partially contribute to some of the previously observed beneficial effects of these compounds. PMID:23662249

  7. Natural Polyphenols Inhibit Lysine-Specific Demethylase-1 in vitro

    PubMed Central

    Abdulla, Arian; Zhao, Xiaoping; Yang, Fajun

    2013-01-01

    Natural polyphenols, such as resveratrol, have beneficial functions on major human diseases such as cancer, diabetes, and cardiovascular disease. Besides acting as antioxidants, some of these polyphenols can also target proteins to modulate specific biological pathways. The lysine-specific histone demethylase LSD1 plays important roles in cell growth, differentiation and nutrient metabolism. Here, we studied the effect of natural polyphenols resveratrol, curcumin, quercetin and analogs on LSD1. Using in vitro LSD1 enzymatic assays, we show that resveratrol, curcumin and quercetin displayed a potent inhibitory effect on the LSD1 activity and were more potent than the known LSD1 inhibitor trans-2-phenylcyclopropylamine (TCP). The new function of resveratrol, curcumin and quercetin is independent of their antioxidant properties, as other antioxidants had no effect on LSD1 under the similar conditions. In C2C12 fibroblasts, resveratrol and curcumin can efficiently inhibit myogenic expression and differentiation, for which LSD1 is required. Thus, our study has identified LSD1 as a novel target of bioactive natural compounds, such as resveratrol, curcumin and quercetin, and such finding suggests that LSD1 inhibition can at least partially contribute to some of the previously observed beneficial effects of these compounds. PMID:23662249

  8. In vitro inhibition of mitochondrial respiratory rate by antidepressants.

    PubMed

    Hroudová, Jana; Fišar, Zdeněk

    2012-09-18

    Mitochondria represent a possible drug target with unexplored therapeutic and toxicological potential. The possibility was suggested that antidepressants, mood stabilizers and other drugs may show some therapeutic and/or toxic effects through their action on mitochondrial functions. There are no sufficient data about the effect of these drugs on mitochondrial respiration in the brain. We investigated the in vitro effects of amitriptyline, fluoxetine, tianeptine, ketamine, lithium, valproate, olanzapine, chlorpromazine and propranolol on mitochondrial respiration in crude mitochondrial fractions of pig brains. Respiration was energized using substrates of complex I or complex II and dose dependent drug-induced changes in mitochondrial respiratory rate were measured by high-resolution respirometry. Antidepressants, but not mood stabilizers, ketamine and propranolol were found to inhibit mitochondrial respiratory rate. The effective dose of antidepressants reaching half the maximal respiratory rate was in the range of 0.07-0.46 mmol/L. Partial inhibition was found for all inhibitors. Differences between individual drugs with similar physicochemical properties indicate selectivity of drug-induced changes in mitochondrial respiratory rate. Our findings suggest that mood stabilizers do not interfere with brain mitochondrial respiration, whereas direct mitochondrial targeting is involved in mechanisms of action of pharmacologically different antidepressants. PMID:22842584

  9. CYP2C19 inhibition: the impact of substrate probe selection on in vitro inhibition profiles.

    PubMed

    Foti, Robert S; Wahlstrom, Jan L

    2008-03-01

    Understanding the potential for cytochrome P450 (P450)-mediated drug-drug interactions is a critical part of the drug discovery process. Factors such as nonspecific binding, atypical kinetics, poor effector solubility, and varying ratios of accessory proteins may alter the kinetic behavior of an enzyme and subsequently confound the extrapolation of in vitro data to the human situation. The architecture of the P450 active site and the presence of multiple binding regions within the active site may also confound in vitro-in vivo extrapolation, as inhibition profiles may be dependent on a specific inhibitor-substrate interaction. In these studies, the inhibition profiles of a set of 24 inhibitors were paneled against the CYP2C19 substrate probes (S)-mephenytoin, (R)-omeprazole, (S)-omeprazole, and (S)-fluoxetine, on the basis of their inclusion in recent U.S. Food and Drug Administration guidance for in vitro drug-drug interactions with CYP2C19. (S)-Mephenytoin was inhibited an average of 5.6-fold more potently than (R)- or (S)-omeprazole and 9.2-fold more potently than (S)-fluoxetine. Hierarchical clustering of the inhibition data suggested three substrate probe groupings, with (S)-mephenytoin exhibiting the largest difference from the rest of the substrate probes, (S)-fluoxetine exhibiting less difference from (S)-mephenytoin and the omeprazoles and (R)- and (S)-omeprazole exhibiting minimal differences from each other. Predictions of in vivo inhibition potency based on the in vitro data suggest that most drug-drug interactions will be identified by either (S)-mephenytoin or omeprazole, although the expected magnitude of the interaction may vary depending on the chosen substrate probe. PMID:18048485

  10. Reduced inhibition of Candida albicans adhesion by saliva from patients receiving oral cancer therapy.

    PubMed Central

    Umazume, M; Ueta, E; Osaki, T

    1995-01-01

    The effect of saliva on the adhesion of Candida albicans to epithelial cells was examined in vitro by using saliva from healthy controls and patients with oral squamous cell carcinoma. The adhesion of C. albicans to established epithelial tumor cells was reduced by 40% by salivary treatment of the C. albicans or epithelial cells. The inhibitory activity of saliva was almost completely abolished by anti-secretory immunoglobulin A antibody, concanavalin A, and mannose. Compared with saliva from healthy individuals, that from patients who had received chemoradiotherapy for oral carcinoma showed reduced suppression of C. albicans adhesion, which accompanied decreased salivary secretory immunoglobulin A and lactoferrin concentrations. A greater number of C. albicans cells adhered to buccal cells obtained from patients who had received chemoradiotherapy than to those from healthy individuals. Treatment of either epithelial cells or C. albicans with anticancer drugs induced an increase in adherence of epithelial cells and yeast cells. In contrast, concanavalin A- and mannose-pretreated C. albicans exhibited reduced adhesion to epithelial cells. No further decrease of C. albicans adhesion was observed when both epithelial cells and yeast phase C. albicans were treated with mannose. In conclusion, the inhibition of C. albicans adhesion by saliva depends largely on mannose residues on salivary glycoproteins and mannose is one of the binding ligands on both C. albicans and epithelial cells. In addition, anticancer therapy may induce oral C. albicans overgrowth by decreasing salivation and the concentrations of glycoproteins in saliva inhibiting C. albicans adhesion and by increasing the adhesive properties of both C. albicans and oral epithelial cells. PMID:7714204

  11. Leptin inhibits testosterone secretion from adult rat testis in vitro.

    PubMed

    Tena-Sempere, M; Pinilla, L; González, L C; Diéguez, C; Casanueva, F F; Aguilar, E

    1999-05-01

    Leptin, the product of the ob gene, has emerged recently as a pivotal signal in the regulation of fertility. Although the actions of leptin in the control of reproductive function are thought to be exerted mainly at the hypothalamic level, the potential direct effects of leptin at the pituitary and gonadal level have been poorly characterised. In the present study, we first assessed the ability of leptin to regulate testicular testosterone secretion in vitro. Secondly, we aimed to evaluate whether leptin can modulate basal gonadotrophin and prolactin (PRL) release by incubated hemi-pituitaries from fasted male rats. To attain the first goal, testicular slices from prepubertal and adult rats were incubated with increasing concentrations (10(-9)-10(-7) M) of recombinant leptin. Assuming that in vitro testicular responsiveness to leptin may be dependent on the background leptin levels, testicular tissue from both food-deprived and normally-fed animals was used. Furthermore, leptin modulation of stimulated testosterone secretion was evaluated by incubation of testicular samples with different doses of leptin in the presence of 10 IU human chorionic gonadotrophin (hCG). In addition, analysis of leptin actions on pituitary function was carried out using hemi-pituitaries from fasted adult male rats incubated in the presence of increasing concentrations (10(-9)-10(-7) M) of recombinant leptin. Serum testosterone levels, and basal and hCG-stimulated testosterone secretion by incubated testicular tissue were significantly decreased by fasting in prepubertal and adult male rats. However, a significant reduction in circulating LH levels was only evident in adult fasted rats. Doses of 10(-9)-10(-7) M leptin had no effect on basal or hCG-stimulated testosterone secretion by testes from prepubertal rats, regardless of the nutritional state of the donor animal. In contrast, leptin significantly decreased basal and hCG-induced testosterone secretion by testes from fasted and fed

  12. Further evidence that naphthoquinone inhibits Toxoplasma gondii growth in vitro.

    PubMed

    da Silva, Luciana Lemos Rangel; Portes, Juliana de Araujo; de Araújo, Marlon Heggdorne; Silva, Jéssica Lays Sant'ana; Rennó, Magdalena Nascimento; Netto, Chaquip Daher; da Silva, Alcides José Monteiro; Costa, Paulo Roberto Ribeiro; De Souza, Wanderley; Seabra, Sergio Henrique; DaMatta, Renato Augusto

    2015-12-01

    Toxoplasmosis is a widely disseminated disease caused by Toxoplasma gondii, an intracellular protozoan parasite. Standard treatment causes many side effects, such as depletion of bone marrow cells, skin rashes and gastrointestinal implications. Therefore, it is necessary to find chemotherapeutic alternatives for the treatment of this disease. It was shown that a naphthoquinone derivative compound is active against T. gondii, RH strain, with an IC50 around 2.5 μM. Here, three different naphthoquinone derivative compounds with activity against leukemia cells and breast carcinoma cell were tested against T. gondii (RH strain) infected LLC-MK2 cell line. All the compounds were able to inhibit parasite growth in vitro, but one of them showed an IC50 activity below 1 μM after 48 h of treatment. The compounds showed low toxicity to the host cell. In addition, these compounds were able to induce tachyzoite-bradyzoite conversion confirmed by morphological changes, Dolichus biflorus lectin cyst wall labeling and characterization of amylopectin granules in the parasites by electron microscopy analysis using the Thierry technique. Furthermore, the compounds induced alterations on the ultrastructure of the parasite. Taken together, our results point to the naphthoquinone derivative (LQB 151) as a potential compound for the development of new drugs for the treatment of toxoplasmosis. PMID:26335616

  13. Biofilm formation by Candida species on silicone surfaces and latex pacifier nipples: an in vitro study.

    PubMed

    da Silveira, Luiz Cezar; Charone, Senda; Maia, Lucianne Cople; Soares, Rosangela Maria de Araújo; Portela, Maristela Barbosa

    2009-01-01

    The present study assessed the growth and development of biofilm formation by isolates of C. albicans, C. glabrata and C. parapsilosis on silicone and latex pacifier nipples. The silicone and latex surfaces were evaluated by scanning electronic microscopy (SEM). The plastic component of the nipple also seems to be an important factor regarding the biofilm formation by Candida spp. The biofilm growth was measured using the MTT reduction reaction. C. albicans was found to have a slightly greater capacity of forming biofilm compared to the other Candida species. Analysis of the pattern of biofilm development by C. albicans, C. glabrata and C. parapsilosis on latex and silicon pacifier shields showed an increased biofilm formation regarding the latter substrate. Silicone was shown to be more resistant to fungal colonization, particularly in the case of C. parapsilosis, despite the lack of any statistically significant differences (P > 0.05). In addition, silicone has a smoother surface compared to latex, whose surface was found to be rugose and irregular. PMID:19476097

  14. Irreversible electropermeabilization of the human pathogen Candida albicans: an in-vitro experimental study.

    PubMed

    Novickij, Vitalij; Grainys, Audrius; Svediene, Jurgita; Markovskaja, Svetlana; Paskevicius, Algimantas; Novickij, Jurij

    2015-02-01

    Pathogenic fungi cause many life-threatening infections, especially among individuals with immune system dysfunction. The antifungal drugs commonly used to suppress fungal pathogens can result in long-lasting and toxic therapy. In this work, irreversible electropermeabilization was used to investigate the dynamics of the decrease in Candida albicans colony vitality after application of a pulsed electric field (PEF) and use of antifungal drugs. The fungi were subjected to single 250-µs to 2-ms (0.5-2.5 kV/cm) pulses or repeated short 5-µs pulses, and efficacy was compared. It was shown that electropermeabilization combined with antifungal agents results in rapid and more effective treatment, eliminating more than 90% of C. albicans colony-forming units in a single procedure, which is advantageous in biomedicine. It was also observed that, because of application of PEF and use of the antifungal agents, the Candida cells form cell aggregates and average live cell size is reduced by as much as 53%. PMID:25381646

  15. Activity of fluconazole (UK 49,858) and ketoconazole against Candida albicans in vitro and in vivo.

    PubMed Central

    Rogers, T E; Galgiani, J N

    1986-01-01

    Fluconazole (UK 49,858), a new orally administered bis-triazole, was compared with ketoconazole for activity in synthetic broth dilution susceptibility tests against Candida albicans and also in treatment of experimental systemic candidal infections in rats. In vitro studies indicated that fluconazole activity is less sensitive to acidic medium than is that of ketoconazole. At physiologic pH, fluconazole was approximately 16-fold less active than ketoconazole against 35 representative isolates of C. albicans. Two additional isolates (K-1 and K-3) recovered from patients who had failed ketoconazole therapy were 32- to 64-fold more resistant than the median of each drug for other isolates. In animal studies, fluconazole was very effective in prolonging survival of rats infected with a representative candidal strain. With an inoculum sufficient to kill 29 of 38 sham-treated animals, only 1 of 18 animals treated with 0.5 mg of fluconazole per kg per day died compared with 13 of 20 animals treated with 10.0 mg of ketoconazole per kg per day. However, when similar fluconazole treatment was administered to rats infected with the more resistant strain, K-1, no prolongation of survival was found. Thus, in vivo and in vitro results between strains correlated well for fluconazole. However, in comparing results between drugs, ketoconazole was 16-fold more active in vitro and fluconazole was 20-fold more active in vivo. This discrepancy may be due to drug distribution, modes of drug metabolism, or other pharmacologic differences between the two agents. PMID:3022641

  16. Candida tropicalis from veterinary and human sources shows similar in vitro hemolytic activity, antifungal biofilm susceptibility and pathogenesis against Caenorhabditis elegans.

    PubMed

    Brilhante, Raimunda Sâmia Nogueira; Oliveira, Jonathas Sales de; Evangelista, Antônio José de Jesus; Serpa, Rosana; Silva, Aline Lobão da; Aguiar, Felipe Rodrigues Magalhães de; Pereira, Vandbergue Santos; Castelo-Branco, Débora de Souza Collares Maia; Pereira-Neto, Waldemiro Aquino; Cordeiro, Rossana de Aguiar; Sidrim, José Júlio Costa; Rocha, Marcos Fábio Gadelha

    2016-08-30

    The aim of this study was to evaluate the in vitro hemolytic activity and biofilm antifungal susceptibility of veterinary and human Candida tropicalis strains, as well as their pathogenesis against Caenorhabditis elegans. Twenty veterinary isolates and 20 human clinical isolates of C. tropicalis were used. The strains were evaluated for their hemolytic activity and biofilm production. Biofilm susceptibility to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin was assessed using broth microdilution assay. The in vivo evaluation of strain pathogenicity was investigated using the nematode C. elegans. Hemolytic factor was observed in 95% of the strains and 97.5% of the isolates showed ability to form biofilm. Caspofungin and amphotericin B showed better results than azole antifungals against mature biofilms. Paradoxical effect on mature biofilm metabolic activity was observed at elevated concentrations of caspofungin (8-64μg/mL). Azole antifungals were not able to inhibit mature C. tropicalis biofilms, even at the higher tested concentrations. High mortality rates of C. elegans were observed when the worms were exposed to with C. tropicalis strains, reaching up to 96%, 96h after exposure of the worms to C. tropicalis strains. These results reinforce the high pathogenicity of C. tropicalis from veterinary and human sources and show the effectiveness of caspofungin and amphotericin B against mature biofilms of this species. PMID:27527785

  17. In Vitro Activity of Miltefosine against Candida albicans under Planktonic and Biofilm Growth Conditions and In Vivo Efficacy in a Murine Model of Oral Candidiasis.

    PubMed

    Vila, Taissa Vieira Machado; Chaturvedi, Ashok K; Rozental, Sonia; Lopez-Ribot, Jose L

    2015-12-01

    The generation of a new antifungal against Candida albicans biofilms has become a major priority, since biofilm formation by this opportunistic pathogenic fungus is usually associated with an increased resistance to azole antifungal drugs and treatment failures. Miltefosine is an alkyl phospholipid with promising antifungal activity. Here, we report that, when tested under planktonic conditions, miltefosine displays potent in vitro activity against multiple fluconazole-susceptible and -resistant C. albicans clinical isolates, including isolates overexpressing efflux pumps and/or with well-characterized Erg11 mutations. Moreover, miltefosine inhibits C. albicans biofilm formation and displays activity against preformed biofilms. Serial passage experiments confirmed that miltefosine has a reduced potential to elicit resistance, and screening of a library of C. albicans transcription factor mutants provided additional insight into the activity of miltefosine against C. albicans growing under planktonic and biofilm conditions. Finally, we demonstrate the in vivo efficacy of topical treatment with miltefosine in the murine model of oropharyngeal candidiasis. Overall, our results confirm the potential of miltefosine as a promising antifungal drug candidate, in particular for the treatment of azole-resistant and biofilm-associated superficial candidiasis. PMID:26416861

  18. In vitro activities of voriconazole (UK-109,496) against fluconazole-susceptible and -resistant Candida albicans isolates from oral cavities of patients with human immunodeficiency virus infection.

    PubMed Central

    Ruhnke, M; Schmidt-Westhausen, A; Trautmann, M

    1997-01-01

    The susceptibility of Candida albicans to a new antifungal triazole, voriconazole (UK-109,496), was investigated in 105 isolates obtained from the oral cavities of patients with human immunodeficiency virus (HIV) infection to study this drug's activity against fluconazole-susceptible and -resistant isolates. MICs were determined by a broth microdilution technique according to document M27-T from the National Committee for Clinical Laboratory Standards and by using a broth microdilution technique and a synthetic high-resolution medium. These antifungal susceptibility testing methods showed high levels of agreement (93% for fluconazole and 86% for voriconazole). Data from in vitro studies showed that voriconazole has good activity against fluconazole-susceptible and -resistant C. albicans isolates; the MICs at which 90% of all isolates were inhibited were 0.19 to 0.39 microgram/ml. We found that for isolates for which fluconazole MICs were high, voriconazole MICs were proportionally higher than those for fluconazole-susceptible C.albicans (P < 0.001). Pretreatment isolates from six patients with fluconazole-refractory esophageal candidiasis were included in the study. For these isolates the MICs were < or = 0.39 microgram/ml, and all patients responded to voriconazole. These results suggest that voriconazole is effective even in the treatment of fluconazole-refractory esophageal candidiasis and should be studied further to determine its clinical relevance in patients with HIV infection. PMID:9055995

  19. Specific Inhibition of Histone Deacetylase 8 Reduces Gene Expression and Production of Proinflammatory Cytokines in Vitro and in Vivo*

    PubMed Central

    Li, Suzhao; Fossati, Gianluca; Marchetti, Carlo; Modena, Daniela; Pozzi, Pietro; Reznikov, Leonid L.; Moras, Maria Luisa; Azam, Tania; Abbate, Antonio; Mascagni, Paolo; Dinarello, Charles A.

    2015-01-01

    ITF2357 (generic givinostat) is an orally active, hydroxamic-containing histone deacetylase (HDAC) inhibitor with broad anti-inflammatory properties, which has been used to treat children with systemic juvenile idiopathic arthritis. ITF2357 inhibits both Class I and II HDACs and reduces caspase-1 activity in human peripheral blood mononuclear cells and the secretion of IL-1β and other cytokines at 25–100 nm; at concentrations >200 nm, ITF2357 is toxic in vitro. ITF3056, an analog of ITF2357, inhibits only HDAC8 (IC50 of 285 nm). Here we compared the production of IL-1β, IL-1α, TNFα, and IL-6 by ITF2357 with that of ITF3056 in peripheral blood mononuclear cells stimulated with lipopolysaccharide (LPS), heat-killed Candida albicans, or anti-CD3/anti-CD28 antibodies. ITF3056 reduced LPS-induced cytokines from 100 to 1000 nm; at 1000 nm, the secretion of IL-1β was reduced by 76%, secretion of TNFα was reduced by 88%, and secretion of IL-6 was reduced by 61%. The intracellular levels of IL-1α were 30% lower. There was no evidence of cell toxicity at ITF3056 concentrations of 100–1000 nm. Gene expression of TNFα was markedly reduced (80%), whereas IL-6 gene expression was 40% lower. Although anti-CD3/28 and Candida stimulation of IL-1β and TNFα was modestly reduced, IFNγ production was 75% lower. Mechanistically, ITF3056 reduced the secretion of processed IL-1β independent of inhibition of caspase-1 activity; however, synthesis of the IL-1β precursor was reduced by 40% without significant decrease in IL-1β mRNA levels. In mice, ITF3056 reduced LPS-induced serum TNFα by 85% and reduced IL-1β by 88%. These data suggest that specific inhibition of HDAC8 results in reduced inflammation without cell toxicity. PMID:25451941

  20. Lipopeptides from Bacillus strain AR2 inhibits biofilm formation by Candida albicans.

    PubMed

    Rautela, Ria; Singh, Anil Kumar; Shukla, Abha; Cameotra, Swaranjit Singh

    2014-05-01

    The ability of the human fungal pathogen Candida albicans to reversibly switch between different morphological forms and establish biofilms is crucial for establishing infection. Targeting phenotypic plasticity and biofilm formation in C. albicans represents a new concept for antifungal drug discovery. The present study evaluated the influence of cyclic lipopeptide biosurfactant produced by Bacillus amyloliquefaciens strain AR2 on C. albicans biofilms. The biosurfactant was characterized as a mixture of iturin and fengycin by MALDI-TOF and amino acid analysis. The biosurfactant exhibited concentration dependent growth inhibition and fungicidal activity. The biosurfactant at sub-minimum growth inhibition concentration decreased cell surface hydrophobicity, hindered germ tube formation and reduced the mRNA expression of hyphae-specific gene HWP1 and ALS3 without exhibiting significant growth inhibition. The biosurfactants inhibited biofilm formation in the range of 46-100 % depending upon the concentration and Candida strains. The biosurfactant treatment dislodged 25-100 % of preformed biofilm from polystyrene plates. The biosurfactant retained its antifungal and antibiofilm activity even after exposure to extreme temperature. By virtue of the ability to inhibit germ tube and biofilm formation, two important traits of C. albicans involved in establishing infection, lipopeptides from strain AR2 may represent a potential candidate for developing heat stable anti-Candida drugs. PMID:24623107

  1. Acetylcholine Protects against Candida albicans Infection by Inhibiting Biofilm Formation and Promoting Hemocyte Function in a Galleria mellonella Infection Model.

    PubMed

    Rajendran, Ranjith; Borghi, Elisa; Falleni, Monica; Perdoni, Federica; Tosi, Delfina; Lappin, David F; O'Donnell, Lindsay; Greetham, Darren; Ramage, Gordon; Nile, Christopher

    2015-08-01

    Both neuronal acetylcholine and nonneuronal acetylcholine have been demonstrated to modulate inflammatory responses. Studies investigating the role of acetylcholine in the pathogenesis of bacterial infections have revealed contradictory findings with regard to disease outcome. At present, the role of acetylcholine in the pathogenesis of fungal infections is unknown. Therefore, the aim of this study was to determine whether acetylcholine plays a role in fungal biofilm formation and the pathogenesis of Candida albicans infection. The effect of acetylcholine on C. albicans biofilm formation and metabolism in vitro was assessed using a crystal violet assay and phenotypic microarray analysis. Its effect on the outcome of a C. albicans infection, fungal burden, and biofilm formation were investigated in vivo using a Galleria mellonella infection model. In addition, its effect on modulation of host immunity to C. albicans infection was also determined in vivo using hemocyte counts, cytospin analysis, larval histology, lysozyme assays, hemolytic assays, and real-time PCR. Acetylcholine was shown to have the ability to inhibit C. albicans biofilm formation in vitro and in vivo. In addition, acetylcholine protected G. mellonella larvae from C. albicans infection mortality. The in vivo protection occurred through acetylcholine enhancing the function of hemocytes while at the same time inhibiting C. albicans biofilm formation. Furthermore, acetylcholine also inhibited inflammation-induced damage to internal organs. This is the first demonstration of a role for acetylcholine in protection against fungal infections, in addition to being the first report that this molecule can inhibit C. albicans biofilm formation. Therefore, acetylcholine has the capacity to modulate complex host-fungal interactions and plays a role in dictating the pathogenesis of fungal infections. PMID:26092919

  2. Acetylcholine Protects against Candida albicans Infection by Inhibiting Biofilm Formation and Promoting Hemocyte Function in a Galleria mellonella Infection Model

    PubMed Central

    Rajendran, Ranjith; Borghi, Elisa; Falleni, Monica; Perdoni, Federica; Tosi, Delfina; Lappin, David F.; O'Donnell, Lindsay; Greetham, Darren; Ramage, Gordon

    2015-01-01

    Both neuronal acetylcholine and nonneuronal acetylcholine have been demonstrated to modulate inflammatory responses. Studies investigating the role of acetylcholine in the pathogenesis of bacterial infections have revealed contradictory findings with regard to disease outcome. At present, the role of acetylcholine in the pathogenesis of fungal infections is unknown. Therefore, the aim of this study was to determine whether acetylcholine plays a role in fungal biofilm formation and the pathogenesis of Candida albicans infection. The effect of acetylcholine on C. albicans biofilm formation and metabolism in vitro was assessed using a crystal violet assay and phenotypic microarray analysis. Its effect on the outcome of a C. albicans infection, fungal burden, and biofilm formation were investigated in vivo using a Galleria mellonella infection model. In addition, its effect on modulation of host immunity to C. albicans infection was also determined in vivo using hemocyte counts, cytospin analysis, larval histology, lysozyme assays, hemolytic assays, and real-time PCR. Acetylcholine was shown to have the ability to inhibit C. albicans biofilm formation in vitro and in vivo. In addition, acetylcholine protected G. mellonella larvae from C. albicans infection mortality. The in vivo protection occurred through acetylcholine enhancing the function of hemocytes while at the same time inhibiting C. albicans biofilm formation. Furthermore, acetylcholine also inhibited inflammation-induced damage to internal organs. This is the first demonstration of a role for acetylcholine in protection against fungal infections, in addition to being the first report that this molecule can inhibit C. albicans biofilm formation. Therefore, acetylcholine has the capacity to modulate complex host-fungal interactions and plays a role in dictating the pathogenesis of fungal infections. PMID:26092919

  3. In vitro antifungal activity of baicalin against Candida albicans biofilms via apoptotic induction.

    PubMed

    Wang, TianMing; Shi, GaoXiang; Shao, Jing; Wu, DaQiang; Yan, YuanYuan; Zhang, MengXiang; Cui, YanYan; Wang, ChangZhong

    2015-10-01

    The aim of this study was to investigate the antifungal activity of baicalin and its potential mechanism of action against Candida albicans biofilms. The standard techniques including microdilution method and checkerboard assay were employed to evaluate the susceptibilities of baicalin alone and in combination with fluconazole against planktonic and biofilm cells of C. albicans. Transmission electron microscope (TEM), scanning electron microscope (SEM), fluorescent microscope and flow cytometry were used to assess the apoptotic incidences induced by baicalin in biofilm cells. The expressions of four genes (RAS1, CAP1, PDE2 and TPK1) related to Ras-cAMP-PKA pathway were also analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The results showed that minimum inhibitory concentration (MIC) and sessile minimum inhibitory concentration (SMIC50) of baicalin were 500 and 2000 μg/mL with fractional inhibitory concentration indexs (FICIs) ranging from 0.28 to 0.75. A series of events related to apoptosis were observed in baicalin-treated C. albicans biofilms, including extensive chromatin condensation along the nuclear envelope, ROS accumulation, MMP reduction, PS externalization, nuclear fragmentation, chromatin condensation, metacaspase activation and Cyt C release. Additionally, the expressions of RAS1 and TPK1 were up-regulated by 3.2 and 2.9 folds respectively, while those of CAP1 and PDE2 were down-regulated by 3.3 and 6.6 folds respectively after exposure to baicalin in biofilm cells. In conclusion, baicalin can suppress the development of C. albicans biofilms most likely due to inducing cell death via apoptosis. PMID:26169236

  4. In vitro activity of essential oils extracted from condiments against fluconazole-resistant and -sensitive Candida glabrata.

    PubMed

    Soares, I H; Loreto, É S; Rossato, L; Mario, D N; Venturini, T P; Baldissera, F; Santurio, J M; Alves, S H

    2015-09-01

    In the present study, the antifungal activity of essential oils obtained from Origanum vulgare (oregano), Cinnamomum zeylanicum (cinnamon), Lippia graveolens (Mexican oregano), Thymus vulgaris (thyme), Salvia officinalis (sage), Rosmarinus officinalis (rosemary), Ocimum basilicum (basil) and Zingiber officinale (ginger) were assessed against Candida glabrata isolates. One group contained 30 fluconazole-susceptible C. glabrata isolates, and the second group contained fluconazole-resistant isolates derived from the first group after the in vitro induction of fluconazole-resistance, for a total of 60 tested isolates. The broth microdilution methodology was used. Concentrations of 50μg/mL, 100μg/mL, 200μg/mL, 400μg/mL, 800μg/mL, 1600μg/mL and 3200μg/mL of the essential oils were used, and the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined. Thyme, sage, rosemary, basil and ginger essential oils showed no antifungal activity at the tested concentrations. Antimicrobial activity less than or equal to 3200μg/mL was observed for oregano, Mexican oregano and cinnamon essential oils. Both the oregano and Mexican oregano essential oils showed high levels of antifungal activity against the fluconazole-susceptible C. glabrata group, whereas the cinnamon essential oil showed the best antifungal activity against the fluconazole-resistant C. glabrata isolates. PMID:26281965

  5. An In Vitro Model for Oral Mixed Biofilms of Candida albicans and Streptococcus gordonii in Synthetic Saliva

    PubMed Central

    Montelongo-Jauregui, Daniel; Srinivasan, Anand; Ramasubramanian, Anand K.; Lopez-Ribot, Jose L.

    2016-01-01

    As a member of the normal human oral microbiota, the fungus Candida albicans is often found in association with Streptococcus gordonii, a member of dental plaque forming bacteria. Evidence suggests that S. gordonii serves as a facilitator of C. albicans adherence to dental tissues, which represents a clinically relevant problem, particularly for immunocompromised individuals that could subsequently develop fungal infections. In this study we describe the development of a relatively simple and economical in vitro model that allows for the growth of mixed bacterial/fungal biofilms in 96-well microtiter plates. We have applied this method to test and compare the growth characteristics of single and dual species biofilms in traditional microbiological media versus a synthetic saliva medium (basal medium mucin, BMM) that more closely resembles physiological conditions within the oral cavity. Results indicated a synergistic effect for the formation of biofilms when both microorganisms were seeded together under all conditions tested. The structural and architectural features of the resulting biofilms were further characterized using scanning electron microscopy and confocal scanning laser microscopy. We also performed drug susceptibility assays against single and mixed species biofilms using commonly used antifungals and antibacterial antibiotics, both in monotherapy and in combination therapy, for a direct comparison of resistance against antimicrobial treatment. As expected, mixed species biofilms displayed higher levels of resistance to antimicrobial treatment at every dose tested in both traditional media and BMM synthetic saliva, as compared to single-species biofilms. PMID:27242712

  6. Antifungal Effect of Lavender Essential Oil (Lavandula angustifolia) and Clotrimazole on Candida albicans: An In Vitro Study

    PubMed Central

    Behmanesh, Fereshteh; Pasha, Hajar; Sefidgar, Ali Asghar; Taghizadeh, Mohsen; Moghadamnia, Ali Akbar; Adib Rad, Hajar; Shirkhani, Leyla

    2015-01-01

    Background. The treatment of candidiasis infections is an important problem in the health care system. This study aimed to investigate the in vitro effect of lavender essential oil and clotrimazole on isolated C. albicans from vaginal candidiasis. Materials and Methods. In this clinical trial, C. albicans isolated from the vaginal discharge samples was obtained. Results. The pairwise comparison showed that lavender and clotrimazole had a significant difference; this difference in the lavender group was lower than clotrimazole. But, after 48 hours, there was no difference seen between groups. There was a significant difference between clotrimazole and DMSO groups. Comparing the changes between groups based on the same dilution, at 24 h and 48 h in clotrimazole group, showed a significant difference two times in the fungal cell count that its average during 48 h was less than 24 h. A significant difference was observed between the two periods in lavender group, only at the dilutions of 1/20 and 1/80. The average fungal cell count after 48 h was also lower in lavender group. Conclusions. Given that the lavender has antifungal activity, this can be used as an antifungal agent. However, more clinical studies are necessary to validate its use in candida infection. PMID:26550521

  7. Antifungal Effect of Lavender Essential Oil (Lavandula angustifolia) and Clotrimazole on Candida albicans: An In Vitro Study.

    PubMed

    Behmanesh, Fereshteh; Pasha, Hajar; Sefidgar, Ali Asghar; Taghizadeh, Mohsen; Moghadamnia, Ali Akbar; Adib Rad, Hajar; Shirkhani, Leyla

    2015-01-01

    Background. The treatment of candidiasis infections is an important problem in the health care system. This study aimed to investigate the in vitro effect of lavender essential oil and clotrimazole on isolated C. albicans from vaginal candidiasis. Materials and Methods. In this clinical trial, C. albicans isolated from the vaginal discharge samples was obtained. Results. The pairwise comparison showed that lavender and clotrimazole had a significant difference; this difference in the lavender group was lower than clotrimazole. But, after 48 hours, there was no difference seen between groups. There was a significant difference between clotrimazole and DMSO groups. Comparing the changes between groups based on the same dilution, at 24 h and 48 h in clotrimazole group, showed a significant difference two times in the fungal cell count that its average during 48 h was less than 24 h. A significant difference was observed between the two periods in lavender group, only at the dilutions of 1/20 and 1/80. The average fungal cell count after 48 h was also lower in lavender group. Conclusions. Given that the lavender has antifungal activity, this can be used as an antifungal agent. However, more clinical studies are necessary to validate its use in candida infection. PMID:26550521

  8. Chloride anion transporters inhibit growth of methicillin-resistant Staphylococcus aureus (MRSA) in vitro.

    PubMed

    Share, Andrew I; Patel, Khushali; Nativi, Cristina; Cho, Eun J; Francesconi, Oscar; Busschaert, Nathalie; Gale, Philip A; Roelens, Stefano; Sessler, Jonathan L

    2016-06-18

    A series of aminopyrrolic receptors were tested as anion transporters using POPC liposome model membranes. Many were found to be effective Cl(-) transporters and to inhibit clinical strains of Staphylococcus aureus growth in vitro. The best transporters proved effective against the methicillin-resistant Staphylococcus aureus (MRSA) strains, Mu50 and HP1173. Tris-thiourea tren-based chloride transporters were also shown to inhibit the growth of S. aureus in vitro. PMID:27223254

  9. Copper, aluminum, iron and calcium inhibit human acetylcholinesterase in vitro.

    PubMed

    Pohanka, Miroslav

    2014-01-01

    Acetylcholinesterase (AChE) is an important part of cholinergic nerves where it participates in termination of neurotransmission. AChE can be inhibited by e.g. some Alzheimer disease drugs, nerve agents, and secondary metabolites. In this work, metal salts aluminum chloride, calcium chloride, cupric chloride, ferric chloride, potassium chloride, magnesium chloride and sodium chloride were tested for their ability to inhibit AChE. Standard Ellman assay based on human recombinant AChE was done and inhibition was measured using Dixon plot. No inhibition was proved for sodium, potassium and magnesium ions. However, aluminum, cupric, ferric and calcium ions were able to inhibit AChE via noncompetitive mechanism of inhibition. Though the inhibition is much weaker when compared to e.g. drugs with noncompetitive mechanism of action, biological relevance of the findings can be anticipated. PMID:24473150

  10. The expression of the β-defensins hBD-2 and hBD-3 is differentially regulated by NF-κB and MAPK/AP-1 pathways in an in vitro model of Candida esophagitis

    PubMed Central

    Steubesand, Nadine; Kiehne, Karlheinz; Brunke, Gabriele; Pahl, Rene; Reiss, Karina; Herzig, Karl-Heinz; Schubert, Sabine; Schreiber, Stefan; Fölsch, Ulrich R; Rosenstiel, Philip; Arlt, Alexander

    2009-01-01

    Background Candida albicans resides on epithelial surfaces as part of the physiological microflora. However, under certain conditions it may cause life-threatening infections like Candida sepsis. Human β-defensins (hBDs) are critical components of host defense at mucosal surfaces and we have recently shown that hBD-2 and hBD-3 are upregulated in Candida esophagitis. We therefore studied the role of Candidate signalling pathways in order to understand the mechanisms involved in regulation of hBD-expression by C. albicans. We used the esophageal cell line OE21 and analysed the role of paracrine signals from polymorphonuclear leukocytes (PMN) in an in vitro model of esophageal candidiasis. Results Supernatants of C. albicans or indirect coculture with C. albicans induces upregulation of hBD-2 and hBD-3 expression. PMNs strongly amplifies C. albicans-mediated induction of hBDs. By EMSA we demonstrate that C. albicans activates NF-κB and AP-1 in OE21 cells. Inhibition of these pathways revealed that hBD-2 expression is synergistically regulated by both NF-κB and AP-1. In contrast hBD-3 expression is independent of NF-κB and relies solely on an EGFR/MAPK/AP-1-dependent pathway. Conclusion Our analysis of signal transduction events demonstrate a functional interaction of epithelial cells with PMNs in response to Candida infection involving divergent signalling events that differentially govern hBD-2 and hBD-3 expression. PMID:19523197

  11. Baicalein Inhibits MCF-7 Cell Proliferation In Vitro, Induces Radiosensitivity, and Inhibits Hypoxia Inducible Factor.

    PubMed

    Gade, Shruti; Gandhi, Nitin Motilal

    2015-01-01

    Hypoxia inducible factor (HIF) is a key transcription factor responsible for imparting adaptability to the cancer cells growing in tumors. HIF induces the modulation of glucose metabolism, angiogenesis, and prosurvival signaling. Therefore, HIF is one of the attractive targets to treat solid tumors. Results presented in this study indicate that Baicalein (BA) inhibits HIF stabilization and also reduces its transcription activity in MCF-7 cells in vitro. Furthermore, BA was found to have antiproliferative ability as determined by the MTT assay and clonogenic survival. BA also induces apoptosis in MCF-7 cells at the concentration of 50 µM. We also report the radiosensitization of MCF-7 cells when they are treated with BA, resulting in higher γ-radiation-induced DNA damage. BA is extensively used in Chinese medicine and is known to be nontoxic at pharmacological doses. Our studies indicate that BA is one of the attractive natural compounds suitable for further evaluation as an adjuvant therapy. PMID:26756423

  12. Iron Inhibits Respiratory Burst of Peritoneal Phagocytes In Vitro

    PubMed Central

    Gotfryd, Kamil; Jurek, Aleksandra; Kubit, Piotr; Klein, Andrzej; Turyna, Bohdan

    2011-01-01

    Objective. This study examines the effects of iron ions Fe3+ on the respiratory burst of phagocytes isolated from peritoneal effluents of continuous ambulatory peritoneal dialysis (CAPD) patients, as an in vitro model of iron overload in end-stage renal disease (ESRD). Material and Methods. Respiratory burst of peritoneal phagocytes was measured by chemiluminescence method. Results. At the highest used concentration of iron ions Fe3+ (100 μM), free radicals production by peritoneal phagocytes was reduced by 90% compared to control. Conclusions. Iron overload may increase the risk of infectious complications in ESRD patients. PMID:22203913

  13. Small molecules inhibit growth, viability and ergosterol biosynthesis in Candida albicans.

    PubMed

    Rajput, Sandeep B; Karuppayil, S Mohan

    2013-12-01

    The aim of this work was to evaluate the anti-Candida efficacy of twenty five molecules of plant origin. Based on their MICs, effective molecules were categorized into four categories. Susceptibility testing of test compounds was carried out by standard methodology (M27-A2) as per CLSI guidelines. Minimum Fungicidal Concentration (MFC) was determined as the lowest concentration of drug killing 99.9% cells. Effect on sterol profile was evaluated by sterol quantitation method. Among the screened molecules, cinnamaldehyde, piperidine, citral, furfuraldehyde and indole were potent inhibitors of growth and viability. Exposure of Candida cells to cinnamaldehyde, piperidine, citral, furfuraldehyde, indole, α- and β- pinene at MIC's, altered ergosterol profile. Our results indicate that the molecules altering sterol profile may exert their antifungal effect through inhibition of ergosterol biosynthesis and could be good candidates for fungal specific drug development. PMID:23449869

  14. In vitro Effects of Lemongrass Extract on Candida albicans Biofilms, Human Cells Viability, and Denture Surface

    PubMed Central

    Madeira, Petrus L. B.; Carvalho, Letícia T.; Paschoal, Marco A. B.; de Sousa, Eduardo M.; Moffa, Eduardo B.; da Silva, Marcos A. dos Santos; Tavarez, Rudys de Jesus Rodolfo; Gonçalves, Letícia M.

    2016-01-01

    The purpose of this study was to investigate whether immersion of a denture surface in lemongrass extract (LGE) has effects on C. albicans biofilms, human cell viability and denture surface. Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) were performed for LGE against C. albicans. For biofilm analysis, discs were fabricated using a denture acrylic resin with surface roughness standardization. C. albicans biofilms were developed on saliva-coated discs, and the effects of LGE at MIC, 5XMIC, and 10XMIC were investigated during biofilm formation and after biofilm maturation. Biofilms were investigated for cell counting, metabolic activity, and microscopic analysis. The cytotoxicity of different concentrations of LGE to peripheral blood mononuclear cells (PBMC) was analyzed using MTT. The effects of LGE on acrylic resin were verified by measuring changes in roughness, color and flexural strength after 28 days of immersion. Data were analyzed by ANOVA, followed by a Tukey test at a 5% significance level. The minimal concentration of LGE required to inhibit C. albicans growth was 0.625 mg/mL, while MFC was 2.5 mg/mL. The presence of LGE during biofilm development resulted in a reduction of cell counting (p < 0.05), which made the MIC sufficient to reduce approximately 90% of cells (p < 0.0001). The exposure of LGE after biofilm maturation also had a significant antifungal effect at all concentrations (p < 0.05). When compared to the control group, the exposure of PBMC to LGE at MIC resulted in similar viability (p > 0.05). There were no verified differences in color perception, roughness, or flexural strength after immersion in LGE at MIC compared to the control (p > 0.05). It could be concluded that immersion of the denture surface in LGE was effective in reducing C. albicans biofilms with no deleterious effects on acrylic properties at MIC. MIC was also an effective and safe concentration for use. PMID:27446818

  15. In vitro Effects of Lemongrass Extract on Candida albicans Biofilms, Human Cells Viability, and Denture Surface.

    PubMed

    Madeira, Petrus L B; Carvalho, Letícia T; Paschoal, Marco A B; de Sousa, Eduardo M; Moffa, Eduardo B; da Silva, Marcos A Dos Santos; Tavarez, Rudys de Jesus Rodolfo; Gonçalves, Letícia M

    2016-01-01

    The purpose of this study was to investigate whether immersion of a denture surface in lemongrass extract (LGE) has effects on C. albicans biofilms, human cell viability and denture surface. Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) were performed for LGE against C. albicans. For biofilm analysis, discs were fabricated using a denture acrylic resin with surface roughness standardization. C. albicans biofilms were developed on saliva-coated discs, and the effects of LGE at MIC, 5XMIC, and 10XMIC were investigated during biofilm formation and after biofilm maturation. Biofilms were investigated for cell counting, metabolic activity, and microscopic analysis. The cytotoxicity of different concentrations of LGE to peripheral blood mononuclear cells (PBMC) was analyzed using MTT. The effects of LGE on acrylic resin were verified by measuring changes in roughness, color and flexural strength after 28 days of immersion. Data were analyzed by ANOVA, followed by a Tukey test at a 5% significance level. The minimal concentration of LGE required to inhibit C. albicans growth was 0.625 mg/mL, while MFC was 2.5 mg/mL. The presence of LGE during biofilm development resulted in a reduction of cell counting (p < 0.05), which made the MIC sufficient to reduce approximately 90% of cells (p < 0.0001). The exposure of LGE after biofilm maturation also had a significant antifungal effect at all concentrations (p < 0.05). When compared to the control group, the exposure of PBMC to LGE at MIC resulted in similar viability (p > 0.05). There were no verified differences in color perception, roughness, or flexural strength after immersion in LGE at MIC compared to the control (p > 0.05). It could be concluded that immersion of the denture surface in LGE was effective in reducing C. albicans biofilms with no deleterious effects on acrylic properties at MIC. MIC was also an effective and safe concentration for use. PMID:27446818

  16. Inhibition of human natural killer (NK) cytotoxicity by Candida albicans

    SciTech Connect

    Zunino, S.; Hudig, D.

    1986-03-01

    Experiments were initiated to determine whether human NK cells are cytotoxic to C. albicans with similar activity observed for mouse NK cells against the yeast Paracoccidiodes brasiliensis. In 48 hour assays using limiting dilutions of C. albicans, strain 3153A, mononuclear leukocytes with NK activity had only marginal effects on yeast outgrowth, whereas granulocytes killed most of the yeast. However, these yeast were able to block NK activity in 4 hr /sup 51/Cr release assays with K562 cells, at yeast to K562 ratios of 10:1 and 100:1. Yeast pretreated with the serum of the majority of donors blocked the NK activity more than untreated yeast. Two of the 7 donors did not enhance NK inhibition after pretreatment of the yeast with their serum. Serum antibody to C. albicans and complement consumption by the yeast correlated with the relative efficiency of NK inhibition for most donors. This report suggests that there may be in vivo interactions between NK cells of the immune system and opportunistic fungal pathogens, which may compromise NK cell function.

  17. Vitamin D inhibition of lung adenocarcinoma cell proliferation in vitro.

    PubMed

    Li, Rong; Lou, Yuqing; Zhang, Weiyan; Dong, Qianggang; Han, Baohui

    2014-11-01

    Vitamin D has the capability to inhibit tumor cell proliferation and promote tumor cell apoptosis but whether this mechanism exists in lung adenocarcinoma cells remains to be studied. Our objective is to explore whether vitamin D has the capability to inhibit lung adenocarcinoma cell proliferation and synergize with cisplatin. Our method was to explore the effect of different concentrations of 1,25(OH)2D3 with or without cisplatin on lung adenocarcinoma cells by detecting cell proliferation rates at different time points. 1,25(OH)2D3 was capsulated with nanomaterial before acting on lung adenocarcinoma cells, and cell proliferation rates at different time points were detected with the CCK-8 method. When vitamin D was applied at a concentration of 1 × 10(-7) and 1 × 10(-6) mol/L on A549, PC9, SPC-A1, and H1650 cells for 72 h, no inhibition occurred on cell proliferation. Between the concentrations of 1 × 10(-5) and 0.5 × 10(-5) mol/L, inhibition on cell proliferation increased with drug action time. Between the concentration of 2.5 × 10(-5) and 0.03 × 10(-5) mol/L, inhibition on cell proliferation increased with increasing drug concentration. Analysis using bivariate correlations showed that the correlation coefficient of the proliferation inhibition rate and drug content was 0.580 (p < 0.0001). The correlation coefficient of proliferation inhibition rate and the drug action time was 0.379 (p = 0.01). The combined use of vitamin D and dichlorodiammine-platinum(II) (DDP) significantly increased the inhibition rate on A549 cell proliferation, which peaked after culturing for 96 h (Table 4). Further analysis using bivariate correlations showed that the correlation coefficient between proliferation inhibition rate and DDP concentration was 0.319 (p < 0.0001). The correlation coefficient of the proliferation inhibition rate and vitamin D concentration was 0.269 (p < 0.0001). The correlation coefficient of proliferation inhibition and drug action time was 0.221(p

  18. Supramolecular nanofibrils inhibit cancer progression in vitro and in vivo

    PubMed Central

    Kuang, Yi; Du, Xuewen; Zhou, Jie; Xu, Bing

    2014-01-01

    The recent discovery of the inverse comorbidity between cancer and Alzheimer’s disease implies that one may use amyloids to inhibit tumors. During the conversion of a dipeptide segment (Phe-Phe) in β-amyloid into a supramolecular hydrogelator, we obtained a small molecule (1) that can self-assembly into nanofibrils via multiple intermolecular hydrogen bonding and aromatic-aromatic interactions. Interestingly, while the monomers of 1 are innocuous, the nanofibrils formed by 1 can selectively inhibit the growth of glioblastoma cells over neuronal cells. To further assess the potential of this small molecular nanofibrils as anti-cancer agent, we exam the biological activity of the nanofibrils and demonstrate that the nanofibrils of 1 efficiently inhibit the progression of cancer cells (e.g., HeLa cells) both in cell assays and on xenograft mice model. This work suggests that nanofibrils derived from core motif of amyloid are effective agents for inhibiting cancer progression. Thus, this work contributes to a new approach that uses supramolecular nanofibrils as de novo molecular amyloids for inhibiting the growth of cancer cells. PMID:24574174

  19. In vitro activity of Cinnamomum zeylanicum against azole resistant and sensitive Candida species and a pilot study of cinnamon for oral candidiasis.

    PubMed

    Quale, J M; Landman, D; Zaman, M M; Burney, S; Sathe, S S

    1996-01-01

    Fluconazole-resistant Candida species are an emerging problem. In this report, the in vitro activity of C. zeylanicum against fluconazole-resistant and-susceptible Candida isolates is described. The MICs of the bark of C. zeylanicum ranged from < 0.05-30 mg/ml, and were slightly better than commercially available cinnamon powder. Trans-cinnamaldehyde and O-methoxycinnamaldehyde had MICs of 0.03-0.5 mg/ml. The MICs of selected cinnamon candies and gums generally ranged from 25-100 mg/ml. Five patients with HIV infection and oral candidiasis received a commercially available cinnamon preparation for one week. There of the five patients had improvement of their oral candidiasis. Clinical trials will be necessary to determine the usefulness of cinnamon for the treatment of mucosal candidiasis. PMID:8874667

  20. Thalassemic erythrocytes inhibit in vitro growth of Plasmodium falciparum.

    PubMed Central

    Brockelman, C R; Wongsattayanont, B; Tan-ariya, P; Fucharoen, S

    1987-01-01

    Blood specimens from 100 thalassemic patients were screened in vitro for inhibitory effects on growth and multiplication of Plasmodium falciparum. The culture medium mixture designated REM consisted of 9 volumes of minimum essential medium (GIBCO Laboratories, Grand Island, N.Y.) and 1 volume of RPMI 1640 (GIBCO) supplemented with 10% heat-inactivated human serum. Parasite multiplication in erythrocytes containing normal hemoglobin cultured in RPMI or REM was similar. Significant reduction in parasite multiplication rates was observed in erythrocytes containing abnormal hemoglobin when these were cultured in REM. The degree of reduction in five types of thalassemic erythrocytes was in the following descending order: hemoglobin H disease with Hb Constant Spring, classical hemoglobin H disease, beta(0)-thalassemia-hemoglobin E in which blood harbored a high percentage of hemoglobin F-containing cells, beta (0)-thalassemia-hemoglobin E in which blood harbored few hemoglobin F-containing cells, and beta-thalassemia heterozygous variant. PMID:3539999

  1. Nesfatin-1 inhibits ovarian epithelial carcinoma cell proliferation in vitro

    SciTech Connect

    Xu, Yang; Pang, Xiaoyan; Dong, Mei; Wen, Fang Zhang, Yi

    2013-11-01

    Highlights: •Nesfatin-1 inhibits the proliferation and growth of HO-8910 cells by G1 phase arrest. •Nesfatin-1 enhances HO-8910 cell apoptosis. •Nesfatin-1 inhibits HO-8910 cell proliferation via mTOR and RhoA/ROCK signaling pathway. •The first report of nesfatin-1-mediated proliferation in ovarian epithelial carcinoma. -- Abstract: Nesfatin-1, an 82-amino-acid peptide derived from a 396-amino-acid precursor protein nucleobindin 2 (NUCB2), was originally identified in hypothalamic nuclei involved in the regulation of food intake. It was recently reported that nesfatin-1 is a novel depot specific adipokine preferentially produced by subcutaneous tissue, with obesity- and food deprivation-regulated expression. Although a relation between ovarian cancer mortality and obesity has been previously established, a role of nesfatin-1 in ovarian epithelial carcinoma remains unknown. The aim of the present study is to examine the effect of nesfatin-1 on ovary carcinoma cells proliferation. We found that nesfatin-1 inhibits the proliferation and growth of HO-8910 cells by G1 phase arrest, this inhibition could be abolished by nesfatin-1 neutralizing antibody. Nesfatin-1 enhances HO-8910 cell apoptosis, activation of mammalian target of rapamycin (mTOR) and RhoA/ROCK signaling pathway block the effects of nesfatin-1-induced apoptosis, therefore reverses the inhibition of HO-8910 cell proliferation by nesfatin-1. In conclusion, the present study demonstrated that nesfatin-1 can inhibit the proliferation in human ovarian epithelial carcinoma cell line HO-8910 cells through inducing apoptosis via mTOR and RhoA/ROCK signaling pathway. This study provides a novel regulatory signaling pathway of nesfatin-1-regulated ovarian epithelial carcinoma growth and may contribute to ovarian cancer prevention and therapy, especially in obese patients.

  2. Inhibition of Plasmodium falciparum dihydropteroate synthetase and growth in vitro by sulfa drugs.

    PubMed Central

    Zhang, Y; Meshnick, S R

    1991-01-01

    The Michaelis-Menten inhibitory constants (Kis) and the concentrations required for 50% inhibition of the Plasmodium falciparum dihydropteroate synthetase were determined for six sulfa drugs. These drugs inhibited the in vitro growth of P. falciparum (50% lethal concentration) at concentrations of 30 to 500 nM; these concentrations were 100 to 1,000 times lower than the concentrations required for 50% inhibition and Kis (6 to 500 microM). The uptake of p-aminobenzoic acid was not inhibited by the sulfa drugs. However, infected erythrocytes took up more labeled sulfamethoxazole than did uninfected erythrocytes. Thus, the concentration of sulfa drugs by malaria parasites may explain how sulfa drugs inhibit in vitro growth of parasites through the inhibition of dihydropteroate synthetase. PMID:2024960

  3. The FGF-2-Derived Peptide FREG Inhibits Melanoma Growth In Vitro and In Vivo

    PubMed Central

    Aguzzi, Maria S; Faraone, Debora; D'Arcangelo, Daniela; De Marchis, Francesco; Toietta, Gabriele; Ribatti, Domenico; Parazzoli, Alberto; Colombo, Paolo; Capogrossi, Maurizio C; Facchiano, Antonio

    2011-01-01

    Previous data report that fibroblast growth factor-2 (FGF-2)-derived peptide FREG potently inhibits FGF-2-dependent angiogenesis in vitro and in vivo. Here, we show that FREG inhibits up to 70% in vitro growth and invasion/migration of smooth muscle and melanoma cells. Such inhibition is mediated by platelet-derived growth factor-receptor-α (PDGF-Rα); in fact, proliferation and migration were restored upon PDGF-Rα neutralization. Further experiments demonstrated that FREG interacts with PDGF-Rα both in vitro and in vivo and stimulates its phosphorylation. We have previously shown that overexpressing PDGF-Rα strongly inhibits melanoma growth in vivo; we, therefore, hypothesized that PDGF-Rα agonists may represent a novel tool to inhibit melanoma growth in vivo. To support this hypothesis, FREG was inoculated intravenously (i.v.) in a mouse melanoma model and markedly inhibited pulmonary metastases formation. Immunohistochemical analyses showed less proliferation, less angiogenesis, and more apoptosis in metastasized lungs upon FREG treatment, as compared to untreated controls. Finally, in preliminary acute toxicity studies, FREG showed no toxicity signs in healthy animals, and neither microscopic nor macroscopic toxicity at the liver, kidney, and lungs level. Altogether, these data indicate that FREG systemic treatment strongly inhibits melanoma metastases development and indicate for the first time that agonists of PDGF-Rα may control melanoma both in vitro and in vivo. PMID:20924364

  4. Inhibition of catalase activity in vitro by diesel exhaust particles

    SciTech Connect

    Mori, Yoki; Murakami, Sumika; Sagae, Toshiyuki

    1996-02-09

    The effect of diesel exhaust particles (DEP) on the activity of catalase, an intracellular anti-oxidant, was investigated because H{sub 2}O{sub 2} is a cytotoxic oxidant, and catalase released from alveolar cells is an important antioxidant in the epithelial lining fluid in the lung. DEP inhibited the activity of bovine liver catalase dose-dependently, to 25-30% of its original value. The inhibition of catalase by DEP was observed only in the presence of anions such as Cl{sup {minus}}, Br{sup {minus}}, or thiocyanate. Other anions, such as CH{sub 3}COO{sup {minus}} or SO{sub 4}{sup {minus}}, and cations such as K{sup +}, Na{sup +}, Mg{sup 2+}, or Fe{sup 2+}, did not affect the activity of catalase, even in the presence of DEP extract. Catalase from guinea pig alveolar cells and catalase from red blood cells were also inhibited by DEP extracts, as was catalase from bovine liver. These results suggest that DEP taken up in the lung and located on alveolar spaces might cause cell injury by inhibiting the activity of catalase in epithelial lining fluid, enhancing the toxicity of H{sub 2}O{sub 2} generated from cells in addition to that of O{sub 2}{sup {minus}} generated by the chemical reaction of DEP with oxygen. 10 refs., 6 figs.

  5. Correlation between In Vitro and In Vivo Activities of GM 237354, a New Sordarin Derivative, against Candida albicans in an In Vitro Pharmacokinetic-Pharmacodynamic Model and Influence of Protein Binding

    PubMed Central

    Aviles, P.; Falcoz, C.; Guillén, M. J.; San Roman, R.; Gómez De Las Heras, F.; Gargallo-Viola, D.

    2001-01-01

    The antifungal effect of GM 237354, a sordarin derivative, was studied in an in vitro pharmacokinetic (PK)-pharmacodynamic dynamic system (bioreactor) which reproduces PK profiles observed in a previously described model of drug efficacy against murine systemic candidiasis. Immunocompetent mice infected intravenously with 105 CFU of Candida albicans were treated with GM 237354 at 2.5, 10, and 40 mg/kg of body weight every 8 h subcutaneously for 7 days. Free concentrations in serum were calculated by multiplying total concentrations measured in vivo by 0.05, the free fraction determined in vitro by equilibrium dialysis. In the bioreactor the inoculum was ≈106 CFU/ml; and a one-compartment PK model was used to reproduce the PK profiles of free and total GM 237354 in serum obtained in mice, and clearance of C. albicans was measured over 48 h. A good correlation was observed when the in vivo fungal kidney burden and the area under the survival time curve were compared with the in vitro broth “burden,” although only when free in vivo levels in serum were reproduced in vitro. GM 237354 displayed a 3-log decrease effect both in vivo and in vitro. The very few reports available on in vitro-in vivo correlations have been obtained with antibiotics. The good in vitro-in vivo correlation obtained with an antifungal agent shows that the in vitro dynamic system could constitute a powerful investigational tool prior to assessment of the efficacy of an anti-infective agent in animals and humans. PMID:11557464

  6. DNase inhibits Gardnerella vaginalis biofilms in vitro and in vivo.

    PubMed

    Hymes, Saul R; Randis, Tara M; Sun, Thomas Yang; Ratner, Adam J

    2013-05-15

    Bacterial vaginosis is a highly prevalent and poorly understood polymicrobial disorder of the vaginal microbiota, with significant adverse sequelae. Gardnerella vaginalis predominates in bacterial vaginosis. Biofilms of G. vaginalis are present in human infections and are implicated in persistent disease, treatment failure, and transmission. Here we demonstrate that G. vaginalis biofilms contain extracellular DNA, which is essential to their structural integrity. Enzymatic disruption of this DNA specifically inhibits biofilms, acting on both newly forming and established biofilms. DNase liberates bacteria from the biofilm to supernatant fractions and potentiates the activity of metronidazole, an antimicrobial agent used in the treatment of bacterial vaginosis. Using a new murine vaginal colonization model for G. vaginalis, we demonstrate >10-fold inhibition of G. vaginalis colonization by DNase. We conclude that DNase merits investigation as a potential nonantibiotic adjunct to existing bacterial vaginosis therapies in order to decrease the risk of chronic infection, recurrence, and associated morbidities. PMID:23431033

  7. Inhibition of leucocytic lysosomal enzymes by glycosaminoglycans in vitro.

    PubMed Central

    Avila, J L; Convit, J

    1975-01-01

    1. A lysosomal fraction was separated by density-gradient centrifugation from a highly purified human polymorphonuclear leucocyte suspension. 2. Some 23 different lysosomal enzymes were assayed for activity in the presence of various concentrations of glycosaminoglycans. 3. The 21 acid hydrolases assayed were strongly inhibited to different degrees by low (0-12 mmol/l) concentrations of glycosaminoglycans in a pH-dependent manner. Thus inhibitions were stronger below pH4.5, with activity returning to control values at about pH5.0. 4. On a molar basis, the inhibitory activity for the several glycosaminoglycans studied was: heparin greater than chondroitin sulphate greater than hyaluronic acid. 5. Once the glycosaminoglycan-acid hydrolase complex was formed, it was partially dissociated by slight elevations in the pH of the incubation medium, by increasing the ionic strength of the incubation medium, or by adding several cationic proteins (e.g. histone, protamine). 6. As leucocytic lysosomes contain large amounts of chondroitin sulphate, and have a strongly acid intragranular pH, we suggest that glycosaminoglycans may modify lysosomal function through the formation of complexes with lysosomal enzymes, by inhibiting the digestive activity of the acid hydrolases when the intralysosomal pH is below their pI. PMID:2162

  8. Inhibition of Candida albicans biofilm formation and modulation of gene expression by probiotic cells and supernatant.

    PubMed

    James, K M; MacDonald, K W; Chanyi, R M; Cadieux, P A; Burton, J P

    2016-04-01

    Oral candidiasis is a disease caused by opportunistic species of Candida that normally reside on human mucosal surfaces. The transition of Candida from budding yeast to filamentous hyphae allows for covalent attachment to oral epithelial cells, followed by biofilm formation, invasion and tissue damage. In this study, combinations of Lactobacillus plantarum SD5870, Lactobacillus helveticus CBS N116411 and Streptococcus salivarius DSM 14685 were assessed for their ability to inhibit the formation of and disrupt Candida albicans biofilms. Co-incubation with probiotic supernatants under hyphae-inducing conditions reduced C. albicans biofilm formation by >75 % in all treatment groups. Likewise, combinations of live probiotics reduced biofilm formation of C. albicans by >67 %. When live probiotics or their supernatants were overlaid on preformed C. albicans biofilms, biofilm size was reduced by >63 and >65 % respectively. Quantitative real-time PCR results indicated that the combined supernatants of SD5870 and CBS N116411 significantly reduced the expression of several C. albicans genes involved in the yeast-hyphae transition: ALS3 (adhesin/invasin) by 70 % (P < 0.0001), EFG1 (hyphae-specific gene activator) by 47 % (P = 0.0061), SAP5 (secreted protease) by 49 % (P < 0.0001) and HWP1 (hyphal wall protein critical to biofilm formation) by >99 % (P < 0.0001). These findings suggest the combination of L. plantarum SD5870, L. helveticus CBS N116411 and S. salivarius DSM 14685 is effective at both preventing the formation of and removing preformed C. albicans biofilms. Our novel results point to the downregulation of several Candida genes critical to the yeast-hyphae transition, biofilm formation, tissue invasion and cellular damage. PMID:26847045

  9. In vitro growth inhibition of mastitis pathogens by bovine teat skin normal flora.

    PubMed Central

    Woodward, W D; Besser, T E; Ward, A C; Corbeil, L B

    1987-01-01

    One factor contributing to differences in the susceptibility of cows to mastitis may be differences in the teat skin normal flora, which could inhibit or enhance the growth of pathogenic bacteria. Using in vitro cross-streaking methods, we found that 25% of the isolates of teat normal flora of non-lactating heifers inhibited the growth of selected mastitis pathogens, but enhancers were not detected. Gram-positive pathogens were inhibited to a greater extent than Gram-negative pathogens. Inhibition was not a characteristic of specific genera or species of normal flora, but rather a property of certain variants within a species. This phenomenon of inhibition of mastitis pathogens in vitro by normal flora may be useful as an in vivo biological control method to reduce the incidence of mastitis. PMID:3552170

  10. Gellan sulfate inhibits Plasmodium falciparum growth and invasion of red blood cells in vitro

    PubMed Central

    Recuenco, Frances Cagayat; Kobayashi, Kyousuke; Ishiwa, Akiko; Enomoto-Rogers, Yukiko; Fundador, Noreen Grace V.; Sugi, Tatsuki; Takemae, Hitoshi; Iwanaga, Tatsuya; Murakoshi, Fumi; Gong, Haiyan; Inomata, Atsuko; Horimoto, Taisuke; Iwata, Tadahisa; Kato, Kentaro

    2014-01-01

    Here, we assessed the sulfated derivative of the microbial polysaccharide gellan gum and derivatives of λ and κ-carrageenans for their ability to inhibit Plasmodium falciparum 3D7 and Dd2 growth and invasion of red blood cells in vitro. Growth inhibition was assessed by means of flow cytometry after a 96-h exposure to the inhibitors and invasion inhibition was assessed by counting ring parasites after a 20-h exposure to them. Gellan sulfate strongly inhibited invasion and modestly inhibited growth for both P. falciparum 3D7 and Dd2; both inhibitory effects exceeded those achieved with native gellan gum. The hydrolyzed λ-carrageenan and oversulfated κ-carrageenan were less inhibitory than their native forms. In vitro cytotoxicity and anticoagulation assays performed to determine the suitability of the modified polysaccharides for in vivo studies showed that our synthesized gellan sulfate had low cytotoxicity and anticoagulant activity. PMID:24740150

  11. Gellan sulfate inhibits Plasmodium falciparum growth and invasion of red blood cells in vitro.

    PubMed

    Recuenco, Frances Cagayat; Kobayashi, Kyousuke; Ishiwa, Akiko; Enomoto-Rogers, Yukiko; Fundador, Noreen Grace V; Sugi, Tatsuki; Takemae, Hitoshi; Iwanaga, Tatsuya; Murakoshi, Fumi; Gong, Haiyan; Inomata, Atsuko; Horimoto, Taisuke; Iwata, Tadahisa; Kato, Kentaro

    2014-01-01

    Here, we assessed the sulfated derivative of the microbial polysaccharide gellan gum and derivatives of λ and κ-carrageenans for their ability to inhibit Plasmodium falciparum 3D7 and Dd2 growth and invasion of red blood cells in vitro. Growth inhibition was assessed by means of flow cytometry after a 96-h exposure to the inhibitors and invasion inhibition was assessed by counting ring parasites after a 20-h exposure to them. Gellan sulfate strongly inhibited invasion and modestly inhibited growth for both P. falciparum 3D7 and Dd2; both inhibitory effects exceeded those achieved with native gellan gum. The hydrolyzed λ-carrageenan and oversulfated κ-carrageenan were less inhibitory than their native forms. In vitro cytotoxicity and anticoagulation assays performed to determine the suitability of the modified polysaccharides for in vivo studies showed that our synthesized gellan sulfate had low cytotoxicity and anticoagulant activity. PMID:24740150

  12. Serotypes of Plasmodium falciparum defined by immune serum inhibition of in vitro growth*

    PubMed Central

    Chulay, J. D.; Haynes, J. D.; Diggs, C. L.

    1985-01-01

    In vitro growth inhibition assays were used to detect antigenic differences among geographically distinct strains of Plasmodium falciparum. Owl monkeys were immunized against the Camp and FCR-3/FMG strains of P. falciparum by infection, drug treatment, and rechallenge with homologous parasites. Camp-immune monkey serum was used to inhibit the in vitro growth of eight strains of P. falciparum. Inhibition was maximum for the homologous Camp strain (an average of 62% inhibition by 100 ml/litre Camp-immune serum). Four other strains were inhibited to a lesser degree, and three strains (FCR-3/FMG, FVO, and Smith) were not significantly inhibited by Camp-immune serum at concentrations as high as 400 ml/litre. FCR-3/FMG-immune serum at a concentration of 50 ml/litre caused significant inhibition of the FCR-3/FMG strain, but not the Camp strain. Thus Camp and FCR-3/FMG strains appear to bear distinct antigenic determinants recognized by the homologous, but not the heterologous, antiserum. Inhibition of in vitro growth by immune serum may be useful for serotyping P. falciparum and may have application in the selection of strains for inclusion in a malaria vaccine. PMID:3893775

  13. An Optimized Lock Solution Containing Micafungin, Ethanol and Doxycycline Inhibits Candida albicans and Mixed C. albicans – Staphyloccoccus aureus Biofilms

    PubMed Central

    Lown, Livia; Peters, Brian M.; Walraven, Carla J.; Noverr, Mairi C.; Lee, Samuel A.

    2016-01-01

    Candida albicans is a major cause of catheter-related bloodstream infections and is associated with high morbidity and mortality. Due to the propensity of C. albicans to form drug-resistant biofilms, the current standard of care includes catheter removal; however, reinsertion may be technically challenging or risky. Prolonged exposure of an antifungal lock solution within the catheter in conjunction with systemic therapy has been experimentally attempted for catheter salvage. Previously, we demonstrated excellent in vitro activity of micafungin, ethanol, and high-dose doxycycline as single agents for prevention and treatment of C. albicans biofilms. Thus, we sought to investigate optimal combinations of micafungin, ethanol, and/or doxycycline as a lock solution. We performed two- and three-drug checkerboard assays to determine the in vitro activity of pairwise or three agents in combination for prevention or treatment of C. albicans biofilms. Optimal lock solutions were tested for activity against C. albicans clinical isolates, reference strains and polymicrobial C. albicans-S. aureus biofilms. A solution containing 20% (v/v) ethanol, 0.01565 μg/mL micafungin, and 800 μg/mL doxycycline demonstrated a reduction of 98% metabolic activity and no fungal regrowth when used to prevent fungal biofilm formation; however there was no advantage over 20% ethanol alone. This solution was also successful in inhibiting the regrowth of C. albicans from mature polymicrobial biofilms, although it was not fully bactericidal. Solutions containing 5% ethanol with low concentrations of micafungin and doxycycline demonstrated synergistic activity when used to prevent monomicrobial C. albicans biofilm formation. A combined solution of micafungin, ethanol and doxycycline is highly effective for the prevention of C. albicans biofilm formation but did not demonstrate an advantage over 20% ethanol alone in these studies. PMID:27428310

  14. Inhibition of peptidoglycan hydrolase activity in vivo and in vitro by energy uncouplers in Escherichia coli.

    PubMed

    Rodionov, D G; Ishiguro, E E

    1996-01-01

    The effects of energy uncouplers on in vivo and in vitro peptidoglycan hydrolase activities in Escherichia coli were determined. Sodium azide, potassium cyanide, and carbonyl cyanide m-chlorophenylhydrazone all inhibited ampicillin-induced lysis of exponential phase cultures, even when they were added to lysis-committed cultures. These energy uncouplers also inhibited the solubilization of radiolabeled peptidoglycan by bacterial suspensions that had been treated with 5% trichloroacetic acid by the method of Hartmann et al.3 to activate the peptidoglycan hydrolases. Therefore, the in vivo and in vitro activities of peptidoglycan hydrolases in E. coli are dependent on membrane energization. PMID:9158735

  15. Piperlongumine inhibits proliferation and survival of Burkitt lymphoma in vitro

    PubMed Central

    Han, Seong-Su; Son, Dong-Ju; Yun, Hwakyung; Kamberos, Natalie L.; Janz, Siegfried

    2013-01-01

    Piperlongumine (PL), a pepper plant alkaloid from Piper longum, kills solid tumor cells in a highly selective, potent fashion. To evaluate whether PL may have similar effects on malignant blood cells, we determined the efficacy with which PL inhibits the B-lymphocyte derived neoplasm, Burkitt lymphoma (BL). Low micromolar concentrations of PL (IC50 = 2.8 × 8.5 μM) curbed growth and survival of two EBV+ BL cell lines (Daudi, Raji) and two EBV− BL cell lines (Ramos, DG-75), but left normal peripheral blood B-lymphocytes unharmed. PL-dependent cytotoxicity was effected in part by reduced NF-κB and MYC activity, with the former being caused by inhibition of IκBα degradation, nuclear translocation of p65, and binding of NF-κB dimers to cognate DNA sequences in gene promoters. In 4 of 4 BL cell lines, the NF-κB/MYC-regulated cellular target genes, E2F1 and MYB, were down regulated, while the stress sensor gene, GADD45B, was up regulated. The EBV-encoded oncogene, LMP-1, was suppressed in Daudi and Raji cells. Considering that NF-κB, MYC and LMP-1 play a crucial role in the biology of many blood cancers including BL, our results provide a strong preclinical rationale for considering PL in new intervention approaches for patients with hematologic malignancies. PMID:23237561

  16. Caffeine inhibits hepatitis C virus replication in vitro.

    PubMed

    Batista, Mariana N; Carneiro, Bruno M; Braga, Ana Cláudia S; Rahal, Paula

    2015-02-01

    Hepatitis C is considered the major cause of cirrhosis and hepatocellular carcinoma. Conventional treatment is not effective against some hepatitis C virus (HCV) genotypes; therefore, new treatments are needed. Coffee and, more recently, caffeine, have been found to have a beneficial effect in several disorders of the liver, including those manifesting abnormal liver biochemistry, cirrhosis and hepatocellular carcinoma. Caffeine acts directly by delaying fibrosis, thereby improving the function of liver cellular pathways and interfering with pathways used by the HCV replication cycle. In the current study, the direct relationship between caffeine and viral replication was evaluated. The Huh-7.5 cell line was used for transient infections with FL-J6/JFH-5'C19Rluc2AUbi and to establish a cell line stably expressing SGR-Feo JFH-1. Caffeine efficiently inhibited HCV replication in a dose-dependent manner at non-cytotoxic concentrations and demonstrated an IC50 value of 0.7263 mM after 48 h of incubation. These data demonstrate that caffeine may be an important new agent for anti-HCV therapies due to its efficient inhibition of HCV replication at non-toxic concentrations. PMID:25491197

  17. In vitro inhibition of struvite crystal growth by acetohydroxamic acid.

    PubMed

    Downey, J A; Nickel, J C; Clapham, L; McLean, R J

    1992-10-01

    Struvite (MgNH4PO46H2O) crystals were produced by Proteus mirabilis growth in artificial urine, in the presence and absence of the urease inhibitor, acetohydroxamic acid (AHA). In the absence of AHA, struvite crystals assumed an "X-shaped" or dendritic crystal habit due to rapid growth along their 100 axis. When AHA was present, crystal growth, as monitored by phase contrast light microscopy, was greatly slowed, and the crystals assumed an octahedral crystal habit. Scanning electron microscopy revealed that crystals grown in the presence of AHA were pitted on their surface. This pitting was absent in control samples. While most of this inhibition by AHA was due to lowered urease activity, some crystal growth inhibition occurred in struvite produced in the absence of urease activity through NH4OH titration of artificial urine. We conclude that while AHA is primarily a urease inhibitor, it may also disrupt struvite growth and formation directly through interference with the molecular growth processes on crystal surfaces. PMID:1450840

  18. Strontium promotes cementoblasts differentiation through inhibiting sclerostin expression in vitro.

    PubMed

    Bao, Xingfu; Liu, Xianjun; Zhang, Yi; Cui, Yue; Yao, Jindan; Hu, Min

    2014-01-01

    Cementogenesis, performed by cementoblasts, is important for the repair of root resorption caused by orthodontic treatment. Based on recent studies, strontium has been applied for osteoporosis treatment due to its positive effect on osteoblasts. Although promising, the effect of strontium on cementoblasts is still unclear. So the aim of this research was to clarify and investigate the effect of strontium on cementogenesis via employing cementoblasts as model. A series of experiments including MTT, alkaline phosphatase activity, gene analysis, alizarin red staining, and western blot were carried out to evaluate the proliferation and differentiation of cementoblasts. In addition, expression of sclerostin was checked to analyze the possible mechanism. Our results show that strontium inhibits the proliferation of cementoblasts with a dose dependent manner; however, it can promote the differentiation of cementoblasts via downregulating sclerostin expression. Taking together, strontium may facilitate cementogenesis and benefit the treatment of root resorption at a low dose. PMID:25003114

  19. Strontium Promotes Cementoblasts Differentiation through Inhibiting Sclerostin Expression In Vitro

    PubMed Central

    Bao, Xingfu; Liu, Xianjun; Zhang, Yi; Cui, Yue; Yao, Jindan

    2014-01-01

    Cementogenesis, performed by cementoblasts, is important for the repair of root resorption caused by orthodontic treatment. Based on recent studies, strontium has been applied for osteoporosis treatment due to its positive effect on osteoblasts. Although promising, the effect of strontium on cementoblasts is still unclear. So the aim of this research was to clarify and investigate the effect of strontium on cementogenesis via employing cementoblasts as model. A series of experiments including MTT, alkaline phosphatase activity, gene analysis, alizarin red staining, and western blot were carried out to evaluate the proliferation and differentiation of cementoblasts. In addition, expression of sclerostin was checked to analyze the possible mechanism. Our results show that strontium inhibits the proliferation of cementoblasts with a dose dependent manner; however, it can promote the differentiation of cementoblasts via downregulating sclerostin expression. Taking together, strontium may facilitate cementogenesis and benefit the treatment of root resorption at a low dose. PMID:25003114

  20. Mechanical strain inhibits repair of airway epithelium in vitro.

    PubMed

    Savla, U; Waters, C M

    1998-06-01

    The repair of airway epithelium after injury is crucial in restoring epithelial barrier integrity. Although the airway epithelium is stretched and compressed due to changes in both circumferential and longitudinal dimensions during respiration and may be overdistended during mechanical ventilation, the effect of cyclic strain on the repair of epithelial wounds is unknown. Human and cat airway epithelial cells were cultured on flexible membranes, wounded by scraping with a metal spatula, and subjected to cyclic strain using the Flexercell Strain Unit. Because the radial strain profile in the wells was nonuniform, we compared closure in regions of elongation and compression within the same well. Both cyclic elongation and cyclic compression significantly slowed repair, with compression having the greatest effect. This attenuation was dependent upon the time of relaxation (TR) during the cycle. When wells were stretched at 10 cycles/min (6 s/cycle) with TR = 5 s, wounds closed similarly to wounds in static wells, whereas in wells with TR = 1 s, significant inhibition was observed. As the TR during cycles increased (higher TR), wounds closed faster. We measured the effect of strain at various TRs on cell area and centroid-centroid distance (CD) as a measure of spreading and migration. While cell area and CD in static wells significantly increased over time, the area and CD of cells in the elongated regions did not change. Cells in compressed regions were significantly smaller, with significantly lower CD. Cell area and CD became progressively larger with increasing TR. These results suggest that mechanical strain inhibits epithelial repair. PMID:9609726

  1. Terpenoids inhibit Candida albicans growth by affecting membrane integrity and arrest of cell cycle.

    PubMed

    Zore, Gajanan B; Thakre, Archana D; Jadhav, Sitaram; Karuppayil, S Mohan

    2011-10-15

    Anti-Candida potential of six terpenoids were evaluated in this study against various isolates of Candida albicans (n=39) and non-C. albicans (n=9) that are differentially susceptible to fluconazole. All the six terpenoids tested, showed excellent activity and were equally effective against isolates of Candida sps., tested in this study. Linalool and citral were the most effective ones, inhibiting all the isolates at ≤0.064% (v/v). Five among the six terpenoids tested were fungicidal. Time dependent kill curve assay showed that MFCs of linalool and eugenol were highly toxic to C. albicans, killing 99.9% inoculum within seven min of exposure, while that of citronellal, linalyl acetate and citral required 15min, 1h and 2h, respectively. FIC index values (Linalool - 0.140, benzyl benzoate - 0.156, eugenol - 0.265, citral - 0.281 and 0.312 for linalyl acetate and citronellal) and isobologram obtained by checker board assay showed that all the six terpenoids tested exhibit excellent synergistic activity with fluconazole against a fluconazole resistant strain of C. albicans. Terpenoids tested arrested C. albicans cells at different phases of the cell cycle i.e. linalool and LA at G1, citral and citronellal at S phase and benzyl benzoate at G2-M phase and induced apoptosis. Linalool, citral, citronellal and benzyl benzoate caused more than 50% inhibition of germ tube induction at 0.008%, while eugenol and LA required 0.032 and 0.016% (v/v) concentrations, respectively. MICs of all the terpenoids for the C. albicans growth were non toxic to HeLa cells. Terpenoids tested exhibited excellent activity against C. albicans yeast and hyphal form growth at the concentrations that are non toxic to HeLa cells. Terpenoids tested in this study may find use in antifungal chemotherapy, not only as antifungal agents but also as synergistic agents along with conventional drugs like fluconazole. PMID:21596542

  2. Tests in vitro and in pots with certain chemicals for inhibition of Pseudomonas solanacearum.

    PubMed

    el-Goorani, M A; Abo-el-Dahab, M K; Wagih, E E

    1978-01-01

    Twenty one isolates of Pseudomonas solanacearum E. F. Smith (Race 3) from various parts of Egypt were inhibited in vitro by Ampicillin, Chloramphenicol, Kanamycin, Oxytetracycline. Tetracycline, Penicillin G, Streptomycin, Nabam (Dithane A-40), Maneb (Dithane M-22), Zinc-ion maneb complex (Dithane M-45), and the insecticide Chlorthion. On the basis of in vitro-sensitivity to the selected 11 chemicals the 21 isolates could not be separated into different groups. Carbendazin (Bavistin), Benomyl, Drazoxolon (Mil-Col), and Temik proved ineffective in inhibiting the in vitro growth of all isolates at all tested concentrations. Preliminary investigations indicate that drenching the soil with solutions of Dithane M-22 (0.25% w/v, Dithane M-45 (0.25%) w/v, or insecticide Chlorthion (50 microgram/ml active ingredient) decreased the incidence of potato wilt disease that developed in soil, artificially infested with P. solanacearum. PMID:696045

  3. Characterization of xanthatin: anticancer properties and mechanisms of inhibited murine melanoma in vitro and in vivo.

    PubMed

    Li, Wei D; Wu, Yu; Zhang, Lei; Yan, Ling G; Yin, Fang Z; Ruan, Jun S; Chen, Zhi P; Yang, Guang M; Yan, Cui P; Zhao, Ding; Lu, Yin; Cai, Bao C

    2013-07-15

    Anti-cancer investigations on Xanthatin mainly focus on in vitro experiments. We herein reported the anti-tumor effects of Xanthatin both in vitro and in vivo. MTS assay results showed that Xanthatin had a remarkable anti-proliferative effect on B16-F10 cells. Moreover, the expression of β-catenin was up-regulated both in vitro and in vivo. Animal studies further revealed that Xanthatin killed the tumor cells around the blood vessels which contributes to reduce microvascular density extremely. All these results indicate that Xanthatin inhibited murine melanoma B16-F10 cell proliferation possibly associated with activation of Wnt/β-catenin pathway and its activity against melanoma tumor might also be relevant to inhibition of angiogenesis. PMID:23664560

  4. Inhibiting the immunoproteasome exacerbates the pathogenesis of systemic Candida albicans infection in mice.

    PubMed

    Mundt, Sarah; Basler, Michael; Buerger, Stefanie; Engler, Harald; Groettrup, Marcus

    2016-01-01

    Apart from its role in MHC class I antigen processing, the immunoproteasome has recently been implicated in the modulation of T helper cell differentiation under polarizing conditions in vitro and in the pathogenesis of autoimmune diseases in vivo. In this study, we investigated the influence of LMP7 on T helper cell differentiation in response to the fungus Candida albicans. We observed a strong effect of ONX 0914, an LMP7-selective inhibitor of the immunoproteasome, on IFN-γ and IL-17A production by murine splenocytes and human peripheral blood mononuclear cells (PBMCs) stimulated with C. albicans in vitro. Using a murine model of systemic candidiasis, we could confirm reduced generation of IFN-γ- and IL-17A-producing cells in ONX 0914 treated mice in vivo. Interestingly, ONX 0914 treatment resulted in increased susceptibility to systemic candidiasis, which manifested at very early stages of infection. Mice treated with ONX 0914 showed markedly increased kidney and brain fungal burden which resulted in enhanced neutrophil recruitment and immunopathology. Together, these results strongly suggest a role of the immunoproteasome in promoting proinflammatory T helper cells in response to C. albicans but also in affecting the innate antifungal immunity in a T helper cell-independent manner. PMID:26776888

  5. Inhibiting the immunoproteasome exacerbates the pathogenesis of systemic Candida albicans infection in mice

    PubMed Central

    Mundt, Sarah; Basler, Michael; Buerger, Stefanie; Engler, Harald; Groettrup, Marcus

    2016-01-01

    Apart from its role in MHC class I antigen processing, the immunoproteasome has recently been implicated in the modulation of T helper cell differentiation under polarizing conditions in vitro and in the pathogenesis of autoimmune diseases in vivo. In this study, we investigated the influence of LMP7 on T helper cell differentiation in response to the fungus Candida albicans. We observed a strong effect of ONX 0914, an LMP7-selective inhibitor of the immunoproteasome, on IFN-γ and IL-17A production by murine splenocytes and human peripheral blood mononuclear cells (PBMCs) stimulated with C. albicans in vitro. Using a murine model of systemic candidiasis, we could confirm reduced generation of IFN-γ- and IL-17A-producing cells in ONX 0914 treated mice in vivo. Interestingly, ONX 0914 treatment resulted in increased susceptibility to systemic candidiasis, which manifested at very early stages of infection. Mice treated with ONX 0914 showed markedly increased kidney and brain fungal burden which resulted in enhanced neutrophil recruitment and immunopathology. Together, these results strongly suggest a role of the immunoproteasome in promoting proinflammatory T helper cells in response to C. albicans but also in affecting the innate antifungal immunity in a T helper cell-independent manner. PMID:26776888

  6. Cinnamon extract inhibits tau aggregation associated with Alzheimer’s Disease in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An aqueous extract of Ceylon cinnamon (C. zeylanicum) was found to inhibit tau aggregation and filament formation, hallmarks of Alzheimer’s disease (AD) in vitro using brain cells taken from patients who died with AD. The extract also promoted complete disassembly of recombinant tau filaments, and ...

  7. IN VITRO CONAZOLE EXPOSURE INHIBITS TESTOSTERONE PRODUCTION IN ADULT AND NEONATAL RAT TESTIS

    EPA Science Inventory

    IN VITRO CONAZOLE EXPOSURE INHIBITS TESTOSTERONE PRODUCTION IN THE ADULT AND NEONATAL TESTIS
    Chad R. Blystone1, 2, David J. Dix2, and John C. Rockett2
    1Department of Environmental and Molecular Toxicology, Box 7633, NC State University, Raleigh, NC 27695, USA and 2U.S. Envi...

  8. Curcumin inhibits the replication of enterovirus 71 in vitro.

    PubMed

    Qin, Ying; Lin, Lexun; Chen, Yang; Wu, Shuo; Si, Xiaoning; Wu, Heng; Zhai, Xia; Wang, Yan; Tong, Lei; Pan, Bo; Zhong, Xiaoyan; Wang, Tianying; Zhao, Wenran; Zhong, Zhaohua

    2014-08-01

    Human enterovirus 71 (EV71) is the main causative pathogen of hand, foot, and mouth disease (HFMD) in children. The epidemic of HFMD has been a public health problem in Asia-Pacific region for decades, and no vaccine and effective antiviral medicine are available. Curcumin has been used as a traditional medicine for centuries to treat a diversity of disorders including viral infections. In this study, we demonstrated that curcumin showed potent antiviral effect again EV71. In Vero cells infected with EV71, the addition of curcumin significantly suppressed the synthesis of viral RNA, the expression of viral protein, and the overall production of viral progeny. Similar with the previous reports, curcumin reduced the production of ROS induced by viral infection. However, the antioxidant property of curcumin did not contribute to its antiviral activity, since N-acetyl-l-cysteine, the potent antioxidant failed to suppress viral replication. This study also showed that extracellular signal-regulated kinase (ERK) was activated by either viral infection or curcumin treatment, but the activated ERK did not interfere with the antiviral effect of curcumin, indicating ERK is not involved in the antiviral mechanism of curcumin. Unlike the previous reports that curcumin inhibited protein degradation through ubiquitin-proteasome system (UPS), we found that curcumin had no impact on UPS in control cells. However, curcumin did reduce the activity of proteasomes which was increased by viral infection. In addition, the accumulation of the short-lived proteins, p53 and p21, was increased by the treatment of curcumin in EV71-infected cells. We further probed the antiviral mechanism of curcumin by examining the expression of GBF1 and PI4KB, both of which are required for the formation of viral replication complex. We found that curcumin significantly reduced the level of both proteins. Moreover, the decreased expression of either GBF1 or PI4KB by the application of siRNAs was sufficient

  9. Curcumin inhibits the replication of enterovirus 71 in vitro

    PubMed Central

    Qin, Ying; Lin, Lexun; Chen, Yang; Wu, Shuo; Si, Xiaoning; Wu, Heng; Zhai, Xia; Wang, Yan; Tong, Lei; Pan, Bo; Zhong, Xiaoyan; Wang, Tianying; Zhao, Wenran; Zhong, Zhaohua

    2014-01-01

    Human enterovirus 71 (EV71) is the main causative pathogen of hand, foot, and mouth disease (HFMD) in children. The epidemic of HFMD has been a public health problem in Asia-Pacific region for decades, and no vaccine and effective antiviral medicine are available. Curcumin has been used as a traditional medicine for centuries to treat a diversity of disorders including viral infections. In this study, we demonstrated that curcumin showed potent antiviral effect again EV71. In Vero cells infected with EV71, the addition of curcumin significantly suppressed the synthesis of viral RNA, the expression of viral protein, and the overall production of viral progeny. Similar with the previous reports, curcumin reduced the production of ROS induced by viral infection. However, the antioxidant property of curcumin did not contribute to its antiviral activity, since N-acetyl-l-cysteine, the potent antioxidant failed to suppress viral replication. This study also showed that extracellular signal-regulated kinase (ERK) was activated by either viral infection or curcumin treatment, but the activated ERK did not interfere with the antiviral effect of curcumin, indicating ERK is not involved in the antiviral mechanism of curcumin. Unlike the previous reports that curcumin inhibited protein degradation through ubiquitin–proteasome system (UPS), we found that curcumin had no impact on UPS in control cells. However, curcumin did reduce the activity of proteasomes which was increased by viral infection. In addition, the accumulation of the short-lived proteins, p53 and p21, was increased by the treatment of curcumin in EV71-infected cells. We further probed the antiviral mechanism of curcumin by examining the expression of GBF1 and PI4KB, both of which are required for the formation of viral replication complex. We found that curcumin significantly reduced the level of both proteins. Moreover, the decreased expression of either GBF1 or PI4KB by the application of siRNAs was

  10. Commercial and Plant Extract Denture Cleansers in Prevention of Candida albicans Growth on Soft Denture Reliner: In Vitro Study

    PubMed Central

    Dhaded, Sunil; Joshi, Shalini

    2016-01-01

    Objective To evaluate and compare the efficacy of two plant extracts and two commercially available denture cleansers against candida albicans adherent to soft denture reline material. Materials and Methods In this study 60 specimens of soft denture reliner material specimens were fabricated with dimensions 10x10x2 mm. The sterile specimens were inoculated by immersion in Sabourand broth containing Candida albicans for 16 hours at 37°C in an incubator. Then the specimens were washed and immersed in denture cleansers which were divided into group five groups from Group I-V for CD Clean®, Nigella sativa, thyme essential oil, Fittydent® and distilled water respectively, for 8 hours at room temperature. Then they were washed, fixed with methanol and stained with crystal violet. Candida cells adherent to the specimens were counted under microscope. The number of cells adherent to test samples were compared with that adherent to control. Results The effectiveness of Fittydent® was more than CD Clean® in reducing the adherent candida albicans and the difference was statically significant (p = <0.001). Both thyme essential oil and nigella sativa were almost same in effectiveness against candida albicans but the difference was not statically significant (p= 0.79). Post-hoc Tukey’s test was performed which indicated that Fittydent® was the most effective amongst the denture cleansers tested in this study, followed by thyme essential oil, nigella sativa and CD Clean®. Conclusion The results of the study showed that all denture cleansers used in the study were significantly effective. The study indicated that Fittydent is more effective amongst the denture cleansers because of its mechanism of action; however the plant extracts used in this study were also significantly effective against candida albicans. PMID:27042584

  11. Artemisinin derivatives inhibit Toxoplasma gondii in vitro at multiple steps in the lytic cycle

    PubMed Central

    D'Angelo, John G.; Bordón, Claudia; Posner, Gary H.; Yolken, Robert; Jones-Brando, Lorraine

    2009-01-01

    Objectives We sought to improve upon the usefulness of artemisinins as anti-Toxoplasma agents by synthesizing new unsaturated, carba derivatives and then testing them for in vitro efficacy against three steps of the lytic cycle of Toxoplasma gondii tachyzoites. Methods Novel derivatives of ART were synthesized and then tested for in vitro antiparasitic activity using T. gondii tachyzoites constitutively expressing β-galactosidase and human fibroblast host cells. Compounds were evaluated for parasite growth inhibition and cytotoxicity, inhibition of replication and inhibition of parasite invasion of host cells. Results Five of the seven new derivatives, 3a–c, 3e and 3f, effectively inhibited T. gondii growth (IC50 = 1.0–4.4 µM); however, only three of these proved to be relatively non-cytotoxic (TD50 ≥ 200 µM). The same five derivatives also inhibited tachyzoite replication, and attachment to and invasion of host cells as effectively as or better than the parent compound ART. In addition, one of the derivatives incapable of inhibiting growth, deoxy-3a, was found to inhibit parasite invasion. Conclusions These new artemisinin derivatives have the ability to inhibit multiple steps of T. gondii's lytic cycle. Synthetic unsaturated, carba derivatives of ART have potential as therapeutic agents for the prevention and treatment of toxoplasmosis in humans. PMID:18988681

  12. Partial inhibition of in vitro pollen germination by simulated solar ultraviolet-B radiation

    SciTech Connect

    Flint, S.D.; Caldwell, M.M.

    1984-01-01

    Pollen from four temperate-latitude taxa were treated with UV radiation in a portion of the UV-B (280-320 nm) waveband during in vitro germination. Inhibition of germination was noted in this pollen compared to samples treated identically except for the exclusion of the UV-B portion of the spectrum. Levels similar to maximum solar UV-B found in temperate-latitude areas failed to inhibit pollen germination significantly, while levels similar to maximum solar UV-B found in equatorial alpine locations caused partial inhibition of germination in three of the four taxa examined.

  13. ROCK Inhibition Facilitates In Vitro Expansion of Glioblastoma Stem-Like Cells

    PubMed Central

    Tilson, Samantha G.; Haley, Elizabeth M.; Triantafillu, Ursula L.; Dozier, David A.; Langford, Catherine P.; Gillespie, G. Yancey; Kim, Yonghyun

    2015-01-01

    Due to their stem-like characteristics and their resistance to existing chemo- and radiation therapies, there is a growing appreciation that cancer stem cells (CSCs) are the root cause behind cancer metastasis and recurrence. However, these cells represent a small subpopulation of cancer cells and are difficult to propagate in vitro. Glioblastoma is an extremely deadly form of brain cancer that is hypothesized to have a subpopulation of CSCs called glioblastoma stem cells (GSCs; also called brain tumor initiating cells, BTICs). We propose the use of selective Rho-kinase (ROCK) inhibitors, Y-27632 and fasudil, to promote GSC/BTIC-like cell survival and propagation in vitro. ROCK inhibitors have been implicated in suppressing apoptosis, and it was hypothesized that they would increase the number of GSC/BTIC-like cells grown in vitro and improve cloning efficiencies. Indeed, our data demonstrate that transient and continuous supplementation of non-toxic concentrations of Y-27632 and fasudil inhibited apoptosis, enhanced the cells’ ability to form spheres, and increased stem cell marker expressing GSC/BTIC-like cell subpopulation. Our data indicated that pharmacological and genetic (siRNA) inhibitions of the ROCK pathway facilitates in vitro expansion of GSC/BTIC-like cells. Thus, ROCK pathway inhibition shows promise for future optimization of CSC culture media. PMID:26167936

  14. In Vitro Susceptibility of Candida Species to Four Antifungal Agents Assessed by the Reference Broth Microdilution Method

    PubMed Central

    Eksi, Fahriye; Gayyurhan, Efgan Dogan; Balci, Iclal

    2013-01-01

    This study was performed to determine the distribution of Candida species isolated from the blood cultures of the patients hospitalized in our hospital and to investigate their antifungal susceptibility. Candida strains were identified at species level by using classical methods and API ID 32C (bioMerieux, France) identification kits. The susceptibility of the strains to amphotericin B, fluconazole, voriconazole, and caspofungin was evaluated by using the reference broth microdilution method in document M27-A3 of the Clinical and Laboratory Standards Institute. Of the 111 Candida strains isolated, 47.7% were identified as C. albicans and 52.3% as non-albicans Candida strains. The MIC ranges were 0.03–1 μg/mL for amphotericin B, 0.125–≥64 μg/mL for fluconazole, 0.03–16 μg/mL for voriconazole, and 0.015–0.25 μg/mL for caspofungin. All Candida strains were susceptible to amphotericin B and caspofungin. 10.8% isolates were resistant to fluconazole and 8.1% isolates were dose-dependent susceptible. While 0.9% isolate was resistant to voriconazole, 0.9% isolate was dose-dependent susceptible. In our study, C. albicans and C. parapsilosis were the most frequently encountered agents of candidemia and it was detected that voriconazole with a low resistance rate might also be used with confidence in the treatment of infections occurring with these agents, primarily besides amphotericin B and caspofungin. PMID:24250260

  15. Inhibition of human platelet function in vitro and ex vivo by acetaminophen.

    PubMed

    Lages, B; Weiss, H J

    1989-03-15

    The effects of acetaminophen (APAP) in vitro, or ex vivo following APAP ingestion, on human platelet aggregation, 14C-5HT secretion, and thromboxane B2 (TxB2) formation were assessed. APAP added in vitro to citrated platelet-rich plasma (PRP) inhibited aggregation, secretion, and TxB2 formation induced by collagen, epinephrine, arachidonate, and the ionophore A23187, but had no effect on the responses induced by the endoperoxide analog U44069. Arachidonate-induced responses were inhibited by lower concentrations of APAP than were the responses to the other agonists. In PRP obtained 1 hour after ingestion of 650 mg or 1000 mg APAP, arachidonate-induced TxB2 formation was inhibited by 40-99% in five subjects tested, whereas inhibition of collagen- or epinephrine-induced TxB2 formation was less consistent. Aggregation and secretion responses were not altered by APAP ingestion in 4 of the 5 subjects, but were inhibited in the remaining subject, who had the highest plasma APAP levels. In contrast to aspirin and indomethacin, APAP-induced inhibition of collagen-stimulated TxB2 formation could be partially overcome with increasing collagen concentrations. No such partial correction occurred with epinephrine, however. In washed platelet suspensions labeled with 3H-arachidonate, both APAP and aspirin inhibited the formation of labeled PGD2 and PGE2, as well as TxB2. These results suggest that APAP acts in human platelets as a reversible inhibitor of cyclo-oxygenase, as found previously in other tissues, and that recent APAP ingestion can, on occasion, produce inhibition of platelet functional responses measured in vitro. PMID:2499947

  16. In vitro inhibition of CYP3A4 by herbal remedies frequently used by cancer patients.

    PubMed

    Engdal, Silje; Nilsen, Odd Georg

    2009-07-01

    The herbal remedies Natto K2, Agaricus, mistletoe, noni juice, green tea and garlic, frequently used by cancer patients, were investigated for their in vitro inhibition potential of cytochrome P-450 3A4 (CYP3A4) metabolism. To our knowledge, only garlic and green tea had available data on the possible inhibition of CYP3A4 metabolism. Metabolic studies were performed with human c-DNA baculovirus expressed CYP3A4. Testosterone was used as a substrate and ketoconazole as a positive quantitative inhibition control. The formation of 6-beta-OH-testosterone was quantified by a validated HPLC methodology. Green tea was the most potent inhibitor of CYP3A4 metabolism (IC(50): 73 microg/mL), followed by Agaricus, mistletoe and noni juice (1324, 3594, >10 000 microg/mL, respectively). All IC(50) values were high compared with those determined for crude extracts of other herbal remedies. The IC(50)/IC(25) ratios for the inhibiting herbal remedies ranged from 2.15 to 2.67, indicating similar inhibition profiles of the herbal inhibitors of CYP3A4. Garlic and Natto K2 were classified as non-inhibitors. Although Agaricus, noni juice, mistletoe and green tea inhibited CYP3A4 metabolism in vitro, clinically relevant systemic or intestinal interactions with CYP3A4 were considered unlikely, except for a probable inhibition of intestinal CYP3A4 by the green tea product. PMID:19170155

  17. Waikialoid A Suppresses Hyphal Morphogenesis and Inhibits Biofilm Development in Pathogenic Candida albicans

    PubMed Central

    Wang, Xiaoru; You, Jianlan; King, Jarrod B.; Powell, Douglas R.; Cichewicz, Robert H.

    2012-01-01

    A chemically prolific strain of Aspergillus was isolated from a soil sample collected near Waikiki Beach, Honolulu, Hawaii. The fungus produced several secondary metabolites that were purified and placed in our natural products library, which was later screened for substances capable of inhibiting biofilm formation by Candida albicans. It was determined that one of the secondary metabolites from the Hawaiian fungal isolate, a new complex prenylated indole alkaloid named waikialoid A (1), inhibited biofilm formation with an IC50 value of 1.4 μM. Another structurally unrelated, presumably polyketide metabolite, waikialide A (15), also inhibited C. albicans biofilm formation, but was much less potent (IC50 value of 32.4 μM). Microscopy studies revealed that compound 1 also inhibited C. albicans hyphal morphogenesis. While metabolite 1 appears ineffective at disrupting preformed biofilms, the accumulated data indicate that the new compound may exert its activity against C. ablicans during the early stages of surface colonization involving cell adherence, hyphal development, and/or biofilm assembly. Unlike some other stephacidin/notoamide compounds, metabolite 1 was not cytotoxic to fungi or human cells (up to 200 μM), which makes this an intriguing model compound for studying the adjunctive use of biofilm inhibitors in combination with standard antifungal antibiotics. PMID:22400916

  18. Waikialoid A suppresses hyphal morphogenesis and inhibits biofilm development in pathogenic Candida albicans.

    PubMed

    Wang, Xiaoru; You, Jianlan; King, Jarrod B; Powell, Douglas R; Cichewicz, Robert H

    2012-04-27

    A chemically prolific strain of Aspergillus was isolated from a soil sample collected near Waikiki Beach, Honolulu, Hawaii. The fungus produced several secondary metabolites, which were purified and placed in our natural products library and were later screened for substances capable of inhibiting biofilm formation by Candida albicans. It was determined that one of the secondary metabolites from the Hawaiian fungal isolate, a new complex prenylated indole alkaloid named waikialoid A (1), inhibited biofilm formation with an IC(50) value of 1.4 μM. Another structurally unrelated, presumably polyketide metabolite, waikialide A (15), also inhibited C. albicans biofilm formation, but was much less potent (IC(50) value of 32.4 μM). Microscopy studies revealed that compound 1 also inhibited C. albicans hyphal morphogenesis. While metabolite 1 appears ineffective at disrupting preformed biofilms, the accumulated data indicate that the new compound may exert its activity against C. albicans during the early stages of surface colonization involving cell adherence, hyphal development, and/or biofilm assembly. Unlike some other stephacidin/notoamide compounds, metabolite 1 was not cytotoxic to fungi or human cells (up to 200 μM), which makes this an intriguing model compound for studying the adjunctive use of biofilm inhibitors in combination with standard antifungal antibiotics. PMID:22400916

  19. Inhibition of benzodiazepine binding in vitro by amentoflavone, a constituent of various species of Hypericum.

    PubMed

    Baureithel, K H; Büter, K B; Engesser, A; Burkard, W; Schaffner, W

    1997-06-01

    Flower extracts of Hypericum perforatum, Hypericum hirsutum, Hypericum patulum and Hypericum olympicum efficiently inhibited binding of [3H]flumazenil to rat brain benzodiazepine binding sites of the GABAA-receptor in vitro with IC50 values of 6.83, 6.97, 13.2 and 6.14 micrograms/ml, respectively. Single constituents of the extracts like hypericin, the flavones quercetin and luteolin, the glycosylated flavonoides rutin, hyperoside and quercitrin and the biflavone 13, II8-biapigenin did not inhibit binding up to concentrations of 1 microM. In contrast, amentoflavone revealed an IC50 = 14.9 +/- 1.9 nM on benzodiazepine binding in vitro. Comparative HPLC analyses of hypericin and amentoflavone in extracts of different Hypericum species revealed a possible correlation between the amentoflavone concentration and the inhibition of flumazenil binding. For hypericin no such correlation was observed. Our experimental data demonstrate that amentoflavone, in contrast to hypericin, presents a very active compound with regard to the inhibition of [3H]-flumazenil binding in vitro and thus might be involved in the antidepressant effects of Hypericum perforatum extracts. PMID:9204773

  20. In vitro inhibition of Helicobacter pylori growth and adherence to gastric mucosal cells by Pycnogenol.

    PubMed

    Rohdewald, Peter; Beil, Winfried

    2008-05-01

    The emergence of antibiotic resistant H. pylori strains has necessitated the identification of alternative additive therapies for the treatment of this infection. The study tested whether a specific pine bark extract (Pycnogenol is effective in inhibiting the growth and adherence of H. pylori in vitro. Inhibition of H. pylori growth by Pycnogenol was tested in liquid medium as well as in an in vitro model by using sessile bacteria attached to AGS cells. Adherence was determined by co-incubation of gastric cells with Pycnogenol and H. pylori in vitro. Pycnogenol inhibited H. pylori growth in suspension with an MIC(50) of 12.5 microg/mL. Growth of H. pylori in infected cells was reduced to 10% of the control value by 125 microg/mL Pycnogenol. Adherence of H. pylori to gastric cells was reduced by 70% after 3 h incubation with 125 microg/mL Pycnogenol. The results show a significant, yet limited inhibition of growth and adherence of H. pylori to gastric cells by Pycnogenol. In vivo studies have to demonstrate the clinical relevance of these findings. PMID:18350522

  1. Lefty inhibits in vitro decidualization by regulating P57 and cyclin D1 expressions.

    PubMed

    Li, Hong; Li, Hui; Bai, Liang; Yu, Hua

    2014-12-01

    Endometrial decidualization is highly important for successful construction and maintenance of embryo implantation and pregnancy. Lefty gene at different menstrual cycle phases has different expressions, indicating its regulatory significance. To study the mechanism of Lefty in decidualization, human endometrial stromal cells (hESCs) were cultured and induced with medroxyprogesterone acetate (MPA) and 8-bromoadenosine-cAMP (8-Br-cAMP) in vitro as a research model. Our results showed that Lefty1 overexpression inhibited MPA- and 8-Br-cAMP-induced hESC decidualization and significantly reduced the secretion of prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP-1). With the inhibition of Lefty1 expression, hESC decidualization induced by MPA and 8-Br-cAMP became more remarkable, and the secretions of PRL and IGFBP-1 were higher too. Further tests indicated that during the process of decidualization, P57 expression increased, whereas cyclin D1 expression decreased. Although Lefty1 overexpression did not significantly change the expressions of P57 and cyclin D1, inhibition of Lefty1 expression resulted in more evident changes in P57 and cyclin D1 expressions. Meanwhile, cell cycle examination showed that Lefty1 overexpression reduced the cell cycle arrest at G1/S phase in the in vitro hESC decidualization model. Therefore, Lefty1 could regulate the cell cycle via modulating the expressions of P57 and cyclin D1 and then inhibit the decidualization in vitro. PMID:25339094

  2. Farnesol biosynthesis in Candida albicans: cellular response to sterol inhibition by zaragozic acid B.

    PubMed

    Hornby, Jacob M; Kebaara, Bessie W; Nickerson, Kenneth W

    2003-07-01

    The dimorphic fungus Candida albicans produces farnesol as a quorum-sensing molecule that regulates cellular morphology. The biosynthetic origin of farnesol has been resolved by treating these cells with zaragozic acid B, a potent inhibitor of squalene synthase in the sterol biosynthetic pathway. Treatment with zaragozic acid B leads to an eightfold increase in the amount of farnesol produced by C. albicans. Furthermore, C. albicans cell extracts contain enzymatic activity to convert [(3)H]farnesyl pyrophosphate to [(3)H]farnesol. Many common antifungal antibiotics (e.g., zaragozic acids, azoles, and allylamines) target steps in sterol biosynthesis. We suggest that the fungicidal activity of zaragozic acid derives in large part from the accumulation of farnesol that accompanies the inhibition of sterol biosynthesis. PMID:12821501

  3. Voriconazole-Induced Inhibition of the Fungicidal Activity of Amphotericin B in Candida Strains with Reduced Susceptibility to Voriconazole: an Effect Not Predicted by the MIC Value Alone ▿

    PubMed Central

    Lignell, Anders; Löwdin, Elisabeth; Cars, Otto; Sanglard, Dominique; Sjölin, Jan

    2011-01-01

    An antagonistic effect of voriconazole on the fungicidal activity of sequential doses of amphotericin B has previously been demonstrated in Candida albicans strains susceptible to voriconazole. Because treatment failure and the need to switch to other antifungals are expected to occur more often in infections that are caused by resistant strains, it was of interest to study whether the antagonistic effect was still seen in Candida strains with reduced susceptibility to voriconazole. With the hypothesis that antagonism will not occur in voriconazole-resistant strains, C. albicans strains with characterized mechanisms of resistance against voriconazole, as well as Candida glabrata and Candida krusei strains with differences in their degrees of susceptibility to voriconazole were exposed to voriconazole or amphotericin B alone, to both drugs simultaneously, or to voriconazole followed by amphotericin B in an in vitro kinetic model. Amphotericin B administered alone or simultaneously with voriconazole resulted in fungicidal activity. When amphotericin B was administered after voriconazole, its activity was reduced (median reduction, 61%; range, 9 to 94%). Levels of voriconazole-dependent inhibition of amphotericin B activity differed significantly among the strains but were not correlated with the MIC values (correlation coefficient, −0.19; P = 0.65). Inhibition was found in C. albicans strains with increases in CDR1 and CDR2 expression but not in the strain with an increase in MDR1 expression. In summary, decreased susceptibility to voriconazole does not abolish voriconazole-dependent inhibition of the fungicidal activity of amphotericin B in voriconazole-resistant Candida strains. The degree of interaction could not be predicted by the MIC value alone. PMID:21282443

  4. Role of disulfiram in the in vitro inhibition of rat liver mitochondrial aldehyde dehydrogenase.

    PubMed

    Shen, M L; Lipsky, J J; Naylor, S

    2000-10-01

    The alcohol aversion therapy drug disulfiram has been shown to inhibit hepatic aldehyde dehydrogenase (ALDH), one of the key enzymes involved in ethanol metabolism. It is believed by some that disulfiram could be one of the active inhibitors in vivo. However, the actual interaction between disulfiram and ALDH remains ambiguous. We report here that when disulfiram inhibited recombinant rat liver mitochondrial ALDH (rlmALDH) in vitro, no significant molecular mass increase was detected during the first 30 min as determined by on-line HPLC-electrospray ionization mass spectrometry (LC-MS). This indicated that the inhibition in vitro was not caused directly by covalent adduct formation on the enzyme. We subsequently subjected both control and disulfiram-inhibited rlmALDH to Glu-C proteolytic digestion. LC-MS analysis of the Glu-C digestion of disulfiram-inhibited enzyme revealed that one peptide of M(r) = 4821, which contained the putative active site of the enzyme, exhibited a mass decrease of 2 amu as compared with the same peptide found in the Glu-C digestion of the control (M(r) = 4823). We believe that the loss of 2 amu indicated that inhibition of rlmALDH in vitro was due to formation of an intramolecular disulfide bond between two of the three adjacent cysteines in the active site, possibly via a very rapid and unstable mixed disulfide interchange reaction. Further confirmation of the intramolecular disulfide bond formation came from the fact that by adding dithiothreitol (DTT) we were able to recover partial enzyme activity. In addition, the peptide of M(r) = 4821 observed in the Glu-C digestion of the disulfiram-treated ALDH reverted to M(r) = 4823 after treatment with DTT, which indicated that the disulfide bond was reduced. We, thereby, conclude that disulfiram inhibited rlmALDH by forming an intramolecular disulfide, possibly via a fast intermolecular disulfiram interchange reaction. PMID:10974203

  5. In Vitro Effect of Malachite Green on Candida albicans Involves Multiple Pathways and Transcriptional Regulators UPC2 and STP2

    PubMed Central

    Dhamgaye, Sanjiveeni; Devaux, Frederic; Manoharlal, Raman; Vandeputte, Patrick; Shah, Abdul Haseeb; Singh, Ashutosh; Blugeon, Corinne; Sanglard, Dominique

    2012-01-01

    In this study, we show that a chemical dye, malachite green (MG), which is commonly used in the fish industry as an antifungal, antiparasitic, and antibacterial agent, could effectively kill Candida albicans and non-C. albicans species. We have demonstrated that Candida cells are susceptible to MG at a very low concentration (MIC that reduces growth by 50% [MIC50], 100 ng ml−1) and that the effect of MG is independent of known antifungal targets, such as ergosterol metabolism and major drug efflux pump proteins. Transcriptional profiling in response to MG treatment of C. albicans cells revealed that of a total of 207 responsive genes, 167 genes involved in oxidative stress, virulence, carbohydrate metabolism, heat shock, amino acid metabolism, etc., were upregulated, while 37 genes involved in iron acquisition, filamentous growth, mitochondrial respiration, etc., were downregulated. We confirmed experimentally that Candida cells exposed to MG resort to a fermentative mode of metabolism, perhaps due to defective respiration. In addition, we showed that MG triggers depletion of intracellular iron pools and enhances reactive oxygen species (ROS) levels. These effects could be reversed by the addition of iron or antioxidants, respectively. We provided evidence that the antifungal effect of MG is exerted through the transcription regulators UPC2 (regulating ergosterol biosynthesis and azole resistance) and STP2 (regulating amino acid permease genes). Taken together, our transcriptome, genetic, and biochemical results allowed us to decipher the multiple mechanisms by which MG exerts its anti-Candida effects, leading to a metabolic shift toward fermentation, increased generation of ROS, labile iron deprivation, and cell necrosis. PMID:22006003

  6. The antidiabetic drug metformin inhibits gastric cancer cell proliferation in vitro and in vivo.

    PubMed

    Kato, Kiyohito; Gong, Jian; Iwama, Hisakazu; Kitanaka, Akira; Tani, Joji; Miyoshi, Hisaaki; Nomura, Kei; Mimura, Shima; Kobayashi, Mitsuyoshi; Aritomo, Yuuichi; Kobara, Hideyuki; Mori, Hirohito; Himoto, Takashi; Okano, Keiichi; Suzuki, Yasuyuki; Murao, Koji; Masaki, Tsutomu

    2012-03-01

    Recent studies suggest that metformin, which is commonly used as an oral anti-hyperglycemic agent of the biguanide family, may reduce cancer risk and improve prognosis, but the mechanisms by which metformin affects various cancers, including gastric cancer, remains unknown. The goal of the present study was to evaluate the effects of metformin on human gastric cancer cell proliferation in vitro and in vivo and to study microRNAs (miRNA) associated with antitumor effect of metformin. We used MKN1, MKN45, and MKN74 human gastric cancer cell lines to study the effects of metformin on human gastric cancer cells. Athymic nude mice bearing xenograft tumors were treated with or without metformin. Tumor growth was recorded after 4 weeks, and the expression of cell-cycle-related proteins was determined. In addition, we used miRNA array tips to explore the differences among miRNAs in MKN74 cells bearing xenograft tumors treated with or without metformin in vitro and in vivo. Metformin inhibited the proliferation of MKN1, MKN45, and MKN74 in vitro. Metformin blocked the cell cycle in G(0)-G(1)in vitro and in vivo. This blockade was accompanied by a strong decrease of G(1) cyclins, especially in cyclin D1, cyclin-dependent kinase (Cdk) 4, Cdk6 and by a decrease in retinoblastoma protein (Rb) phosphorylation. In addition, metformin reduced the phosphorylation of epidermal growth factor receptor and insulin-like growth factor-1 receptor in vitro and in vivo. The miRNA expression was markedly altered with the treatment of metformin in vitro and in vivo. Various miRNAs altered by metformin also may contribute to tumor growth in vitro and in vivo. PMID:22222629

  7. Evaluation of anti-Candida potential of geranium oil constituents against clinical isolates of Candida albicans differentially sensitive to fluconazole: inhibition of growth, dimorphism and sensitization.

    PubMed

    Zore, Gajanan B; Thakre, Archana D; Rathod, V; Karuppayil, S Mohan

    2011-07-01

    Fluconazole (FLC) susceptibility of isolates of Candida spp., (n = 42) and efficacy as well as mechanism of anti-Candida activity of three constituents of geranium oil is evaluated in this study. No fluconazole resistance was observed among the clinical isolates tested, however 22% were susceptible-dose-dependent (S-DD) [minimal inhibitory concentration (MIC) ≥ 16 μg ml(-1)] and a standard strain of C. albicans ATCC 10231 was resistant (≥ 64 μg ml(-1)). Geraniol and geranyl acetate were equally effective, fungicidal at 0.064% v/v concentrations i.e. MICs (561 μg ml(-1) and 584 μg ml(-1) respectively) and killed 99.9% inoculum within 15 and 30 min of exposures respectively. Citronellol was least effective and fungistatic. C. albicans dimorphism (Y → H) was highly sensitive to geranium oil constituents tested (IC50 approximately 0.008% v/v). Geraniol, geranyl acetate and citronellol brought down MICs of FLC by 16-, 32- and 64-fold respectively in a FLC-resistant strain. Citronellol and geraniol arrested cells in G1 phase while geranyl acetate in G2-M phase of cell cycle at MIC(50). In vitro cytotoxicity study revealed that geraniol, geranyl acetate and citronellol were non-toxic to HeLa cells at MICs of the C. albicans growth. Our results indicate that two of the three geranium oil constituents tested exhibit excellent anti-Candida activity and significant synergistic activity with fluconazole. PMID:20337938

  8. PAC-1 activates procaspase-3 in vitro through relief of zinc-mediated inhibition.

    PubMed

    Peterson, Quinn P; Goode, David R; West, Diana C; Ramsey, Kara N; Lee, Joy J Y; Hergenrother, Paul J

    2009-04-24

    The direct induction of apoptosis has emerged as a powerful anticancer strategy, and small molecules that either inhibit or activate certain proteins in the apoptotic pathway have great potential as novel chemotherapeutic agents. Central to apoptosis is the activation of the zymogen procaspase-3 to caspase-3. Caspase-3 is the key "executioner" caspase, catalyzing the hydrolysis of a multitude of protein substrates within the cell. Interestingly, procaspase-3 levels are often elevated in cancer cells, suggesting a compound that directly stimulates the activation of procaspase-3 to caspase-3 could selectively induce apoptosis in cancer cells. We recently reported the discovery of a compound, PAC-1, which enhances procaspase-3 activity in vitro and induces apoptotic death in cancer cells in culture and in mouse xenograft models. Described herein is the mechanism by which PAC-1 activates procaspase-3 in vitro. We show that zinc inhibits the enzymatic activity of procaspase-3 and that PAC-1 strongly activates procaspase-3 in buffers that contain zinc. PAC-1 and zinc form a tight complex with one another, with a dissociation constant of approximately 42 nM. The combined data indicate that PAC-1 activates procaspase-3 in vitro by sequestering inhibitory zinc ions, thus allowing procaspase-3 to autoactivate itself to caspase-3. The small-molecule-mediated activation of procaspases has great therapeutic potential and thus this discovery of the in vitro mechanism of action of PAC-1 is critical to the development and optimization of other procaspase-activating compounds. PMID:19281821

  9. Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis

    PubMed Central

    Lopez-Medina, Eduardo; Fan, Di; Coughlin, Laura A.; Ho, Evi X.; Lamont, Iain L.; Reimmann, Cornelia; Hooper, Lora V.; Koh, Andrew Y.

    2015-01-01

    Bacterial-fungal interactions have important physiologic and medical ramifications, but the mechanisms of these interactions are poorly understood. The gut is host to trillions of microorganisms, and bacterial-fungal interactions are likely to be important. Using a neutropenic mouse model of microbial gastrointestinal colonization and dissemination, we show that the fungus Candida albicans inhibits the virulence of the bacterium Pseudomonas aeruginosa by inhibiting P. aeruginosa pyochelin and pyoverdine gene expression, which plays a critical role in iron acquisition and virulence. Accordingly, deletion of both P. aeruginosa pyochelin and pyoverdine genes attenuates P. aeruginosa virulence. Heat-killed C. albicans has no effect on P. aeruginosa, whereas C. albicans secreted proteins directly suppress P. aeruginosa pyoverdine and pyochelin expression and inhibit P. aeruginosa virulence in mice. Interestingly, suppression or deletion of pyochelin and pyoverdine genes has no effect on P. aeruginosa’s ability to colonize the GI tract but does decrease P. aeruginosa’s cytotoxic effect on cultured colonocytes. Finally, oral iron supplementation restores P. aeruginosa virulence in P. aeruginosa and C. albicans colonized mice. Together, our findings provide insight into how a bacterial-fungal interaction can modulate bacterial virulence in the intestine. Previously described bacterial-fungal antagonistic interactions have focused on growth inhibition or colonization inhibition/modulation, yet here we describe a novel observation of fungal-inhibition of bacterial effectors critical for virulence but not important for colonization. These findings validate the use of a mammalian model system to explore the complexities of polymicrobial, polykingdom infections in order to identify new therapeutic targets for preventing microbial disease. PMID:26313907

  10. Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis.

    PubMed

    Lopez-Medina, Eduardo; Fan, Di; Coughlin, Laura A; Ho, Evi X; Lamont, Iain L; Reimmann, Cornelia; Hooper, Lora V; Koh, Andrew Y

    2015-08-01

    Bacterial-fungal interactions have important physiologic and medical ramifications, but the mechanisms of these interactions are poorly understood. The gut is host to trillions of microorganisms, and bacterial-fungal interactions are likely to be important. Using a neutropenic mouse model of microbial gastrointestinal colonization and dissemination, we show that the fungus Candida albicans inhibits the virulence of the bacterium Pseudomonas aeruginosa by inhibiting P. aeruginosa pyochelin and pyoverdine gene expression, which plays a critical role in iron acquisition and virulence. Accordingly, deletion of both P. aeruginosa pyochelin and pyoverdine genes attenuates P. aeruginosa virulence. Heat-killed C. albicans has no effect on P. aeruginosa, whereas C. albicans secreted proteins directly suppress P. aeruginosa pyoverdine and pyochelin expression and inhibit P. aeruginosa virulence in mice. Interestingly, suppression or deletion of pyochelin and pyoverdine genes has no effect on P. aeruginosa's ability to colonize the GI tract but does decrease P. aeruginosa's cytotoxic effect on cultured colonocytes. Finally, oral iron supplementation restores P. aeruginosa virulence in P. aeruginosa and C. albicans colonized mice. Together, our findings provide insight into how a bacterial-fungal interaction can modulate bacterial virulence in the intestine. Previously described bacterial-fungal antagonistic interactions have focused on growth inhibition or colonization inhibition/modulation, yet here we describe a novel observation of fungal-inhibition of bacterial effectors critical for virulence but not important for colonization. These findings validate the use of a mammalian model system to explore the complexities of polymicrobial, polykingdom infections in order to identify new therapeutic targets for preventing microbial disease. PMID:26313907

  11. In vitro inhibition of multiple cytochrome P450 isoforms by xanthone derivatives from mangosteen extract.

    PubMed

    Foti, Robert S; Pearson, Josh T; Rock, Dan A; Wahlstrom, Jan L; Wienkers, Larry C

    2009-09-01

    Mangosteen is a xanthone-containing fruit found in Southeast Asia for which health claims include maintaining healthy immune and gastrointestinal systems to slowing the progression of tumor growth and neurodegenerative diseases. Previous studies have identified multiple xanthones in the pericarp of the mangosteen fruit. The aim of the current study was to assess the drug inhibition potential of mangosteen in vitro as well as the cytochrome P450 (P450) enzymes responsible for the metabolism of its individual components. The various xanthone derivatives were found to be both substrates and inhibitors for multiple P450 isoforms. Aqueous extracts of the mangosteen pericarp were analyzed for xanthone content as well as inhibition potency. Finally, in vivo plasma concentrations of alpha-mangostin, the most abundant xanthone derivative found in mangosteen, were predicted using Simcyp and found to be well above their respective in vitro K(i) values for CYP2C8 and CYP2C9. PMID:19541824

  12. In vitro inhibition of cytochrome P450 3A4 by Aronia melanocarpa constituents.

    PubMed

    Bräunlich, Marie; Christensen, Hege; Johannesen, Siri; Slimestad, Rune; Wangensteen, Helle; Malterud, Karl E; Barsett, Hilde

    2013-01-01

    Extracts, subfractions, isolated anthocyanins and procyanidins, and two phenolic acids from aronia [Aronia melanocarpa] were investigated for their CYP3A4 inhibitory effects, using midazolam as the probe substrate and recombinant insect cell microsomes expressing CYP3A4 as the enzyme source. Procyanidin B5 was a considerably stronger CYP3A4 inhibitor in vitro than the isomeric procyanidin B2 and comparable to bergamottin, a known CYP3A4 inhibitor from grapefruit juice. The inhibitory activity of proanthocyanidin-containing fractions was correlated to the degree of polymerization. Among the anthocyanins, cyanidin 3-arabinoside showed stronger CYP3A4 inhibition than cyanidin 3-galactoside and cyanidin 3-glucoside. Thus, the ability to inhibit CYP3A4 in vitro seems to be influenced by the sugar unit linked to the anthocyanidin. PMID:23250807

  13. Growth Inhibition and Membrane Permeabilization of Candida lusitaniae Using Varied Pulse Shape Electroporation

    PubMed Central

    Novickij, V.; Grainys, A.; Lastauskienė, E.; Kananavičiūtė, R.; Pamedytytė, D.; Zinkevičienė, A.; Kalėdienė, L.; Novickij, J.; Paškevičius, A.; Švedienė, J.

    2015-01-01

    Candida lusitaniae is an opportunistic yeast pathogen, which can readily develop resistance to antifungal compounds and result in a complex long-term treatment. The efficient treatment is difficult since structure and metabolic properties of the fungal cells are similar to those of eukaryotic host. One of the potential methods to improve the inhibition rate or the cell permeability to inhibitors is the application of electroporation. In this work we investigated the dynamics of the growth inhibition and membrane permeabilization of C. lusitaniae by utilizing the various pulse shape and duration electric field pulses. Our results indicated that single electroporation procedure using 8 kV/cm electric field may result in up to 51 ± 5% inhibition rate. Also it has been experimentally shown that the electroporation pulse shape may influence the inhibitory effect; however, the amplitude of the electric field and the pulse energy remain the most important parameters for definition of the treatment outcome. The dynamics of the cell membrane permeabilization in the 2–8 kV/cm electric field were overviewed. PMID:26697485

  14. Paridis saponins inhibiting carcinoma growth and metastasis in vitro and in vivo.

    PubMed

    Shuli, Man; Wenyuan, Gao; Yanjun, Zhang; Chaoyi, Ma; Liu, Yang; Yiwen, Li

    2011-01-01

    Paris polyphylla Smith var. yunnanensis extracts, Rhizoma Paridis saponins (RPS) have been found to show strong antitumor activity. However, few studies have yet investigated pulmonary metastasis treatment with this herb. To detail the effective components in RPS and discuss the preliminary mechanism of antitumor effects in vivo and in vitro, a mixture isolated from RPS was investigated. The main constituents were identified as polyphyllin D, formosanin C, dioscin, Paris H, Paris VII and pennogennin 3-O-α-L-rhamnopyranosyl (1→4)-[β-L-rhamnopyranosyl (1→2)]-β-D-glucopyranoside. In our experiments, LA795 cells were exposed to the mixed compounds. Migration inhibition was evaluated by wound healing assay and migration assay in non-cytotoxic dose which was determined by MTT assay. The results demonstrated that the constituent in varying degrees inhibited the migration of the tumor cells in vitro. The mixture also showed antitumor effects on carcinoma in vivo. In conclusion, the mixture is a potent anticancer agent that elicits programmed cell death and inhibits the migration in murine lung adenocarcinoma, both in vitro and in vivo. PMID:21468914

  15. Nanosized particles of orlistat with enhanced in vitro dissolution rate and lipase inhibition.

    PubMed

    Dolenc, Andrej; Govedarica, Biljana; Dreu, Rok; Kocbek, Petra; Srcic, Stane; Kristl, Julijana

    2010-08-30

    Orlistat is locally acting inhibitor of gastrointestinal lipases which has been developed for the treatment of obesity. The present study was designed with the intent to formulate orlistat in a different way compared to the current practice and investigate its inhibition of gastrointestinal lipases. Orlistat is considered as a technologically problematic and unmanageable substance because of waxy nature, low melting point and low chemical stability. The manuscript presents the critical issues regarding engineering of its nanosuspension with controlled particle size by melt emulsification and high pressure homogenization. In order to formulate dry product, lactose was dissolved in nanosuspension as filler and spray drying has been performed for obtaining the final powder product. Laser diffraction, scanning electron microscopy and atomic force microscopy have been used for orlistat nanosuspension characterization, dissolution studies and lipase inhibition studies were performed to characterize the in vitro efficacy of formulated orlistat. The advantage of selected technological procedures is nanosized orlistat with elevated in vitro dissolution rate in comparison to raw drug, physical mixture and marketed product. Furthermore, nanosuspension demonstrated significantly higher in vitro lipase inhibition in comparison to references. To conclude, the results show new technological solution and remarkable increase of pharmacological effect which could potentially lead to decreasing the dose and consequently dose dependent side effects. PMID:20540997

  16. An aqueous pomegranate peel extract inhibits neutrophil myeloperoxidase in vitro and attenuates lung inflammation in mice.

    PubMed

    Bachoual, Rafik; Talmoudi, Wifak; Boussetta, Tarek; Braut, Françoise; El-Benna, Jamel

    2011-06-01

    Punica granatum peel aqueous extract (PGE) is widely used to treat disorders such as inflammation, ulcers and infections, but its pharmacological target is not known. In this study we investigated the effect of PGE on human neutrophil reactive oxygen species (ROS) production in vitro and on LPS-induced lung inflammation in vivo in mice. Neutrophils were isolated and ROS generation was measured by luminol-amplified chemiluminescence. Superoxide anion generation was detected by the cytochrome c reduction assay. H(2)O(2) was detected by DCFH fluorescence assay. Myeloperoxidase (MPO) activity was measured by the tetramethyl benzidine oxidation method. Lung inflammation was induced in mice by LPS instillation. PGE inhibited luminol-amplified chemiluminescence of resting neutrophils and N-formyl-methionyl-leucyl-phenylalanine (fMLF)- or phorbol myristate acetate (PMA)-stimulated neutrophils, in a concentration-dependent manner. PGE had no effect on superoxide anion generation, suggesting that it does not directly inhibit NADPH oxidase activity or activation pathways, or scavenge superoxide anions. PGE did not scavenge H(2)O(2) but directly inhibited myeloperoxidase activity in vitro. In vivo studies showed that PGE also attenuated LPS-induced lung inflammation in mice. So this study reveals that PGE inhibits neutrophil MPO activity and attenuates LPS-induced lung inflammation in mice. Inhibition of MPO activity by PGE could explain its anti-inflammatory action. PMID:21376769

  17. The Effect of Cyclooxygenase Inhibition on Tendon-Bone Healing in an In Vitro Coculture Model

    PubMed Central

    Schwarting, Tim; Pretzsch, Sebastian; Debus, Florian; Ruchholtz, Steffen; Lechler, Philipp

    2015-01-01

    The effects of cyclooxygenase (COX) inhibition following the reconstruction of the anterior cruciate ligament remain unclear. We examined the effects of selective COX-2 and nonselective COX inhibition on bone-tendon integration in an in vitro model. We measured the dose-dependent effects of ibuprofen and parecoxib on the viability of lipopolysaccharide- (LPS-) stimulated and unstimulated mouse MC3T3-E1 and 3T3 cells, the influence on gene expression at the osteoblast, interface, and fibroblast regions measured by quantitative PCR, and cellular outgrowth assessed on histological sections. Ibuprofen led to a dose-dependent suppression of MC3T3 cell viability, while parecoxib reduced the viability of 3T3 cultures. Exposure to ibuprofen significantly suppressed expression of Alpl (P < 0.01), Bglap (P < 0.001), and Runx2 (P < 0.01), and although parecoxib reduced expression of Alpl (P < 0.001), Fmod (P < 0.001), and Runx2 (P < 0.01), the expression of Bglap was increased (P < 0.01). Microscopic analysis showed a reduction in cellular outgrowth in LPS-stimulated cultures following exposure to ibuprofen and parecoxib. Nonselective COX inhibition and the specific inhibition of COX-2 led to region-specific reductions in markers of calcification and cell viability. We suggest further in vitro and in vivo studies examining the biologic and biomechanical effects of selective and nonselective COX inhibition. PMID:26063979

  18. The Effect of Cyclooxygenase Inhibition on Tendon-Bone Healing in an In Vitro Coculture Model.

    PubMed

    Schwarting, Tim; Pretzsch, Sebastian; Debus, Florian; Ruchholtz, Steffen; Lechler, Philipp

    2015-01-01

    The effects of cyclooxygenase (COX) inhibition following the reconstruction of the anterior cruciate ligament remain unclear. We examined the effects of selective COX-2 and nonselective COX inhibition on bone-tendon integration in an in vitro model. We measured the dose-dependent effects of ibuprofen and parecoxib on the viability of lipopolysaccharide- (LPS-) stimulated and unstimulated mouse MC3T3-E1 and 3T3 cells, the influence on gene expression at the osteoblast, interface, and fibroblast regions measured by quantitative PCR, and cellular outgrowth assessed on histological sections. Ibuprofen led to a dose-dependent suppression of MC3T3 cell viability, while parecoxib reduced the viability of 3T3 cultures. Exposure to ibuprofen significantly suppressed expression of Alpl (P < 0.01), Bglap (P < 0.001), and Runx2 (P < 0.01), and although parecoxib reduced expression of Alpl (P < 0.001), Fmod (P < 0.001), and Runx2 (P < 0.01), the expression of Bglap was increased (P < 0.01). Microscopic analysis showed a reduction in cellular outgrowth in LPS-stimulated cultures following exposure to ibuprofen and parecoxib. Nonselective COX inhibition and the specific inhibition of COX-2 led to region-specific reductions in markers of calcification and cell viability. We suggest further in vitro and in vivo studies examining the biologic and biomechanical effects of selective and nonselective COX inhibition. PMID:26063979

  19. ROCK inhibition enhances neurite outgrowth in neural stem cells by upregulating YAP expression in vitro

    PubMed Central

    Jia, Xu-feng; Ye, Fei; Wang, Yan-bo; Feng, Da-xiong

    2016-01-01

    Spontaneous axonal regeneration of neurons does not occur after spinal cord injury because of inhibition by myelin and other inhibitory factors. Studies have demonstrated that blocking the Rho/Rho-kinase (ROCK) pathway can promote neurite outgrowth in spinal cord injury models. In the present study, we investigated neurite outgrowth and neuronal differentiation in neural stem cells from the mouse subventricular zone after inhibition of ROCK in vitro. Inhibition of ROCK with Y-27632 increased neurite length, enhanced neuronal differentiation, and upregulated the expression of two major signaling pathway effectors, phospho-Akt and phospho-mitogen-activated protein kinase, and the Hippo pathway effector YAP. These results suggest that inhibition of ROCK mediates neurite outgrowth in neural stem cells by activating the Hippo signaling pathway. PMID:27482229

  20. A Trypsin Inhibitor from Tecoma stans Leaves Inhibits Growth and Promotes ATP Depletion and Lipid Peroxidation in Candida albicans and Candida krusei.

    PubMed

    Patriota, Leydianne L S; Procópio, Thamara F; de Souza, Maria F D; de Oliveira, Ana Patrícia S; Carvalho, Lidiane V N; Pitta, Maira G R; Rego, Moacyr J B M; Paiva, Patrícia M G; Pontual, Emmanuel V; Napoleão, Thiago H

    2016-01-01

    Tecoma stans (yellow elder) has shown medicinal properties and antimicrobial activity. Previous reports on antifungal activity of T. stans preparations and presence of trypsin inhibitor activity from T. stans leaves stimulated the investigation reported here. In this work, we proceeded to the purification and characterization of a trypsin inhibitor (TesTI), which was investigated for anti-Candida activity. Finally, in order to determine the potential of TesTI as a new natural chemotherapeutic product, its cytotoxicity to human peripheral blood mononuclear cells (PBMCs) was evaluated. TesTI was isolated from saline extract by ammonium sulfate fractionation followed by ion exchange and gel filtration chromatographies. Antifungal activity was evaluated by determining the minimal inhibitory (MIC) and fungicide (MFC) concentrations using fungal cultures containing only yeast form or both yeast and hyphal forms. Candida cells treated with TesTI were evaluated for intracellular ATP levels and lipid peroxidation. Cytotoxicity of TesTI to PBMCs was evaluated by MTT assay. TesTI (39.8 kDa, pI 3.41, K i 43 nM) inhibited similarly the growth of both C. albicans and C. krusei culture types at MIC of 100 μg/mL. The MFCs were 200 μg/mL for C. albicans and C. krusei. Time-response curves revealed that TesTI (at MIC) was more effective at inhibiting the replication of C. albicans cells. At MIC, TesTI promoted reduction of ATP levels and lipid peroxidation in the Candida cells, being not cytotoxic to PBMCs. In conclusion, TesTI is an antifungal agent against C. albicans and C. krusei, without toxicity to human cells. PMID:27199940

  1. A Trypsin Inhibitor from Tecoma stans Leaves Inhibits Growth and Promotes ATP Depletion and Lipid Peroxidation in Candida albicans and Candida krusei

    PubMed Central

    Patriota, Leydianne L. S.; Procópio, Thamara F.; de Souza, Maria F. D.; de Oliveira, Ana Patrícia S.; Carvalho, Lidiane V. N.; Pitta, Maira G. R.; Rego, Moacyr J. B. M.; Paiva, Patrícia M. G.; Pontual, Emmanuel V.; Napoleão, Thiago H.

    2016-01-01

    Tecoma stans (yellow elder) has shown medicinal properties and antimicrobial activity. Previous reports on antifungal activity of T. stans preparations and presence of trypsin inhibitor activity from T. stans leaves stimulated the investigation reported here. In this work, we proceeded to the purification and characterization of a trypsin inhibitor (TesTI), which was investigated for anti-Candida activity. Finally, in order to determine the potential of TesTI as a new natural chemotherapeutic product, its cytotoxicity to human peripheral blood mononuclear cells (PBMCs) was evaluated. TesTI was isolated from saline extract by ammonium sulfate fractionation followed by ion exchange and gel filtration chromatographies. Antifungal activity was evaluated by determining the minimal inhibitory (MIC) and fungicide (MFC) concentrations using fungal cultures containing only yeast form or both yeast and hyphal forms. Candida cells treated with TesTI were evaluated for intracellular ATP levels and lipid peroxidation. Cytotoxicity of TesTI to PBMCs was evaluated by MTT assay. TesTI (39.8 kDa, pI 3.41, Ki 43 nM) inhibited similarly the growth of both C. albicans and C. krusei culture types at MIC of 100 μg/mL. The MFCs were 200 μg/mL for C. albicans and C. krusei. Time-response curves revealed that TesTI (at MIC) was more effective at inhibiting the replication of C. albicans cells. At MIC, TesTI promoted reduction of ATP levels and lipid peroxidation in the Candida cells, being not cytotoxic to PBMCs. In conclusion, TesTI is an antifungal agent against C. albicans and C. krusei, without toxicity to human cells. PMID:27199940

  2. Low-dose methotrexate inhibits methionine S-adenosyltransferase in vitro and in vivo.

    PubMed

    Wang, Yi-Cheng; Chiang, En-Pei Isabel

    2012-01-01

    Methionine S-adenosyltransferase (MAT) catalyzes the only reaction that produces the major methyl donor in mammals. Low-dose methotrexate is the most commonly used disease-modifying antirheumatic drug in human rheumatic conditions. The present study was conducted to test the hypothesis that methotrexate inhibits MAT expression and activity in vitro and in vivo. HepG2 cells were cultured under folate restriction or in low-dose methotrexate with and without folate or methionine supplementation. Male C57BL/6J mice received methotrexate regimens that reflected low-dose clinical use in humans. S-adenosylmethionine and MAT genes, proteins and enzyme activity levels were determined. We found that methionine or folate supplementation greatly improved S-adenosylmethionine in folate-depleted cells but not in cells preexposed to methotrexate. Methotrexate but not folate depletion suppressed MAT genes, proteins and activity in vitro. Low-dose methotrexate inhibited MAT1A and MAT2A genes, MATI/II/III proteins and MAT enzyme activities in mouse tissues. Concurrent folinate supplementation with methotrexate ameliorated MAT2A reduction and restored S-adenosylmethionine in HepG2 cells. However, posttreatment folinate rescue failed to restore MAT2A reduction or S-adenosylmethionine level in cells preexposed to methotrexate. Our results provide both in vitro and in vivo evidence that low-dose methotrexate inhibits MAT genes, proteins, and enzyme activity independent of folate depletion. Because polyglutamated methotrexate stays in the hepatocytes, if methotrexate inhibits MAT in the liver, then the efficacy of clinical folinate rescue with respect to maintaining hepatic S-adenosylmethionine synthesis and normalizing the methylation reactions would be limited. These findings raise concerns on perturbed methylation reactions in humans on low-dose methotrexate. Future studies on the clinical physiological consequences of MAT inhibition by methotrexate and the potential benefits of S

  3. Inhibitive effect of diphenytriazol on rat cytochrome P450 enzyme in vitro.

    PubMed

    Hu, Y Z; Yao, T W

    2009-07-01

    The inhibiting effect of diphenytriazol, a non-hormonal early pregnancy-terminating agent, towards cytochrome P450 (CYP) enzymes in rat liver microsomes was studied in vitro. The inhibiting effect of diphenytriazol on CYP was investigated by coincubating diphenytriazol with the specific CYP1A substrates, ethoxyresorufin and phenacetin, in microsome induced by beta-naphthoflavone, with the specific CYP2B substrates, pentoxyresorufin and aminopyrine, in the microsome induced by phenobarbital, and with the specific CYP3A substrates, diazepam, testosterone, nifedipine and quinine sulfate in microsome induced by dexamethasone. The results showed that diphenytriazol inhibited the metabolism of ethoxyresorufin and phenacetin significantly, and its inhibition potential on CYP1A was higher than the typical inhibitor fluvoxamine. Diphenytriazol also inhibited the metabolism of diazepam, testosterone, nifedipine and quinine sulfate to different degrees, but its inhibition potential was relatively weaker than that of the typical inhibitor, ketoconazole. No inhibiting effect of diphenytriazol was seen on the metabolism of pentoxyresorufin and aminopyrine. The ability of diphenytriazol to inhibit rat liver CYP1A and CYP3A suggests that in human patients complex interactions may result from co-adiministration of diphenytriazol with other agents which are also substrates for CYP1A or CYP3A enzymes. PMID:19694183

  4. Seminal plasma proteins inhibit in vitro- and cooling-induced capacitation in boar spermatozoa.

    PubMed

    Vadnais, Melissa L; Roberts, Kenneth P

    2010-01-01

    Dilute boar seminal plasma (SP) has been shown to inhibit in vitro capacitation and cooling-induced capacitation-like changes in boar spermatozoa, as assessed by the ability of the spermatozoa to undergo an ionophore-induced acrosome reaction. We hypothesised that the protein component of SP is responsible for this effect. To test this hypothesis, varying concentrations of total SP protein or SP proteins fractionated by heparin binding were assayed for their ability to inhibit in vitro capacitation, as well as cooling- and cryopreservation-induced capacitation-like changes. In vitro capacitation and cooling-induced capacitation-like changes were prevented by 10% whole SP, as well as by total proteins extracted from SP at concentrations greater than 500 microg mL(-1). No amount of SP protein was able to prevent cryopreservation-induced capacitation-like changes. Total SP proteins were fractionated based on their heparin-binding properties and the heparin-binding fraction was shown to possess capacitation inhibitory activity at concentrations as low as 250 microg mL(-1). The proteins in the heparin-binding fraction were subjected to mass spectrometry and identified. The predominant proteins were three members of the spermadhesin families, namely AQN-3, AQN-1 and AWN, and SP protein pB1. We conclude that one or more of these heparin-binding SP proteins is able to inhibit in vitro capacitation and cooling-induced capacitation-like changes, but not cryopreservation-induced capacitation-like changes, in boar spermatozoa. PMID:20591323

  5. Bismuth oxide aqueous colloidal nanoparticles inhibit Candida albicans growth and biofilm formation

    PubMed Central

    Hernandez-Delgadillo, Rene; Velasco-Arias, Donaji; Martinez-Sanmiguel, Juan Jose; Diaz, David; Zumeta-Dube, Inti; Arevalo-Niño, Katiushka; Cabral-Romero, Claudio

    2013-01-01

    Multiresistance among microorganisms to common antimicrobials has become one of the most significant concerns in modern medicine. Nanomaterials are a new alternative to successfully treat the multiresistant microorganisms. Nanostructured materials are used in many fields, including biological sciences and medicine. Recently, it was demonstrated that the bactericidal activity of zero-valent bismuth colloidal nanoparticles inhibited the growth of Streptococcus mutans; however the antimycotic potential of bismuth nanostructured derivatives has not yet been studied. The main objective of this investigation was to analyze the fungicidal activity of bismuth oxide nanoparticles against Candida albicans, and their antibiofilm capabilities. Our results showed that aqueous colloidal bismuth oxide nanoparticles displayed antimicrobial activity against C. albicans growth (reducing colony size by 85%) and a complete inhibition of biofilm formation. These results are better than those obtained with chlorhexidine, nystatin, and terbinafine, the most effective oral antiseptic and commercial antifungal agents. In this work, we also compared the antimycotic activities of bulk bismuth oxide and bismuth nitrate, the precursor metallic salt. These results suggest that bismuth oxide colloidal nanoparticles could be a very interesting candidate as a fungicidal agent to be incorporated into an oral antiseptic. Additionally, we determined the minimum inhibitory concentration for the synthesized aqueous colloidal Bi2O3 nanoparticles. PMID:23637533

  6. Terpenoids of plant origin inhibit morphogenesis, adhesion, and biofilm formation by Candida albicans.

    PubMed

    Raut, Jayant S; Shinde, Ravikumar B; Chauhan, Nitin M; Karuppayil, S Mohan

    2013-01-01

    Biofilm-related infections caused by Candida albicans and associated drug resistant micro-organisms are serious problems for immunocompromised populations. Molecules which can prevent or remove biofilms are needed. Twenty-eight terpenoids of plant origin were analysed for their activity against growth, virulence attributes, and biofilms of C. albicans. Eighteen molecules exhibited minimum inhibitory concentrations of <2 mg ml(-1) for planktonic growth. Selected molecules inhibited yeast to hyphal dimorphism at low concentrations (0.031-0.5 mg ml(-1)), while adhesion to a solid surface was prevented at 0.5-2 mg ml(-1). Treatment with 14 terpenoids resulted in significant (p < 0.05) inhibition of biofilm formation, and of these, linalool, nerol, isopulegol, menthol, carvone, α-thujone, and farnesol exhibited biofilm-specific activity. Eight terpenoids were identified as inhibitors of mature biofilms. This study demonstrated the antibiofilm potential of terpenoids, which need to be further explored as therapeutic strategy against biofilm associated infections of C. albicans. PMID:23216018

  7. Sesquiterpenes from Carpesium macrocephalum inhibit Candida albicans biofilm formation and dimorphism.

    PubMed

    Xie, Chunfeng; Sun, Lingmei; Meng, Linghao; Wang, Meicheng; Xu, Jing; Bartlam, Mark; Guo, Yuanqiang

    2015-11-15

    One new xanthanolide, 4-(2-methybutyryl)-4H-tomentosin (1) was isolated from the whole plant of Carpesium macrocephalum together with nine known sesquiterpenes (2-10), including four eudesmane sesquiterpenes (2, 4, 5, and 10), one guaianolide (3), two xanthanolides (6 and 9) and two carabranolides (7 and 8). Their structures were elucidated on the basis of detailed spectroscopic analyses. All isolates were evaluated for their antifungal activities against the growth, biofilm formation and yeast-hyphal transition in Candida albicans. All compounds lacked the antifungal activity (MIC50>256 μg/ml) except compound 6 with the MIC50 value of 128 μg/ml. However, compounds 3, 5 and 10 strongly inhibited biofilm formation with IC50 values ranging from 15.4 to 38.0 μg/mL, and compounds 1, 3, 4, 6 and 7 inhibited the yeast-to-hyphae morphogenetic transition with the IC50 values between 31.6 and 118.4 μg/mL. The above results indicated that sesquiterpenes from C. macrocephalum may have therapeutic potential for candidiasis as virulence inhibitors. PMID:26394911

  8. Oligonucleotide directed misfolding of RNA inhibits Candida albicans group I intron splicing

    PubMed Central

    Childs, Jessica L.; Disney, Matthew D.; Turner, Douglas H.

    2002-01-01

    RNA is becoming an important therapeutic target. Many potential RNA targets require secondary or tertiary structure for function. Examples include ribosomal RNAs, RNase P RNAs, mRNAs with untranslated regions that regulate translation, and group I and group II introns. Here, a method is described to inhibit RNA function by exploiting the propensity of RNA to adopt multiple folded states that are of similar free energy. This method, called oligonucleotide directed misfolding of RNA (ODMiR), uses short oligonucleotides to stabilize inactive structures. The ODMiR method is demonstrated with the group I intron from Candida albicans, a human pathogen. The oligonucleotides, L(TACCTTTC) and TLCTLACLGALCGLGCLC, with L denoting a locked nucleic acid residue, inhibit 50% of group I intron splicing in a transcription mixture at about 150 and 30 nM oligonucleotide concentration, respectively. Both oligonucleotides induce misfolds as determined by native gel electrophoresis and diethyl pyrocarbonate modification. The ODMiR approach provides a potential therapeutic strategy applicable to RNAs with secondary or tertiary structures required for function. PMID:12169671

  9. Inhibition of influenza A virus infection in vitro by saliphenylhalamide-loaded porous silicon nanoparticles.

    PubMed

    Bimbo, Luis M; Denisova, Oxana V; Mäkilä, Ermei; Kaasalainen, Martti; De Brabander, Jef K; Hirvonen, Jouni; Salonen, Jarno; Kakkola, Laura; Kainov, Denis; Santos, Hélder A

    2013-08-27

    Influenza A viruses (IAVs) cause recurrent epidemics in humans, with serious threat of lethal worldwide pandemics. The occurrence of antiviral-resistant virus strains and the emergence of highly pathogenic influenza viruses have triggered an urgent need to develop new anti-IAV treatments. One compound found to inhibit IAV, and other virus infections, is saliphenylhalamide (SaliPhe). SaliPhe targets host vacuolar-ATPase and inhibits acidification of endosomes, a process needed for productive virus infection. The major obstacle for the further development of SaliPhe as antiviral drug has been its poor solubility. Here, we investigated the possibility to increase SaliPhe solubility by loading the compound in thermally hydrocarbonized porous silicon (THCPSi) nanoparticles. SaliPhe-loaded nanoparticles were further investigated for the ability to inhibit influenza A infection in human retinal pigment epithelium and Madin-Darby canine kidney cells, and we show that upon release from THCPSi, SaliPhe inhibited IAV infection in vitro and reduced the amount of progeny virus in IAV-infected cells. Overall, the PSi-based nanosystem exhibited increased dissolution of the investigated anti-IAV drug SaliPhe and displayed excellent in vitro stability, low cytotoxicity, and remarkable reduction of viral load in the absence of organic solvents. This proof-of-principle study indicates that PSi nanoparticles could be used for efficient delivery of antivirals to infected cells. PMID:23889734

  10. Potassium humate inhibits complement activation and the production of inflammatory cytokines in vitro

    SciTech Connect

    van Rensburg, C.E.J.; Naude, P.J.

    2009-08-15

    The effects of brown coal derived potassium humate on lymphocyte proliferation, cytokine production and complement activation were investigated in vitro. Potassium humate increased lymphocyte proliferation of phytohaemaglutinin A (PHA) and pokeweed mitogen (PWM) stimulated mononuclear lymphocytes (MNL) in vitro from concentrations of 20 to 80 {mu} g/ml, in a dose dependant manner. On the other hand potassium humate, at 40 {mu} g/ml, significantly inhibited the release of TNF-alpha, IL-1 beta, IL-6 and IL-10 by PHA stimulated MNL. Regarding complement activation it was found that potassium humate inhibits the activation of both the alternative and classical pathways without affecting the stability of the red blood cell membranes. These results indicate that the anti-inflammatory potential of potassium humate could be partially due to the inhibition of pro-inflammatory cytokines responsible for the initiation of these reactions as well as inhibition of complement activation. The increased lymphocyte proliferation observed, might be due to increased IL-2 production as previously been documented.

  11. Inhibitory effect of ebselen on cerebral acetylcholinesterase activity in vitro: kinetics and reversibility of inhibition.

    PubMed

    Martini, Franciele; Bruning, César Augusto; Soares, Suelen Mendonca; Nogueira, Cristina Wayne; Zeni, Gilson

    2015-01-01

    Ebselen is a synthetic organoselenium compound that has been considered a potential pharmacological agent with low toxicity, showing antioxidant, anti-inflammatory and neuroprotective effects. It is bioavailable, blood-brain barrier permeant and safe based on cellular toxicity and Phase I-III clinical trials. There is evidence that ebselen inhibits acetylcholinesterase (AChE) activity, an enzyme that plays a key role in the cholinergic system by hydrolyzing acetylcholine (ACh), in vitro and ex vivo. This system has a well-known relationship with cognitive process, and AChE inhibitors, such as donepezil and galantamine, have been used to treat cognitive deficits, mainly in the Alzheimer's Disease (AD). However, these drugs have poor bioavailability and a number of side effects, including gastrointestinal upsets and hepatotoxicity. In this way, this study aimed to evaluate the effect of ebselen on cerebral AChE activity in vitro and to determine the kinetic profile and the reversibility of inhibition by dialysis. Ebselen inhibited the cerebral AChE activity with an IC50 of 29 µM, similar to IC50 found with pure AChE from electric eel, demonstrating a mixed and reversible inhibition of AChE, since it increased Km and decreased Vmax. The AChE activity was recovered within 60 min of dialysis. Therefore, the use of ebselen as a therapeutic agent for treatment of AD should be considered, although memory behavior tasks are needed to support such hypothesis. PMID:25312723

  12. Correlation between in vivo and in vitro studies of modulation of resistance to experimental Candida albicans infection by cyclophosphamide in mice.

    PubMed

    Bistoni, F; Baccarini, M; Blasi, E; Marconi, P; Puccetti, P; Garaci, E

    1983-04-01

    Mice receiving a single injection of cyclophosphamide (150 mg/kg) 1 to 6 days before inoculation with viable Candida albicans showed an increased susceptibility to the challenge accompanied by a reduction in peripheral blood polymorphonuclear leukocytes and lymphocytes as well as in spleen cellularity. Several immunological in vitro functions also appeared to be dramatically depressed. Most of these hematological and functional parameters returned to control values by day 9 after cyclophosphamide administration, at a time when resistance to C. albicans infection appeared to be unchanged. However, when exposure to cyclophosphamide occurred 12 to 21 days before inoculation with the live yeast, enhanced resistance was observed with the majority of the animals surviving challenge. To gain some insight into the mechanisms underlying this late increase in resistance to C. albicans infection after cyclophosphamide administration, we analyzed a series of immunological functions, including the in vitro candidacidal activity of polymorphonuclear neutrophils and plastic-adherent and nonadherent spleen cells as well as the activity of natural killer cells and alloreactive T lymphocytes. The results show that a numerical rebound of blood polymorphonuclear neutrophils and the appearance of a highly candidacidal cell population in the spleen may be among the factors underlying the late increase in resistance to C. albicans after administration of cyclophosphamide. PMID:6339410

  13. Correlation between in vivo and in vitro studies of modulation of resistance to experimental Candida albicans infection by cyclophosphamide in mice.

    PubMed Central

    Bistoni, F; Baccarini, M; Blasi, E; Marconi, P; Puccetti, P; Garaci, E

    1983-01-01

    Mice receiving a single injection of cyclophosphamide (150 mg/kg) 1 to 6 days before inoculation with viable Candida albicans showed an increased susceptibility to the challenge accompanied by a reduction in peripheral blood polymorphonuclear leukocytes and lymphocytes as well as in spleen cellularity. Several immunological in vitro functions also appeared to be dramatically depressed. Most of these hematological and functional parameters returned to control values by day 9 after cyclophosphamide administration, at a time when resistance to C. albicans infection appeared to be unchanged. However, when exposure to cyclophosphamide occurred 12 to 21 days before inoculation with the live yeast, enhanced resistance was observed with the majority of the animals surviving challenge. To gain some insight into the mechanisms underlying this late increase in resistance to C. albicans infection after cyclophosphamide administration, we analyzed a series of immunological functions, including the in vitro candidacidal activity of polymorphonuclear neutrophils and plastic-adherent and nonadherent spleen cells as well as the activity of natural killer cells and alloreactive T lymphocytes. The results show that a numerical rebound of blood polymorphonuclear neutrophils and the appearance of a highly candidacidal cell population in the spleen may be among the factors underlying the late increase in resistance to C. albicans after administration of cyclophosphamide. PMID:6339410

  14. Coptis chinensis and Myrobalan (Terminalia chebula) Can Synergistically Inhibit Inflammatory Response In Vitro and In Vivo

    PubMed Central

    Cui, Enhui; Zhi, Xiaoyan; Chen, Ying; Gao, Yuanyuan; Fan, Yunpeng; Zhang, Weimin; Ma, Wuren; Hou, Weifeng; Guo, Chao; Song, Xiaoping

    2014-01-01

    Objectives. To investigate the anti-inflammatory effect of Coptis chinensis plus myrobalan (CM) in vitro and in vivo. Methods. The inflammation in mouse peritoneal macrophages was induced by lipopolysaccharide (LPS). Animal models were established by using ear swelling and paw edema of mouse induced by xylene and formaldehyde, respectively. In vitro, cytotoxicity, the phagocytosis of macrophages, the levels of nitric oxide (NO), induced nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in cell supernatant were detected. In vivo, swelling rate and edema inhibitory rate of ear and paw were observed using CM-treated mice. Results. At 150–18.75 μg·mL−1, CM had no cytotoxicity and could significantly promote the growth and the phagocytosis of macrophages and inhibit the overproduction of NO, iNOS, TNF-α, and IL-6 in macrophages induced by LPS. In vivo, pretreatment with CM, the ear swelling, and paw edema of mice could be significantly inhibited in a dose-dependent manner, and the antiedema effect of CM at high dose was better than dexamethasone. Conclusion. Our results demonstrated that Coptis chinensis and myrobalan possessed synergistically anti-inflammatory activities in vitro and in vivo, which indicated that CM had therapeutic potential for the prevention and treatment of inflammation-mediated diseases. PMID:25587343

  15. Harmaline and hispidin from Peganum harmala and Inonotus hispidus with binding affinity to Candida rugosa lipase: In silico and in vitro studies.

    PubMed

    Benarous, Khedidja; Bombarda, Isabelle; Iriepa, Isabel; Moraleda, Ignacio; Gaetan, Herbette; Linani, Abderrahmane; Tahri, Djillali; Sebaa, Mohamed; Yousfi, Mohamed

    2015-10-01

    The inhibitory effect of phenolic compounds and alkaloids of Inonotus hispidus and Peganum harmala on Candida rugosa lipase was investigated, also, their antioxidant activities using DPPH, ABTS and phosphomolybdenum were studied in this paper. The phenolic extracts have shown a stronger antiradical activity than the alkaloids extracts. The enzymatic inhibition produced by these extracts is described here for the first time. The results have shown that the phenolic and the alkaloid extracts are good inhibitors of C. rugosa lipase. Thus, the inhibitor molecules (harmaline and hispidin) have been isolated from P. harmala and I. hispidus. Their structures were elucidated by (1)H NMR analysis. Molecular docking has been achieved using AutoDock Vina program to discuss the nature of interactions and the mechanism of inhibition. Therefore, these isolated molecules could be used in the treatment of candidiasis. PMID:26151548

  16. The in vitro biological effect of nerve growth factor is inhibited by synthetic peptides.

    PubMed Central

    Longo, F M; Vu, T K; Mobley, W C

    1990-01-01

    Nerve growth factor (NGF)1 is a neurotrophic polypeptide that acts via specific receptors to promote the survival and growth of neurons. To delineate the NGF domain(s) responsible for eliciting biological activity, we synthesized small peptides corresponding to three regions in NGF that are hydrophilic and highly conserved. Several peptides from mouse NGF region 26-40 inhibited the neurite-promoting effect of NGF on sensory neurons in vitro. Inhibition was sequence-specific and could be overcome by increasing the concentration of NGF. Moreover, peptide actions were specific for NGF-mediated events in that they failed to block the neurotrophic activity of ciliary neuronotrophic factor (CNTF) or phorbol 12-myristate 13-acetate (PMA). In spite of the inhibition of NGF activity, peptides did not affect the binding of radiolabeled NGF. These studies define one region of NGF that may be required for neurotrophic activity. Images PMID:2100197

  17. PAC-1 Activates Procaspase-3 in vitro through Relief of Zinc-Mediated Inhibition

    PubMed Central

    Peterson, Quinn P.; Goode, David R.; West, Diana C.; Ramsey, Kara N.; Lee, Joy; Hergenrother, Paul J.

    2009-01-01

    SUMMARY The direct induction of apoptosis has emerged as a powerful anti-cancer strategy, and small molecules that either inhibit or activate certain proteins in the apoptotic pathway have great potential as novel chemotherapeutic agents. Central to apoptosis is the activation of the zymogen procaspase-3 to caspase-3. Caspase-3 is the key “executioner” caspase, catalyzing the hydrolysis of a multitude of protein substrates within the cell. Interestingly, procaspase-3 levels are often elevated in cancer cells, suggesting a compound that directly stimulates the activation of procaspase-3 to caspase-3 could selectively induce apoptosis in cancer cells. We recently reported the discovery of a compound, PAC-1, which enhances procaspase-3 activity in vitro and induces apoptotic death in cancer cells in culture and in mouse xenograft models. Described herein is the mechanism by which PAC-1 activates procaspase-3 in vitro. We show that zinc inhibits the enzymatic activity of procaspase-3, and that PAC-1 strongly activates procaspase-3 in buffers that contain zinc. PAC-1 and zinc form a tight complex with one another, with a dissociation constant of approximately 42 nM. The combined data indicate that PAC-1 activates procaspase-3 in vitro by sequestering inhibitory zinc ions, thus allowing procaspase-3 to autoactivate itself to caspase-3. The small molecule mediated activation of procaspases has great therapeutic potential and thus this discovery of the in vitro mechanism of action of PAC-1 is critical to the development and optimization of other procaspase-activating compounds. PMID:19281821

  18. Milk Thistle Extract and Silymarin Inhibit Lipopolysaccharide Induced Lamellar Separation of Hoof Explants in Vitro

    PubMed Central

    Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

    2014-01-01

    The pathogenesis of laminitis is not completely identified and the role of endotoxins (lipopolysaccharides, LPS) in this process remains unclear. Phytogenic substances, like milk thistle (MT) and silymarin, are known for their anti-inflammatory and antioxidant properties and might therefore have the potential to counteract endotoxin induced effects on the hoof lamellar tissue. The aim of our study was to investigate the influence of endotoxins on lamellar tissue integrity and to test if MT and silymarin are capable of inhibiting LPS-induced effects in an in vitro/ex vivo model. In preliminary tests, LPS neutralization efficiency of these phytogenics was determined in an in vitro neutralization assay. Furthermore, tissue explants gained from hooves of slaughter horses were tested for lamellar separation after incubation with different concentrations of LPS. By combined incubation of explants with LPS and either Polymyxin B (PMB; positive control), MT or silymarin, the influence of these substances on LPS-induced effects was assessed. In the in vitro neutralization assay, MT and silymarin reduced LPS concentrations by 64% and 75%, respectively, in comparison PMB reduced 98% of the LPS concentration. In hoof explants, LPS led to a concentration dependent separation. Accordantly, separation force was significantly decreased by 10 µg/mL LPS. PMB, MT and silymarin could significantly improve tissue integrity of explants incubated with 10 µg/mL LPS. This study showed that LPS had a negative influence on the structure of hoof explants in vitro. MT and silymarin reduced endotoxin activity and inhibited LPS-induced effects on the lamellar tissue. Hence, MT and silymarin might be used to support the prevention of laminitis and should be further evaluated for this application. PMID:25290524

  19. Milk thistle extract and silymarin inhibit lipopolysaccharide induced lamellar separation of hoof explants in vitro.

    PubMed

    Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

    2014-10-01

    The pathogenesis of laminitis is not completely identified and the role of endotoxins (lipopolysaccharides, LPS) in this process remains unclear. Phytogenic substances, like milk thistle (MT) and silymarin, are known for their anti-inflammatory and antioxidant properties and might therefore have the potential to counteract endotoxin induced effects on the hoof lamellar tissue. The aim of our study was to investigate the influence of endotoxins on lamellar tissue integrity and to test if MT and silymarin are capable of inhibiting LPS-induced effects in an in vitro/ex vivo model. In preliminary tests, LPS neutralization efficiency of these phytogenics was determined in an in vitro neutralization assay. Furthermore, tissue explants gained from hooves of slaughter horses were tested for lamellar separation after incubation with different concentrations of LPS. By combined incubation of explants with LPS and either Polymyxin B (PMB; positive control), MT or silymarin, the influence of these substances on LPS-induced effects was assessed. In the in vitro neutralization assay, MT and silymarin reduced LPS concentrations by 64% and 75%, respectively, in comparison PMB reduced 98% of the LPS concentration. In hoof explants, LPS led to a concentration dependent separation. Accordantly, separation force was significantly decreased by 10 µg/mL LPS. PMB, MT and silymarin could significantly improve tissue integrity of explants incubated with 10 µg/mL LPS. This study showed that LPS had a negative influence on the structure of hoof explants in vitro. MT and silymarin reduced endotoxin activity and inhibited LPS-induced effects on the lamellar tissue. Hence, MT and silymarin might be used to support the prevention of laminitis and should be further evaluated for this application. PMID:25290524

  20. Synthesis and in vitro and in vivo inhibition potencies of highly relevant nerve agent surrogates.

    PubMed

    Meek, Edward C; Chambers, Howard W; Coban, Alper; Funck, Kristen E; Pringle, Ronald B; Ross, Matthew K; Chambers, Janice E

    2012-04-01

    Four nonvolatile nerve agent surrogates, 4-nitrophenyl ethyl dimethylphosphoramidate (NEDPA, a tabun surrogate), 4-nitrophenyl ethyl methylphosphonate (NEMP, a VX surrogate), and two sarin surrogates, phthalimidyl isopropyl methylphosphonate (PIMP) and 4-nitrophenyl isopropyl methylphosphonate (NIMP), were synthesized and tested as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. These surrogates were designed to phosphorylate cholinesterases with the same moiety as their respective nerve agents, making them highly relevant for the study of cholinesterase reactivators. Surrogates were characterized by liquid chromatography-mass spectrometry and nuclear magnetic resonance. NEMP, PIMP, and NIMP were potent inhibitors of rat brain, skeletal muscle, diaphragm, and serum AChE as well as human erythrocyte AChE and serum BuChE in vitro. PIMP was determined to degrade quickly in aqueous solution, making it useful for in vitro assays only, and NEDPA was not a potent inhibitor of AChE or BuChE in vitro; therefore, these two surrogates were not tested in subsequent in vivo studies. Sublethal dosages (yielding about 80% brain AChE inhibition) were determined for both the stable sarin surrogate, NIMP (0.325 mg/kg ip), and the VX surrogate, NEMP (0.4 mg/kg ip), in adult male rats. Time course studies indicated the time to peak brain AChE inhibition for both NIMP and NEMP to be 1 h postexposure. Both surrogates yielded severe cholinergic signs. These dosages did not require the addition of atropine to prevent lethality, and the rate of AChE aging was slow, making these surrogates useful for reactivation studies both in vitro and in vivo. The surrogates synthesized in this study are potent yet safer to test than nerve agents and are useful tools for initial screening of nerve agent oxime therapeutics. PMID:22247004

  1. β-Asarone, an active principle of Acorus calamus rhizome, inhibits morphogenesis, biofilm formation and ergosterol biosynthesis in Candida albicans.

    PubMed

    Rajput, Sandeep B; Karuppayil, S Mohan

    2013-01-15

    Anti-Candida potential of Acorus calamus rhizome and its active principle, β-asarone, was evaluated against the human fungal pathogen, Candida albicans. β-Asarone exhibited promising growth inhibitory activity at 0.5mg/ml and it was fungicidal at 8 mg/ml. Time dependant kill curve assay showed that MFC of β-asarone was highly toxic to C. albicans, killing 99.9% inoculum within 120 min of exposure. β-Asarone caused significant inhibition of C. albicans morphogenesis and biofilm development at sub-inhibitory concentrations. Our data indicate that the growth inhibitory activity of β-asarone might be through inhibition of ergosterol biosynthesis. Hemolytic assay showed that β-asarone is non-toxic, even at concentrations approaching MIC value. Our results suggest that β-asarone may be safe as a topical antifungal agent. PMID:23123225

  2. Time course of microbiologic outcome and gene expression in Candida albicans during and following in vitro and in vivo exposure to fluconazole.

    PubMed

    Lepak, A; Nett, J; Lincoln, L; Marchillo, K; Andes, D

    2006-04-01

    Pharmacodynamics (PD) considers the relationship between drug exposure and effect. The two factors that have been used to distinguish the PD behaviors of antimicrobials are the impact of concentration on the extent of organism killing and the duration of persistent microbiologic suppression (postantibiotic effect). The goals of these studies were (i) to examine the relationship between antimicrobial PD and gene expression and (ii) to gain insight into the mechanism of fluconazole effects persisting following exposure. Microarrays were used to estimate the transcriptional response of Candida albicans to a supra-MIC F exposure over time in vitro. Fluconazole at four times the MIC was added to a log-phase C. albicans culture, and cells were collected to determine viable growth and for microarray analyses. We identified differential expression of 18% of all genes for at least one of the time points. More genes were upregulated (n=1,053 [16%]) than downregulated (174 [3%]). Of genes with known function that were upregulated during exposure, most were related to plasma membrane/cell wall synthesis (18%), stress responses (7%), and metabolism (6%). The categories of downregulated genes during exposure included protein synthesis (15%), DNA synthesis/repair (7%), and transport (7%) genes. The majority of genes identified at the postexposure time points were from the protein (17%) and DNA (7%) synthesis categories. In subsequent studies, three genes (CDR1, CDR2, and ERG11) were examined in greater detail (more concentration and time points) following fluconazole exposure in vitro and in vivo. Expression levels from the in vitro and in vivo studies were congruent. CDR1 and CDR2 transcripts were reduced during in vitro fluconazole exposure and during supra-MIC exposure in vivo. However, in the postexposure period, the mRNA abundance of both pumps increased. ERG11 expression increased during exposure and fell in the postexposure period. The expression of the three genes

  3. Inhibition of Breast Cancer Cell Proliferation and In Vitro Tumorigenesis by a New Red Apple Cultivar

    PubMed Central

    Schiavano, Giuditta Fiorella; De Santi, Mauro; Brandi, Giorgio; Fanelli, Mirco; Bucchini, Anahi; Giamperi, Laura; Giomaro, Giovanna

    2015-01-01

    Purpose The aim of this study was to evaluate the antiproliferative activity in breast cancer cells and the inhibition of tumorigenesis in pre-neoplastic cells of a new apple cultivar with reddish pulp, called the Pelingo apple. Methods The antiproliferative activity was evaluated in MCF-7 and MDA-MB-231 human breast cancer cells. The inhibition of tumorigenesis was performed in JB6 promotion-sensitive (P+) cells. Results Results showed that Pelingo apple juice is characterized by a very high polyphenol content and strongly inhibited breast cancer cell proliferation. Its antiproliferative activity was found to be higher than the other five apple juices tested. Pelingo juice induced cell accumulation in the G2/M phase of the cell cycle and autophagy through overexpression of p21, inhibition of extracellular signal-regulated kinases 1/2 (ERK1/2) activity and an increase in lipidated microtubule-associated protein-1 light chain-3 beta (LC3B). Remarkably, Pelingo juice inhibited the 12-o-tetra-decanoyl-phorbol-13-acetate (TPA)-induced tumorigenesis of JB6 P+ cells, suppressing colony formation in semi-solid medium and TPA-induced ERK1/2 phosphorylation. Conclusions Our data indicate that the Pelingo apple is rich in food components that can markedly inhibit in vitro tumorigenesis and growth of human breast cancer cells and could provide natural bioactive non-nutrient compounds, with potential chemopreventive activity. PMID:26284516

  4. TQ inhibits hepatocellular carcinoma growth in vitro and in vivo via repression of Notch signaling

    PubMed Central

    Ke, Xiquan; Zhao, Yan; Lu, Xinlan; Wang, Zhe; Liu, Yuanyuan; Ren, Mudan; Lu, Guifang; Zhang, Dan; Sun, Zhenguo; Xu, Zhipeng; Song, Jee Hoon; Cheng, Yulan; Meltzer, Stephen J.; He, Shuixiang

    2015-01-01

    Thymoquinone (TQ) has been reported to possess anti-tumor activity in various types of cancer. However, its effects and molecular mechanism of action in hepatocellular carcinoma (HCC) are still not completely understood. We observed that TQ inhibited tumor cell growth in vitro, where treatment with TQ arrested the cell cycle in G1 by upregulating p21 and downregulating cyclinD1 and CDK2 expression; moreover, TQ induced apoptosis by decreasing expression of Bcl-2 and increasing expression of Bax. Simultaneously, TQ demonstrated a suppressive impact on the Notch pathway, where overexpression of NICD1 reversed the inhibitory effect of TQ on cell proliferation, thereby attenuating the repressive effects of TQ on the Notch pathway, cyclinD1, CDK2 and Bcl-2, and also diminishing upregulation of p21 and Bax. In a xenograft model, TQ inhibited HCC growth in nude mice; this inhibitory effect in vivo, as well as of HCC cell growth in vitro, was associated with a discernible decline in NICD1 and Bcl-2 levels and a dramatic rise in p21 expression. In conclusion, TQ inhibits HCC cell growth by inducing cell cycle arrest and apoptosis, achieving these effects by repression of the Notch signaling pathway, suggesting that TQ represents a potential preventive or therapeutic agent in HCC patients. PMID:26416455

  5. A natural small molecule voacangine inhibits angiogenesis both in vitro and in vivo

    SciTech Connect

    Kim, Yonghyo; Jung, Hye Jin; Kwon, Ho Jeong

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Voacangine exhibits potent anti-angiogenic activity both in vitro and in vivo. Black-Right-Pointing-Pointer Voacangine inhibits tumor-induced angiogenesis by suppressing HIF-1{alpha}. Black-Right-Pointing-Pointer Voacangine could be the basis for the development of novel anti-angiogenic agents. -- Abstract: Angiogenesis, the formation of new blood vessels from pre-existing ones, plays a critical role in normal and pathological phenotypes, including solid tumor growth and metastasis. Accordingly, the development of new anti-angiogenic agents is considered an efficient strategy for the treatment of cancer and other human diseases linked with angiogenesis. We have identified voacangine, isolated from Voacanga africana, as a novel anti-angiogenic agent. Voacangine inhibits the proliferation of HUVECs at an IC{sub 50} of 18 {mu}M with no cytotoxic effects. Voacangine significantly suppressed in vitro angiogenesis, such as VEGF-induced tube formation and chemoinvasion. Moreover, the compound inhibits in vivo angiogenesis in the chorioallantoic membrane at non-toxic doses. In addition, voacangine decreased the expression levels of hypoxia inducible factor-1{alpha} and its target gene, VEGF, in a dose-dependent manner. Taken together, these results suggest that the naturally occurring compound, voacangine, is a novel anti-angiogenic compound.

  6. In vitro assay of endotoxin by the inhibition of macrophage migration.

    PubMed

    Heilman, D H; Bast, R C

    1967-01-01

    A quantitative in vitro technique was used to compare the ability of different endotoxins to inhibit the migration of macrophages from explants of rabbit spleen cultured in a coagulated plasma medium. The order of potency was different from that observed in chick embryo assays, and in assays with mice, of the same endotoxins. In general, however, the sensitivity of the macrophage inhibition test was comparable to that of other bioassay methods. A highly purified endotoxin from Salmonella enteritidis (Ribi) in a concentration of 0.004 mug/ml regularly inhibited macrophage migration. The in vitro method was used to detect a progressive loss of biological activity in fractions obtained during acid hydrolysis of the purified endotoxin. The selective toxicity of very low concentrations of endotoxin for mammalian macrophages was important in estimating the degree of specificity of the reaction. The pattern of cellular response in explant cultures made it possible to differentiate endotoxic damage from the specific cytotoxic action of antigen associated with delayed hypersensitivity. PMID:5335889

  7. In Vitro Inhibition of Chick Embryo Lysyl Hydroxylase by Homogentisic Acid

    PubMed Central

    Murray, John C.; Lindberg, Kenneth A.; Pinnell, Sheldon R.

    1977-01-01

    Homogentisic acid inhibits the in vitro activity of chick embryo lysyl hydroxylase, a microsomal enzyme which catalyzes the transformation of certain lysyl residues in collagen to hydroxylysine. Chick embryo lysyl hydroxylase activity was measured as specific tritium release as tritium water from a [4,5-3H]lysine-labeled unhydroxylated collagen substrate prepared from chick calvaria. Kinetic studies revealed a linear, noncompetitive type of inhibition with respect to collagen substrate with a Ki of 120-180 μM. The inhibition by homogentisic acid was reversible in that enzyme activity could be restored after dialysis of preincubated mixtures of homogentisic acid with enzyme or substrate. The inhibition by homogentisic acid was competitive with respect to ascorbic acid, and the addition of reducing agents, such as ascorbic acid or 1,4-dithiothreitol, protected lysyl hydroxylase activity from homogentisic acid inhibition. In organ cultures of embryonic chick calvaria, biosynthesis of hydroxylysine-derived intermolecular collagen cross-links was inhibited in a dose-dependent manner by 0.5-5 mM homogentisic acid. Because homogentisic acid inhibits the formation of hydroxylysine in a cell-free assay and in organ cultures, this compound must pass into the cells of calvaria to inhibit intracellular hydroxylysine formation and subsequently to diminish the reducible intermolecular cross-links of the newly synthesized collagen. We propose that the inhibition of lysyl hydroxylase and the resulting hydroxylsine-deficient, structurally modified collagen may be clinically significant in the defective connective tissue found in alkaptonuric patients. PMID:405402

  8. Combined Application of Essential Oil Compounds and Bacteriophage to Inhibit Growth of Staphylococcus aureus In Vitro.

    PubMed

    Ghosh, Anisha; Ricke, Steven C; Almeida, Giselle; Gibson, Kristen E

    2016-04-01

    Staphylococcus aureus is considered an important human pathogen. This study aimed to investigate the combination of essential oil compounds (EOCs) and bacteriophage as alternative antimicrobials to control S. aureus in vitro. Here, four EOCs (alpha-pinene, 3-carene, (+)-limonene, (1S)-(-)-β-pinene) were evaluated by disc diffusion assay (DDA) and growth inhibition assay (GIA) to determine inhibitory effects against five strains of S. aureus. Phage adsorption assays were performed with phage K up to 120 h at 6, 13, and 37 °C to determine lytic activity. Combinations of phage K and EOCs against S. aureus were also evaluated at 37 °C. Alpha-pinene exhibited significantly greater inhibition towards S. aureus strains when compared to other EOCs tested by the DDA. GIAs indicate that all S. aureus strains exhibited significantly reduced growth (P < 0.006) over a 48-h period when exposed to EOCs. Phage adsorption assays indicate that phage K has high lytic activity at 37 °C with at least a 1.5-log increase in the number of plaque-forming units (PFU) over 6 h when compared to 6 and 13 °C. S. aureus strains showed significantly reduced growth (P < 0.05) when treated with combined phage K and EOCs. Results from the combined effect of EOC and phage indicate that phage alone inhibits S. aureus in vitro at 37 °C as effectively as EOCs alone or in combination with phage with variability between strains. The results from DDA, GIA, and phage adsorption assays indicate that select EOCs and phage K can be used as antimicrobials against S. aureus in vitro with potential application in situ. PMID:26719188

  9. A tissue-engineered therapeutic device inhibits tumor growth in vitro and in vivo.

    PubMed

    Sun, Ming; Wang, Miao; Chen, Muwan; Dagnaes-Hansen, Frederik; Le, Dang Quang Svend; Baatrup, Anette; Horsman, Michael R; Kjems, Jørgen; Bünger, Cody Eric

    2015-05-01

    Bone metastasis is one of the leading causes of death in breast cancer patients. The current treatment is performed as a palliative therapy and the adverse side effects can compromise the patients' quality of life. In order to both effectively treat bone metastasis and avoid the limitation of current strategies, we have invented a drug eluting scaffold with clay matrix release doxorubicin (DESCLAYMR_DOX) to mechanically support the structure after resecting the metastatic tissue while also releasing the anticancer drug doxorubicin which supplements growth inhibition and elimination of the remaining tumor cells. We have previously demonstrated that this device has the capacity to regenerate the bone and provide sustained release of the anticancer drug in vitro. In this study, we focus on the ability of the device to inhibit cancer cell growth in vitro as well as in vivo. Drug-release kinetics was investigated and the cell viability test showed that the tumor inhibitory effect is sustained for up to 4weeks in vitro. Subcutaneous implantation of DESCLAYMR_DOX in athymic mice resulted in significant growth inhibition of human tumor xenografts of breast origin and decelerated multi-organ metastasis formation. Fluorescence images, visualizing doxorubicin, showed a sustained drug release from the DESCLAYMR device in vivo. Furthermore, local use of DESCLAYMR_DOX implantation reduced the incidence of doxorubicin's cardio-toxicity. These results suggest that DESCLAYMR_DOX can be used in reconstructive surgery to support the structure after bone tumor resection and facilitate a sustained release of anticancer drugs in order to prevent tumor recurrence. PMID:25686557

  10. Fibroblast contraction of collagen lattices in vitro: inhibition by chronic inflammatory cell mediators.

    PubMed

    Ehrlich, H P; Wyler, D J

    1983-09-01

    Fibroblast-populated collagen lattices (FPCL), prepared in petri dishes with serum-containing culture medium and incubated at 37 degrees C, undergo progressive and symmetric contraction (reduction in size) over a period of days. The in vitro contraction process requires viable cells with intact cytoskeletal elements, is associated with cell elongation, and is believed to represent a fibroblast function which also occurs in vivo during wound healing and tissue fibrosis. We report that soluble mediators elaborated by chronic inflammatory cells cultured in vitro, when added to FPCL, inhibit lattice contraction. Granulomas, isolated from the liver of Schistosoma mansoni-infected mice, secrete a factor(s) with an estimated molecular weight between 13,700 and 43,000 daltons (gel filtration: Sephadex G-200) and pI = 6 (preparative isoelectrofocusing in granular gel) which inhibits lattice contraction but is not toxic to fibroblasts. Supernatants (cell-free conditioned culture medium) of cultured macrophages isolated from these granulomas also contain this activity. The contraction inhibitory activity present in granuloma culture supernatants is abrogated by the addition of indomethacin to the lattices, while the addition of prostaglandin E2 (PGE2) alone to lattices inhibits contraction. Furthermore, culture supernatants interfere with fibroblast elongation in lattices. We propose that the ability of fibroblasts to contract collagen lattices in vitro and a fibrotic mass in vivo may be regulated by soluble products of chronic inflammatory cells, including macrophages. This process may be mediated by fibroblast-derived prostaglandins which alter cytoskeletal functions and has implications for understanding regulation of tissue fibrogenesis in a variety of diseases. PMID:6885932

  11. [In vitro antimicrobial, antiadherent and antifungal activity of Brazilian medicinal plants on oral biofilm microorganisms and strains of the genus Candida].

    PubMed

    Alves, Pollianna Muniz; Queiroz, Lélia Maria Guedes; Pereira, Jozinete Vieira; Pereira, Maria do Socorro Vieira

    2009-01-01

    The antimicrobial, antifungal and antiadherent activity of aroeira-do-sertão, mallow and guava tree on oral biofilm microorganisms and oral candidiasis was evaluated in vitro. The extracts were shown to be effective in inhibiting the growth of bacteria of the oral biofilm and fungi of oral candidiasis, thus suggesting that these extracts can be used as alternative means of dental therapy. PMID:19448949

  12. Antioxidant and Preventive Effects of Extract from Nymphaea candida Flower on In Vitro Immunological Liver Injury of Rat Primary Hepatocyte Cultures

    PubMed Central

    Zhao, Jun; Liu, Tao; Ma, Long; Yan, Ming; Gu, Zhengyi; Huang, Yi; Xu, Fang; Zhao, Yu

    2011-01-01

    Nymphaea candida is traditional Uighur medicine that is commonly used to treat head pains, cough, hepatitis and hypertension in Xinjiang of China. In this article, the extract of N. candida was measured for antioxidant activity, using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging assay and reducing power determination, and compared with those of the positive controls of butylated hydroxytoluene (BHT) and gallic acid (GA). The active extract was further purified by liquid-liquid partition to afford four fractions, of which the ethyl acetate-soluble (EA) fraction (NCE) exhibited the strongest antioxidant capacity with IC50 value of 12.6 μg/mL for DPPH. Thirteen phenolic compounds were isolated from this fraction, and they all showed significant antioxidant activities in DPPH model system. Furthermore, NCE showed potent antioxidant capacity with IC50 value of 59.32 μg/mL, 24.48 μg/mL and 86.85 μg/mL, for O2−, ·OH and H2O2 radicals, respectively. Moreover, NCE on BCG plus LPS-induced immunological liver injury was evaluated using primary cultured rat hepatocytes. NCE produced significant hepatoprotective effects as evidenced by decreased supernatant enzyme activities (AST—aspartate transaminase, P <  .01; ALT—alanine transferase, P <  .01) and nitric oxide (NO, P <  .01) production. These results revealed the in vitro antioxidant and hepatoprotective activities of NCE against immunological liver injury. Further investigations are necessary to verify these activities in vivo. PMID:19196740

  13. Comparison of Antimicrobial Activity of Chlorhexidine, Coconut Oil, Probiotics, and Ketoconazole on Candida albicans Isolated in Children with Early Childhood Caries: An In Vitro Study

    PubMed Central

    Ahmed Bijapur, Gufran; Kottayi, Soni; Jose, Deepak

    2016-01-01

    Background. Early childhood caries (ECC) is associated with early colonisation and high levels of cariogenic microorganisms. With C. albicans being one of those, there is a need to determine the effectiveness of various chemotherapeutic agents against it. The study is aimed at isolating Candida species in children with ECC and at studying the antifungal effect of coconut oil, probiotics, Lactobacillus, and 0.2% chlorhexidine on C. albicans in comparison with ketoconazole. Materials and Methods. Samples were collected using sterile cotton swabs, swabbed on the tooth surfaces from children with ECC of 3 to 6 yrs and streaked on Sabouraud dextrose agar (HI Media) plates and incubated in a 5% CO2 enriched atmosphere at 37°C for 24 hours. Candida was isolated and its susceptibility to probiotics, chlorhexidine, ketoconazole, and coconut oil was determined using Disc Diffusion method. Results. The mean zone of inhibition for chlorhexidine was 21.8 mm, whereas for coconut oil it was 16.8 mm, for probiotics it was 13.5 mm, and for ketoconazole it was 22.3 mm. The difference between the groups was not statistically significant (Chi-square value 7.42, P value 0.06). Conclusion. Chlorhexidine and coconut oil have shown significant antifungal activity which is comparable with ketoconazole. PMID:27051559

  14. Comparison of Antimicrobial Activity of Chlorhexidine, Coconut Oil, Probiotics, and Ketoconazole on Candida albicans Isolated in Children with Early Childhood Caries: An In Vitro Study.

    PubMed

    Shino, Beena; Peedikayil, Faizal C; Jaiprakash, Shyamala R; Ahmed Bijapur, Gufran; Kottayi, Soni; Jose, Deepak

    2016-01-01

    Background. Early childhood caries (ECC) is associated with early colonisation and high levels of cariogenic microorganisms. With C. albicans being one of those, there is a need to determine the effectiveness of various chemotherapeutic agents against it. The study is aimed at isolating Candida species in children with ECC and at studying the antifungal effect of coconut oil, probiotics, Lactobacillus, and 0.2% chlorhexidine on C. albicans in comparison with ketoconazole. Materials and Methods. Samples were collected using sterile cotton swabs, swabbed on the tooth surfaces from children with ECC of 3 to 6 yrs and streaked on Sabouraud dextrose agar (HI Media) plates and incubated in a 5% CO2 enriched atmosphere at 37°C for 24 hours. Candida was isolated and its susceptibility to probiotics, chlorhexidine, ketoconazole, and coconut oil was determined using Disc Diffusion method. Results. The mean zone of inhibition for chlorhexidine was 21.8 mm, whereas for coconut oil it was 16.8 mm, for probiotics it was 13.5 mm, and for ketoconazole it was 22.3 mm. The difference between the groups was not statistically significant (Chi-square value 7.42, P value 0.06). Conclusion. Chlorhexidine and coconut oil have shown significant antifungal activity which is comparable with ketoconazole. PMID:27051559

  15. Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro.

    PubMed

    Mahalingam, Sharada; Gao, Liying; Gonnering, Marni; Helferich, William; Flaws, Jodi A

    2016-03-15

    Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral follicles isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, and 100 μM) for 48 and 96 h. Every 24h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles. PMID:26876617

  16. 5-azacytidine and 5-azadeoxycytidine inhibit human immunodeficiency virus type 1 replication in vitro.

    PubMed Central

    Bouchard, J; Walker, M C; Leclerc, J M; Lapointe, N; Beaulieu, R; Thibodeau, L

    1990-01-01

    Chemotherapeutic agents which affect the integration, stability, or inducibility of the human immunodeficiency virus (HIV) provirus would have considerable value in treating acquired immunodeficiency syndrome. Two nucleoside analogs of cytosine, 5-azacytidine and 5-azadeoxycytidine, which seem to have such value because of their capabilities to affect both the stability and the methylation patterns of the nucleic acids into which they are incorporated, were tested for their ability to inhibit the replication of HIV type 1 (HIV-1) in human CEM T cells in vitro. 5-Azadeoxycytidine (1 microM) completely inhibited HIV replication in CEM cells, by the criteria of reduced viral antigen expression and decreased supernatant reverse transcriptase activity, with little toxicity for the treated cells. 5-azacytidine (1 microM) also inhibited HIV replication, but less effectively. When added 2 or more h after CEM cells were infected with HIV-1, both 5-azacytosine derivatives were less effective than they were when added at the time of infection. Even 2 h of exposure to 5-azadeoxycytidine was sufficient for inhibition of HIV replication. Although long exposure to either analog at concentrations of 1 microM would result in pronounced cellular cytotoxicity, the the fact that short exposures to the same dose of drug inhibit HIV replication but are not toxic for the cells implies that cellular toxicity itself is not an important mechanism of the antiviral action of the analogs. PMID:1691617

  17. Antibiotic drug tigecycline reduces neuroblastoma cells proliferation by inhibiting Akt activation in vitro and in vivo.

    PubMed

    Zhong, Xiaoxia; Zhao, Erhu; Tang, Chunling; Zhang, Weibo; Tan, Juan; Dong, Zhen; Ding, Han-Fei; Cui, Hongjuan

    2016-06-01

    As the first member of glycylcycline bacteriostatic agents, tigecycline is approved as a novel expanded-spectrum antibiotic, which is clinically available. However, accumulating evidence indicated that tigecycline was provided with the potential application in cancer therapy. In this paper, tigecycline was shown to exert an anti-proliferative effect on neuroblastoma cell lines. Furthermore, it was found that tigecycline induced G1-phase cell cycle arrest instead of apoptosis by means of Akt pathway inhibition. In neuroblastoma cell lines, the Akt activator insulin-like growth factor-1 (hereafter referred to as IGF-1) reversed tigecycline-induced cell cycle arrest. Besides, tigecycline inhibited colony formation and suppressed neuroblastoma cells xenograft formation and growth. After tigecycline treatment in vivo, the Akt pathway inhibition was confirmed as well. Collectively, our data provided strong evidences that tigecycline inhibited neuroblastoma cells growth and proliferation through the Akt pathway inhibition in vitro and in vivo. In addition, these results were supported by previous studies concerning the application of tigecycline in human tumors treatment, suggesting that tigecycline might act as a potential candidate agent for neuroblastoma treatment. PMID:26687647

  18. A natural small molecule voacangine inhibits angiogenesis both in vitro and in vivo.

    PubMed

    Kim, Yonghyo; Jung, Hye Jin; Kwon, Ho Jeong

    2012-01-01

    Angiogenesis, the formation of new blood vessels from pre-existing ones, plays a critical role in normal and pathological phenotypes, including solid tumor growth and metastasis. Accordingly, the development of new anti-angiogenic agents is considered an efficient strategy for the treatment of cancer and other human diseases linked with angiogenesis. We have identified voacangine, isolated from Voacanga africana, as a novel anti-angiogenic agent. Voacangine inhibits the proliferation of HUVECs at an IC(50) of 18 μM with no cytotoxic effects. Voacangine significantly suppressed in vitro angiogenesis, such as VEGF-induced tube formation and chemoinvasion. Moreover, the compound inhibits in vivo angiogenesis in the chorioallantoic membrane at non-toxic doses. In addition, voacangine decreased the expression levels of hypoxia inducible factor-1α and its target gene, VEGF, in a dose-dependent manner. Taken together, these results suggest that the naturally occurring compound, voacangine, is a novel anti-angiogenic compound. PMID:22155252

  19. Convallatoxin, a Dual Inducer of Autophagy and Apoptosis, Inhibits Angiogenesis In Vitro and In Vivo

    PubMed Central

    Yang, Seung Ya; Kim, Nam Hee; Cho, Yoon Sun; Lee, Hukeun; Kwon, Ho Jeong

    2014-01-01

    Autophagy and apoptosis are important processes that control cellular homeostasis and have been highlighted as promising targets for novel cancer therapies. Here, we identified convallatoxin (CNT), isolated from Antiaris toxicaria, as a dual inducer of autophagy and apoptosis. CNT exerts cytotoxic effects on a number of cancer and normal cell lines and induces apoptosis by increasing caspase-3 and poly ADP ribose polymerase (PARP) cleavage. Moreover, dose- and time-dependent autophagic activity was detected in CNT-treated cells, and mammalian target of rapamycin (mTOR)/p70S6K signal pathway inhibition was observed. Notably, CNT inhibits human umbilical vein endothelial cell (HUVEC) growth and exerts anti-angiogenic activity in vitro and in vivo. Collectively, these results demonstrate that the naturally occurring compound, CNT, is a novel anti-angiogenic compound via dual inducing of autophagy and apoptosis. PMID:24663328

  20. Artemisinin inhibits in vitro and in vivo invasion and metastasis of human hepatocellular carcinoma cells.

    PubMed

    Weifeng, Tan; Feng, Shen; Xiangji, Luo; Changqing, Su; Zhiquan, Qiu; Huazhong, Zeng; Peining, Yan; Yong, Yu; Mengchao, Wu; Xiaoqing, Jiang; Wan-Yee, Lau

    2011-01-15

    Artemisinin (ART) is isolated from the medicinal plant Artemisia annua L. To determine its effects on the invasion and metastasis of tumors, the human hepatocellular carcinoma (HCC) cell lines HepG2 and SMMC-7721 were treated with different concentrations of ART. Starting at 12.5μM, ART had inhibitory effects in migration and invasion assays that increased at higher concentrations. The inhibitory effect also became stronger with time, from 24 to 72h. ART significantly inhibited the in vivo metastatic abilities of the HepG2 HCC cell line. ART inhibited the invasion and metastasis of HCC cells both in vitro and in vivo by reducing the level of the MMP2 metalloproteinase, and by inducing the TIMP2 protein. ART activated Cdc42, which enhanced E-cadherin activity, resulting in greater cell-cell adhesion, and significantly reduced metastasis. PMID:20739158

  1. Positions and Numbers of FKS Mutations in Candida albicans Selectively Influence In Vitro and In Vivo Susceptibilities to Echinocandin Treatment

    PubMed Central

    Tscherner, M.; Schaller, M.; Kuchler, K.; Mair, C.; Sartori, B.; Istel, F.; Arendrup, M. C.; Lass-Flörl, C.

    2014-01-01

    Candidemia is the fourth most common kind of microbial bloodstream infection, with Candida albicans being the most common causative species. Echinocandins are employed as the first-line treatment for invasive candidiasis until the fungal species is determined and confirmed by clinical diagnosis. Echinocandins block the FKS glucan synthases responsible for embedding β-(1,3)-d-glucan in the cell wall. The increasing use of these drugs has led to the emergence of antifungal resistance, and elevated MICs have been associated with single-residue substitutions in specific hot spot regions of FKS1 and FKS2. Here, we show for the first time the caspofungin-mediated in vivo selection of a double mutation within one allele of the FKS1 hot spot 1 in a clinical isolate. We created a set of isogenic mutants and used a hematogenous murine model to evaluate the in vivo outcomes of echinocandin treatment. Heterozygous and homozygous double mutations significantly enhance the in vivo resistance of C. albicans compared with the resistance seen with heterozygous single mutations. The various FKS1 hot spot mutations differ in the degree of their MIC increase, substance-dependent in vivo response, and impact on virulence. Our results demonstrate that echinocandin EUCAST breakpoint definitions correlate with the in vivo response when a standard dosing regimen is used but cannot predict the in vivo response after a dose escalation. Moreover, patients colonized by a C. albicans strain with multiple mutations in FKS1 have a higher risk for therapeutic failure. PMID:24733467

  2. Effects of neutrophils and in vitro oxidants on survival and phenotypic switching of Candida albicans WO-1.

    PubMed Central

    Kolotila, M P; Diamond, R D

    1990-01-01

    The relationship to pathogenesis of the spontaneous phenotypic switching of Candida albicans is uncertain. Since neutrophils are critical in containment of disseminated candidiasis, we used these cells and some of their potentially microbicidal oxidative products to define effects on a C. albicans strain (WO-1) that exhibits characteristic, easily recognized switching between the white and opaque phenotypes. Blastoconidia of the opaque phenotypes were more susceptible than those of the white to killing by either intact neutrophils or cell-free oxidants, including reagent hydrogen peroxide or the myeloperoxidase-H2O2-Cl- system. Paralleling these findings, opaque blastoconidia were 2.8- to 3.6-fold more potent stimuli of neutrophil superoxide generation than were the white cells. In addition, both neutrophils and oxidants (reagent H2O2 or hypochlorous acid as well as the myeloperoxidase-H2O2-Cl- system) induced unidirectional increases in spontaneous rates of switching from white to opaque phenotypes. Differences in expression of C. albicans phenotypes therefore may determine relative susceptibility to neutrophil fungicidal mechanisms, and neutrophils themselves appear to be capable of selectively augmenting the switching process. PMID:2157666

  3. In vitro fluconazole susceptibility of 1,903 clinical isolates of Candida albicans and the identification of ERG11 mutations.

    PubMed

    Ying, Ying; Zhao, Yingjie; Hu, Xuefei; Cai, Zhenyu; Liu, Xin; Jin, Guilin; Zhang, Jieyu; Zhang, Jingyi; Liu, Jinhui; Huang, Xiaotian

    2013-08-01

    Abstract Fluconazole resistance of Candida albicans has been reported to be the result of one or more specific point mutations in ERG11 gene. In this study, we amplified and sequenced the entire ERG11 coding sequence of 72 isolates of C. albicans to search for possible mutations. Twenty-seven silent mutations and 14 missense mutations were identified. While the mutations K342R and V437I were found as single-amino-acid changes in Erg11p, other mutations were detected simultaneously in individual isolates. Several different clinical isolates had the same pattern of multiple amino acid alternations: (1) A114S with Y257H was identified in 11 resistant and 3 susceptible dose-dependent isolates without any other silent mutation and may be associated with resistance; (2) Y132H combined with G450E was identified in two fluconazole-resistant isolates and is known to contribute to resistance; and (3) the coexistence of D116E, K128T, Y132H, and G465S was first described in five reduced-susceptibility isolates, but the correlation of this pattern with resistance is still uncertain. These data indicate that multiple amino acid substitutions in Erg11p were found frequently in clinical isolates and may be associated with fluconazole resistance. PMID:23484590

  4. β-catenin knockdown inhibits the proliferation of human glioma cells in vitro and in vivo

    PubMed Central

    WANG, ZHONG; CHEN, QIANXUE

    2016-01-01

    β-catenin is a crucial oncogene that is capable of regulating cancer progression. The aim of the present study was to clarify whether β-catenin was associated with the proliferation and progress of glioma. In order to knockdown the expression of β-catenin in human U251 glioma cells, three pairs of small interfering (si)RNA were designed and synthesized and the most effective siRNA was selected and used for silencing the endogenous β-catenin, which was detected by western blot analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Proliferation was subsequently detected using a methylthiazolyl-tetrazolium bromide assay and the results demonstrated that knockdown of β-catenin significantly inhibited the proliferation of U251 cells in a time- and dose-dependent manner (P<0.01). Cell apoptosis rate was analyzed using flow cytometry and Annexin V-fluorescein isothiocyanate/propidium iodide staining demonstrated that β-catenin siRNA significantly increased the apoptosis of U251 cells (P<0.01). Furthermore, the results of an in vitro scratch assay demonstrated that β-catenin silencing suppressed the proliferation of U251 cells, as compared with the control group (P<0.01). In vivo, β-catenin expression levels in U251 cells were significantly inhibited (P<0.01) following β-catenin short hairpin (sh)RNA lentiviral-vector transfection, as detected by western blot analysis and RT-qPCR. Tumorigenicity experiments demonstrated that β-catenin inhibition significantly increased the survival rate of nude mice. The results of the present study demonstrated that knockdown of β-catenin expression significantly inhibited the progression of human glioma cancer cells, in vitro and in vivo; thus suggesting that β-catenin silencing may be a novel therapy for the treatment of human glioma. PMID:26998037

  5. Baicalein Inhibits Staphylococcus aureus Biofilm Formation and the Quorum Sensing System In Vitro

    PubMed Central

    Wang, Ke; Hou, Changchun; Cai, Shuangqi; Huang, Yingying; Du, Zhongye; Huang, Hong; Kong, Jinliang; Chen, Yiqiang

    2016-01-01

    Biofilm formed by Staphylococcus aureus significantly enhances antibiotic resistance by inhibiting the penetration of antibiotics, resulting in an increasingly serious situation. This study aimed to assess whether baicalein can prevent Staphylococcus aureus biofilm formation and whether it may have synergistic bactericidal effects with antibiotics in vitro. To do this, we used a clinically isolated strain of Staphylococcus aureus 17546 (t037) for biofilm formation. Virulence factors were detected following treatment with baicalein, and the molecular mechanism of its antibiofilm activity was studied. Plate counting, crystal violet staining, and fluorescence microscopy revealed that 32 μg/mL and 64 μg/mL baicalein clearly inhibited 3- and 7-day biofilm formation in vitro. Moreover, colony forming unit count, confocal laser scanning microscopy, and scanning electron microscopy showed that vancomycin (VCM) and baicalein generally enhanced destruction of biofilms, while VCM alone did not. Western blotting and real-time quantitative polymerase chain reaction analyses (RTQ-PCR) confirmed that baicalein treatment reduced staphylococcal enterotoxin A (SEA) and α-hemolysin (hla) levels. Most strikingly, real-time qualitative polymerase chain reaction data demonstrated that 32 μg/mL and 64 μg/mL baicalein downregulated the quorum-sensing system regulators agrA, RNAIII, and sarA, and gene expression of ica, but 16 μg/mL baicalein had no effect. In summary, baicalein inhibited Staphylococcus aureus biofilm formation, destroyed biofilms, increased the permeability of vancomycin, reduced the production of staphylococcal enterotoxin A and α-hemolysin, and inhibited the quorum sensing system. These results support baicalein as a novel drug candidate and an effective treatment strategy for Staphylococcus aureus biofilm-associated infections. PMID:27128436

  6. Unfractionated Heparin Promotes Osteoclast Formation in Vitro by Inhibiting Osteoprotegerin Activity

    PubMed Central

    Li, Binghan; Lu, Dan; Chen, Yuqing; Zhao, Minghui; Zuo, Li

    2016-01-01

    Heparin has been proven to enhance bone resorption and induce bone loss. Since osteoclasts play a pivotal role in bone resorption, the effect of heparin on osteoclastogenesis needs to be clarified. Since osteocytes are the key modulator during osteoclastogenesis, we evaluated heparin’s effect on osteoclastogenesis in vitro by co-culturing an osteocyte cell line (MLO-Y4) and pre-osteoclasts (RAW264.7). In this co-culture system, heparin enhanced osteoclastogenesis and osteoclastic bone resorption while having no influence on the production of RANKL (receptor activator of NFκB ligand), M-CSF (macrophage colony-stimulating factor), and OPG (osteoprotegerin), which are three main regulatory factors derived from osteocytes. According to previous studies, heparin could bind specifically to OPG and inhibit its activity, so we hypothesized that this might be a possible mechanism of heparin activity. To test this hypothesis, osteoclastogenesis was induced using recombinant RANKL or MLO-Y4 supernatant. We found that heparin has no effect on RANKL-induced osteoclastogenesis (contains no OPG). However, after incubation with OPG, the capacity of MLO-Y4 supernatant for supporting osteoclast formation was increased. This effect disappeared after OPG was neutralized and reappeared after OPG was replenished. These results strongly suggest that heparin promotes osteocyte-modulated osteoclastogenesis in vitro, at least partially, through inhibiting OPG activity. PMID:27110777

  7. Inhibition of adenovirus multiplication by inosine pranobex and interferon α in vitro

    PubMed Central

    Lasek, Witold; Janyst, Michał; Młynarczyk, Grażyna

    2016-01-01

    There are no specific antivirals designed for adenoviral infections. Due to many cases of adenovirus infections worldwide, epidemic nature of some types of adenoviruses, and growing number of patients with severe adenoviral infections resulting from dysfunction the immune system, the need for searching an effective and safe therapy is increasing. Inosine pranobex exerts antiviral effects which are both direct and secondary to immunomodulatory activity. In the present study we evaluated in vitro effect of inosine pranobex and interferon α (IFN-α) on replication of HAdV-2 and HAdV-5. The effectiveness of inosine pranobex under these conditions has not been previously reported. In conducted study we reported that inosine pranobex reduced the titer of infectious HAdV-2 and HAdV-5 in vitro. Higher concentrations of IP strongly inhibited multiplication of viruses. Combination of inosine pranobex and IFN-α display higher efficacy than either treatment alone and suggest that both agents may increase therapeutic effectiveness without augmenting toxic effects. Combination index calculations showed that inosine pranobex and INF-α synergistically inhibit HAdV-2 and HAdV-5 titers in A549 cells. PMID:26862302

  8. Terminalia bellirica Extract Inhibits Low-Density Lipoprotein Oxidation and Macrophage Inflammatory Response in Vitro

    PubMed Central

    Tanaka, Miori; Kishimoto, Yoshimi; Saita, Emi; Suzuki-Sugihara, Norie; Kamiya, Tomoyasu; Taguchi, Chie; Iida, Kaoruko; Kondo, Kazuo

    2016-01-01

    The deciduous tree Terminalia bellirica found in Southeast Asia is extensively used in traditional Indian Ayurvedic medicine for the treatment of hypertension, rheumatism, and diabetes. The anti-atherogenic effect of Terminalia bellirica fruit has not been fully elucidated. Here, we investigated the effect of Terminalia bellirica extract (TBE) on low-density lipoprotein (LDL) oxidation and inflammation in macrophages. TBE showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (EC50: 7.2 ± 1.2 μg/mL) and 15-lipoxygenase inhibitory activity. TBE also significantly inhibited free radical-induced LDL oxidation compared to the solvent control in vitro. In THP-1 macrophages, TBE treatment resulted in significant decreases of the mRNA expression of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and lectin-like oxidized LDL receptor-1 (LOX-1). TBE also reduced matrix metalloproteinase (MMP)-9 secretion and intracellular reactive oxygen species (ROS) production in THP-1 macrophages. These results show that TBE has the inhibitory effects on LDL oxidation and macrophage inflammatory response in vitro, suggesting that its in vivo use might inhibit atherosclerosis plaque progression. PMID:27314393

  9. Terminalia bellirica Extract Inhibits Low-Density Lipoprotein Oxidation and Macrophage Inflammatory Response in Vitro.

    PubMed

    Tanaka, Miori; Kishimoto, Yoshimi; Saita, Emi; Suzuki-Sugihara, Norie; Kamiya, Tomoyasu; Taguchi, Chie; Iida, Kaoruko; Kondo, Kazuo

    2016-01-01

    The deciduous tree Terminalia bellirica found in Southeast Asia is extensively used in traditional Indian Ayurvedic medicine for the treatment of hypertension, rheumatism, and diabetes. The anti-atherogenic effect of Terminalia bellirica fruit has not been fully elucidated. Here, we investigated the effect of Terminalia bellirica extract (TBE) on low-density lipoprotein (LDL) oxidation and inflammation in macrophages. TBE showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (EC50: 7.2 ± 1.2 μg/mL) and 15-lipoxygenase inhibitory activity. TBE also significantly inhibited free radical-induced LDL oxidation compared to the solvent control in vitro. In THP-1 macrophages, TBE treatment resulted in significant decreases of the mRNA expression of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and lectin-like oxidized LDL receptor-1 (LOX-1). TBE also reduced matrix metalloproteinase (MMP)-9 secretion and intracellular reactive oxygen species (ROS) production in THP-1 macrophages. These results show that TBE has the inhibitory effects on LDL oxidation and macrophage inflammatory response in vitro, suggesting that its in vivo use might inhibit atherosclerosis plaque progression. PMID:27314393

  10. Unfractionated Heparin Promotes Osteoclast Formation in Vitro by Inhibiting Osteoprotegerin Activity.

    PubMed

    Li, Binghan; Lu, Dan; Chen, Yuqing; Zhao, Minghui; Zuo, Li

    2016-01-01

    Heparin has been proven to enhance bone resorption and induce bone loss. Since osteoclasts play a pivotal role in bone resorption, the effect of heparin on osteoclastogenesis needs to be clarified. Since osteocytes are the key modulator during osteoclastogenesis, we evaluated heparin's effect on osteoclastogenesis in vitro by co-culturing an osteocyte cell line (MLO-Y4) and pre-osteoclasts (RAW264.7). In this co-culture system, heparin enhanced osteoclastogenesis and osteoclastic bone resorption while having no influence on the production of RANKL (receptor activator of NFκB ligand), M-CSF (macrophage colony-stimulating factor), and OPG (osteoprotegerin), which are three main regulatory factors derived from osteocytes. According to previous studies, heparin could bind specifically to OPG and inhibit its activity, so we hypothesized that this might be a possible mechanism of heparin activity. To test this hypothesis, osteoclastogenesis was induced using recombinant RANKL or MLO-Y4 supernatant. We found that heparin has no effect on RANKL-induced osteoclastogenesis (contains no OPG). However, after incubation with OPG, the capacity of MLO-Y4 supernatant for supporting osteoclast formation was increased. This effect disappeared after OPG was neutralized and reappeared after OPG was replenished. These results strongly suggest that heparin promotes osteocyte-modulated osteoclastogenesis in vitro, at least partially, through inhibiting OPG activity. PMID:27110777

  11. Linarin Inhibits the Acetylcholinesterase Activity In-vitro and Ex-vivo.

    PubMed

    Feng, Xinchi; Wang, Xin; Liu, Youping; Di, Xin

    2015-01-01

    Linarin is a flavone glycoside in the plants Flos chrysanthemi indici, Buddleja officinalis, Cirsium setosum, Mentha arvensis and Buddleja davidii, and has been reported to possess analgesic, antipyretic, anti-inflammatory and neuroprotective activities. In this paper, linarin was investigated for its AChE inhibitory potential both in-vitro and ex-vivo. Ellman's colorimetric method was used for the determination of AChE inhibitory activity in mouse brain. In-vitro assays revealed that linarin inhibited AChE activity with an IC50 of 3.801 ± 1.149 μM. Ex-vivo study showed that the AChE activity was significantly reduced in both the cortex and hippocampus of mice treated intraperitoneally with various doses of linarin (35, 70 and 140 mg/Kg). The inhibition effects produced by high dose of linarin were the same as that obtained after huperzine A treatment (0.5 mg/Kg). Molecular docking study revealed that both 4'-methoxyl group and 7-O-sugar moiety of linarin played important roles in ligand-receptor binding and thus they are mainly responsible for AChE inhibitory activity. In view of its potent AChE inhibitory activity, linarin may be a promising therapeutic agent for the treatment of some diseases associated with AChE, such as glaucoma, myasthenia gravis, gastric motility and Alzheimer's disease. PMID:26330885

  12. Linarin Inhibits the Acetylcholinesterase Activity In-vitro and Ex-vivo

    PubMed Central

    Feng, Xinchi; Wang, Xin; Liu, Youping; Di, Xin

    2015-01-01

    Linarin is a flavone glycoside in the plants Flos chrysanthemi indici, Buddleja officinalis, Cirsium setosum, Mentha arvensis and Buddleja davidii, and has been reported to possess analgesic, antipyretic, anti-inflammatory and neuroprotective activities. In this paper, linarin was investigated for its AChE inhibitory potential both in-vitro and ex-vivo. Ellman’s colorimetric method was used for the determination of AChE inhibitory activity in mouse brain. In-vitro assays revealed that linarin inhibited AChE activity with an IC50 of 3.801 ± 1.149 μM. Ex-vivo study showed that the AChE activity was significantly reduced in both the cortex and hippocampus of mice treated intraperitoneally with various doses of linarin (35, 70 and 140 mg/Kg). The inhibition effects produced by high dose of linarin were the same as that obtained after huperzine A treatment (0.5 mg/Kg). Molecular docking study revealed that both 4’-methoxyl group and 7-O-sugar moiety of linarin played important roles in ligand-receptor binding and thus they are mainly responsible for AChE inhibitory activity. In view of its potent AChE inhibitory activity, linarin may be a promising therapeutic agent for the treatment of some diseases associated with AChE, such as glaucoma, myasthenia gravis, gastric motility and Alzheimer’s disease. PMID:26330885

  13. A cortical astrocyte subpopulation inhibits axon growth in vitro and in vivo.

    PubMed

    Liu, Rui; Wang, Zhe; Gou, Lin; Xu, Hanpeng

    2015-08-01

    Astrocytes are the most heterogeneous and predominant glial cell type in the central nervous system. However, the functional significance of this heterogeneity remains to be elucidated. Following injury, damaged astrocytes inhibit axonal regeneration in vivo and in vitro. Cultured primary astrocytes are commonly considered good supportive substrates for neuron attachment and axon regeneration. However, it is not known whether different populations of cells in the heterogeneous astrocyte culture affect neuron behavior in the same way. In the present study, the effect of astrocyte heterogeneity on neuronal attachment and neurite outgrowth was examined using an in vitro and in vivo coculture system. In vitro, neonatal cortical astrocytes were co-cultured with purified dorsal root ganglia (DRG) neurons and astrocyte growth morphology, neuron attachment and neurite growth were evaluated. The results demonstrated that the heterogeneous astrocyte cells showed two different types of growth pattern, typical and atypical. Typical astrocytes were supportive to neuron attachment and neurite growth, which was consistent with previous studies, whereas atypical astrocytes inhibited neuron attachment and neurite growth. These inhibitory astrocytes exhibited a special growth pattern with various shapes and sizes, a high cell density, few oligodendrocytes on the top layer and occupied a smaller growth area compared with typical astrocytes. Neurites extended freely on typical supportive astrocyte populations, however, moved away when they reached atypical astrocyte growth pattern. Neurons growing on the atypical astrocyte pattern demonstrated minimal neurite outgrowth and these neurites had a dystrophic appearance, however, neuronal survival was unaffected. Immunocytochemistry studies demonstrated that these atypical inhibitory astrocytes were glial fibrillary acidic protein (GFAP) positive cells. The existence of inhibitory astrocyte subpopulations in normal astrocytes reflects the

  14. Inhibition of the adenine nucleotide translocator by N-acetyl perfluorooctane sulfonamides in vitro

    SciTech Connect

    O'Brien, Timothy M. Oliveira, Paulo J.; Wallace, Kendall B.

    2008-03-01

    N-alkyl perfluorooctane sulfonamides have been widely used as surfactants on fabrics and papers, fire retardants, and anti-corrosion agents, among many other commercial applications. The global distribution and environmental persistence of these compounds has generated considerable interest regarding potential toxic effects. We have previously reported that perfluorooctanesulfonamidoacetate (FOSAA) and N-ethylperfluorooctanesulfonamidoacetate (N-EtFOSAA) induce the mitochondrial permeability transition (MPT) in vitro. In this study we tested the hypothesis that FOSAA and N-EtFOSAA interact with the adenine nucleotide translocator (ANT) resulting in a functional inhibition of the translocator and induction of the MPT. Respiration and membrane potential of freshly isolated liver mitochondria from Sprague-Dawley rats were measured using an oxygen electrode and a tetraphenylphosphonium-selective (TPP{sup +}) electrode, respectively. Mitochondrial swelling was measured spectrophotometrically. The ANT ligands bongkregkic acid (BKA) and carboxyatractyloside (cATR) inhibited uncoupling of mitochondrial respiration caused by 10 {mu}M N-EtFOSAA, 40 {mu}M FOSAA, and the positive control 8 {mu}M oleic acid. ADP-stimulated respiration and depolarization of mitochondrial membrane potential were inhibited by cATR, FOSAA, N-EtFOSAA, and oleic acid, but not by FCCP. BKA inhibited calcium-dependent mitochondrial swelling induced by FOSAA, N-EtFOSAA, and oleic acid. Seventy-five micromolar ADP also inhibited swelling induced by the test compounds, but cATR induced swelling was not inhibited by ADP. Results of this investigation indicate that N-acetyl perfluorooctane sulfonamides interact directly with the ANT to inhibit ADP translocation and induce the MPT, one or both of which may account for the metabolic dysfunction observed in vivo.

  15. Production of mouse monoclonal antibodies which inhibit in vitro adherence of Entamoeba histolytica trophozoites.

    PubMed Central

    Ravdin, J I; Petri, W A; Murphy, C F; Smith, R D

    1986-01-01

    Adherence by axenic Entamoeba histolytica trophozoites to mammalian cells is mediated by an N-acetylgalactosamine (GalNAc)-inhibitable adhesin on the surface of the parasite. We isolated 35 hybridoma cell lines producing antibodies to E. histolytica as indicated by ELISA with sonicated amebic protein or by immunofluorescence assay with fixed whole trophozoites. Tissue culture supernatants were further screened for subcloning by the ability to bind to Chinese hamster ovary (CHO) cells which were first exposed to a partially purified soluble preparation of the amebic GalNAc-inhibitable lectin. Eight tissue culture supernatants were positive in this assay. Antibodies from four subcloned cell lines (D3-14, H8-5, I12-2, and I1-21) inhibited amebic adherence to CHO cells (P less than 0.01). Of the original 35 tissue culture supernatants, 3 also inhibited amebic adherence (P less than 0.01; F1, F14, and J10); monoclonal antibodies in these supernatants did not bind to lectin-exposed CHO cells. Three purified monoclonal antibodies (H8-5, I12-2, and I1-21) inhibited amebic adherence at greater than or equal to 2 micrograms/10(4) amebae (P less than 0.05). None of these inhibitory monoclonal antibodies immunoprecipitated with a soluble amebic protein preparation following sodium dodecyl sulfate-polyacrylamide gel electrophoresis under denaturing conditions. Monoclonal antibodies which inhibit in vitro adherence by E. histolytica will be useful in purification of the GalNAc-inhibitable lectin. PMID:2873102

  16. Properties of silver and copper nanoparticle-containing aqueous solutions and evaluation of their in vitro activity against Candida albicans and Staphylococcus aureus biofilms

    NASA Astrophysics Data System (ADS)

    Montes Aguirre, Melissa Mariluz

    Most microorganisms grow on surfaces as biofilms rather than as individual planktonic cells, and cells within biofilms show high levels of resistance against antimicrobial drugs. Thereby biofilm formation complicates treatment and contributes to high morbidity and mortality rates associated with infections. This study explores the physical, optical, and nano-structural properties of selected nanoparticles dispersed in aqueous solutions (nanoparticulate colloidal water or nanofluids) and examines their in vitro activity against microbial biofilms. Silver and copper nanofluids of various concentrations were prepared and studied. Their surface energies, surface charge and surface plasmonic resonance properties were obtained using contact angle measurement, zeta potential and optical spectrometer, respectively. The temperature dependence of the surface plasmon resonance behavior was also determined for the selected nanoparticulate aqueous solutions. A model of biofilm formation on the wells of microtiter plates was used to determine the in vitro activity of the nanoparticle preparations against both fungal (Candida albicans) and bacterial (Staphylococcus aureus) biofilms. Scanning electron microscopy (SEM) was used to observe the nanoparticle interactions with microbial cells. Results show that silver nanofluid has higher surface energy than that of the copper, the surface energy increases as the concentration of silver nanoparticles increases; and both nanoparticles in liquid are positively charged. The interaction between silver nanoparticles and water molecules produces notable changes on the usual temperature properties of water. Altogether, effectiveness of silver nanoparticle-containing liquids in controlling biofilm formation is observed and reported. For a given size of silver nanoparticles studied, it is found that the effective concentrations of silver nanoparticles against microbial biofilms are far lower than their cytotoxic concentrations, indicating an

  17. Persea americana Glycolic Extract: In Vitro Study of Antimicrobial Activity against Candida albicans Biofilm and Cytotoxicity Evaluation.

    PubMed

    Jesus, D; Oliveira, J R; Oliveira, F E; Higa, K C; Junqueira, J C; Jorge, A O C; Back-Brito, G N; Oliveira, L D

    2015-01-01

    This study evaluated the antifungal activity of Persea americana extract on Candida albicans biofilm and its cytotoxicity in macrophage culture (RAW 264.7). To determine the minimum inhibitory concentration (MIC), microdilution in broth (CLSI M27-S4 protocol) was performed. Thereafter, the concentrations of 12.5, 25, 50, 100, and 200 mg/mL (n = 10) with 5 min exposure were analyzed on mature biofilm in microplate wells for 48 h. Saline was used as control (n = 10). After treatment, biofilm cells were scraped off and dilutions were plated on Sabouraud dextrose agar. After incubation (37°C/48 h), the values of colony forming units per milliliter (CFU/mL) were converted to log10 and analyzed (ANOVA and Tukey test, 5%). The cytotoxicity of the P. americana extract was evaluated on macrophages by MTT assay. The MIC of the extract was 6.25 mg/mL and with 12.5 mg/mL there was elimination of 100% of planktonic cultures. Regarding the biofilms, a significant reduction (P < 0.001) of the biofilm at concentrations of 50 (0.580 ± 0.209 log10), 100 (0.998 ± 0.508 log10), and 200 mg/mL (1.093 ± 0.462 log10) was observed. The concentrations of 200 and 100 mg/mL were cytotoxic for macrophages, while the concentrations of 50, 25, and 12.5 mg/mL showed viability higher than 55%. PMID:26605376

  18. Persea americana Glycolic Extract: In Vitro Study of Antimicrobial Activity against Candida albicans Biofilm and Cytotoxicity Evaluation

    PubMed Central

    Jesus, D.; Oliveira, J. R.; Oliveira, F. E.; Higa, K. C.; Junqueira, J. C.; Jorge, A. O. C.; Back-Brito, G. N.; Oliveira, L. D.

    2015-01-01

    This study evaluated the antifungal activity of Persea americana extract on Candida albicans biofilm and its cytotoxicity in macrophage culture (RAW 264.7). To determine the minimum inhibitory concentration (MIC), microdilution in broth (CLSI M27-S4 protocol) was performed. Thereafter, the concentrations of 12.5, 25, 50, 100, and 200 mg/mL (n = 10) with 5 min exposure were analyzed on mature biofilm in microplate wells for 48 h. Saline was used as control (n = 10). After treatment, biofilm cells were scraped off and dilutions were plated on Sabouraud dextrose agar. After incubation (37°C/48 h), the values of colony forming units per milliliter (CFU/mL) were converted to log10 and analyzed (ANOVA and Tukey test, 5%). The cytotoxicity of the P. americana extract was evaluated on macrophages by MTT assay. The MIC of the extract was 6.25 mg/mL and with 12.5 mg/mL there was elimination of 100% of planktonic cultures. Regarding the biofilms, a significant reduction (P < 0.001) of the biofilm at concentrations of 50 (0.580 ± 0.209 log10), 100 (0.998 ± 0.508 log10), and 200 mg/mL (1.093 ± 0.462 log10) was observed. The concentrations of 200 and 100 mg/mL were cytotoxic for macrophages, while the concentrations of 50, 25, and 12.5 mg/mL showed viability higher than 55%. PMID:26605376

  19. Inhibition of human topoisomerase II in vitro by bioactive benzene metabolites

    SciTech Connect

    Frantz, C.E.; Chen, Hongwei; Eastmond, D.A.

    1996-12-01

    Benzene is a clastogenic and carcinogenic agent that induces acute myelogenous leukemia in humans and multiple types of tumors in animals. Previous research has indicated that benzene must first be metabolized to one or more bioactive species to exert its myelotoxic and genotoxic effects. To better understand the possible role of individual benzene metabolites in the leukemogenic process, as well as to further investigate inhibition of topoisomerase 11 by benzene metabolites, a series of known and putative benzene metabolites, phenol, 4{prime}4-biphenol, 2,2{prime}-biphenol, hydroquinone, catechol, 1,2,4-benzenetriol, 1,4-benzoquinone, and trans-trans-muconaldehyde were tested for inhibitory effects in vitro on the human topoisomerase 11 enzyme. With minor modifications of the standard assay conditions, 1,4-benzoquinone and trans-trans-muconaldehyde were shown to be directly inhibitory, whereas all of the phenolic metabolites were shown to inhibit enzymatic activity following bioactivation using a peroxidase activation system. The majority of compounds tested inhibited topoisomerase 11 at concentrations at or below 10 pM. These results confirm and expand upon previous findings from our laboratory and indicate that many of the metabolites of benzene could potentially interfere with topoisomerase 11. Since other inhibitors of topoisomerase 11 have been shown to induce leukemia in humans, inhibition of this enzyme by benzene metabolites may also play a role in the carcinogenic effects of benzene. 48 refs., 4 tabs.

  20. In vitro developmental toxicity test detects inhibition of stem cell differentiation by silica nanoparticles

    SciTech Connect

    Park, Margriet V.D.Z. Annema, Wijtske; Salvati, Anna; Lesniak, Anna; Elsaesser, Andreas; Barnes, Clifford; McKerr, George; Howard, C. Vyvyan; Lynch, Iseult; Dawson, Kenneth A.; Piersma, Aldert H.; Jong, Wim H. de

    2009-10-01

    While research into the potential toxic properties of nanomaterials is now increasing, the area of developmental toxicity has remained relatively uninvestigated. The embryonic stem cell test is an in vitro screening assay used to investigate the embryotoxic potential of chemicals by determining their ability to inhibit differentiation of embryonic stem cells into spontaneously contracting cardiomyocytes. Four well characterized silica nanoparticles of various sizes were used to investigate whether nanomaterials are capable of inhibition of differentiation in the embryonic stem cell test. Nanoparticle size distributions and dispersion characteristics were determined before and during incubation in the stem cell culture medium by means of transmission electron microscopy (TEM) and dynamic light scattering. Mouse embryonic stem cells were exposed to silica nanoparticles at concentrations ranging from 1 to 100 {mu}g/ml. The embryonic stem cell test detected a concentration dependent inhibition of differentiation of stem cells into contracting cardiomyocytes by two silica nanoparticles of primary size 10 (TEM 11) and 30 (TEM 34) nm while two other particles of primary size 80 (TEM 34) and 400 (TEM 248) nm had no effect up to the highest concentration tested. Inhibition of differentiation of stem cells occurred below cytotoxic concentrations, indicating a specific effect of the particles on the differentiation of the embryonic stem cells. The impaired differentiation of stem cells by such widely used particles warrants further investigation into the potential of these nanoparticles to migrate into the uterus, placenta and embryo and their possible effects on embryogenesis.

  1. The rhizobacterium Arthrobacter agilis produces dimethylhexadecylamine, a compound that inhibits growth of phytopathogenic fungi in vitro.

    PubMed

    Velázquez-Becerra, Crisanto; Macías-Rodríguez, Lourdes I; López-Bucio, José; Flores-Cortez, Idolina; Santoyo, Gustavo; Hernández-Soberano, Christian; Valencia-Cantero, Eduardo

    2013-12-01

    Plant diseases caused by fungal pathogens such as Botrytis cinerea and the oomycete Phytophthora cinnamomi affect agricultural production worldwide. Control of these pests can be done by the use of fungicides such as captan, which may have deleterious effects on human health. This study demonstrates that the rhizobacterium Arthrobacter agilis UMCV2 produces volatile organic compounds that inhibit the growth of B. cinerea in vitro. A single compound from the volatile blends, namely dimethylhexadecylamine (DMHDA), could inhibit the growth of both B. cinerea and P. cinnamomi when supplied to the growth medium in low concentrations. DMHDA also inhibited the growth of beneficial fungi Trichoderma virens and Trichoderma atroviride but at much higher concentrations. DMHDA-related aminolipids containing 4, 8, 10, 12, and 14 carbons in the alkyl chain were tested for their inhibitory effect on the growth of the pathogens. The results show that the most active compound from those tested was dimethyldodecylamine. This effect correlates with a decrease in the number of membrane lipids present in the mycelium of the pathogen including eicosanoic acid, (Z)-9-hexadecenoic acid, methyl ester, and (Z)-9-octadecenoic acid, methyl ester. Strawberry leaflets treated with DMHDA were not injured by the compound. These data indicate that DMHDA and related compounds, which can be produced by microorganisms may effectively inhibit the proliferation of certain plant pathogens. PMID:23674267

  2. The flavonoid tangeretin inhibits invasion of MO4 mouse cells into embryonic chick heart in vitro.

    PubMed

    Bracke, M E; Vyncke, B M; Van Larebeke, N A; Bruyneel, E A; De Bruyne, G K; De Pestel, G H; De Coster, W J; Espeel, M F; Mareel, M M

    1989-01-01

    Tangeretin, a flavonoid from citrus plants, was found to inhibit the invasion of MO4 cells (Kirsten murine sarcoma virus transformed fetal mouse cells) into embryonic chick heart fragments in vitro. The flavonoid appeared to be chemically stable in tissue culture medium, and the anti-invasive effect was reversible on omission of the molecule from the medium. Unlike (+)-catechin, another anti-invasive flavonoid, tangeretin bound poorly to extracellular matrix. It did not alter fucosylated surface glycopeptides of MO4 cells. Tangeretin seemed not to act as a microtubule inhibitor, as immunocytochemistry revealed no disturbance of the cytoplasmic microtubule complex. However, at anti-invasive concentrations of tangeretin, cell proliferation and thymidine incorporation appeared to be inhibited. When cultured on an artificial substrate, treated MO4 cells were less elongated, covered a larger surface area and exhibited a slower directional migration than untreated cells. From the decrease in ATP content in MO4 cells after tangeretin treatment, we deduce that this flavonoid inhibits a number of intracellular processes, which leads to an inhibition of cell motility and hence of invasion. PMID:2924447

  3. Crude Aloe vera Gel Shows Antioxidant Propensities and Inhibits Pancreatic Lipase and Glucose Movement In Vitro.

    PubMed

    Taukoorah, Urmeela; Mahomoodally, M Fawzi

    2016-01-01

    Aloe vera gel (AVG) is traditionally used in the management of diabetes, obesity, and infectious diseases. The present study aimed to investigate the inhibitory potential of AVG against α-amylase, α-glucosidase, and pancreatic lipase activity in vitro. Enzyme kinetic studies using Michaelis-Menten (K m ) and Lineweaver-Burk equations were used to establish the type of inhibition. The antioxidant capacity of AVG was evaluated for its ferric reducing power, 2-diphenyl-2-picrylhydrazyl hydrate scavenging ability, nitric oxide scavenging power, and xanthine oxidase inhibitory activity. The glucose entrapment ability, antimicrobial activity, and total phenolic, flavonoid, tannin, and anthocyanin content were also determined. AVG showed a significantly higher percentage inhibition (85.56 ± 0.91) of pancreatic lipase compared to Orlistat. AVG was found to increase the Michaelis-Menten constant and decreased the maximal velocity (V max) of lipase, indicating mixed inhibition. AVG considerably inhibits glucose movement across dialysis tubes and was comparable to Arabic gum. AVG was ineffective against the tested microorganisms. Total phenolic and flavonoid contents were 66.06 ± 1.14 (GAE)/mg and 60.95 ± 0.97 (RE)/mg, respectively. AVG also showed interesting antioxidant properties. The biological activity observed in this study tends to validate some of the traditional claims of AVG as a functional food. PMID:26880905

  4. Induction of sister chromatid exchanges and inhibition of cellular proliferation in vitro. I. Caffeine

    SciTech Connect

    Guglielmi, G.E.; Vogt, T.F.; Tice, R.R.

    1982-01-01

    While many agents have been examined for their ability to induce SCE's, complete dose-response information has often been lacking. We have reexamined the ability of one such compound - caffeine - to induce SCEs and also to inhibit cellular proliferation in human peripheral lymphocytes in vitro. An acute exposure to caffeine prior to the DNA synthetic period did not affect either SCE frequency or the rate of cellular proliferation. Chronic exposure to caffeine throughout the culture period lead to both a dose-dependent increase in SCEs (SCE/sub d/ or doubling dose = 2.4 mM; SCE/sub 10/ or the dose capable of inducing 10 SCE = 1.4 mM) and a dose-dependent inhibition of cellular proliferation (IC/sub 50/ or the 50% inhibition concentration = 2.6 mM). The relative proportion of first generation metaphase cells, an assessment of proliferative inhibiton, increased linearly with increasing caffeine concentrations. However, SCE frequency increased nonlinearly over the same range of caffeine concentrations. Examination of the ratio of nonsymmetrical to symmetrical SCEs in third generation metaphase cells indicated that caffeine induced SCEs in equal frequency in each of three successive generations. The dependency of SCE induction and cellular proliferative inhibition on caffeine's presence during the DNA synthetic period suggests that caffeine may act as an antimetabolite in normal human cells.

  5. Heparin inhibition of von Willebrand factor-dependent platelet function in vitro and in vivo.

    PubMed Central

    Sobel, M; McNeill, P M; Carlson, P L; Kermode, J C; Adelman, B; Conroy, R; Marques, D

    1991-01-01

    The intravenous administration of heparin to patients before open heart surgery reduced ristocetin cofactor activity by 58% (P less than 0.01, t test), and this impairment of von Willebrand factor-dependent platelet function was closely related to plasma heparin levels (r2 = 0.9), but not to plasma von Willebrand factor (vWF) levels. We hypothesized that heparin may inhibit vWF-dependent platelet hemostatic functions by directly binding vWF in solution and interfering with vWF-GpIb binding. Using the in vitro techniques of ristocetin-induced platelet agglutination, fluorescent flow cytometric measurement of vWF-platelet binding, and conventional radioligand binding assays we observed that heparin inhibited both vWF-dependent platelet function and vWF-platelet binding in a parallel and dose-dependent manner. Heparin also inhibited platelet agglutination induced by bovine vWF and inhibited the binding of human asialo-vWF to platelets in ristocetin-free systems. The inhibitory potency of heparin was not dependent upon its affinity for antithrombin III, but was molecular weight dependent: homogeneous preparations of lower molecular weight were less inhibitory. Heparin impairment of vWF function may explain why some hemorrhagic complications of heparin therapy are not predictable based on techniques for monitoring the conventional anticoagulant effects of heparin. PMID:2022745

  6. In Vitro α-Amylase Inhibition and Antioxidant Activities of Methanolic Extract of Amaranthus Caudatus Linn

    PubMed Central

    Kumar, Ashok; Khan, Saleemulla

    2011-01-01

    Objectives The present study was aimed to investigate the α-amylase inhibition and antioxidant activities of methanolic extract of Amaranthus caudatus Linn (MeAc). Methods Methanolic extract of Amaranthus caudatus was screened for α-amylase inhibition activity by CNPG3 method (2-chloro-p-nitrophenyl-α-D-maltotrioside) and antioxidant activity was evaluated by 1,1-diphenyl-2-picryl-hydrazile (DPPH) free radical scavenging, superoxide dismutase (SOD) scavenging, hydroxyl free radical scavenging, nitric oxide (NO) radical scavenging, and 2.2’-azinobis-3-ethylbenzothiazole-6-sulfonic acid (ABTS) radical scavenging assays. MeAc was also screened for non enzymatic hemoglycosylation. Results The methanolic extract of Amaranthus caudatus showed potent α-amylase inhibition activity (IC50 19.233 µg/ml). MeAc showed significant antioxidant activity in all the in vitro antioxidant models. Furthermore, the MeAc was found to be extremely effective in scavenging ABTS radical activity (IC50 48.75±1.1 µg/ml) when compared to DPPH (IC50 77.5±0.4 µg/ml), SOD (IC50 62.5±2.1 µg/ml), hydroxyl (IC50 88.50±1.8 µg/ml) and NO (IC50 67.5±2.2 µg/ml) scavenging activity. Conclusions The methanolic extract of A. caudatus showed potent α-amylase inhibition and antioxidant activities. PMID:22043408

  7. Crude Aloe vera Gel Shows Antioxidant Propensities and Inhibits Pancreatic Lipase and Glucose Movement In Vitro

    PubMed Central

    Taukoorah, Urmeela; Mahomoodally, M. Fawzi

    2016-01-01

    Aloe vera gel (AVG) is traditionally used in the management of diabetes, obesity, and infectious diseases. The present study aimed to investigate the inhibitory potential of AVG against α-amylase, α-glucosidase, and pancreatic lipase activity in vitro. Enzyme kinetic studies using Michaelis-Menten (Km) and Lineweaver-Burk equations were used to establish the type of inhibition. The antioxidant capacity of AVG was evaluated for its ferric reducing power, 2-diphenyl-2-picrylhydrazyl hydrate scavenging ability, nitric oxide scavenging power, and xanthine oxidase inhibitory activity. The glucose entrapment ability, antimicrobial activity, and total phenolic, flavonoid, tannin, and anthocyanin content were also determined. AVG showed a significantly higher percentage inhibition (85.56 ± 0.91) of pancreatic lipase compared to Orlistat. AVG was found to increase the Michaelis-Menten constant and decreased the maximal velocity (Vmax) of lipase, indicating mixed inhibition. AVG considerably inhibits glucose movement across dialysis tubes and was comparable to Arabic gum. AVG was ineffective against the tested microorganisms. Total phenolic and flavonoid contents were 66.06 ± 1.14 (GAE)/mg and 60.95 ± 0.97 (RE)/mg, respectively. AVG also showed interesting antioxidant properties. The biological activity observed in this study tends to validate some of the traditional claims of AVG as a functional food. PMID:26880905

  8. An in vitro approach to estimate putative inhibition of buprenorphine and norbuprenorphine glucuronidation.

    PubMed

    Oechsler, Stephanie; Skopp, Gisela

    2010-05-01

    An in vitro inhibition study was performed to investigate potential drug-drug interactions on glucuronidation of buprenorphine (BUP) and norbuprenorphine (NBUP), which represents the major elimination pathway of the drug using cDNA-expressed uridine 5'-diphosphate glucuronosyltransferases (UGTs) and human liver microsomes (HLMs). Following identification of major UGT enzymes for BUP and NBUP glucuronidation, substrates were incubated with drugs (amitriptyline, nortriptyline, lamotrigine, oxazepam, and temazepam), which are extensively cleared by glucuronidation as well as are often used during maintenance treatment. To evaluate the inhibitory potential, the half maximal inhibitor concentration (IC(50)), the inhibition constant (K (i)), and the inhibitor concentration (K (I)) that yield half the maximum rate of inactivation and the enzyme inactivation rate constant (k (inact)) were determined, if appropriate. Amitriptyline and temazepam are inhibitors of NBUP glucuronidation (UGT1A3, HLMs), whereas BUP glucuronidation was affected by amitriptyline (HLMs), oxazepam, and temazepam (UGT2B7). Additionally, BUP inhibits NBUP glucuronidation (UGT1A1, 1A3, HLMs) and vice versa (UGT1A3). A decrease in the metabolic clearance of NBUP may increase the risk of adverse effects such as respiratory depression. Further investigations are needed to evaluate whether inhibition of BUP and NBUP glucuronidation contributes to adverse events. PMID:20111869

  9. Vitamin K enhancement of Sorafenib-mediated HCC cell growth inhibition in vitro and in vivo

    PubMed Central

    Wei, Gang; Wang, Meifanf; Hyslop, Terry; Wang, Ziqiu; Carr, Brian I.

    2010-01-01

    The multi-kinase inhibitor Sorafenib, is the first oral agent to show activity against human hepatocellular carcinoma (HCC). Apoptosis has been shown to be induced in HCC by several agents, including Sorafenib, as well as by the naturally occurring K vitamins (VKs). Since few non toxic agents have activity against HCC growth, we evaluated the activity of Sorafenib and K vitamins, both independently and together on the growth in vitro and in vivo of HCC cells. We found that when VK was combined with Sorafenib, the concentration of Sorafenib required for growth inhibition was substantially reduced. Conversely, VK enhanced Sorafenib effects in several HCC cell lines on growth inhibition. Growth could be inhibited at doses of VK plus Sorafenib that were ineffective with either agent alone,using vitamins K1, K2 and K5. Combination VK1 plus Sorafenib induced apoptosis on FACS, TUNEL staining and caspase activation. Phospho-ERK levels were decreased, as was Mcl-1, an ERK target. Sorafenib alone inhibited growth of transplantable HCC in vivo. At sub-effective Sorafenib doses in vivo, addition of VK1 caused major tumor regression, with decreased phospho-ERK and Mcl-1 staining. Thus, combination VK1 plus Sorafenib strongly induced growth inhibition and apoptosis in rodent and human HCC and inhibited the RAF/MEK/ERK pathway. VK1 alone activated PKA, a mediator of inhibitory Raf phosphorylation. Thus, each agent can antagonize Raf; Sorafenib as a direct inhibitor and VK1 through inhibitory Raf phosphorylation. Since both agents are available for human use, the combination has potential for improving Sorafenib effects in HCC. PMID:21351273

  10. Mithramycin inhibits SP1 binding and selectively inhibits transcriptional activity of the dihydrofolate reductase gene in vitro and in vivo.

    PubMed Central

    Blume, S W; Snyder, R C; Ray, R; Thomas, S; Koller, C A; Miller, D M

    1991-01-01

    The promoter of the human dihydrofolate reductase (DHFR) gene contains two consensus binding sites for the DNA binding protein Sp1. DNAse protection and gel mobility shift assays demonstrate binding of recombinant Sp1 to both decanucleotide Sp1 binding sequences which are located 49 and 14 base pairs upstream of the transcription start site. The more distal of the two binding sites exhibits a somewhat higher affinity for Sp1. The G-C specific DNA binding drug, mithramycin, binds to both consensus sequences and prevents subsequent Sp1 binding. Promoter-dependent in vitro transcription of a DHFR template is selectively inhibited by mithramycin when compared to the human H2b histone gene. A similar effect is also noted in vivo. Mithramycin treatment of MCF-7 human breast carcinoma cells containing an amplified DHFR gene induces selective inhibition of DHFR transcription initiation, resulting in a decline in DHFR mRNA level and enzyme activity. This selective inhibition of DHFR expression suggests that it is possible to modulate the overexpression of the DHFR gene in methotrexate resistant cells. Images PMID:1834700