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Sample records for potent anticariogenic activity

  1. Anticariogenic Activity of Black Tea - An Invivo Study

    PubMed Central

    Arya, Vishal; Srivastava, Ankit; Nandlal, Swati

    2016-01-01

    Introduction Teas is known for its anticariogenic properties and various mechanisms have been invoked to explain this effect. One such proposed mechanism is inhibition of salivary alpha amylase activity by endogenous tannins present in tea. Aim The objective of the present study was to determine whether or not the ingestion of black tea decoction inhibits the enzyme salivary amylase and thus interferes with the release of maltose from intraoral entrapped particles of food. Materials and Methods A total of 30 children in the age group of 12 - 15 years were selected for the study. After two hours of fasting subjects consumed two salted crackers for 60 second following which they rinsed with water (control solution) and then with 1.5% black tea decoction (test solution) next day. Retained food particles were recovered from buccal aspect of left mandibular premolar and salivary amylase activity was noted via chromatography. Paired t-test was applied for statistical analysis. Results Maltose to Sucrose ratio was used to evaluate the result. The average ratio was 3.27 for control solution and 1.82 for test solution. The results were statistically highly significant (p <0.005). Conclusion Tea inhibited the activity of salivary amylase and this inhibition assumes a special significance when it is considered that the effect of tea could be manifested over a prolonged period of time, as in a real life situation. PMID:27135007

  2. Anticariogenic activity of some tropical medicinal plants against Streptococcus mutans.

    PubMed

    Hwang, Jae-Kwan; Shim, Jae-Seok; Chung, Jae-Youn

    2004-09-01

    The methanol extracts of five tropical plants, Baeckea frutescens, Glycyrrhiza glabra, Kaempferia pandurata, Physalis angulata and Quercus infectoria, exhibited potent antibacterial activity against the cariogenic bacterium Streptococcus mutans. In particular, G. glabra, K. pandurata and P. angulata conferred fast killing bactericidal effect against S. mutans in 2 min at 50 microg/ml of extract concentration.

  3. Anticariogenic activity and phytochemical studies of crude extract from some Indian plant leaves

    PubMed Central

    Barad, Mahesh K.; Ishnava, Kalpesh B.; Chauhan, Jenabhai B.

    2014-01-01

    Aim: The aim was to screen the selected Indian plants for their antibacterial efficacy against four cariogenic bacteria Lactobacillus acidophilus (LA)(Microbial Type Culture Collection [MTCC]-*447), Lactobacillus casei (LC) (MTCC-1423), Streptococcus mutans (SMU) (MTCC-890) and Staphylococcus aureus (MTCC-96). To identify and characterize active principle present in these plants for the treatment of dental caries. Materials and Methods: The dried plant leaves materials are extracted by cold extraction using hexane, ethyl acetate, methanol, and distilled water. The solvents were evaporated, and the dried masses were suspended in dimethyl sulfoxide and used for anticariogenic activity by agar well diffusion method. Minimum inhibitory concentration (MIC) was evaluated by two-fold serial broth dilution method. Preliminary phytochemical analysis of effective extract was carried out by thin-layer chromatography (TLC) and bioautography. Results: Ethyl acetate and hexane extract of Eucalyptus globules was found most effective against L. acidophilus with MIC value 31 μg/ml and 62 μg/ml, respectively. Ethyl acetate extracts of Acacia nilotica and methanolic extract of E. globules also exhibited antibacterial activity against SMU and L. casei with MIC value of 50 μg/ml. Qualitative analysis of E. globules revealed the presence of alkaloids, terpenoids, phenolic compounds, and cardiac glycosides. The active principle responsible for the anticariogenic activity from E. globules were separated by TLC and subjected to bioautography using SMU, LA and LC. Conclusion: Anticariogenic activity and preliminary phytochemical analysis revealed that E. globule have potential to treat dental caries. PMID:26401353

  4. Anticariogenic activity and phytochemical studies of crude extract from some Indian plant leaves.

    PubMed

    Barad, Mahesh K; Ishnava, Kalpesh B; Chauhan, Jenabhai B

    2014-01-01

    The aim was to screen the selected Indian plants for their antibacterial efficacy against four cariogenic bacteria Lactobacillus acidophilus (LA)(Microbial Type Culture Collection [MTCC]-*447), Lactobacillus casei (LC) (MTCC-1423), Streptococcus mutans (SMU) (MTCC-890) and Staphylococcus aureus (MTCC-96). To identify and characterize active principle present in these plants for the treatment of dental caries. The dried plant leaves materials are extracted by cold extraction using hexane, ethyl acetate, methanol, and distilled water. The solvents were evaporated, and the dried masses were suspended in dimethyl sulfoxide and used for anticariogenic activity by agar well diffusion method. Minimum inhibitory concentration (MIC) was evaluated by two-fold serial broth dilution method. Preliminary phytochemical analysis of effective extract was carried out by thin-layer chromatography (TLC) and bioautography. Ethyl acetate and hexane extract of Eucalyptus globules was found most effective against L. acidophilus with MIC value 31 μg/ml and 62 μg/ml, respectively. Ethyl acetate extracts of Acacia nilotica and methanolic extract of E. globules also exhibited antibacterial activity against SMU and L. casei with MIC value of 50 μg/ml. Qualitative analysis of E. globules revealed the presence of alkaloids, terpenoids, phenolic compounds, and cardiac glycosides. The active principle responsible for the anticariogenic activity from E. globules were separated by TLC and subjected to bioautography using SMU, LA and LC. Anticariogenic activity and preliminary phytochemical analysis revealed that E. globule have potential to treat dental caries.

  5. Anticariogenic and Hemolytic Activity of Selected Seed Protein Extracts In vitro conditions

    PubMed Central

    Ishnava, Kalpesh B; Shah, Pankit P.

    2014-01-01

    Objective: This study aimed to assess the anticariogenic and hemolytic activity of crude plant seed protein extracts against tooth decaying bacteria. Materials and Methods: The proteins from seeds of 12 different plants were extracted and used for antimicrobial assay against six different organisms. The extraction was carried out in 10mM of sodium phosphate buffer (pH 7.0). Protein concentrations were determined as described by Bradford method. Anticariogenic activity was studied by agar well diffusion method and Minimum Inhibitory Concentration (MIC) was evaluated by the two-fold serial broth dilution method. Hemolytic activity, treatment of proteinase K and Kinetic study in Mimusops elengi crude seed protein extract. Results: The anticariogenic assay demonstrated the activity of Mimusops elengi against Staphylococcus aureus and Streptococcus pyogenes. A minor activity of Glycine wightii against Streptococcus mutans was also found. The protein content of Mimusops elengi seed protein extract was 5.84mg/ml. The MIC values for Staphylococcus aureus and Streptococcus pyogenes against Mimusops elengi seed protein extract were 364.36μg/ml and 182.19μg/ml, respectively. Kinetic study further elucidated the mode of inhibition in the presence of the Mimusops elengi plant seed protein with respect to time. The concentration of crude extract which gave 50% hemolysis compared to Triton X-100 treatment (HC50) value was 1.58 mg/ml; which is more than five times larger than that of the MIC. Treatment with proteinase K of the Mimusops elengi seed protein resulted in absence of the inhibition zone; which clearly indicates that the activity was only due to protein. Conclusion: Our results showed the prominence of Mimusops elengi plant seed protein extract as an effective herbal medication against tooth decaying bacteria. PMID:25628685

  6. Anticariogenic activity of macelignan isolated from Myristica fragrans (nutmeg) against Streptococcus mutans.

    PubMed

    Chung, J Y; Choo, J H; Lee, M H; Hwang, J K

    2006-03-01

    The occurrence of dental caries is mainly associated with oral pathogens, especially cariogenic Streptococcus mutans. Preliminary antibacterial screening revealed that the extract of Myristica fragrans, widely cultivated for the spice and flavor of foods, possessed strong inhibitory activity against S. mutans. The anticariogenic compound was successfully isolated from the methanol extract of M. fragrans by repeated silica gel chromatography, and its structure was identified as macelignan by instrumental analysis using 1D-NMR, 2D-NMR and EI-MS. The minimum inhibitory concentration (MIC) of macelignan against S. mutans was 3.9 microg/ml, which was much lower than those of other natural anticariogenic agents such as 15.6 microg/ml of sanguinarine, 250 microg/ml of eucalyptol, 500 microg/ml of menthol and thymol, and 1000 microg/ml of methyl salicylate. Macelignan also possessed preferential activity against other oral microorganisms such as Streptococcus sobrinus, Streptococcus salivarius, Streptococcus sanguis, Lactobacillus acidophilus and Lactobacillus casei in the MIC range of 2-31.3 microg/ml. In particular, the bactericidal test showed that macelignan, at a concentration of 20 microg/ml, completely inactivated S. mutans in 1 min. The specific activity and fast-effectiveness of macelignan against oral bacteria strongly suggest that it could be employed as a natural antibacterial agent in functional foods or oral care products.

  7. Long-term anti-cariogenic biofilm activity of glass ionomers related to fluoride release.

    PubMed

    Chau, Ngoc Phuong Thanh; Pandit, Santosh; Jung, Ji-Eun; Cai, Jian-Na; Yi, Ho-Keun; Jeon, Jae-Gyu

    2016-04-01

    The aim of this study was to evaluate the difference between anti-cariogenic biofilm activities of glass ionomers (G-Is) during the initial and second fluoride release phases and to define relationships between the anti-biofilm activities and fluoride release. Fluoride release of three commercially available G-Is in a buffer was evaluated for 770 h, and then 70-h-old Streptococcus mutans UA159 biofilms were formed on the G-Is that had been immersed in the buffer for 0, 100, 200, or 700 h. The dry weight, bacterial cell number, water-insoluble extracellular polysaccharides (EPSs), and accumulated fluoride concentration of the 70-h-old biofilms and fluoride release and acid production rates during biofilm formation were determined. Relationships between the experimental variables and fluoride release rate were also evaluated using linear regression analysis. In this study, fluoride release of the tested G-Is did not exhibit a biphasic pattern during biofilm formation. The release was sustained or did not rapidly decrease even over long immersion periods and was strongly correlated with an increase in accumulated fluoride concentration of the biofilms (R=0.99, R(2)=0.98) and reductions in dry weight, water-insoluble EPSs, and acid production rate of the biofilms (R=-0.99 to -0.96, R(2)=0.92-0.98). This study suggests that G-Is can effectively affect acid production, EPS formation, and accumulation of cariogenic biofilms even during the second fluoride release phase, and that the anti-cariogenic biofilm activity is strongly correlated with fluoride release, which may be enhanced by acid production of cariogenic biofilms. G-Is can affect cariogenic biofilm formation even during the second fluoride release phase. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Anticariogenic effects of tea in rats.

    PubMed

    Rosen, S; Elvin-Lewis, M; Beck, F M; Beck, E X

    1984-05-01

    Teas varying in fluoride and tannin concentration were evaluated in rats for anticariogenic activity. There was a direct correlation between fluoride in tea and the inhibition of sulcal caries in rats, whereas no relationship was observed between tannin and this type of lesion. Teas also had a significant effect on caries progression and imparted a black stain to the teeth.

  9. Salivaricin E and abundant dextranase activity may contribute to the anti-cariogenic potential of the probiotic candidate Streptococcus salivarius JH.

    PubMed

    Walker, Glenn V; Heng, Nicholas C K; Carne, Alan; Tagg, John R; Wescombe, Philip A

    2016-03-01

    Dental caries is an infectious disease that is continuing to increase in prevalence, reducing the quality of life for millions worldwide as well as causing considerable expense, with an estimated US$108 billion spent on dental care in the USA each year. Oral probiotics are now being investigated to determine whether they could play a role in the prevention and treatment of this disease. Streptococcus salivarius strain JH is a potential probiotic candidate that produces multiple proteinaceous antimicrobials (bacteriocins), the inhibitory spectrum of which includes Streptococcus mutans, one of the principal causative agents of dental caries. The genome of strain JH has previously been shown to contain the biosynthetic loci for the bacteriocins salivaricin A3, streptin and streptococcin SA-FF22. Here we show that strain JH also produces salivaricin E, a 32 aa lantibiotic with a mass of 3565.9 Da, which is responsible for the inhibition of S. mutans growth. In addition, strain JH was shown to produce dextranase, an enzyme that hydrolyses (1 → 6)-α-D-glucosidic linkages, at levels higher than any other S. salivarius tested. In vitro testing showed that partial hydrolysis of the exopolymeric substances of S. mutans, using strain JH dextranase, improved the anti-S. mutans inhibitory activity of the lytic bacteriocin, zoocin A. The multiple bacteriocin and dextranase activities of strain JH support its candidature for development as an oral probiotic.

  10. Dimers of nostocarboline with potent antibacterial activity.

    PubMed

    Locher, Hans H; Ritz, Daniel; Pfaff, Philippe; Gaertner, Mika; Knezevic, Andreja; Sabato, Daniela; Schroeder, Susanne; Barbaras, Damien; Gademann, Karl

    2010-01-01

    In this study, the in vitro antimicrobial activity and spectrum of new dimeric compounds derived from the cyanobacterial alkaloid nostocarboline were investigated. The mechanism of action and selectivity to bacteria were studied and compared to the cationic antiseptic chlorhexidine. Minimal inhibitory concentrations were determined against clinical isolates and against a panel of microbial reference strains using the CLSI microdilution method. Bacterial membrane damage was addressed by measuring ATP leakage and the mode of action was investigated in Escherichia coli reporter strains. Selectivity was tested by a cytotoxicity assay using MTS. The antimicrobial potency of dimers varied with length of the hydrophobic linker. The most potent compounds, NCD9 and NCD10, had a C10 and C12 linker, respectively, and showed strong activity against Gram-positive bacteria, notably methicillin-resistant Staphylococcus aureus strains. Similar to chlorhexidine, these compounds showed a rapid concentration-dependent bactericidal effect, which correlated with membrane damage as indicated by ATP leakage. NCD9, in contrast to NCD10 and chlorhexidine, lacked activity against yeast strains and showed low cytotoxicity in CHO cells indicating a high degree of selectivity. In E. coli reporter strains, NCD9 induced the DegP response pathway as well as the SOS response, suggesting interaction with both the cell envelope and DNA metabolism. The results presented in this report indicate the potential of this new class of cationic antimicrobial compounds for the design of potent and selective antibacterials with low cytotoxicity. Copyright © 2010 S. Karger AG, Basel.

  11. Anticariogenic and phytochemical evaluation of Eucalyptus globules Labill.

    PubMed Central

    Ishnava, Kalpesh B.; Chauhan, Jenabhai B.; Barad, Mahesh B.

    2012-01-01

    In the present study, in vitro anticariogenic potential of ethyl acetate, hexane and methanol and aqueous extracts of plant leaves of Eucalyptus globules Labill. were evaluated by using four cariogenic bacteria, Lactobacillus acidophilus, Lactobacillus casei, Staphylococcus aureus and Streptococcus mutans. Agar well diffusion method and minimum inhibitory concentration (MIC) were used for this purpose. The ethyl acetate extracted fraction of plant leaves showed good inhibitory effects against all selected bacteria. In Eucalyptus globules, hexane and ethyl acetate extracts found highly effective against, Lactobacillus acidophilus with MIC value of 0.031 and 0.062 mg/mL, respectively. Qualitative phytochemical investigation of above extracts showed the presence of alkaloids, phenolic compounds, steroids, cardiac glycosides and terpenes. Based on the MIC value and bioautography, ethyl acetate of plant leaf was selected for further study. Further investigation on the structure elucidation of the bioactive compound using IR, GC-MS and NMR techniques revealed the presence of alpha-farnesene, a sesquiterpene. Eucalyptus globules plant leaf extracts have great potential as anticariogenic agents that may be useful in the treatment of oral disease. PMID:23961222

  12. Coffee contains potent opiate receptor binding activity.

    PubMed

    Boublik, J H; Quinn, M J; Clements, J A; Herington, A C; Wynne, K N; Funder, J W

    1983-01-20

    Opiate receptor-active peptide fragments (exorphins) have been identified recently in casein and gluten hydrolysates, and morphine has been found in bovine and human milk. To determine whether similar peptides or alkaloids occur in other foodstuffs, we have screened potential sources using a rat brain homogenate assay to detect opiate receptor activity. We report here that instant coffee powders from a variety of manufacturers compete with tritiated naloxone for binding to opiate receptors in the rat brain membrane preparations, with no significant difference between normal and decaffeinated coffee. The receptor binding activity resembles that seen with opiate antagonists, in that there was no change in the half-maximal effective dose (ED50) in the presence of 100 mM Na+; on bioassay, the activity was similarly shown to be antagonistic and specific for opiate-induced inhibition of twitch. Preliminary characterization of the activity reveals that it has a molecular weight (MW) in the range 1,000-3,500, is heat-stable, ether-extractable, not modified by enzymatic digestion with papain, and clearly separable from caffeine and morphine on TLC. As its concentration in an average cup of coffee is five times the ED50, these data suggest that drinking coffee may be followed by effects mediated via opiate receptors, as well as effects of caffeine.

  13. ANTICARIOGENIC POTENCIAL OF ACIDULATE SOLUTIONS WITH LOW FLUORIDE CONCENTRATION

    PubMed Central

    Delbem, Alberto Carlos Botazzo; Tiano, Gilberto Carlos; Alves, Karina Mirela Ribeiro Pinto; Cunha, Robson Frederico

    2006-01-01

    Objectives: The aim of this study was to verify the anticariogenic effect of acidulate solutions with low NaF concentration, using pH-cycling model and bovine enamel. Material and methods: Enamel blocks were submitted to the surface microhardness (SMH) test and randomly divided in 12 experimental and one placebo groups. The blocks were submitted to pH cycling for 7 days, with daily applications once/day of 0.05% NaF and 0.1% NaF and twice/day of 0.02% NaF solutions. Four different pH: 4.0, 5.0, 6.0 and 7.0 were used. Next, SMH test was again used to determine the surface microhardness percentage change (%SMH). Data obtained for %SMH were homogeneous and passed through variance analyses and Tukey's test (5%) as far as fluoride concentrations and pH. Results: The results showed that pH influenced %SMH in 0.02% NaF and 0.05% NaF solutions with pH 4.0, which had less mineral loss compared to pH 7.0 (p<0.05). The 0.02% NaF - pH 4.0, and 0.05% NaF – pH 7.0 groups showed similar results (p>0.05). A dose-response relationship was observed among the tested solutions, with better anticariogenic effect for the 0.1% NaF solution. Conclusion: The results suggest that the addition of citric acid to acidulate mouth rinses reduce mineral loss. PMID:19089268

  14. Deoxygedunin, a natural product with potent neurotrophic activity in mice.

    PubMed

    Jang, Sung-Wuk; Liu, Xia; Chan, Chi Bun; France, Stefan A; Sayeed, Iqbal; Tang, Wenxue; Lin, Xi; Xiao, Ge; Andero, Raul; Chang, Qiang; Ressler, Kerry J; Ye, Keqiang

    2010-07-13

    Gedunin, a family of natural products from the Indian neem tree, possess a variety of biological activities. Here we report the discovery of deoxygedunin, which activates the mouse TrkB receptor and its downstream signaling cascades. Deoxygedunin is orally available and activates TrkB in mouse brain in a BDNF-independent way. Strikingly, it prevents the degeneration of vestibular ganglion in BDNF -/- pups. Moreover, deoxygedunin robustly protects rat neurons from cell death in a TrkB-dependent manner. Further, administration of deoxygedunin into mice displays potent neuroprotective, anti-depressant and learning enhancement effects, all of which are mediated by the TrkB receptor. Hence, deoxygedunin imitates BDNF's biological activities through activating TrkB, providing a powerful therapeutic tool for treatment of various neurological diseases.

  15. Deoxygedunin, a Natural Product with Potent Neurotrophic Activity in Mice

    PubMed Central

    Jang, Sung-Wuk; Liu, Xia; Chan, Chi Bun; France, Stefan A.; Sayeed, Iqbal; Tang, Wenxue; Lin, Xi; Xiao, Ge; Andero, Raul; Chang, Qiang; Ressler, Kerry J.; Ye, Keqiang

    2010-01-01

    Gedunin, a family of natural products from the Indian neem tree, possess a variety of biological activities. Here we report the discovery of deoxygedunin, which activates the mouse TrkB receptor and its downstream signaling cascades. Deoxygedunin is orally available and activates TrkB in mouse brain in a BDNF-independent way. Strikingly, it prevents the degeneration of vestibular ganglion in BDNF −/− pups. Moreover, deoxygedunin robustly protects rat neurons from cell death in a TrkB-dependent manner. Further, administration of deoxygedunin into mice displays potent neuroprotective, anti-depressant and learning enhancement effects, all of which are mediated by the TrkB receptor. Hence, deoxygedunin imitates BDNF's biological activities through activating TrkB, providing a powerful therapeutic tool for treatment of various neurological diseases. PMID:20644624

  16. Dehydroepiandrosterone Derivatives as Potent Antiandrogens with Marginal Agonist Activity

    DTIC Science & Technology

    2014-07-01

    Summary 3. DATES COVERED 1 JUL 2013 - 30 JUN 2014 4 . TITLE AND SUBTITLE Dehydroepiandrosterone Derivatives as Potent Antiandrogens with... 4 Conclusion…………………………………………………………………………… 5 References……………………………………………………………………………. 6 Appendices...metabolite from dehydroepiandrosterone ( DHEA ) and a precursor of testosterone, has an intrinsic androgenic activity which was not completely antagonized by

  17. Kisameet Clay Exhibits Potent Antibacterial Activity against the ESKAPE Pathogens

    PubMed Central

    Behroozian, Shekooh; Svensson, Sarah L.

    2016-01-01

    ABSTRACT The ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens cause an increasing number of nosocomial infections worldwide since they escape the inhibitory effect of the available antibiotics and the immune response. Here, we report the broad-spectrum and potent antibacterial activity of Kisameet clay, a natural clay mineral from British Columbia, Canada, against a group of multidrug-resistant ESKAPE strains. The results suggest that this natural clay might be developed as a therapeutic option for the treatment of serious infections caused by these important pathogens. PMID:26814180

  18. Plants from Brazilian Cerrado with Potent Tyrosinase Inhibitory Activity

    PubMed Central

    Souza, Paula Monteiro; Elias, Silvia Taveira; Simeoni, Luiz Alberto; de Paula, José Elias; Gomes, Sueli Maria; Guerra, Eliete Neves Silva; Fonseca, Yris Maria; Silva, Elton Clementino; Silveira, Dâmaris; Magalhães, Pérola Oliveira

    2012-01-01

    The increased amount of melanin leads to skin disorders such as age spots, freckles, melasma and malignant melanoma. Tyrosinase is known to be the key enzyme in melanin production. Plants and their extracts are inexpensive and rich resources of active compounds that can be utilized to inhibit tyrosinase as well as can be used for the treatment of dermatological disorders associated with melanin hyperpigmentation. Using in vitro tyrosinase inhibitory activity assay, extracts from 13 plant species from Brazilian Cerrado were evaluated. The results showed that Pouteria torta and Eugenia dysenterica extracts presented potent in vitro tyrosinase inhibition compared to positive control kojic acid. Ethanol extract of Eugenia dysenterica leaves showed significant (p<0.05) tyrosinase inhibitory activity exhibiting the IC50 value of 11.88 µg/mL, compared to kojic acid (IC50 value of 13.14 µg/mL). Pouteria torta aqueous extract leaves also showed significant inhibitory activity with IC50 value of 30.01 µg/mL. These results indicate that Pouteria torta and Eugenia dysenterica extracts and their isolated constituents are promising agents for skin-whitening or antimelanogenesis formulations. PMID:23173036

  19. Novel Gallate Triphenylphosphonium Derivatives with Potent Antichagasic Activity.

    PubMed

    Cortes, Leonel A; Castro, Lorena; Pesce, Bárbara; Maya, Juan D; Ferreira, Jorge; Castro-Castillo, Vicente; Parra, Eduardo; Jara, José A; López-Muñoz, Rodrigo

    2015-01-01

    disease is one of the most neglected tropical diseases in the world, affecting nearly 15 million people, primarily in Latin America. Only two drugs are used for the treatment of this disease, nifurtimox and benznidazole. These drugs have limited efficacy and frequently induce adverse effects, limiting their usefulness. Consequently, new drugs must be found. In this study, we demonstrated the in vitro trypanocidal effects of a series of four gallic acid derivatives characterized by a gallate group linked to a triphenylphosphonium (TPP(+)) moiety (a delocalized cation) via a hydrocarbon chain of 8, 10, 11, or 12 atoms (TPP(+)-C8, TPP(+)-C10, TPP(+)-C11, and TPP(+)-C12, respectively). We analyzed parasite viability in isolated parasites (by MTT reduction and flow cytometry) and infected mammalian cells using T. cruzi Y strain trypomastigotes. Among the four derivatives, TPP(+)-C10 and TPP(+)-C12 were the most potent in both models, with EC50 values (in isolated parasites) of 1.0 ± 0.6 and 1.0 ± 0.7 μM, respectively, and were significantly more potent than nifurtimox (EC50 = 4.1 ± 0.6 μM). At 1 μM, TPP(+)-C10 and TPP(+)-C12 induced markers of cell death, such as phosphatidylserine exposure and propidium iodide permeabilization. In addition, at 1 μM, TPP(+)-C10 and TPP(+)-C12 significantly decreased the number of intracellular amastigotes (TPP(+)-C10: 24.3%, TPP(+)-C12: 19.0% of control measurements, as measured by DAPI staining) and the parasite's DNA load (C10: 10%, C12: 13% of control measurements, as measured by qPCR). Based on the previous mode of action described for these compounds in cancer cells, we explored their mitochondrial effects in isolated trypomastigotes. TPP(+)-C10 and TPP(+)-C12 were the most potent compounds, significantly altering mitochondrial membrane potential at 1 μM (measured by JC-1 fluorescence) and inducing mitochondrial transition pore opening at 5 μM. Taken together, these results indicate that the TPP(+)-C10 and TPP(+)-C12

  20. Novel Gallate Triphenylphosphonium Derivatives with Potent Antichagasic Activity

    PubMed Central

    Cortes, Leonel A.; Castro, Lorena; Pesce, Bárbara; Maya, Juan D.; Ferreira, Jorge; Castro-Castillo, Vicente; Parra, Eduardo; Jara, José A.; López-Muñoz, Rodrigo

    2015-01-01

    Chagas disease is one of the most neglected tropical diseases in the world, affecting nearly 15 million people, primarily in Latin America. Only two drugs are used for the treatment of this disease, nifurtimox and benznidazole. These drugs have limited efficacy and frequently induce adverse effects, limiting their usefulness. Consequently, new drugs must be found. In this study, we demonstrated the in vitro trypanocidal effects of a series of four gallic acid derivatives characterized by a gallate group linked to a triphenylphosphonium (TPP+) moiety (a delocalized cation) via a hydrocarbon chain of 8, 10, 11, or 12 atoms (TPP+-C8, TPP+-C10, TPP+-C11, and TPP+-C12, respectively). We analyzed parasite viability in isolated parasites (by MTT reduction and flow cytometry) and infected mammalian cells using T. cruzi Y strain trypomastigotes. Among the four derivatives, TPP+-C10 and TPP+-C12 were the most potent in both models, with EC50 values (in isolated parasites) of 1.0 ± 0.6 and 1.0 ± 0.7 μM, respectively, and were significantly more potent than nifurtimox (EC50 = 4.1 ± 0.6 μM). At 1 μM, TPP+-C10 and TPP+-C12 induced markers of cell death, such as phosphatidylserine exposure and propidium iodide permeabilization. In addition, at 1 μM, TPP+-C10 and TPP+-C12 significantly decreased the number of intracellular amastigotes (TPP+-C10: 24.3%, TPP+-C12: 19.0% of control measurements, as measured by DAPI staining) and the parasite’s DNA load (C10: 10%, C12: 13% of control measurements, as measured by qPCR). Based on the previous mode of action described for these compounds in cancer cells, we explored their mitochondrial effects in isolated trypomastigotes. TPP+-C10 and TPP+-C12 were the most potent compounds, significantly altering mitochondrial membrane potential at 1 μM (measured by JC-1 fluorescence) and inducing mitochondrial transition pore opening at 5 μM. Taken together, these results indicate that the TPP+-C10 and TPP+-C12 derivatives of gallic acid are

  1. Xenoestrogens are potent activators of nongenomic estrogenic responses

    PubMed Central

    Watson, Cheryl S.; Bulayeva, Nataliya N.; Wozniak, Ann L.; Alyea, Rebecca A.

    2007-01-01

    Studies of the nuclear transcriptional regulatory activities of nonphysiological estrogens have not explained their actions in mediating endocrine disruption in animals and humans at the low concentrations widespread in the environment. However, xenoestrogens have rarely been tested for their ability to participate in the plethora of nongenomic steroid signaling pathways elucidated over the last several years. Here we review what is known about such responses in comparison to our recent evidence that xenoestrogens can rapidly and potently elicit signaling through nongenomic pathways culminating in functional endpoints. Both estradiol (E2) and compounds representing various classes of xenoestrogens (diethylstilbestrol, coumestrol, bisphenol A, DDE, nonylphenol, endosulfan, and dieldrin) act via a membrane version of the estrogen receptor-α on pituitary cells, and can provoke Ca++ influx via L-type channels, leading to prolactin (PRL) secretion. These hormones and mimetics can also cause the oscillating activation of extracellular regulated kinases (ERKs). However, individual estrogen mimetics differ in their potency and temporal phasing of these activations compared to each other and to E2. It is perhaps in these ways that they disrupt some endocrine functions when acting in combination with physiological estrogens. Our quantitative assays allow comparison of these outcomes for each mimetic, and let us build a detailed picture of alternative signaling pathway usage. Such an understanding should allow us to determine the estrogenic or antiestrogenic potential of different types of xenoestrogens, and help us to develop strategies for preventing xenoestrogenic disruption of estrogen action in many tissues. PMID:17174995

  2. Tetrahydrocannabinolic acid is a potent PPARγ agonist with neuroprotective activity.

    PubMed

    Nadal, Xavier; Del Río, Carmen; Casano, Salvatore; Palomares, Belén; Ferreiro-Vera, Carlos; Navarrete, Carmen; Sánchez-Carnerero, Carolina; Cantarero, Irene; Luz Bellido, M; Meyer, Stefan; Morello, Gaetano; Appendino, Giovanni; Muñoz, Eduardo

    2017-08-29

    Phytocannabinoids are produced in Cannabis sativa L. in acidic form and are decarboxylated upon heating, processing, and storage. While the biological effects of decarboxylated cannabinoids such as Δ(9) -tetrahydrocannabinol (Δ(9) -THC) have been extensively investigated, the bioactivity of Δ(9) -THCA is largely unknown, despite its occurrence in different Cannabis preparations. The aim of this study was to determine whether Δ(9) -THCA modulates the PPARγ pathway and has neuroprotective activity EXPERIMENTAL APPROACH: The effects of six phytocannabinoids on PPARγ binding and transcriptional activity were investigated. The effect of Δ(9) -THCA on mitochondrial biogenesis and PGC-1α expression was investigated in N2a cells. The neuroprotective effect was analysed in STHdh(Q111/Q111) cells expressing a mutated form of the huntingtin protein, and in N2a cells infected with an adenovirus carrying human huntingtin containing 94 polyQ repeats (mHtt-q94). In vivo neuroprotective activity of Δ(9) -THCA was investigated in mice intoxicated with the mitochondrial toxin 3-nitropropionic acid (3-NP). Cannabinoid acids bind and activate PPARγ with higher potency than their decarboxylated products. Δ(9) -THCA increases mitochondrial mass in neuroblastoma N2a cells, and prevents cytotoxicity induced by serum deprivation in STHdh(Q111/Q111) cells and by mutHtt-q94 in N2a cells. Δ(9) -THCA, through a PPARγ-dependent pathway, was neuroprotectant in mice intoxicated with 3-NP, improving motor deficits and preventing striatal degeneration. In addition, Δ(9) -THCA attenuated microgliosis, astrogliosis and the upregulation of proinflammatory markers induced by 3-NP. Δ(9) -THCA shows potent neuroprotective activity, worth consideration for the treatment of Huntington´s Disease and possibly other neurodegenerative and neuroinflammatory diseases. This article is protected by copyright. All rights reserved.

  3. Acylthiourea, acylurea, and acylguanidine derivatives with potent hedgehog inhibiting activity.

    PubMed

    Solinas, Antonio; Faure, Hélène; Roudaut, Hermine; Traiffort, Elisabeth; Schoenfelder, Angèle; Mann, André; Manetti, Fabrizio; Taddei, Maurizio; Ruat, Martial

    2012-02-23

    The Smoothened (Smo) receptor is the major transducer of the Hedgehog (Hh) signaling pathway. On the basis of the structure of the acylthiourea Smo antagonist (MRT-10), a number of different series of analogous compounds were prepared by ligand-based structural optimization. The acylthioureas, originally identified as actives, were converted into the corresponding acylureas or acylguanidines. In each series, similar structural trends delivered potent compounds with IC(50) values in the nanomolar range with respect to the inhibition of the Hh signaling pathway in various cell-based assays and of BODIPY-cyclopamine binding to human Smo. The similarity of their biological activities, in spite of discrete structural differences, may reveal the existence of hydrogen-bonding interactions between the ligands and the receptor pocket. Biological potency of compounds 61, 72, and 86 (MRT-83) were comparable to those of the clinical candidate GDC-0449. These findings suggest that these original molecules will help delineate Smo and Hh functions and can be developed as potential anticancer agents.

  4. Potent Anti-Trypanosoma cruzi Activities of Oxidosqualene Cyclase Inhibitors

    PubMed Central

    Buckner, Frederick S.; Griffin, John H.; Wilson, Aaron J.; Van Voorhis, Wesley C.

    2001-01-01

    Trypanosoma cruzi is the protozoan agent that causes Chagas' disease, a major health problem in Latin America. Better drugs are needed to treat infected individuals. The sterol biosynthesis pathway is a potentially excellent target for drug therapy against T. cruzi. In this study, we investigated the antitrypanosomal activities of a series of compounds designed to inhibit a key enzyme in sterol biosynthesis, oxidosqualene cyclase. This enzyme converts 2,3-oxidosqualene to the tetracyclic product, lanosterol. The lead compound, N-(4E,8E)-5,9, 13-trimethyl-4,8, 12-tetradecatrien-1-ylpyridinium, is an electron-poor aromatic mimic of a monocyclized transition state or high-energy intermediate formed from oxidosqualene. This compound and 27 related compounds were tested against mammalian-stage T. cruzi, and 12 inhibited growth by 50% at concentrations below 25 nM. The lead compound was shown to cause an accumulation of oxidosqualene and decreased production of lanosterol and ergosterol, consistent with specific inhibition of the oxidosqualene cyclase. The data demonstrate potent anti-T. cruzi activity associated with inhibition of oxidosqualene cyclase. PMID:11257036

  5. Synthetic galactomannans with potent anti-HIV activity.

    PubMed

    Budragchaa, Davaanyam; Bai, Shiming; Kanamoto, Taisei; Nakashima, Hideki; Han, Shuqin; Yoshida, Takashi

    2015-10-05

    Ring-opening polymerization of a new 1,6-anhydro disaccharide monomer, 1, 6-anhydro-2, 3-di-O-benzyl-4-O-(2', 3', 4', 6'-tetra-O-benzyl-α-d-galactopyranosyl)-α-d-mannopyranose, was carried out using PF5 as a catalyst under high vacuum at -60°C to give galactose branched mannopyranan (synthetic galactomannan), 4-O-α-d-galactopyranosyl-(1→6)-α-d-mannopyranan, after debenzylation with Na in liquid NH3. The ring-opening copolymerization with 1, 6-anhydro-tri-O-benzyl-α-d-mannopyranose in various feeds was also performed to give synthetic galactomannans with various proportions of galactose branches. After sulfation, sulfated synthetic galactomannans were found to have anti-HIV activity and cytotoxicity as high and low as those of standard curdlan and dextran sulfates, respectively, which are potent anti-HIV sulfated polysaccharides with low cytotoxicity. The anti-HIV mechanism of sulfated synthetic galactomannans used by poly-l-lysine as a model peptide of the HIV surface protein was estimated by using SPR, DSL, and zeta potential measurements, revealing the electrostatic interaction between negatively charged sulfate groups and positively charged amino groups.

  6. Kisameet Clay Exhibits Potent Antibacterial Activity against the ESKAPE Pathogens.

    PubMed

    Behroozian, Shekooh; Svensson, Sarah L; Davies, Julian

    2016-01-26

    The ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens cause an increasing number of nosocomial infections worldwide since they escape the inhibitory effect of the available antibiotics and the immune response. Here, we report the broad-spectrum and potent antibacterial activity of Kisameet clay, a natural clay mineral from British Columbia, Canada, against a group of multidrug-resistant ESKAPE strains. The results suggest that this natural clay might be developed as a therapeutic option for the treatment of serious infections caused by these important pathogens. More than 50 years of misuse and overuse of antibiotics has led to a plague of antibiotic resistance that threatens to reduce the efficacy of antimicrobial agents available for the treatment of infections due to resistant organisms. The main threat is nosocomial infections in which certain pathogens, notably the ESKAPE organisms, are essentially untreatable and contribute to increasing mortality and morbidity in surgical wards. The pipeline of novel antimicrobials in the pharmaceutical industry is essentially empty. Thus, there is a great need to seek for new sources for the treatment of recalcitrant infectious diseases. We describe experiments that demonstrate the efficacy of a "natural" medicine, Kisameet clay, against all of the ESKAPE strains. We suggest that this material is worthy of clinical investigation for the treatment of infections due to multidrug-resistant organisms. Copyright © 2016 Behroozian et al.

  7. Potent antitumor activity of a urokinase-activated engineered anthrax toxin

    NASA Astrophysics Data System (ADS)

    Liu, Shihui; Aaronson, Hannah; Mitola, David J.; Leppla, Stephen H.; Bugge, Thomas H.

    2003-01-01

    The acquisition of cell-surface urokinase plasminogen activator activity is a hallmark of malignancy. We generated an engineered anthrax toxin that is activated by cell-surface urokinase in vivo and displays limited toxicity to normal tissue but broad and potent tumoricidal activity. Native anthrax toxin protective antigen, when administered with a chimeric anthrax toxin lethal factor, Pseudomonas exotoxin fusion protein, was extremely toxic to mice, causing rapid and fatal organ damage. Replacing the furin activation sequence in anthrax toxin protective antigen with an artificial peptide sequence efficiently activated by urokinase greatly attenuated toxicity to mice. In addition, the mutation conferred cell-surface urokinase-dependent toxin activation in vivo, as determined by using a panel of plasminogen, plasminogen activator, plasminogen activator receptor, and plasminogen activator inhibitor-deficient mice. Surprisingly, toxin activation critically depended on both urokinase plasminogen activator receptor and plasminogen in vivo, showing that both proteins are essential cofactors for the generation of cell-surface urokinase. The engineered toxin displayed potent tumor cell cytotoxicity to a spectrum of transplanted tumors of diverse origin and could eradicate established solid tumors. This tumoricidal activity depended strictly on tumor cell-surface plasminogen activation. The data show that a simple change of protease activation specificity converts anthrax toxin from a highly lethal to a potent tumoricidal agent.

  8. Dehydroepiandrosterone Derivatives as Potent Antiandrogens with Marginal Agonist Activity

    DTIC Science & Technology

    2010-07-01

    or 9), although these compounds still showed anti-DHT effects (lanes 2 vs. 6, 8, or 10). Figure 4 . The effects of DHEA derivatives on PSA...2009 - 30 JUN 2010 4 . TITLE AND SUBTITLE Dehydroepiandrosterone Derivatives as Potent Antiandrogens 5a. CONTRACT NUMBER with Marginal Agonist...words) We hypothesized that dehydroepiandrosterone ( DHEA ) metabolites or their synthetic derivatives are able to bind to the androgen receptor with

  9. Dehydroepiandrosterone Derivatives as Potent Antiandrogens with Marginal Agonist Activity

    DTIC Science & Technology

    2013-07-01

    DATES COVERED 01 July 2012 – 30 June 2013 4 . TITLE AND SUBTITLE Dehydroepiandrosterone Derivatives as Potent Antiandrogens with Marginal Agonist...Page Introduction…………………………………………………………….………..….. 1 Body………………………………………………………………………………….. 1- 4 Key Research...In addition, we previously found that androstenediol (Adiol), a physiological metabolite from dehydroepiandrosterone ( DHEA ) and a precursor of

  10. Potent Antimicrobial activity of Lipidated Short alpha, gamma-hybrid peptides.

    PubMed

    Benke, Sushil; Thulasiram, Hirekodathakallu; Gopi, Hosahudya

    2017-08-18

    We are reporting potent antimicrobial activity of alpha,gamma-hybrid lipopeptides constituted with 1:1 alternating alpha- and gamma-amino acids. Along with their potent antimicrobial activity against various Gram positive and Gram negative bacteria, these hybrid lipopeptides were found to be less haemolytic. The mechanism of action revealed that these short cationic lipopeptides bind and disrupt the bacterial cell membrane. Further, the time kill kinetics analysis revealed that the potent alpha,gamma-hybrid lipopeptides completely inhibit the bacterial growth in less than 20 minutes. Overall, the promising antimicrobial activity along with less haemolytic activity displayed by the alpha,gamma-hybrid lipopeptides can be further explored to design potent lipopeptide antibiotics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Synthesis and evaluation of 2,4-disubstituted quinazoline derivatives with potent anti-angiogenesis activities.

    PubMed

    Yu, Guangjin; Li, Zeng; Tang, Liang; Xiong, Qiru

    2014-06-26

    A series of 2,4-disubstituted quinazoline derivatives were designed and synthesized. The biological results showed that most of quinazoline derivatives exhibited potent antiproliferative activities against a panel of three tumor cell lines and a good inhibitory effect against the adhesion and migration of human umbilical vein endothelial cells (HUVECs). Among these compounds, 11d was the most potent agent, that also exhibited the highest anti-angiogenesis activities in the chick embryo chorioallantoic membrane (CAM) assay.

  12. The Potent Oxidant Anticancer Activity of Organoiridium Catalysts**

    PubMed Central

    Liu, Zhe; Romero-Canelón, Isolda; Qamar, Bushra; Hearn, Jessica M; Habtemariam, Abraha; Barry, Nicolas P E; Pizarro, Ana M; Clarkson, Guy J; Sadler, Peter J

    2014-01-01

    Platinum complexes are the most widely used anticancer drugs; however, new generations of agents are needed. The organoiridium(III) complex [(η5-Cpxbiph)Ir(phpy)(Cl)] (1-Cl), which contains π-bonded biphenyltetramethylcyclopentadienyl (Cpxbiph) and C∧N-chelated phenylpyridine (phpy) ligands, undergoes rapid hydrolysis of the chlorido ligand. In contrast, the pyridine complex [(η5-Cpxbiph)Ir(phpy)(py)]+ (1-py) aquates slowly, and is more potent (in nanomolar amounts) than both 1-Cl and cisplatin towards a wide range of cancer cells. The pyridine ligand protects 1-py from rapid reaction with intracellular glutathione. The high potency of 1-py correlates with its ability to increase substantially the level of reactive oxygen species (ROS) in cancer cells. The unprecedented ability of these iridium complexes to generate H2O2 by catalytic hydride transfer from the coenzyme NADH to oxygen is demonstrated. Such organoiridium complexes are promising as a new generation of anticancer drugs for effective oxidant therapy. PMID:24616129

  13. Halogenated pyrrolopyrimidine analogues of adenosine from marine organisms: pharmacological activities and potent inhibition of adenosine kinase.

    PubMed

    Davies, L P; Jamieson, D D; Baird-Lambert, J A; Kazlauskas, R

    1984-02-01

    Two novel halogenated pyrrolopyrimidine analogues of adenosine, isolated from marine sources, have been examined for pharmacological and biochemical activities. 4-Amino-5-bromo-pyrrolo[2,3-d]pyrimidine, from a sponge of the genus Echinodictyum, had bronchodilator activity at least as potent as theophylline but with a different biochemical profile; unlike theophylline it had no antagonist activity at CNS adenosine receptors and it was quite a potent inhibitor of adenosine uptake and adenosine kinase in brain tissue. 5'-Deoxy-5-iodotubercidin, isolated from the red alga Hypnea valentiae, caused potent muscle relaxation and hypothermia when injected into mice. This compound was a very potent inhibitor of adenosine uptake into rat and guinea-pig brain slices and an extremely potent inhibitor of adenosine kinase from guinea-pig brain and rat brain and liver. Neither of these two pyrrolopyrimidine analogues was a substrate for, or an inhibitor of, adenosine deaminase. Neither compound appeared to have any direct agonist activity on guinea-pig brain adenosine-stimulated adenylate cyclase (A2 adenosine receptors). 5'-Deoxy-5-iodotubercidin is unique in two respects: it appears to be the first naturally-occurring example of a 5'-deoxyribosyl nucleoside and is the first example of a specifically iodinated nucleoside from natural sources. It may be the most potent adenosine kinase inhibitor yet described and, by virtue of its structure, may prove to be the most specific.

  14. Dehydroepiandrosterone Derivatives as Potent Antiandrogens With Marginal Agonist Activity

    DTIC Science & Technology

    2011-07-01

    physiological metabolite from dehydroepiandrosterone ( DHEA ) and a precursor of testosterone, has an intrinsic androgenic activity which was not...antiandrogenic compounds with marginal androgenic activities need to be identified. Our hypothesis in the current project was that DHEA metabolites or their...ones. We previously screened DHEA derivatives/metabolites for their androgenic and antiandrogenic activities and found that three compounds, 3β

  15. Dehydroepiandrosterone Derivatives as Potent Antiandrogens with Marginal Agonist Activity

    DTIC Science & Technology

    2012-07-01

    a physiological metabolite from dehydroepiandrosterone ( DHEA ) and a precursor of testosterone, has an intrinsic androgenic activity which was not...antiandrogenic compounds with marginal androgenic activities need to be identified. Our hypothesis in the current project was that DHEA metabolites or...available ones. We previously screened DHEA derivatives/metabolites for their androgenic and antiandrogenic activities and found that three compounds, 3β

  16. Optimization of 5-pyridazin-3-one phenoxypropylamines as potent, selective histamine H₃ receptor antagonists with potent cognition enhancing activity.

    PubMed

    Tao, Ming; Aimone, Lisa D; Huang, Zeqi; Mathiasen, Joanne; Raddatz, Rita; Lyons, Jacquelyn; Hudkins, Robert L

    2012-01-12

    Previous studies have shown that (5-{4-[3-(R)-2-methylpyrrolin-1-yl-propoxy]phenyl}-2H-pyridazin-3-one) 2 had high affinity for both the human (hH(3)R K(i) = 2.8 nM) and rat H(3)Rs (rH(3)R K(i) = 8.5 nM) but displayed low oral bioavailability in the rat. Optimization of the 5-pyridazin-3-one R(2) and R(6) positions to improve the pharmacokinetic properties over 2 led to the identification of 5-{4-[3-(R)-2-methylpyrrolidin-1-yl)propoxy]phenyl}-2-pyridin-2-yl-2H-pyridazin-3-one 29. Compound 29 displayed high affinity for both human and rat H(3)Rs (hH(3)R K(i) = 1.7 nM, rH(3)R K(i) = 3.7 nM) with a greater than 1000-fold selectivity over the other histamine receptor subtypes and favorable pharmacokinetic properties across species (F = 78% rat, 92% dog, 96% monkey). It showed low binding to human plasma proteins, weakly inhibited cytochrome P450 isoforms, and displayed an excellent safety profile for a CNS-active compound. 29 displayed potent H(3)R antagonist activity in the brain in a rat dipsogenia model and demonstrated enhancement of cognitive function in a rat social recognition model at low doses. However, the development of compound 29 was discontinued because of genotoxicity.

  17. Anticariogenic and antibacterial properties of a copper varnish using an in vitro microbial caries model.

    PubMed

    Thneibat, Amenah; Fontana, Margherita; Cochran, Michael A; Gonzalez-Cabezas, Carlos; Moore, B Keith; Matis, Bruce A; Lund, Melvin R

    2008-01-01

    The antimicrobial and anticariogenic properties of a copper varnish (experimental mixture of Doc's Best Red Copper cement and Copalite varnish, Cooley and Cooley, Ltd, Houston, TX, USA: designated in this study as "Copper Seal") on the root surface were evaluated in an in vitro microbial caries model. Fifty-six human root specimens were prepared from anterior teeth and randomly divided into four groups: Groups 1 and 3-Copper Seal; Group 2-chlorhexidine varnish, the positive control (Cervitec, Ivolcar Vivadent, Schaan, Liechtenstein) and Group 4-a negative control that received no treatment. The varnishes were painted in Groups 1, 2 and 3, then visually removed after 24 hours in Group 1. The specimens were demineralized in a microbial caries model for five days. Plaque was collected from the specimens to obtain bacterial colonization numbers, then the specimens were sectioned and analyzed for lesion extent using Confocal Laser Scanning microscopy. There were no significant differences (p>0.05) among the four groups in terms of bacterial count. Regarding caries lesion development, the group with copper varnish visually removed (Group 1) and the non-treated group (Group 4) had significantly greater total area caries lesions and total lesion fluorescence than the copper varnish without removal group (Group 3) and the chlorhexidine group (Group 2). Therefore, it was concluded that copper and chlorhexidine varnishes have anticariogenic effects on root surfaces, as tested in this model.

  18. Synthesis and antibacterial activity of a novel series of potent DNA gyrase inhibitors. Pyrazole derivatives.

    PubMed

    Tanitame, Akihiko; Oyamada, Yoshihiro; Ofuji, Keiko; Fujimoto, Mika; Iwai, Noritaka; Hiyama, Yoichi; Suzuki, Kenji; Ito, Hideaki; Terauchi, Hideo; Kawasaki, Motoji; Nagai, Kazuo; Wachi, Masaaki; Yamagishi, Jun-ichi

    2004-07-01

    We have previously found that a pyrazole derivative 1 possesses antibacterial activity and inhibitory activity against DNA gyrase and topoisomerase IV. Here, we synthesized new pyrazole derivatives and found that 5-[(E)-2-(5-chloroindol-3-yl)vinyl]pyrazole 16 possesses potent antibacterial activity and selective inhibitory activity against bacterial topoisomerases. Many of the synthesized pyrazole derivatives were potent against clinically isolated quinolone- or coumarin-resistant Gram-positive strains and had minimal inhibitory concentration values against these strains equivalent to those against susceptible strains.

  19. Design, synthesis and potent cytotoxic activity of novel podophyllotoxin derivatives.

    PubMed

    Li, Wen-Qun; Wang, Xu-Li; Qian, Keduo; Liu, Ying-Qian; Wang, Chih-Ya; Yang, Liu; Tian, Jin; Morris-Natschke, Susan L; Zhou, Xing-Wen; Lee, Kuo-Hsiung

    2013-04-15

    Twenty new acyl thiourea derivatives of podophyllotoxin and 4'-demethylepipodophyllotoxin were prepared and screened for their cytotoxicity against four human tumor cell lines, A-549, DU-145, KB, and KBvin. With IC50 values of 0.098-1.13 μM, compounds 13b, 13c, and 13o displayed much better cytotoxic activity than the control etoposide. Most importantly, 13b and 13o exhibited promising cytotoxicity against the drug resistant tumor cell line KBvin with IC50 values of 0.098 and 0.13 μM, respectively, while etoposide lost activity completely. Structure-activity relationship (SAR) correlations of the new derivatives have been established. Compounds 13b and 13o merit further development as a new generation of epipodophyllotoxin-derived antitumor clinical trial candidates.

  20. Potent antihepatotoxic activity of dicaffeoyl quinic acids from propolis.

    PubMed

    Basnet, P; Matsushige, K; Hase, K; Kadota, S; Namba, T

    1996-04-01

    Hepatoprotective activity guided chemical analyses led to the isolation of two dicaffeoyl quinic acid derivatives, methyl 3,4-di-O-caffeoyl quinate (1) and 3,4-di-O-caffeoyl quinic acid (2) from water extract of propolis, and their structures were determined by the use of 2D NMR. These compounds were stronger antihepatotoxic agents than glycyrrhizin.

  1. Anticariogenic potentials of clove, tobacco and bitter kola.

    PubMed

    Uju, Dibua Esther; Obioma, Nnamani Petra

    2011-10-01

    13 Gram-negative and 18 Gram-positive organisms. The n-hexane extract had the best antimicrobial activity followed by the ethanol and lastly hot water. MIC showed that n-hexane clove extract had the largest inhibition zone diameter, followed by bitter kola extract and lastly tobacco extract. The antibiotic sensitivity test credited ciprofloxacin the best because it exhibited broad spectrum of action. Since the n-hexane extract of clove seeds demonstrated preferential growth-inhibitory activity against the causal cariogenic pathogens (S. mutans) in dental caries, we therefore, report here that clove extract be henceforth considered as a potential ingredient in toothpaste preparation. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  2. Biological Activities of Fusarochromanone: a Potent Anti-cancer Agent

    DTIC Science & Technology

    2014-09-03

    Univ. of Texas- MD Anderson Cancer Center), MCF-7 (low malignant mammary gland adenocarcinoma), MDA-231 (malignant mammary gland adenocarcinoma), SV...differences between the groups of mice in terms of tumor volume or persisting benign cysts was compared using the Mann–Whitney test and differences...has modest in-vivo activity. In a mouse xenograft skin SCC tumor model, FC101 was well tolerated and non-toxic, but it required a dose of 8 mg/kg/day

  3. Potent lipolytic activity of lactoferrin in mature adipocytes.

    PubMed

    Ono, Tomoji; Fujisaki, Chikako; Ishihara, Yasuharu; Ikoma, Keiko; Morishita, Satoru; Murakoshi, Michiaki; Sugiyama, Keikichi; Kato, Hisanori; Miyashita, Kazuo; Yoshida, Toshihide; Nishino, Hoyoku

    2013-01-01

    Lactoferrin (LF) is a multifunctional glycoprotein found in mammalian milk. We have shown in a previous clinical study that enteric-coated bovine LF tablets decreased visceral fat accumulation. To address the underlying mechanism, we conducted in vitro studies and revealed the anti-adipogenic action of LF in pre-adipocytes. The aim of this study was to assess whether LF could increase the lipolytic activity in mature adipocytes. Pre-adipocytes were prepared from rat mesenteric fat and differentiated into mature adipocytes for assays of lipolysis. The addition of LF significantly increased the glycerol concentration in the medium in a dose-dependent manner, whereas pepsin-degraded LF did not. A DNA microarray analysis demonstrated that LF decreased the expression of perilipin and affected the cAMP pathway. These findings are supported by the results of quantitative RT-PCR of perilipin and assays of cAMP. These data collectively indicate that visceral fat reduction by LF may result from the promotion of lipolysis and the additional anti-adipogenic activity of LF.

  4. Nobiletin: a citrus flavonoid displaying potent physiological activity.

    PubMed

    Noguchi, Shuji; Atsumi, Haruka; Iwao, Yasunori; Kan, Toshiyuki; Itai, Shigeru

    2016-02-01

    Nobiletin [systematic name: 2-(3,4-dimethoxyphenyl)-5,6,7,8-tetramethoxy-4H-chromen-4-one; C21H22O8] is a flavonoid found in citrus peels, and has been reported to show a wide range of physiological properties, including anti-inflammatory, anticancer and antidementia activities. We have solved the crystal structure of nobiletin, which revealed that the chromene and arene rings of its flavone moiety, as well as the two methoxy groups bound to its arene ring, were coplanar. In contrast, the C atoms of the four methoxy groups bound to the chromene ring are out of the plane, making the molecule conformationally chiral. A comparison of the crystal structures of nobiletin revealed that it could adopt a variety of different conformations through rotation of the covalent bond between the chromene and arene rings, and the orientations of methoxy groups bound to the chromene ring.

  5. Potent Antimalarial Activity of Acriflavine In Vitro and In Vivo

    PubMed Central

    2015-01-01

    Malaria continues to be a major health problem globally. There is an urgent need to find new antimalarials. Acriflavine (ACF) is known as an antibacterial agent and more recently as an anticancer agent. Here, we report that ACF inhibits the growth of asexual stages of both chloroquine (CQ) sensitive and resistant strains of human malarial parasite, Plasmodium falciparum in vitro at nanomolar concentration. ACF clears the malaria infection in vivo from the bloodstreams of mice infected with Plasmodium berghei. Interestingly, ACF is accumulated only in the parasitized red blood cells (RBCs) and parasite specific transporters may have role in this specific drug accumulation. We further show that ACF impairs DNA replication foci formation in the parasites and affects the enzymatic activities of apicoplast specific Gyrase protein. We thus establish ACF as a potential antimalarial amidst the widespread incidences of drug resistant Plasmodium strains. PMID:25089658

  6. Potent cough suppression by physiologically active substance in human plasma.

    PubMed

    Akaike, Norio; Ito, Yushi; Ogawa, Sachie K; Maeda, Megumi; Wakita, Masahito; Takahama, Kazuo; Noguchi, Tetsuro; Kamei, Shintaro; Hamamoto, Takayoshi; Umehashi, Misako; Maeda, Hiroaki

    2014-01-01

    Human plasma contains wide variety of bioactive proteins that have proved essential in therapeutic discovery. However many human plasma proteins remain orphans with unknown biological functions. Evidences suggest that some plasma components target the respiratory system. In the present study we adapted heparin affinity chromatography to fractionate human plasma for functional bioassay. Fractions from pooled human plasma yielded particular plasma fractions with strong cough suppressing effects. Purification yielded a fraction that was finally identified as an activated blood coagulation factor fXIa using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI/TOF-MS). The fraction almost completely suppressed coughs induced by either chemical or mechanical stimulation applied to larynx or bifurcation of guinea-pig trachea. Cough suppressing effect of the fraction and commercially available fXIa were one million times stronger than codeine and codeine only partially suppressed the mechanically triggered coughing in animal model. Recent reviews highlighted prominent shortcomings of current available antitussives, including narcotic opioids such as codeine and their unpleasant or intolerable side effects. Therefore, safer and more effective cough suppressants would be welcome, and present findings indicate that fXIa in human plasma as a very promising, new therapeutic candidate for effective antitussive action.

  7. Cerecidins, Novel Lantibiotics from Bacillus cereus with Potent Antimicrobial Activity

    PubMed Central

    Wang, Jian; Zhang, Li; Teng, Kunling; Sun, Shutao; Sun, Zhizeng

    2014-01-01

    Lantibiotics are ribosomally synthesized and posttranslationally modified antimicrobial peptides that are widely produced by Gram-positive bacteria, including many species of the Bacillus group. In the present study, one novel gene cluster coding lantibiotic cerecidins was unveiled in Bacillus cereus strain As 1.1846 through genomic mining and PCR screening. The designated cer locus is different from that of conventional class II lantibiotics in that it included seven tandem precursor cerA genes, one modification gene (cerM), two processing genes (cerT and cerP), one orphan regulator gene (cerR), and two immunity genes (cerF and cerE). In addition, one unprecedented quorum sensing component, comQXPA, was inserted between cerM and cerR. The expression of cerecidins was not detected in this strain of B. cereus, which might be due to repressed transcription of cerM. We constitutively coexpressed cerA genes and cerM in Escherichia coli, and purified precerecidins were proteolytically processed with the endoproteinase GluC and a truncated version of putative serine protease CerP. Thus, two natural variants of cerecidins A1 and A7 were obtained which contained two terminal nonoverlapping thioether rings rarely found in lantibiotics. Both cerecidins A1 and A7 were active against a broad spectrum of Gram-positive bacteria. Cerecidin A7, especially its mutant Dhb13A, showed remarkable efficacy against multidrug-resistant Staphylococcus aureus (MDRSA), vancomycin-resistant Enterococcus faecalis (VRE), and even Streptomyces. PMID:24532070

  8. Retroviral nucleocapsid proteins possess potent nucleic acid strand renaturation activity.

    PubMed Central

    Dib-Hajj, F.; Khan, R.; Giedroc, D. P.

    1993-01-01

    The nucleocapsid protein (NC) is the major genomic RNA binding protein that plays integral roles in the structure and replication of all animal retroviruses. In this report, select biochemical properties of recombinant Mason-Pfizer monkey virus (MPMV) and HIV-1 NCs are compared. Evidence is presented that two types of saturated Zn2 NC-polynucleotide complexes can be formed under conditions of low [NaCl] that differ in apparent site-size (n = 8 vs. n = 14). The formation of one or the other complex appears dependent on the molar ratio of NC to RNA nucleotide with the putative low site-size mode apparently predominating under conditions of protein excess. Both MPMV and HIV-1 NCs kinetically facilitate the renaturation of two complementary DNA strands, suggesting that this is a general property of retroviral NCs. NC proteins increase the second-order rate constant for renaturation of a 149-bp DNA fragment by more than four orders of magnitude over that obtained in the absence of protein at 37 degrees C. The protein-assisted rate is 100-200-fold faster than that obtained at 68 degrees C, 1 M NaCl, solution conditions considered to be optimal for strand renaturation. Provided that sufficient NC is present to coat all strands, the presence of 400-1,000-fold excess nonhomologous DNA does not greatly affect the reaction rate. The HIV-1 NC-mediated renaturation reaction functions stoichiometrically, requiring a saturated strand of DNA nucleotide:NC ratio of about 7-8, rather than 14. Under conditions of less protein, the rate acceleration is not realized. The finding of significant nucleic acid strand renaturation activity may have important implications for various events of reverse transcription particularly in initiation and cDNA strand transfer. PMID:8443601

  9. Cerecidins, novel lantibiotics from Bacillus cereus with potent antimicrobial activity.

    PubMed

    Wang, Jian; Zhang, Li; Teng, Kunling; Sun, Shutao; Sun, Zhizeng; Zhong, Jin

    2014-04-01

    Lantibiotics are ribosomally synthesized and posttranslationally modified antimicrobial peptides that are widely produced by Gram-positive bacteria, including many species of the Bacillus group. In the present study, one novel gene cluster coding lantibiotic cerecidins was unveiled in Bacillus cereus strain As 1.1846 through genomic mining and PCR screening. The designated cer locus is different from that of conventional class II lantibiotics in that it included seven tandem precursor cerA genes, one modification gene (cerM), two processing genes (cerT and cerP), one orphan regulator gene (cerR), and two immunity genes (cerF and cerE). In addition, one unprecedented quorum sensing component, comQXPA, was inserted between cerM and cerR. The expression of cerecidins was not detected in this strain of B. cereus, which might be due to repressed transcription of cerM. We constitutively coexpressed cerA genes and cerM in Escherichia coli, and purified precerecidins were proteolytically processed with the endoproteinase GluC and a truncated version of putative serine protease CerP. Thus, two natural variants of cerecidins A1 and A7 were obtained which contained two terminal nonoverlapping thioether rings rarely found in lantibiotics. Both cerecidins A1 and A7 were active against a broad spectrum of Gram-positive bacteria. Cerecidin A7, especially its mutant Dhb13A, showed remarkable efficacy against multidrug-resistant Staphylococcus aureus (MDRSA), vancomycin-resistant Enterococcus faecalis (VRE), and even Streptomyces.

  10. The sGC activator BAY 60-2770 has potent erectile activity in the rat.

    PubMed

    Lasker, George F; Pankey, Edward A; Frink, Terrence J; Zeitzer, Jonathan R; Walter, Korey A; Kadowitz, Philip J

    2013-06-15

    Nitric oxide (NO) is the principal mediator of penile erection, and soluble guanylate cyclase (sGC) is the receptor for NO. In pathophysiological conditions when sGC is inactivated and not responsive to NO or sGC stimulators a new class of agents called sGC activators increase the activity of NO-insensitive sGC and produce erection. The aim of this study was to investigate erectile responses to BAY 60-2770, a sGC activator, under physiological and pathophysiological conditions. In the present study increases in intracavernosal pressure (ICP) in response to intracavernosal (ic) injections of BAY 60-2770 were investigated under baseline conditions, when sGC was inhibited by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), when nitric oxide synthase (NOS) was inhibited by N-nitro-L-arginine methyl ester (L-NAME), and after cavernosal nerve crush injury. Under baseline conditions ic injections of BAY 60-2770 increase ICP, ICP/mean arterial pressure (MAP), and area under the ICP curve (AUC) and produce small decreases in MAP at the highest doses studied. BAY 60-2770 was very potent in its ability to induce erection and responses to BAY 60-2770 were enhanced by ODQ which attenuates erectile responses to sodium nitroprusside (SNP), diethylamine NONOate (DEA/NO), and cavernosal nerve stimulation. Responses to BAY 60-2770 were not altered by L-NAME or cavernosal nerve crush injury. These data indicate that BAY 60-2770 has potent erectile activity that is enhanced by ODQ and show that responses to BAY 60-2770 are not attenuated by NOS inhibition or cavernosal nerve injury. These results suggest that BAY 60-2770 would be effective in the treatment of erectile dysfunction when NO bioavailability is reduced, after pelvic nerve injury, and when sGC is oxidized.

  11. The sGC activator BAY 60-2770 has potent erectile activity in the rat

    PubMed Central

    Lasker, George F.; Pankey, Edward A.; Frink, Terrence J.; Zeitzer, Jonathan R.; Walter, Korey A.

    2013-01-01

    Nitric oxide (NO) is the principal mediator of penile erection, and soluble guanylate cyclase (sGC) is the receptor for NO. In pathophysiological conditions when sGC is inactivated and not responsive to NO or sGC stimulators a new class of agents called sGC activators increase the activity of NO-insensitive sGC and produce erection. The aim of this study was to investigate erectile responses to BAY 60-2770, a sGC activator, under physiological and pathophysiological conditions. In the present study increases in intracavernosal pressure (ICP) in response to intracavernosal (ic) injections of BAY 60-2770 were investigated under baseline conditions, when sGC was inhibited by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), when nitric oxide synthase (NOS) was inhibited by N-nitro-l-arginine methyl ester (l-NAME), and after cavernosal nerve crush injury. Under baseline conditions ic injections of BAY 60-2770 increase ICP, ICP/mean arterial pressure (MAP), and area under the ICP curve (AUC) and produce small decreases in MAP at the highest doses studied. BAY 60-2770 was very potent in its ability to induce erection and responses to BAY 60-2770 were enhanced by ODQ which attenuates erectile responses to sodium nitroprusside (SNP), diethylamine NONOate (DEA/NO), and cavernosal nerve stimulation. Responses to BAY 60-2770 were not altered by l-NAME or cavernosal nerve crush injury. These data indicate that BAY 60-2770 has potent erectile activity that is enhanced by ODQ and show that responses to BAY 60-2770 are not attenuated by NOS inhibition or cavernosal nerve injury. These results suggest that BAY 60-2770 would be effective in the treatment of erectile dysfunction when NO bioavailability is reduced, after pelvic nerve injury, and when sGC is oxidized. PMID:23585129

  12. Potent complement C3a receptor agonists derived from oxazole amino acids: Structure-activity relationships.

    PubMed

    Singh, Ranee; Reed, Anthony N; Chu, Peifei; Scully, Conor C G; Yau, Mei-Kwan; Suen, Jacky Y; Durek, Thomas; Reid, Robert C; Fairlie, David P

    2015-12-01

    Potent ligands for the human complement C3a receptor (C3aR) were developed from the almost inactive tripeptide Leu-Ala-Arg corresponding to the three C-terminal residues of the endogenous peptide agonist C3a. The analogous Leu-Ser-Arg was modified by condensing the serine side chain with the leucine carbonyl with elimination of water to form leucine-oxazole-arginine. Subsequent elaboration with a variety of N-terminal amide capping groups produced agonists as potent as human C3a itself in stimulating Ca(2+) release from human macrophages. Structure-activity relationships are discussed.

  13. Discovery of highly selective 7-chloroquinoline-thiohydantoins with potent antimalarial activity.

    PubMed

    Raj, Raghu; Mehra, Vishu; Gut, Jiri; Rosenthal, Philip J; Wicht, Kathryn J; Egan, Timothy J; Hopper, Melissa; Wrischnik, Lisa A; Land, Kirkwood M; Kumar, Vipan

    2014-09-12

    A series of C-3 thiourea functionalized β-lactams, β-lactam-7-chloroquinoline conjugates and 7-chloroquinoline-thiohydantoin derivatives were prepared with the aim of probing antimalarial structure-activity relationships. 7-Chlorquinoline-thiohydantoin derivatives were found to be potent inhibitors of cultured Plasmodium falciparum, with the most potent and non-cytotoxic compound exhibiting an IC50 of 39.8 nM. Studies of β-hematin formation suggested that inhibition of haemozoin formation could be primary mechanism of action, with IC50 values comparable to those of chloroquine. Evaluation of cytotoxicity against HeLa cells demonstrated high selective indices.

  14. Discovery of indole-based tetraarylimidazoles as potent inhibitors of urease with low antilipoxygenase activity.

    PubMed

    Naureen, Sadia; Chaudhry, Faryal; Asif, Nadia; Munawar, Munawar Ali; Ashraf, Muhammad; Nasim, Faizul Hassan; Arshad, Humera; Khan, Misbahul Ain

    2015-09-18

    A series of tetraarylimidazoles (5A-5O) were prepared by one pot four component condensation reactions of 2-arylindole-3-carbaldehydes, substituted anilines, benzil and ammonium acetate in acetic acid. The synthesized compounds exhibited potent antiurease activity with IC50 values ranging from 0.12 ± 0.06 μM to 29.12 ± 0.18 μM as compared with thiourea. However, low inhibition profiles were observed for lipoxygenase. The data show that tetraarylimidazoles containing a substituted 2-penylindole have emerged as a new class of potent inhibitors of urease enzyme.

  15. METHYLATION INACTIVATES PENTAVALENT ARSENIC SPECIES BUT ACTIVATES TRIVALENT ARSENIC SPECIES TO POTENT GENOTOXICANTS

    EPA Science Inventory

    Methylation Inactivates Pentavalent Arsenic Species but Activates Trivalent Arsenic Species to Potent Genotoxicants

    The sensitivity ofhumans to arsenic-induced cancer is thought to be related in part to the limited ability of humans to detoxify arsenic. Recently, methyl- ...

  16. Tear gasses CN, CR, and CS are potent activators of the human TRPA1 receptor

    SciTech Connect

    Brone, Bert; Peeters, Pieter J.; Marrannes, Roger; Mercken, Marc; Nuydens, Ronny; Meert, Theo; Gijsen, Harrie J.M.

    2008-09-01

    The TRPA1 channel is activated by a number of pungent chemicals, such as allylisothiocyanate, present in mustard oil and thiosulfinates present in garlic. Most of the known activating compounds contain reactive, electrophilic chemical groups, reacting with cysteine residues in the active site of the TRPA1 channel. This covalent modification results in activation of the channel and has been shown to be reversible for several ligands. Commonly used tear gasses CN, CR and CS are also pungent chemicals, and in this study we show that they are extremely potent and selective activators of the human TRPA1 receptor. To our knowledge, these are the most potent TRPA1 agonists known to date. The identification of the molecular target for these tear gasses may open up possibilities to alleviate the effects of tear gasses via treatment with TRPA1 antagonists. In addition these results may contribute to the basic knowledge of the TRPA1 channel that is gaining importance as a pharmacological target.

  17. Novel derivatives of phthalimide with potent anticonvulsant activity in PTZ and MES seizure models.

    PubMed

    Davood, Asghar; Iman, Maryam; Pouriaiee, Hanieh; Shafaroodi, Hamed; Akhbari, Sepideh; Azimidoost, Leila; Imani, Erfan; Rahmatpour, Somaieh

    2017-04-01

    Phthalimide-based derivatives have anticonvulsant activity like as phenytoin by inhibition of sodium channel. In our previously research we mentioned about some phthalimide derivatives as potent anticonvulsant agents. Fourteen analogs of 2-substituted phthalimide pharmacophore were synthesized and then were evaluated for the anticonvulsant activities in pentylenetetrazole-induced seizures (PTZ) and maximal electroshock seizure (MES) models. The in vivo screening results showed that all the analogs have the ability to protect against the maximal electroshock and PTZ. The compounds 3 and 9 elevated clonic seizure thresholds at 30 min which were more active than the standard medicine phenytoin. Compounds 3, 6, 7, 11, 13 and 14 with 100% protection were the most potent ones in tonic seizure. The most potent compound in the both PTZ and MES models was compound 3. Using a model of the open pore of sodium channel, all of the compounds were docked. Results of docking showed that the ligands interacted mainly with residues II-S6 of NaV1.2 by making hydrogen bonds and have additional hydrophobic interactions with other domains in the channel's inner pore. Some of these compounds are more potent than phenytoin simultaneously in the clonic and tonic seizures.

  18. Metofluthrin: a potent new synthetic pyrethroid with high vapor activity against mosquitoes.

    PubMed

    Ujihara, Kazuya; Mori, Tatsuya; Iwasaki, Tomonori; Sugano, Masayo; Shono, Yoshinori; Matsuo, Noritada

    2004-01-01

    (1R)-trans-Norchrysanthemic acid fluorobenzyl esters are synthesized and their structure-activity relationships are discussed. These esters show outstanding insecticidal activity against mosquitoes. In particular, the 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl analog (metofluthrin) exhibits the highest potency, being approximately forty times as potent as d-allethrin in a mosquito coil formulation when tested against southern house mosquitoes (Culex quinquefasciatus). Metofluthrin also exhibits a significant vapor action at room temperature.

  19. Novel, potent and selective inhibitors of protein kinase C show oral anti-inflammatory activity.

    PubMed

    Nixon, J S; Bishop, J; Bradshaw, D; Davis, P D; Hill, C H; Elliott, L H; Kumar, H; Lawton, G; Lewis, E J; Mulqueen, M

    1991-01-01

    Clarification of the precise role of protein kinase C (PKC) in cellular functional responses has been hampered by a lack of potent, selective inhibitors. The structural lead provided by staurosporine, a potent but non-selective protein kinase (PK) inhibitor, was used to derive a series of bis(indolyl)maleimides of which the most potent, Ro 31-8425 (I50: PKC = 8 nM) showed 350-fold selectivity for PKC over cAMP-dependent protein kinase. Ro 31-8425 antagonised cellular processes triggered by phorbol esters (potent, specific PKC activators) and inhibited the allogeneic mixed lymphocyte reaction, suggesting a role for PKC in T-cell activation. Methylation of the primary amine in Ro 31-8425 produced an analogue. Ro 31-8830 which, when administered orally, produced a dose-dependent inhibition of a phorbol ester-induced paw oedema in mice (minimum effective dose = 15 mg/kg). Ro 31-8830 also selectively inhibited the secondary inflammation in a developing adjuvant arthritis model in the rat. The results presented here suggest that these selective inhibitors of PKC may have therapeutic value in the treatment of T-cell-mediated autoimmune diseases.

  20. Novel iodoacetamido benzoheterocyclic derivatives with potent antileukemic activity are inhibitors of STAT5 phosphorylation

    PubMed Central

    Romagnoli, Romeo; Baraldi, Pier Giovanni; Prencipe, Filippo; Lopez-Cara, Carlota; Rondanin, Riccardo; Simoni, Daniele; Hamel, Ernest; Grimaudo, Stefania; Pipitone, Rosaria Maria; Meli, Maria; Tolomeo, Manlio

    2015-01-01

    Signal Transducer and Activator of Transcription 5 (STAT5) protein, a component of the STAT family of signaling proteins, is considered to be an attractive therapeutic target because of its involvement in the progression of acute myeloid leukemia. In an effort to discover potent molecules able to inhibit the phosphorylation-activation of STAT5, twenty-two compounds were synthesized and evaluated on the basis of our knowledge of the activity of 2-(3′,4′,5′-trimethoxybenzoyl)-3-iodoacetamido-6-methoxybenzo[b]furan derivative 1 as a potent STAT5 inhibitor. Most of these molecules, structurally related to compound 1, were characterized by the presence of a common 3′,4′,5′-trimethoxybenzoyl moiety at the 2-position of different benzoheterocycles such as benzo[b]furan, benzo[b]thiophene, indole and N-methylindole. Effects on biological activity of the iodoacetamido group and of different moieties (methyl and methoxy) at the C-3 to C-7 positions were examined. In the series of benzo[b]furan derivatives, moving the iodoacetylamino group from the C-4 to the C-5 or C-6 positions did not significantly affect antiproliferative activity. Compounds 4, 15, 20 and 23 blocked STAT5 signals and induced apoptosis of K562 BCR–ABL positive cells. For compound 23, the trimethoxybenzoyl moiety at the 2-position of the benzo[b]furan core was not essential for potent inhibition of STAT5 activation. PMID:26629859

  1. Discovery of potent and novel S-nitrosoglutathione reductase inhibitors devoid of cytochrome P450 activities.

    PubMed

    Sun, Xicheng; Qiu, Jian; Strong, Sarah A; Green, Louis S; Wasley, Jan W F; Blonder, Joan P; Colagiovanni, Dorothy B; Mutka, Sarah C; Stout, Adam M; Richards, Jane P; Rosenthal, Gary J

    2011-10-01

    The pyrrole based N6022 was recently identified as a potent, selective, reversible, and efficacious S-nitrosoglutathione reductase (GSNOR) inhibitor and is currently undergoing clinical development for the treatment of acute asthma. GSNOR is a member of the alcohol dehydrogenase family (ADH) and regulates the levels of S-nitrosothiols (SNOs) through catabolism of S-nitrosoglutathione (GSNO). Reduced levels of GSNO, as well as other nitrosothiols (SNOs), have been implicated in the pathogenesis of many diseases including those of the respiratory, cardiovascular, and gastrointestinal systems. Preservation of endogenous SNOs through GSNOR inhibition presents a novel therapeutic approach with broad applicability. We describe here the synthesis and structure-activity relationships (SAR) of novel pyrrole based analogues of N6022 focusing on removal of cytochrome P450 inhibition activities. We identified potent and novel GSNOR inhibitors having reduced CYP inhibition activities and demonstrated efficacy in a mouse ovalbumin (OVA) model of asthma.

  2. Vacuolin-1 potently and reversibly inhibits autophagosome-lysosome fusion by activating RAB5A

    PubMed Central

    Lu, Yingying; Dong, Shichen; Hao, Baixia; Li, Chang; Zhu, Kaiyuan; Guo, Wenjing; Wang, Qian; Cheung, King-Ho; Wong, Connie WM; Wu, Wu-Tian; Markus, Huss; Yue, Jianbo

    2014-01-01

    Autophagy is a catabolic lysosomal degradation process essential for cellular homeostasis and cell survival. Dysfunctional autophagy has been associated with a wide range of human diseases, e.g., cancer and neurodegenerative diseases. A large number of small molecules that modulate autophagy have been widely used to dissect this process and some of them, e.g., chloroquine (CQ), might be ultimately applied to treat a variety of autophagy-associated human diseases. Here we found that vacuolin-1 potently and reversibly inhibited the fusion between autophagosomes and lysosomes in mammalian cells, thereby inducing the accumulation of autophagosomes. Interestingly, vacuolin-1 was less toxic but at least 10-fold more potent in inhibiting autophagy compared with CQ. Vacuolin-1 treatment also blocked the fusion between endosomes and lysosomes, resulting in a defect in general endosomal-lysosomal degradation. Treatment of cells with vacuolin-1 alkalinized lysosomal pH and decreased lysosomal Ca2+ content. Besides marginally inhibiting vacuolar ATPase activity, vacuolin-1 treatment markedly activated RAB5A GTPase activity. Expression of a dominant negative mutant of RAB5A or RAB5A knockdown significantly inhibited vacuolin-1-induced autophagosome-lysosome fusion blockage, whereas expression of a constitutive active form of RAB5A suppressed autophagosome-lysosome fusion. These data suggest that vacuolin-1 activates RAB5A to block autophagosome-lysosome fusion. Vacuolin-1 and its analogs present a novel class of drug that can potently and reversibly modulate autophagy. PMID:25483964

  3. Physicochemically and pharmacokinetically stable nonapeptide KISS1 receptor agonists with highly potent testosterone-suppressive activity.

    PubMed

    Asami, Taiji; Nishizawa, Naoki; Matsui, Hisanori; Takatsu, Yoshihiro; Suzuki, Atsuko; Kiba, Atsushi; Terada, Michiko; Nishibori, Kimiko; Nakayama, Masaharu; Ban, Junko; Matsumoto, Shin-ichi; Tarui, Naoki; Ikeda, Yukihiro; Yamaguchi, Masashi; Kusaka, Masami; Ohtaki, Tetsuya; Kitada, Chieko

    2014-07-24

    Modifications of metastin(45-54) produced peptide analogues with higher metabolic stability than metastin(45-54). N-terminally truncated nonapeptide 4 ([D-Tyr46,D-Pya(4)47,azaGly51,Arg(Me)53]metastin(46-54)) is a representative compound with both potent agonistic activity and metabolic stability. Although 4 had more potent testosterone-suppressant activity than metastin, it possessed physicochemical instability at pH 7 and insufficient in vivo activity. Instability at pH 7 was dependent upon Asn48 and Ser49; substitution of Ser49 with Thr49 reduced this instability and maintained KISS1 receptor agonistic activity. Furthermore, [D-Tyr46,D-Trp47,Thr49,azaGly51,Arg(Me)53,Trp54]metastin(46-54) (14) showed 2-fold greater [Ca2+]i-mobilizing activity than metastin(45-54) and an apparent increase in physicochemical stability. N-terminal acetylation of 14 resulted in the most potent analogue, 22 (Ac-[D-Tyr46,D-Trp47,Thr49,azaGly51,Arg(Me)53,Trp54]metastin(46-54)). With continuous administration, 22 possessed 10-50-fold more potent testosterone-suppressive activity in rats than 4. These results suggested that a controlled release of short-length KISS1 receptor agonists can suppress the hypothalamic-pituitary-gonadal axis and reduce testosterone levels. Compound 22 was selected for further preclinical evaluation for hormone-dependent diseases.

  4. Anti-cancer small molecule JP-8g exhibits potent in vivo anti-inflammatory activity

    PubMed Central

    Sun, Yulong; Liu, Jia; Sun, Tao; Zhang, Xiaoyuan; Yao, Jia; Kai, Ming; Jiang, Xianxing; Wang, Rui

    2014-01-01

    Spirooxindoles are a class of compounds with diverse biological activity. Previously, we identified a series of spirooxindole-pyranopyrimidine compounds that exhibited broad-spectrum anti-cancer activity. In this study, we evaluated one of these compounds, JP-8g, on mouse models and found that it showed potent in vivo anti-inflammatory activity. Further investigation suggested that JP-8g may execute its anti-inflammatory activity through nitric oxide synthase signaling pathways. Our results suggest that these spirooxindole-pyranopyrimidine class compounds have potential for not only cancer treatment but also inflammation therapy. PMID:24626153

  5. 3,6-Anhydro-l-galactose, a rare sugar from agar, a new anticariogenic sugar to replace xylitol.

    PubMed

    Yun, Eun Ju; Lee, Ah Reum; Kim, Jung Hyun; Cho, Kyung Mun; Kim, Kyoung Heon

    2017-04-15

    The significance for anticariogenic sugar substitutes is growing due to increasing demands for dietary sugars and rising concerns of dental caries. Xylitol is widely used as an anticariogenic sugar substitute, but the inhibitory effects of xylitol on Streptococcus mutans, the main cause of tooth decay, are exhibited only at high concentrations. Here, the inhibitory effects of 3,6-anhydro-l-galactose (AHG), a rare sugar from red macroalgae, were evaluated on S. mutans, in comparison with those of xylitol. In the presence of 5g/l of AHG, the growth of S. mutans was retarded. At 10g/l of AHG, the growth and acid production by S. mutans were completely inhibited. However, in the presence of xylitol, at a much higher concentration (i.e., 40g/l), the growth of S. mutans still occurred. These results suggest that AHG can be used as a new anticariogenic sugar substitute for preventing dental caries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Extensive screening for edible herbal extracts with potent scavenging activity against superoxide anions.

    PubMed

    Saito, Keita; Kohno, Masahiro; Yoshizaki, Fumihiko; Niwano, Yoshimi

    2008-06-01

    To search for edible herbal extracts with potent antioxidant activity, we conducted a large scale screening based on the superoxide scavenging activity. That is, scavenging activity against superoxide anions were extensively screened from ethanol extracts of approximately 1,000 kinds of herbs by applying an electron spin resonance (ESR)-spin trapping method. Among them we chose four edible herbal extracts with prominently potent ability to reduce the signal intensity of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)-OOH, a spin adduct formed by DMPO and superoxide anion. They are the extracts from Punica granatum (Peel), Syzygium aromaticum (Bud), Mangifera indica (Kernel), and Phyllanthus emblica (Fruit), and are allowed to be used as foodstuffs according to the Japanese legal regulation. The ESR-spin trapping method coupled with steady state kinetic analysis showed that all of the four extracts directly scavenge superoxide anions, and that the superoxide scavenging potential of any of the extracts was comparable to that of L-ascorbic acid. Furthermore, polyphenol determination indicates that the activity is at least in part attributable to polyphenols. These results with such large scale screening might give useful information when choosing a potent antioxidant as a foodstuff.

  7. Synthesis and structure-activity relationships of potent antitumor active quinoline and naphthyridine derivatives.

    PubMed

    Srivastava, Sanjay K; Jha, Amrita; Agarwal, Shiv K; Mukherjee, Rama; Burman, Anand C

    2007-11-01

    The disease of cancer has been ranked second after cardiovascular diseases and plant-derived molecules have played an important role for the treatment of cancer. Nine cytotoxic plant-derived molecules such as vinblastine, vincristine, navelbine, etoposide, teniposide, taxol, taxotere, topotecan and irinotecan have been approved as anticancer drugs. Recently, epothilones are being emerging as future potential anti-tumor agents. However, targeted cancer therapy has now been rapidly expanding and small organic molecules are being exploited for this purpose. Amongst target specific small organic molecules, quinazoline was found as one of the most successful chemical class in cancer chemotherapy as three drugs namely Gefitinib, Erlotinib and Canertinib belong to this series. Now, quinazoline related chemical classes such as quinolines and naphthyridines are being exploited in cancer chemotherapy and a number of molecules such as compounds EKB-569 (52), HKI-272 (78) and SNS-595 (127a) are in different phases of clinical trials. This review presents the synthesis of quinolines and naphthyridines derivatives, screened for anticancer activity since year 2000. The synthesis of most potent derivatives in each prototype has been delineated. A brief structure activity relationship for each prototype has also been discussed. It has been observed that aniline group at C-4, aminoacrylamide substituents at C-6, cyano group at C-3 and alkoxy groups at C-7 in the quinoline ring play an important role for optimal activity. While aminopyrrolidine functionality at C-7, 2'-thiazolyl at N-1 and carboxy group at C-3 in 1,8-naphthyridine ring are essential for eliciting the cytotoxicity. This review would help the medicinal chemist to design and synthesize molecules for targeted cancer chemotherapy.

  8. Monanchocidins B-E: polycyclic guanidine alkaloids with potent antileukemic activities from the sponge Monanchora pulchra.

    PubMed

    Makarieva, Tatyana N; Tabakmaher, Ksenya M; Guzii, Alla G; Denisenko, Vladimir A; Dmitrenok, Pavel S; Shubina, Larisa K; Kuzmich, Alexandra S; Lee, Hyi-Seung; Stonik, Valentin A

    2011-09-23

    New unusual polycyclic guanidine alkaloids monanchocidins B-E (2-5) along with monanchocidin A (1), which we recently described, were isolated from the Far-Eastern marine sponge Monanchora pulchra. Their structures were established using spectroscopic data and chemical transformations. Compounds 1-5 show potent cytotoxic activities against HL-60 human leukemia cells with IC50 values of 540, 200, 110, 830, and 650 nM, respectively.

  9. Discovery and Characterization of 2-Aminooxazolines as Highly Potent, Selective, and Orally Active TAAR1 Agonists

    PubMed Central

    2015-01-01

    2-Aminooxazolines were discovered as a novel structural class of TAAR1 ligands. Starting from a known adrenergic compound 1, structural modifications were made to obtain highly potent and selective TAAR1 ligands such as 12 (RO5166017), 18 (RO5256390), 36 (RO5203648), and 48 (RO5263397). These compounds exhibit drug-like physicochemical properties, have good oral bioavailability, and display in vivo activity in a variety of animal models relevant for psychiatric diseases and addiction. PMID:26985297

  10. Surface-associated proteins from Staphylococcus aureus demonstrate potent bone resorbing activity.

    PubMed

    Nair, S; Song, Y; Meghji, S; Reddi, K; Harris, M; Ross, A; Poole, S; Wilson, M; Henderson, B

    1995-05-01

    Staphylococcus aureus infections are associated with rapid bone destruction in conditions such as osteomyelitis, bacterial arthritis, and infected orthopedic implant failure. How this bacterium induces bone destruction has not been defined. In studies of the role of oral Gram-negative bacteria in periodontal pathology, we have established that cell surface-associated proteins (SAPs) are potent stimulators of bone resorption. The surface-associated components from S. aureus have now been isolated and demonstrated to be extremely potent stimulators of bone resorption in the murine calvarial bone resorption assay. Bone resorption appears to be due to proteins, is not the result of contamination with lipoteichoic acid or muramyl dipeptide, and is potently inhibited by indomethacin and can be completely blocked by high concentrations of interleukin-1 receptor antagonist or TN3-19.12, a neutralizing monoclonal antibody to murine TNF. The SAP fraction can stimulate fibroblasts or monocytes to release osteolytic cytokines, but only at high concentrations. Fractionation of the SAPs by high performance liquid chromatography demonstrated that a number of fractions were osteolytically active. The most active contained a heterodimeric protein of molecular weight 32-36 kD. The presence of this osteolytically active surface-associated fraction may account for the bone resorption associated with local infection with S. aureus.

  11. Potent inhibitors of tyrosinase activity and melanin biosynthesis from Rheum officinale.

    PubMed

    Iida, K; Hase, K; Shimomura, K; Sudo, S; Kadota, S; Namba, T

    1995-10-01

    Thirty-three crude drug extracts were screened for their tyrosinase inhibitory activity. Among them, the acetone extract of the rhizomes of Rheum officinale Baillon showed the strongest inhibitory activity. Tyrosinase inhibitory activity-guided fractionation and chemical analysis led to the isolation of two potent compounds, 3,4',5-trihydroxystilbene-4'-O-beta-D-(2"-O-galloyl)glucopyr anoside (1) and 3,4',5-trihydroxystilbene-4'-O-beta-D-(6"-O-galloyl)glucopyr anoside (2). These compounds showed a competitive inhibition against tyrosinase and also inhibited the melanin biosynthesis.

  12. 8-hydroxydihydrochelerythrine and 8-hydroxydihydrosanguinarine with a potent acetylcholinesterase inhibitory activity from Chelidonium majus L.

    PubMed

    Cho, Kyung-Mi; Yoo, Ick-Dong; Kim, Won-Gon

    2006-11-01

    Ethanol extract of the aerial portion of Chelidonium majus L. inhibited acetylcholinesterase (AChE) activity without a significant inhibition of butyrylcholinesterase (BuChE). Using mass spectrometry and NMR studies, three active constituents were isolated and identified: 8-hydroxydihydrochelerythrine (1), 8-hydroxydihydrosanguinarine (2), and berberine (3). Compounds 1-3 showed potent inhibitory activity against AChE, with IC50 (microM) values of 0.61-1.85. Compound 1 exhibited competitive and selective inhibition for AChE.

  13. A Potent, Selective and Cell-Active Allosteric Inhibitor of Protein Arginine Methyltransferase 3 (PRMT3)**

    PubMed Central

    Kaniskan, H. Ümit; Szewczyk, Magdalena M.; Yu, Zhengtian; Eram, Mohammad S.; Yang, Xiaobao; Schmidt, Keith; Luo, Xiao; Dai, Miao; He, Feng; Zang, Irene; Lin, Ying; Kennedy, Steven; Li, Fengling; Dobrovetsky, Elena; Dong, Aiping; Smil, David; Min, Sun-Joon; Landon, Melissa; Lin-Jones, Jennifer; Huang, Xi-Ping; Roth, Bryan L.; Schapira, Matthieu; Atadja, Peter; Barsyte-Lovejoy, Dalia; Arrowsmith, Cheryl H.; Brown, Peter J.; Zhao, Kehao; Jin, Jian; Vedadi, Masoud

    2015-01-01

    PRMT3 catalyzes the asymmetric dimethylation of arginine residues of various proteins. It is essential for maturation of ribosomes, may have a role in lipogenesis, and is implicated in several diseases. A potent, selective, and cell- active PRMT3 inhibitor would be a valuable tool for further investigating PRMT3 biology. Here we report the discovery of the first PRMT3 chemical probe, SGC707, by structure-based optimization of the allosteric PRMT3 inhibitors we reported previously, and thorough characterization of this probe in biochemical, biophysical, and cellular assays. SGC707 is a potent PRMT3 inhibitor (IC50 = 31 ± 2 nm, KD = 53 ± 2 nm) with outstanding selectivity (selective against 31 other methyltransferases and more than 250 non-epigenetic targets). The mechanism of action studies and crystal structure of the PRMT3-SGC707 complex confirm the allosteric inhibition mode. Importantly, SGC707 engages PRMT3 and potently inhibits its methyltransferase activity in cells. It is also bioavailable and suitable for animal studies. This well- characterized chemical probe is an excellent tool to further study the role of PRMT3 in health and disease. PMID:25728001

  14. Adenosine Receptor Prodrugs: Synthesis and Biological Activity of Derivatives of Potent, A1-Selective Agonists

    PubMed Central

    Maillrad, Michel C.; Nikodijević, Olga; LaNoue, Kathryn F.; Berkich, Deborah; Xiao-duo, JI; Bartus, Raymond

    2012-01-01

    5′-Ester derivatives of the potent adenosine agonists N6-[4-[[[[4-[[[(2-acetylaminoethyl)amino] carbonyl] methyl] anilino] carbonyl] methyl] phenyl] adenosine (N-AcADAC; 1) and N6-cyclopentyladenosine (CPA; 2) were prepared as prodrugs. Both alkyl esters or carbonates (designed to enter the brain by virtue of increased lipophilicity) and 1,4-dihydro-1-methyl-3- [(pyridinylcarbonyl)oxy] esters designed to concentrate in the brain by virtue of a redox delivery system were synthesized. In the 5′-blocked form, the adenosine agonists displayed highly diminished affinity for rat brain A1-adenosine receptors in binding assays. The dihydropyridine prodrug 29 was active in an assay of locomotor depression in mice, in which adenosine agonists are highly depressant. The behavior depression was not reversible by peripheral administration of a non-central nervous system active adenosine antagonist. In an assay of the peripheral action of adenosine (i.e., the inhibition of lipolysis in rats), the parent compounds were highly potent and the dihydropyridine prodrug was much less potent. PMID:8138909

  15. Synthesis, evaluation, and metabolism of novel [6]-shogaol derivatives as potent Nrf2 activators.

    PubMed

    Zhu, Yingdong; Wang, Pei; Zhao, Yantao; Yang, Chun; Clark, Anderson; Leung, TinChung; Chen, Xiaoxin; Sang, Shengmin

    2016-06-01

    Oxidative stress is a central component of many chronic diseases. The Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2 p45-related factor 2 (Nrf2) system is a major regulatory pathway of cytoprotective genes against oxidative and electrophilic stress. Activation of the Nrf2 pathway plays crucial roles in the chemopreventive effects of various inducers. In this study, we developed a novel class of potent Nrf2 activators derived from ginger compound, [6]-shogaol (6S), using the Tg[glutathione S-transferase pi 1 (gstp1):green fluorescent protein (GFP)] transgenic zebrafish model. Investigation of structure-activity relationships of 6S derivatives indicates that the combination of an α,β-unsaturated carbonyl entity and a catechol moiety in one compound enhances the Tg(gstp1:GFP) fluorescence signal in zebrafish embryos. Chemical reaction and in vivo metabolism studies of the four most potent 6S derivatives showed that both α,β-unsaturated carbonyl entity and catechol moiety act as major active groups for conjugation with the sulfhydryl groups of the cysteine residues. In addition, we further demonstrated that 6S derivatives increased the expression of Nrf2 downstream target, heme oxygenase-1, in both a dose- and time-dependent manner. These results suggest that α,β-unsaturated carbonyl entity and catechol moiety of 6S derivatives may react with the cysteine residues of Keap1, disrupting the Keap1-Nrf2 complex, thereby liberating and activating Nrf2. Our findings of natural product-derived Nrf2 activators lead to design options of potent Nrf2 activators for further optimization.

  16. Polycyclic N-benzamido imides with potent activity against vaccinia virus.

    PubMed

    Torres, Eva; Duque, María D; Camps, Pelayo; Naesens, Lieve; Calvet, Teresa; Font-Bardia, Mercè; Vázquez, Santiago

    2010-12-03

    The synthesis and antiviral activity of a series of novel polycyclic analogues of the orthopoxvirus egress inhibitor tecovirimat (ST-246) is presented. Several of these compounds display sub-micromolar activity against vaccinia virus, and were more potent than cidofovir (CDV). The more active compounds were about 10-fold more active than CDV, with minimum cytotoxic concentrations above 100 μM. Chemical manipulations of the two carbon-carbon double bonds present in the compounds were carried out to further explore the structure-activity relationships of these new polycyclic imides. Hydrogenation of the two carbon-carbon double bonds decreases antiviral activity, whereas either cyclopropanation or epoxidation of the double bonds fully eliminates the antiviral activity.

  17. Selective and potent in vitro antitrypanosomal activities of ten microbial metabolites.

    PubMed

    Otoguro, Kazuhiko; Ishiyama, Aki; Namatame, Miyuki; Nishihara, Aki; Furusawa, Toshiaki; Masuma, Rokuro; Shiomi, Kazuro; Takahashi, Yoko; Yamada, Haruki; Omura, Satoshi

    2008-06-01

    More than 400 compounds isolated from soil microorganisms, and catalogued in the antibiotic library of the Kitasato Institute for Life Sciences, were screened against African trypanosomes. Ten compounds were found to have selective and potent antitrypanosomal activity in vitro: aureothin, cellocidin, destomycin A, echinomycin, hedamycin, irumamycin, LL-Z 1272beta, O-methylnanaomycin A, venturicidin A and virustomycin A. Results of the in vitro assays using the GUTat 3.1 strain of Trypanosomal brucei brucei and the STIB900 strain of T. b. rhodesiense are presented. Cytotoxicity was determined using a human MRC-5 cell line. This is the first report of antitrypanosomal activities of the 10 microbial metabolites listed above.

  18. Cardenolides from Calotropis gigantea as potent inhibitors of hypoxia-inducible factor-1 transcriptional activity.

    PubMed

    Parhira, Supawadee; Zhu, Guo-Yuan; Chen, Ming; Bai, Li-Ping; Jiang, Zhi-Hong

    2016-12-24

    Calotropis gigantea (L.) Dryand (Apocynaceae) is a medicinal plant native to southern China, India and Southeast Asia. It has been traditionally used for the treatment of several diseases including cancers in these countries. This study aimed to isolate bioactive cardenolides from C. gigantea, to screen their hypoxia-inducible factor (HIF-) 1 inhibitory activity, and to analyze the structure-activity relationship (SAR). Isolation and purification of cardenolides from the latex and the fruits of C. gigantea were performed by using a series of separation techniques. Their structures were fully characterized by elucidating their NMR and HRMS data. The HIF-1 inhibitory activities of cardenolides were evaluated by using a T47D cell-based dual-luciferase reporter assay. The potent cardenolides were selected to further evaluate their dose-response manner. Cytotoxic effects of selected cardenolides were also examined against breast cancer cell line (MCF-7) and normal mammary epithelial cell line (MCF-10A) by MTT assay. Among twenty isolated cardenolides, compounds 1, 3, 4, 6-8, 14 and 17 exhibited stronger HIF-1 inhibitory activities than that of digoxin, a well-known HIF-1 inhibitor (P<0.001). These eight cardenolides inhibited HIF-1 transcriptional activity in a dose-dependent manner with IC50 values in nanomolar potency (21.8-64.9nM). An analysis of SAR revealed the great contributions of a β-configuration of the substituents at positions of C-2' and C-3', an aldehydic moiety on C-19, and the dioxane moiety between the aglycone and sugar parts of cardenolides to the HIF-1 inhibitory activity. In contrast, a hydroxyl group at any positions of C-15, C-16 and C-4' of cardenolides showed negative effects on suppressing HIF-1 transcriptional activity. In addition, these eight cardenolides also exhibited potent cytotoxic effects against human breast cancer cell MCF-7 (IC50 values ranged from 30.5 to 68.8nM), but less toxic effects to human normal mammary epithelial cell MCF

  19. Potent free radical scavenging activity of propol isolated from Brazilian propolis.

    PubMed

    Basnet, P; Matsuno, T; Neidlein, R

    1997-01-01

    We evaluated free radical scavenging activity of the water, methanol and chloroform extracts of propolis in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and xanthine-xanthine oxidase (XOD) generated superoxide anion assay systems. The free radical scavenging activity guided fractionation and chemical analysis led to the isolation of a new compound, propol (3-[4-hydroxy-3-(3-oxo-but-1-enyl)-phenyl]-acrylic acid) from the water extract, which was more potent than most common antioxidants such as vitamin C and vitamin E (alpha-tocopherol) in these assay systems.

  20. UV-inactivated HSV-1 potently activates NK cell killing of leukemic cells.

    PubMed

    Samudio, Ismael; Rezvani, Katayoun; Shaim, Hila; Hofs, Elyse; Ngom, Mor; Bu, Luke; Liu, Guoyu; Lee, Jason T C; Imren, Suzan; Lam, Vivian; Poon, Grace F T; Ghaedi, Maryam; Takei, Fumio; Humphries, Keith; Jia, William; Krystal, Gerald

    2016-05-26

    Herein we demonstrate that oncolytic herpes simplex virus-1 (HSV-1) potently activates human peripheral blood mononuclear cells (PBMCs) to lyse leukemic cell lines and primary acute myeloid leukemia samples, but not healthy allogeneic lymphocytes. Intriguingly, we found that UV light-inactivated HSV-1 (UV-HSV-1) is equally effective in promoting PBMC cytolysis of leukemic cells and is 1000- to 10 000-fold more potent at stimulating innate antileukemic responses than UV-inactivated cytomegalovirus, vesicular stomatitis virus, reovirus, or adenovirus. Mechanistically, UV-HSV-1 stimulates PBMC cytolysis of leukemic cells, partly via Toll-like receptor-2/protein kinase C/nuclear factor-κB signaling, and potently stimulates expression of CD69, degranulation, migration, and cytokine production in natural killer (NK) cells, suggesting that surface components of UV-HSV-1 directly activate NK cells. Importantly, UV-HSV-1 synergizes with interleukin-15 (IL-15) and IL-2 in inducing activation and cytolytic activity of NK cells. Additionally, UV-HSV-1 stimulates glycolysis and fatty acid oxidation-dependent oxygen consumption in NK cells, but only glycolysis is required for their enhanced antileukemic activity. Last, we demonstrate that T cell-depleted human PBMCs exposed to UV-HSV-1 provide a survival benefit in a murine xenograft model of human acute myeloid leukemia (AML). Taken together, our results support the preclinical development of UV-HSV-1 as an adjuvant, alone or in combination with IL-15, for allogeneic donor mononuclear cell infusions to treat AML.

  1. UV-inactivated HSV-1 potently activates NK cell killing of leukemic cells

    PubMed Central

    Samudio, Ismael; Rezvani, Katayoun; Shaim, Hila; Hofs, Elyse; Ngom, Mor; Bu, Luke; Liu, Guoyu; Lee, Jason T. C.; Imren, Suzan; Lam, Vivian; Poon, Grace F. T.; Ghaedi, Maryam; Takei, Fumio; Humphries, Keith; Jia, William

    2016-01-01

    Herein we demonstrate that oncolytic herpes simplex virus-1 (HSV-1) potently activates human peripheral blood mononuclear cells (PBMCs) to lyse leukemic cell lines and primary acute myeloid leukemia samples, but not healthy allogeneic lymphocytes. Intriguingly, we found that UV light–inactivated HSV-1 (UV-HSV-1) is equally effective in promoting PBMC cytolysis of leukemic cells and is 1000- to 10 000-fold more potent at stimulating innate antileukemic responses than UV-inactivated cytomegalovirus, vesicular stomatitis virus, reovirus, or adenovirus. Mechanistically, UV-HSV-1 stimulates PBMC cytolysis of leukemic cells, partly via Toll-like receptor-2/protein kinase C/nuclear factor-κB signaling, and potently stimulates expression of CD69, degranulation, migration, and cytokine production in natural killer (NK) cells, suggesting that surface components of UV-HSV-1 directly activate NK cells. Importantly, UV-HSV-1 synergizes with interleukin-15 (IL-15) and IL-2 in inducing activation and cytolytic activity of NK cells. Additionally, UV-HSV-1 stimulates glycolysis and fatty acid oxidation–dependent oxygen consumption in NK cells, but only glycolysis is required for their enhanced antileukemic activity. Last, we demonstrate that T cell–depleted human PBMCs exposed to UV-HSV-1 provide a survival benefit in a murine xenograft model of human acute myeloid leukemia (AML). Taken together, our results support the preclinical development of UV-HSV-1 as an adjuvant, alone or in combination with IL-15, for allogeneic donor mononuclear cell infusions to treat AML. PMID:26941401

  2. A Class of 5-Nitro-2-furancarboxylamides with Potent Trypanocidal Activity against Trypanosoma brucei in Vitro

    PubMed Central

    2013-01-01

    Recently, the World Health Organization approved the nifurtimox–eflornithine combination therapy for the treatment of human African trypanosomiasis, renewing interest in nitroheterocycle therapies for this and associated diseases. In this study, we have synthesized a series of novel 5-nitro-2-furancarboxylamides that show potent trypanocidal activity, ∼1000-fold more potent than nifurtimox against in vitro Trypanosoma brucei with very low cytotoxicity against human HeLa cells. More importantly, the most potent analogue showed very limited cross-resistance to nifurtimox-resistant cells and vice versa. This implies that our novel, relatively easy to synthesize and therefore cheap, 5-nitro-2-furancarboxylamides are targeting a different, but still essential, biochemical process to those targeted by nifurtimox or its metabolites in the parasites. The significant increase in potency (smaller dose probably required) has the potential for greatly reducing unwanted side effects and also reducing the likelihood of drug resistance. Collectively, these findings have important implications for the future therapeutic treatment of African sleeping sickness. PMID:23281892

  3. Learning from Host-Defense Peptides: Cationic, Amphipathic Peptoids with Potent Anticancer Activity

    PubMed Central

    Willingham, Stephen B.; Czyzewski, Ann M.; Gonzalgo, Mark L.; Weissman, Irving L.; Barron, Annelise E.

    2014-01-01

    Cationic, amphipathic host defense peptides represent a promising group of agents to be developed for anticancer applications. Poly-N-substituted glycines, or peptoids, are a class of biostable, peptidomimetic scaffold that can display a great diversity of side chains in highly tunable sequences via facile solid-phase synthesis. Herein, we present a library of anti-proliferative peptoids that mimics the cationic, amphipathic structural feature of the host defense peptides and explore the relationships between the structure, anticancer activity and selectivity of these peptoids. Several peptoids are found to be potent against a broad range of cancer cell lines at low-micromolar concentrations including cancer cells with multidrug resistance (MDR), causing cytotoxicity in a concentration-dependent manner. They can penetrate into cells, but their cytotoxicity primarily involves plasma membrane perturbations. Furthermore, peptoid 1, the most potent peptoid synthesized, significantly inhibited tumor growth in a human breast cancer xenotransplantation model without any noticeable acute adverse effects in mice. Taken together, our work provided important structural information for designing host defense peptides or their mimics for anticancer applications. Several cationic, amphipathic peptoids are very attractive for further development due to their high solubility, stability against protease degradation, their broad, potent cytotoxicity against cancer cells and their ability to overcome multidrug resistance. PMID:24587350

  4. Learning from host-defense peptides: cationic, amphipathic peptoids with potent anticancer activity.

    PubMed

    Huang, Wei; Seo, Jiwon; Willingham, Stephen B; Czyzewski, Ann M; Gonzalgo, Mark L; Weissman, Irving L; Barron, Annelise E

    2014-01-01

    Cationic, amphipathic host defense peptides represent a promising group of agents to be developed for anticancer applications. Poly-N-substituted glycines, or peptoids, are a class of biostable, peptidomimetic scaffold that can display a great diversity of side chains in highly tunable sequences via facile solid-phase synthesis. Herein, we present a library of anti-proliferative peptoids that mimics the cationic, amphipathic structural feature of the host defense peptides and explore the relationships between the structure, anticancer activity and selectivity of these peptoids. Several peptoids are found to be potent against a broad range of cancer cell lines at low-micromolar concentrations including cancer cells with multidrug resistance (MDR), causing cytotoxicity in a concentration-dependent manner. They can penetrate into cells, but their cytotoxicity primarily involves plasma membrane perturbations. Furthermore, peptoid 1, the most potent peptoid synthesized, significantly inhibited tumor growth in a human breast cancer xenotransplantation model without any noticeable acute adverse effects in mice. Taken together, our work provided important structural information for designing host defense peptides or their mimics for anticancer applications. Several cationic, amphipathic peptoids are very attractive for further development due to their high solubility, stability against protease degradation, their broad, potent cytotoxicity against cancer cells and their ability to overcome multidrug resistance.

  5. Tremorgenic indole alkaloids potently inhibit smooth muscle high-conductance calcium-activated potassium channels.

    PubMed

    Knaus, H G; McManus, O B; Lee, S H; Schmalhofer, W A; Garcia-Calvo, M; Helms, L M; Sanchez, M; Giangiacomo, K; Reuben, J P; Smith, A B

    1994-05-17

    Tremorgenic indole alkaloids produce neurological disorders (e.g., staggers syndromes) in ruminants. The mode of action of these fungal mycotoxins is not understood but may be related to their known effects on neurotransmitter release. To determine whether these effects could be due to inhibition of K+ channels, the interaction of various indole diterpenes with high-conductance Ca(2+)-activated K+ (maxi-K) channels was examined. Paspalitrem A, paspalitrem C, aflatrem, penitrem A, and paspalinine inhibit binding of [125I]charybdotoxin (ChTX) to maxi-K channels in bovine aortic smooth muscle sarcolemmal membranes. In contrast, three structurally related compounds, paxilline, verruculogen, and paspalicine, enhanced toxin binding. As predicted from the binding studies, covalent incorporation of [125I]ChTX into the 31-kDa subunit of the maxi-K channel was blocked by compounds that inhibit [125I]ChTX binding and enhanced by compounds that stimulate [125I]ChTX binding. Modulation of [125I]ChTX binding was due to allosteric mechanisms. Despite their different effects on binding of [125I]ChTX to maxi-K channels, all compounds potently inhibited maxi-K channels in electrophysiological experiments. Other types of voltage-dependent or Ca(2+)-activated K+ channels examined were not affected. Chemical modifications of paxilline indicate a defined structure-activity relationship for channel inhibition. Paspalicine, a deshydroxy analog of paspalinine lacking tremorgenic activity, also potently blocked maxi-K channels. Taken together, these data suggest that indole diterpenes are the most potent nonpeptidyl inhibitors of maxi-K channels identified to date. Some of their pharmacological properties could be explained by inhibition of maxi-K channels, although tremorgenicity may be unrelated to channel block.

  6. Identification of new potent phthalazine derivatives with VEGFR-2 and EGFR kinase inhibitory activity.

    PubMed

    Amin, Kamilia M; Barsoum, Flora F; Awadallah, Fadi M; Mohamed, Nehal E

    2016-11-10

    Efforts to develop new antitumor agents are now directed towards multitarget therapies that are believed to have high potency and low tendency to resistance compared to conventional drugs. Herein, we highlighted the synthesis and antitumor activity of five series of phthalazine-based compounds featuring a variety of bioactive chemical fragments at position 1 of the phthalazine nucleus. The antitumor activity of the target compounds was performed against fourteen cancer cell lines where all compounds were active in the nanomolar level. In addition, the mechanism of action of the target compounds was investigated through an enzymatic inhibitory assay against VEGFR-2 and EGFR kinases, revealing potent and preferential activity toward VEGFR-2. Binding mode of the most active compounds was studied using docking experiment.

  7. A novel peptide with potent and broad-spectrum antiviral activities against multiple respiratory viruses

    PubMed Central

    Zhao, Hanjun; Zhou, Jie; Zhang, Ke; Chu, Hin; Liu, Dabin; Poon, Vincent Kwok-Man; Chan, Chris Chung-Sing; Leung, Ho-Chuen; Fai, Ng; Lin, Yong-Ping; Zhang, Anna Jin-Xia; Jin, Dong-Yan; Yuen, Kwok-Yung; Zheng, Bo-Jian

    2016-01-01

    A safe, potent and broad-spectrum antiviral is urgently needed to combat emerging respiratory viruses. In light of the broad antiviral activity of β-defensins, we tested the antiviral activity of 11 peptides derived from mouse β-defensin-4 and found that a short peptide, P9, exhibited potent and broad-spectrum antiviral effects against multiple respiratory viruses in vitro and in vivo, including influenza A virus H1N1, H3N2, H5N1, H7N7, H7N9, SARS-CoV and MERS-CoV. The antiviral activity of P9 was attributed to its high-affinity binding to viral glycoproteins, as well as the abundance of basic amino acids in its composition. After binding viral particles through viral surface glycoproteins, P9 entered into cells together with the viruses via endocytosis and prevented endosomal acidification, which blocked membrane fusion and subsequent viral RNA release. This study has paved the avenue for developing new prophylactic and therapeutic agents with broad-spectrum antiviral activities. PMID:26911565

  8. Discovery of a Selective Inhibitor of Oncogenic B-Raf Kinase With Potent Antimelanoma Activity

    SciTech Connect

    Tsai, J.; Lee, J.T.; Wang, W.; Zhang, J.; Cho, H.; Mamo, S.; Bremer, R.; Gillette, S.; Kong, J.; Haass, N.K.; Sproesser, K.; Li, L.; Smalley, K.S.M.; Fong, D.; Zhu, Y.-L.; Marimuthu, A.; Nguyen, H.; Lam, B.; Liu, J.; Cheung, I.; Rice, J.

    2009-05-26

    BRAF{sup V600E} is the most frequent oncogenic protein kinase mutation known. Furthermore, inhibitors targeting 'active' protein kinases have demonstrated significant utility in the therapeutic repertoire against cancer. Therefore, we pursued the development of specific kinase inhibitors targeting B-Raf, and the V600E allele in particular. By using a structure-guided discovery approach, a potent and selective inhibitor of active B-Raf has been discovered. PLX4720, a 7-azaindole derivative that inhibits B-Raf{sup V600E} with an IC{sub 50} of 13 nM, defines a class of kinase inhibitor with marked selectivity in both biochemical and cellular assays. PLX4720 preferentially inhibits the active B-Raf{sup V600E} kinase compared with a broad spectrum of other kinases, and potent cytotoxic effects are also exclusive to cells bearing the V600E allele. Consistent with the high degree of selectivity, ERK phosphorylation is potently inhibited by PLX4720 in B-Raf{sup V600E}-bearing tumor cell lines but not in cells lacking oncogenic B-Raf. In melanoma models, PLX4720 induces cell cycle arrest and apoptosis exclusively in B-Raf{sup V600E}-positive cells. In B-Raf{sup V600E}-dependent tumor xenograft models, orally dosed PLX4720 causes significant tumor growth delays, including tumor regressions, without evidence of toxicity. The work described here represents the entire discovery process, from initial identification through structural and biological studies in animal models to a promising therapeutic for testing in cancer patients bearing B-Raf{sup V600E}-driven tumors.

  9. An unusual "senseless" 2',5'-oligoribonucleotide with potent anti-HIV activity.

    PubMed

    Aboul-Fadl, Tarek; Agrawal, Vijai K; Buckheit, Robert W; Broom, Arthur D

    2004-01-01

    A new 32-mer 2',5'-oligoribonucleotide of 1-methyl-6-thioinosinic acid (10) has been synthesized. The design of this unique oligoribonucleotide is based on the reported HIV inhibitory activities of both 2',5'-oligonucleotides and the 3',5'-oligoribonucleotides containing the 1-methyl-6-mercaptopurine base. Tm and CD studies of 10 revealed that it has no organized secondary structure, presumably due to the rigidity of the molecule. The synthesized oligomer, 10, showed a potent inhibitory effect on HIV-1RF and significantly inhibited HIV-1 reverse transcriptase.

  10. Discovery and structure-activity relationships of urea derivatives as potent and novel CCR3 antagonists.

    PubMed

    Nitta, Aiko; Iura, Yosuke; Tomioka, Hiroki; Sato, Ippei; Morihira, Koichiro; Kubota, Hirokazu; Morokata, Tatsuaki; Takeuchi, Makoto; Ohta, Mitsuaki; Tsukamoto, Shin-ichi; Imaoka, Takayuki; Takahashi, Toshiya

    2012-08-01

    The synthesis and structure-activity relationships of ureas as CCR3 antagonists are described. Optimization starting with lead compound 2 (IC(50)=190 nM) derived from initial screening hit compound 1 (IC(50)=600 nM) led to the identification of (S)-N-((1R,3S,5S)-8-((6-fluoronaphthalen-2-yl)methyl)-8-azabicyclo[3.2.1]octan-3-yl)-N-(2-nitrophenyl)pyrrolidine-1,2-dicarboxamide 27 (IC(50)=4.9 nM) as a potent CCR3 antagonist.

  11. Bipiperidinyl carboxylic acid amides as potent, selective, and functionally active CCR4 antagonists.

    PubMed

    Kuhn, Cyrille F; Bazin, Marc; Philippe, Laurence; Zhang, Jiansu; Tylaska, Laurie; Miret, Juan; Bauer, Paul H

    2007-09-01

    A cell-based assay for the chemokine G-protein-coupled receptor CCR4 was developed, and used to screen a small-molecule compound collection in a multiplex format. A series of bipiperidinyl carboxylic acid amides amenable to parallel chemistry were derived that were potent and selective antagonists of CCR4. One prototype compound was shown to be active in a functional model of chemotaxis, making it a useful chemical tool to explore the role of CCR4 in asthma, allergy, diabetes, and cancer.

  12. Triazolopyridine ethers as potent, orally active mGlu2 positive allosteric modulators for treating schizophrenia.

    PubMed

    Higgins, Mendi A; Marcin, Lawrence R; Christopher Zusi, F; Gentles, Robert; Ding, Min; Pearce, Bradley C; Easton, Amy; Kostich, Walter A; Seager, Matthew A; Bourin, Clotilde; Bristow, Linda J; Johnson, Kim A; Miller, Regina; Hogan, John; Whiterock, Valerie; Gulianello, Michael; Ferrante, Meredith; Huang, Yanling; Hendricson, Adam; Alt, Andrew; Macor, John E; Bronson, Joanne J

    2017-01-15

    Triazolopyridine ethers with mGlu2 positive allosteric modulator (PAM) activity are disclosed. The synthesis, in vitro activity, and metabolic stability data for a series of analogs is provided. The effort resulted in the discovery of a potent, selective, and brain penetrant lead molecule BMT-133218 ((+)-7m). After oral administration at 10mg/kg, BMT-133218 demonstrated full reversal of PCP-stimulated locomotor activity and prevented MK-801-induced working memory deficits in separate mouse models. Also, reversal of impairments in executive function were observed in rat set-shifting studies at 3 and 10mg/kg (p.o.). Extensive plasma protein binding as the result of high lipophilicity likely limited activity at lower doses. Optimized triazolopyridine ethers offer utility as mGlu2 PAMs for the treatment of schizophrenia and merit further preclinical investigation.

  13. Aromatic lipoxin A4 and lipoxin B4 analogues display potent biological activities.

    PubMed

    O'Sullivan, Timothy P; Vallin, Karl S A; Shah, Syed Tasadaque Ali; Fakhry, Jérôme; Maderna, Paola; Scannell, Michael; Sampaio, Andre L F; Perretti, Mauro; Godson, Catherine; Guiry, Patrick J

    2007-11-29

    Lipoxins are a group of biologically active eicosanoids typically formed by transcellular lipoxygenase activity. Lipoxin A4 (LXA4) and Lipoxin B4 (LXB4) biosynthesis has been detected in a variety of inflammatory conditions. The native lipoxins LXA4 and LXB4 demonstrate potent antiinflammatory and proresolution bioactions. However, their therapeutic potential is compromised by rapid metabolic inactivation by PG dehydrogenase-mediated oxidation and reduction. Here we report on the stereoselective synthesis of aromatic LXA4 and LXB4 analogues by employing Sharpless epoxidation, Pd-mediated Heck coupling, and diastereoselective reduction as the key transformations. Subsequent biological testing has shown that these analogues display potent biological activities. Phagocytic clearance of apoptotic leukocytes plays a critical role in the resolution of inflammation. Both LXA4 analogues (1R)-3a and (1S)-3a were found to stimulate a significant increase in phagocytosis of apoptotic polymorphonuclear leukocytes (PMN) by macrophages, with comparable efficacy to the effect of native LXA4, albeit greater potency, while the LXB4 analogue also stimulated phagocytosis with a maximum effect observed at 10-11 M. LX-stimulated phagocytosis was associated with rearrangement of the actin cytoskeleton consistent with that reported for native lipoxins. Using zymosan-induced peritonitis as a murine model of acute inflammation (1R)-3a significantly reduced PMN accumulation.

  14. Synthesis and SAR studies of benzyl ether derivatives as potent orally active S1P₁ agonists.

    PubMed

    Tsuji, Takashi; Suzuki, Keisuke; Nakamura, Tsuyoshi; Goto, Taiji; Sekiguchi, Yukiko; Ikeda, Takuya; Fukuda, Takeshi; Takemoto, Toshiyasu; Mizuno, Yumiko; Kimura, Takako; Kawase, Yumi; Nara, Futoshi; Kagari, Takashi; Shimozato, Takaichi; Yahara, Chizuko; Inaba, Shinichi; Honda, Tomohiro; Izumi, Takashi; Tamura, Masakazu; Nishi, Takahide

    2014-08-01

    We report herein the synthesis and structure-activity relationships (SAR) of a series of benzyl ether compounds as an S1P₁ receptor modulator. From our SAR studies, the installation of substituents onto the central benzene ring of 2a was revealed to potently influence the S1P₁ and S1P₃ agonistic activities, in particular, an ethyl group on the 2-position afforded satisfactory S1P₁/S1P₃ selectivity. These changes of the S1P₁ and S1P₃ agonistic activities caused by the alteration of substituents on the 2-position were reasonably explained by a docking study using an S1P₁ X-ray crystal structure and S1P₃ homology modeling. We found that compounds 2b and 2e had a potent in vivo immunosuppressive efficacy along with acceptable S1P₁/S1P₃ selectivity, and confirmed that these compounds had less in vivo bradycardia risk through the evaluation of heart rate change after oral administration of the compounds (30 mg/kg, p.o.) in rats.

  15. Novel Radiolytic Rotenone Derivative, Rotenoisin B with Potent Anti-Carcinogenic Activity in Hepatic Cancer Cells.

    PubMed

    Badaboina, Srilatha; Bai, Hyoung-Woo; Na, Yun Hee; Park, Chul-Hong; Kim, Tae Hoon; Lee, Tae-Hoon; Chung, Byung Yeoup

    2015-07-24

    Rotenone, isolated from roots of derris plant, has been shown to possess various biological activities, which lead to attempting to develop a potent drug against several diseases. However, recent studies have demonstrated that rotenone has the potential to induce several adverse effects such as a neurodegenerative disease. Radiolytic transformation of the rotenone with gamma-irradiation created a new product, named rotenoisin B. The present work was designed to investigate the anticancer activity of rotenoisin B with low toxicity and its molecular mechanism in hepatic cancer cells compared to a parent compound, rotenone. Our results showed rotenoisin B inhibited hepatic cancer cells' proliferation in a dose dependent manner and increased in apoptotic cells. Interestingly, rotenoisin B showed low toxic effects on normal cells compared to rotenone. Mitochondrial transmembrane potential has been decreased, which leads to cytochrome c release. Down regulation of anti-apoptotic Bcl-2 levels as well as the up regulation of proapoptotic Bax levels were observed. The cleaved PARP (poly ADP-ribose polymerase) level increased as well. Moreover, phosphorylation of extracellular signal regulated kinase (ERK) and p38 slightly up regulated and intracellular reactive oxygen species (ROS) increased as well as cell cycle arrest predominantly at the G2/M phase observed. These results suggest that rotenoisin B might be a potent anticancer candidate similar to rotenone in hepatic cancer cells with low toxicity to normal cells even at high concentrations compared to rotenone.

  16. Novel Radiolytic Rotenone Derivative, Rotenoisin B with Potent Anti-Carcinogenic Activity in Hepatic Cancer Cells

    PubMed Central

    Badaboina, Srilatha; Bai, Hyoung-Woo; Na, Yun Hee; Park, Chul-Hong; Kim, Tae Hoon; Lee, Tae-Hoon; Chung, Byung Yeoup

    2015-01-01

    Rotenone, isolated from roots of derris plant, has been shown to possess various biological activities, which lead to attempting to develop a potent drug against several diseases. However, recent studies have demonstrated that rotenone has the potential to induce several adverse effects such as a neurodegenerative disease. Radiolytic transformation of the rotenone with gamma-irradiation created a new product, named rotenoisin B. The present work was designed to investigate the anticancer activity of rotenoisin B with low toxicity and its molecular mechanism in hepatic cancer cells compared to a parent compound, rotenone. Our results showed rotenoisin B inhibited hepatic cancer cells’ proliferation in a dose dependent manner and increased in apoptotic cells. Interestingly, rotenoisin B showed low toxic effects on normal cells compared to rotenone. Mitochondrial transmembrane potential has been decreased, which leads to cytochrome c release. Down regulation of anti-apoptotic Bcl-2 levels as well as the up regulation of proapoptotic Bax levels were observed. The cleaved PARP (poly ADP-ribose polymerase) level increased as well. Moreover, phosphorylation of extracellular signal regulated kinase (ERK) and p38 slightly up regulated and intracellular reactive oxygen species (ROS) increased as well as cell cycle arrest predominantly at the G2/M phase observed. These results suggest that rotenoisin B might be a potent anticancer candidate similar to rotenone in hepatic cancer cells with low toxicity to normal cells even at high concentrations compared to rotenone. PMID:26213921

  17. Structure-antitussive activity relationships of naltrindole derivatives. Identification of novel and potent antitussive agents.

    PubMed

    Sakami, Satoshi; Maeda, Masayuki; Kawai, Koji; Aoki, Takumi; Kawamura, Kuniaki; Fujii, Hideaki; Hasebe, Ko; Nakajima, Mayumi; Endo, Takashi; Ueno, Shinya; Ito, Tsuyoshi; Kamei, Junzo; Nagase, Hiroshi

    2008-08-14

    We have previously reported antitussive effects of naltrindole (NTI), a typical delta opioid receptor antagonist, in a rat model. The ED50 values of NTI by intraperitoneal and peroral injections were 104 microg/kg and 1840 microg/kg, respectively, comparable to those of codeine. Codeine, one of the most reliable centrally acting antitussive drugs, has micro agonist activity and thus the same side effects as morphine, e.g., constipation, dependency, and respiratory depression. Because NTI is a delta opioid antagonist, its derivatives have potential as highly potent antitussives, free from the mu opioid agonist side effects. We attempted to optimize the NTI derivatives to develop novel antitussive agents. On the basis of the studies of structure-antitussive activity relationships of alkyl substituted NTI derivatives, we designed NTI derivatives with extra ring fused structures. As a clinical candidate, we identified a highly potent new compound, (5R,9R,13S,14S)-17-cyclopropylmethyl-6,7-didehydro-4,5-epoxy-5',6'-dihydro-3-methoxy-4'H-pyrrolo[3,2,1-ij]quinolino[2',1':6,7]morphinan-14-ol (5b) methanesulfonate (TRK-850) which was effective even by oral administration (ED50 6.40 microg/kg).

  18. Potent multitarget FAAH-COX inhibitors: Design and structure-activity relationship studies.

    PubMed

    Migliore, Marco; Habrant, Damien; Sasso, Oscar; Albani, Clara; Bertozzi, Sine Mandrup; Armirotti, Andrea; Piomelli, Daniele; Scarpelli, Rita

    2016-02-15

    Non-steroidal anti-inflammatory drugs (NSAIDs) exert their pharmacological effects by inhibiting cyclooxygenase (COX)-1 and COX-2. Though widely prescribed for pain and inflammation, these agents have limited utility in chronic diseases due to serious mechanism-based adverse events such as gastrointestinal damage. Concomitant blockade of fatty acid amide hydrolase (FAAH) enhances the therapeutic effects of the NSAIDs while attenuating their propensity to cause gastrointestinal injury. This favorable interaction is attributed to the accumulation of protective FAAH substrates, such as the endocannabinoid anandamide, and suggests that agents simultaneously targeting COX and FAAH might provide an innovative strategy to combat pain and inflammation with reduced side effects. Here, we describe the rational design and structure-active relationship (SAR) properties of the first class of potent multitarget FAAH-COX inhibitors. A focused SAR exploration around the prototype 10r (ARN2508) led to the identification of achiral (18b) as well as racemic (29a-c and 29e) analogs. Absolute configurational assignment and pharmacological evaluation of single enantiomers of 10r are also presented. (S)-(+)-10r is the first highly potent and selective chiral inhibitor of FAAH-COX with marked in vivo activity, and represents a promising lead to discover novel analgesics and anti-inflammatory drugs. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. Halogenated quinolines discovered through reductive amination with potent eradication activities against MRSA, MRSE and VRE biofilms.

    PubMed

    Basak, Akash; Abouelhassan, Yasmeen; Huigens, Robert W

    2015-11-07

    Small molecules capable of eradicating non-replicating bacterial biofilms are of great importance to human health as conventional antibiotics are ineffective against these surface-attached bacterial communities. Here, we report the discovery of several halogenated quinolines (HQs) identified through a reductive amination reaction that demonstrated potent eradication of MRSA (HQ-6; MBEC = 125 μM), MRSE (HQ-3; MBEC = 3.0 μM) and VRE (HQ-4, HQ-5 and HQ-6; MBEC = 1.0 μM) biofilms. HQs were evaluated using the Calgary Biofilm Device (CBD) and demonstrated near equipotent killing activities against planktonic and biofilm cells based on MBC and MBEC values. When tested against red blood cells, these HQ analogues demonstrated low haemolytic activity (3 to 21% at 200 μM) thus we conclude that these HQ analogues do not operate primarily through the destruction of bacterial membranes, typical of other biofilm-eradicating agents (i.e., antimicrobial peptides). HQ antibacterial agents are potent biofilm-eradicating compounds and could lead to useful treatments for biofilm-associated bacterial infections.

  20. CHS 828, a novel pyridyl cyanoguanidine with potent antitumor activity in vitro and in vivo.

    PubMed

    Hjarnaa, P J; Jonsson, E; Latini, S; Dhar, S; Larsson, R; Bramm, E; Skov, T; Binderup, L

    1999-11-15

    A new class of recently discovered antineoplastic agents, the pyridyl cyanoguanidines, exert a potent antitumor activity in rodents after oral administration. Optimization in vitro and in vivo has resulted in the selection of the lead candidate CHS 828 (N-(6-chlorophenoxyhexyl)-N'cyano-N"-4-pyridylguanidine). CHS 828 was found to exert potent cytotoxic effects in human breast and lung cancer cell lines, with lesser effects on normal fibroblasts and endothelial cells. In a study using a panel of cell lines with different resistance patterns, the effects of CHS 828 showed a low correlation with the activity patterns of known anticancer agents, and no sensitivity to known mechanisms of multidrug resistance was observed. In nude mice bearing human tumor xenografts, CHS 828, at doses from 20 to 50 mg/kg/day p.o., inhibited the growth of MCF-7 breast cancer tumors and caused regression of NYH small cell lung cancer tumors. Oral administration of CHS 828 once weekly improved efficacy without increasing toxicity. CHS 828 was found to compare favorably with established chemotherapeutic agents such as cyclophosphamide, etoposide, methotrexate, and paclitaxel. In mice with NYH tumors, long-term survival (>6 months) was observed after treatment with CHS 828 was stopped. In conclusion, CHS 828 is an effective new antitumor agent, with a potentially new mechanism of action. CHS 828 is presently being tested in Phase I clinical trials in collaboration with the European Organization for Research and Treatment of Cancer.

  1. Prokaryotic expression of a constitutively expressed Tephrosia villosa defensin and its potent antifungal activity.

    PubMed

    Vijayan, S; Guruprasad, Lalitha; Kirti, P B

    2008-10-01

    Plant defensins are small, highly stable, cysteine-rich antimicrobial peptides produced by the plants for inhibiting a broad-spectrum of microbial pathogens. Some of the well-characterized plant defensins exhibit potent antifungal activity on certain pathogenic fungal species only. We characterized a defensin, TvD1 from a weedy leguminous herb, Tephrosia villosa. The open reading frame of the cDNA was 228 bp, which codes for a peptide with 75 amino acids. Expression analyses indicated that this defensin is expressed constitutively in T. villosa with leaf, stem, root, and seed showing almost similar levels of high expression. The recombinant peptide (rTvD1), expressed in the Escherichia coli expression system, exhibited potent in vitro antifungal activity against several filamentous soil-borne fungal pathogens. The purified peptide also showed significant inhibition of root elongation in Arabidopsis seedlings, subsequently affecting the extension of growing root hairs indicating that it has the potential to disturb the plant growth and development.

  2. Recombinant Ad35 adenoviral proteins as potent modulators of human T-cell activation

    PubMed Central

    Hay, Joanne; Carter, Darrick; Lieber, André; Astier, Anne L

    2015-01-01

    The protein CD46 protects cells from complement attack by regulating cleavage of C3b and C3d. CD46 also regulates the adaptive immune response by controlling T-cell activation and differentiation. Co-engagement of the T-cell receptor and CD46 notably drives T-cell differentiation by switching production of interferon-γ to secretion of anti-inflammatory interleukin-10. This regulatory pathway is altered in several chronic inflammatory diseases, highlighting its key role for immune homeostasis. The manipulation of the CD46 pathway may therefore provide a powerful means to regulate immune responses. Herein, we investigated the effect of recombinant proteins derived from the fibre knob of the adenovirus serotype 35 (Ad35) that uses CD46 as its entry receptor, on human T-cell activation. We compared the effects of Ad35K++, engineered to exhibit enhanced affinity to CD46, and of Ad35K−, mutated in the binding site for CD46. Ad35K++ profoundly affects T-cell activation by decreasing the levels of CD46 at the surface of primary T cells, and impairing T-cell co-activation, shown by decreased CD25 expression, reduced proliferation and lower secretion of interleukin-10 and interferon-γ. In contrast, Ad35K− acts a potent co-activator of T cells, enhancing T-cell proliferation and cytokine production. These data show that recombinant Ad35 proteins are potent modulators of human T-cell activation, and support their further development as potential drugs targeting T-cell responses. PMID:25251258

  3. Dimers of melampomagnolide B exhibit potent anticancer activity against hematological and solid tumor cells

    PubMed Central

    Janganati, Venumadhav; Ponder, Jessica; Jordan, Craig T.; Borrelli, Michael J.; Penthala, Narsimha Reddy; Crooks, Peter A.

    2016-01-01

    A series of novel carbamate and carbonate dimers of melampomagnolide B (MMB) have been synthesized by reaction of the MMB-triazole carbamate synthon 6 with various terminal diamino and dihydroxy alkanes. The resulting dimeric products 7b, 7c and 7f were selected and evaluated for anticancer activity against a panel of 60 human hematological and solid tumor cell lines. The most active compounds, 7b, 7c and 7f, exhibited GI50 values in the range 250-780 nM against the majority of leukemia cell lines in the tumor cell panel. Specifically, compounds 7b and 7f exhibited potent growth inhibition against non-small cell lung cancer cell lines NCI-H522 (GI50 = 160 nM) and HOP-92 (GI50 = 170 nM), respectively. Also, compound 7f also potently inhibited the growth of melanoma cell lines LOX IMVI, MALME-3M, and UACC-62 (GI50 values = 170, 190 and 190 nM, respectively); breast cancer cell line MDA-MB-468 (GI50 = 190 nM); colon cancer cell line HCT-116 (GI50 = 190 nM); and renal cancer cell line RXF 393 (GI50 = 160 nM). Compound 7f and the simple dicarbonate dimer of MMB (8) showed anticancer activity 300-fold and 1 × 106-fold, respectively, more cytotoxic than 7f and DMAPT at a concentration of 10 μM against rat 9L-SF gliosarcoma cells. The dimeric compounds 7a-7j & 8 were also screened for antileukemic activity against M9-ENL1 acute myelogenous leukemia (AML) cells and primary AML cell specimens. These compounds exhibited two to twelve-fold more potent antileukemic activity (EC50 = 0.5-2.9 μM) against the M9-ENL1 cell line when compared to parthenolide (EC50 = 6.0 μM). The dimeric analogues were also active against the primary AML cell specimens in the nanomolar to lower micromolar range and exhibited two to ten-fold more potent antileukemic activity (EC50 = 0.86-4.2 μM) when compared to parthenolide (EC50 = 2.5-16 μM). Thus, dimer 7f exhibited promising anticancer activity against a variety of both hematological and solid human tumor cell lines, while dimer 8 was

  4. Potent Intratype Neutralizing Activity Distinguishes Human Immunodeficiency Virus Type 2 (HIV-2) from HIV-1

    PubMed Central

    Özkaya Şahin, Gülşen; Holmgren, Birgitta; da Silva, Zacarias; Nielsen, Jens; Nowroozalizadeh, Salma; Esbjörnsson, Joakim; Månsson, Fredrik; Andersson, Sören; Norrgren, Hans; Aaby, Peter

    2012-01-01

    HIV-2 has a lower pathogenicity and transmission rate than HIV-1. Neutralizing antibodies could be contributing to these observations. Here we explored side by side the potency and breadth of intratype and intertype neutralizing activity (NAc) in plasma of 20 HIV-1-, 20 HIV-2-, and 11 dually HIV-1/2 (HIV-D)-seropositive individuals from Guinea-Bissau, West Africa. Panels of primary isolates, five HIV-1 and five HIV-2 isolates, were tested in a plaque reduction assay using U87.CD4-CCR5 cells as targets. Intratype NAc in HIV-2 plasma was found to be considerably more potent and also broader than intratype NAc in HIV-1 plasma. This indicates that HIV-2-infected individuals display potent type-specific neutralizing antibodies, whereas such strong type-specific antibodies are absent in HIV-1 infection. Furthermore, the potency of intratype NAc was positively associated with the viral load of HIV-1 but not HIV-2, suggesting that NAc in HIV-1 infection is more antigen stimulation dependent than in HIV-2 infection, where plasma viral loads typically are at least 10-fold lower than in HIV-1 infection. Intertype NAc of both HIV-1 and HIV-2 infections was, instead, of low potency. HIV-D subjects had NAc to HIV-2 with similar high potency as singly HIV-2-infected individuals, whereas neutralization of HIV-1 remained poor, indicating that the difference in NAc between HIV-1 and HIV-2 infections depends on the virus itself. We suggest that immunogenicity and/or antigenicity, meaning the neutralization phenotype, of HIV-2 is distinct from that of HIV-1 and that HIV-2 may display structures that favor triggering of potent neutralizing antibody responses. PMID:22072782

  5. Potent anti-influenza activity of cyanovirin-N and interactions with viral hemagglutinin.

    PubMed

    O'Keefe, Barry R; Smee, Donald F; Turpin, Jim A; Saucedo, Carrie J; Gustafson, Kirk R; Mori, Toshiyuki; Blakeslee, Dennis; Buckheit, Robert; Boyd, Michael R

    2003-08-01

    The novel antiviral protein cyanovirin-N (CV-N) was initially discovered based on its potent activity against the human immunodeficiency virus (HIV). Subsequent studies identified the HIV envelope glycoproteins gp120 and gp41 as molecular targets of CV-N. More recently, mechanistic studies have shown that certain high-mannose oligosaccharides (oligomannose-8 and oligomannose-9) found on the HIV envelope glycoproteins comprise the specific sites to which CV-N binds. Such selective, carbohydrate-dependent interactions may account, at least in part, for the unusual and unexpected spectrum of antiviral activity of CV-N described herein. We screened CV-N against a broad range of respiratory and enteric viruses, as well as flaviviruses and herpesviruses. CV-N was inactive against rhinoviruses, human parainfluenza virus, respiratory syncytial virus, and enteric viruses but was moderately active against some herpesvirus and hepatitis virus (bovine viral diarrhea virus) strains (50% effective concentration [EC(50)] = approximately 1 micro g/ml) while inactive against others. Remarkably, however, CV-N and related homologs showed highly potent antiviral activity against almost all strains of influenza A and B virus, including clinical isolates and a neuraminidase inhibitor-resistant strain (EC(50) = 0.004 to 0.04 micro g/ml). When influenza virus particles were pretreated with CV-N, viral titers were lowered significantly (>1,000-fold). Further studies identified influenza virus hemagglutinin as a target for CV-N, showed that antiviral activity and hemagglutinin binding were correlated, and indicated that CV-N's interactions with hemagglutinin involved oligosaccharides. These results further reveal new potential avenues for antiviral therapeutics and prophylaxis targeting specific oligosaccharide-comprised sites on certain enveloped viruses, including HIV, influenza virus, and possibly others.

  6. The Second-Generation Exportin-1 Inhibitor KPT-8602 Demonstrates Potent Activity against Acute Lymphoblastic Leukemia.

    PubMed

    Vercruysse, Thomas; De Bie, Jolien; Neggers, Jasper E; Jacquemyn, Maarten; Vanstreels, Els; Schmid-Burgk, Jonathan L; Hornung, Veit; Baloglu, Erkan; Landesman, Yosef; Senapedis, William; Shacham, Sharon; Dagklis, Antonis; Cools, Jan; Daelemans, Dirk

    2016-10-25

    Purpose: Human exportin-1 (XPO1) is the key nuclear-cytoplasmic transport protein that exports different cargo proteins out of the nucleus. Inducing nuclear accumulation of these proteins by inhibiting XPO1 causes cancer cell death. First clinical validation of pharmacological inhibition of XPO1 was obtained with the Selective Inhibitor of Nuclear Export (SINE) compound selinexor (KPT-330) demonstrating activity in phase-II/IIb clinical trials when dosed 1 to 3 times weekly. The second-generation SINE compound KPT-8602 shows improved tolerability and can be dosed daily. Here, we investigate and validate the drug-target interaction of KPT-8602 and explore its activity against acute lymphoblastic leukemia (ALL).Experimental Design: We examined the effect of KPT-8602 on XPO1 function and XPO1-cargo as well as on a panel of leukemia cell lines. Mutant XPO1 leukemia cells were designed to validate KPT-8602's drug-target interaction. In vivo, anti-ALL activity was measured in a mouse ALL model and patient-derived ALL xenograft models.Results: KPT-8602 induced caspase-dependent apoptosis in a panel of leukemic cell lines in vitro Using CRISPR/Cas9 genome editing, we demonstrated the specificity of KPT-8602 for cysteine 528 in the cargo-binding groove of XPO1 and validated the drug target interaction. In vivo, KPT-8602 showed potent anti-leukemia activity in a mouse ALL model as well as in patient-derived T- and B-ALL xenograft models without affecting normal hematopoiesis.Conclusions: KPT-8602 is highly specific for XPO1 inhibition and demonstrates potent anti-leukemic activity supporting clinical application of the second-generation SINE compound for the treatment of ALL. Clin Cancer Res; 1-14. ©2016 AACR.

  7. Structure-Activity Relationships of Pentacyclic Triterpenoids as Potent and Selective Inhibitors against Human Carboxylesterase 1

    PubMed Central

    Zou, Li-Wei; Dou, Tong-Yi; Wang, Ping; Lei, Wei; Weng, Zi-Miao; Hou, Jie; Wang, Dan-Dan; Fan, Yi-Ming; Zhang, Wei-Dong; Ge, Guang-Bo; Yang, Ling

    2017-01-01

    Human carboxylesterase 1 (hCE1), one of the most important serine hydrolases distributed in liver and adipocytes, plays key roles in endobiotic homeostasis and xenobiotic metabolism. This study aimed to find potent and selective inhibitors against hCE1 from phytochemicals and their derivatives. To this end, a series of natural triterpenoids were collected and their inhibitory effects against human carboxylesterases (hCEs) were assayed using D-Luciferin methyl ester (DME) and 6,8-dichloro-9,9-dimethyl-7-oxo-7,9-dihydroacridin-2-yl benzoate (DDAB) as specific optical substrate for hCE1, and hCE2, respectively. Following screening of a series of natural triterpenoids, oleanolic acid (OA), and ursolic acid (UA) were found with strong inhibitory effects on hCE1 and relative high selectivity over hCE2. In order to get the highly selective and potent inhibitors of hCE1, a series of OA and UA derivatives were synthesized from OA and UA by chemical modifications including oxidation, reduction, esterification, and amidation. The inhibitory effects of these derivatives on hCEs were assayed and the structure-activity relationships of tested triterpenoids as hCE1 inhibitors were carefully investigated. The results demonstrated that the carbonyl group at the C-28 site is essential for hCE1 inhibition, the modifications of OA or UA at this site including esters, amides and alcohols are unbeneficial for hCE1 inhibition. In contrast, the structural modifications on OA and UA at other sites, such as converting the C-3 hydroxy group to 3-O-β-carboxypropionyl (compounds 20 and 22), led to a dramatically increase of the inhibitory effects against hCE1 and very high selectivity over hCE2. 3D-QSAR analysis of all tested triterpenoids including OA and UA derivatives provide new insights into the fine relationships linking between the inhibitory effects on hCE1 and the steric-electrostatic properties of triterpenoids. Furthermore, both inhibition kinetic analyses and docking simulations

  8. Structure-Activity Relationships of Pentacyclic Triterpenoids as Potent and Selective Inhibitors against Human Carboxylesterase 1.

    PubMed

    Zou, Li-Wei; Dou, Tong-Yi; Wang, Ping; Lei, Wei; Weng, Zi-Miao; Hou, Jie; Wang, Dan-Dan; Fan, Yi-Ming; Zhang, Wei-Dong; Ge, Guang-Bo; Yang, Ling

    2017-01-01

    Human carboxylesterase 1 (hCE1), one of the most important serine hydrolases distributed in liver and adipocytes, plays key roles in endobiotic homeostasis and xenobiotic metabolism. This study aimed to find potent and selective inhibitors against hCE1 from phytochemicals and their derivatives. To this end, a series of natural triterpenoids were collected and their inhibitory effects against human carboxylesterases (hCEs) were assayed using D-Luciferin methyl ester (DME) and 6,8-dichloro-9,9-dimethyl-7-oxo-7,9-dihydroacridin-2-yl benzoate (DDAB) as specific optical substrate for hCE1, and hCE2, respectively. Following screening of a series of natural triterpenoids, oleanolic acid (OA), and ursolic acid (UA) were found with strong inhibitory effects on hCE1 and relative high selectivity over hCE2. In order to get the highly selective and potent inhibitors of hCE1, a series of OA and UA derivatives were synthesized from OA and UA by chemical modifications including oxidation, reduction, esterification, and amidation. The inhibitory effects of these derivatives on hCEs were assayed and the structure-activity relationships of tested triterpenoids as hCE1 inhibitors were carefully investigated. The results demonstrated that the carbonyl group at the C-28 site is essential for hCE1 inhibition, the modifications of OA or UA at this site including esters, amides and alcohols are unbeneficial for hCE1 inhibition. In contrast, the structural modifications on OA and UA at other sites, such as converting the C-3 hydroxy group to 3-O-β-carboxypropionyl (compounds 20 and 22), led to a dramatically increase of the inhibitory effects against hCE1 and very high selectivity over hCE2. 3D-QSAR analysis of all tested triterpenoids including OA and UA derivatives provide new insights into the fine relationships linking between the inhibitory effects on hCE1 and the steric-electrostatic properties of triterpenoids. Furthermore, both inhibition kinetic analyses and docking simulations

  9. Impaired antigen presentation and potent phagocytic activity identifying tumor-tolerant human monocytes.

    PubMed

    Soares-Schanoski, Alessandra; Jurado, Teresa; Córdoba, Raúl; Siliceo, María; Fresno, Carlos Del; Gómez-Piña, Vanesa; Toledano, Victor; Vallejo-Cremades, Maria T; Alfonso-Iñiguez, Sergio; Carballo-Palos, Arkaitz; Fernández-Ruiz, Irene; Cubillas-Zapata, Carolina; Biswas, Subhra K; Arnalich, Francisco; García-Río, Francisco; López-Collazo, Eduardo

    2012-06-29

    Monocyte exposure to tumor cells induces a transient state in which these cells are refractory to further exposure to cancer. This phenomenon, termed "tumor tolerance", is characterized by a decreased production of proinflammatory cytokines in response to tumors. In the past, we found that this effect comprises IRAK-M up regulation and TLR4 and CD44 activation. Herein we have established a human model of tumor tolerance and have observed a marked down-regulation of MHCII molecules as well as the MHCII master regulator, CIITA, in monocytes/macrophages. These cells combine an impaired capability for antigen presentation with potent phagocytic activity and exhibit an M2-like phenotype. In addition circulating monocytes isolated from Chronic Lymphocytic Leukemia patients exhibited the same profile as tumor tolerant cells after tumor ex vivo exposition.

  10. Organotins Are Potent Activators of PPARγ and Adipocyte Differentiation in Bone Marrow Multipotent Mesenchymal Stromal Cells

    PubMed Central

    Yanik, Susan C.; Baker, Amelia H.; Mann, Koren K.; Schlezinger, Jennifer J.

    2011-01-01

    Adipocyte differentiation in bone marrow is potentially deleterious to both bone integrity and lymphopoiesis. Here, we examine the hypothesis that organotins, common environmental contaminants that are dual ligands for peroxisome proliferator–activated receptor (PPAR) γ and its heterodimerization partner retinoid X receptor (RXR), are potent activators of bone marrow adipogenesis. A C57Bl/6-derived bone marrow multipotent mesenchymal stromal cell (MSC) line, BMS2, was treated with rosiglitazone, a PPARγ agonist, bexarotene, an RXR agonist, or a series of organotins. Rosiglitazone and bexarotene potently activated adipocyte differentiation; however, bexarotene had a maximal efficacy of only 20% of that induced by rosiglitazone. Organotins (tributyltin [TBT], triphenyltin, and dibutyltin) also stimulated adipocyte differentiation (EC50 of 10–20nM) but with submaximal, structure-dependent efficacy. In coexposures, both bexarotene and TBT enhanced rosiglitazone-induced adipogenesis. To investigate the contribution of PPARγ to TBT-induced adipogenesis, we examined expression of PPARγ2, as well as its transcriptional target FABP4. TBT-induced PPARγ2 and FABP4 protein expression with an efficacy intermediate between rosiglitazone and bexarotene, similar to lipid accumulation. A PPARγ antagonist and PPARγ-specific small hairpin RNA suppressed TBT-induced differentiation, although to a lesser extent than rosiglitazone-induced differentiation, suggesting that TBT may engage alternate pathways. TBT and bexarotene, but not rosiglitazone, also induced the expression of TGM2 (an RXR target) and ABCA1 (a liver X receptor target). The results show that an environmental contaminant, acting with the same potency as a therapeutic drug, induces PPARγ-dependent adipocyte differentiation in bone marrow MSCs. Activation of multiple nuclear receptor pathways by organotins may have significant implications for bone physiology. PMID:21622945

  11. Organotins are potent activators of PPARγ and adipocyte differentiation in bone marrow multipotent mesenchymal stromal cells.

    PubMed

    Yanik, Susan C; Baker, Amelia H; Mann, Koren K; Schlezinger, Jennifer J

    2011-08-01

    Adipocyte differentiation in bone marrow is potentially deleterious to both bone integrity and lymphopoiesis. Here, we examine the hypothesis that organotins, common environmental contaminants that are dual ligands for peroxisome proliferator-activated receptor (PPAR) γ and its heterodimerization partner retinoid X receptor (RXR), are potent activators of bone marrow adipogenesis. A C57Bl/6-derived bone marrow multipotent mesenchymal stromal cell (MSC) line, BMS2, was treated with rosiglitazone, a PPARγ agonist, bexarotene, an RXR agonist, or a series of organotins. Rosiglitazone and bexarotene potently activated adipocyte differentiation; however, bexarotene had a maximal efficacy of only 20% of that induced by rosiglitazone. Organotins (tributyltin [TBT], triphenyltin, and dibutyltin) also stimulated adipocyte differentiation (EC₅₀ of 10-20 nM) but with submaximal, structure-dependent efficacy. In coexposures, both bexarotene and TBT enhanced rosiglitazone-induced adipogenesis. To investigate the contribution of PPARγ to TBT-induced adipogenesis, we examined expression of PPARγ2, as well as its transcriptional target FABP4. TBT-induced PPARγ2 and FABP4 protein expression with an efficacy intermediate between rosiglitazone and bexarotene, similar to lipid accumulation. A PPARγ antagonist and PPARγ-specific small hairpin RNA suppressed TBT-induced differentiation, although to a lesser extent than rosiglitazone-induced differentiation, suggesting that TBT may engage alternate pathways. TBT and bexarotene, but not rosiglitazone, also induced the expression of TGM2 (an RXR target) and ABCA1 (a liver X receptor target). The results show that an environmental contaminant, acting with the same potency as a therapeutic drug, induces PPARγ-dependent adipocyte differentiation in bone marrow MSCs. Activation of multiple nuclear receptor pathways by organotins may have significant implications for bone physiology.

  12. Potent anti-inflammatory activity of betulinic acid treatment in a model of lethal endotoxemia.

    PubMed

    Costa, José Fernando Oliveira; Barbosa-Filho, José Maria; Maia, Gabriela Lemos de Azevedo; Guimarães, Elisalva Teixeira; Meira, Cássio Santana; Ribeiro-dos-Santos, Ricardo; de Carvalho, Lain Carlos Pontes; Soares, Milena Botelho Pereira

    2014-12-01

    Betulinic acid (BA) is a lupane-type triterpene with a number of biological activities already reported. While potent anti-HIV and antitumoral activities were attributed to BA, it is considered to have a moderate anti-inflammatory activity. Here we evaluated the effects of BA in a mouse model of endotoxic shock. Endotoxemia was induced through intraperitoneally LPS administration, nitric oxide (NO) and cytokines were assessed by Griess method and ELISA, respectively. Treatment of BALB/c mice with BA at 67 mg/kg caused a 100% survival against a lethal dose of lipopolysaccharide (LPS). BA treatment caused a reduction in TNF-α production induced by LPS but did not alter IL-6 production. Moreover, BA treatment increased significantly the serum levels of IL-10 compared to vehicle-treated, LPS-challenged mice. To investigate the role of IL-10 in BA-induced protection, wild-type and IL-10(-/-) mice were studied. In contrast to the observations in IL-10(+/+) mice, BA did not protect IL-10(-/-) mice against a lethal LPS challenge. Addition of BA inhibited the production of pro-inflammatory mediators by macrophages stimulated with LPS, while promoting a significant increase in IL-10 production. BA-treated peritoneal exudate macrophages produced lower concentrations of TNF-α and NO and higher concentrations of IL-10 upon LPS stimulation. Similarly, macrophages obtained from BA-treated mice produced less pro-inflammatory mediators and increased IL-10 when compared to non-stimulated macrophages obtained from vehicle-treated mice. In conclusion, we have shown that BA has a potent anti-inflammatory activity in vivo, protecting mice against LPS by modulating TNF-α production by macrophages in vivo through a mechanism dependent on IL-10.

  13. Basic Tetrapeptides as Potent Intracellular Inhibitors of Type A Botulinum Neurotoxin Protease Activity*

    PubMed Central

    Hale, Martha; Oyler, George; Swaminathan, Subramanyam; Ahmed, S. Ashraf

    2011-01-01

    Botulinum neurotoxins (BoNT) are the most potent of all toxins that cause flaccid muscle paralysis leading to death. They are also potential biothreat agents. A systematic investigation of various short peptide inhibitors of the BoNT protease domain with a 17-residue peptide substrate led to arginine-arginine-glycine-cysteine having a basic tetrapeptide structure as the most potent inhibitor. When assayed in the presence of dithiothreitol (DTT), the inhibitory effect was drastically reduced. Replacing the terminal cysteine with one hydrophobic residue eliminated the DTT effect but with two hydrophobic residues made the pentapeptide a poor inhibitor. Replacing the first arginine with cysteine or adding an additional cysteine at the N terminus did not improve inhibition. When assessed using mouse brain lysates, the tetrapeptides also inhibited BoNT/A cleavage of the endogenous SNAP-25. The peptides penetrated the neuronal cell lines, N2A and BE(2)-M17, without adversely affecting metabolic functions as measured by ATP production and P-38 phosphorylation. Biological activity of the peptides persisted within cultured chick motor neurons and rat and mouse cerebellar neurons for more than 40 h and inhibited BoNT/A protease action inside the neurons in a dose- and time-dependent fashion. Our results define a tetrapeptide as the smallest peptide inhibitor in the backdrop of a large substrate protein of 200+ amino acids having multiple interaction regions with its cognate enzyme. The inhibitors should also be valuable candidates for drug development. PMID:20961849

  14. Basis Tetrapeptides as Potent Intracellular Inhibitors of type A Botulinum Neurotoxin Protease Activity

    SciTech Connect

    Hale, M.; Swaminathan, S.; Oyler, G.; Ahmed, S. A.

    2011-01-21

    Botulinum neurotoxins (BoNT) are the most potent of all toxins that cause flaccid muscle paralysis leading to death. They are also potential biothreat agents. A systematic investigation of various short peptide inhibitors of the BoNT protease domain with a 17-residue peptide substrate led to arginine-arginine-glycine-cysteine having a basic tetrapeptide structure as the most potent inhibitor. When assayed in the presence of dithiothreitol (DTT), the inhibitory effect was drastically reduced. Replacing the terminal cysteine with one hydrophobic residue eliminated the DTT effect but with two hydrophobic residues made the pentapeptide a poor inhibitor. Replacing the first arginine with cysteine or adding an additional cysteine at the N terminus did not improve inhibition. When assessed using mouse brain lysates, the tetrapeptides also inhibited BoNT/A cleavage of the endogenous SNAP-25. The peptides penetrated the neuronal cell lines, N2A and BE(2)-M17, without adversely affecting metabolic functions as measured by ATP production and P-38 phosphorylation. Biological activity of the peptides persisted within cultured chick motor neurons and rat and mouse cerebellar neurons for more than 40 h and inhibited BoNT/A protease action inside the neurons in a dose- and time-dependent fashion. Our results define a tetrapeptide as the smallest peptide inhibitor in the backdrop of a large substrate protein of 200+ amino acids having multiple interaction regions with its cognate enzyme. The inhibitors should also be valuable candidates for drug development.

  15. Novel highly potent and selective nonsteroidal aromatase inhibitors: synthesis, biological evaluation and structure-activity relationships investigation.

    PubMed

    Gobbi, Silvia; Zimmer, Christina; Belluti, Federica; Rampa, Angela; Hartmann, Rolf W; Recanatini, Maurizio; Bisi, Alessandra

    2010-07-22

    In further pursuing our search for potent and selective aromatase inhibitors, a new series of molecules was designed and synthesized, exploring possible structural modifications of a previously identified xanthone scaffold. Among them, highly potent compounds, with inhibitory activity in the low nanomolar range, were found. In particular, substitution of the heterocyclic oxygen atom in the xanthone core by a sulfur atom and/or increase in structure flexibility seemed to be favorable for the interaction with the enzyme.

  16. Allergy-Inducing Chromium Compounds Trigger Potent Innate Immune Stimulation Via ROS-Dependent Inflammasome Activation.

    PubMed

    Adam, Christian; Wohlfarth, Jonas; Haußmann, Maike; Sennefelder, Helga; Rodin, Annette; Maler, Mareike; Martin, Stefan F; Goebeler, Matthias; Schmidt, Marc

    2017-02-01

    Chromium allergy is a common occupational skin disease mediated by chromium (VI)-specific T cells that induce delayed-type hypersensitivity in sensitized individuals. Additionally, chromium (VI) can act as an irritant. Both responses critically require innate immune activation, but if and how chromium (VI) elicits this signal is currently unclear. Using human monocytes, primary human keratinocytes, and murine dendritic cells we show that chromium (VI) compounds fail to trigger direct proinflammatory activation but potently induce processing and secretion of IL-1β. IL-1β release required priming by phorbol-ester or toll-like receptor stimulation and was prevented by inhibition of K(+) efflux, NLRP3 depletion or caspase-1 inhibition, identifying chromium (VI) as a hapten activator of the NLRP3 inflammasome. Inflammasome activation was initiated by mitochondrial reactive oxygen species production triggered by chromium (VI), as indicated by sensitivity to treatment with the ROS scavenger N-acetyl cysteine and a coinciding failure of K(+) efflux, caspase-1, or NLRP3 inhibition to prevent mitochondrial reactive oxygen species accumulation. IL-1β release further correlated with cytotoxicity that was secondary to reactive oxygen species, K(+) efflux, and NLRP3 activation. Trivalent chromium was unable to induce mitochondrial reactive oxygen species production, inflammasome activation, and cytotoxicity, suggesting that oxidation state-specific differences in mitochondrial reactivity may determine inflammasome activation and allergic/irritant capacity of different chromium compounds.

  17. Potent SIRT1 enzyme-stimulating and anti-glycation activities of polymethoxyflavonoids from Kaempferia parviflora.

    PubMed

    Nakata, Asami; Koike, Yuka; Matsui, Hirofumi; Shimadad, Tsutomu; Aburada, Masaki; Yang, Jinwei

    2014-09-01

    The SIRT1 enzyme-stimulating and anti-glycation activities of Kaempferia parviflora extract and its main polymethoxyflavonoids were evaluated in vitro. K. parviflora extract elevated SIRT1 catalytic activity by eight- and 17-fold at 20 μg/mL and 100 μg/mL, respectively, compared with vehicle only. Two major polymethoxyflavonoids, 3,5,7,3',4'-pentamethoxyflavone (4) and 5,7,4'-trimethoxyflavone (5), were isolated from this extract and are four- and fivefold more potent than resveratrol, hitherto the strongest known natural SIRT1 activator. In addition, the anti-glycation activity of K. parviflora extract was observed to be seven times more effective than aminoguanidine, a clinical anti-diabetes drug. 3,5,7,3',4'-Pentamethoxyflavone (4) and 5,7,4'-trimethoxyflavone (5) showed the strongest anti-glycation activity among the tested polymethoxyflavonoids. Further comparison of the activity of these structurally related polymethoxyflavonoids revealed a possible structure-activity relationship, in particular, for the contribution of methoxy moieties.

  18. Potent inhibition by star fruit of human cytochrome P450 3A (CYP3A) activity.

    PubMed

    Hidaka, Muneaki; Fujita, Ken-ichi; Ogikubo, Tetsuya; Yamasaki, Keishi; Iwakiri, Tomomi; Okumura, Manabu; Kodama, Hirofumi; Arimori, Kazuhiko

    2004-06-01

    There has been very limited information on the capacities of tropical fruits to inhibit human cytochrome P450 3A (CYP3A) activity. Thus, the inhibitory effects of tropical fruits on midazolam 1'-hydroxylase activity of CYP3A in human liver microsomes were evaluated. Eight tropical fruits such as common papaw, dragon fruit, kiwi fruit, mango, passion fruit, pomegranate, rambutan, and star fruit were tested. We also examined the inhibition of CYP3A activity by grapefruit (white) and Valencia orange as controls. The juice of star fruit showed the most potent inhibition of CYP3A. The addition of a star fruit juice (5.0%, v/v) resulted in the almost complete inhibition of midazolam 1'-hydroxylase activity (residual activity of 0.1%). In the case of grape-fruit, the residual activity was 14.7%. The inhibition depended on the amount of fruit juice added to the incubation mixture (0.2-6.0%, v/v). The elongation of the preincubation period of a juice from star fruit (1.25 or 2.5%, v/v) with the microsomal fraction did not alter the CYP3A inhibition, suggesting that the star fruit did not contain a mechanism-based inhibitor. Thus, we discovered filtered extracts of star fruit juice to be inhibitors of human CYP3A activity in vitro.

  19. The EDLL motif: a potent plant transcriptional activation domain from AP2/ERF transcription factors.

    PubMed

    Tiwari, Shiv B; Belachew, Alemu; Ma, Siu Fong; Young, Melinda; Ade, Jules; Shen, Yu; Marion, Colleen M; Holtan, Hans E; Bailey, Adina; Stone, Jeffrey K; Edwards, Leslie; Wallace, Andreah D; Canales, Roger D; Adam, Luc; Ratcliffe, Oliver J; Repetti, Peter P

    2012-06-01

    In plants, the ERF/EREBP family of transcriptional regulators plays a key role in adaptation to various biotic and abiotic stresses. These proteins contain a conserved AP2 DNA-binding domain and several uncharacterized motifs. Here, we describe a short motif, termed 'EDLL', that is present in AtERF98/TDR1 and other clade members from the same AP2 sub-family. We show that the EDLL motif, which has a unique arrangement of acidic amino acids and hydrophobic leucines, functions as a strong activation domain. The motif is transferable to other proteins, and is active at both proximal and distal positions of target promoters. As such, the EDLL motif is able to partly overcome the repression conferred by the AtHB2 transcription factor, which contains an ERF-associated amphiphilic repression (EAR) motif. We further examined the activation potential of EDLL by analysis of the regulation of flowering time by NF-Y (nuclear factor Y) proteins. Genetic evidence indicates that NF-Y protein complexes potentiate the action of CONSTANS in regulation of flowering in Arabidopsis; we show that the transcriptional activation function of CONSTANS can be substituted by direct fusion of the EDLL activation motif to NF-YB subunits. The EDLL motif represents a potent plant activation domain that can be used as a tool to confer transcriptional activation potential to heterologous DNA-binding proteins.

  20. Aplidin, a marine organism-derived compound with potent antimyeloma activity in vitro and in vivo.

    PubMed

    Mitsiades, Constantine S; Ocio, Enrique M; Pandiella, Atanasio; Maiso, Patricia; Gajate, Consuelo; Garayoa, Mercedes; Vilanova, David; Montero, Juan Carlos; Mitsiades, Nicholas; McMullan, Ciaran J; Munshi, Nikhil C; Hideshima, Teru; Chauhan, Dharminder; Aviles, Pablo; Otero, Gabriel; Faircloth, Glynn; Mateos, M Victoria; Richardson, Paul G; Mollinedo, Faustino; San-Miguel, Jesus F; Anderson, Kenneth C

    2008-07-01

    Despite recent progress in its treatment, multiple myeloma (MM) remains incurable, thus necessitating identification of novel anti-MM agents. We report that the marine-derived cyclodepsipeptide Aplidin exhibits, at clinically achievable concentrations, potent in vitro activity against primary MM tumor cells and a broad spectrum of human MM cell lines, including cells resistant to conventional (e.g., dexamethasone, alkylating agents, and anthracyclines) or novel (e.g., thalidomide and bortezomib) anti-MM agents. Aplidin is active against MM cells in the presence of proliferative/antiapoptotic cytokines or bone marrow stromal cells and has additive or synergistic effects with some of the established anti-MM agents. Mechanistically, a short in vitro exposure to Aplidin induces MM cell death, which involves activation of p38 and c-jun NH(2)-terminal kinase signaling, Fas/CD95 translocation to lipid rafts, and caspase activation. The anti-MM effect of Aplidin is associated with suppression of a constellation of proliferative/antiapoptotic genes (e.g., MYC, MYBL2, BUB1, MCM2, MCM4, MCM5, and survivin) and up-regulation of several potential regulators of apoptosis (including c-JUN, TRAIL, CASP9, and Smac). Aplidin exhibited in vivo anti-MM activity in a mouse xenograft model. The profile of the anti-MM activity of Aplidin in our preclinical models provided the framework for its clinical testing in MM, which has already provided favorable preliminary results.

  1. Potent antagonistic activity of Egyptian Lactobacillus plantarum against multiresistant and virulent food-associated pathogens

    PubMed Central

    Al-Madboly, Lamiaa A.; Abdullah, Abeer K.

    2015-01-01

    Recent years have shown a growing interest to replace the administration of antibiotics with the application of probiotics. The aim of our investigation was to screen for promising strains with broad antimicrobial activity and also more resistant to the challenges met in the gastrointestinal tract. In our study, only 32 out of 50 (64%) probiotic isolates showed antagonistic activity against certain major extensively and pandrug-resistant Gram-positive and -negative food-borne pathogens. Fifteen L. plantarum isolates had a broad antibacterial spectrum. Among these isolates, only five presented potent antibacterial activity relative to previous studies. The recorded inhibition zone diameter ranged from 25 to 44 mm. Pronounced cell-free supernatant activities (6400–25,600 AU/ml) were commonly detected at the end of the logarithmic phase at 37°C. A marked increase in the range of activity (12,800–51,200 AU/ml) was recorded after the addition of 0.9% Na Cl to the media. Moreover, subjecting these isolates to different stressors, including high temperature, low pH, and different concentrations of bile and Na Cl, revealed different responses, and only two out of the five L. plantarum isolates showed marked resistance to all of the stress factors. Accordingly, this study highlights the intense and broad antagonistic activity induced by L. plantarum against various food associated pathogens, and their ability to resist different stressors suggests that they can be used in the food and pharmaceutical industry. PMID:26029169

  2. Potent and selective MAO-B inhibitory activity: amino- versus nitro-3-arylcoumarin derivatives.

    PubMed

    Matos, Maria João; Rodríguez-Enríquez, Fernanda; Vilar, Santiago; Santana, Lourdes; Uriarte, Eugenio; Hripcsak, George; Estrada, Martín; Rodríguez-Franco, María Isabel; Viña, Dolores

    2015-02-01

    In this study we synthesized and evaluated a new series of amino and nitro 3-arylcoumarins as hMAO-A and hMAO-B inhibitors. Compounds 2, 3, 5 and 6 presented a better activity and selectivity profile against the hMAO-B isoform (IC50 values between 2 and 6nM) than selegiline. In general, the amino derivatives (4-6) proved to be more selective against MAO-B than the nitro derivatives (1-3). Additionally, a theoretical study of some physicochemical properties, PAMPA and reversibility assays for the most potent derivative, and molecular docking simulations were carried out to further explain the pharmacological results, and to identify the hypothetical binding mode for the compounds inside the hMAO-B. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Galloylated proanthocyanidins from shea (Vitellaria paradoxa) meal have potent anthelmintic activity against Ascaris suum.

    PubMed

    Ramsay, A; Williams, A R; Thamsborg, S M; Mueller-Harvey, I

    2016-02-01

    Proanthocyanidins (PA) from shea (Vitellaria paradoxa) meal were investigated by thiolytic degradation with benzyl mercaptan and the reaction products were analysed by high performance liquid chromatography-mass spectrometry. These PA were galloylated (≈40%), contained only B-type linkages and had a high proportion of prodelphinidins (>70%). The mean degree of polymerisation was 8 (i.e. average molecular size was 2384Da) and epigallocatechin gallate (EGCg) was the major flavan-3-ol subunit in PA. Shea meal also proved to be a potentially valuable source for extracting free flavan-3-ol-O-gallates, especially EGCg (575mg/kg meal), which is known for its health and anti-parasitic benefits. Proanthocyanidins were isolated and tested for bioactivity against Ascaris suum, which is an important parasite of pigs. Migration and motility tests revealed that these PA have potent activity against this parasitic nematode.

  4. Designed, synthetically accessible bryostatin analogues potently induce activation of latent HIV reservoirs in vitro.

    PubMed

    DeChristopher, Brian A; Loy, Brian A; Marsden, Matthew D; Schrier, Adam J; Zack, Jerome A; Wender, Paul A

    2012-09-01

    Bryostatin is a unique lead in the development of potentially transformative therapies for cancer, Alzheimer's disease and the eradication of HIV/AIDS. However, the clinical use of bryostatin has been hampered by its limited supply, difficulties in accessing clinically relevant derivatives, and side effects. Here, we address these problems through the step-economical syntheses of seven members of a new family of designed bryostatin analogues using a highly convergent Prins-macrocyclization strategy. We also demonstrate for the first time that such analogues effectively induce latent HIV activation in vitro with potencies similar to or better than bryostatin. Significantly, these analogues are up to 1,000-fold more potent in inducing latent HIV expression than prostratin, the current clinical candidate for latent virus induction. This study provides the first demonstration that designed, synthetically accessible bryostatin analogues could serve as superior candidates for the eradication of HIV/AIDS through induction of latent viral reservoirs in conjunction with current antiretroviral therapy.

  5. Designed, synthetically accessible bryostatin analogues potently induce activation of latent HIV reservoirs in vitro

    NASA Astrophysics Data System (ADS)

    Dechristopher, Brian A.; Loy, Brian A.; Marsden, Matthew D.; Schrier, Adam J.; Zack, Jerome A.; Wender, Paul A.

    2012-09-01

    Bryostatin is a unique lead in the development of potentially transformative therapies for cancer, Alzheimer's disease and the eradication of HIV/AIDS. However, the clinical use of bryostatin has been hampered by its limited supply, difficulties in accessing clinically relevant derivatives, and side effects. Here, we address these problems through the step-economical syntheses of seven members of a new family of designed bryostatin analogues using a highly convergent Prins-macrocyclization strategy. We also demonstrate for the first time that such analogues effectively induce latent HIV activation in vitro with potencies similar to or better than bryostatin. Significantly, these analogues are up to 1,000-fold more potent in inducing latent HIV expression than prostratin, the current clinical candidate for latent virus induction. This study provides the first demonstration that designed, synthetically accessible bryostatin analogues could serve as superior candidates for the eradication of HIV/AIDS through induction of latent viral reservoirs in conjunction with current antiretroviral therapy.

  6. Discovery of HDAC Inhibitors with Potent Activity Against Multiple Malaria Parasite Life Cycle Stages

    PubMed Central

    Hansen, Finn K.; Sumanadasa, Subathdrage D. M.; Stenzel, Katharina; Duffy, Sandra; Meister, Stephan; Marek, Linda; Schmetter, Rebekka; Kuna, Krystina; Hamacher, Alexandra; Mordmüller, Benjamin; Kassack, Matthias U.; Winzeler, Elizabeth A.; Avery, Vicky M.; Andrews, Katherine T.; Kurz, Thomas

    2015-01-01

    In this work we investigated the antiplasmodial activity of a series of HDAC inhibitors containing an alkoxyamide connecting-unit linker region. HDAC inhibitor 1a (LMK235), previously shown to be a novel and specific inhibitor of human HDAC4 and 5, was used as a starting point to rapidly construct a mini-library of HDAC inhibitors using a straightforward solid-phase supported synthesis. Several of these novel HDAC inhibitors were found to have potent in vitro activity against asexual stage P. falciparum malaria parasites. Representative compounds were shown to hyperacetylate P. falciparum histones and to inhibit deacetylase activity of recombinant PfHDAC1 and P. falciparum nuclear extracts. All compounds were also screened in vitro for activity against P. berghei exo-erythrocytic stages and selected compounds were further tested against late stage (IV and V) P. falciparum gametocytes. Of note, some compounds showed nanomolar activity against all three life cycle stages tested (asexual, exo-erythrocytic and gametocyte stages) and several compounds displayed significantly increased parasite selectivity compared to the reference HDAC inhibitor suberoylanilide hydroxamic acid (SAHA). These data suggest that it may be possible to develop HDAC inhibitors that target multiple malaria parasite life cycle stages. PMID:24904967

  7. A non-cytotoxic N-dehydroabietylamine derivative with potent antimalarial activity.

    PubMed

    Sadashiva, Maralinganadoddi P; Gowda, Raghavendra; Wu, Xianzhu; Inamdar, Gajanan S; Kuzu, Omer F; Rangappa, Kanchugarakoppal S; Robertson, Gavin P; Gowda, D Channe

    2015-08-01

    Malaria caused by the Plasmodium parasites continues to be an enormous global health problem owing to wide spread drug resistance of parasites to many of the available antimalarial drugs. Therefore, development of new classes of antimalarial agents is essential to effectively treat malaria. In this study, the efficacy of naturally occurring diterpenoids, dehydroabietylamine and abietic acid, and their synthetic derivatives was assessed for antimalarial activity. Dehydroabietylamine and its N-trifluoroacetyl, N-tribromoacetyl, N-benzoyl, and N-benzyl derivatives showed excellent activity against P. falciparum parasites with IC50 values of 0.36 to 2.6 µM. Interestingly, N-dehydroabietylbenzamide showed potent antimalarial activity (IC50 0.36), and negligible cytotoxicity (IC50 >100 µM) to mammalian cells; thus, this compound can be an important antimalarial drug. In contrast, abietic acid was only marginally effective, exhibiting an IC50 value of ~82 µM. Several carboxylic group-derivatives of abietic acid were moderately active with IC50 values of ~8.2 to ~13.3 µM. These results suggest that a detailed understanding of the structure-activity relationship of abietane diterpenoids might provide strategies to exploit this class of compounds for malaria treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Pyrazole derived ultra-short antimicrobial peptidomimetics with potent anti-biofilm activity.

    PubMed

    Ahn, Mija; Gunasekaran, Pethaiah; Rajasekaran, Ganesan; Kim, Eun Young; Lee, Soo-Jae; Bang, Geul; Cho, Kun; Hyun, Jae-Kyung; Lee, Hyun-Ju; Jeon, Young Ho; Kim, Nam-Hyung; Ryu, Eun Kyoung; Shin, Song Yub; Bang, Jeong Kyu

    2017-01-05

    In this study, we report on the first chemical synthesis of ultra-short pyrazole-arginine based antimicrobial peptidomimetics derived from the newly synthesized N-alkyl/aryl pyrazole amino acids. Through the systematic tuning of hydrophobicity, charge, and peptide length, we identified the shortest peptide Py11 with the most potent antimicrobial activity. Py11 displayed greater antimicrobial activity against antibiotic-resistant bacteria, including MRSA, MDRPA, and VREF, which was approximately 2-4 times higher than that of melittin. Besides its higher selectivity (therapeutic index) toward bacterial cells than LL-37, Py11 showed highly increased proteolytic stability against trypsin digestion and maintained its antimicrobial activity in the presence of physiological salts. Interestingly, Py11 exhibited higher anti-biofilm activity against MDRPA compared to LL-37. The results from fluorescence spectroscopy and transmission electron microscopy (TEM) suggested that Py11 kills bacterial cells possibly by integrity disruption damaging the cell membrane, leading to the cytosol leakage and eventual cell lysis. Furthermore, Py11 displayed significant anti-inflammatory (endotoxin-neutralizing) activity by inhibiting LPS-induced production of nitric oxide (NO) and TNF-α. Collectively, our results suggest that Py11 may serve as a model compound for the design of antimicrobial and antisepsis agents.

  9. Sulfonylureas have antifungal activity and are potent inhibitors of Candida albicans acetohydroxyacid synthase.

    PubMed

    Lee, Yu-Ting; Cui, Chang-Jun; Chow, Eve W L; Pue, Nason; Lonhienne, Thierry; Wang, Jian-Guo; Fraser, James A; Guddat, Luke W

    2013-01-10

    The sulfonylurea herbicides exert their activity by inhibiting plant acetohydroxyacid synthase (AHAS), the first enzyme in the branched-chain amino acid biosynthesis pathway. It has previously been shown that if the gene for AHAS is deleted in Candida albicans , attenuation of virulence is achieved, suggesting AHAS as an antifungal drug target. Herein, we have cloned, expressed, and purified C. albicans AHAS and shown that several sulfonylureas are inhibitors of this enzyme and possess antifungal activity. The most potent of these compounds is ethyl 2-(N-((4-iodo-6-methoxypyrimidin-2-yl)carbamoyl)sulfamoyl)benzoate (10c), which has a K(i) value of 3.8 nM for C. albicans AHAS and an MIC₉₀ of 0.7 μg/mL for this fungus in cell-based assays. For the sulfonylureas tested there was a strong correlation between inhibitory activity toward C. albicans AHAS and fungicidal activity, supporting the hypothesis that AHAS is the target for their inhibitory activity within the cell.

  10. MIV-150 and zinc acetate combination provides potent and broad activity against HIV-1.

    PubMed

    Mizenina, Olga; Hsu, Mayla; Jean-Pierre, Ninochka; Aravantinou, Meropi; Levendosky, Keith; Paglini, Gabriela; Zydowsky, Thomas M; Robbiani, Melissa; Fernández-Romero, José A

    2017-08-15

    We previously showed that the combination of the non-nucleoside reverse transcriptase inhibitor (NNRTI) MIV-150 with zinc acetate (ZA) formulated in a carrageenan (CG; MZC) gel provided macaques significant protection against vaginal simian-human immunodeficiency virus-RT (SHIV-RT) challenge, better than either MIV-150/CG or ZA/CG. The MZC gel was shown to be safe in a phase 1 clinical trial. Herein, we used in vitro approaches to study the antiviral properties of ZA and the MIV-150/ZA combination, compared to other NNRTIs. Like other NNRTIs, MIV-150 has EC50 values in the subnanomolar to nanomolar range against wild type and NNRTI or RT-resistant HIVs. While less potent than NNRTIs, ZA was shown to be active in primary cells against laboratory-adapted and primary HIV-1 isolates and HIV-1 isolates/clones with NNRTI and RT resistance mutations, with EC50 values between 20 and 110 μM. The MIV-150/ZA combination had a potent and broad antiviral activity in primary cells. In vitro resistance selection studies revealed that previously described NNRTI-resistant mutations were selected by MIV-150. ZA-resistant virus retained susceptibility to MIV-150 (and other RTIs) and MIV-150-selected virus remained sensitive to ZA. Notably, resistant virus was not selected when cultured in the presence of both ZA and MIV-150. This underscores the potency and breadth of the MIV-150/ZA combination, supporting preclinical macaque studies and the advancement of MZC microbicides into clinical testing.

  11. Alkyl Amine Bevirimat Derivatives Are Potent and Broadly Active HIV-1 Maturation Inhibitors

    PubMed Central

    Urano, Emiko; Ablan, Sherimay D.; Mandt, Rebecca; Pauly, Gary T.; Sigano, Dina M.; Schneider, Joel P.; Martin, David E.; Nitz, Theodore J.; Wild, Carl T.

    2015-01-01

    Concomitant with the release of human immunodeficiency virus type 1 (HIV-1) particles from the infected cell, the viral protease cleaves the Gag polyprotein precursor at a number of sites to trigger virus maturation. We previously reported that a betulinic acid-derived compound, bevirimat (BVM), blocks HIV-1 maturation by disrupting a late step in protease-mediated Gag processing: the cleavage of the capsid-spacer peptide 1 (CA-SP1) intermediate to mature CA. BVM was shown in multiple clinical trials to be safe and effective in reducing viral loads in HIV-1-infected patients. However, naturally occurring polymorphisms in the SP1 region of Gag (e.g., SP1-V7A) led to a variable response in some BVM-treated patients. The reduced susceptibility of SP1-polymorphic HIV-1 to BVM resulted in the discontinuation of its clinical development. To overcome the loss of BVM activity induced by polymorphisms in SP1, we carried out an extensive medicinal chemistry campaign to develop novel maturation inhibitors. In this study, we focused on alkyl amine derivatives modified at the C-28 position of the BVM scaffold. We identified a set of derivatives that are markedly more potent than BVM against an HIV-1 clade B clone (NL4-3) and show robust antiviral activity against a variant of NL4-3 containing the V7A polymorphism in SP1. One of the most potent of these compounds also strongly inhibited a multiclade panel of primary HIV-1 isolates. These data demonstrate that C-28 alkyl amine derivatives of BVM can, to a large extent, overcome the loss of susceptibility imposed by polymorphisms in SP1. PMID:26482309

  12. Novel 3-Oxazolidinedione-6-aryl-pyridinones as Potent, Selective, and Orally Active EP3 Receptor Antagonists.

    PubMed

    Jin, Jian; Morales-Ramos, Angel; Eidam, Patrick; Mecom, John; Li, Yue; Brooks, Carl; Hilfiker, Mark; Zhang, David; Wang, Ning; Shi, Dongchuan; Tseng, Pei-San; Wheless, Karen; Budzik, Brian; Evans, Karen; Jaworski, Jon-Paul; Jugus, Jack; Leon, Lisa; Wu, Charlene; Pullen, Mark; Karamshi, Bhumika; Rao, Parvathi; Ward, Emma; Laping, Nicholas; Evans, Christopher; Leach, Colin; Holt, Dennis; Su, Xin; Morrow, Dwight; Fries, Harvey; Thorneloe, Kevin; Edwards, Richard

    2010-10-14

    High-throughput screening and subsequent optimization led to the discovery of novel 3-oxazolidinedione-6-aryl-pyridinones exemplified by compound 2 as potent and selective EP3 antagonists with excellent pharmacokinetic properties. Compound 2 was orally active and showed robust in vivo activities in overactive bladder models. To address potential bioactivation liabilities of compound 2, further optimization resulted in compounds 9 and 10, which maintained excellent potency, selectivity, and pharmacokinetic properties and showed no bioactivation liability in glutathione trapping studies. These highly potent, selective, and orally active EP3 antagonists are excellent tool compounds for investigating and validating potential therapeutic benefits from selectively inhibiting the EP3 receptor.

  13. Aminothiazoles as Potent and Selective Sirt2 Inhibitors: A Structure-Activity Relationship Study.

    PubMed

    Schiedel, Matthias; Rumpf, Tobias; Karaman, Berin; Lehotzky, Attila; Oláh, Judit; Gerhardt, Stefan; Ovádi, Judit; Sippl, Wolfgang; Einsle, Oliver; Jung, Manfred

    2016-02-25

    Sirtuins are NAD(+)-dependent protein deacylases that cleave off acetyl but also other acyl groups from the ε-amino group of lysines in histones and other substrate proteins. Dysregulation of human Sirt2 (hSirt2) activity has been associated with the pathogenesis of cancer, inflammation, and neurodegeneration, which makes the modulation of hSirt2 activity a promising strategy for pharmaceutical intervention. The sirtuin rearranging ligands (SirReals) have recently been discovered by us as highly potent and isotype-selective hSirt2 inhibitors. Here, we present a well-defined structure-activity relationship study, which rationalizes the unique features of the SirReals and probes the limits of modifications on this scaffold regarding inhibitor potency. Moreover, we present a crystal structure of hSirt2 in complex with an optimized SirReal derivative that exhibits an improved in vitro activity. Lastly, we show cellular hyperacetylation of the hSirt2 targeted tubulin caused by our improved lead structure.

  14. Thiazole: a promising heterocycle for the development of potent CNS active agents.

    PubMed

    Mishra, Chandra Bhushan; Kumari, Shikha; Tiwari, Manisha

    2015-03-06

    Thiazole is a valuable scaffold in the field of medicinal chemistry and has accounted to display a variety of biological activities. Thiazole and its derivatives have attracted continuing interest to design various novel CNS active agents. In the past few decades, thiazoles have been widely used to develop a variety of therapeutic agents against numerous CNS targets. Thiazole containing drug molecules are currently being used in treatment of various CNS disorders and a number of thiazole derivatives are also presently in clinical trials. A lot of research has been carried out on thiazole and their analogues, which has proved their efficacy to overcome several CNS disorders in rodent as well as primate models. The aim of present review is to highlights diverse CNS activities displayed by thiazole and their derivatives. SAR of this nucleus has also been well discussed. This review covers the recent updates present in literature and will surely provide a greater insight for the designing and development of potent thiazole based CNS active agents in future.

  15. A chalcone with potent inhibiting activity against biofilm formation by nontypeable Haemophilus influenzae.

    PubMed

    Kunthalert, Duangkamol; Baothong, Sudarat; Khetkam, Pichit; Chokchaisiri, Suwadee; Suksamrarn, Apichart

    2014-10-01

    Nontypeable Haemophilus influenzae (NTHi), an important human respiratory pathogen, frequently causes biofilm infections. Currently, resistance of bacteria within the biofilm to conventional antimicrobials poses a major obstacle to effective medical treatment on a global scale. Novel agents that are effective against NTHi biofilm are therefore urgently required. In this study, a series of natural and synthetic chalcones with various chemical substituents were evaluated in vitro for their antibiofilm activities against strong biofilm-forming strains of NTHi. Of the test chalcones, 3-hydroxychalcone (chalcone 8) exhibited the most potent inhibitory activity, its mean minimum biofilm inhibitory concentration (MBIC50 ) being 16 μg/mL (71.35 μM), or approximately sixfold more active than the reference drug, azithromycin (MBIC50 419.68 μM). The inhibitory activity of chalcone 8, which is a chemically modified chalcone, appeared to be superior to those of the natural chalcones tested. Significantly, chalcone 8 inhibited biofilm formation by all studied NTHi strains, indicating that the antibiofilm activities of this compound occur across multiple strong-biofilm forming NTHi isolates of different clinical origins. According to antimicrobial and growth curve assays, chalcone 8 at concentrations that decreased biofilm formation did not affect growth of NTHi, suggesting the biofilm inhibitory effect of chalcone 8 is non-antimicrobial. In terms of structure-activity relationship, the possible substituent on the chalcone backbone required for antibiofilm activity is discussed. These findings indicate that 3-hydroxychalcone (chalcone 8) has powerful antibiofilm activity and suggest the potential application of chalcone 8 as a new therapeutic agent for control of NTHi biofilm-associated infections.

  16. The potent antioxidant activity of the vitamin K cycle in microsomal lipid peroxidation.

    PubMed

    Vervoort, L M; Ronden, J E; Thijssen, H H

    1997-10-15

    In the vitamin K cycle, vitamin K-hydroquinone, the active cofactor for gamma-glutamylcarboxylase, is continuously regenerated. The successive pathways contain oxidation of the hydroquinone to the epoxide, followed by reduction to the quinone and reduction to the hydroquinone. Vitamin K-hydroquinone is a potent radical scavenging species (Mukai et al., J Biol Chem 267: 22277-22281, 1992). We tested the potential antioxidant activity of the vitamin K cycle in lipid peroxidation reactions (thiobarbituric acid reactive substances, TBARS) in rat liver microsomes. As prooxidant we used Fe2+/ascorbate, NADPH-Fe3+/ATP, and NADPH/CCl4. Vitamin K (< or = 50 microM) on its own did not influence the formation of TBARS. In combination with 1 mM dithiothreitol (DTT), the reductive cofactor for the microsomal enzyme vitamin K epoxide reductase, vitamin K suppressed lipid peroxidation with a concentration that blocked the maximal response by 50% (IC50) of ca. 0.2 microM. Vitamin K1 (phylloquinone) and vitamin K2 (menaquinone-4) were equally active. Warfarin (5 microM) and chloro-vitamin K (50 microM), inhibitors of vitamin K epoxide reductase and gamma-glutamylcarboxylase, respectively, were able to completely abolish the antioxidant effect. Lipid peroxidation was inversely related to the amount of vitamin K hydroquinone in the reaction. Vitamin K epoxide reductase seemed sensitive to lipid peroxidation, with half of the activity being lost within 10 min during oxidation with NADPH/CCl4. The inactivation could be attenuated by antioxidants such as vitamin E, reduced glutathione, and menadione and also by a K vitamin in combination with DTT, but not by superoxide dismutase and catalase. The results show that the vitamin K cycle could act as a potent antioxidant, that the active species in all probability is vitamin K-hydroquinone, and that the primary reaction product is the semiquinone. The results also show that the reaction product is processed in the vitamin K cycle to

  17. Attraction and activation of dendritic cells at the site of tumor elicits potent antitumor immunity.

    PubMed

    Lapteva, Natalia; Aldrich, Melissa; Rollins, Lisa; Ren, Wenhong; Goltsova, Tatiana; Chen, Si-Yi; Huang, Xue F

    2009-09-01

    Tumor cells harbor unique genetic mutations, which lead to the generation of immunologically foreign antigenic peptide repertoire with the potential to induce individual tumor-specific immune responses. Here, we developed an in situ tumor vaccine with the ability to elicit antitumor immunity. This vaccine comprised an E1B-deleted oncolytic adenovirus expressing beta-defensin-2 (Ad-BD2-E1A) for releasing tumor antigens, recruiting and activating plasmacytoid dendritic cells (pDCs). Intratumoral injections of Ad-BD2-E1A vaccine inhibited primary breast tumor growth and blocked naturally occurring metastasis in mice. Ad-BD2-E1A vaccination induced potent tumor-specific T-cell responses. Splenic and intratumoral DCs isolated from Ad-BD2-E1A-immunized mice were able to stimulate or promote the differentiation of naive T cells into tumor-specific cytotoxic T cells. We further found that the increased numbers of mature CD45RA(+)CD8alpha(+)CD40(+) pDCs infiltrated into Ad-BD2-E1A-treated tumors. The antitumor effect of Ad-BD2-E1A vaccination was abrogated in toll-like receptor 4 (TLR4) deficient mice, suggesting the critical role of TLR4 in the induction of antitumor immunity by Ad-BD2-E1A. The results of this study indicate that in situ vaccination with the oncolytic BD2-expressing adenovirus preferentially attracts pDCs and promotes their maturation, and thus elicits potent tumor-specific immunity. This vaccine represents an attractive therapeutic strategy for the induction of individualized antitumor immunity.

  18. A Potent, Selective and Cell-active Inhibitor of Human Type I Protein Arginine Methyltransferases

    PubMed Central

    Wu, Hong; Senisterra, Guillermo; Li, Fengling; Butler, Kyle V.; Kaniskan, H. Ümit; Speed, Brandon A.; dela Seña, Carlo; Dong, Aiping; Zeng, Hong; Schapira, Matthieu; Brown, Peter J.; Arrowsmith, Cheryl H.; Barsyte-Lovejoy, Dalia; Liu, Jing; Vedadi, Masoud; Jin, Jian

    2015-01-01

    Protein arginine methyltransferases (PRMTs) play a crucial role in a variety of biological processes. Overexpression of PRMTs has been implicated in various human diseases including cancer. Consequently, selective small-molecule inhibitors of PRMTs have been pursued by both academia and pharmaceutical industry as chemical tools for testing biological and therapeutic hypotheses. PRMTs are divided into three categories: type I PRMTs which catalyze mono- and asymmetric dimethylation of arginine residues, type II PRMTs which catalyze mono- and symmetric dimethylation of arginine residues, and type III PRMT which catalyzes only monomethylation of arginine residues. Here, we report the discovery of a potent, selective and cell-active inhibitor of human type I PRMTs, MS023, and characterization of this inhibitor in a battery of biochemical, biophysical and cellular assays. MS023 displayed high potency for type I PRMTs including PRMT1, 3, 4, 6 and 8, but was completely inactive against type II and type III PRMTs, protein lysine methyltransferases and DNA methyltransferases. A crystal structure of PRMT6 in complex with MS023 revealed that MS023 binds the substrate binding site. MS023 potently decreased cellular levels of histone arginine asymmetric dimethylation. It also reduced global levels of arginine asymmetric dimethylation and concurrently increased levels of arginine monomethylation and symmetric dimethylation in cells. We also developed MS094, a close analog of MS023, which was inactive in biochemical and cellular assays, as a negative control for chemical biology studies. MS023 and MS094 are useful chemical tools for investigating the role of type I PRMTs in health and disease. PMID:26598975

  19. Anticancer copper(II) phosphorus dendrimers are potent proapoptotic Bax activators.

    PubMed

    Mignani, Serge; El Brahmi, Nabil; Eloy, Laure; Poupon, Joel; Nicolas, Valérie; Steinmetz, Anke; El Kazzouli, Said; Bousmina, Mosto M; Blanchard-Desce, Mireille; Caminade, Anne-Marie; Majoral, Jean-Pierre; Cresteil, Thierry

    2017-03-21

    A multivalent phosphorus dendrimer 1G3 and its corresponding Cu-complex, 1G3-Cu have been recently identified as agents retaining high antiproliferative potency. This antiproliferative capacity was preserved in cell lines overexpressing the efflux pump ABC B1, whereas cross-resistance was observed in ovarian cancer cell lines resistant to cisplatin. Theoretical 3D models were constructed: the dendrimers appear as irregularly shaped disk-like nano-objects of about 22 Å thickness and 49 Å diameter, which accumulated in cells after penetration by endocytosis. To get insight in their mode of action, cell death pathways have been examined in human cancer cell lines: early apoptosis was followed by secondary necrosis after multivalent phosphorus dendrimers exposure. The multivalent plain phosphorus dendrimer 1G3 moderately activated caspase-3 activity, in contrast with the multivalent Cu-conjugated phosphorus dendrimer 1G3-Cu which strikingly reduced the caspase-3 content and activity. This decrease of caspase activity is not related to the presence of copper, since inorganic copper has no or little effect on caspase-3. Conversely the potent apoptosis activation could be related to a noticeable translocation of Bax to the mitochondria, resulting in the release of AIF into the cytosol, its translocation to the nucleus and a severe DNA fragmentation, without alteration of the cell cycle. The multivalent Cu-conjugated phosphorus dendrimer is more efficient than its non-complexed analog to activate this pathway in close relationship with the higher antiproliferative potency. Therefore, this multivalent Cu-conjugated phosphorus dendrimer 1G3-Cu can be considered as a new and promising first-in-class antiproliferative agent with a distinctive mode of action, inducing apoptosis tumor cell death through Bax activation pathway.

  20. Potent NLRP3 Inflammasome Activation by the HIV Reverse Transcriptase Inhibitor Abacavir.

    PubMed

    Toksoy, Atiye; Sennefelder, Helga; Adam, Christian; Hofmann, Sonja; Trautmann, Axel; Goebeler, Matthias; Schmidt, Marc

    2017-02-17

    There is experimental and clinical evidence that some exanthematous allergic drug hypersensitivity reactions are mediated by drug-specific T cells. We hypothesized that the capacity of certain drugs to directly stimulate the innate immune system may contribute to generate drug-specific T cells. Here we analyzed whether abacavir, an HIV-1 reverse transcriptase inhibitor often inducing severe delayed-type drug hypersensitivity, can trigger innate immune activation that may contribute to its allergic potential. We show that abacavir fails to generate direct innate immune activation in human monocytes but potently triggers IL-1β release upon pro-inflammatory priming with phorbol ester or Toll-like receptor stimulation. IL-1β processing and secretion were sensitive to Caspase-1 inhibition, NLRP3 knockdown, and K(+) efflux inhibition and were not observed with other non-allergenic nucleoside reverse transcriptase inhibitors, identifying abacavir as a specific inflammasome activator. It further correlated with dose-dependent mitochondrial reactive oxygen species production and cytotoxicity, indicating that inflammasome activation resulted from mitochondrial damage. However, both NLRP3 depletion and inhibition of K(+) efflux mitigated abacavir-induced mitochondrial reactive oxygen species production and cytotoxicity, suggesting that these processes were secondary to NLRP3 activation. Instead, depletion of cardiolipin synthase 1 abolished abacavir-induced IL-1β secretion, suggesting that mitochondrial cardiolipin release may trigger abacavir-induced inflammasome activation. Our data identify abacavir as a novel inflammasome-stimulating drug allergen. They implicate a potential contribution of innate immune activation to medication-induced delayed-type hypersensitivity, which may stimulate new concepts for treatment and prevention of drug allergies.

  1. 3-Amido-3-aryl-piperidines: A Novel Class of Potent, Selective, and Orally Active GlyT1 Inhibitors.

    PubMed

    Pinard, Emmanuel; Alberati, Daniela; Alvarez-Sanchez, Ruben; Brom, Virginie; Burner, Serge; Fischer, Holger; Hauser, Nicole; Kolczewski, Sabine; Lengyel, Judith; Mory, Roland; Saladin, Christian; Schulz-Gasch, Tanja; Stalder, Henri

    2014-04-10

    3-Amido-3-aryl-piperidines were discovered as a novel structural class of GlyT1 inhibitors. The structure-activity relationship, which was developed, led to the identification of highly potent compounds exhibiting excellent selectivity against the GlyT2 isoform, drug-like properties, and in vivo activity after oral administration.

  2. 3-Amido-3-aryl-piperidines: A Novel Class of Potent, Selective, and Orally Active GlyT1 Inhibitors

    PubMed Central

    2014-01-01

    3-Amido-3-aryl-piperidines were discovered as a novel structural class of GlyT1 inhibitors. The structure–activity relationship, which was developed, led to the identification of highly potent compounds exhibiting excellent selectivity against the GlyT2 isoform, drug-like properties, and in vivo activity after oral administration. PMID:24900853

  3. Design and synthesis of 4-substituted quinazolines as potent EGFR inhibitors with anti-breast cancer activity.

    PubMed

    Ahmed, Marwa; Magdy, Naja

    2016-09-23

    Cancer is a major health problem to human beings around the world. Many quinazoline derivatives were reported to have potent cytotoxic activity. Our aim in this work is the discovery of potent epidermal growth factor receptor (EGFR) inhibitors with anti-breast cancer activity containing 4-substituted quinazoline pharmacophore. Novel series of 4-substituted 6,8-dibromo-2-(4-chlorophenyl)-quinazoline derivatives have been designed and synthesized. New derivatives were tested against MCF-7 (human breast carcinoma cell line) and screened for their inhibition activity against epidermal growth factor receptor tyrosine kinase (EGFR-TK). Most of the tested compounds show potent antiproliferative activity and EGFR-TK inhibitory activity. Compounds VIIIc and VIIIb exerted powerful cytotoxic activity (IC50 3.1 and 6.3 µM) with potent inhibitory percent (91.1 and 88.4%) against EGFR-TK. Compounds IX, VIIa, X, VIIb, VIc, V, IV, VIa and VIb showed promising cytotoxic effects with IC50 range (12-79 µM) with good activity against EGFR-TK with the inhibitory percent (85.4-60.8%). On the other hand, compounds VIIc, VIIIa exerted low cytotoxic effects as revealed from their IC50 value (124 and 144 µM) with low activity against EGFR-TK with inhibitory percent 30.6 and 29.1% respectively.

  4. Lanthanide labeling of a potent protease activated receptor-2 agonist for time-resolved fluorescence analysis

    PubMed Central

    Hoffman, Justin; Flynn, Andrea N.; Tillu, Dipti V.; Zhang, Zhenyu; Patek, Renata; Price, Theodore J.; Vagner, Josef; Boitano, Scott

    2012-01-01

    Protease activated receptor-2 (PAR2) is one of four G-protein coupled receptors (GPCRs) that can be activated by exogenous or endogenous proteases, which cleave the extracellular amino-terminus to expose a tethered ligand and subsequent G-protein signaling. Alternatively, PAR2 can be activated by peptide or peptidomimetic ligands derived from the sequence of the natural tethered ligand. Screening of novel ligands that directly bind to PAR2 to agonize or antagonize the receptor has been hindered by the lack of a sensitive, high-throughput, affinity binding assay. In this report we describe the synthesis and use of a modified PAR2 peptidomimetic agonist, 2-furoyl-LIGRLO-(diethylenetriaminepentaacetic acid)-NH2 (2-f-LIGRLO-dtpa), designed for lanthanide-based time resolved fluorescence screening. We first demonstrate that 2-f-LIGRLO-dtpa is a potent and specific PAR2 agonist across a full spectrum of in vitro assays. We then show that 2-f-LIGRLO-dtpa can be utilized in an affinity binding assay to evaluate the ligand-receptor interactions between known high potency peptidomimetic agonists (2-furoyl-LIGRLO-NH2, 2-f-LIGRLO; 2-aminothiazol-4-yl-LIGRL-NH2, 2-at-LIGRL and; 6-aminonicotinyl-LIGRL-NH2, 6-an-LIGRL) and PAR2. A separate N-terminal peptidomimetic modification (3-indoleacetyl-LIGRL-NH2, 3-ia-LIGRL) that does not activate PAR2 signaling was used as a negative control. All three peptidomimetic agonists demonstrated sigmoidal competitive binding curves, with the more potent agonists (2-f-LIGRLO and 2-at-LIGRL) displaying increased competition. In contrast, the control peptide (3-ia-LIGRL) displayed limited competition for PAR2 binding. In summary, we have developed a Europium-containing PAR2 agonist that can be used in a highly sensitive affinity binding assay to screen novel PAR2 ligands in a high-throughput format. This ligand can serve as a critical tool in the screening and development of PAR2 ligands. PMID:22994402

  5. Nifuroxazide exerts potent anti-tumor and anti-metastasis activity in melanoma.

    PubMed

    Zhu, Yongxia; Ye, Tinghong; Yu, Xi; Lei, Qian; Yang, Fangfang; Xia, Yong; Song, Xuejiao; Liu, Li; Deng, Hongxia; Gao, Tiantao; Peng, Cuiting; Zuo, Weiqiong; Xiong, Ying; Zhang, Lidan; Wang, Ningyu; Zhao, Lifeng; Xie, Yongmei; Yu, Luoting; Wei, Yuquan

    2016-02-02

    Melanoma is a highly malignant neoplasm of melanocytes with considerable metastatic potential and drug resistance, explaining the need for new candidates that inhibit tumor growth and metastasis. The signal transducer and activator of the transcription 3 (Stat3) signaling pathway plays an important role in melanoma and has been validated as promising anticancer target for melanoma therapy. In this study, nifuroxazide, an antidiarrheal agent identified as an inhibitor of Stat3, was evaluated for its anti-melanoma activity in vitro and in vivo. It had potent anti-proliferative activity against various melanoma cell lines and could induce G2/M phase arrest and cell apoptosis. Moreover, nifuroxazide markedly impaired melanoma cell migration and invasion by down-regulating phosphorylated-Src, phosphorylated-FAK, and expression of matrix metalloproteinase (MMP) -2, MMP-9 and vimentin. It also significantly inhibited tumor growth without obvious side effects in the A375-bearing mice model by inducing apoptosis and reducing cell proliferation and metastasis. Notably, nifuroxazide significantly inhibited pulmonary metastases, which might be associated with the decrease of myeloid-derived suppressor cells (MDSCs). These findings suggested that nifuroxazide might be a potential agent for inhibiting the growth and metastasis of melanoma.

  6. Nifuroxazide exerts potent anti-tumor and anti-metastasis activity in melanoma

    PubMed Central

    Zhu, Yongxia; Ye, Tinghong; Yu, Xi; Lei, Qian; Yang, Fangfang; Xia, Yong; Song, Xuejiao; Liu, Li; Deng, Hongxia; Gao, Tiantao; Peng, Cuiting; Zuo, Weiqiong; Xiong, Ying; Zhang, Lidan; Wang, Ningyu; Zhao, Lifeng; Xie, Yongmei; Yu, Luoting; Wei, Yuquan

    2016-01-01

    Melanoma is a highly malignant neoplasm of melanocytes with considerable metastatic potential and drug resistance, explaining the need for new candidates that inhibit tumor growth and metastasis. The signal transducer and activator of the transcription 3 (Stat3) signaling pathway plays an important role in melanoma and has been validated as promising anticancer target for melanoma therapy. In this study, nifuroxazide, an antidiarrheal agent identified as an inhibitor of Stat3, was evaluated for its anti-melanoma activity in vitro and in vivo. It had potent anti-proliferative activity against various melanoma cell lines and could induce G2/M phase arrest and cell apoptosis. Moreover, nifuroxazide markedly impaired melanoma cell migration and invasion by down-regulating phosphorylated-Src, phosphorylated-FAK, and expression of matrix metalloproteinase (MMP) -2, MMP-9 and vimentin. It also significantly inhibited tumor growth without obvious side effects in the A375-bearing mice model by inducing apoptosis and reducing cell proliferation and metastasis. Notably, nifuroxazide significantly inhibited pulmonary metastases, which might be associated with the decrease of myeloid-derived suppressor cells (MDSCs). These findings suggested that nifuroxazide might be a potential agent for inhibiting the growth and metastasis of melanoma. PMID:26830149

  7. Secretory phospholipase A2 modified HDL rapidly and potently suppresses platelet activation.

    PubMed

    Curcic, Sanja; Holzer, Michael; Pasterk, Lisa; Knuplez, Eva; Eichmann, Thomas O; Frank, Saša; Zimmermann, Robert; Schicho, Rudolf; Heinemann, Akos; Marsche, Gunther

    2017-08-14

    Levels of secretory phospholipases A2 (sPLA2) highly increase under acute and chronic inflammatory conditions. sPLA2 is mainly associated with high-density lipoproteins (HDL) and generates bioactive lysophospholipids implicated in acute and chronic inflammatory processes. Unexpectedly, pharmacological inhibition of sPLA2 in patients with acute coronary syndrome was associated with an increased risk of myocardial infarction and stroke. Given that platelets are key players in thrombosis and inflammation, we hypothesized that sPLA2-induced hydrolysis of HDL-associated phospholipids (sPLA2-HDL) generates modified HDL particles that affect platelet function. We observed that sPLA2-HDL potently and rapidly inhibited platelet aggregation induced by several agonists, P-selectin expression, GPIIb/IIIa activation and superoxide production, whereas native HDL showed little effects. sPLA2-HDL suppressed the agonist-induced rise of intracellular Ca(2+) levels and phosphorylation of Akt and ERK1/2, which trigger key steps in promoting platelet activation. Importantly, sPLA2 in the absence of HDL showed no effects, whereas enrichment of HDL with lysophosphatidylcholines containing saturated fatty acids (the main sPLA2 products) mimicked sPLA2-HDL activities. Our findings suggest that sPLA2 generates lysophosphatidylcholine-enriched HDL particles that modulate platelet function under inflammatory conditions.

  8. Caged Garcinia Xanthones, a Novel Chemical Scaffold with Potent Antimalarial Activity.

    PubMed

    Ke, Hangjun; Morrisey, Joanne M; Qu, Shiwei; Chantarasriwong, Oraphin; Mather, Michael W; Theodorakis, Emmanuel A; Vaidya, Akhil B

    2017-01-01

    Caged Garcinia xanthones (CGXs) constitute a family of natural products that are produced by tropical/subtropical trees of the genus Garcinia CGXs have a unique chemical architecture, defined by the presence of a caged scaffold at the C ring of a xanthone moiety, and exhibit a broad range of biological activities. Here we show that synthetic CGXs exhibit antimalarial activity against Plasmodium falciparum, the causative parasite of human malaria, at the intraerythrocytic stages. Their activity can be substantially improved by attaching a triphenylphosphonium group at the A ring of the caged xanthone. Specifically, CR135 and CR142 were found to be highly effective antimalarial inhibitors, with 50% effective concentrations as low as ∼10 nM. CGXs affect malaria parasites at multiple intraerythrocytic stages, with mature stages (trophozoites and schizonts) being more vulnerable than immature rings. Within hours of CGX treatment, malaria parasites display distinct morphological changes, significant reduction of parasitemia (the percentage of infected red blood cells), and aberrant mitochondrial fragmentation. CGXs do not, however, target the mitochondrial electron transport chain, the target of the drug atovaquone and several preclinical candidates. CGXs are cytotoxic to human HEK293 cells at the low micromolar level, which results in a therapeutic window of around 150-fold for the lead compounds. In summary, we show that CGXs are potent antimalarial compounds with structures distinct from those of previously reported antimalarial inhibitors. Our results highlight the potential to further develop Garcinia natural product derivatives as novel antimalarial agents. Copyright © 2016 American Society for Microbiology.

  9. A potent synthetic inorganic antibiotic with activity against drug-resistant pathogens

    PubMed Central

    Hubick, Shelby; Jayaraman, Arumugam; McKeen, Alexander; Reid, Shelby; Alcorn, Jane; Stavrinides, John; Sterenberg, Brian T.

    2017-01-01

    The acronymously named “ESKAPE” pathogens represent a group of bacteria that continue to pose a serious threat to human health, not only due to their propensity for repeated emergence, but also due to their ability to “eskape” antibiotic treatment12. The evolution of multi-drug resistance in these pathogens alone has greatly outpaced the development of new therapeutics, necessitating an alternative strategy for antibiotic development that considers the evolutionary mechanisms driving antibiotic resistance. In this study, we synthesize a novel inorganic antibiotic, phosphopyricin, which has antibiotic activity against the Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE). We show that this potent antibiotic is bactericidal, and exhibits low toxicity in an acute dose assay in mice. As a synthetic compound that does not occur naturally, phosphopyricin would be evolutionarily foreign to microbes, thereby slowing the evolution of resistance. In addition, it loses antibiotic activity upon exposure to light, meaning that the active antibiotic will not accumulate in the general environment where strong selective pressures imposed by antibiotic residuals are known to accelerate resistance. Phosphopyricin represents an innovation in antimicrobials, having a synthetic core, and a photosensitive chemical architecture that would reduce accumulation in the environment. PMID:28165020

  10. A potent synthetic inorganic antibiotic with activity against drug-resistant pathogens.

    PubMed

    Hubick, Shelby; Jayaraman, Arumugam; McKeen, Alexander; Reid, Shelby; Alcorn, Jane; Stavrinides, John; Sterenberg, Brian T

    2017-02-06

    The acronymously named "ESKAPE" pathogens represent a group of bacteria that continue to pose a serious threat to human health, not only due to their propensity for repeated emergence, but also due to their ability to "eskape" antibiotic treatment. The evolution of multi-drug resistance in these pathogens alone has greatly outpaced the development of new therapeutics, necessitating an alternative strategy for antibiotic development that considers the evolutionary mechanisms driving antibiotic resistance. In this study, we synthesize a novel inorganic antibiotic, phosphopyricin, which has antibiotic activity against the Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE). We show that this potent antibiotic is bactericidal, and exhibits low toxicity in an acute dose assay in mice. As a synthetic compound that does not occur naturally, phosphopyricin would be evolutionarily foreign to microbes, thereby slowing the evolution of resistance. In addition, it loses antibiotic activity upon exposure to light, meaning that the active antibiotic will not accumulate in the general environment where strong selective pressures imposed by antibiotic residuals are known to accelerate resistance. Phosphopyricin represents an innovation in antimicrobials, having a synthetic core, and a photosensitive chemical architecture that would reduce accumulation in the environment.

  11. Potent nematicidal activity of phthalaldehyde, salicylaldehyde, and cinnamic aldehyde against Meloidogyne incognita.

    PubMed

    Caboni, Pierluigi; Aissani, Nadhem; Cabras, Tiziana; Falqui, Andrea; Marotta, Roberto; Liori, Barbara; Ntalli, Nikoletta; Sarais, Giorgia; Sasanelli, Nicola; Tocco, Graziella

    2013-02-27

    The nematicidal activity of selected aromatic aldehydes was tested against the root knot nematode Meloidogyne incognita. The most active aldehyde was phthalaldehyde (1) with an EC(50) value of 11 ± 6 mg/L followed by salicylaldehyde (2) and cinnamic aldehyde (3) with EC(50) values of 11 ± 1 and 12 ± 5 mg/L, respectively. On the other hand, structurally related aldehydes such as 2-methoxybenzaldehyde (21), 3,4-dimethoxybenzaldehyde, and vanillin (23) were not active at the concentration of 1000 mg/L. By liquid chromatography-mass spectrometry the reactivity of tested aldehydes against a synthetic peptide resembling the nematode cuticle was characterized. At the test concentration of 1 mM, the main adduct formation was observed for 3,4-dihydroxybenzaldehyde (22), 2-methoxybenzaldehyde (21), and 3,4-dimethoxybenzaldehyde. Considering that 2-methoxybenzaldehyde (21) and 3,4-dimethoxybenzaldehyde were not active against M. incognita in in vitro experiments led us to hypothesize a different mechanism of action rather than an effect on the external cuticle modification of nematodes. When the toxicity of the V-ATPase inhibitor pyocyanin (10) was tested against M. incognita J2 nematodes, an EC(50) at 24 h of 72 ± 25 mg/L was found. The redox-active compounds such as phthalaldehyde (1) and salicylaldehyde (2) may share a common mode of action inhibiting nematode V-ATPase enzyme. The results of this investigation reveal that aromatic redox-active aldehydes can be considered as potent nematicides, and further investigation is needed to completely clarify their mode of action.

  12. Taurine is a potent activator of extrasynaptic GABA(A) receptors in the thalamus.

    PubMed

    Jia, Fan; Yue, Minerva; Chandra, Dev; Keramidas, Angelo; Goldstein, Peter A; Homanics, Gregg E; Harrison, Neil L

    2008-01-02

    Taurine is one of the most abundant free amino acids in the brain. In a number of studies, taurine has been reported to activate glycine receptors (Gly-Rs) at moderate concentrations (> or = 100 microM), and to be a weak agonist at GABA(A) receptors (GABA(A)-Rs), which are usually activated at high concentrations (> or = 1 mM). In this study, we show that taurine reduced the excitability of thalamocortical relay neurons and activated both extrasynaptic GABA(A)-Rs and Gly-Rs in neurons in the mouse ventrobasal (VB) thalamus. Low concentrations of taurine (10-100 microM) decreased neuronal input resistance and firing frequency, and elicited a steady outward current under voltage clamp, but had no effects on fast inhibitory synaptic currents. Currents elicited by 50 microM taurine were abolished by gabazine, insensitive to midazolam, and partially blocked by 20 microM Zn2+, consistent with the pharmacological properties of extrasynaptic GABA(A)-Rs (alpha4beta2delta subtype) involved in tonic inhibition in the thalamus. Tonic inhibition was enhanced by an inhibitor of taurine transport, suggesting that taurine can act as an endogenous activator of these receptors. Taurine-evoked currents were absent in relay neurons from GABA(A)-R alpha4 subunit knock-out mice. The amplitude of the taurine current was larger in neurons from adult mice than juvenile mice. Taurine was a more potent agonist at recombinant alpha4beta2delta GABA(A)-Rs than at alpha1beta2gamma2 GABA(A)-Rs. We conclude that physiological concentrations of taurine can inhibit VB neurons via activation of extrasynaptic GABA(A)-Rs and that taurine may function as an endogenous regulator of excitability and network activity in the thalamus.

  13. Collybolide is a novel biased agonist of κ-opioid receptors with potent antipruritic activity

    PubMed Central

    Gupta, Achla; Gomes, Ivone; Bobeck, Erin N.; Fakira, Amanda K.; Massaro, Nicholas P.; Sharma, Indrajeet; Cavé, Adrien; Hamm, Heidi E.; Parello, Joseph

    2016-01-01

    Among the opioid receptors, the κ-opioid receptor (κOR) has been gaining considerable attention as a potential therapeutic target for the treatment of complex CNS disorders including depression, visceral pain, and cocaine addiction. With an interest in discovering novel ligands targeting κOR, we searched natural products for unusual scaffolds and identified collybolide (Colly), a nonnitrogenous sesquiterpene from the mushroom Collybia maculata. This compound has a furyl-δ-lactone core similar to that of Salvinorin A (Sal A), another natural product from the plant Salvia divinorum. Characterization of the molecular pharmacological properties reveals that Colly, like Sal A, is a highly potent and selective κOR agonist. However, the two compounds differ in certain signaling and behavioral properties. Colly exhibits 10- to 50-fold higher potency in activating the mitogen-activated protein kinase pathway compared with Sal A. Taken with the fact that the two compounds are equipotent for inhibiting adenylyl cyclase activity, these results suggest that Colly behaves as a biased agonist of κOR. Behavioral studies also support the biased agonistic activity of Colly in that it exhibits ∼10-fold higher potency in blocking non–histamine-mediated itch compared with Sal A, and this difference is not seen in pain attenuation by these two compounds. These results represent a rare example of functional selectivity by two natural products that act on the same receptor. The biased agonistic activity, along with an easily modifiable structure compared with Sal A, makes Colly an ideal candidate for the development of novel therapeutics targeting κOR with reduced side effects. PMID:27162327

  14. Direct regulation of androgen receptor activity by potent CYP17 inhibitors in prostate cancer cells.

    PubMed

    Soifer, Harris S; Souleimanian, Naira; Wu, Sijian; Voskresenskiy, Anatoliy M; Collak, Filiz Kisaayak; Cinar, Bekir; Stein, Cy A

    2012-02-03

    TOK-001 and abiraterone are potent 17-heteroarylsteroid (17-HAS) inhibitors of Cyp17, one of the rate-limiting enzymes in the biosynthesis of testosterone from cholesterol in prostate cancer cells. Nevertheless, the molecular mechanism underlying the prevention of prostate cell growth by 17-HASs still remains elusive. Here, we assess the effects of 17-HASs on androgen receptor (AR) activity in LNCaP and LAPC-4 cells. We demonstrate that both TOK-001 and abiraterone reduced AR protein and mRNA expression, and antagonized AR-dependent promoter activation induced by androgen. TOK-001, but not abiraterone, is an effective apparent competitor of the radioligand [(3)H]R1881 for binding to the wild type and various mutant AR (W741C, W741L) proteins. In agreement with these data, TOK-001 is a consistently superior inhibitor than abiraterone of R1881-induced transcriptional activity of both wild type and mutant AR. However, neither agent was able to trans-activate the AR in the absence of R1881. Our data demonstrate that phospho-4EBP1 levels are significantly reduced by TOK-001 and to a lesser extent by abiraterone alcohol, and suggest a mechanism by which cap-dependent translation is suppressed by blocking assembly of the eIF4F and eIF4G complex to the mRNA 5' cap. Thus, the effects of these 17-HASs on AR signaling are complex, ranging from a decrease in testosterone production through the inhibition of Cyp17 as previously described, to directly reducing both AR protein expression and R1881-induced AR trans-activation.

  15. Potent inhibition of human neutrophil activations by bractelactone, a novel chalcone from Fissistigma bracteolatum

    SciTech Connect

    Wu, Yang-Chang; Sureshbabu, Munisamy; Fang, Yao-Ching; Wu, Yi-Hsiu; Lan, Yu-Hsuan; Chang, Fang-Rong; Chang, Ya-Wen; Hwang, Tsong-Long

    2013-02-01

    Fissistigma bracteolatum is widely used in traditional medicine to treat inflammatory diseases. However, its active components and mechanisms of action remain unclear. In this study, (3Z)-6,7-dihydroxy-4-methoxy-3-(phenylmethylidene)-5-(3-phenylpropanoyl) -1-benzofuran-2(3H) (bractelactone), a novel chalcone from F. bracteolatum, showed potent inhibitory effects against superoxide anion (O{sub 2}{sup ·−}) production, elastase release, and CD11b expression in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-induced human neutrophils. However, bractelactone showed only weak inhibition of phorbol myristate acetate-caused O{sub 2}{sup ·−} production. The peak cytosolic calcium concentration ([Ca{sup 2+}]{sub i}) was unaltered by bractelactone in FMLP-induced neutrophils, but the decay time of [Ca{sup 2+}]{sub i} was significantly shortened. In a calcium-free solution, changes in [Ca{sup 2+}]{sub i} caused by the addition of extracellular Ca{sup 2+} were inhibited by bractelactone in FMLP-activated cells. In addition, bractelactone did not alter the phosphorylation of p38 MAPK, ERK, JNK, or AKT or the concentration of cAMP. These results suggest that bractelactone selectively inhibits store-operated calcium entry (SOCE). In agreement with this concept, bractelactone suppressed sustained [Ca{sup 2+}]{sub i} changes in thapsigargin-activated neutrophils. Furthermore, bractelactone did not alter FMLP-induced formation of inositol 1,4,5-triphosphate. Taken together, our results demonstrate that the anti-inflammatory effects of bractelactone, an active ingredient of F. bracteolatum, in human neutrophils are through the selective inhibition of SOCE. Highlights: ► Bractelactone isolated from Fissistigma bracteolatum. ► Bractelactone inhibited FMLP-induced human neutrophil activations. ► Bractelactone had no effect on IP3 formation. ► Bractelactone did not alter MAPKs, AKT, and cAMP pathways. ► Bractelactone inhibited store-operated calcium entry.

  16. Regenerating bone marrow produces a potent growth-promoting activity to osteogenic cells.

    PubMed

    Bab, I; Gazit, D; Muhlrad, A; Shteyer, A

    1988-07-01

    It is well documented that injury to bone marrow is followed by an osteogenic phase that precedes the complete tissue regeneration. We have recently shown that postablation healing of bone marrow in rat tibiae is associated with a systemic increase in osteogenesis. It was hypothesized that a growth factor(s) with an effect on osteogenic cells is produced in the healing limb, is transferred to the blood circulation, and enhances osteogenesis systemically. To test growth factor production, healing bone marrow-conditioned medium was prepared with tissue separated from rat tibias during the osteogenic phase and assayed for enhancement of mitogenic activity in culture of osteogenic rat osteosarcoma cells (ROS 17/2). Partial purification of healing bone marrow-conditioned medium-derived growth factor(s) consisted of gel filtration on Sephadex G-25, boiling, chromatography on heparin-Sepharose, and gel filtration on Sephadex G-75. Mitogenic activity eluted in the void volume of the Sephadex G-25 column (mol wt greater than 5,000). Potent activity resolved from heparin-Sepharose with PBS, and on filtration by Sephadex G-75 this activity recovered in 3 peaks with mol wt estimates of 35,000, 19,000, and less than 10,000. The partially purified factor also showed considerable stimulatory effect on DNA synthesis in osteoblastic fetal rat calvarial cells and on in vitro elongation of fetal long bone; it had only a small effect on nonosteoblastic ROS and fetal rat calvarial cells. These data indicate that healing bone marrow produces growth factor activity with a preferential effect on osteogenic cells. It is suggested that local growth factors have a role as mediators in the sequence of events whereby bone marrow expresses its osteogenic potential. During postablation healing of bone marrow these factors may also function as systemic promoters to osteogenic cells.

  17. Characterization of DicB by partially masking its potent inhibitory activity of cell division

    PubMed Central

    Yang, Shaoyuan; Pei, Hairun; Zhang, Xiaoying; Wei, Qiang; Zhu, Jia; Zheng, Jimin; Jia, Zongchao

    2016-01-01

    DicB, a protein encoded by the Kim (Qin) prophage in Escherichia coli, inhibits cell division through interaction with MinC. Thus far, characterization of DicB has been severely hampered owing to its potent activity which ceases cell division and leads to cell death. In this work, through fusing maltose-binding protein to the N-terminus of DicB (MBP–DicB), we successfully expressed and purified recombinant DicB that enabled in vitro analysis for the first time. More importantly, taking advantage of the reduced inhibitory activity of MBP–DicB, we were able to study its effects on cell growth and morphology. Inhibition of cell growth by MBP–DicB was systematically evaluated using various DicB constructs, and their corresponding effects on cell morphology were also investigated. Our results revealed that the N-terminal segment of DicB plays an essential functional role, in contrast to its C-terminal tail. The N-terminus of DicB is of critical importance as even the first amino acid (following the initial Met) could not be removed, although it could be mutated. This study provides the first glimpse of the molecular determinants underlying DicB's function. PMID:27466443

  18. Biotin analogues with antibacterial activity are potent inhibitors of biotin protein ligase.

    PubMed

    Soares da Costa, Tatiana P; Tieu, William; Yap, Min Y; Zvarec, Ondrej; Bell, Jan M; Turnidge, John D; Wallace, John C; Booker, Grant W; Wilce, Matthew C J; Abell, Andrew D; Polyak, Steven W

    2012-06-14

    There is a desperate need to develop new antibiotic agents to combat the rise of drug-resistant bacteria, such as clinically important Staphylococcus aureus. The essential multifunctional enzyme, biotin protein ligase (BPL), is one potential drug target for new antibiotics. We report the synthesis and characterization of a series of biotin analogues with activity against BPLs from S. aureus, Escherichia coli, and Homo sapiens. Two potent inhibitors with K i < 100 nM were identified with antibacterial activity against a panel of clinical isolates of S. aureus (MIC 2-16 μg/mL). Compounds with high ligand efficiency and >20-fold selectivity between the isozymes were identified and characterized. The antibacterial mode of action was shown to be via inhibition of BPL. The bimolecular interactions between the BPL and the inhibitors were defined by surface plasmon resonance studies and X-ray crystallography. These findings pave the way for second-generation inhibitors and antibiotics with greater potency and selectivity.

  19. Putting copper into action: copper-impregnated products with potent biocidal activities.

    PubMed

    Borkow, Gadi; Gabbay, Jeffrey

    2004-11-01

    Copper ions, either alone or in copper complexes, have been used for centuries to disinfect liquids, solids, and human tissue. Today copper is used as a water purifier, algaecide, fungicide, nematocide, molluscicide, and antibacterial and antifouling agent. Copper also displays potent antiviral activity. We hypothesized that introducing copper into clothing, bedding, and other articles would provide them with biocidal properties. A durable platform technology has been developed that introduces copper into cotton fibers, latex, and other polymeric materials. This study demonstrates the broad-spectrum antimicrobial (antibacterial, antiviral, antifungal) and antimite activities of copper-impregnated fibers and polyester products. This technology enabled the production of antiviral gloves and filters (which deactivate HIV-1 and other viruses), antibacterial self-sterilizing fabrics (which kill antibiotic-resistant bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci), antifungal socks (which alleviate symptoms of athlete's foot), and anti-dust mite mattress covers (which reduce mite-related allergies). These products did not have skin-sensitizing properties, as determined by guine pig maximization and rabbit skin irritation tests. Our study demonstrates the potential use of copper in new applications. These applications address medical issues of the greatest importance, such as viral transmissions; nosocomial, or healthcare-associated, infections; and the spread of antibiotic-resistant bacteria.

  20. Design, synthesis, and structure-activity relationship studies of a potent PACE4 inhibitor.

    PubMed

    Kwiatkowska, Anna; Couture, Frédéric; Levesque, Christine; Ly, Kévin; Desjardins, Roxane; Beauchemin, Sophie; Prahl, Adam; Lammek, Bernard; Neugebauer, Witold; Dory, Yves L; Day, Robert

    2014-01-09

    PACE4 plays an important role in the progression of prostate cancer and is an attractive target for the development of novel inhibitor-based tumor therapies. We previously reported the design and synthesis of a novel, potent, and relatively selective PACE4 inhibitor known as a Multi-Leu (ML) peptide. In the present work, we examined the ML peptide through detailed structure-activity relationship studies. A variety of ML-peptide analogues modified at the P8-P5 positions with leucine isomers (Nle, DLeu, and DNle) or substituted at the P1 position with arginine mimetics were tested for their inhibitory activity, specificity, stability, and antiproliferative effect. By incorporating d isomers at the P8 position or a decarboxylated arginine mimetic, we obtained analogues with an improved stability profile and excellent antiproliferative properties. The DLeu or DNle residue also has improved specificity toward PACE4, whereas specificity was reduced for a peptide modified with the arginine mimetic, such as 4-amidinobenzylamide.

  1. Gossypol enantiomers potently inhibit human placental 3β-hydroxysteroid dehydrogenase 1 and aromatase activities.

    PubMed

    Dong, Yaoyao; Mao, Baiping; Li, Linxi; Guan, Hongguo; Su, Ying; Li, Xiaoheng; Lian, Qingquan; Huang, Ping; Ge, Ren-Shan

    2016-03-01

    Gossypol is a chemical isolated from cotton seeds. It exists as (+) or (-) enantiomer and has been tested for anticancer, abortion-inducing, and male contraception. Progesterone formed from pregnenolone by 3β-hydroxysteroid dehydrogenase 1 (HSD3B1) and estradiol from androgen by aromatase (CYP19A1) are critical for the maintenance of pregnancy or associated with some cancers. In this study we compared the potencies of (+)- and (-)-gossypol enantiomers in the inhibition of HSD3B1 and aromatase activities as well as progesterone and estradiol production in human placental JEG-3 cells. (+) Gossypol showed potent inhibition on human placental HSD3B1 with IC50 value of 2.3 μM, while (-) gossypol weakly inhibited it with IC50 over 100 μM. In contrast, (-) gossypol moderately inhibited CYP19A1 activity with IC50 of 23 μM, while (+) gossypol had no inhibition when the highest concentration (100 μM) was tested. (+) Gossypol enantiomer competitively inhibited HSD3B1 against substrate pregnenolone and showed mixed mode against NAD(+). (-) Gossypol competitively inhibited CYP19A1 against substrate testosterone. Gossypol enantiomers showed different potency related to their inhibition on human HSD3B1 and CYP19A1. Whether gossypol enantiomer is used alone or in combination relies on its application and beneficial effects.

  2. IPD-196, a novel phosphatidylinositol 3-kinase inhibitor with potent anticancer activity against hepatocellular carcinoma.

    PubMed

    Lee, Ju-Hee; Lee, Hyunseung; Yun, Sun-Mi; Jung, Kyung Hee; Jeong, Yujeong; Yan, Hong Hua; Hong, Sungwoo; Hong, Soon-Sun

    2013-02-01

    As the activation of phosphatidylinositol 3-kinase (PI3K) is associated with a wide variety of human malignancies, it is emerging as an attractive target for cancer treatment. In this study we synthesized a novel PI3Kα inhibitor, IPD-196 [ethyl 6-(5-(2,4-difluorophenylsulfonamido)pyridin-3-yl)imidazo[1,2-a]pyridine-3-carboxylate], and evaluated its anticancer effects on human hepatocellular carcinoma (HCC) cells. IPD-196 effectively inhibited the phosphorylation of downstream PI3K effectors such as Akt, mTOR, p70S6K, and 4E-BP1, and its antiproliferative effect was more potent than that of sorafenib or LY294002. It also induced cell cycle arrest at the G0/G1 phase as well as apoptosis by increasing the proportion of sub-G1 apoptotic cells, and the levels of cleaved PARP, caspase-3, and caspase-9. Furthermore, it decreased the expression of HIF-1α and VEGF in Huh-7 cells, and inhibited tube formation and migration of human umbilical vein endothelial cells, which was confirmed by a Matrigel plug assay in mice. Taken together, IPD-196 exhibited its anticancer activity through disruption of the PI3K/Akt pathway that caused cell cycle arrest, apoptosis induction, and inhibition of angiogenesis in human HCC cells. We therefore suggest that IPD-196 may be a potential candidate drug for targeted HCC therapy.

  3. Novel, highly potent systemic glucokinase activators for the treatment of Type 2 Diabetes Mellitus.

    PubMed

    Xu, Jiayi; Lin, Songnian; Myers, Robert W; Addona, George; Berger, Joel P; Campbell, Brian; Chen, Hsuan-Shen; Chen, Zhesheng; Eiermann, George J; Elowe, Nadine H; Farrer, Brian T; Feng, Wen; Fu, Qinghong; Kats-Kagan, Roman; Kavana, Michael; Malkani, Sunita; McMasters, Daniel R; Mitra, Kaushik; Pachanski, Michele J; Tong, Xinchun; Trujillo, Maria E; Xu, Libo; Zhang, Bei; Zhang, Fengqi; Zhang, Rui; Parmee, Emma R

    2017-05-01

    Glucokinase (GK, hexokinase IV) is a unique hexokinase that plays a central role in mammalian glucose homeostasis. Glucose phosphorylation by GK in the pancreatic β-cell is the rate-limiting step that controls glucose-stimulated insulin secretion. Similarly, GK-mediated glucose phosphorylation in hepatocytes plays a major role in increasing hepatic glucose uptake and metabolism and possibly lowering hepatic glucose output. Small molecule GK activators (GKAs) have been identified that increase enzyme activity by binding to an allosteric site. GKAs offer a novel approach for the treatment of Type 2 Diabetes Mellitus (T2DM) and as such have garnered much attention. We now report the design, synthesis, and biological evaluation of a novel series of 2,5,6-trisubstituted indole derivatives that act as highly potent GKAs. Among them, Compound 1 was found to possess high in vitro potency, excellent physicochemical properties, and good pharmacokinetic profile in rodents. Oral administration of Compound 1 at doses as low as 0.03mg/kg led to robust blood glucose lowering efficacy in 3week high fat diet-fed mice. Copyright © 2016. Published by Elsevier Ltd.

  4. Identification of a Small Molecular Insulin Receptor Agonist With Potent Antidiabetes Activity

    PubMed Central

    Qiang, Guifen; Xue, Shenghui; Yang, Jenny J.; Du, Guanhua; Pang, Xiaobin; Li, Xiaoting; Goswami, Devrishi; Griffin, Patrick R.; Ortlund, Eric A.; Chan, Chi Bun; Ye, Keqiang

    2014-01-01

    Insulin replacement therapy is a widely adopted treatment for all patients with type 1 diabetes and some with type 2 diabetes. However, injection of insulin has suffered from problems such as tissue irritation, abscesses, discomfort, and inconvenience. The use of orally bioactive insulin mimetics thus represents an ideal treatment alternative. Here we show that a chaetochromin derivative (4548-G05) acts as a new nonpeptidyl insulin mimetic. 4548-G05 selectively activates an insulin receptor (IR) but not insulin-like growth factor receptor-I or other receptor tyrosine kinases. Through binding to the extracellular domain of the IR, 4548-G05 induces activation of the receptor and initiates the downstream Akt and extracellular signal–related kinase pathways to trigger glucose uptake in C2C12 myotubes. Moreover, it displays a potent blood glucose-lowering effect when administrated orally in normal, type 1 diabetic, and type 2 diabetic mice models. Therefore, 4548-G05 may represent a novel pharmacological agent for antidiabetes drug development. PMID:24651808

  5. Polybrominated diphenyl ethers with potent and broad spectrum antimicrobial activity from the marine sponge Dysidea.

    PubMed

    Sun, Shi; Canning, Corene B; Bhargava, Kanika; Sun, Xiuxiu; Zhu, Wenjun; Zhou, Ninghui; Zhang, Yifan; Zhou, Kequan

    2015-01-01

    Three polybrominated diphenyl ethers, 2-(2',4'-dibromophenoxy)-3,5-dibromophenol (1) and 2-(2',4'-dibromophenoxy)-3,4,5-tribromophenol (2) were isolated from the marine sponge Dysidea granulosa; and 2-(2',4'-dibromophenoxy)-4,6-dibromophenol (3) from Dysidea spp. They exhibited potent and broad spectrum in vitro antibacterial activity, especially against methicillin resistant Staphylococcus aureus (MRSA), methicillin sensitive Staphylococcus aureus (MSSA), Escherichia coli O157:H7, and Salmonella. Minimal inhibitory concentration (MIC) was evaluated against 12 clinical and standard strains of Gram positive and negative bacteria. The observed MIC range was 0.1-4.0mg/L against all the Gram positive bacteria and 0.1-16.0mg/L against Gram negative bacteria. 2-(2',4″-Dibromophenoxy)-3,5-dibromophenol showed stronger broad spectrum antibacterial activity than other two compounds. 2-(2',4″-Dibromophenoxy)-3,5-dibromophenol and 2-(2',4'-dibromophenoxy)-4,6-dibromophenol are thermo-stable. The results suggest that 2-(2',4'-dibromophenoxy)-3,5-dibromophenol could be used as a potential lead molecule for anti-MRSA, anti-E. coli O157:H7, and anti-Salmonella for drug development.

  6. Mirror-image organometallic osmium arene iminopyridine halido complexes exhibit similar potent anticancer activity.

    PubMed

    Fu, Ying; Soni, Rina; Romero, María J; Pizarro, Ana M; Salassa, Luca; Clarkson, Guy J; Hearn, Jessica M; Habtemariam, Abraha; Wills, Martin; Sadler, Peter J

    2013-11-04

    Four chiral Os(II) arene anticancer complexes have been isolated by fractional crystallization. The two iodido complexes, (S(Os),S(C))-[Os(η(6)-p-cym)(ImpyMe)I]PF6 (complex 2, (S)-ImpyMe: N-(2-pyridylmethylene)-(S)-1-phenylethylamine) and (R(Os),R(C))-[Os(η(6)-p-cym)(ImpyMe)I]PF6 (complex 4, (R)-ImpyMe: N-(2-pyridylmethylene)-(R)-1-phenylethylamine), showed higher anticancer activity (lower IC50 values) towards A2780 human ovarian cancer cells than cisplatin and were more active than the two chlorido derivatives, (S(Os),S(C))-[Os(η(6)-p-cym)(ImpyMe)Cl]PF6, 1, and (R(Os),R(C))-[Os(η(6)-p-cym)(ImpyMe)Cl]PF6, 3. The two iodido complexes were evaluated in the National Cancer Institute 60-cell-line screen, by using the COMPARE algorithm. This showed that the two potent iodido complexes, 2 (NSC: D-758116/1) and 4 (NSC: D-758118/1), share surprisingly similar cancer cell selectivity patterns with the anti-microtubule drug, vinblastine sulfate. However, no direct effect on tubulin polymerization was found for 2 and 4, an observation that appears to indicate a novel mechanism of action. In addition, complexes 2 and 4 demonstrated potential as transfer-hydrogenation catalysts for imine reduction.

  7. Activation of TRPM3 by a potent synthetic ligand reveals a role in peptide release.

    PubMed

    Held, Katharina; Kichko, Tatjana; De Clercq, Katrien; Klaassen, Hugo; Van Bree, Rieta; Vanherck, Jean-Christophe; Marchand, Arnaud; Reeh, Peter W; Chaltin, Patrick; Voets, Thomas; Vriens, Joris

    2015-03-17

    Transient receptor potential (TRP) cation channel subfamily M member 3 (TRPM3), a member of the TRP channel superfamily, was recently identified as a nociceptor channel in the somatosensory system, where it is involved in the detection of noxious heat; however, owing to the lack of potent and selective agonists, little is known about other potential physiological consequences of the opening of TRPM3. Here we identify and characterize a synthetic TRPM3 activator, CIM0216, whose potency and apparent affinity greatly exceeds that of the canonical TRPM3 agonist, pregnenolone sulfate (PS). In particular, a single application of CIM0216 causes opening of both the central calcium-conducting pore and the alternative cation permeation pathway in a membrane-delimited manner. CIM0216 evoked robust calcium influx in TRPM3-expressing somatosensory neurons, and intradermal injection of the compound induced a TRPM3-dependent nocifensive behavior. Moreover, CIM0216 elicited the release of the peptides calcitonin gene-related peptide (CGRP) from sensory nerve terminals and insulin from isolated pancreatic islets in a TRPM3-dependent manner. These experiments identify CIM0216 as a powerful tool for use in investigating the physiological roles of TRPM3, and indicate that TRPM3 activation in sensory nerve endings can contribute to neurogenic inflammation.

  8. Trop-2-targeting tetrakis-ranpirnase has potent antitumor activity against triple-negative breast cancer

    PubMed Central

    2014-01-01

    Background Ranpirnase (Rap) is an amphibian ribonuclease with reported antitumor activity, minimal toxicity, and negligible immunogenicity in clinical studies, but the unfavorable pharmacokinetics and suboptimal efficacy hampered its further clinical development. To improve the potential of Rap-based therapeutics, we have used the DOCK-AND-LOCK™ (DNL™) method to construct a class of novel IgG-Rap immunoRNases. In the present study, a pair of these constructs, (Rap)2-E1-(Rap)2 and (Rap)2-E1*-(Rap)2, comprising four copies of Rap linked to the CH3 and CK termini of hRS7 (humanized anti-Trop-2), respectively, were evaluated as potential therapeutics for triple-negative breast cancer (TNBC). Methods The DNL-based immunoRNases, (Rap)2-E1-(Rap)2 and (Rap)2-E1*-(Rap)2, were characterized and tested for biological activities in vitro on a panel of breast cancer cell lines and in vivo in a MDA-MB-468 xenograft model. Results (Rap)2-E1-(Rap)2 was highly purified (>95%), exhibited specific cell binding and rapid internalization in MDA-MB-468, a Trop-2-expressing TNBC line, and displayed potent in vitro cytotoxicity (EC50 ≤ 1 nM) against diverse breast cancer cell lines with moderate to high expression of Trop-2, including MDA-MB-468, BT-20, HCC1806, SKBR-3, and MCF-7. In comparison, structural counterparts of (Rap)2-E1-(Rap)2, generated by substituting hRS7 with selective non-Trop-2-binding antibodies, such as epratuzumab (anti-CD22), were at least 50-fold less potent than (Rap)2-E1-(Rap)2 in MDA-MB-468 and BT-20 cells, both lacking the expression of the cognate antigen. Moreover, (Rap)2-E1-(Rap)2 was less effective (EC50 > 50 nM) in MDA-MB-231 (low Trop-2) or HCC1395 (no Trop-2), and did not show any toxicity to human peripheral blood mononuclear cells. In a mouse TNBC model, a significant survival benefit was achieved with (Rap)2-E1*-(Rap)2 when given the maximal tolerated dose. Conclusions A new class of immunoRNases was generated with enhanced potency for

  9. Iridoids from Canthium subcordatum iso-butanol fraction with potent biological activities.

    PubMed

    Joubouhi, Christelle; Tamokou, Jean-de-Dieu; Ngnokam, David; Voutquenne-Nazabadioko, Laurence; Kuiate, Jules-Roger

    2017-01-05

    The continuous emergence of multi-drug-resistant bacteria drastically reduces the efficacy of antibiotic armory and, consequently, increases the frequency of therapeutic failure. The discovery of new antibacterial drugs is an urgent need. The present study reports the antibacterial and antioxidant activities of the methanol extract, fractions and iridoids from Canthium subcordatum, a plant traditionally used as antidiabetic, anti-inflammatory, and antimicrobial. Broth microdilution assay was used to determine minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of extracts and iridoids against Staphylococcus aureus, Vibrio cholerae and Shigella flexneri. Antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and gallic acid equivalent antioxidant capacity (GAEAC) assays. The samples were also tested for their cytotoxicity against human red blood cells (RBC). The methanol extract, hexane, ethyl acetate and iso-butanol fractions from C. subcordatum fruits displayed different degrees of antioxidant (EC50 = 62.83-70.17 μg/ml; GAEAC = 45.63-58.23 μg/ml) and antibacterial (MIC = 128-512 μg/ml) activities. Canthiumoside 1(1) and linearin (7) were the most active antioxidant (EC50 = 1.12-2.03 μg/ml; GAEAC = 79.82-92.35 μg/ml) and antibacterial (MIC = 8-64 μg/ml) compounds while the most sensitive bacterium was Staphylococcus aureus. The tested samples were non-toxic to normal cells. Our results demonstrated that compounds 1 and 7 were potent antibacterial agents and DPPH/ABTS·(+) radical scavengers, so they warrant further investigation.

  10. Ecteinascidin-743, a new marine natural product with potent antitumor activity on human ovarian carcinoma xenografts.

    PubMed

    Valoti, G; Nicoletti, M I; Pellegrino, A; Jimeno, J; Hendriks, H; D'Incalci, M; Faircloth, G; Giavazzi, R

    1998-08-01

    The antitumor activity of ecteinascidin (ET)-743, a novel marine natural product, was evaluated against a panel of human ovarian carcinoma xenografts characterized by different malignant behaviors and drug responsiveness in nude mice. These tumor models included three xenografts transplanted s.c. (HOC18, HOC22-S, and MNB-PTX-1) into nude mice, representing different levels of sensitivity to cisplatinum (DDP), which was used as reference drug for ovarian carcinoma, and two other xenografts (HOC22 and HOC8), which are highly malignant in the peritoneal cavity of nude mice, representing the growth pattern of this neoplasm. At the maximum tolerated dose of 0.2 mg/kg using an intermittent schedule of one i.v. injection every 4 days, ET-743 was highly active against HOC22-S (sensitive to DDP), inducing long-lasting, complete regressions, and against HOC18 (marginally sensitive to DDP), inducing partial tumor regressions. Moreover, significant growth delay was observed in mice bearing late-stage HOC18 tumor (400-mg tumor weight; nonresponsive to DDP). ET-743, however, was not active against MNB-PTX-1, a tumor that is highly resistant to chemotherapy, including DDP. In the i.p. ovarian carcinoma xenograft model, ET-743 at the maximum tolerated dose induced complete tumor remissions in all mice bearing HOC22 tumor, with 25% histopathologically confirmed cures, and produced marginal tumor growth delay against HOC8. These results indicate that ET-743 is a potent drug against ovarian carcinoma xenografts, being equally as active or more efficacious than DDP in the same tumor line. Our findings with human ovarian carcinoma xenografts justify clinical assessment of this drug with this tumor target.

  11. Synthesis and biological evaluation of diarylthiazole derivatives as antimitotic and antivascular agents with potent antitumor activity.

    PubMed

    Wang, Fang; Yang, Zhuang; Liu, Yibin; Ma, Liang; Wu, Yuzhe; He, Lin; Shao, Mingfeng; Yu, Kun; Wu, Wenshuang; Pu, Yuzhi; Nie, Chunlai; Chen, Lijuan

    2015-07-01

    By switching position of the N and S atom in the thiazole ring which were similar to the previously reported agent 5-(4-ethoxyphenyl)-4-(3',4',5'-trimethoxyphenyl)thiazol-2-amine, a series of 4,5-diarylthiazole derivatives were synthesized using Friedel-Crafts reaction based on chemical modification of Combrestatatin A-4 (CA-4). Their antiproliferative activities were evaluated and identified as new microtubule destabilizing agents. Structure-activity relationship study indicated that compound 8a with 3,4,5-trimethoxyphenyl group at the C-4 position and 4-ethoxyphenyl group at the C-5 position of 2-amino substituted thiazole was of the most potent inhibitory activity in this series. 8a was found to exhibit the IC50 values of 8.4-26.4nM in five human cancer cell lines, with comparable inhibition effects to CA-4. Moreover, 8a showed potency as a tubulin polymerization inhibitor, with colchicine site binding ability and comparable extent of inhibition against the growth of P-glycoprotein over-expressing multidrug resistant cell lines. Mechanism studies revealed that 8a could block the progression of cell cycle in the G2/M phase and result in cellular apoptosis in cancer cells. As a new tubulin destabilizing agent, 8a was also found high antivascular activity as it concentration-dependently reduced the cell migration and disrupted capillary like tube formation of HUVEC cells. Furthermore, 8a significantly suppressed the tumor growth in HCT116 and SK-OV-3 xenograft models with tumor growth inhibitory rate of 55.12% and 72.7%, respectively. Our studies highlighted that 8a was a promising microtubule targeting antitumor agent.

  12. Potent Plasmodium falciparum Gametocytocidal Activity of Diaminonaphthoquinones, Lead Antimalarial Chemotypes Identified in an Antimalarial Compound Screen

    PubMed Central

    Tanaka, Takeshi Q; Guiguemde, W. Armand; Barnett, David S.; Maron, Maxim I.; Min, Jaeki; Connelly, Michele C.; Suryadevara, Praveen Kumar; Guy, R. Kiplin

    2014-01-01

    Forty percent of the world's population is threatened by malaria, which is caused by Plasmodium parasites and results in an estimated 200 million clinical cases and 650,000 deaths each year. Drug resistance has been reported for all commonly used antimalarials and has prompted screens to identify new drug candidates. However, many of these new candidates have not been evaluated against the parasite stage responsible for transmission, gametocytes. If Plasmodium falciparum gametocytes are not eliminated, patients continue to spread malaria for weeks after asexual parasite clearance. Asymptomatic individuals can also harbor gametocyte burdens sufficient for transmission, and a safe, effective gametocytocidal agent could also be used in community-wide malaria control programs. Here, we identify 15 small molecules with nanomolar activity against late-stage gametocytes. Fourteen are diaminonaphthoquinones (DANQs), and one is a 2-imino-benzo[d]imidazole (IBI). One of the DANQs identified, SJ000030570, is a lead antimalarial candidate. In contrast, 94% of the 650 compounds tested are inactive against late-stage gametocytes. Consistent with the ineffectiveness of most approved antimalarials against gametocytes, of the 19 novel compounds with activity against known anti-asexual-stage targets, only 3 had any strong effect on gametocyte viability. These data demonstrate the distinct biology of the transmission stages and emphasize the importance of screening for gametocytocidal activity. The potent gametocytocidal activity of DANQ and IBI coupled with their efficacy against asexual parasites provides leads for the development of antimalarials with the potential to prevent both the symptoms and the spread of malaria. PMID:25512421

  13. Potent Plasmodium falciparum gametocytocidal activity of diaminonaphthoquinones, lead antimalarial chemotypes identified in an antimalarial compound screen.

    PubMed

    Tanaka, Takeshi Q; Guiguemde, W Armand; Barnett, David S; Maron, Maxim I; Min, Jaeki; Connelly, Michele C; Suryadevara, Praveen Kumar; Guy, R Kiplin; Williamson, Kim C

    2015-03-01

    Forty percent of the world's population is threatened by malaria, which is caused by Plasmodium parasites and results in an estimated 200 million clinical cases and 650,000 deaths each year. Drug resistance has been reported for all commonly used antimalarials and has prompted screens to identify new drug candidates. However, many of these new candidates have not been evaluated against the parasite stage responsible for transmission, gametocytes. If Plasmodium falciparum gametocytes are not eliminated, patients continue to spread malaria for weeks after asexual parasite clearance. Asymptomatic individuals can also harbor gametocyte burdens sufficient for transmission, and a safe, effective gametocytocidal agent could also be used in community-wide malaria control programs. Here, we identify 15 small molecules with nanomolar activity against late-stage gametocytes. Fourteen are diaminonaphthoquinones (DANQs), and one is a 2-imino-benzo[d]imidazole (IBI). One of the DANQs identified, SJ000030570, is a lead antimalarial candidate. In contrast, 94% of the 650 compounds tested are inactive against late-stage gametocytes. Consistent with the ineffectiveness of most approved antimalarials against gametocytes, of the 19 novel compounds with activity against known anti-asexual-stage targets, only 3 had any strong effect on gametocyte viability. These data demonstrate the distinct biology of the transmission stages and emphasize the importance of screening for gametocytocidal activity. The potent gametocytocidal activity of DANQ and IBI coupled with their efficacy against asexual parasites provides leads for the development of antimalarials with the potential to prevent both the symptoms and the spread of malaria. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. An Enterotoxin-like Binary Protein from Pseudomonas protegens with Potent Nematicidal Activity.

    PubMed

    Wei, Jun-Zhi; Siehl, Daniel L; Hou, Zhenglin; Rosen, Barbara; Oral, Jarred; Taylor, Christopher G; Wu, Gusui

    2017-07-21

    Soil microbes are a major food source for free-living soil nematodes. It is known that certain soil bacteria have evolved systems to combat predation. We identified the nematode-antagonistic Pseudomonas protegens strain 15G2 from screening of microbes. Through protein purification we identified a binary protein, designated as Pp-ANP, that is responsible for the nematicidal activity. This binary protein inhibits Caenorhabditis elegans growth and development by arresting larvae at L1 stage and killing older staged worms. The two subunits, Pp-ANP1a and Pp-ANP2a are active when reconstituted from separate expression in Escherichia coli The binary toxin also shows strong nematicidal activity against three other free-living nematodes, Pristionchus pacificus, Panagrellus redivivus, and Acrobeloides sp., but no activity was found for insects and fungi under test conditions, indicating specificity for nematodes. Pp-ANP1a has no significant homology to any known proteins, while Pp-ANP2a shows ∼30% homology to E. coli heat-labile enterotoxin (LT) subunit A and cholera toxin (CT) subunit A. Protein modeling indicates Pp-ANP2a is structurally similar to CT/LT and likely acts as a ADP-ribosyltransferase. Despite the similarity, Pp-ANP shows several characteristics distinct from CT/LT toxins. Our results indicate that Pp-ANP is a new enterotoxin-like binary toxin with potent and specific activity to nematodes. The potency and specificity of Pp-ANP suggests applications in controlling parasitic nematodes and opens an avenue for further research on its mechanism of action and role in bacterium-nematode interaction.IMPORTANCE This study reports the discovery of a new enterotoxin-like binary protein, Pp-ANP from a Pseudomonas protegens strain. Pp-ANP shows strong nematicidal activity against Caenorhabditis elegans larvae and older staged worms. It also shows strong activity on other free-living nematodes, Pristionchus pacificus, Panagrellus redivivus, and Acrobeloides sp. The two

  15. Triterpenoids isolated from apple peels have potent antiproliferative activity and may be partially responsible for apple's anticancer activity.

    PubMed

    He, Xiangjiu; Liu, Rui Hai

    2007-05-30

    Bioactivity-guided fractionation of apple peels was used to determine the chemical identity of bioactive constituents. Thirteen triterpenoids were isolated, and their chemical structures were identified. Antiproliferative activities of the triterpenoids against human HepG2 liver cancer cells, MCF-7 breast cancer cells, and Caco-2 colon cancer cells were evaluated. Most of the triterpenoids showed high potential anticancer activities against the three human cancer cell lines. Among the compounds isolated, 2alpha-hydroxyursolic acid, 2alpha-hydroxy-3beta-{[(2E)-3-phenyl-1-oxo-2-propenyl]oxy}olean-12-en-28-oic acid, and 3beta-trans-p-coumaroyloxy-2alpha-hydroxyolean-12-en-28-oic acid showed higher antiproliferative activity toward HepG2 cancer cells. Ursolic acid, 2alpha-hydroxyursolic acid, and 3beta-trans-p-coumaroyloxy-2alpha-hydroxyolean-12-en-28-oic acid exhibited higher antiproliferative activity against MCF-7 cancer cells. All triterpenoids tested showed antiproliferative activity against Caco-2 cancer cells, especially 2alpha-hydroxyursolic acid, maslinic acid, 2alpha-hydroxy-3beta-{[(2E)-3-phenyl-1-oxo-2-propenyl]oxy}olean-12-en-28-oic acid, and 3beta-trans-p-coumaroyloxy-2alpha-hydroxyolean-12-en-28-oic acid, which displayed much higher antiproliferative activities. These results showed the triterpenoids isolated from apple peels have potent antiproliferative activity and may be partially responsible for the anticancer activities of whole apples.

  16. Potent anti-muscarinic activity in a novel series of quinuclidine derivatives.

    PubMed

    Starck, Jean-Philippe; Talaga, Patrice; Quéré, Luc; Collart, Philippe; Christophe, Bernard; Lo Brutto, Patrick; Jadot, Sophie; Chimmanamada, Dinesh; Zanda, Matteo; Wagner, Alain; Mioskowski, Charles; Massingham, Roy; Guyaux, Michel

    2006-01-15

    The synthesis and biological evaluation of a novel family of M(3) muscarinic antagonists are described. A systematic modification of the substituents to a novel alkyne-quinuclidine scaffold yielded original compounds displaying potent in vitro anticholinergic properties.

  17. Allorestricted cytotoxic T cells specific for human CD45 show potent antileukemic activity.

    PubMed

    Amrolia, Persis J; Reid, Steven D; Gao, Liquan; Schultheis, Beate; Dotti, Gianpietro; Brenner, Malcolm K; Melo, Junia V; Goldman, John M; Stauss, Hans J

    2003-02-01

    Recent advances have made haploidentical transplantation for leukemia feasible, but the rigorous T-cell depletion used contributes to the high relapse rates observed. We have attempted to improve the graft-versus-leukemia (GVL) effect by generating allorestricted cytotoxic T lymphocytes (CTLs) directed against human CD45. Such CTLs should recognize patient hematopoietic cells including leukemia, enhancing donor cell engraftment and improving the GVL effect, but they should not recognize host nonhematopoietic tissues or donor cells from the graft. Using the T2 binding assay, 4 CD45-derived peptides were found to bind HLA-A2 molecules. These peptides were used to generate cytotoxic T-cell lines from HLA-A2(-) donors by sequential stimulation with peptide-pulsed HLA-A2(+) stimulators, and the lines obtained were screened for peptide-specific cytotoxicity. Using one of these peptides (P1218), it was possible to generate peptide-specific, allorestricted CTLs in 3 of 7 responders. P1218-specific CTL lines show potent cytotoxicity against hematopoietic cell lines coexpressing HLA-A2 and CD45 but not CD45 loss variants. Studies with stable transfectants of 293 cells demonstrated recognition by P1218-specific CTLs of endogenously expressed CD45. Likewise P1218-specific CTLs recognized peripheral blood mononuclear cells (PBMCs) from HLA-A2(+) patients with chronic myeloid leukemia (CML) and leukemic blasts in HLA-A2(+) patients with acute myeloid leukemia (AML), but they were unable to lyse HLA-A2(+) fibroblasts or HLA-A2(-) normal PBMCs. Coculture of CD34(+) PBMCs and bone marrow mononuclear cells (BMMCs) with P1218-specific CTL significantly inhibited colony-forming unit-granulocyte macrophage (CFU-GM) formation in HLA-A2(+) healthy controls and CML patients but resulted in no significant inhibition in HLA-A2(-) healthy controls. These studies demonstrate that P1218-specific cytotoxic T lymphocytes (CTLs) have potent activity against leukemic progenitors and suggest that

  18. Characterization of the biological activity of a potent small molecule Hec1 inhibitor TAI-1

    PubMed Central

    2014-01-01

    Background Hec1 (NDC80) is an integral part of the kinetochore and is overexpressed in a variety of human cancers, making it an attractive molecular target for the design of novel anticancer therapeutics. A highly potent first-in-class compound targeting Hec1, TAI-1, was identified and is characterized in this study to determine its potential as an anticancer agent for clinical utility. Methods The in vitro potency, cancer cell specificity, synergy activity, and markers for response of TAI-1 were evaluated with cell lines. Mechanism of action was confirmed with western blotting and immunofluorescent staining. The in vivo potency of TAI-1 was evaluated in three xenograft models in mice. Preliminary toxicity was evaluated in mice. Specificity to the target was tested with a kinase panel. Cardiac safety was evaluated with hERG assay. Clinical correlation was performed with human gene database. Results TAI-1 showed strong potency across a broad spectrum of tumor cells. TAI-1 disrupted Hec1-Nek2 protein interaction, led to Nek2 degradation, induced significant chromosomal misalignment in metaphase, and induced apoptotic cell death. TAI-1 was effective orally in in vivo animal models of triple negative breast cancer, colon cancer and liver cancer. Preliminary toxicity shows no effect on the body weights, organ weights, and blood indices at efficacious doses. TAI-1 shows high specificity to cancer cells and to target and had no effect on the cardiac channel hERG. TAI-1 is synergistic with doxorubicin, topotecan and paclitaxel in leukemia, breast and liver cancer cells. Sensitivity to TAI-1 was associated with the status of RB and P53 gene. Knockdown of RB and P53 in cancer cells increased sensitivity to TAI-1. Hec1-overexpressing molecular subtypes of human lung cancer were identified. Conclusions The excellent potency, safety and synergistic profiles of this potent first-in-class Hec1-targeted small molecule TAI-1 show its potential for clinically utility in anti

  19. The most potent organophosphorus inhibitors of leucine aminopeptidase. Structure-based design, chemistry, and activity.

    PubMed

    Grembecka, Jolanta; Mucha, Artur; Cierpicki, Tomasz; Kafarski, Paweł

    2003-06-19

    A new class of very potent inhibitors of cytosol leucine aminopeptidase (LAP), a member of the metalloprotease family, is described. The X-ray structure of bovine lens leucine aminopeptidase complexed with the phosphonic acid analogue of leucine (LeuP) was used for structure-based design of novel LAP inhibitors and for the analysis of their interactions with the enzyme binding site. The inhibitors were designed by modification of phosphonic group in the LeuP structure toward finding the substituents bound at the S' side of the enzyme. This resulted in two classes of compounds, the phosphonamidate and phosphinate dipeptide analogues, which were synthesized and evaluated as inhibitors of the enzyme. The in vitro kinetic studies for the phosphinate dipeptide analogues revealed that these compounds belong to the group of the most effective LAP inhibitors found so far. Their further modification at the P1 position resulted in more active inhibitors, hPheP[CH(2)]Phe and hPheP[CH(2)]Tyr (K(i) values 66 nM and 67 nM, respectively, for the mixture of four diastereomers). The binding affinities of these inhibitors toward the enzyme are the highest, if considering all compounds containing a phosphorus atom that mimic the transition state of the reaction catalyzed by LAP. To evaluate selectivity of the designed LAP inhibitors, additional tests toward aminopeptidase N (APN) were performed. The key feature, which determines their selectivity, is structure at the P1' position. Aromatic and aliphatic substituents placed at this position strongly interact with the LAP S1' binding pocket, while a significant increase in binding affinity toward APN was observed for compounds containing aromatic versus leucine side chains at the P1' position. The most selective inhibitor, hPheP[CH(2)]Leu, binds to LAP with 15 times higher affinity than to APN. One of the studied compounds, hPheP[CH(2)]Tyr, appeared to be very potent inhibitor of APN (K(i) = 36 nM for the mixture of four diastereomers

  20. Novel Synthesis of Kanamycin Conjugated Gold Nanoparticles with Potent Antibacterial Activity

    PubMed Central

    Payne, Jason N.; Waghwani, Hitesh K.; Connor, Michael G.; Hamilton, William; Tockstein, Sarah; Moolani, Harsh; Chavda, Fenil; Badwaik, Vivek; Lawrenz, Matthew B.; Dakshinamurthy, Rajalingam

    2016-01-01

    With a sharp increase in the cases of multi-drug resistant (MDR) bacteria all over the world, there is a huge demand to develop a new generation of antibiotic agents to fight them. As an alternative to the traditional drug discovery route, we have designed an effective antibacterial agent by modifying an existing commercial antibiotic, kanamycin, conjugated on the surface of gold nanoparticles (AuNPs). In this study, we report a single-step synthesis of kanamycin-capped AuNPs (Kan-AuNPs) utilizing the combined reducing and capping properties of kanamycin. While Kan-AuNPs have increased toxicity to a primate cell line (Vero 76), antibacterial assays showed dose-dependent broad spectrum activity of Kan-AuNPs against both Gram-positive and Gram-negative bacteria, including Kanamycin resistant bacteria. Further, a significant reduction in the minimum inhibitory concentration (MIC) of Kan-AuNPs was observed when compared to free kanamycin against all the bacterial strains tested. Mechanistic studies using transmission electron microscopy and fluorescence microscopy indicated that at least part of Kan-AuNPs increased efficacy may be through disrupting the bacterial envelope, resulting in the leakage of cytoplasmic content and the death of bacterial cells. Results of this study provide critical information about a novel method for the development of antibiotic capped AuNPs as potent next-generation antibacterial agents. PMID:27330535

  1. Green synthesis of silk sericin-capped silver nanoparticles and their potent anti-bacterial activity

    NASA Astrophysics Data System (ADS)

    Aramwit, Pornanong; Bang, Nipaporn; Ratanavaraporn, Juthamas; Ekgasit, Sanong

    2014-02-01

    In this study, a `green chemistry' approach was introduced to synthesize silk sericin (SS)-capped silver nanoparticles (AgNPs) under an alkaline condition (pH 11) using SS as a reducing and stabilizing agent instead of toxic chemicals. The SS-capped AgNPs were successfully synthesized at various concentrations of SS and AgNO3, but the yields were different. A higher yield of SS-capped AgNPs was obtained when the concentrations of SS and AgNO3 were increased. The SS-capped AgNPs showed a round shape and uniform size with diameter at around 48 to 117 nm. The Fourier transform infrared (FT-IR) spectroscopy result proved that the carboxylate groups obtained from alkaline degradation of SS would be a reducing agent for the generation of AgNPs while COO- and NH2 + groups stabilized the AgNPs and prevented their precipitation or aggregation. Furthermore, the SS-capped AgNPs showed potent anti-bacterial activity against various gram-positive bacteria (minimal inhibitory concentration (MIC) 0.008 mM) and gram-negative bacteria (MIC ranging from 0.001 to 0.004 mM). Therefore, the SS-capped AgNPs would be a safe candidate for anti-bacterial applications.

  2. A novel polypeptide from shark cartilage with potent anti-angiogenic activity.

    PubMed

    Zheng, Lanhong; Ling, Peixue; Wang, Zheng; Niu, Rongli; Hu, Chaoxin; Zhang, Tianmin; Lin, Xiukun

    2007-05-01

    Using guanidine-HCl extraction, acetone precipitation, ultra-filtration and chromatography, a novel polypeptide with potent anti-angiogenic activity was purified from cartilage of the shark, Prionace glauca. N-terminal amino acid sequence analysis and SDS-PAGE revealed that the substance is a novel polypeptide with MW 15500 (PG155). The anti-angiogenic effects of PG155 were evaluated using zebrafish embryos model in vivo. Treatment of the embryos with 20 microg/ml PG155 resulted in a significant reduction in the growth of subintestinal vessels (SIVs). A higher dose resulted in almost complete inhibition of SIV growth, as observed by endogenous alkaline phosphatase (EAP) staining assay. An in vitro transwell experiment revealed that the polypeptide inhibited vascular endothelial growth factor (VEGF) induced migration and tubulogenesis of human umbilical vein endothelial cells (HUVECs). Exposure of HUVECs in 20 microg/ml PG155 significantly decreased the density of migrated cells. Almost complete inhibition of cell migration was found when HUVECs were treated with 40-80 microg/ml PG155. PG155 (20 microg/ml) markedly inhibited the tube formation of HUVECs and a dose-dependent effect was also found when treatment of HUVECs with PG155 at the concentration from 20-160 microg/ml.

  3. Potent antitumor activity of double-regulated oncolytic adenovirus-mediated ST13 for colorectal cancer.

    PubMed

    Yu, De Bin; Zhong, Su Yang; Yang, Min; Wang, Yi Gang; Qian, Qi Jun; Zheng, Shu; Liu, Xin Yuan

    2009-04-01

    Following targeted gene virotherapy, the suppression of tumorigenicity 13 (ST13) gene was inserted into the double-regulated oncolytic adenovirus SG500 to ensure more safety and potent antitumor activity against colorectal cancer in vitro and in vivo. We generated the ST13-expressing oncolytic adenovirus SG500-ST13, with which colorectal carcinoma cell lines SW620 and HCT116, and the lung fibroblast cell line WI38, were infected. Crystal violet staining was carried out to detect the cytopathic effect in cells, and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method was used to assay cell viability. The effect of apoptosis induced by SG500-ST13 was confirmed by Hoechst staining and the TdT-mediated dUTP-biotin nick-end labeling method. To further identify the antitumor effects of SG500-ST13 on HCT116 xenografts in Balb/c nude mice, the induction of cell death was assessed by hematoxylin-eosin staining. Immunohistochemical study was also carried out.

  4. Glycosylated enfuvirtide: a long-lasting glycopeptide with potent anti-HIV activity.

    PubMed

    Cheng, Shuihong; Chang, Xuesong; Wang, Yan; Gao, George F; Shao, Yiming; Ma, Liying; Li, Xuebing

    2015-02-12

    Many peptide-based therapeutics have short circulatory half-lives. We report here that the pharmacokinetics of an anti-HIV peptide drug enfuvirtide (ENF) can be dramatically improved by a chemical glycosylation approach. A set of glycosylated ENFs with varying glycosylation sites and glycan structures were synthesized. Among these, a sialic acid-introduced peptide (SL-ENF) demonstrated a 15-fold extended half-life in rats relative to ENF (T1/2: 23.1 vs 1.5 h), and its antiviral potency was comparable to that of ENF (EC50: 2 vs 3 nM). SL-ENF bound to a functional fragment of the HIV fusogenic protein gp41 and formed complexes with high affinity and α-helicity, revealing the mechanism behind its potent antiviral activity. Because it is widely accepted in biology that glycosylation protects proteins from denaturation and proteases, our approach may be useful for the development of novel protein and peptide drugs with enhanced pharmaceutical properties.

  5. Two hevein homologs isolated from the seed of Pharbitis nil L. exhibit potent antifungal activity.

    PubMed

    Koo, J C; Lee, S Y; Chun, H J; Cheong, Y H; Choi, J S; Kawabata, S; Miyagi, M; Tsunasawa, S; Ha, K S; Bae, D W; Han, C D; Lee, B L; Cho, M J

    1998-01-15

    Two antifungal peptides (Pn-AMP1 and Pn-AMP2) have been purified to homogeneity from seeds of Pharbitis nil. The amino acid sequences of Pn-AMP1 (41 amino acid0 residues) and Pn-AMP2 (40 amino acid residues) were identical except that Pn-AMP1 has an additional serine residue at the carboxyl-terminus. The molecular masses of Pn-AMP1 and Pn-AMP2 were confirmed as 4299.7 and 4213.2 Da, respectively. Both the Pn-AMPs were highly basic (pI 12.02) and had characteristics of cysteine/glycine rich chitin-binding domain. Pn-AMPs exhibited potent antifungal activity against both chitin-containing and non-chitin-containing fungi in the cell wall. Concentrations required for 50% inhibition of fungal growth were ranged from 3 to 26 micrograms/ml for Pn-AMP1 and from 0.6 to 75 micrograms/ml for Pn-AMP2. The Pn-AMPs penetrated very rapidly into fungal hyphae and localized at septum and hyphal tips of fungi, which caused burst of hyphal tips. Burst of hyphae resulted in disruption of the fungal membrane and leakage of the cytoplasmic materials. To our knowledge, Pn-AMPs are the first hevein-like proteins that show similar fungicidal effects as thionins do.

  6. Designed, Synthetically Accessible Bryostatin Analogues Potently Induce Activation of Latent HIV Reservoirs in vitro

    PubMed Central

    DeChristopher, Brian A.; Loy, Brian A.; Marsden, Matthew D.; Schrier, Adam J.; Zack, Jerome A.

    2012-01-01

    Bryostatin is a unique lead in the development of potentially transformative therapies for cancer, Alzheimer’s disease, and the eradication of HIV/AIDS. However, the clinical use of bryostatin has been hampered by its limited supply, difficulties in accessing clinically-relevant derivatives, and side effects. Herein, we address these problems through the step-economical syntheses of seven members of a new family of designed bryostatin analogues utilizing a highly convergent Prins-macrocyclization strategy. We also demonstrate for the first time that such analogues effectively induce latent HIV activation in vitro with potencies similar to or better than bryostatin. Significantly, these analogues are up to 1000-fold more potent in inducing latent HIV expression than prostratin, the current clinical candidate for latent virus induction. This study provides the first demonstration that designed, synthetically-accessible bryostatin analogues could serve as superior candidates for the eradication of HIV/AIDS through induction of latent viral reservoirs in conjunction with current antiretroviral therapy. PMID:22914190

  7. Novel Synthesis of Kanamycin Conjugated Gold Nanoparticles with Potent Antibacterial Activity.

    PubMed

    Payne, Jason N; Waghwani, Hitesh K; Connor, Michael G; Hamilton, William; Tockstein, Sarah; Moolani, Harsh; Chavda, Fenil; Badwaik, Vivek; Lawrenz, Matthew B; Dakshinamurthy, Rajalingam

    2016-01-01

    With a sharp increase in the cases of multi-drug resistant (MDR) bacteria all over the world, there is a huge demand to develop a new generation of antibiotic agents to fight them. As an alternative to the traditional drug discovery route, we have designed an effective antibacterial agent by modifying an existing commercial antibiotic, kanamycin, conjugated on the surface of gold nanoparticles (AuNPs). In this study, we report a single-step synthesis of kanamycin-capped AuNPs (Kan-AuNPs) utilizing the combined reducing and capping properties of kanamycin. While Kan-AuNPs have increased toxicity to a primate cell line (Vero 76), antibacterial assays showed dose-dependent broad spectrum activity of Kan-AuNPs against both Gram-positive and Gram-negative bacteria, including Kanamycin resistant bacteria. Further, a significant reduction in the minimum inhibitory concentration (MIC) of Kan-AuNPs was observed when compared to free kanamycin against all the bacterial strains tested. Mechanistic studies using transmission electron microscopy and fluorescence microscopy indicated that at least part of Kan-AuNPs increased efficacy may be through disrupting the bacterial envelope, resulting in the leakage of cytoplasmic content and the death of bacterial cells. Results of this study provide critical information about a novel method for the development of antibiotic capped AuNPs as potent next-generation antibacterial agents.

  8. Platelet-activating factor acetylhydrolase: selective inhibition by potent n-alkyl methylphosphonofluoridates.

    PubMed

    Quistad, Gary B; Fisher, Karl J; Owen, Sarah C; Klintenberg, Rebecka; Casida, John E

    2005-06-01

    Platelet-activating factor (PAF) is a potent endogenous phospholipid modulator of diverse biological activities, including inflammation and shock. PAF levels are primarily regulated by PAF acetylhydrolases (PAF-AHs). These enzymes are candidate secondary targets of organophosphorus (OP) pesticides and related toxicants. Previously known OP inhibitors of other serine hydrolases were tested with PAF-AH from mouse brain and testes of established functional importance compared with the structurally different human plasma enzyme. Several key OP pesticides and their oxon metabolites were very poor inhibitors of mouse brain and human plasma PAF-AH in vitro but moderately active for mouse brain and blood PAF-AH in vivo (e.g., tribufos defoliant and profenofos insecticide, presumably following oxidative bioactivation). OP compounds were then designed for maximum in vitro potency and selectivity for mouse brain PAF-AH vs. acetylcholinesterase (AChE). Lead compounds were found in a series of benzodioxaphosphorin 2-oxides. Ultrahigh potency and selectivity were achieved with n-alkyl methylphosphonofluoridates (long-chain sarin analogs): mouse brain and testes IC50 < or = 5 nM for C(8)-C(18) analogs and 0.1-0.6 nM for C(13) and C(14) compounds; human plasma IC50 < or = 2 nM for C(13)-C(18) analogs. AChE inhibitory potency decreased as chain length increased with maximum brain PAF-AH/AChE selectivity (>3000-fold) for C(13)-C(18) compounds. The toxicity of i.p.-administered PAF (LD50 ca. 0.5 mg/kg) was increased less than 2-fold by pretreatment with tribufos or the C(13)n-alkyl methylphosphonofluoridate. These studies with a mouse model indicate that PAF-AH is not a major secondary target of OP pesticide poisoning. The optimized PAF-AH inhibitors may facilitate investigations on other aspects of PAF metabolism and action.

  9. Effect of Complement on HIV-2 Plasma Antiviral Activity Is Intratype Specific and Potent

    PubMed Central

    Özkaya Şahin, Gülşen; Holmgren, Birgitta; Sheik-Khalil, Enas; da Silva, Zacarias; Nielsen, Jens; Nowroozalizadeh, Salma; Månsson, Fredrik; Norrgren, Hans; Aaby, Peter; Fenyö, Eva Maria

    2013-01-01

    Human immunodeficiency virus type 2 (HIV-2)-infected individuals develop immunodeficiency with a considerable delay and transmit the virus at rates lower than HIV-1-infected persons. Conceivably, comparative studies on the immune responsiveness of HIV-1- and HIV-2-infected hosts may help to explain the differences in pathogenesis and transmission between the two types of infection. Previous studies have shown that the neutralizing antibody response is more potent and broader in HIV-2 than in HIV-1 infection. In the present study, we have examined further the function of the humoral immune response and studied the effect of complement on the antiviral activity of plasma from singly HIV-1- or HIV-2-infected individuals, as well as HIV-1/HIV-2 dually infected individuals. The neutralization and antibody-dependent complement-mediated inactivation of HIV-1 and HIV-2 isolates were tested in a plaque reduction assay using U87.CD4.CCR5 cells. The results showed that the addition of complement increased intratype antiviral activities of both HIV-1 and HIV-2 plasma samples, although the complement effect was more pronounced with HIV-2 than HIV-1 plasma. Using an area-under-the-curve (AUC)-based readout, multivariate statistical analysis confirmed that the type of HIV infection was independently associated with the magnitude of the complement effect. The analyses carried out with purified IgG indicated that the complement effect was largely exerted through the classical complement pathway involving IgG in both HIV-1 and HIV-2 infections. In summary, these findings suggest that antibody binding to HIV-2 structures facilitates the efficient use of complement and thereby may be one factor contributing to a strong antiviral activity present in HIV-2 infection. PMID:23077299

  10. A novel, potent, oral active and safe antinociceptive pyrazole targeting kappa opioid receptors.

    PubMed

    Trevisan, Gabriela; Rossato, Mateus F; Walker, Cristiani I B; Oliveira, Sara M; Rosa, Fernanda; Tonello, Raquel; Silva, Cássia R; Machado, Pablo; Boligon, Aline A; Martins, Marcos A P; Zanatta, Nilo; Bonacorso, Hélio G; Athayde, Margareth L; Rubin, Maribel A; Calixto, João B; Ferreira, Juliano

    2013-10-01

    Pyrazole compounds are an intriguing class of compounds with potential analgesic activity; however, their mechanism of action remains unknown. Thus, the goal of this study was to explore the antinociceptive potential, safety and mechanism of action of novel 1-pyrazole methyl ester derivatives, which were designed by molecular simplification, using in vivo and in vitro methods in mice. First, tree 1-pyrazole methyl ester derivatives (DMPE, MPFE, and MPCIE) were tested in the capsaicin test and all presented antinociceptive effect; however the MPClE (methyl 5-trichloromethyl-3-methyl-1H-pyrazole-1-carboxylate) was the most effective. Thus, we selected this compound to assess the effects and mechanisms in subsequent pain models. MPCIE produced antinociception when administered by oral, intraperitoneal, intrathecal and intraplantar routes and was effective in the capsaicin and the acetic acid-induced nociception tests. Moreover, this compound reduced the hyperalgesia in diverse clinically-relevant pain models, including postoperative, inflammatory, and neuropathic nociception in mice. The antinociception produced by orally administered MPClE was mediated by κ-opioid receptors, since these effects were prevented by systemically pre-treatment with naloxone and the κ-opioid receptor antagonist nor-binaltorphimine. Moreover, MPCIE prevented binding of the κ-opioid ligand [(3)H]-CI-977 in vitro (IC₅₀ of 0.68 (0.32-1.4) μM), but not the TRPV1 ([(3)H]-resiniferatoxin) or the α₂-adrenoreceptor ([(3)H]-idazoxan) binding. Regarding the drug-induced side effects, oral administration of MPClE did not produce sedation, constipation or motor impairment at its active dose. In addition, MPCIE was readily absorbed after oral administration. Taken together, these results demonstrate that MPClE is a novel, potent, orally active and safe analgesic drug that targets κ-opioid receptors.

  11. Structure-activity relationship for enantiomers of potent inhibitors of B. anthracis dihydrofolate reductase

    PubMed Central

    Bourne, Christina R.; Wakeham, Nancy; Nammalwar, Baskar; Tseitin, Vladimir; Bourne, Philip C.; Barrow, Esther W.; Mylvaganam, Shankari; Ramnarayan, Kal; Bunce, Richard A.; Berlin, K. Darrell; Barrow, William W.

    2012-01-01

    Background Bacterial resistance to antibiotic therapies is increasing and new treatment options are badly needed. There is an overlap between these resistant bacteria and organisms classified as likely bioterror weapons. For example, Bacillus anthracis is innately resistant to the anti-folate trimethoprim due to sequence changes found in the dihydrofolate reductase enzyme. Development of new inhibitors provides an opportunity to enhance the current arsenal of anti-folate antibiotics while also expanding the coverage of the anti-folate class. Methods We have characterized inhibitors of Bacillus anthracis dihydrofolate reductase by measuring the Ki and MIC values and calculating the energetics of binding. This series contains a core diaminopyrimidine ring, a central dimethoxybenzyl ring, and a dihydrophthalazine moiety. We have altered the chemical groups extended from a chiral center on the dihydropyridazine ring of the phthalazine moiety. The interactions for the most potent compounds were visualized by X-ray structure determination. Results We find that the potency of individual enantiomers is divergent with clear preference for the S-enantiomer, while maintaining a high conservation of contacts within the binding site. The preference for enantiomers seems to be predicated largely by differential interactions with protein residues Leu29, Gln30 and Arg53. Conclusions These studies have clarified the activity of modifications and of individual enantiomers, and highlighted the role of the less-active R-enantiomer in effectively diluting the more active S-enantiomer in racemic solutions. This directly contributes to the development of new antimicrobials, combating trimethoprim resistance, and treatment options for potential bioterrorism agents. PMID:22999981

  12. Structure-activity relationships for organometallic osmium arene phenylazopyridine complexes with potent anticancer activity.

    PubMed

    Fu, Ying; Habtemariam, Abraha; Basri, Aida M B H; Braddick, Darren; Clarkson, Guy J; Sadler, Peter J

    2011-10-28

    We report the synthesis and characterisation of 32 half sandwich phenylazopyridine Os(II) arene complexes [Os(η(6)-arene)(phenylazopyridine)X](+) in which X is chloride or iodide, the arene is p-cymene or biphenyl and the pyridine and phenyl rings contain a variety of substituents (F, Cl, Br, I, CF(3), OH or NO(2)). Ten X-ray crystal structures have been determined. Cytotoxicity towards A2780 human ovarian cancer cells ranges from high potency at nanomolar concentrations to inactivity. In general the introduction of an electron-withdrawing group (e.g. F, Cl, Br or I) at specific positions on the pyridine ring significantly increases cytotoxic activity and aqueous solubility. Changing the arene from p-cymene to biphenyl and the monodentate ligand X from chloride to iodide also increases the activity significantly. Activation by hydrolysis and DNA binding appears not to be the major mechanism of action since both the highly active complex [Os(η(6)-bip)(2-F-azpy)I]PF(6) (9) and the moderately active complex [Os(η(6)-bip)(3-Cl-azpy)I]PF(6) (23) are very stable and inert towards aquation. Studies of octanol-water partition coefficients (log P) and subcellular distributions of osmium in A2780 human ovarian cancer cells suggested that cell uptake and targeting to cellular organelles play important roles in determining activity. Although complex 9 induced the production of reactive oxygen species (ROS) in A2780 cells, the ROS level did not appear to play a role in the mechanism of anticancer activity. This class of organometallic osmium complexes has new and unusual features worthy of further exploration for the design of novel anticancer drugs.

  13. Curcumin-loaded polysaccharide nanoparticles: Optimization and anticariogenic activity against Streptococcus mutans.

    PubMed

    Maghsoudi, Amir; Yazdian, Fatemeh; Shahmoradi, Saleheh; Ghaderi, Leila; Hemati, Mehran; Amoabediny, Ghassem

    2017-06-01

    Curcumin was loaded into different polysaccharide nanoparticles chitosan, alginate and starch, using the desolvation method. Curcumin-loaded nanoparticles exhibited enhanced solubility in aqueous solutions comparing with free curcumin. Effects of formulation parameters such as curcumin concentration and different volumes of ethanolic solution were affected the particle size and loading efficiency. Under optimum conditions, curcumin-loaded chitosan, starch and alginate nanoparticles with mean particles sizes of 66.3, 61.1 and 78.8nm, and maximum loading efficiencies of 11.9%, 14.3% and 13.35% were achieved, respectively. Additionally, the minimum inhibitory concentration for chitosan, starch and alginate nanoparticles against the microorganism, Streptococcus mutans, were 0.114, 0.204 and 0.204mg/mL, respectively. Curcumin was observed to release from nanoparticles under physiological pH over a period of 96h. The effect of curcumin-loaded nanoparticles on S. mutans biofilms was assessed on dental models. According to the results, curcumin-loaded chitosan nanoparticles hold promises for being used in dental decay fighting products. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Discovery of novel protease activated receptors 1 antagonists with potent antithrombotic activity in vivo.

    PubMed

    Perez, Michel; Lamothe, Marie; Maraval, Catherine; Mirabel, Etienne; Loubat, Chantal; Planty, Bruno; Horn, Clemens; Michaux, Julien; Marrot, Sebastien; Letienne, Robert; Pignier, Christophe; Bocquet, Arnaud; Nadal-Wollbold, Florence; Cussac, Didier; de Vries, Luc; Le Grand, Bruno

    2009-10-08

    Protease activated receptors (PARs) or thrombin receptors constitute a class of G-protein-coupled receptors (GPCRs) implicated in the activation of many physiological mechanisms. Thus, thrombin activates many cell types such as vascular smooth muscle cells, leukocytes, endothelial cells, and platelets via activation of these receptors. In humans, thrombin-induced platelet aggregation is mediated by one subtype of these receptors, termed PAR1. This article describes the discovery of new antagonists of these receptors and more specifically two compounds: 2-[5-oxo-5-(4-pyridin-2-ylpiperazin-1-yl)penta-1,3-dienyl]benzonitrile 36 (F 16618) and 3-(2-chlorophenyl)-1-[4-(4-fluorobenzyl)piperazin-1-yl]propenone 39 (F 16357), obtained after optimization. Both compounds are able to inhibit SFLLR-induced human platelet aggregation and display antithrombotic activity in an arteriovenous shunt model in the rat after iv or oral administration. Furthermore, these compounds are devoid of bleeding side effects often observed with other types of antiplatelet drugs, which constitutes a promising advantage for this new class of antithrombotic agents.

  15. Novel spiropyrazolone antitumor scaffold with potent activity: Design, synthesis and structure-activity relationship.

    PubMed

    Wu, Shanchao; Li, Yu; Xu, Guixia; Chen, Shuqiang; Zhang, Yongqiang; Liu, Na; Dong, Guoqiang; Miao, Chaoyu; Su, Hua; Zhang, Wannian; Sheng, Chunquan

    2016-06-10

    Phenotypic screening of high quality compound library is an effective strategy to discover novel bioactive molecules. Previously, we developed the divergent organocatalytic cascade approach to efficiently construct a focused library with scaffold diversity and successfully identified a novel spiropyrazolone antitumor scaffold. Herein, a series of spiropyrazolone derivatives were designed, synthesized and assayed. Most of them showed good in vitro antitumor activity with a broad spectrum. Preliminary structure-activity relationship for the substitutions and the stereo configuration were obtained. Compound 5k showed good antitumor activity and could effectively induce cancer cell apoptosis, which represents a good starting point for the development of novel antitumor agents. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  16. Delta- and gamma-tocotrienol isomers are potent in inhibiting inflammation and endothelial activation in stimulated human endothelial cells

    PubMed Central

    Muid, Suhaila; Froemming, Gabriele R. Anisah; Rahman, Thuhairah; Ali, A. Manaf; Nawawi, Hapizah M.

    2016-01-01

    Background Tocotrienols (TCTs) are more potent antioxidants than α-tocopherol (TOC). However, the effectiveness and mechanism of the action of TCT isomers as anti-atherosclerotic agents in stimulated human endothelial cells under inflammatory conditions are not well established. Aims 1) To compare the effects of different TCT isomers on inflammation, endothelial activation, and endothelial nitric oxide synthase (eNOS). 2) To identify the two most potent TCT isomers in stimulated human endothelial cells. 3) To investigate the effects of TCT isomers on NFκB activation, and protein and gene expression levels in stimulated human endothelial cells. Methods Human umbilical vein endothelial cells were incubated with various concentrations of TCT isomers or α-TOC (0.3–10 µM), together with lipopolysaccharides for 16 h. Supernatant cells were collected and measured for protein and gene expression of cytokines (interleukin-6, or IL-6; tumor necrosis factor-alpha, or TNF-α), adhesion molecules (intercellular cell adhesion molecule-1, or ICAM-1; vascular cell adhesion molecule-1, or VCAM-1; and e-selectin), eNOS, and NFκB. Results δ-TCT is the most potent TCT isomer in the inhibition of IL-6, ICAM-1, VCAM-1, and NFκB, and it is the second potent in inhibiting e-selectin and eNOS. γ-TCT isomer is the most potent isomer in inhibiting e-selectin and eNOS, and it is the second most potent in inhibiting is IL-6, VCAM-1, and NFκB. For ICAM-1 protein expression, the most potent is δ-TCT followed by α-TCT. α- and β-TCT inhibit IL-6 at the highest concentration (10 µM) but enhance IL-6 at lower concentrations. γ-TCT markedly increases eNOS expression by 8–11-fold at higher concentrations (5–10 µM) but exhibits neutral effects at lower concentrations. Conclusion δ- and γ-TCT are the two most potent TCT isomers in terms of the inhibition of inflammation and endothelial activation whilst enhancing eNOS, possibly mediated via the NFκB pathway. Hence, there is a

  17. Novel Bacterial Topoisomerase Inhibitors with Potent Broad-Spectrum Activity against Drug-Resistant Bacteria.

    PubMed

    Charrier, Cédric; Salisbury, Anne-Marie; Savage, Victoria J; Duffy, Thomas; Moyo, Emmanuel; Chaffer-Malam, Nathan; Ooi, Nicola; Newman, Rebecca; Cheung, Jonathan; Metzger, Richard; McGarry, David; Pichowicz, Mark; Sigerson, Ralph; Cooper, Ian R; Nelson, Gary; Butler, Hayley S; Craighead, Mark; Ratcliffe, Andrew J; Best, Stuart A; Stokes, Neil R

    2017-05-01

    The novel bacterial topoisomerase inhibitor class is an investigational type of antibacterial inhibitor of DNA gyrase and topoisomerase IV that does not have cross-resistance with the quinolones. Here, we report the evaluation of the in vitro properties of a new series of this type of small molecule. Exemplar compounds selectively and potently inhibited the catalytic activities of Escherichia coli DNA gyrase and topoisomerase IV but did not block the DNA breakage-reunion step. Compounds showed broad-spectrum inhibitory activity against a wide range of Gram-positive and Gram-negative pathogens, including biodefence microorganisms and Mycobacterium tuberculosis No cross-resistance with fluoroquinolone-resistant Staphylococcus aureus and E. coli isolates was observed. Measured MIC90 values were 4 and 8 μg/ml against a panel of contemporary multidrug-resistant isolates of Acinetobacter baumannii and E. coli, respectively. In addition, representative compounds exhibited greater antibacterial potency than the quinolones against obligate anaerobic species. Spontaneous mutation rates were low, with frequencies of resistance typically <10(-8) against E. coli and A. baumannii at concentrations equivalent to 4-fold the MIC. Compound-resistant E. coli mutants that were isolated following serial passage were characterized by whole-genome sequencing and carried a single Arg38Leu amino acid substitution in the GyrA subunit of DNA gyrase. Preliminary in vitro safety data indicate that the series shows a promising therapeutic index and potential for low human ether-a-go-go-related gene (hERG) inhibition (50% inhibitory concentration [IC50], >100 μM). In summary, the compounds' distinct mechanism of action relative to the fluoroquinolones, whole-cell potency, low potential for resistance development, and favorable in vitro safety profile warrant their continued investigation as potential broad-spectrum antibacterial agents. Copyright © 2017 American Society for Microbiology.

  18. Cissampelos pareira Linn: Natural Source of Potent Antiviral Activity against All Four Dengue Virus Serotypes

    PubMed Central

    Sood, Ruchi; Raut, Rajendra; Tyagi, Poornima; Pareek, Pawan Kumar; Barman, Tarani Kanta; Singhal, Smita; Shirumalla, Raj Kumar; Kanoje, Vijay; Subbarayan, Ramesh; Rajerethinam, Ravisankar; Sharma, Navin; Kanaujia, Anil; Shukla, Gyanesh; Gupta, Y. K.; Katiyar, Chandra K.; Bhatnagar, Pradip K.; Upadhyay, Dilip J.; Swaminathan, Sathyamangalam; Khanna, Navin

    2015-01-01

    Background Dengue, a mosquito-borne viral disease, poses a significant global public health risk. In tropical countries such as India where periodic dengue outbreaks can be correlated to the high prevalence of the mosquito vector, circulation of all four dengue viruses (DENVs) and the high population density, a drug for dengue is being increasingly recognized as an unmet public health need. Methodology/Principal findings Using the knowledge of traditional Indian medicine, Ayurveda, we developed a systematic bioassay-guided screening approach to explore the indigenous herbal bio-resource to identify plants with pan-DENV inhibitory activity. Our results show that the alcoholic extract of Cissampelos pariera Linn (Cipa extract) was a potent inhibitor of all four DENVs in cell-based assays, assessed in terms of viral NS1 antigen secretion using ELISA, as well as viral replication, based on plaque assays. Virus yield reduction assays showed that Cipa extract could decrease viral titers by an order of magnitude. The extract conferred statistically significant protection against DENV infection using the AG129 mouse model. A preliminary evaluation of the clinical relevance of Cipa extract showed that it had no adverse effects on platelet counts and RBC viability. In addition to inherent antipyretic activity in Wistar rats, it possessed the ability to down-regulate the production of TNF-α, a cytokine implicated in severe dengue disease. Importantly, it showed no evidence of toxicity in Wistar rats, when administered at doses as high as 2g/Kg body weight for up to 1 week. Conclusions/Significance Our findings above, taken in the context of the human safety of Cipa, based on its use in Indian traditional medicine, warrant further work to explore Cipa as a source for the development of an inexpensive herbal formulation for dengue therapy. This may be of practical relevance to a dengue-endemic resource-poor country such as India. PMID:26709822

  19. Systemically active human opiorphin is a potent yet non-addictive analgesic without drug tolerance effects.

    PubMed

    Rougeot, C; Robert, F; Menz, L; Bisson, J-F; Messaoudi, M

    2010-08-01

    Human opiorphin QRFSR-peptide protects enkephalins from degradation by human neutral endopeptidase (hNEP) and aminopeptidase-N (hAP-N) and inhibits pain perception in a behavioral model of mechanical acute pain (1). Here, using two other pain rat models, the tail-flick and the formalin tests, we assess the potency and duration of the antinociceptive action of opiorphin with reference to morphine. The occurrence of adverse effects with emphasis on the side-effect profile at equi-analgesic doses was compared. We demonstrate that opiorphin elicits minimal adverse morphine-associated effects, at doses (1-2 mg/kg, i.v.) that produce a comparable analgesic potency in both spinally controlled thermal-induced acute and peripheral chemical-induced tonic nociception. The analgesic response induced by opiorphin in the formalin-induced pain model preferentially requires activation of endogenous mu-opioid pathways. However, in contrast to exogenous mu-opioid agonists such as morphine, opiorphin, does not develop significant abuse liability or antinociceptive drug tolerance after subchronic treatment. In addition, anti-peristaltism was not observed. We conclude that opiorphin, by inhibiting the destruction of endogenous enkephalins, which are released according to the painful stimulus, activates restricted opioid pathways specifically involved in pain control, thus contributing to a greater balance between analgesia and side-effects than found with morphine. Therefore, opiorphin could give rise to new analgesics endowed with potencies similar to morphine but with fewer adverse effects than opioid agonists. Its chemical optimization, to generate functional derivatives endowed with better bioavailability properties than the native peptide, could lead to a potent class of physiological type analgesics.

  20. Identification of a potent synthetic FXR agonist with an unexpected mode of binding and activation

    SciTech Connect

    Soisson, Stephen M.; Parthasarathy, Gopalakrishnan; Adams, Alan D.; Sahoo, Soumya; Sitlani, Ayesha; Sparrow, Carl; Cui, Jisong; Becker, Joseph W.

    2008-07-08

    The farnesoid X receptor (FXR), a member of the nuclear hormone receptor family, plays important roles in the regulation of bile acid and cholesterol homeostasis, glucose metabolism, and insulin sensitivity. There is intense interest in understanding the mechanisms of FXR regulation and in developing pharmaceutically suitable synthetic FXR ligands that might be used to treat metabolic syndrome. We report here the identification of a potent FXR agonist (MFA-1) and the elucidation of the structure of this ligand in ternary complex with the human receptor and a coactivator peptide fragment using x-ray crystallography at 1.9-{angstrom} resolution. The steroid ring system of MFA-1 binds with its D ring-facing helix 12 (AF-2) in a manner reminiscent of hormone binding to classical steroid hormone receptors and the reverse of the pose adopted by naturally occurring bile acids when bound to FXR. This binding mode appears to be driven by the presence of a carboxylate on MFA-1 that is situated to make a salt-bridge interaction with an arginine residue in the FXR-binding pocket that is normally used to neutralize bound bile acids. Receptor activation by MFA-1 differs from that by bile acids in that it relies on direct interactions between the ligand and residues in helices 11 and 12 and only indirectly involves a protonated histidine that is part of the activation trigger. The structure of the FXR:MFA-1 complex differs significantly from that of the complex with a structurally distinct agonist, fexaramine, highlighting the inherent plasticity of the receptor.

  1. Potent anticancer activity of photo-activated oxo-bridged diiron(III) complexes.

    PubMed

    Chanu, S Binita; Banerjee, Samya; Roy, Mithun

    2017-01-05

    Cancer-specific anticancer drugs are still an elusive goal. Using light as the temporal control to generate cytotoxic species from photo-activated prodrug in the presence or absence of molecular oxygen has shown potential application targeted chemotherapy as in photodynamic therapy (PDT). In the present work we explored the chemistry of several photo-active (μ-oxo)diiron(III) complexes of the following formulation [{Fe(μ-O) (L-his)(B)}2](ClO4)2 (1a-1c), [Fe2(μ-O)(H2O)2B4](ClO4)4 (2b, 2c) and [Fe2(μ-O)(μ-O2CMe)B4](ClO4)3 (3b, 3c), L-his = l-histidine, B is 2,2'-bipyridine, 1,10-phenanthroline (phen) and dipyrido[3,2-d:2',3'-f]quinoxaline (dpq) complexes for tumor-specific anticancer activity. Facile redox chemistry and photochemical aspects of the complexes prompted us to investigate the cytotoxic as well as the photo-activated cytotoxic properties of the complexes to the cancer cells. In the present investigation we explored the cancer-specific condition of excess concentration of H2O2 for our approach to targeted chemotherapy. Cytotoxic effect of the complexes to the cancer cells was found to be significantly higher than in normal cells indicating tumor-specific anticancer activity of the complexes. Cytotoxic effect was even more pronounced when the cancer cells treated with the complexes were exposed to the visible light (400-700 nm). There was >12 fold increase in cytotoxicity of the photoactivated complexes in cancer cells (MCF-7) in comparison to the normal cells (MCF-10a). We have defined a factor viz. cancer cell specificity factor (f) describing the targeted photochemotherapeutic effect of the complexes at their specific concentration. The factor (f) > 1 indicated the cancer cell specificity of the complexes, while f > 2.5 for the complexes under the visible light exposure suggested photodynamic effect. DCFDA assay indicated the presence of excess of ROS in the treated HeLa cells. ROS concentration was found to increase even more on visible

  2. Pyrazole compound BPR1P0034 with potent and selective anti-influenza virus activity

    PubMed Central

    2010-01-01

    the virus during viral uncoating or viral RNA importation into the nucleus. Conclusions To the best of our knowledge, BPR1P0034 is the first pyrazole-based anti-influenza compound ever identified and characterized from high throughput screening to show potent (sub-μM) antiviral activity. We conclude that BPR1P0034 has potential antiviral activity, which offers an opportunity for the development of a new anti-influenza virus agent. PMID:20178582

  3. Synthesis, crystal structure, structure-activity relationships, and antiviral activity of a potent SARS coronavirus 3CL protease inhibitor.

    PubMed

    Yang, Syaulan; Chen, Shu-Jen; Hsu, Min-Feng; Wu, Jen-Dar; Tseng, Chien-Te K; Liu, Yu-Fan; Chen, Hua-Chien; Kuo, Chun-Wei; Wu, Chi-Shen; Chang, Li-Wen; Chen, Wen-Chang; Liao, Shao-Ying; Chang, Teng-Yuan; Hung, Hsin-Hui; Shr, Hui-Lin; Liu, Cheng-Yuan; Huang, Yu-An; Chang, Ling-Yin; Hsu, Jen-Chi; Peters, Clarence J; Wang, Andrew H-J; Hsu, Ming-Chu

    2006-08-10

    A potent SARS coronavirus (CoV) 3CL protease inhibitor (TG-0205221, Ki = 53 nM) has been developed. TG-0205221 showed remarkable activity against SARS CoV and human coronavirus (HCoV) 229E replications by reducing the viral titer by 4.7 log (at 5 microM) for SARS CoV and 5.2 log (at 1.25 microM) for HCoV 229E. The crystal structure of TG-0205221 (resolution = 1.93 A) has revealed a unique binding mode comprising a covalent bond, hydrogen bonds, and numerous hydrophobic interactions. Structural comparisons between TG-0205221 and a natural peptide substrate were also discussed. This information may be applied toward the design of other 3CL protease inhibitors.

  4. The Investigational Fungal Cyp51 Inhibitor VT-1129 Demonstrates Potent In Vitro Activity against Cryptococcus neoformans and Cryptococcus gattii

    PubMed Central

    Lockhart, Shawn R.; Fothergill, Annette W.; Iqbal, Naureen; Bolden, Carol B.; Grossman, Nina T.; Garvey, Edward P.; Brand, Stephen R.; Hoekstra, William J.; Schotzinger, Robert J.; Ottinger, Elizabeth; Patterson, Thomas F.

    2016-01-01

    The in vitro activities of the novel fungal Cyp51 inhibitor VT-1129 were evaluated against a large panel of Cryptococcus neoformans and Cryptococcus gattii isolates. VT-1129 demonstrated potent activities against both Cryptococcus species as demonstrated by low MIC50 and MIC90 values. For C. gattii, the in vitro potency was maintained against all genotypes. In addition, significantly lower geometric mean MICs were observed for VT-1129 than for fluconazole against C. neoformans, including isolates with reduced fluconazole susceptibility. PMID:26787697

  5. Abietane-Type Diterpenoid Amides with Highly Potent and Selective Activity against Leishmania donovani and Trypanosoma cruzi.

    PubMed

    Pirttimaa, Minni; Nasereddin, Abedelmajeed; Kopelyanskiy, Dmitry; Kaiser, Marcel; Yli-Kauhaluoma, Jari; Oksman-Caldentey, Kirsi-Marja; Brun, Reto; Jaffe, Charles L; Moreira, Vânia M; Alakurtti, Sami

    2016-02-26

    Dehydroabietylamine (1) was used as a starting material to synthesize a small library of dehydroabietyl amides by simple and facile methods, and their activities against two disease-causing trypanosomatids, namely, Leishmania donovani and Trypanosoma cruzi, were assayed. The most potent compound, 10, an amide of dehydroabietylamine and acrylic acid, was found to be highly potent against these parasites, displaying an IC50 value of 0.37 μM against L. donovani axenic amastigotes and an outstanding selectivity index of 63. Moreover, compound 10 fully inhibited the growth of intracellular amastigotes in Leishmania donovani-infected human macrophages with a low IC50 value of 0.06 μM. This compound was also highly effective against T. cruzi amastigotes residing in L6 cells with an IC50 value of 0.6 μM and high selectivity index of 58, being 3.5 times more potent than the reference compound benznidazole. The potent activity of this compound and its relatively low cytotoxicity make it attractive for further development in pursuit of better drugs for patients suffering from leishmaniasis and Chagas disease.

  6. N-naphthoyl-β-naltrexamine (NNTA), a highly selective and potent activator of μ/κ-opioid heteromers

    PubMed Central

    Yekkirala, Ajay S.; Lunzer, Mary M.; McCurdy, Christopher R.; Powers, Michael D.; Kalyuzhny, Alexander E.; Roerig, Sandra C.; Portoghese, Philip S.

    2011-01-01

    Numerous G protein-coupled receptors (GPCRs) have been shown to form heteromeric receptors in cell-based assays. Among the many heteromers reported in the opioid receptor family are μ/κ, κ/δ, and μ/δ. However, the in vivo physiological and behavioral relevance for the proposed heteromers have not yet been established. Here we report a unique example of a ligand, N-naphthoyl-β-naltrexamine (NNTA) that selectively activates heteromeric μ/κ-opioid receptors in HEK-293 cells and induces potent antinociception in mice. NNTA was an exceptionally potent agonist in cells expressing μ/κ-opioid receptors. Intriguingly, it was found to be a potent antagonist in cells expressing only μ-receptors. In the mouse tail-flick assay, intrathecal (i.t.) NNTA produced antinociception that was ~100-fold greater than by intracerebroventricular (i.c.v.) administration. The κ-antagonist, norBNI, decreased the i.t. potency, and the activity was virtually abolished in μ-opioid receptor knockout mice. No tolerance was induced i.t., but marginal tolerance (3-fold) was observed via the i.c.v. route. Moreover, NNTA produced neither significant physical dependence nor place preference in the ED50 dose range. Taken together, this work provides an important pharmacologic tool for investigating the in vivo functional relevance of heteromeric μ/κ-opioid receptors and suggests an approach to potent analgesics with fewer deleterious side effects. PMID:21385944

  7. Glycodermorphins: opioid peptides with potent and prolonged analgesic activity and enhanced blood-brain barrier penetration.

    PubMed

    Negri, L; Lattanzi, R; Tabacco, F; Scolaro, B; Rocchi, R

    1998-08-01

    1. In order to improve the in vivo stability of the opioid peptide dermorphin we synthesized O-betaglucosylated analogs ([Ser7-O-betaGlc]dermorphin and [Ser7-O-betaGlc(Ac)4]-dermorphin) and C-alphagalactosylated analogs ([Ala7-C-alphaGal]dermorphin and [Ala7-C-alphaGal(Ac)4]-dermorphin). 2. O- and C-glycosylation of dermorphin halved the peptide affinity for brain mu-opioid receptors and the biological potency in guinea-pig ileum assay (GPI). Despite their lower opioid receptor affinity, when administered intracerebroventricularly (i.c.v., 8-40 pmol) and subcutaneously (s.c., 0.5-3 micromol kg(-1)) in rats, glycosylated analogs were two times more potent than dermorphin in reducing the nociceptive response to radiant heat. Acetylation of sugar hydroxyl groups reduces 5-10 times both biological activity on GPI and mu-receptor affinity, whereas the antinociceptive potency was equal to (i.c.v.) or only two-three times lower (s.c.) than dermorphin potency. 3. Blood-Brain Barrier Permeability Index (BBB-PI) of the glycodermorphins was significantly higher than that of dermorphin, indicating a facilitated entry into the brain: O-beta-linked glucoconiugates are expected to enter CNS by the glucose transporter GLUT-1 of the endothelial barrier. However the calculated BBB-PI for the C-alphagalactoside was about two times higher than that of the O-betaglucoside, excluding the implication of GLUT-1 that is known to be selective for O-beta-links and preferring for the exose glucose. 4. The enhanced brain permeability with the subsequent decrease in peripheral dosage of these opioid peptides did not result in lowering constipation.

  8. Glycodermorphins: opioid peptides with potent and prolonged analgesic activity and enhanced blood-brain barrier penetration

    PubMed Central

    Negri, Lucia; Lattanzi, Roberta; Tabacco, Fabio; Scolaro, Barbara; Rocchi, Raniero

    1998-01-01

    In order to improve the in vivo stability of the opioid peptide dermorphin we synthesized O-βglucosylated analogs ([Ser7-O-βGlc]dermorphin and [Ser7-O-βGlc(Ac)4]-dermorphin) and C-αgalactosylated analogs ([Ala7-C-αGal]dermorphin and [Ala7-C-αGal(Ac)4]-dermorphin).O- and C-glycosylation of dermorphin halved the peptide affinity for brain μ-opioid receptors and the biological potency in guinea-pig ileum assay (GPI). Despite their lower opioid receptor affinity, when administered intracerebroventricularly (i.c.v., 8–40 pmol) and subcutaneously (s.c., 0.5–3 μmol kg−1) in rats, glycosylated analogs were two times more potent than dermorphin in reducing the nociceptive response to radiant heat. Acetylation of sugar hydroxyl groups reduces 5–10 times both biological activity on GPI and μ-receptor affinity, whereas the antinociceptive potency was equal to (i.c.v.) or only two-three times lower (s.c.) than dermorphin potency.Blood-Brain Barrier Permeability Index (BBB-PI) of the glycodermorphins was significantly higher than that of dermorphin, indicating a facilitated entry into the brain: O-β-linked glucoconiugates are expected to enter CNS by the glucose transporter GLUT-1 of the endothelial barrier. However the calculated BBB-PI for the C-αgalactoside was about two times higher than that of the O-βglucoside, excluding the implication of GLUT-1 that is known to be selective for O-β-links and preferring for the exose glucose.The enhanced brain permeability with the subsequent decrease in peripheral dosage of these opioid peptides did not result in lowering constipation. PMID:9723966

  9. Activation of non-sensitizing or low-sensitizing fragrance substances into potent sensitizers - prehaptens and prohaptens.

    PubMed

    Karlberg, Ann-Therese; Börje, Anna; Duus Johansen, Jeanne; Lidén, Carola; Rastogi, Suresh; Roberts, David; Uter, Wolfgang; White, Ian R

    2013-12-01

    Experimental and clinical studies have shown that fragrance substances can act as prehaptens or prohaptens. They form allergens that are more potent than the parent substance by activation outside or in the skin via abiotic (chemical and physical factors) and/or biotic activation, thus, increasing the risk of sensitization. In the present review a series of fragrance substances with well documented abiotic and/or biotic activation are given as indicative and illustrative examples of the general problem. Commonly used fragrance substances, also found in essential oils, autoxidize on contact with air, forming potent sensitizers that can be an important source for contact allergy to fragrances and fragranced products. Some of them can act as prohaptens and be activated in the skin as well. The experimental findings are confirmed in large clinical studies. When substances with structural alerts for acting as prohaptens and/or prehaptens are identified, the possibility of generating new potent allergens should be considered. Predictive testing should include activation steps. Further experimental and clinical research regarding activation of fragrance substances is needed to increase consumer safety. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Discovery of a Potent and Selective BCL-XL Inhibitor with in Vivo Activity.

    PubMed

    Tao, Zhi-Fu; Hasvold, Lisa; Wang, Le; Wang, Xilu; Petros, Andrew M; Park, Chang H; Boghaert, Erwin R; Catron, Nathaniel D; Chen, Jun; Colman, Peter M; Czabotar, Peter E; Deshayes, Kurt; Fairbrother, Wayne J; Flygare, John A; Hymowitz, Sarah G; Jin, Sha; Judge, Russell A; Koehler, Michael F T; Kovar, Peter J; Lessene, Guillaume; Mitten, Michael J; Ndubaku, Chudi O; Nimmer, Paul; Purkey, Hans E; Oleksijew, Anatol; Phillips, Darren C; Sleebs, Brad E; Smith, Brian J; Smith, Morey L; Tahir, Stephen K; Watson, Keith G; Xiao, Yu; Xue, John; Zhang, Haichao; Zobel, Kerry; Rosenberg, Saul H; Tse, Chris; Leverson, Joel D; Elmore, Steven W; Souers, Andrew J

    2014-10-09

    A-1155463, a highly potent and selective BCL-XL inhibitor, was discovered through nuclear magnetic resonance (NMR) fragment screening and structure-based design. This compound is substantially more potent against BCL-XL-dependent cell lines relative to our recently reported inhibitor, WEHI-539, while possessing none of its inherent pharmaceutical liabilities. A-1155463 caused a mechanism-based and reversible thrombocytopenia in mice and inhibited H146 small cell lung cancer xenograft tumor growth in vivo following multiple doses. A-1155463 thus represents an excellent tool molecule for studying BCL-XL biology as well as a productive lead structure for further optimization.

  11. Structure-activity relationship of Garcinia xanthones analogues: Potent Hsp90 inhibitors with cytotoxicity and antiangiogenesis activity.

    PubMed

    Xu, Xiaoli; Wu, Yue; Hu, Mingyang; Li, Xiang; Gu, Congying; You, Qidong; Zhang, Xiaojin

    2016-10-01

    Hsp90 has long been recognized as an attractive and crucial molecular target for cancer therapy. Gambogic acid (GA), the main active compound of Gamboge hanburyi, has been reported as a natural inhibitor of Hsp90. Here, we present the structure-activity relationship of Garcinia xanthones analogues as Hsp90 inhibitors and identify that compound 25, with a simplified skeleton, had an improved inhibitory effect toward Hsp90. Compound 25 inhibited the ATPase activity of Hsp90 with an IC50 value of 3.68±0.18μM. It also exhibited potent antiproliferative activities in some solid tumor cells. In SK-BR-3 cells with high Hsp90 expression, compound 25 induced the degradation of Hsp90 client proteins including Akt and Erk1/2 without causing the heat shock response. Additionally, compound 25 inhibited angiogenesis in HUVEC cells through Hsp90 regulation of the HIF-1α pathway. These results demonstrate that compound 25 as an Hsp90 inhibitor with a new structure could be further studied for the development of tumor therapy. Copyright © 2016. Published by Elsevier Ltd.

  12. Dihydroxyeicosatrienoic acids are potent activators of Ca2+-activated K+ channels in isolated rat coronary arterial myocytes

    PubMed Central

    Lu, Tong; Katakam, Prasad V G; VanRollins, Mike; Weintraub, Neal L; Spector, Arthur A; Lee, Hon-Chi

    2001-01-01

    Dihydroxyeicosatrienoic acids (DHETs), which are metabolites of arachidonic acid (AA) and epoxyeicosatrienoic acids (EETs), have been identified as highly potent endogenous vasodilators, but the mechanisms by which DHETs induce relaxation of vascular smooth muscle are unknown. Using inside-out patch clamp techniques, we examined the effects of DHETs on the large conductance Ca2+-activated K+ (BK) channels in smooth muscle cells from rat small coronary arteries (150–300 μm diameter). 11,12-DHET potently activated BK channels with an EC50 of 1.87 ± 0.57 nm (n = 5). Moreover, the three other regioisomers 5,6-, 8,9- and 14,15-DHET were equipotent with 11,12-DHET in activating BK channels. The efficacy of 11,12-DHET in opening BK channels was much greater than that of its immediate precursor 11,12-EET. In contrast, AA did not significantly affect BK channel activity. The voltage dependence of BK channels was dramatically modulated by 11,12-DHET. With physiological concentrations of cytoplasmic Ca2+ (200 nm), the voltage at which the channel open probability was half-maximal (V1/2) was shifted from a baseline of 115.6 ± 6.5 mV to 95.0 ± 10.1 mV with 5 nm 11,12-DHET, and to 60.0 ± 8.4 mV with 50 nm 11,12-DHET. 11,12-DHET also enhanced the sensitivity of BK channels to Ca2+ but did not activate the channels in the absence of Ca2+. 11,12-DHET (50 nm) reduced the Ca2+ EC50 of BK channels from a baseline of 1.02 ± 0.07 μm to 0.42 ± 0.11 μm. Single channel kinetic analysis indicated that 11,12-DHET did not alter BK channel conductance but did reduce the first latency of BK channel openings in response to a voltage step. 11,12-DHET dose-dependently increased the open dwell times, abbreviated the closed dwell times, and decreased the transition rates from open to closed states. We conclude that DHETs hyperpolarize vascular smooth muscle cells through modulation of the BK channel gating behaviour, and by enhancing the channel sensitivities to Ca2+ and voltage. Hence

  13. Optimization of 2-Anilino 4-Amino Substituted Quinazolines into Potent Antimalarial Agents with Oral in Vivo Activity.

    PubMed

    Gilson, Paul R; Tan, Cyrus; Jarman, Kate E; Lowes, Kym N; Curtis, Joan M; Nguyen, William; Di Rago, Adrian E; Bullen, Hayley E; Prinz, Boris; Duffy, Sandra; Baell, Jonathan B; Hutton, Craig A; Jousset Subroux, Helene; Crabb, Brendan S; Avery, Vicky M; Cowman, Alan F; Sleebs, Brad E

    2017-02-09

    Novel antimalarial therapeutics that target multiple stages of the parasite lifecycle are urgently required to tackle the emerging problem of resistance with current drugs. Here, we describe the optimization of the 2-anilino quinazoline class as antimalarial agents. The class, identified from publicly available antimalarial screening data, was optimized to generate lead compounds that possess potent antimalarial activity against P. falciparum parasites comparable to the known antimalarials, chloroquine and mefloquine. During the optimization process, we defined the functionality necessary for activity and improved in vitro metabolism and solubility. The resultant lead compounds possess potent activity against a multidrug resistant strain of P. falciparum and arrest parasites at the ring phase of the asexual stage and also gametocytogensis. Finally, we show that the lead compounds are orally efficacious in a 4 day murine model of malaria disease burden.

  14. Design, synthesis, and characterization of novel tetrahydropyran-based bacterial topoisomerase inhibitors with potent anti-gram-positive activity.

    PubMed

    Surivet, Jean-Philippe; Zumbrunn, Cornelia; Rueedi, Georg; Hubschwerlen, Christian; Bur, Daniel; Bruyère, Thierry; Locher, Hans; Ritz, Daniel; Keck, Wolfgang; Seiler, Peter; Kohl, Christopher; Gauvin, Jean-Christophe; Mirre, Azely; Kaegi, Verena; Dos Santos, Marina; Gaertner, Mika; Delers, Jonathan; Enderlin-Paput, Michel; Boehme, Maria

    2013-09-26

    There is an urgent need for new antibacterial drugs that are effective against infections caused by multidrug-resistant pathogens. Novel nonfluoroquinolone inhibitors of bacterial type II topoisomerases (DNA gyrase and topoisomerase IV) have the potential to become such drugs because they display potent antibacterial activity and exhibit no target-mediated cross-resistance with fluoroquinolones. Bacterial topoisomerase inhibitors that are built on a tetrahydropyran ring linked to a bicyclic aromatic moiety through a syn-diol linker show potent anti-Gram-positive activity, covering isolates with clinically relevant resistance phenotypes. For instance, analog 49c was found to be a dual DNA gyrase-topoisomerase IV inhibitor, with broad antibacterial activity and low propensity for spontaneous resistance development, but suffered from high hERG K(+) channel block. On the other hand, analog 49e displayed lower hERG K(+) channel block while retaining potent in vitro antibacterial activity and acceptable frequency for resistance development. Furthermore, analog 49e showed moderate clearance in rat and promising in vivo efficacy against Staphylococcus aureus in a murine infection model.

  15. Synthesis and bioevaluation of N,4-diaryl-1,3-thiazole-2-amines as tubulin inhibitors with potent antiproliferative activity

    PubMed Central

    Xu, Jingwen; Wu, Yue; Wang, Yueting; Zuo, Daiying; Guan, Qi; Bao, Kai; Wang, Jian; Wu, Yingliang; Zhang, Weige

    2017-01-01

    A series of N,4-diaryl-1,3-thiazole-2-amines containing three aromatic rings with an amino linker were designed and synthesized as tubulin inhibitors and evaluated for their antiproliferative activity in three human cancer cell lines. Most of the target compounds displayed moderate antiproliferative activity, and N-(2,4-dimethoxyphenyl)-4-(4-methoxyphenyl)-1,3-thiazol-2-amine (10s) was determined to be the most potent compound. Tubulin polymerization and immunostaining experiments revealed that 10s potently inhibited tubulin polymerization and disrupted tubulin microtubule dynamics in a manner similar to CA-4. Moreover, 10s effectively induced SGC-7901 cell cycle arrest at the G2/M phase in both concentration- and time-dependent manners. The molecular docking results revealed that 10s could bind to the colchicine binding site of tubulin. PMID:28333984

  16. Novel seleno- and thio-urea derivatives with potent in vitro activities against several cancer cell lines.

    PubMed

    Alcolea, Verónica; Plano, Daniel; Karelia, Deepkamal N; Palop, Juan Antonio; Amin, Shantu; Sanmartín, Carmen; Sharma, Arun K

    2016-05-04

    A series of novel selenourea derivatives and corresponding thiourea analogs were synthesized and tested against a panel of six human cancer cell lines: melanoma (1205Lu), lung carcinoma (A549), prostatic carcinoma (DU145), colorectal carcinoma (HCT116), pancreatic epithelioid carcinoma (PANC-1) and pancreatic adenocarcinoma (BxPC3). In general, we found that the selenium-containing derivatives were more potent than their isosteric sulfur analogs. Four selenourea derivatives (1e, 1f, 1g and 1i) showed IC50 values below 10 μM in all of tested cell lines at 72 h. On the basis of its potent activity, compound 1g was selected for further biological evaluation in different colon cancer cell lines. Our results indicated that compound 1g induced apoptosis by caspase activation, along with inhibition of anti-apoptotic proteins. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Hypoxia-activated pro-drug TH-302 exhibits potent tumor suppressive activity and cooperates with chemotherapy against osteosarcoma.

    PubMed

    Liapis, Vasilios; Labrinidis, Agatha; Zinonos, Irene; Hay, Shelley; Ponomarev, Vladimir; Panagopoulos, Vasilios; DeNichilo, Mark; Ingman, Wendy; Atkins, Gerald J; Findlay, David M; Zannettino, Andrew C W; Evdokiou, Andreas

    2015-02-01

    Tumor hypoxia is a major cause of treatment failure for a variety of malignancies. However, tumor hypoxia also offers treatment opportunities, exemplified by the development compounds that target hypoxic regions within tumors. TH-302 is a pro-drug created by the conjugation of 2-nitroimidazole to bromo-isophosphoramide (Br-IPM). When TH-302 is delivered to regions of hypoxia, Br-IPM, the DNA cross linking toxin, is released. In this study we assessed the cytotoxic activity of TH-302 against osteosarcoma cells in vitro and evaluated its anticancer efficacy as a single agent, and in combination with doxorubicin, in an orthotopic mouse model of human osteosarcoma (OS). In vitro, TH-302 was potently cytotoxic to osteosarcoma cells selectively under hypoxic conditions, whereas primary normal human osteoblasts were protected. Animals transplanted with OS cells directly into their tibiae and left untreated developed mixed osteolytic/osteosclerotic bone lesions and subsequently developed lung metastases. TH-302 reduced tumor burden in bone and cooperated with doxorubicin to protect bone from osteosarcoma induced bone destruction, while it also reduced lung metastases. TH-302 may therefore be an attractive therapeutic agent with strong activity as a single agent and in combination with chemotherapy against OS. Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.

  18. Identification of a novel multiple kinase inhibitor with potent antiviral activity against influenza virus by reducing viral polymerase activity.

    PubMed

    Sasaki, Yutaka; Kakisaka, Michinori; Chutiwitoonchai, Nopporn; Tajima, Shigeru; Hikono, Hirokazu; Saito, Takehiko; Aida, Yoko

    2014-07-18

    Neuraminidase inhibitors are the only currently available influenza treatment, although resistant viruses to these drugs have already been reported. Thus, new antiviral drugs with novel mechanisms of action are urgently required. In this study, we identified a novel antiviral compound, WV970, through cell-based screening of a 50,000 compound library and subsequent lead optimization. This compound exhibited potent antiviral activity with nanomolar IC50 values against both influenza A and B viruses but not non-influenza RNA viruses. Time-of-addition and indirect immunofluorescence assays indicated that WV970 acted at an early stage of the influenza life cycle, but likely after nuclear entry of viral ribonucleoprotein (vRNP). Further analyses of viral RNA expression and viral polymerase activity indicated that WV970 inhibited vRNP-mediated viral genome replication and transcription. Finally, structure-based virtual screening and comprehensive human kinome screening were used to demonstrate that WV970 acts as a multiple kinase inhibitor, many of which are associated with influenza virus replication. Collectively, these results strongly suggest that WV970 is a promising anti-influenza drug candidate and that several kinases associated with viral replication are promising drug targets.

  19. Acetoxybenzhydrols as highly active and stable analogues of 1'S-1'-acetoxychavicol, a potent antiallergic principal from Alpinia galanga.

    PubMed

    Yasuhara, Tomohisa; Manse, Yoshiaki; Morimoto, Takayuki; Qilong, Wang; Matsuda, Hisashi; Yoshikawa, Masayuki; Muraoka, Osamu

    2009-06-01

    Through SAR studies on 1'S-1'-acetoxychavicol acetate (1) against Type I antiallergic activity by indexing release of beta-hexosaminidase, a marker of antigen-IgE-mediated degranulation in RBL-2H3 cells, more stable and potent analogue, 4-(methoxycarbonyloxyphenylmethyl)phenyl acetate (16), has been developed. The compound 16 also strongly inhibited the antigen-IgE-mediated TNF-alpha and IL-4 production.

  20. The Investigational Fungal Cyp51 Inhibitor VT-1129 Demonstrates Potent In Vitro Activity against Cryptococcus neoformans and Cryptococcus gattii.

    PubMed

    Lockhart, Shawn R; Fothergill, Annette W; Iqbal, Naureen; Bolden, Carol B; Grossman, Nina T; Garvey, Edward P; Brand, Stephen R; Hoekstra, William J; Schotzinger, Robert J; Ottinger, Elizabeth; Patterson, Thomas F; Wiederhold, Nathan P

    2016-04-01

    Thein vitroactivities of the novel fungal Cyp51 inhibitor VT-1129 were evaluated against a large panel ofCryptococcus neoformansandCryptococcus gattiiisolates. VT-1129 demonstrated potent activities against bothCryptococcusspecies as demonstrated by low MIC50and MIC90values. ForC. gattii, thein vitropotency was maintained against all genotypes. In addition, significantly lower geometric mean MICs were observed for VT-1129 than for fluconazole againstC. neoformans, including isolates with reduced fluconazole susceptibility.

  1. Larvicidal activity of Cymbopogon citratus (DC) Stapf. and Croton macrostachyus Del. against Anopheles arabiensis Patton, a potent malaria vector.

    PubMed

    Karunamoorthi, K; Ilango, K

    2010-01-01

    Methanol leaf extracts of two Ethiopian traditional medicinal plants viz., Lomisar [vernacular name (local native language, Amharic); Cymbopogon citratus (DC) Stapf. (Poaceae)] and Bisana [vernacular name (local native language, Amharic); Croton macrostachyus Del. (Euphorbiaceae)] were screened for larvicidal activity against late third instar larvae of Anopheles arabiensis Patton, a potent malaria vector in Ethiopia. The larval mortality was observed 24 h of post treatment. Both plant extracts demonstrated varying degrees of larvicidal activity against Anopheles arabiensis. Cymbopogon citratus extract has exhibited potent larvicidal activity than Croton macrostachyus at lower concentrations. The LC50 and LC90 values of Cymbopogon citratus were 74.02 and 158.20 ppm, respectively. From this data, a chi-square value 2.760 is significant at the P < 0.05 level. While, the LC50 and LC90 values of Croton macrostachyus were 89.25 and 224.98 ppm, respectively and the chi-square value 1.035 is significant at the P < 0.05 level. The present investigation establishes that these plant extracts could serve as potent mosquito larvicidal agents against Anopheles arabiensis. However, their mode of actions and larvicidal efficiency under the field conditions should be scrutinized and determined in the near future.

  2. MIT(1), a black mamba toxin with a new and highly potent activity on intestinal contraction.

    PubMed

    Schweitz, H; Pacaud, P; Diochot, S; Moinier, D; Lazdunski, M

    1999-11-19

    Mamba intestinal toxin (MIT(1)) isolated from Dendroaspis polylepis venom is a 81 amino acid polypeptide cross-linked by five disulphide bridges. MIT(1) has a very potent action on guinea-pig intestinal contractility. MIT(1) (1 nM) potently contracts longitudinal ileal muscle and distal colon, and this contraction is equivalent to that of 40 mM K(+). Conversely MIT(1) relaxes proximal colon again as potently as 40 mM K(+). The MIT(1)-induced effects are antagonised by tetrodotoxin (1 microM) in proximal and distal colon but not in longitudinal ileum. The MIT(1)-induced relaxation of the proximal colon is reversibly inhibited by the NO synthase inhibitor L-NAME (200 microM). (125)I-labelled MIT(1) binds with a very high affinity to both ileum and brain membranes (K(d)=1.3 pM and 0.9 pM, and B(max)=30 fmol/mg and 26 fmol/mg, respectively). MIT(1) is a very highly selective toxin for a receptor present both in the CNS and in the smooth muscle and which might be an as yet unidentified K(+) channel.

  3. New pyrrole derivatives with potent tubulin polymerization inhibiting activity as anticancer agents including hedgehog-dependent cancer.

    PubMed

    La Regina, Giuseppe; Bai, Ruoli; Coluccia, Antonio; Famiglini, Valeria; Pelliccia, Sveva; Passacantilli, Sara; Mazzoccoli, Carmela; Ruggieri, Vitalba; Sisinni, Lorenza; Bolognesi, Alessio; Rensen, Whilelmina Maria; Miele, Andrea; Nalli, Marianna; Alfonsi, Romina; Di Marcotullio, Lucia; Gulino, Alberto; Brancale, Andrea; Novellino, Ettore; Dondio, Giulio; Vultaggio, Stefania; Varasi, Mario; Mercurio, Ciro; Hamel, Ernest; Lavia, Patrizia; Silvestri, Romano

    2014-08-14

    We synthesized 3-aroyl-1-arylpyrrole (ARAP) derivatives as potential anticancer agents having different substituents at the pendant 1-phenyl ring. Both the 1-phenyl ring and 3-(3,4,5-trimethoxyphenyl)carbonyl moieties were mandatory to achieve potent inhibition of tubulin polymerization, binding of colchicine to tubulin, and cancer cell growth. ARAP 22 showed strong inhibition of the P-glycoprotein-overexpressing NCI-ADR-RES and Messa/Dx5MDR cell lines. Compounds 22 and 27 suppressed in vitro the Hedgehog signaling pathway, strongly reducing luciferase activity in SAG treated NIH3T3 Shh-Light II cells, and inhibited the growth of medulloblastoma D283 cells at nanomolar concentrations. ARAPs 22 and 27 represent a new potent class of tubulin polymerization and cancer cell growth inhibitors with the potential to inhibit the Hedgehog signaling pathway.

  4. Design, synthesis, and structure-activity relationship studies of novel 3-alkylindole derivatives as selective and highly potent myeloperoxidase inhibitors.

    PubMed

    Soubhye, Jalal; Aldib, Iyas; Elfving, Betina; Gelbcke, Michel; Furtmüller, Paul G; Podrecca, Manuel; Conotte, Raphaël; Colet, Jean-Marie; Rousseau, Alexandre; Reye, Florence; Sarakbi, Ahmad; Vanhaeverbeek, Michel; Kauffmann, Jean-Michel; Obinger, Christian; Nève, Jean; Prévost, Martine; Zouaoui Boudjeltia, Karim; Dufrasne, Francois; Van Antwerpen, Pierre

    2013-05-23

    Due to its production of potent antimicrobial oxidants including hypochlorous acid, human myeloperoxidase (MPO) plays a critical role in innate immunity and inflammatory diseases. Thus MPO is an attractive target in drug design. (Aminoalkyl)fluoroindole derivatives were detected to be very potent MPO inhibitors; however, they also promote inhibition of the serotonin reuptake transporter (SERT) at the same concentration range. Via structure-based drug design, a new series of MPO inhibitors derived from 3-alkylindole were synthesized and their effects were assessed on MPO-mediated taurine chlorination and low-density lipoprotein oxidation as well as on inhibition of SERT. The fluoroindole compound with three carbons in the side chain and one amide group exhibited a selectivity index of 35 (Ki/IC50) with high inhibition of MPO activity (IC50 = 18 nM), whereas its effect on SERT was in the micromolar range. Structure-function relationships, mechanism of action, and safety of the molecule are discussed.

  5. Anthelmintic properties of traditional African and Caribbean medicinal plants: identification of extracts with potent activity against Ascaris suum in vitro

    PubMed Central

    Williams, Andrew R.; Soelberg, Jens; Jäger, Anna K.

    2016-01-01

    Ascariasis affects more than 1 billion people worldwide, mainly in developing countries, causing substantial morbidity. Current treatments for Ascaris infection are based on mass drug administration (MDA) with synthetic anthelmintic drugs such as albendazole, however continual re-infection and the threat of drug resistance mean that complementary treatment options would be highly valuable. Here, we screened ethanolic extracts from 29 medicinal plants used in Africa (Ghana) and the Caribbean (US Virgin Islands) for in vitro anthelmintic properties against Ascaris suum, a swine parasite that is very closely related to the human A. lumbricoides. A wide variety of activities were seen in the extracts, from negligible to potent. Extracts from Clausena anisata, Zanthoxylum zanthoxyloides and Punica granatum were identified as the most potent with EC50 values of 74, 97 and 164 μg/mL, respectively. Our results encourage further investigation of their use as complementary treatment options for ascariasis, alongside MDA. PMID:27301442

  6. Structure-activity relationship investigation for benzonaphthyridinone derivatives as novel potent Bruton's tyrosine kinase (BTK) irreversible inhibitors.

    PubMed

    Wang, Beilei; Deng, Yuanxin; Chen, Yongfei; Yu, Kailin; Wang, Aoli; Liang, Qianmao; Wang, Wei; Chen, Cheng; Wu, Hong; Hu, Chen; Miao, Weili; Hur, Wooyoung; Wang, Wenchao; Hu, Zhenquan; Weisberg, Ellen L; Wang, Jinhua; Ren, Tao; Wang, Yinsheng; Gray, Nathanael S; Liu, Qingsong; Liu, Jing

    2017-09-08

    Through a structure-based drug design approach, a tricyclic benzonaphthyridinone pharmacophore was used as a starting point for carrying out detailed medicinal structure-activity relationhip (SAR) studies geared toward characterization of a panel of proposed BTK inhibitors, including 6 (QL-X-138), 7 (BMX-IN-1) and 8 (QL47). These studies led to the discovery of the novel potent irreversible BTK inhibitor, compound 18 (CHMFL-BTK-11). Kinetic analysis of compound 18 revealed an irreversible binding efficacy (kinact/Ki) of 0.01 μM(-1)s(-1). Compound 18 potently inhibited BTK kinase Y223 auto-phosphorylation (EC50 < 100 nM), arrested cell cycle in G0/G1 phase, and induced apoptosis in Ramos, MOLM13 and Pfeiffer cells. We believe these features would make 18 a good pharmacological tool for studying BTK-related pathologies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. New Pyrrole Derivatives with Potent Tubulin Polymerization Inhibiting Activity As Anticancer Agents Including Hedgehog-Dependent Cancer

    PubMed Central

    La Regina, Giuseppe; Bai, Ruoli; Coluccia, Antonio; Famiglini, Valeria; Pelliccia, Sveva; Passacantilli, Sara; Mazzoccoli, Carmela; Ruggieri, Vitalba; Sisinni, Lorenza; Bolognesi, Alessio; Rensen, Whilelmina Maria; Miele, Andrea; Nalli, Marianna; Alfonsi, Romina; Di Marcotullio, Lucia; Gulino, Alberto; Brancale, Andrea; Novellino, Ettore; Dondio, Giulio; Vultaggio, Stefania; Varasi, Mario; Mercurio, Ciro; Hamel, Ernest; Lavia, Patrizia; Silvestri, Romano

    2014-01-01

    We synthesized 3-aroyl-1-arylpyrrole (ARAP) derivatives as potential anticancer agents having different substituents at the pendant 1-phenyl ring. Both the 1-phenyl ring and 3-(3,4,5-trimethoxyphenyl)carbonyl moieties were mandatory to achieve potent inhibition of tubulin polymerization, binding of colchicine to tubulin, and cancer cell growth. ARAP 22 showed strong inhibition of the P-glycoprotein-overexpressing NCI-ADR-RES and Messa/Dx5MDR cell lines. Compounds 22 and 27 suppressed in vitro the Hedgehog signaling pathway, strongly reducing luciferase activity in SAG treated NIH3T3 Shh-Light II cells, and inhibited the growth of medulloblastoma D283 cells at nanomolar concentrations. ARAPs 22 and 27 represent a new potent class of tubulin polymerization and cancer cell growth inhibitors with the potential to inhibit the Hedgehog signaling pathway. PMID:25025991

  8. 4-Norleucine, 7-D-phenylalanine-alpha-melanocyte-stimulating hormone: a highly potent alpha-melanotropin with ultralong biological activity.

    PubMed Central

    Sawyer, T K; Sanfilippo, P J; Hruby, V J; Engel, M H; Heward, C B; Burnett, J B; Hadley, M E

    1980-01-01

    alpha-Melanocyte-stimulating hormone (alpha-MSH) reversibly darkens frog skins by stimulating melanosome movement (dispersion) within melanophores. Heat-alkali treatment of alpha-MSH results in prolonged biological activity of the hormone. Quantitative gas chromatographic analysis of the hydrolyzed heat-alkali-treated peptide revealed partial racemization particularly at the 4(methionine) and 7(phenylalanine) positions. [Nle4]-alpha-MSH, a synthetic analogue of alpha-MSH, reversibly darkens frog skins and also exhibits prolonged activity after heat-alkali treatment. Synthesis of [Nle4, D-Phe7]-alpha-MSH provided an analogue with prolonged biological activity identical to that observed with heat-alkali-treated alpha-MSH or [Nle4]-alpha-MSH. [Nle4, D-Phe7]-alpha-MSH was resistant to enzymatic degradation by serum enzymes. In addition, this peptide exhibited dramatically increased biological activity as determined by frog skin bioassay, activation of mouse melanoma adenylate cyclase, and stimulation of mouse melanoma cell tyrosinase activity. This Nle4, D-Phe7 synthetic analogue of alpha-MSH is a very porent melanotropin, 26 times as potent as alpha-MSH in the adenylate cyclase assay. The resistance of the peptide to enzymatic degradation and its extraordinarily potent and prolonged biological activity should make this analogue of alpha-MSH an important molecular probe for studying the melanotropin receptors of both normal and abnormal (melanoma) melanocytes. PMID:6777774

  9. Influence of ethylene-oxy spacer group on the activity of linezolid: synthesis of potent antibacterials possessing a thiocarbonyl group.

    PubMed

    Selvakumar, N; Raheem, Mohammed A; Khera, Manoj Kumar; Rajale, Trideep V; Kumar, Magadi Sitaram; Kandepu, Sreenivas; Das, Jagattaran; Rajagopalan, R; Iqbal, Javed; Trehan, Sanjay

    2003-12-01

    The influence of an ethylene-oxy spacer element between the heterocycle and the aromatic ring in linezolid is reported. The introduction of such spacer group generated compounds with inferior antibacterial activity. However, the conversion of the acetamide group present in the linezolid analogues to either thiocarbamate or thioacetamide functionality restored the activity. The synthesis of linezolid analogues possessing the ethylene-oxy spacer group along with SAR studies with different heterocycles and preparation of some thiocarbonyl compounds possessing potent antibacterial property are presented.

  10. Identification of a novel multiple kinase inhibitor with potent antiviral activity against influenza virus by reducing viral polymerase activity

    SciTech Connect

    Sasaki, Yutaka; Kakisaka, Michinori; Chutiwitoonchai, Nopporn; Tajima, Shigeru; Hikono, Hirokazu; Saito, Takehiko; Aida, Yoko

    2014-07-18

    Highlights: • Screening of 50,000 compounds and subsequent lead optimization identified WV970. • WV970 has antiviral effects against influenza A, B and highly pathogenic viral strains. • WV970 inhibits viral genome replication and transcription. • A target database search suggests that WV970 may bind to a number of kinases. • KINOMEscan screening revealed that WV970 has inhibitory effects on 15 kinases. - Abstract: Neuraminidase inhibitors are the only currently available influenza treatment, although resistant viruses to these drugs have already been reported. Thus, new antiviral drugs with novel mechanisms of action are urgently required. In this study, we identified a novel antiviral compound, WV970, through cell-based screening of a 50,000 compound library and subsequent lead optimization. This compound exhibited potent antiviral activity with nanomolar IC{sub 50} values against both influenza A and B viruses but not non-influenza RNA viruses. Time-of-addition and indirect immunofluorescence assays indicated that WV970 acted at an early stage of the influenza life cycle, but likely after nuclear entry of viral ribonucleoprotein (vRNP). Further analyses of viral RNA expression and viral polymerase activity indicated that WV970 inhibited vRNP-mediated viral genome replication and transcription. Finally, structure-based virtual screening and comprehensive human kinome screening were used to demonstrate that WV970 acts as a multiple kinase inhibitor, many of which are associated with influenza virus replication. Collectively, these results strongly suggest that WV970 is a promising anti-influenza drug candidate and that several kinases associated with viral replication are promising drug targets.

  11. Design of Potent and Orally Active GPR119 Agonists for the Treatment of Type II Diabetes

    PubMed Central

    2015-01-01

    We report herein the design and synthesis of a series of potent and selective GPR119 agonists. Our objective was to develop a GPR119 agonist with properties that were suitable for fixed-dose combination with a DPP4 inhibitor. Starting from a phenoxy analogue (1), medicinal chemistry efforts directed toward reducing half-life and increasing solubility led to the synthesis of a series of benzyloxy analogues. Compound 28 was chosen for further profiling because of its favorable physicochemical properties and excellent GPR119 potency across species. This compound exhibited a clean off-target profile in counterscreens and good in vivo efficacy in mouse oGTT. PMID:26288697

  12. SOMCL-085, a novel multi-targeted FGFR inhibitor, displays potent anticancer activity in FGFR-addicted human cancer models.

    PubMed

    Jiang, Xi-Fei; Dai, Yang; Peng, Xia; Shen, Yan-Yan; Su, Yi; Wei, Man-Man; Liu, Wei-Ren; Ding, Zhen-Bin; Zhang, Ao; Shi, Ying-Hong; Ai, Jing

    2017-09-14

    Aberrant fibroblast growth factor receptor (FGFR) activation is found across a diverse spectrum of malignancies, especially those lacking effective treatments. SOMCL-085 is a novel FGFR-dominant multi-target kinase inhibitor. Here, we explored the FGFR-targeting anticancer activity of SOMCL-085 both in vitro and in vivo. Among a panel of 20 tyrosine kinases screened, SOMCL-085 potently inhibited FGFR1, FGFR2 and FGFR3 kinase activity, with IC50 values of 1.8, 1.9 and 6.9 nmol/L, respectively. This compound simultaneously inhibited the angiogenesis kinases VEGFR and PDGFR, but without obvious inhibitory effect on other 12 tyrosine kinases. In 3 representative human cancer cell lines with different mechanisms of FGFR activation tested, SOMCL-085 (20-500 nmol/L) dose-dependently inhibited FGFR1-3 phosphorylation and the phosphorylation of their key downstream effectors PLCγ and Erk. In 7 FGFR aberrant human cancer cell lines, regardless of the mechanistic complexity of FGFR over-activation, SOMCL-085 potently inhibited FGFR-driven cell proliferation by arresting cells at the G1/S phase. In the FGFR1-amplified lung cancer cell line H1581 xenograft mice and FGFR2-amplified gastric cancer cell line SNU16 xenograft mice, oral administration of SOMCL-085 (25, 50 mg·kg(-1)·d(-1)) for 21 days substantially suppressed tumor growth without affecting their body-weight. These results suggest that SOMCL-085 is a potent multi-target FGFR inhibitor that inhibits the FGFR-dependent neoplastic phenotypes of human cancer cells in vitro and in vivo.

  13. Identification of a Potent Inhibitor of CREB-Mediated Gene Transcription with Efficacious in Vivo Anticancer Activity

    PubMed Central

    2015-01-01

    Recent studies have shown that nuclear transcription factor cyclic adenosine monophosphate response element binding protein (CREB) is overexpressed in many different types of cancers. Therefore, CREB has been pursued as a novel cancer therapeutic target. Naphthol AS-E and its closely related derivatives have been shown to inhibit CREB-mediated gene transcription and cancer cell growth. Previously, we identified naphthamide 3a as a different chemotype to inhibit CREB’s transcription activity. In a continuing effort to discover more potent CREB inhibitors, a series of structural congeners of 3a was designed and synthesized. Biological evaluations of these compounds uncovered compound 3i (666-15) as a potent and selective inhibitor of CREB-mediated gene transcription (IC50 = 0.081 ± 0.04 μM). 666-15 also potently inhibited cancer cell growth without harming normal cells. In an in vivo MDA-MB-468 xenograft model, 666-15 completely suppressed the tumor growth without overt toxicity. These results further support the potential of CREB as a valuable cancer drug target. PMID:26023867

  14. Discovery of potent and selective cytotoxic activity of new quinazoline-ureas against TMZ-resistant glioblastoma multiforme (GBM).

    PubMed

    Elkamhawy, Ahmed; Viswanath, Ambily Nath Indu; Pae, Ae Nim; Kim, Hyeon Young; Heo, Jin-Chul; Park, Woo-Kyu; Lee, Chong-Ock; Yang, Heekyoung; Kim, Kang Ho; Nam, Do-Hyun; Seol, Ho Jun; Cho, Heeyeong; Roh, Eun Joo

    2015-10-20

    Herein, we report new quinazoline-urea based compounds with potent cytotoxic activities against TMZ-resistant glioblastoma multiforme (GBM) cells. Low micromolar IC₅₀ values were exhibited over a panel of three primary GBM patient-derived cell cultures belonging to proneural (GBM-1), mesenchymal (GBM-2), and classical (GBM-3) subtypes. Eight compounds showed excellent selectivity indices for GBM cells comparing to a normal astrocyte cell line. In JC-1 assay, analogues 11, 12, 20, 22, and 24 exerted promising rates of mPTP opening induction towards proneural GBM subtype. Compounds 11, 20, and 24 bound to the translocator protein 18 kDa (TSPO) in submicromolar range using [(3)H] PK-11195 binding affinity assay. A homology model was built and docked models of 11, 12, 20, 22 and 24 were generated for describing their plausible binding modes in TSPO. In 3D clonogenic assay, compound 20 manifested potent tumoricidal effects on TMZ-resistant GBM cells even at submicromolar concentrations. In addition, CYP450 and hERG assays presented a safe toxicity profile of 20. Taken as a whole, this report presents compound 20 as a potent, selective and safe GBM cytotoxic agent which constitutes a promising direction against TMZ-resistant GBM. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. Cathelicidin Antimicrobial Peptides with Reduced Activation of Toll-Like Receptor Signaling Have Potent Bactericidal Activity against Colistin-Resistant Bacteria

    PubMed Central

    Lin, Xiaoyan; Yi, Guanghui; Zhang, Yunliang; Rowe-Magnus, Dean A.; Bush, Karen

    2016-01-01

    ABSTRACT The world is at the precipice of a postantibiotic era in which medical procedures and minor injuries can result in bacterial infections that are no longer effectively treated by antibiotics. Cathelicidins are peptides produced by animals to combat bacterial infections and to regulate innate immune responses. However, cathelicidins are potent activators of the inflammatory response. Cathelicidins with reduced proinflammatory activity and potent bactericidal activity in the low micromolar range against Gram-negative bacteria have been identified. Motifs in cathelicidins that impact bactericidal activity and cytotoxicity to human cells have been elucidated and used to generate peptides that have reduced activation of proinflammatory cytokine production and reduced cytotoxicity to human cells. The resultant peptides have bactericidal activities comparable to that of colistin and can kill colistin-resistant bacteria. PMID:27651360

  16. Potent in vitro and in vivo antitoxoplasma activity of the lipid-soluble antifolate trimetrexate.

    PubMed Central

    Allegra, C J; Kovacs, J A; Drake, J C; Swan, J C; Chabner, B A; Masur, H

    1987-01-01

    Trimetrexate, a highly lipid-soluble quinazoline antifolate now undergoing trials as an anticancer agent, was found to be a potent inhibitor of the dihydrofolate reductase (DHFR) isolated from Toxoplasma gondii. The concentration required for 50% inhibition of protozoal DHFR was 1.4 nM. As an inhibitor of this enzyme, trimetrexate was almost 600-fold (amount of antifolate required to inhibit catalytic reaction by 50%) and 750-fold (inhibition constant) more potent than pyrimethamine, the DHFR inhibitor currently used to treat toxoplasma infection. When the protozoan was incubated with 1 microM trimetrexate, the drug rapidly reached high intracellular concentrations. Since toxoplasma organisms lack a transmembrane transport system for physiologic folates, host toxicity can be prevented by co-administration of the reduced folate, leucovorin, without reversing the antiprotozoal effect. The effectiveness of trimetrexate against toxoplasma was demonstrated both in vitro and vivo. Proliferation of toxoplasma in murine macrophages in vitro was completely inhibited by exposure of these cells to 10(-7) M trimetrexate for 18 h. When used alone, trimetrexate was able to extend the survival of T. gondii-infected mice. PMID:2948969

  17. Rice Bran Protein as a Potent Source of Antimelanogenic Peptides with Tyrosinase Inhibitory Activity.

    PubMed

    Ochiai, Akihito; Tanaka, Seiya; Tanaka, Takaaki; Taniguchi, Masayuki

    2016-10-28

    Rice (Oryza sativa) is consumed as a staple food globally, and rice bran, the byproduct, is an unused biomass that is ultimately discarded as waste. Thus, in the present study, a technique for producing tyrosinase inhibitory peptides from rice bran protein (RBP) was developed. Simultaneous treatment of RBP with chymotrypsin and trypsin produced numerous peptides. Subsequently, six tyrosinase inhibitory peptides were isolated from the hydrolysate fractions in a multistep purification protocol, and their amino acid sequences were determined. Three of these peptides had a C-terminal tyrosine residue and exhibited significant inhibitory effects against tyrosinase-mediated monophenolase reactions. Furthermore, peptide CT-2 (Leu-Gln-Pro-Ser-His-Tyr) potently inhibited melanogenesis in mouse B16 melanoma cells without causing cytotoxicity, suggesting the potential of CT-2 as an agent for melanin-related skin disorder treatment. The present data indicate that RBP is a potent source of tyrosinase inhibitory peptides and that simultaneous treatment of RBP with chymotrypsin and trypsin efficiently produces these peptides.

  18. Potent Adjuvant Activity of Cationic Liposome-DNA Complexes for Genital Herpes Vaccines▿

    PubMed Central

    Bernstein, David I.; Cardin, Rhonda D.; Bravo, Fernando J.; Strasser, Jane E.; Farley, Nicholas; Chalk, Claudia; Lay, Marla; Fairman, Jeff

    2009-01-01

    Development of a herpes simplex virus (HSV) vaccine is a priority because these infections are common. It appears that potent adjuvants will be required to augment the immune response to subunit HSV vaccines. Therefore, we evaluated cationic liposome-DNA complexes (CLDC) as an adjuvant in a mouse model of genital herpes. Using a whole-virus vaccine (HVAC), we showed that the addition of CLDC improved antibody responses compared to vaccine alone. Most important, CLDC increased survival, reduced symptoms, and decreased vaginal virus replication compared to vaccine alone or vaccine administered with monophosphoryl lipid A (MPL) plus trehalose dicorynomycolate (TDM) following intravaginal challenge of mice. When CLDC was added to an HSV gD2 vaccine, it increased the amount of gamma interferon that was produced from splenocytes stimulated with gD2 compared to the amount produced with gD2 alone or with MPL-alum. The addition of CLDC to the gD2 vaccine also improved the outcome following vaginal HSV type 2 challenge compared to vaccine alone and was equivalent to vaccination with an MPL-alum adjuvant. CLDC appears to be a potent adjuvant for HSV vaccines and should be evaluated further. PMID:19279167

  19. A novel lectin with highly potent antiproliferative and HIV-1 reverse transcriptase inhibitory activities from cicada (Cicada flammata).

    PubMed

    Ye, Xiu Juan; Ng, Tzi Bun

    2010-05-01

    A dimeric lectin with a molecular weight of 60 kDa and high hemagglutinating activity was isolated from dried cicadas. It was adsorbed on Q-Sepharose and unadsorbed on Affi-Gel Blue gel. Its hemagglutinating activity was stable up to 55 degrees C and between pH 2 and 13. The activity was inhibited by glucuronic acid and raffinose, K(+) ions, and Mg(2+) ions. Cicada lectin potently inhibited proliferation of HepG2 hepatoma and MCF 7 breast cancer cells, with an IC(50) value of 0.76 and 0.49 microM, respectively. It potently inhibited HIV-1 reverse transcriptase activity with an IC(50) of 0.36 microM but was devoid of mitogenic activity on spleen cells. Its N-terminal sequence exhibited slight similarity to a conserved hypothetical protein from Culex quinquefasciatus and a gene product from transcript GH19834-RA of Drosophila grimshawi, but there was no resemblance to lectins from other insects, including Drosophila, Sarcophaga, Glossina, and Aedes species.

  20. Resveratrol potently reduces prostaglandin E2 production and free radical formation in lipopolysaccharide-activated primary rat microglia

    PubMed Central

    Candelario-Jalil, Eduardo; de Oliveira, Antonio C Pinheiro; Gräf, Sybille; Bhatia, Harsharan S; Hüll, Michael; Muñoz, Eduardo; Fiebich, Bernd L

    2007-01-01

    Background Neuroinflammatory responses are triggered by diverse ethiologies and can provide either beneficial or harmful results. Microglial cells are the major cell type involved in neuroinflammation, releasing several mediators, which contribute to the neuronal demise in several diseases including cerebral ischemia and neurodegenerative disorders. Attenuation of microglial activation has been shown to confer protection against different types of brain injury. Recent evidence suggests that resveratrol has anti-inflammatory and potent antioxidant properties. It has been also shown that resveratrol is a potent inhibitor of cyclooxygenase (COX)-1 activity. Previous findings have demonstrated that this compound is able to reduce neuronal injury in different models, both in vitro and in vivo. The aim of this study was to examine whether resveratrol is able to reduce prostaglandin E2 (PGE2) and 8-iso-prostaglandin F2α (8-iso-PGF2α) production by lipopolysaccharide (LPS)-activated primary rat microglia. Methods Primary microglial cell cultures were prepared from cerebral cortices of neonatal rats. Microglial cells were stimulated with 10 ng/ml of LPS in the presence or absence of different concentrations of resveratrol (1–50 μM). After 24 h incubation, culture media were collected to measure the production of PGE2 and 8-iso-PGF2α using enzyme immunoassays. Protein levels of COX-1, COX-2 and microsomal prostaglandin E synthase-1 (mPGES-1) were studied by Western blotting after 24 h of incubation with LPS. Expression of mPGES-1 at the mRNA level was investigated using reverse transcription-polymerase chain reaction (RT-PCR) analysis. Results Our results indicate that resveratrol potently reduced LPS-induced PGE2 synthesis and the formation of 8-iso-PGF2α, a measure of free radical production. Interestingly, resveratrol dose-dependently reduced the expression (mRNA and protein) of mPGES-1, which is a key enzyme responsible for the synthesis of PGE2 by activated

  1. Structural analysis of proanthocyanidins isolated from fruit stone of Chinese hawthorn with potent antityrosinase and antioxidant activity.

    PubMed

    Chai, Wei-Ming; Chen, Chih-Min; Gao, Yu-Sen; Feng, Hui-Ling; Ding, Yu-Mei; Shi, Yan; Zhou, Han-Tao; Chen, Qing-Xi

    2014-01-08

    Proanthocyanidins were isolated from fruit stone of Chinese hawthorn (Crataegus pinnatifida Bge. var. major N.E.Br.). Their structures were analyzed and elucidated by methods of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS). The results demonstrated that these compounds are complicated mixtures of homo- and heteropolymers consisting of procyanidin/procyanidin gallate and prodelphinidin. They possessed structural heterogeneity in monomer units, polymer length, and interflavan linkage (A-type and B-type). Their antityrosinase and antioxidant activity were then investigated. The results revealed that they can inhibit tyrosinase activities, including the monophenolase activity and the diphenolase activity. In addition, proanthocyanidins possessed potent antioxidant activity. Our studies revealed that proanthocyanidins isolated from fruit stone of Chinese hawthorn may be applied in food, agriculture, pharmaceutical, and cosmetic industries.

  2. Isopentenyl pyrophosphate-activated CD56+ {gamma}{delta} T lymphocytes display potent antitumor activity toward human squamous cell carcinoma.

    PubMed

    Alexander, Alan A Z; Maniar, Amudhan; Cummings, Jean-Saville; Hebbeler, Andrew M; Schulze, Dan H; Gastman, Brian R; Pauza, C David; Strome, Scott E; Chapoval, Andrei I

    2008-07-01

    The expression of CD56, a natural killer cell-associated molecule, on alphabeta T lymphocytes correlates with their increased antitumor effector function. CD56 is also expressed on a subset of gammadelta T cells. However, antitumor effector functions of CD56(+) gammadelta T cells are poorly characterized. To investigate the potential effector role of CD56(+) gammadelta T cells in tumor killing, we used isopentenyl pyrophosphate and interleukin-2-expanded gammadelta T cells from peripheral blood mononuclear cells of healthy donors. Thirty to 70% of expanded gammadelta T cells express CD56 on their surface. Interestingly, although both CD56(+) and CD56(-) gammadelta T cells express comparable levels of receptors involved in the regulation of gammadelta T-cell cytotoxicity (e.g., NKG2D and CD94), only CD56(+) gammadelta T lymphocytes are capable of killing squamous cell carcinoma and other solid tumor cell lines. This effect is likely mediated by the enhanced release of cytolytic granules because CD56(+) gammadelta T lymphocytes expressed higher levels of CD107a compared with CD56(-) controls following exposure to tumor cell lines. Lysis of tumor cell lines is blocked by concanamycin A and a combination of anti-gammadelta T-cell receptor + anti-NKG2D monoclonal antibody, suggesting that the lytic activity of CD56(+) gammadelta T cells involves the perforin-granzyme pathway and is mainly gammadelta T-cell receptor/NKG2D dependent. Importantly, CD56-expressing gammadelta T lymphocytes are resistant to Fas ligand and chemically induced apoptosis. Our data indicate that CD56(+) gammadelta T cells are potent antitumor effectors capable of killing squamous cell carcinoma and may play an important therapeutic role in patients with head and neck cancer and other malignancies.

  3. A Lipopeptide HIV-1/2 Fusion Inhibitor with Highly Potent In Vitro, Ex Vivo, and In Vivo Antiviral Activity.

    PubMed

    Chong, Huihui; Xue, Jing; Xiong, Shengwen; Cong, Zhe; Ding, Xiaohui; Zhu, Yuanmei; Liu, Zixuan; Chen, Ting; Feng, Yifan; He, Lei; Guo, Yan; Wei, Qiang; Zhou, Yusen; Qin, Chuan; He, Yuxian

    2017-06-01

    Peptides derived from the C-terminal heptad repeat (CHR) region of the human immunodeficiency virus type 1 (HIV-1) fusogenic protein gp41 are potent viral entry inhibitors, and currently, enfuvirtide (T-20) is the only one approved for clinical use; however, emerging drug resistance largely limits its efficacy. In this study, we generated a novel lipopeptide inhibitor, named LP-19, by integrating multiple design strategies, including an N-terminal M-T hook structure, an HIV-2 sequence, intrahelical salt bridges, and a membrane-anchoring lipid tail. LP-19 showed stable binding affinity and highly potent, broad, and long-lasting antiviral activity. In in vitro studies, LP-19 efficiently inhibited HIV-1-, HIV-2-, and simian immunodeficiency virus (SIV)-mediated cell fusion, viral entry, and infection, and it was highly active against diverse subtypes of primary HIV-1 isolates and inhibitor-resistant mutants. Ex vivo studies demonstrated that LP-19 exhibited dramatically increased anti-HIV activity and an extended half-life in rhesus macaques. In short-term monotherapy, LP-19 reduced viral loads to undetectable levels in acutely and chronically simian-human immunodeficiency virus (SHIV)-infected monkeys. Therefore, this study offers an ideal HIV-1/2 fusion inhibitor for clinical development and emphasizes the importance of the viral fusion step as a drug target.IMPORTANCE The peptide drug T-20 is the only viral fusion inhibitor in the clinic, which is used for combination therapy of HIV-1 infection; however, it requires a high dosage and easily induces drug resistance, calling for a new drug with significantly improved pharmaceutical profiles. Here, we have developed a short-lipopeptide-based fusion inhibitor, termed LP-19, which mainly targets the conserved gp41 pocket site and shows highly potent inhibitory activity against HIV-1, HIV-2, and even SIV isolates. LP-19 exhibits dramatically increased antiviral activity and an extended half-life in rhesus macaques, and

  4. 6-Hydroxyflavone and Derivatives Exhibit Potent Anti-Inflammatory Activity among Mono-, Di- and Polyhydroxylated Flavones in Kidney Mesangial Cells

    PubMed Central

    Sidhu, Preetpal Singh; Desai, Umesh R.; Zhou, Qibing

    2015-01-01

    Inflammatory responses by kidney mesangial cells play a critical role in the glomerulonephritis. The anti-inflammatory potential of nineteen mono-, di- and polyhydroxylated flavones including fisetin, quercetin, morin, tricetin, gossypetin, apigenin and myricetin were investigated on rat mesangial cells with lipopolysaccharide (LPS) as the inflammatory stimuli. 6-Hydroxyflavone and 4′,6-dihydroxyflavone exhibited high activity with IC50 in the range of 2.0 μM, a much better inhibition potential in comparison to the well-studied polyhydroxylated flavones. Interestingly, the anti-inflammatory activity was not due to direct quenching of NO radicals. Investigation on derivatives with methylation, acetylation or sulfation of 6-hydroxyl group revealed that 6-methoxyflavone was the most potent with an IC50 of 192 nM. Mechanistic study indicated that the anti-inflammatory activity of 6-methoxyflavone arose via the inhibition of LPS-induced downstream inducible NO synthase in mesangial cells. The identification of 6-hydroxyflavone and 6-methoxyflavone with potent anti-inflammatory activity in kidney mesangial cells provides a new flavone scaffold and direction to develop naturally derived products for potential nephritis prevention and treatment. PMID:25790236

  5. BO-1055, a novel DNA cross-linking agent with remarkable low myelotoxicity shows potent activity in sarcoma models

    PubMed Central

    Ambati, Srikanth R.; Shieh, Jae-Hung; Pera, Benet; Lopes, Eloisi Caldas; Chaudhry, Anisha; Wong, Elissa W.P.; Saxena, Ashish; Su, Tsann-Long; Moore, Malcolm A.S.

    2016-01-01

    DNA damaging agents cause rapid shrinkage of tumors and form the basis of chemotherapy for sarcomas despite significant toxicities. Drugs having superior efficacy and wider therapeutic windows are needed to improve patient outcomes. We used cell proliferation and apoptosis assays in sarcoma cell lines and benign cells; γ-H2AX expression, comet assay, immunoblot analyses and drug combination studies in vitro and in patient derived xenograft (PDX) models. BO-1055 caused apoptosis and cell death in a concentration and time dependent manner in sarcoma cell lines. BO-1055 had potent activity (submicromolar IC50) against Ewing sarcoma and rhabdomyosarcoma, intermediate activity in DSRCT (IC50 = 2-3μM) and very weak activity in osteosarcoma (IC50 >10μM) cell lines. BO-1055 exhibited a wide therapeutic window compared to other DNA damaging drugs. BO-1055 induced more DNA double strand breaks and γH2AX expression in cancer cells compared to benign cells. BO-1055 showed inhibition of tumor growth in A673 xenografts and caused tumor regression in cyclophosphamide resistant patient-derived Ewing sarcoma xenografts and A204 xenografts. Combination of BO-1055 and irinotecan demonstrated synergism in Ewing sarcoma PDX models. Potent activity on sarcoma cells and its relative lack of toxicity presents a strong rationale for further development of BO-1055 as a therapeutic agent. PMID:27248664

  6. Potent Vinblastine C20′ Ureas Displaying Additionally Improved Activity Against a Vinblastine-Resistant Cancer Cell Line

    PubMed Central

    2013-01-01

    A series of disubstituted C20′-urea derivatives of vinblastine were prepared from 20′-aminovinblastine that was made accessible through a unique Fe(III)/NaBH4-mediated alkene functionalization reaction of anhydrovinblastine. Three analogues were examined across a panel of 15 human tumor cell lines, displaying remarkably potent cell growth inhibition activity (avg. IC50 = 200–300 pM), being 10–200-fold more potent than vinblastine (avg. IC50 = 6.1 nM). Significantly, the analogues also display further improved activity against the vinblastine-resistant HCT116/VM46 cell line that bears the clinically relevant overexpression of Pgp, exhibiting IC50 values on par with that of vinblastine against the sensitive HCT116 cell line, 100–200-fold greater than the activity of vinblastine against the resistant HCT116/VM46 cell line, and display a reduced 10–20-fold activity differential between the matched sensitive and resistant cell lines (vs 100-fold for vinblastine). PMID:24223237

  7. 6-Hydroxyflavone and derivatives exhibit potent anti-inflammatory activity among mono-, di- and polyhydroxylated flavones in kidney mesangial cells.

    PubMed

    Wang, Xing; Wang, Zhiwei; Sidhu, Preetpal Singh; Desai, Umesh R; Zhou, Qibing

    2015-01-01

    Inflammatory responses by kidney mesangial cells play a critical role in the glomerulonephritis. The anti-inflammatory potential of nineteen mono-, di- and polyhydroxylated flavones including fisetin, quercetin, morin, tricetin, gossypetin, apigenin and myricetin were investigated on rat mesangial cells with lipopolysaccharide (LPS) as the inflammatory stimuli. 6-Hydroxyflavone and 4',6-dihydroxyflavone exhibited high activity with IC50 in the range of 2.0 μM, a much better inhibition potential in comparison to the well-studied polyhydroxylated flavones. Interestingly, the anti-inflammatory activity was not due to direct quenching of NO radicals. Investigation on derivatives with methylation, acetylation or sulfation of 6-hydroxyl group revealed that 6-methoxyflavone was the most potent with an IC50 of 192 nM. Mechanistic study indicated that the anti-inflammatory activity of 6-methoxyflavone arose via the inhibition of LPS-induced downstream inducible NO synthase in mesangial cells. The identification of 6-hydroxyflavone and 6-methoxyflavone with potent anti-inflammatory activity in kidney mesangial cells provides a new flavone scaffold and direction to develop naturally derived products for potential nephritis prevention and treatment.

  8. Potent drugs that attenuate anti-Candida albicans activity of fluconazole and their possible mechanisms of action.

    PubMed

    Urai, Makoto; Kaneko, Yukihiro; Niki, Mamiko; Inoue, Manabu; Tanabe, Koichi; Umeyama, Takashi; Fukazawa, Hidesuke; Ohno, Hideaki; Miyazaki, Yoshitsugu

    2014-10-01

    Fluconazole (FLCZ) is a first-line drug for treating Candida albicans infections, but clinical failure due to reduced sensitivity is a growing concern. Our previous study suggested that certain drug combinations pose a particular challenge in potently reducing FLCZ's anti-C. albicans activity, and cyclooxygenase inhibitors formed the major group of these attenuating drugs in combination with FLCZ. In this study, we examined the effects of diclofenac sodium (DFNa) and related compounds in combination with FLCZ against C. albicans, and investigated their possible mechanisms of interaction. DFNa, ibuprofen, and omeprazole elevated the minimum inhibitory concentration (MIC) of FLCZ by 8-, 4-, and 4-fold, respectively; however, loxoprofen sodium and celecoxib did not. An analogue of DFNa, 2,6-dichlorodiphenylamine, also elevated the MIC by 4-fold. Gene expression analysis revealed that diclofenac sodium induced CDR1 efflux pump activity, but not CDR2 activity. In addition, an efflux pump CDR1 mutant, which was manipulated to not be induced by DFNa, showed less elevation of MIC compared to that shown by the wild type. Therefore, DFNa and related compounds are potent factors for reducing the sensitivity of C. albicans to FLCZ partly via induction of an efflux pump. Although it is not known whether such antagonism is relevant to the clinical treatment failure observed, further investigation of the molecular mechanisms underlying the reduction of FLCZ's anti-C. albicans activity is expected to promote safer and more effective use of the drug.

  9. Structure-activity relationship study of Vitamin K derivatives yields highly potent neuroprotective agents

    PubMed Central

    Josey, Benjamin J.; Inks, Elizabeth S.; Wen, Xuejun; Chou, C. James

    2013-01-01

    Historically known for its role in blood coagulation and bone formation, Vitamin K (VK) has begun to emerge as an important nutrient for brain function. While VK involvement in the brain has not been fully explored, it is well known that oxidative stress plays a critical role in neurodegenerative diseases. It was recently reported that VK protects neurons and oligodendrocytes from oxidative injury and rescues Drosophila from mitochondrial defects associated with Parkinson’s Disease. In this study, we take a chemical approach to define the optimal and minimum pharmacophore responsible for the neuroprotective effects of VK. In doing so, we have developed a series of potent VK analogs with favorable drug characteristics that provide full protection at nanomolar concentrations in a well-defined model of neuronal oxidative stress. Additionally, we have characterized key cellular responses and biomarkers consistent with the compounds’ ability to rescue cells from oxidative stress induced cell death. PMID:23327468

  10. A Potent Gelatinase Inhibitor with Anti-Tumor-Invasive Activity and its Metabolic Disposition

    PubMed Central

    Lee, Mijoon; Celenza, Giuseppe; Boggess, Bill; Blase, Jennifer; Shi, Qicun; Toth, Marta; Bernardo, M. Margarida; Wolter, William R.; Suckow, Mark A.; Hesek, Dusan; Noll, Bruce C.; Fridman, Rafael; Mobashery, Shahriar; Chang, Mayland

    2009-01-01

    Metastatic tumors lead to more than 90% fatality. Despite the importance of invasiveness of tumors to poor disease outcome, no anti-invasive compounds have been commercialized. We describe herein the synthesis and evaluation of 4-(4-(thiiranylmethylsulfonyl)phenoxy)-phenyl methane-sulfonate (compound 2) as a potent and selective inhibitor of gelatinases (matrix metalloproteinases-2 and -9), two enzymes implicated in invasiveness of tumors. It was demonstrated that compound 2 significantly attenuated the invasiveness of human fibrosarcoma cells (HT1080). The metabolism of compound 2 involved hydroxylation at the a-methylene, which generates sulfinic acid, thiirane ring-opening, followed by methylation and oxidation, and cysteine conjugation of both the thiirane and phenyl rings. PMID:19207421

  11. Structure-activity relationship study of vitamin k derivatives yields highly potent neuroprotective agents.

    PubMed

    Josey, Benjamin J; Inks, Elizabeth S; Wen, Xuejun; Chou, C James

    2013-02-14

    Historically known for its role in blood coagulation and bone formation, vitamin K (VK) has begun to emerge as an important nutrient for brain function. While VK involvement in the brain has not been fully explored, it is well-known that oxidative stress plays a critical role in neurodegenerative diseases. It was recently reported that VK protects neurons and oligodendrocytes from oxidative injury and rescues Drosophila from mitochondrial defects associated with Parkinson's disease. In this study, we take a chemical approach to define the optimal and minimum pharmacophore responsible for the neuroprotective effects of VK. In doing so, we have developed a series of potent VK analogues with favorable drug characteristics that provide full protection at nanomolar concentrations in a well-defined model of neuronal oxidative stress. Additionally, we have characterized key cellular responses and biomarkers consistent with the compounds' ability to rescue cells from oxidative stress induced cell death.

  12. Discovery and Characterization of a Potent Interleukin-6 Binding Peptide with Neutralizing Activity In Vivo

    PubMed Central

    Ranganath, Sheila; Bhandari, Ashok; Avitahl-Curtis, Nicole; McMahon, Jaimee; Wachtel, Derek; Zhang, Jenny; Leitheiser, Christopher; Bernier, Sylvie G.; Liu, Guang; Tran, Tran T.; Celino, Herodion; Tobin, Jenny; Jung, Joon; Zhao, Hong; Glen, Katie E.; Graul, Chris; Griffin, Aliesha; Schairer, Wayne C.; Higgins, Carolyn; Reza, Tammi L.; Mowe, Eva; Rivers, Sam; Scott, Sonya; Monreal, Alex; Shea, Courtney; Bourne, Greg; Coons, Casey; Smith, Adaline; Tang, Kim; Mandyam, Ramya A.; Masferrer, Jaime; Liu, David; Patel, Dinesh V.; Fretzen, Angelika; Murphy, Craig A.; Milne, G. Todd; Smythe, Mark L.; Carlson, Kenneth E.

    2015-01-01

    Interleukin-6 (IL-6) is an important member of the cytokine superfamily, exerting pleiotropic actions on many physiological processes. Over-production of IL-6 is a hallmark of immune-mediated inflammatory diseases such as Castleman’s Disease (CD) and rheumatoid arthritis (RA). Antagonism of the interleukin IL-6/IL-6 receptor (IL-6R)/gp130 signaling complex continues to show promise as a therapeutic target. Monoclonal antibodies (mAbs) directed against components of this complex have been approved as therapeutics for both CD and RA. To potentially provide an additional modality to antagonize IL-6 induced pathophysiology, a peptide-based antagonist approach was undertaken. Using a combination of molecular design, phage-display, and medicinal chemistry, disulfide-rich peptides (DRPs) directed against IL-6 were developed with low nanomolar potency in inhibiting IL-6-induced pSTAT3 in U937 monocytic cells. Targeted PEGylation of IL-6 binding peptides resulted in molecules that retained their potency against IL-6 and had a prolongation of their pharmacokinetic (PK) profiles in rodents and monkeys. One such peptide, PN-2921, contained a 40 kDa polyethylene glycol (PEG) moiety and inhibited IL-6-induced pSTAT3 in U937 cells with sub-nM potency and possessed 23, 36, and 59 h PK half-life values in mice, rats, and cynomolgus monkeys, respectively. Parenteral administration of PN-2921 to mice and cynomolgus monkeys potently inhibited IL-6-induced biomarker responses, with significant reductions in the acute inflammatory phase proteins, serum amyloid A (SAA) and C-reactive protein (CRP). This potent, PEGylated IL-6 binding peptide offers a new approach to antagonize IL-6-induced signaling and associated pathophysiology. PMID:26555695

  13. Structure−Activity Study of Dihydrocinnamic Acids and Discovery of the Potent FFA1 (GPR40) Agonist TUG-469

    PubMed Central

    2010-01-01

    The free fatty acid 1 receptor (FFA1 or GPR40), which is highly expressed on pancreatic β-cells and amplifies glucose-stimulated insulin secretion, has emerged as an attractive target for the treatment of type 2 diabetes. Several FFA1 agonists containing the para-substituted dihydrocinnamic acid moiety are known. We here present a structure−activity relationship study of this compound family suggesting that the central methyleneoxy linker is preferable for the smaller compounds, whereas the central methyleneamine linker gives higher potency to the larger compounds. The study resulted in the discovery of the potent and selective full FFA1 agonist TUG-469 (29). PMID:24900217

  14. Discovery of potent CCR4 antagonists: Synthesis and structure-activity relationship study of 2,4-diaminoquinazolines.

    PubMed

    Yokoyama, Kazuhiro; Ishikawa, Noriko; Igarashi, Susumu; Kawano, Noriyuki; Hattori, Kazuyuki; Miyazaki, Takahiro; Ogino, Shin-ichi; Matsumoto, Yuzo; Takeuchi, Makoto; Ohta, Mitsuaki

    2008-07-15

    A new series of quinazolines that function as CCR4 antagonists were discovered during the screening of our corporate compound libraries. Subsequent compound optimization elucidated the structure-activity relationships and led the identification of 2-(1,4'-bipiperidine-1'-yl)-N-cycloheptyl-6,7-dimethoxyquinazolin-4-amine 14a, which showed potent inhibition in the [(35)S]GTPgammaS-binding assay (IC(50)=18nM). This compound also inhibited the chemotaxis of human and mouse CCR4-expressing cells (IC(50)=140nM, 39nM).

  15. Synthesis and in vitro activity of dicationic indolyl diphenyl ethers as novel potent antibiotic agents against drug-resistant bacteria.

    PubMed

    Chen, Xiaofang; Hu, Xinxin; Wu, Yanbin; Liu, Yonghua; Bian, Cong; Nie, Tongying; You, Xuefu; Hu, Laixing

    2017-02-15

    A series of 4,4'-bis-[2-(6-N-substituted-amidino)indolyl] diphenyl ether have been synthesized and tested for their in vitro antibacterial activity including a range of Gram-positive and Gram-negative pathogens and cytotoxicity. Most of these compounds have mainly shown anti-Gram positive bacteria activities especially against drug resistant bacterial strains MRSA, MRSE and VRE. The anti-MRSA and anti-MRSE activities of compound 7a and 7j were more potent than that of the lead compound 2, levofloxacin and vancomycin. Interestingly, 7j had greatly improved anti negative bacterial activity, especially for the producing NDM-1 Klebsiella pneumonia strain and less toxic than that of the lead compound 2. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Discovery of the First N-Hydroxycinnamamide-Based Histone Deacetylase 1/3 Dual Inhibitors with Potent Oral Antitumor Activity

    PubMed Central

    2015-01-01

    In our previous study, we designed and synthesized a novel series of N-hydroxycinnamamide-based HDAC inhibitors (HDACIs), among which the representative compound 14a exhibited promising HDACs inhibition and antitumor activity. In this current study, we report the development of a more potent class of N-hydroxycinnamamide-based HDACIs, using 14a as lead, among which, compound 11r gave IC50 values of 11.8, 498.1, 3.9, 2000.8, 5700.4, 308.2, and 900.4 nM for the inhibition of HDAC1, HDAC2, HDAC3, HDAC8, HDAC4, HDAC6, and HDAC11, exhibiting dual HDAC1/3 selectivity. Compounds 11e, 11r, 11w, and 11y showed excellent growth inhibition in multiple tumor cell lines. In vivo antitumor assay in U937 xenograft model identified compound 11r as a potent, orally active HDACI. To the best of our knowledge, this work constitutes the first report of oral active N-hydroxycinnamamide-based HDACIs with dual HDAC1/3 selectivity. PMID:24694055

  17. CD33-specific chimeric antigen receptor T cells exhibit potent preclinical activity against human acute myeloid leukemia

    PubMed Central

    Kenderian, SS; Ruella, M; Shestova, O; Klichinsky, M; Aikawa, V; Morrissette, JJD; Scholler, J; Song, D; Porter, DL; Carroll, M; June, CH; Gill, S

    2015-01-01

    Patients with chemo-refractory acute myeloid leukemia (AML) have a dismal prognosis. Chimeric antigen receptor T (CART) cell therapy has produced exciting results in CD19+ malignancies and may overcome many of the limitations of conventional leukemia therapies. We developed CART cells to target CD33 (CART33) using the anti-CD33 single chain variable fragment used in gemtuzumab ozogamicin (clone My96) and tested the activity and toxicity of these cells. CART33 exhibited significant effector functions in vitro and resulted in eradication of leukemia and prolonged survival in AML xenografts. CART33 also resulted in human lineage cytopenias and reduction of myeloid progenitors in xenograft models of hematopoietic toxicity, suggesting that permanently expressed CD33-specific CART cells would have unacceptable toxicity. To enhance the viability of CART33 as an option for AML, we designed a transiently expressed mRNA anti-CD33 CAR. Gene transfer was carried out by electroporation into T cells and resulted in high-level expression with potent but self-limited activity against AML. Thus our preclinical studies show potent activity of CART33 and indicate that transient expression of anti-CD33 CAR by RNA modification could be used in patients to avoid long-term myelosuppression. CART33 therapy could be used alone or as part of a preparative regimen prior to allogeneic transplantation in refractory AML. PMID:25721896

  18. CD33-specific chimeric antigen receptor T cells exhibit potent preclinical activity against human acute myeloid leukemia.

    PubMed

    Kenderian, S S; Ruella, M; Shestova, O; Klichinsky, M; Aikawa, V; Morrissette, J J D; Scholler, J; Song, D; Porter, D L; Carroll, M; June, C H; Gill, S

    2015-08-01

    Patients with chemo-refractory acute myeloid leukemia (AML) have a dismal prognosis. Chimeric antigen receptor T (CART) cell therapy has produced exciting results in CD19+ malignancies and may overcome many of the limitations of conventional leukemia therapies. We developed CART cells to target CD33 (CART33) using the anti-CD33 single chain variable fragment used in gemtuzumab ozogamicin (clone My96) and tested the activity and toxicity of these cells. CART33 exhibited significant effector functions in vitro and resulted in eradication of leukemia and prolonged survival in AML xenografts. CART33 also resulted in human lineage cytopenias and reduction of myeloid progenitors in xenograft models of hematopoietic toxicity, suggesting that permanently expressed CD33-specific CART cells would have unacceptable toxicity. To enhance the viability of CART33 as an option for AML, we designed a transiently expressed mRNA anti-CD33 CAR. Gene transfer was carried out by electroporation into T cells and resulted in high-level expression with potent but self-limited activity against AML. Thus our preclinical studies show potent activity of CART33 and indicate that transient expression of anti-CD33 CAR by RNA modification could be used in patients to avoid long-term myelosuppression. CART33 therapy could be used alone or as part of a preparative regimen prior to allogeneic transplantation in refractory AML.

  19. Phenylthiazole Antibacterial Agents Targeting Cell Wall Synthesis Exhibit Potent Activity in Vitro and in Vivo against Vancomycin-Resistant Enterococci.

    PubMed

    Mohammad, Haroon; Younis, Waleed; Chen, Lu; Peters, Christine E; Pogliano, Joe; Pogliano, Kit; Cooper, Bruce; Zhang, Jianan; Mayhoub, Abdelrahman; Oldfield, Eric; Cushman, Mark; Seleem, Mohamed N

    2017-03-23

    The emergence of antibiotic-resistant bacterial species, such as vancomycin-resistant enterococci (VRE), necessitates the development of new antimicrobials. Here, we investigate the spectrum of antibacterial activity of three phenylthiazole-substituted aminoguanidines. These compounds possess potent activity against VRE, inhibiting growth of clinical isolates at concentrations as low as 0.5 μg/mL. The compounds exerted a rapid bactericidal effect, targeting cell wall synthesis. Transposon mutagenesis suggested three possible targets: YubA, YubB (undecaprenyl diphosphate phosphatase (UPPP)), and YubD. Both UPPP as well as undecaprenyl diphosphate synthase were inhibited by compound 1. YubA and YubD are annotated as transporters and may also be targets because 1 collapsed the proton motive force in membrane vesicles. Using Caenorhabditis elegans, we demonstrate that two compounds (1, 3, at 20 μg/mL) retain potent activity in vivo, significantly reducing the burden of VRE in infected worms. Taken altogether, the results indicate that compounds 1 and 3 warrant further investigation as novel antibacterial agents against drug-resistant enterococci.

  20. Discovery of the first N-hydroxycinnamamide-based histone deacetylase 1/3 dual inhibitors with potent oral antitumor activity.

    PubMed

    Li, Xiaoyang; Inks, Elizabeth S; Li, Xiaoguang; Hou, Jinning; Chou, C James; Zhang, Jian; Jiang, Yuqi; Zhang, Yingjie; Xu, Wenfang

    2014-04-24

    In our previous study, we designed and synthesized a novel series of N-hydroxycinnamamide-based HDAC inhibitors (HDACIs), among which the representative compound 14a exhibited promising HDACs inhibition and antitumor activity. In this current study, we report the development of a more potent class of N-hydroxycinnamamide-based HDACIs, using 14a as lead, among which, compound 11r gave IC50 values of 11.8, 498.1, 3.9, 2000.8, 5700.4, 308.2, and 900.4 nM for the inhibition of HDAC1, HDAC2, HDAC3, HDAC8, HDAC4, HDAC6, and HDAC11, exhibiting dual HDAC1/3 selectivity. Compounds 11e, 11r, 11w, and 11y showed excellent growth inhibition in multiple tumor cell lines. In vivo antitumor assay in U937 xenograft model identified compound 11r as a potent, orally active HDACI. To the best of our knowledge, this work constitutes the first report of oral active N-hydroxycinnamamide-based HDACIs with dual HDAC1/3 selectivity.

  1. Ivermectin is a potent inhibitor of flavivirus replication specifically targeting NS3 helicase activity: new prospects for an old drug

    PubMed Central

    Mastrangelo, Eloise; Pezzullo, Margherita; De Burghgraeve, Tine; Kaptein, Suzanne; Pastorino, Boris; Dallmeier, Kai; de Lamballerie, Xavier; Neyts, Johan; Hanson, Alicia M.; Frick, David N.; Bolognesi, Martino; Milani, Mario

    2012-01-01

    Objectives Infection with yellow fever virus (YFV), the prototypic mosquito-borne flavivirus, causes severe febrile disease with haemorrhage, multi-organ failure and a high mortality. Moreover, in recent years the Flavivirus genus has gained further attention due to re-emergence and increasing incidence of West Nile, dengue and Japanese encephalitis viruses. Potent and safe antivirals are urgently needed. Methods Starting from the crystal structure of the NS3 helicase from Kunjin virus (an Australian variant of West Nile virus), we identified a novel, unexploited protein site that might be involved in the helicase catalytic cycle and could thus in principle be targeted for enzyme inhibition. In silico docking of a library of small molecules allowed us to identify a few selected compounds with high predicted affinity for the new site. Their activity against helicases from several flaviviruses was confirmed in in vitro helicase/enzymatic assays. The effect on the in vitro replication of flaviviruses was then evaluated. Results Ivermectin, a broadly used anti-helminthic drug, proved to be a highly potent inhibitor of YFV replication (EC50 values in the sub-nanomolar range). Moreover, ivermectin inhibited, although less efficiently, the replication of several other flaviviruses, i.e. dengue fever, Japanese encephalitis and tick-borne encephalitis viruses. Ivermectin exerts its effect at a timepoint that coincides with the onset of intracellular viral RNA synthesis, as expected for a molecule that specifically targets the viral helicase. Conclusions The well-tolerated drug ivermectin may hold great potential for treatment of YFV infections. Furthermore, structure-based optimization may result in analogues exerting potent activity against flaviviruses other than YFV. PMID:22535622

  2. New potent and selective inhibitors of anandamide reuptake with antispastic activity in a mouse model of multiple sclerosis.

    PubMed

    Ligresti, Alessia; Cascio, Maria Grazia; Pryce, Gareth; Kulasegram, Sanjitha; Beletskaya, Irina; De Petrocellis, Luciano; Saha, Bijali; Mahadevan, Anu; Visintin, Cristina; Wiley, Jenny L; Baker, David; Martin, Billy R; Razdan, Raj K; Di Marzo, Vincenzo

    2006-01-01

    We previously reported that the compound O-2093 is a selective inhibitor of the reuptake of the endocannabinoid anandamide (AEA). We have now re-examined the activity of O-2093 in vivo and synthesized four structural analogs (O-2247, O-2248, O-3246, and O-3262), whose activity was assessed in: (a) binding assays carried out with membranes from cells overexpressing the human CB(1) and CB(2) receptors; (b) assays of transient receptor potential of the vanilloid type-1 (TRPV1) channel functional activity (measurement of [Ca(2+)](i)); (c) [(14)C]AEA cellular uptake and hydrolysis assays in rat basophilic leukaemia (RBL-2H3) cells; (d) the mouse 'tetrad' tests (analgesia on a hot plate, immobility on a 'ring', rectal hypothermia and hypolocomotion in an open field); and (e) the limb spasticity test in chronic relapsing experimental allergic encephalomyelitis (CREAE) mice, a model of multiple sclerosis (MS). O-2093, either synthesized by us or commercially available, was inactive in the 'tetrad' up to a 20 mg kg(-1) dose (i.v.). Like O-2093, the other four compounds exhibited low affinity in CB(1) (K(i) from 1.3 to >10 microM) and CB(2) binding assays (1.310 microM), very low potency as fatty acid amide hydrolase (FAAH) inhibitors (IC(50)>25 microM) and were inactive in the 'tetrad' up to a 30 mg kg(-1) dose (i.v.). While O-2247 and O-2248 were poor inhibitors of [(14)C]AEA cellular uptake (IC(50)>40 microM), O-3246 and O-3262 were quite potent in this assay. O-3246, which exhibits only a very subtle structural difference with O-2093, is the most potent inhibitor of AEA uptake reported in vitro under our experimental conditions (IC(50)=1.4 microM) and is 12-fold more potent than O-2093. When injected intravenously O-3246 and O-3262, again like O-2093 and unlike O-2247 and O-2248, significantly inhibited limb spasticity in mice with CREAE. These data confirm the potential utility of selective

  3. New potent and selective inhibitors of anandamide reuptake with antispastic activity in a mouse model of multiple sclerosis

    PubMed Central

    Ligresti, Alessia; Cascio, Maria Grazia; Pryce, Gareth; Kulasegram, Sanjitha; Beletskaya, Irina; De Petrocellis, Luciano; Saha, Bijali; Mahadevan, Anu; Visintin, Cristina; Wiley, Jenny L; Baker, David; Martin, Billy R; Razdan, Raj K; Di Marzo, Vincenzo

    2005-01-01

    We previously reported that the compound O-2093 is a selective inhibitor of the reuptake of the endocannabinoid anandamide (AEA). We have now re-examined the activity of O-2093 in vivo and synthesized four structural analogs (O-2247, O-2248, O-3246, and O-3262), whose activity was assessed in: (a) binding assays carried out with membranes from cells overexpressing the human CB1 and CB2 receptors; (b) assays of transient receptor potential of the vanilloid type-1 (TRPV1) channel functional activity (measurement of [Ca2+]i); (c) [14C]AEA cellular uptake and hydrolysis assays in rat basophilic leukaemia (RBL-2H3) cells; (d) the mouse ‘tetrad' tests (analgesia on a hot plate, immobility on a ‘ring', rectal hypothermia and hypolocomotion in an open field); and (e) the limb spasticity test in chronic relapsing experimental allergic encephalomyelitis (CREAE) mice, a model of multiple sclerosis (MS). O-2093, either synthesized by us or commercially available, was inactive in the ‘tetrad' up to a 20 mg kg−1 dose (i.v.). Like O-2093, the other four compounds exhibited low affinity in CB1 (Ki from 1.3 to >10 μM) and CB2 binding assays (1.310 μM), very low potency as fatty acid amide hydrolase (FAAH) inhibitors (IC50>25 μM) and were inactive in the ‘tetrad' up to a 30 mg kg−1 dose (i.v.). While O-2247 and O-2248 were poor inhibitors of [14C]AEA cellular uptake (IC50>40 μM), O-3246 and O-3262 were quite potent in this assay. O-3246, which exhibits only a very subtle structural difference with O-2093, is the most potent inhibitor of AEA uptake reported in vitro under our experimental conditions (IC50=1.4 μM) and is 12-fold more potent than O-2093. When injected intravenously O-3246 and O-3262, again like O-2093 and unlike O-2247 and O-2248, significantly inhibited limb spasticity in mice with CREAE. These data confirm the potential utility of selective AEA uptake

  4. Inhibition of constitutive signal transducer and activator of transcription 3 activation by novel platinum complexes with potent antitumor activity.

    PubMed

    Turkson, James; Zhang, Shumin; Palmer, Jay; Kay, Heidi; Stanko, Joseph; Mora, Linda B; Sebti, Said; Yu, Hua; Jove, Richard

    2004-12-01

    DNA-alkylating agents that are platinum complexes induce apoptotic responses and have wide application in cancer therapy. The potential for platinum compounds to modulate signal transduction events that contribute to their therapeutic outcome has not been extensively examined. Among the signal transducer and activator of transcription (STAT) proteins, Stat3 activity is frequently up-regulated in many human tumors. Various lines of evidence have established a causal role for aberrant Stat3 activity in malignant transformation and provided validation for its targeting in the development of small-molecule inhibitors as novel cancer therapeutics. We report here that platinum-containing compounds disrupt Stat3 signaling and suppress its biological functions. The novel platinum (IV) compounds, CPA-1, CPA-7, and platinum (IV) tetrachloride block Stat3 activity in vitro at low micromolar concentrations. In malignant cells that harbor constitutively activated Stat3, CPA-1, CPA-7, and platinum (IV) tetrachloride inhibit cell growth and induce apoptosis in a manner that reflects the attenuation of persistent Stat3 activity. By contrast, cells that do not contain persistent Stat3 activity are marginally affected or are not affected by these compounds. Moreover, CPA-7 induces the regression of mouse CT26 colon tumor, which correlates with the abrogation of persistent Stat3 activity in tumors. Thus, the modulation of oncogenic signal transduction pathways, such as Stat3, may be one of the key molecular mechanisms for the antitumor effects of platinum (IV)-containing complexes.

  5. Histone deacetylase activators: N-acetylthioureas serve as highly potent and isozyme selective activators for human histone deacetylase-8 on a fluorescent substrate.

    PubMed

    Singh, Raushan K; Mandal, Tanmay; Balsubramanian, Narayanaganesh; Viaene, Tajae; Leedahl, Travis; Sule, Nitesh; Cook, Gregory; Srivastava, D K

    2011-10-01

    We report, for the first time, that certain N-acetylthiourea derivatives serve as highly potent and isozyme selective activators for the recombinant form of human histone deacetylase-8 in the assay system containing Fluor-de-Lys as a fluorescent substrate. The experimental data reveals that such activating feature is manifested via decrease in the K(m) value of the enzyme's substrate and increase in the catalytic turnover rate of the enzyme.

  6. Central domain of IL-33 is cleaved by mast cell proteases for potent activation of group-2 innate lymphoid cells

    PubMed Central

    Lefrançais, Emma; Duval, Anais; Mirey, Emilie; Roga, Stéphane; Espinosa, Eric; Cayrol, Corinne; Girard, Jean-Philippe

    2014-01-01

    Interleukin-33 (IL-33) is an alarmin cytokine from the IL-1 family. IL-33 activates many immune cell types expressing the interleukin 1 receptor-like 1 (IL1RL1) receptor ST2, including group-2 innate lymphoid cells (ILC2s, natural helper cells, nuocytes), the major producers of IL-5 and IL-13 during type-2 innate immune responses and allergic airway inflammation. IL-33 is likely to play a critical role in asthma because the IL33 and ST2/IL1RL1 genes have been reproducibly identified as major susceptibility loci in large-scale genome-wide association studies. A better understanding of the mechanisms regulating IL-33 activity is thus urgently needed. Here, we investigated the role of mast cells, critical effector cells in allergic disorders, known to interact with ILC2s in vivo. We found that serine proteases secreted by activated mast cells (chymase and tryptase) generate mature forms of IL-33 with potent activity on ILC2s. The major forms produced by mast cell proteases, IL-3395–270, IL-33107–270, and IL-33109–270, were 30-fold more potent than full-length human IL-331–270 for activation of ILC2s ex vivo. They induced a strong expansion of ILC2s and eosinophils in vivo, associated with elevated concentrations of IL-5 and IL-13. Murine IL-33 is also cleaved by mast cell tryptase, and a tryptase inhibitor reduced IL-33–dependent allergic airway inflammation in vivo. Our study identifies the central cleavage/activation domain of IL-33 (amino acids 66–111) as an important functional domain of the protein and suggests that interference with IL-33 cleavage and activation by mast cell and other inflammatory proteases could be useful to reduce IL-33–mediated responses in allergic asthma and other inflammatory diseases. PMID:25313073

  7. Design, synthesis, and structure-activity relationship studies of novel thioether pleuromutilin derivatives as potent antibacterial agents.

    PubMed

    Ling, Chenyu; Fu, Liqiang; Gao, Suo; Chu, Wenjing; Wang, Hui; Huang, Yanqin; Chen, Xiaoyan; Yang, Yushe

    2014-06-12

    A series of novel thioether pleuromutilin derivatives incorporating various heteroaromatic substituents into the C14 side chain have been reported. Structure-activity relationship (SAR) studies resulted in compounds 52 and 55 with the most potent in vitro antibacterial activity among the series (MIC = 0.031-0.063 μg/mL). Further optimization to overcome the poor water solubility of compound 55 resulted in compounds 87, 91, 109, and 110 possessing good in vitro antibacterial activity with increased hydrophilicity. Compound 114, the water-soluble phosphate prodrug of compound 52, was also prepared and evaluated. Among the derivatives, compound 110 showed moderate pharmacokinetic profiles and good in vivo efficacy in both MSSA and MRSA systemic infection models. Compound 110 was further evaluated in CYP450 inhibition assay and displayed intermediate in vitro inhibition of CYP3A4.

  8. Synthesis and Biological Evaluation of 3-Alkyl-1,5-Diaryl-1H-Pyrazoles as Rigid Analogues of Combretastatin A-4 with Potent Antiproliferative Activity

    PubMed Central

    Xu, Qile; Qi, Huan; Sun, Maolin; Zuo, Daiying; Jiang, Xuewei; Wen, Zhiyong; Wang, Zhiwei; Wu, Yingliang; Zhang, Weige

    2015-01-01

    A series of novel 3-alkyl-1,5-diaryl-1H-pyrazoles were synthesized as combretastatin A-4 (CA-4) analogues and evaluated for antiproliferative activity against three human cancer cell lines (SGC-7901, A549 and HT-1080). Most of the target compounds displayed moderate to potent antiproliferative activity, and 7k was found to be the most potent compound. Structure-activity relationships indicated that compounds with a trimethoxyphenyl A-ring at the N-1 position of the pyrazole skeleton were more potent than those with the A-ring at the C-5 position. Tubulin polymerization and immunostaining experiments revealed that 7k potently inhibited tubulin polymerization and disrupted tubulin microtubule dynamics in a manner similar to CA-4. Computational modelling demonstrated that the binding of 7k to the colchicine binding site on microtubules may involve a similar mode as CA-4. PMID:26061410

  9. Chemical or genetic Pin1 inhibition exerts potent anticancer activity against hepatocellular carcinoma by blocking multiple cancer-driving pathways

    PubMed Central

    Liao, Xin-Hua; Zhang, Arina Li; Zheng, Min; Li, Mei-Qing; Chen, Champ Peng; Xu, Huijuan; Chu, Qing-Song; Yang, Dayun; Lu, Wenxian; Tsai, Ting-Fen; Liu, Hekun; Zhou, Xiao Zhen; Lu, Kun Ping

    2017-01-01

    Hepatocellular carcinoma (HCC) is one of the most prevalent and malignant cancers with high inter- and intra-tumor heterogeneity. A central common signaling mechanism in cancer is proline-directed phosphorylation, which is further regulated by the unique proline isomerase Pin1. Pin1 is prevalently overexpressed in human cancers including ~70% of HCC, and promotes tumorigenesis by activating multiple cancer-driving pathways. However, it was challenging to evaluate the significance of targeting Pin1 in cancer treatment until the recent identification of all-trans retinoic acid (ATRA) as a Pin1 inhibitor. Here we systematically investigate functions of Pin1 and its inhibitor ATRA in the development and treatment of HCC. Pin1 knockdown potently inhibited HCC cell proliferation and tumor growth in mice. ATRA-induced Pin1 degradation inhibited the growth of HCC cells, although at a higher IC50 as compared with breast cancer cells, likely due to more active ATRA metabolism in liver cells. Indeed, inhibition of ATRA metabolism enhanced the sensitivity of HCC cells to ATRA. Moreover, slow-releasing ATRA potently and dose-dependently inhibited HCC growth in mice. Finally, chemical or genetic Pin1 ablation blocked multiple cancer-driving pathways simultaneously in HCC cells. Thus, targeting Pin1 offers a promising therapeutic approach to simultaneously stop multiple cancer-driving pathways in HCC. PMID:28262728

  10. Potent suppressive activity of chlorophyll a and b from green tea (Camellia sinensis) against tumor promotion in mouse skin.

    PubMed

    Higashi-Okai, K; Okai, Y

    1998-09-01

    Potent antigenotoxic and anti-tumor promoting activities of chlorophyll a from green tea (camellia sinensis) have been shown using in vitro cell culture experiments (Okai Y. et al. (1996) Mutation Res., 370, 11-17). In the present study, the authors analyzed in vivo effects of chlorophyll a and b from green tea on tumor promotion in mouse skin in the following ways. 1. When chlorophyll a and b from green tea were applied before each treatment by a tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on BALB/c mouse skin initiated by 7, 12-dimethylbenz [a] an-thracene (DMBA), they caused significant suppression in a dose-dependent manner against BALB/c mouse skin tumorigenesis. 2. Chlorophyll a and b showed significant suppressive effects against TPA-induced inflammatory reaction such as edema formation in BALB/c mouse ear skin in a dose-dependent fashion. These results suggest that chlorophyll a and b possess potent suppressive activities against tumor promotion in mouse skin.

  11. The Spider Venom Peptide Lycosin-II Has Potent Antimicrobial Activity against Clinically Isolated Bacteria

    PubMed Central

    Wang, Yongjun; Wang, Ling; Yang, Huali; Xiao, Haoliang; Farooq, Athar; Liu, Zhonghua; Hu, Min; Shi, Xiaoliu

    2016-01-01

    Antimicrobial peptides have been accepted as excellent candidates for developing novel antibiotics against drug-resistant bacteria. Recent studies indicate that spider venoms are the source for the identification of novel antimicrobial peptides. In the present study, we isolated and characterized an antibacterial peptide named lycosin-II from the venom of the spider Lycosa singoriensis. It contains 21 amino acid residue lacking cysteine residues and forms a typical linear amphipathic and cationic α-helical conformation. Lycosin-II displays potent bacteriostatic effect on the tested drug-resistant bacterial strains isolated from hospital patients, including multidrug-resistant A. baumannii, which has presented a huge challenge for the infection therapy. The inhibitory ability of lycosin-II might derive from its binding to cell membrane, because Mg2+ could compete with the binding sites to reduce the bacteriostatic potency of lycosin-II. Our data suggest that lycosin-II might be a lead in the development of novel antibiotics for curing drug-resistant bacterial infections. PMID:27128941

  12. Synthesis and structure-activity relationships of novel arylpiperazines as potent antagonists of α1-adrenoceptor.

    PubMed

    Silva, Renata Oliveira; de Oliveira, Andressa Souza; Nunes Lemes, Laís Flávia; de Camargo Nascente, Luciana; Coelho do Nascimento Nogueira, Patrícia; Silveira, Edilberto R; Brand, Guilherme D; Vistoli, Giulio; Cilia, Antonio; Poggesi, Elena; Buccioni, Michela; Marucci, Gabriella; Bolognesi, Maria Laura; Romeiro, Luiz Antonio Soares

    2016-10-21

    Arylpiperazines 2-11 were synthesized, and their biological profiles at α1-adrenergic receptors (α1-ARs) assessed by binding assays in CHO cells expressing human cloned subtypes and by functional experiments in isolated rat vas deferens (α1A), spleen (α1B), and aorta (α1D). Modifications at the 1,3-benzodioxole and phenyl phamacophoric units resulted in the identification of a number of potent compounds (moderately selective with respect to the α1b-AR), in binding experiments. Notably, compound 7 (LDT451) showed a subnanomolar pKi of 9.41 towards α1a-AR. An encouragingly lower α1B-potency was a general trend for all the series of compounds, which showed α1A/D over α1B selectivity in functional assays. If adequately optimized, such peculiar selectivity could have relevance for a potential LUTS/BPH therapeutic application. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Selective and potent Akt inhibition triggers anti-myeloma activities and enhances fatal endoplasmic reticulum stress induced by proteasome inhibition.

    PubMed

    Mimura, Naoya; Hideshima, Teru; Shimomura, Toshiyasu; Suzuki, Rikio; Ohguchi, Hiroto; Rizq, Ola; Kikuchi, Shohei; Yoshida, Yasuhiro; Cottini, Francesca; Jakubikova, Jana; Cirstea, Diana; Gorgun, Gullu; Minami, Jiro; Tai, Yu-Tzu; Richardson, Paul G; Utsugi, Teruhiro; Iwama, Atsushi; Anderson, Kenneth C

    2014-08-15

    The PI3K/Akt pathway plays a crucial role in the pathogenesis of multiple myeloma (MM) in the bone marrow (BM) milieu. However, efficacy of selective and potent Akt inhibition has not yet been fully elucidated. In this study, we, therefore, examined the biologic impact of selective and potent Akt inhibition by a novel allosteric inhibitor TAS-117. TAS-117 induced significant growth inhibition, associated with downregulation of phosphorylated Akt (p-Akt), selectively in MM cell lines with high baseline p-Akt. Cytotoxicity of TAS-117 was also observed in patient MM cells, but not in normal peripheral blood mononuclear cells. Importantly, TAS-117 induced significant cytotoxicity in MM cells even in the presence of BM stromal cells, associated with inhibition of IL6 secretion. Oral administration of TAS-117 significantly inhibited human MM cell growth in murine xenograft models. TAS-117 triggered apoptosis and autophagy, as well as induction of endoplasmic reticulum (ER) stress response with minimal expression of C/EBP homologous protein (CHOP), a fatal ER stress marker. Importantly, TAS-117 enhanced bortezomib-induced cytotoxicity, associated with increased CHOP and PARP cleavage and blockade of bortezomib-induced p-Akt, suggesting that TAS-117 augments bortezomib-induced ER stress and apoptotic signaling. Carfilzomib-induced cytotoxicity was similarly enhanced by TAS-117. Importantly, TAS-117 enhanced bortezomib-induced cytotoxicity in vivo, associated with prolonged host survival. Our results show that selective and potent Akt inhibition by TAS-117 triggers anti-MM activities in vitro and in vivo, as well as enhances cytotoxicity of proteasome inhibition, providing the preclinical framework for clinical evaluation of selective Akt inhibitors, alone and in combination with proteasome inhibitors in MM. ©2014 American Association for Cancer Research.

  14. Pharmacological profile of the abeorphine 201-678, a potent orally active and long lasting dopamine agonist

    SciTech Connect

    Jaton, A.L.; Giger, R.K.A.; Vigouret, J.M.; Enz, A.; Frick, W.; Closse, A.; Markstein, R.

    1986-01-13

    The central dopaminergic effects of an abeorphine derivative 201-678 were compared to those of apomorphine and bromocriptine in different model systems. After oral administration, this compound induced contralateral turning in rats with 6-hydroxydopamine induced nigral lesions and exhibited strong anti-akinetic properties in rats with 6-hydroxydopamine induced hypothalamic lesions. It decreased dopamine metabolism in striatum and cortex, but did not modify noradrenaline and serotonin metabolism in the rat brain. 201-678 counteracted the in vivo increase of tyrosine hydroxylase activity induced by ..gamma..-butyrolactone. In vitro it stimulated DA-sensitive adenylate cyclase and inhibited acetylcholine release from rat striatal slices. This compound had high affinity for /sup 3/H-dopamine and /sup 3/H-clonidine binding sites. These results indicate that 201-678 is a potent, orally active dopamine agonist with a long duration of action. Furthermore it appears more selective than other dopaminergic drugs. 29 references, 5 figures, 3 tables.

  15. (-)-Englerin A is a potent and selective activator of TRPC4 and TRPC5 calcium channels.

    PubMed

    Akbulut, Yasemin; Gaunt, Hannah J; Muraki, Katsuhiko; Ludlow, Melanie J; Amer, Mohamed S; Bruns, Alexander; Vasudev, Naveen S; Radtke, Lea; Willot, Matthieu; Hahn, Sven; Seitz, Tobias; Ziegler, Slava; Christmann, Mathias; Beech, David J; Waldmann, Herbert

    2015-03-16

    Current therapies for common types of cancer such as renal cell cancer are often ineffective and unspecific, and novel pharmacological targets and approaches are in high demand. Here we show the unexpected possibility for the rapid and selective killing of renal cancer cells through activation of calcium-permeable nonselective transient receptor potential canonical (TRPC) calcium channels by the sesquiterpene (-)-englerin A. This compound was found to be a highly efficient, fast-acting, potent, selective, and direct stimulator of TRPC4 and TRPC5 channels. TRPC4/5 activation through a high-affinity extracellular (-)-englerin A binding site may open up novel opportunities for drug discovery aimed at renal cancer.

  16. Design, synthesis and molecular docking of α,β-unsaturated cyclohexanone analogous of curcumin as potent EGFR inhibitors with antiproliferative activity.

    PubMed

    Xu, Yun-Yun; Cao, Yi; Ma, Hailkuo; Li, Huan-Qiu; Ao, Gui-Zhen

    2013-01-15

    A type of novel α,β-unsaturated cyclohexanone analogous, which designed based on the curcumin core structure, have been discovered as potential EGFR inhibitors. These compounds exhibit potent antiproliferative activity in two human tumor cell lines (Hep G2 and B16-F10). Among them, compounds I(3) and I(12) displayed the most potent EGFR inhibitory activity (IC(50) = 0.43 μM and 1.54 μM, respectively). Molecular docking of I(12) into EGFR TK active site was also performed. This inhibitor nicely fitting the active site might well explain its excellent inhibitory activity.

  17. Rational design, synthesis and preliminary antitumor activity evaluation of a chlorambucil derivative with potent DNA/HDAC dual-targeting inhibitory activity.

    PubMed

    Xie, Rui; Li, Yan; Tang, Pingwah; Yuan, Qipeng

    2017-09-15

    Histone deacetylases (HDACs) play a pivotal role not only in gene expression but also in DNA repair. Herein, we report the successful design, synthesis and evaluation of a chlorambucil derivative named vorambucil with a hydroxamic acid tail as a DNA/HDAC dual-targeting inhibitor. Vorambucil obtained both potent DNA and HDACs inhibitory activities. Molecular docking results supported the initial pharmacophoric hypothesis and rationalized the potent inhibitory activity of vorambucil against HDAC1, HDAC2 and HDAC6. Vorambucil showed potent antiproliferative activity against all the test four cancer cell lines with IC50 values of as low as 3.2-6.2μM and exhibited 5.0-18.3-fold enhanced antiproliferative activity than chlorambucil. Vorambucil also significantly inhibits colony formation of A375 cancer cells. Further investigation showed that vorambucil remarkably induced apoptosis and arrested the cell cycle of A375 cells at G2/M phase. Vorambucil could be a promising candidate and a useful tool to elucidate the role of those DNA/HDAC dual-targeting inhibitors for cancer therapy. Copyright © 2017. Published by Elsevier Ltd.

  18. The cyclotide cycloviolacin O2 from Viola odorata has potent bactericidal activity against Gram-negative bacteria.

    PubMed

    Pränting, Maria; Lööv, Camilla; Burman, Robert; Göransson, Ulf; Andersson, Dan I

    2010-09-01

    To determine the antibacterial activity of small cyclic plant proteins, i.e. cyclotides, and the importance of the surface exposed charged residues for activity. Prototypic cyclotides, including the Möbius kalata B1 and the bracelet cycloviolacin O2 (cyO2), were isolated using reversed-phase HPLC. Initial activity screenings were conducted using radial diffusion assays (RDAs) and MIC assays with Salmonella enterica serovar Typhimurium LT2, Escherichia coli and Staphylococcus aureus as test strains. For the most active peptide, cyO2, time-kill kinetics was determined in sodium phosphate buffer (containing 0.03% trypticase soy broth) against several Gram-negative and Gram-positive bacterial species. Charged residues in cyO2 were chemically modified and activity was determined in time-kill assays. CyO2 was the most active cyclotide and efficiently inhibited the growth of S. enterica serovar Typhimurium LT2 and E. coli in RDAs and MIC assays, while the other peptides were less active. In time-kill assays, cyO2 also had bactericidal activity against the Gram-negative species Klebsiella pneumoniae and Pseudomonas aeruginosa. In contrast, none of the cyclotides had high activity against S. aureus. Chemical masking of the charged Glu and Lys residues in cyO2 caused a near total loss of activity against Salmonella, while masking Arg caused a less pronounced activity reduction. CyO2 is a cyclotide with potent activity against Gram-negative bacteria. The charged residues in cyO2 are all required for optimum antibacterial activity. In combination with its previously demonstrated cytotoxic activity against cancer cells and the general stability of cyclotides, cyO2 provides a promising scaffold for future drug design.

  19. Antiviral Activity of Bictegravir (GS-9883), a Novel Potent HIV-1 Integrase Strand Transfer Inhibitor with an Improved Resistance Profile

    PubMed Central

    Tsiang, Manuel; Jones, Gregg S.; Goldsmith, Joshua; Mulato, Andrew; Hansen, Derek; Kan, Elaine; Tsai, Luong; Bam, Rujuta A.; Stepan, George; Stray, Kirsten M.; Niedziela-Majka, Anita; Yant, Stephen R.; Yu, Helen; Kukolj, George; Cihlar, Tomas; Lazerwith, Scott E.; Jin, Haolun

    2016-01-01

    Bictegravir (BIC; GS-9883), a novel, potent, once-daily, unboosted inhibitor of HIV-1 integrase (IN), specifically targets IN strand transfer activity (50% inhibitory concentration [IC50] of 7.5 ± 0.3 nM) and HIV-1 integration in cells. BIC exhibits potent and selective in vitro antiretroviral activity in both T-cell lines and primary human T lymphocytes, with 50% effective concentrations ranging from 1.5 to 2.4 nM and selectivity indices up to 8,700 relative to cytotoxicity. BIC exhibits synergistic in vitro antiviral effects in pairwise combinations with tenofovir alafenamide, emtricitabine, or darunavir and maintains potent antiviral activity against HIV-1 variants resistant to other classes of antiretrovirals. BIC displayed an in vitro resistance profile that was markedly improved compared to the integrase strand transfer inhibitors (INSTIs) raltegravir (RAL) and elvitegravir (EVG), and comparable to that of dolutegravir (DTG), against nine INSTI-resistant site-directed HIV-1 mutants. BIC displayed statistically improved antiviral activity relative to EVG, RAL, and DTG against a panel of 47 patient-derived HIV-1 isolates with high-level INSTI resistance; 13 of 47 tested isolates exhibited >2-fold lower resistance to BIC than DTG. In dose-escalation experiments conducted in vitro, BIC and DTG exhibited higher barriers to resistance than EVG, selecting for HIV-1 variants with reduced phenotypic susceptibility at days 71, 87, and 20, respectively. A recombinant virus with the BIC-selected M50I/R263K dual mutations in IN exhibited only 2.8-fold reduced susceptibility to BIC compared to wild-type virus. All BIC-selected variants exhibited low to intermediate levels of cross-resistance to RAL, DTG, and EVG (<8-fold) but remained susceptible to other classes of antiretrovirals. A high barrier to in vitro resistance emergence for both BIC and DTG was also observed in viral breakthrough studies in the presence of constant clinically relevant drug concentrations. The

  20. A Combined Pharmacodynamic Quantitative and Qualitative Model Reveals the Potent Activity of Daptomycin and Delafloxacin against Staphylococcus aureus Biofilms

    PubMed Central

    Bauer, Julia; Siala, Wafi; Tulkens, Paul M.

    2013-01-01

    Biofilms are associated with persistence of Staphylococcus aureus infections and therapeutic failures. Our aim was to set up a pharmacodynamic model comparing antibiotic activities against biofilms and examining in parallel their effects on viability and biofilm mass. Biofilms of S. aureus ATCC 25923 (methicillin-sensitive S. aureus [MSSA]) or ATCC 33591 (methicillin-resistant S. aureus [MRSA]) were obtained by culture in 96-well plates for 6 h/24 h. Antibiotic activities were assessed after 24/48 h of exposure to concentrations ranging from 0.5 to 512 times the MIC. Biofilm mass and bacterial viability were quantified using crystal violet and the redox indicator resazurin. Biofilms stained with Live/Dead probes were observed by using confocal microscopy. Concentration-effect curves fitted sigmoidal regressions, with a 50% reduction toward both matrix and viability obtained at sub-MIC or low multiples of MICs against young biofilms for all antibiotics tested. Against mature biofilms, maximal efficacies and potencies were reduced, with none of the antibiotics being able to completely destroy the matrix. Delafloxacin and daptomycin were the most potent, reducing viability by more than 50% at clinically achievable concentrations against both strains, as well as reducing biofilm depth, as observed in confocal microscopy. Rifampin, tigecycline, and moxifloxacin were effective against mature MRSA biofilms, while oxacillin demonstrated activity against MSSA. Fusidic acid, vancomycin, and linezolid were less potent overall. Antibiotic activity depends on biofilm maturity and bacterial strain. The pharmacodynamic model developed allows ranking of antibiotics with respect to efficacy and potency at clinically achievable concentrations and highlights the potential utility of daptomycin and delafloxacin for the treatment of biofilm-related infections. PMID:23571532

  1. A Novel Immunomodulatory Hemocyanin from the Limpet Fissurella latimarginata Promotes Potent Anti-Tumor Activity in Melanoma

    PubMed Central

    Arancibia, Sergio; Espinoza, Cecilia; Salazar, Fabián; Del Campo, Miguel; Tampe, Ricardo; Zhong, Ta-Ying; De Ioannes, Pablo; Moltedo, Bruno; Ferreira, Jorge; Lavelle, Ed C.; Manubens, Augusto; De Ioannes, Alfredo E.; Becker, María Inés

    2014-01-01

    Hemocyanins, the huge oxygen-transporting glycoproteins of some mollusks, are used as immunomodulatory proteins with proven anti-cancer properties. The biodiversity of hemocyanins has promoted interest in identifying new anti-cancer candidates with improved immunological properties. Hemocyanins promote Th1 responses without known side effects, which make them ideal for long-term sustained treatment of cancer. In this study, we evaluated a novel hemocyanin from the limpet/gastropod Fissurella latimarginata (FLH). This protein has the typical hollow, cylindrical structure of other known hemocyanins, such as the keyhole limpet hemocyanin (KLH) and the Concholepas hemocyanin (CCH). FLH, like the KLH isoforms, is composed of a single type of polypeptide with exposed N- and O-linked oligosaccharides. However, its immunogenicity was significantly greater than that of KLH and CCH, as FLH induced a stronger humoral immune response and had more potent anti-tumor activity, delaying tumor growth and increasing the survival of mice challenged with B16F10 melanoma cells, in prophylactic and therapeutic settings. Additionally, FLH-treated mice demonstrated increased IFN-γ production and higher numbers of tumor-infiltrating CD4+ lymphocytes. Furthermore, in vitro assays demonstrated that FLH, but not CCH or KLH, stimulated the rapid production of pro-inflammatory cytokines (IL-6, IL-12, IL-23 and TNF-α) by dendritic cells, triggering a pro-inflammatory milieu that may explain its enhanced immunological activity. Moreover, this effect was abolished when deglycosylated FLH was used, suggesting that carbohydrates play a crucial role in the innate immune recognition of this protein. Altogether, our data demonstrate that FLH possesses increased anti-tumor activity in part because it activates a more potent innate immune response in comparison to other known hemocyanins. In conclusion, FLH is a potential new marine adjuvant for immunization and possible cancer immunotherapy. PMID

  2. PM01183, a new DNA minor groove covalent binder with potent in vitro and in vivo anti-tumour activity

    PubMed Central

    Leal, JFM; Martínez-Díez, M; García-Hernández, V; Moneo, V; Domingo, A; Bueren-Calabuig, JA; Negri, A; Gago, F; Guillén-Navarro, MJ; Avilés, P; Cuevas, C; García-Fernández, LF; Galmarini, CM

    2010-01-01

    BACKGROUND AND PURPOSE PM01183 is a new synthetic tetrahydroisoquinoline alkaloid that is currently in phase I clinical development for the treatment of solid tumours. In this study we have characterized the interactions of PM01183 with selected DNA molecules of defined sequence and its in vitro and in vivo cytotoxicity. EXPERIMENTAL APPROACH DNA binding characteristics of PM01183 were studied using electrophoretic mobility shift assays, fluorescence-based melting kinetic experiments and computational modelling methods. Its mechanism of action was investigated using flow cytometry, Western blot analysis and fluorescent microscopy. In vitro anti-tumour activity was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and the in vivo activity utilized several human cancer models. KEY RESULTS Electrophoretic mobility shift assays demonstrated that PM01183 bound to DNA. Fluorescence-based thermal denaturation experiments showed that the most favourable DNA triplets providing a central guanine for covalent adduct formation are AGC, CGG, AGG and TGG. These binding preferences could be rationalized using molecular modelling. PM01183–DNA adducts in living cells give rise to double-strand breaks, triggering S-phase accumulation and apoptosis. The potent cytotoxic activity of PM01183 was ascertained in a 23-cell line panel with a mean GI50 value of 2.7 nM. In four murine xenograft models of human cancer, PM01183 inhibited tumour growth significantly with no weight loss of treated animals. CONCLUSIONS AND IMPLICATIONS PM01183 is shown to bind to selected DNA sequences and promoted apoptosis by inducing double-strand breaks at nanomolar concentrations. The potent anti-tumour activity of PM01183 in several murine models of human cancer supports its development as a novel anti-neoplastic agent. PMID:20977459

  3. Thusin, a Novel Two-Component Lantibiotic with Potent Antimicrobial Activity against Several Gram-Positive Pathogens

    PubMed Central

    Xin, Bingyue; Zheng, Jinshui; Liu, Hualin; Li, Junhua; Ruan, Lifang; Peng, Donghai; Sajid, Muhammad; Sun, Ming

    2016-01-01

    Due to the rapidly increasing prevalence of multidrug-resistant bacterial strains, the need for new antimicrobial drugs to treat infections has become urgent. Bacteriocins, which are antimicrobial peptides of bacterial origin, are considered potential alternatives to conventional antibiotics and have attracted widespread attention in recent years. Among these bacteriocins, lantibiotics, especially two-component lantibiotics, exhibit potent antimicrobial activity against some clinically relevant Gram-positive pathogens and have potential applications in the pharmaceutical industry. In this study, we characterized a novel two-component lantibiotic termed thusin that consists of Thsα, Thsβ, and Thsβ' (mutation of Thsβ, A14G) and that was isolated from a B. thuringiensis strain BGSC 4BT1. Thsα and Thsβ (or Thsβ') exhibit optimal antimicrobial activity at a 1:1 ratio and act sequentially to affect target cells, and they are all highly thermostable (100°C for 30 min) and pH tolerant (pH 2.0 to 9.0). Thusin shows remarkable efficacy against all tested Gram-positive bacteria and greater activities than two known lantibiotics thuricin 4A-4 and ticin A4, and one antibiotic vancomycin against various bacterial pathogens (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus (MRSA), Staphylococcus sciuri, Enterococcus faecalis, and Streptococcus pneumoniae). Moreover, thusin is also able to inhibit the outgrowth of B. cereus spores. The potent antimicrobial activity of thusin against some Gram-positive pathogens indicates that it has potential for the development of new drugs. PMID:27486447

  4. Identification of Tetraazacyclic Compounds as Novel Potent Inhibitors Antagonizing RORγt Activity and Suppressing Th17 Cell Differentiation

    PubMed Central

    Ding, Qingfeng; Zhao, Mei; Yu, Bolan; Bai, Chuan; Huang, Zhaofeng

    2015-01-01

    CD4+ T-helper cells that produce interleukin-17 (Th17 cells) are characterized as pathological T-helper cells in autoimmune diseases. Differentiation of human and mouse Th17 cells requires a key transcription regulator, retinoic acid receptor-related orphan receptor γt (RORγt), which is a potential therapeutic target for autoimmune diseases. To develop a therapeutic agent for Th17-mediated autoimmune diseases, we have established a high-throughput screening (HTS) assay for candidate screening, in which the luciferase activity in RORγt-LBD positive and negative Jurkat cells were analyzed to evaluate induction of RORγt activity by compounds. This technique was applied to screen a commercially-available drug-like chemical compound library (Enamine) which contains 20155 compounds. The screening identified 17 compounds that can inhibit RORγt function in the HTS screen system. Of these, three tetraazacyclic compounds can potently inhibit RORγt activity, and suppress Th17 differentiation and IL-17 production. These three candidate compounds could significantly attenuate the expression of the Il17a by 65%- 90%, and inhibit IL-17A secretion by 47%, 63%, and 74%, respectively. These compounds also exhibited a potent anti-RORγt activity, with EC50 values of 0.25 μM, 0.67 μM and 2.6 μM, respectively. Our data demonstrated the feasibility of targeting the RORγt to inhibit Th17 cell differentiation and function with these tetraazacyclic compounds, and the potential to improve the structure of these compounds for autoimmune diseases therapeutics. PMID:26368822

  5. Design and synthesis of a tetrahydroisoquinoline-based hydroxamate derivative (ZYJ-34v), an oral active histone deacetylase inhibitor with potent antitumor activity.

    PubMed

    Zhang, Yingjie; Liu, Chunxi; Chou, C James; Wang, Xuejian; Jia, Yuping; Xu, Wenfang

    2013-08-01

    In our previous study, we developed a novel series of tetrahydroisoquinoline-based hydroxamic acid derivatives as histone deacetylase inhibitors (Bioorg Med Chem, 2010, 18, 1761-1772; J Med Chem, 2011, 54, 2823-2838), among which, compound ZYJ-34c (1) was identified and validated as the most potent one with marked in vitro and in vivo antitumor potency (J Med Chem, 2011, 54, 5532-5539.). Herein, further modification in 1 afforded another oral active analog ZYJ-34v (2) with simplified structure and lower molecular weight. Biological evaluation of compound 2 showed efficacious inhibition against histone deacetylase 1, 2, 3, and 6, which was confirmed by Western blot analysis results. Most importantly, compound 2 exhibited similar even more potent in vitro and in vivo antitumor activities relative to the approved histone deacetylase inhibitor SAHA.

  6. Potent DNA strand annealing activity associated with mouse Mcm2∼7 heterohexameric complex

    PubMed Central

    Masai, Hisao

    2017-01-01

    Abstract Mini-chromosome maintenance (Mcm) is a central component for DNA unwinding reaction during eukaryotic DNA replication. Mcm2∼7, each containing a conserved ATPase motif, form a six subunit-heterohexamer. Although the reconstituted Mcm2∼7–Cdc45–GINS (CMG) complex displays DNA unwinding activity, the Mcm2∼7 complex does not generally exhibit helicase activity under a normal assay condition. We detected a strong DNA strand annealing activity in the purified mouse Mcm2∼7 heterohexamer, which promotes rapid reassociation of displaced complementary single-stranded DNAs, suggesting a potential cause for its inability to exhibit DNA helicase activity. Indeed, DNA unwinding activity of Mcm2∼7 could be detected in the presence of a single-stranded DNA that is complementary to the displaced strand, which would prevent its reannealing to the template. ATPase-deficient mutations in Mcm2, 4, 5 and 6 subunits inactivated the annealing activity, while those in Mcm2 and 5 subunits alone did not. The annealing activity of Mcm2∼7 does not require Mg2+ and ATP, and is adversely inhibited by the presence of high concentration of Mg2+ and ATP while activated by similar concentrations of ADP. Our findings show that the DNA helicase activity of Mcm2∼7 may be masked by its unexpectedly strong annealing activity, and suggest potential physiological roles of strand annealing activity of Mcm during replication stress responses. PMID:28449043

  7. Evaluation of a protease activation mutant of Sendai virus as a potent live vaccine.

    PubMed

    Maru, M; Haraguchi, M; Sato, K; Hotta, H; Homma, M

    1992-01-01

    A protease activation mutant of Sendai virus, TR-5, was investigated as a candidate for a live vaccine. Vaccination with TR-5 which had been activated by chymotrypsin beforehand (active TR-5) elicited protective immunity against otherwise lethal challenge infection with wild-type Sendai virus in DBA/2, C3H and ICR strains of mice. Less of the active TR-5 was required to confer protection on mice compared with an ordinary ether-inactivated Sendai virus vaccine (split vaccine). The protective immunity elicited by TR-5 lasted longer and the booster effect was more prominent compared to the split vaccine. No seroconversion was observed with contact mice when housed in a cage with mice vaccinated with the active TR-5. The overall results show that the active TR-5 is an effective and safe live vaccine of Sendai virus in mice.

  8. 2-Arylindoles: a privileged molecular scaffold with potent, broad-ranging pharmacological activity.

    PubMed

    Lal, S; Snape, T J

    2012-01-01

    Privileged structures bind to multiple receptors with high affinity, thus aiding the development of novel biologically active compounds. Indoles are classed as privileged structures, and as a result of the indole nucleus being present in a broad range of biologically active molecules, it has been suggested that indoles probably represent the most important of all structural classes in drug discovery. Amongst the indole class of compounds is a particular subset - 2-arylindoles - which appear to be a most promising lead for drug development. This review summarises the wide-ranging activities of 2-arylindoles and some of their important biological activities reported in the literature over the past two decades.

  9. Characterization of SR 121463A, a highly potent and selective, orally active vasopressin V2 receptor antagonist.

    PubMed Central

    Serradeil-Le Gal, C; Lacour, C; Valette, G; Garcia, G; Foulon, L; Galindo, G; Bankir, L; Pouzet, B; Guillon, G; Barberis, C; Chicot, D; Jard, S; Vilain, P; Garcia, C; Marty, E; Raufaste, D; Brossard, G; Nisato, D; Maffrand, J P; Le Fur, G

    1996-01-01

    SR 121463A, a potent and selective, orally active, nonpeptide vasopressin V2 receptor antagonist, has been characterized in several in vitro and in vivo models. This compound displayed highly competitive and selective affinity for V2 receptors in rat, bovine and human kidney (0.6 < or = Ki [nM] < or = 4.1). In this latter preparation, SR 121463A potently antagonized arginine vasopressin (AVP)-stimulated adenylyl cyclase activity (Ki = 0.26+/-0.04 nM) without any intrinsic agonistic effect. In autoradiographic experiments performed in rat kidney sections, SR 121463A displaced [3H]AVP labeling especially in the medullo-papillary region and confirmed that it is a suitable tool for mapping V2 receptors. In comparison, the nonpeptide V2 antagonist, OPC-31260, showed much lower affinity for animal and human renal V2 receptors and lower efficacy to inhibit vasopressin-stimulated adenylyl cyclase (Ki in the 10 nanomolar range). Moreover, OPC-31260 exhibited a poor V2 selectivity profile and can be considered as a V2/V1a ligand. In normally hydrated conscious rats, SR 121463A induced powerful aquaresis after intravenous (0.003-0.3 mg/kg) or oral (0.03-10 mg/kg) administration. The effect was dose-dependent and lasted about 6 hours at the dose of 3 mg/kg p.o. OPC-31260 had a similar aquaretic profile but with markedly lower oral efficacy. The action of SR 121463A was purely aquaretic with no changes in urine Na+ and K+ excretions unlike that of known diuretic agents such as furosemide or hydrochlorothiazide. In addition, no antidiuretic properties have been detected with SR 121463A in vasopressin-deficient Brattleboro rats. Thus, SR 121463A is the most potent and selective, orally active V2 antagonist yet described and could be a powerful tool for exploring V2 receptors and the therapeutical usefulness of V2 blocker aquaretic agents in water-retaining diseases. PMID:8981918

  10. Electrophilic peroxisome proliferator-activated receptor-gamma ligands have potent antifibrotic effects in human lung fibroblasts.

    PubMed

    Ferguson, Heather E; Kulkarni, Ajit; Lehmann, Geniece M; Garcia-Bates, Tatiana M; Thatcher, Thomas H; Huxlin, Krystel R; Phipps, Richard P; Sime, Patricia J

    2009-12-01

    Pulmonary fibrosis is a progressive scarring disease with no effective treatment. Transforming growth factor (TGF)-beta is up-regulated in fibrotic diseases, where it stimulates differentiation of fibroblasts to myofibroblasts and production of excess extracellular matrix. Peroxisome proliferator-activated receptor (PPAR) gamma is a transcription factor that regulates adipogenesis, insulin sensitization, and inflammation. We report here that a novel PPARgamma ligand, 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO), is a potent inhibitor of TGF-beta-stimulated differentiation of human lung fibroblasts to myofibroblasts, and suppresses up-regulation of alpha-smooth muscle actin, fibronectin, collagen, and the novel myofibroblast marker, calponin. The inhibitory concentration causing a 50% decrease in aSMA for CDDO was 20-fold lower than the endogenous PPARgamma ligand, 15-deoxy-Delta(12,14)-prostaglandin J(2) (15 d-PGJ(2)), and 400-fold lower than the synthetic ligand, rosiglitazone. Pharmacologic and genetic approaches were used to demonstrate that CDDO mediates its activity via a PPARgamma-independent pathway. CDDO and 15 d-PGJ(2) contain an alpha/beta unsaturated ketone, which acts as an electrophilic center that can form covalent bonds with cellular proteins. Prostaglandin A(1) and diphenyl diselenide, both strong electrophiles, also inhibit myofibroblast differentiation, but a structural analog of 15 d-PGJ(2) lacking the electrophilic center is much less potent. CDDO does not alter TGF-beta-induced Smad or AP-1 signaling, but does inhibit acetylation of CREB binding protein/p300, a critical coactivator in the transcriptional regulation of TGF-beta-responsive genes. Overall, these data indicate that certain PPARgamma ligands, and other small molecules with electrophilic centers, are potent inhibitors of critical TGF-beta-mediated profibrogenic activities through pathways independent of PPARgamma. As the inhibitory concentration causing a 50% decrease in a

  11. Development of GoSlo-SR-5-69, a potent activator of large conductance Ca2+-activated K+ (BK) channels.

    PubMed

    Roy, Subhrangsu; Large, Roddy J; Akande, Adebola Morayo; Kshatri, Aravind; Webb, Tim I; Domene, Carmen; Sergeant, Gerard P; McHale, Noel G; Thornbury, Keith D; Hollywood, Mark A

    2014-03-21

    We have designed, synthesised and characterised the effects of a number of novel anthraquinone derivatives and assessed their effects on large conductance, Ca(2+) activated K(+) (BK) channels recorded from rabbit bladder smooth muscle cells using the excised, inside/out configuration of the patch clamp technique. These compounds are members of the GoSlo-SR family of compounds, which potently open BK channels and shift the voltage required for half maximal activation (V1/2) negatively. The efficacy of the anilinoanthraquinone derivatives was enhanced when the size of ring D was increased, since the cyclopentane and cyclohexane derivatives shifted the V1/2, by -24 ± 6 mV and -54 ± 8 mV, respectively, whereas the cycloheptane and cyclooctane derivatives shifted the V1/2 by -61 ± 6 mV and -106 ± 6 mV. To examine if a combination of hydrophobicity and steric bulking of this region further enhanced their ability to open BK channels, we synthesised a number of naphthalene and tetrahydro-naphthalene derivatives. The tetrahydro-2-naphthalene derivative GoSlo-SR-5-69 was the most potent and efficacious of the series since it was able to shift the activation V1/2 by greater than -100 mV when applied at a concentration of 1 μM and had an EC50 of 251 nM, making it one of the most potent and efficacious BK channel openers synthesised to date.

  12. Potent Activity of Ponatinib (AP24534) in Models of FLT3-Driven Acute Myeloid Leukemia and Other Hematologic Malignancies

    PubMed Central

    Gozgit, Joseph M.; Wong, Matthew J.; Wardwell, Scott; Tyner, Jeffrey W.; Loriaux, Marc M.; Mohemmad, Qurish K.; Narasimhan, Narayana I.; Shakespeare, William C.; Wang, Frank; Druker, Brian J.; Clackson, Tim; Rivera, Victor M.

    2011-01-01

    Ponatinib (AP24534) is a novel multitargeted kinase inhibitor that potently inhibits native and mutant BCR-ABL at clinically achievable drug levels. Ponatinib also has in vitro inhibitory activity against a discrete set of kinases implicated in the pathogenesis of other hematologic malignancies, including FLT3, KIT, fibroblast growth factor receptor 1 (FGFR1), and platelet derived growth factor receptor α (PDGFRα). Here, using leukemic cell lines containing activated forms of each of these receptors, we show that ponatinib potently inhibits receptor phosphorylation and cellular proliferation with IC50 values comparable to those required for inhibition of BCR-ABL (0.3 to 20 nmol/L). The activity of ponatinib against the FLT3-ITD mutant, found in up to 30% of acute myeloid leukemia (AML) patients, was particularly notable. In MV4-11 (FLT3-ITD+/+) but not RS4;11 (FLT3-ITD−/−) AML cells, ponatinib inhibited FLT3 signaling and induced apoptosis at concentrations of less than 10 nmol/L. In an MV4-11 mouse xenograft model, once daily oral dosing of ponatinib led to a dose-dependent inhibition of signaling and tumor regression. Ponatinib inhibited viability of primary leukemic blasts from a FLT3-ITD positive AML patient (IC50 4 nmol/L) but not those isolated from 3 patients with AML expressing native FLT3. Overall, these results support the investigation of ponatinib in patients with FLT3-ITD–driven AML and other hematologic malignancies driven by KIT, FGFR1, or PDGFRα. PMID:21482694

  13. Small-molecule p21-activated kinase inhibitor PF-3758309 is a potent inhibitor of oncogenic signaling and tumor growth

    PubMed Central

    Murray, Brion W.; Guo, Chuangxing; Piraino, Joseph; Westwick, John K.; Zhang, Cathy; Lamerdin, Jane; Dagostino, Eleanor; Knighton, Daniel; Loi, Cho-Ming; Zager, Michael; Kraynov, Eugenia; Popoff, Ian; Christensen, James G.; Martinez, Ricardo; Kephart, Susan E.; Marakovits, Joseph; Karlicek, Shannon; Bergqvist, Simon; Smeal, Tod

    2010-01-01

    Despite abundant evidence that aberrant Rho-family GTPase activation contributes to most steps of cancer initiation and progression, there is a dearth of inhibitors of their effectors (e.g., p21-activated kinases). Through high-throughput screening and structure-based design, we identify PF-3758309, a potent (Kd = 2.7 nM), ATP-competitive, pyrrolopyrazole inhibitor of PAK4. In cells, PF-3758309 inhibits phosphorylation of the PAK4 substrate GEF-H1 (IC50 = 1.3 nM) and anchorage-independent growth of a panel of tumor cell lines (IC50 = 4.7 ± 3 nM). The molecular underpinnings of PF-3758309 biological effects were characterized using an integration of traditional and emerging technologies. Crystallographic characterization of the PF-3758309/PAK4 complex defined determinants of potency and kinase selectivity. Global high-content cellular analysis confirms that PF-3758309 modulates known PAK4-dependent signaling nodes and identifies unexpected links to additional pathways (e.g., p53). In tumor models, PF-3758309 inhibits PAK4-dependent pathways in proteomic studies and regulates functional activities related to cell proliferation and survival. PF-3758309 blocks the growth of multiple human tumor xenografts, with a plasma EC50 value of 0.4 nM in the most sensitive model. This study defines PAK4-related pathways, provides additional support for PAK4 as a therapeutic target with a unique combination of functions (apoptotic, cytoskeletal, cell-cycle), and identifies a potent, orally available small-molecule PAK inhibitor with significant promise for the treatment of human cancers. PMID:20439741

  14. Potent activity of carfilzomib, a novel, irreversible inhibitor of the ubiquitin-proteasome pathway, against preclinical models of multiple myeloma

    PubMed Central

    Kuhn, Deborah J.; Chen, Qing; Voorhees, Peter M.; Strader, John S.; Shenk, Kevin D.; Sun, Congcong M.; Demo, Susan D.; Bennett, Mark K.; van Leeuwen, Fijs W. B.; Chanan-Khan, Asher A.

    2007-01-01

    The proteasome has emerged as an important target for cancer therapy with the approval of bortezomib, a first-in-class, reversible proteasome inhibitor, for relapsed/refractory multiple myeloma (MM). However, many patients have disease that does not respond to bortezomib, whereas others develop resistance, suggesting the need for other inhibitors with enhanced activity. We therefore evaluated a novel, irreversible, epoxomicin-related proteasome inhibitor, carfilzomib. In models of MM, this agent potently bound and specifically inhibited the chymotrypsin-like proteasome and immunoproteasome activities, resulting in accumulation of ubiquitinated substrates. Carfilzomib induced a dose- and time-dependent inhibition of proliferation, ultimately leading to apoptosis. Programmed cell death was associated with activation of c-Jun-N-terminal kinase, mitochondrial membrane depolarization, release of cytochrome c, and activation of both intrinsic and extrinsic caspase pathways. This agent also inhibited proliferation and activated apoptosis in patient-derived MM cells and neoplastic cells from patients with other hematologic malignancies. Importantly, carfilzomib showed increased efficacy compared with bortezomib and was active against bortezomib-resistant MM cell lines and samples from patients with clinical bortezomib resistance. Carfilzomib also overcame resistance to other conventional agents and acted synergistically with dexamethasone to enhance cell death. Taken together, these data provide a rationale for the clinical evaluation of carfilzomib in MM. PMID:17591945

  15. Novel 1H-imidazol-2-amine derivatives as potent and orally active vascular adhesion protein-1 (VAP-1) inhibitors for diabetic macular edema treatment.

    PubMed

    Inoue, Takayuki; Morita, Masataka; Tojo, Takashi; Nagashima, Akira; Moritomo, Ayako; Miyake, Hiroshi

    2013-07-01

    Novel thiazole derivatives were synthesized and evaluated as vascular adhesion protein-1 (VAP-1) inhibitors. Although we previously identified a compound (2) with potent VAP-1 inhibitory activity in rats, the human activity was relatively weak. Here, to improve the human VAP-1 inhibitory activity of compound 2, we first evaluated the structure-activity relationships of guanidine bioisosteres as simple small molecules and identified a 1H-benzimidazol-2-amine (5) with potent activity compared to phenylguanidine (1). Based on the structure of compound 5, we synthesized a highly potent VAP-1 inhibitor (37b; human IC50=0.019 μM, rat IC50=0.0051 μM). Orally administered compound 37b also markedly inhibited ocular permeability in streptozotocin-induced diabetic rats after oral administration, suggesting it is a promising compound for the treatment of diabetic macular edema.

  16. The novel trisubstituted pyran derivative D-142 has triple monoamine reuptake inhibitory activity and exerts potent antidepressant-like activity in rodents

    PubMed Central

    Dutta, Aloke K.; Gopishetty, Bhaskar; Gogoi, Sanjib; Ali, Solav; Zhen, Juan; Reith, Maarten

    2011-01-01

    Major depression disorder is a significant health problem with 10-20% of all adults suffering from this disease. The underlying causes of depression are still unclear and 15% of depressed patients are resistant to all known therapies. Monoamine therapies have so far been the most successful approach for treating depression. Triple monoamine reuptake inhibitors have recently been implicated in generation of potent antidepressant activity while possibly exhibiting a low side-effect profile in addition to treating anhedonia. The additional, previously under-appreciated involvement of dopaminergic systems in depression prompted our efforts to develop novel asymmetric trisubstituted and disubstituted pyran derivatives as triple reuptake inhibitors. One of the lead compounds, D-142, exhibited uptake inhibition (Ki) values of 29.3 nM, 14.7 nM and 37.4 nM for norepinephrine, serotonin and dopamine transporters, respectively. Its affinity for serotonin transporter was comparable to fluoxetine , a well known SSRI. In the rat forced swimming test, compound D-142 exhibited potent antidepressant activity in the dose range tested (2.5, 5 and 10 mg/kg) and was far more efficacious than the reference compound imipramine. In the mouse tail suspension test, compound D-142 reduced immobility in a dose (2.5, 5 and 10 mg/kg) dependent manner, indicating a potent antidepressant effect. In locomotor activity tests, compound D-142 did not exhibit any stimulation in the same dose ranges. In the extended CNS receptors screening assay this molecule exhibited little or no non-specific interaction in the CNS, indicating high specificity for monoamine transporters. These results advance D-142 as a potential potent antidepressant. PMID:21963455

  17. Triggering through NOD-2 Differentiates Bone Marrow Precursors to Dendritic Cells with Potent Bactericidal activity

    PubMed Central

    Khan, Nargis; Aqdas, Mohammad; Vidyarthi, Aurobind; Negi, Shikha; Pahari, Susanta; Agnihotri, Tapan; Agrewala, Javed N.

    2016-01-01

    Dendritic cells (DCs) play a crucial role in bridging innate and adaptive immunity by activating naïve T cells. The role of pattern recognition receptors like Toll-Like Receptors and Nod-Like Receptors expressed on DCs is well-defined in the recognition of the pathogens. However, nothing is precisely studied regarding the impact of NOD-2 signaling during the differentiation of DCs. Consequently, we explored the role of NOD-2 signaling in the differentiation of DCs and therefore their capability to activate innate and adaptive immunity. Intriguingly, we observed that NOD-2 stimulated DCs (nDCs) acquired highly activated and matured phenotype and exhibited substantially greater bactericidal activity by robust production of nitric oxide. The mechanism involved in improving the functionality of nDCs was dependent on IFN-αβ signaling, leading to the activation of STAT pathways. Furthermore, we also observed that STAT-1 and STAT-4 dependent maturation and activation of DCs was under the feedback mechanism of SOCS-1 and SOCS-3 proteins. nDCs acquired enhanced potential to activate chiefly Th1 and Th17 immunity. Taken together, these results suggest that nDCs can be exploited as an immunotherapeutic agent in bolstering host immunity and imparting protection against the pathogens. PMID:27265209

  18. Synthesis of novel substituted 2-phenylpyrazolopyridines with potent activity against herpesviruses.

    PubMed

    Gudmundsson, Kristjan S; Johns, Brian A; Wang, Zhicheng; Turner, Elizabeth M; Allen, Scott H; Freeman, George A; Boyd, F Leslie; Sexton, Connie J; Selleseth, Dean W; Moniri, Kelly R; Creech, Katrina L

    2005-09-15

    Herpesviruses are a significant source of human disease; amongst these herpes simplex virus 1 (HSV-1) and HSV-2 are very prevalent and cause recurrent infections. We recently identified a pyrazolo[1,5-a]pyridine scaffold that showed promising activity against HSV-1 and HSV-2 in Vero cell antiviral assays. Here, we describe the synthesis and anti-herpetic activity of several 3-pyrimidinyl-2-phenylpyrazolo[1,5-a]pyridines with differing 2-phenyl substitution patterns. Approaches to rapidly access a number of analogs with different 2-phenyl substitution patterns are outlined. Several of the compounds described have comparable activity to acyclovir against HSV-1 and HSV-2.

  19. Structurally well-defined macrophage activating factor derived from vitamin D3-binding protein has a potent adjuvant activity for immunization.

    PubMed

    Yamamoto, N; Naraparaju, V R

    1998-06-01

    Freund's adjuvant produced severe inflammation that augments development of antibodies. Thus, mixed administration of antigens with adjuvant was not required as long as inflammation was induced in the hosts. Since macrophage activation for phagocytosis and antigen processing is the first step of antibody development, inflammation-primed macrophage activation plays a major role in immune development. Therefore, macrophage activating factor should act as an adjuvant for immunization. The inflammation-primed macrophage activation process is the major macrophage activating cascade that requires participation of serum vitamin D3-binding protein (DBP; human DBP is known as Gc protein) and glycosidases of B and T lymphocytes. Stepwise incubation of Gc protein with immobilized beta-galactosidase and sialidase efficiently generated the most potent macrophage activating factor (designated GcMAF) we have ever encountered. Administration of GcMAF (20 or 100 pg/mouse) resulted in stimulation of the progenitor cells for extensive mitogenesis and activation of macrophages. Administration of GcMAF (100 pg/mouse) along with immunization of mice with sheep red blood cells (SRBC) produced a large number of anti-SRBC antibody secreting splenic cells in 2-4 days. Thus, GcMAF has a potent adjuvant activity for immunization. Although malignant tumours are poorly immunogenic, 4 days after GcMAF-primed immunization of mice with heat-killed Ehrlich ascites tumour cells, the ascites tumour was no longer transplantable in these mice.

  20. Water extracts of cinnamon and clove exhibits potent inhibition of protein glycation and anti-atherosclerotic activity in vitro and in vivo hypolipidemic activity in zebrafish.

    PubMed

    Jin, Seori; Cho, Kyung-Hyun

    2011-07-01

    Advanced glycation end products contribute to the pathogenesis of diabetic complications and atherosclerosis. Aqueous extracts of ground pepper, cinnamon, rosemary, ginger, and clove were analyzed and tested for anti-atherosclerotic activity in vitro and in vivo using hypercholesterolemic zebrafish. Cinnamon and clove extracts (at final 10 μg/mL) had the strongest anti-glycation and antioxidant activity in this study. Cinnamon and clove had the strongest inhibition of activity against copper-mediated low-density lipoprotein (LDL) oxidation and LDL phagocytosis by macrophages. Cinnamon or clove extracts had potent cholesteryl ester transfer protein (CETP) inhibitory activity in a concentration-dependent manner. They exhibited hypolipidemic activity in a hypercholesterolemic zebrafish model; the clove extract-treated group had a 68% and 80% decrease in serum cholesterol and TG levels, respectively. The clove extract-fed group had the smallest increase in body weight and height and the strongest antioxidant activity following a 5-week high cholesterol diet. Hydrophilic ingredients of cinnamon and clove showed potent activities to suppress the incidence of atherosclerosis and diabetes via strong antioxidant potential, prevention of apoA-I glycation and LDL-phagocytosis, inhibition of CETP, and hypolipidemic activity. These results suggest the potential to develop a new functional dietary agent to treat chronic metabolic diseases, such as hyperlipidemia and diabetes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Isolation and chemical analysis of a fatty acid fraction of Kalanchoe pinnata with a potent lymphocyte suppressive activity.

    PubMed

    Almeida, A P; Da Silva, S A; Souza, M L; Lima, L M; Rossi-Bergmann, B; de Moraes, V L; Costa, S S

    2000-03-01

    Previously we demonstrated that Kalanchoe pinnata (KP) leaf extracts inhibited in vitro lymphocyte proliferation and showed in vivo immunosuppressive activity. Here we attempt to identify the immunosuppressive substances present in KP guided by the lymphoproliferative assays. From the ethanolic extract was purified a fraction (KP12SA) twenty-fold more potent to block murine lymphocyte proliferation than the crude extract. Chemical analysis by 1H- and 13C-NMR, IR and GC-MS of KP12SA (methylated sample) showed 89.3% of palmitic acid (C16), 10.7% of stearic acid (C18) and traces of arachidic (C20) and behenic acids (C22). This study provides evidence that fatty acids present in Kalanchoe pinnata may be responsible, at least in part, for its immunosuppressive effect in vivo.

  2. Discovery and Structure-Activity Relationship Study of 4-Phenoxythiazol-5-carboxamides as Highly Potent TGR5 Agonists.

    PubMed

    Chen, Zhixiang; Ning, Mengmeng; Zou, Qingan; Cao, Hua; Ye, Yangliang; Leng, Ying; Shen, Jianhua

    2016-01-01

    A novel therapy that stimulates endogenous glucagon-like peptide-1 (GLP-1) secretion by Takeda G-protein-coupled receptor 5 (TGR5) agonists might be a superior alternative for the treatment of type 2 diabetes mellitus. A series of 4-phenoxythiazol-5-carboxamides were developed as highly potent TGR5 agonists using a bioisosteric replacement strategy based on the scaffold of 4-phenoxynicotinamides. The structure-activity relationship on the bottom phenyl ring and the thiazole ring was extensively studied, and the 2-methyl-thiazole derivatives 30c and e displayed the best in vitro potency toward human TGR5, with EC50 values of approximately 1 nM. While endowed with excellent in vitro potency, the 2-methyl-thiazoles were flawed with high microsomal clearance.

  3. Pyrrolo[3',2':6,7]cyclohepta[1,2-b]pyridines with potent photo-antiproliferative activity.

    PubMed

    Spanò, Virginia; Giallombardo, Daniele; Cilibrasi, Vincenzo; Parrino, Barbara; Carbone, Anna; Montalbano, Alessandra; Frasson, Ilaria; Salvador, Alessia; Richter, Sara N; Doria, Filippo; Freccero, Mauro; Cascioferro, Stella; Diana, Patrizia; Cirrincione, Girolamo; Barraja, Paola

    2017-03-10

    Pyrrolo[3',2':6,7]cyclohepta[1,2-b]pyridines were synthesized as a new class of tricyclic system in which the pyridine ring is annelated to a cycloheptapyrrole scaffold, with the aim of obtaining new photosensitizing agents with improved antiproliferative activity and lower undesired toxic effects. A versatile synthetic pathway was approached, which allowed the isolation of derivatives of the title ring system with a good substitution pattern on the pyrrole moiety. Photobiological studies revealed that the majority of the new compounds showed a potent cytotoxic effect upon photoactivation with light of the proper wavelength, especially when decorated with a 2-ethoxycabonyl group and a N-benzyl substituted moiety, with EC50 values reaching the submicromolar level. The mechanism of action was evaluated.

  4. Honaucins A–C, Potent Inhibitors of Eukaryotic Inflammation and Bacterial Quorum Sensing: Synthetic Derivatives and Structure-Activity Relationships

    PubMed Central

    Choi, Hyukjae; Mascuch, Samantha J.; Villa, Francisco A.; Byrum, Tara; Teasdale, Margaret E.; Smith, Jennifer E.; Preskitt, Linda B.; Rowley, David C.; Gerwick, Lena; Gerwick, William H.

    2012-01-01

    SUMMARY Honaucins A–C were isolated from the cyanobacterium Leptolyngbya crossbyana which was found overgrowing corals on the Hawaiian coast. Honaucin A consists of (S)-3-hydroxy-γ-butyrolactone and 4-chlorocrotonic acid which are connected via an ester linkage. Honaucin A and its two natural analogs exhibit potent inhibition of bioluminescence, a quorum sensing-dependent phenotype, in Vibrio harveyi BB120 as well as of lipopolysaccharide-stimulated nitric oxide production in the murine macrophage cell line RAW264.7. The decrease in nitric oxide production was accompanied by a decrease in the transcripts of several pro-inflammatory cytokines, most dramatically interleukin-1β. Synthesis of honaucin A as well as a number of analogs and subsequent evaluation in anti-inflammation and quorum sensing inhibition bioassays revealed the essential structural features for activity in this chemical class, and provided analogs with greater potency in both assays. PMID:22633410

  5. Cytochrome P450-mediated activation of the fragrance compound geraniol forms potent contact allergens

    SciTech Connect

    Hagvall, Lina; Baron, Jens Malte; Boerje, Anna; Weidolf, Lars; Merk, Hans; Karlberg, Ann-Therese

    2008-12-01

    Contact sensitization is caused by low molecular weight compounds which penetrate the skin and bind to protein. In many cases, these compounds are activated to reactive species, either by autoxidation on exposure to air or by metabolic activation in the skin. Geraniol, a widely used fragrance chemical, is considered to be a weak allergen, although its chemical structure does not indicate it to be a contact sensitizer. We have shown that geraniol autoxidizes and forms allergenic oxidation products. In the literature, it is suggested but not shown that geraniol could be metabolically activated to geranial. Previously, a skin-like CYP cocktail consisting of cutaneous CYP isoenzymes, was developed as a model system to study cutaneous metabolism. In the present study, we used this system to investigate CYP-mediated activation of geraniol. In incubations with the skin-like CYP cocktail, geranial, neral, 2,3-epoxygeraniol, 6,7-epoxygeraniol and 6,7-epoxygeranial were identified. Geranial was the main metabolite formed followed by 6,7-epoxygeraniol. The allergenic activities of the identified metabolites were determined in the murine local lymph node assay (LLNA). Geranial, neral and 6,7-epoxygeraniol were shown to be moderate sensitizers, and 6,7-epoxygeranial a strong sensitizer. Of the isoenzymes studied, CYP2B6, CYP1A1 and CYP3A5 showed high activities. It is likely that CYP1A1 and CYP3A5 are mainly responsible for the metabolic activation of geraniol in the skin, as they are expressed constitutively at significantly higher levels than CYP2B6. Thus, geraniol is activated through both autoxidation and metabolism. The allergens geranial and neral are formed via both oxidation mechanisms, thereby playing a large role in the sensitization to geraniol.

  6. Hapivirins and Diprovirins: Novel θ-Defensin Analogs With Potent Activity Against Influenza A Virusa

    PubMed Central

    Doss, Mona; Ruchala, Piotr; Tecle, Tesfaldet; Gantz, Donald; Verma, Anamika; Hartshorn, Alex; Crouch, Erika C.; Luong, Hai; Micewicz, Ewa D.; Lehrer, Robert I.; Hartshorn, Kevan L.

    2012-01-01

    θ-defensins are cyclic octadecapeptides found in non-human primates whose broad antiviral-spectrum includes HIV-1, HSV-1, SARS, and influenza A virus (IAV). We previously reported that synthetic θ-defensins called retrocyclins can neutralize and aggregate various strains of IAV and increase IAV uptake by neutrophils. This report describes two families of peptides, hapivirins (HpVs) and diprovirins (DpVs), whose design was inspired by retrocyclins. The goal was to develop smaller partially cyclic peptides that retain the antiviral activity of retrocyclins, while being easier to synthesize. The novel peptides also allowed for systemic substitution of key residues to evaluate the role of charge or hydrophobicity on antiviral activity. Seventy-two HpV or DpV peptides are described in this report, including several whose anti-IAV activity equals or exceeds that of normal α– or θ-defensins. Some of these also had strong antibacterial and antifungal activity. These new peptides were active against H3N2 and H1N1 strains of IAV. Structural features imparting strong antiviral activity were identified through iterative cycles of synthesis and testing. Our findings show the importance of hydrophobic residues for antiviral activity and show that pegylation, which often increases a peptide’s serum half-life in vivo, can increase the antiviral activity of DpVs. The new peptides acted at an early phase of viral infection and when combined with pulmonary surfactant protein D, their antiviral effects were additive. The peptides strongly increased neutrophil and macrophage uptake of IAV, while inhibiting monocyte cytokine generation. Development of modified θ– defensin analogues provides an approach for creating novel antiviral agents for IAV infections. PMID:22345650

  7. Identification of potent anticancer activity in Ximenia americana aqueous extracts used by African traditional medicine

    SciTech Connect

    Voss, Cristina; Eyol, Erguel; Berger, Martin R. . E-mail: m.berger@dkfz.de

    2006-03-15

    The antineoplastic activity of a plant powder used in African traditional medicine for treating cancer was investigated by analyzing the activity of various extracts in vitro. The most active, aqueous extract was subsequently subjected to a detailed investigation in a panel of 17 tumor cell lines, showing an average IC{sub 5} of 49 mg raw powder/ml medium. The sensitivity of the cell lines varied by two orders of magnitude, from 1.7 mg/ml in MCF7 breast cancer cells to 170 mg/ml in AR230 chronic-myeloid leukemia cells. Immortalized, non-tumorigenic cell lines showed a marginal sensitivity. In addition, kinetic and recovery experiments performed in MCF7 and U87-MG cells and a comparison with the antineoplastic activity of miltefosine, gemcitabine, and cisplatinum in MCF7, U87-MG, HEp2, and SAOS2 cells revealed no obvious similarity between the sensitivity profiles of the extract and the three standard agents, suggesting a different mechanism of cytotoxicity. The in vivo antitumor activity was determined in the CC531 colorectal cancer rat model. Significant anticancer activity was found following administration of equitoxic doses of 100 (perorally) and 5 (intraperitoneally) mg raw powder/kg, indicating a 95% reduced activity following intestinal absorption. By sequencing the mitochondrial gene for the large subunit of the ribulose bis-phosphate carboxylase (rbcL) in DNA from the plant material, the source plant was identified as Ximenia americana. A physicochemical characterization showed that the active antineoplastic component(s) of the plant material are proteins with galactose affinity. Moreover, by mass spectrometry, one of these proteins was shown to contain a stretch of 11 amino acids identical to a tryptic peptide from the ribosome-inactivating protein ricin.

  8. By Homing to the Kidney, Activated Macrophages Potently Exacerbate Renal Injury

    PubMed Central

    Wang, Ying; Wang, Yiping; Cai, Qi; Zheng, Guoping; Lee, Vincent W.S.; Zheng, Dong; Li, Xiaomei; Kui Tan, Thian; Harris, David C.H.

    2008-01-01

    Macrophages are important mediators of injury in most types of human kidney diseases; however, the pathogenic importance of both macrophage number and activation status is unknown. To examine this question, severe-combined immunodeficient mice with adriamycin nephrosis, an experimental model of human focal segmental glomerulosclerosis, were treated intravenously with either resting (1 × 106 to 5 × 106) or activated (1 × 103 to 1 × 106) macrophages on day 6 postadriamycin administration, and the effects on kidney injury were examined. On day 28, renal injury was worse in the group that received activated macrophages at doses as low as 1 × 104 macrophages per mouse compared with control adriamycin nephrotic mice. However, treatment with resting macrophages at doses as high as 5 × 106 macrophages per mouse had no significant effect on either renal histology or function. The transferred activated macrophages homed to inflamed kidneys during the middle-to-late stages of the disease, but such homing was not observed for resting macrophages. This study of in vivo cell adoptive transfer supports the importance of macrophage activation status over macrophage number in causing renal injury. These data suggest that therapeutic strategies for treating progressive kidney diseases should target activated macrophages. PMID:18467704

  9. SB 9200, a novel agonist of innate immunity, shows potent antiviral activity against resistant HCV variants.

    PubMed

    Jones, Meleri; Cunningham, Morven E; Wing, Peter; DeSilva, Sampath; Challa, Rupa; Sheri, Anjaneyulu; Padmanabhan, Seetharamaiyer; Iyer, Radhakrishnan P; Korba, Brent E; Afdhal, Nezam; Foster, Graham R

    2017-09-01

    SB 9200 is a novel, first-in-class oral modulator of innate immunity that is believed to act via the activation of the RIG-I and NOD2 pathways. SB 9200 has broad-spectrum antiviral activity against RNA viruses including hepatitis C virus (HCV), norovirus, respiratory syncytial virus, and influenza and has demonstrated activity against hepatitis B virus (HBV) in vitro and in vivo. In phase I clinical trials in chronically infected HCV patients, SB 9200 has been shown to reduce HCV RNA by up to 1.9 log10 . Here, we demonstrate the antiviral activity of SB 9200 against a HCV replicon system and patient derived virus. Using the HCV capture-fusion assay, we show that SB 9200 is active against diverse HCV genotypes and is also effective against HCV derived from patients who relapse following direct-acting antiviral treatment, including viruses containing known NS5A resistance-associated sequences. These data confirm the broad antiviral activity of SB 9200 and indicate that it may have clinical utility in HCV patients who have failed to respond to current antiviral regimens. © 2017 Wiley Periodicals, Inc.

  10. Potent in vitro antiviral activity of Cistus incanus extract against HIV and Filoviruses targets viral envelope proteins

    PubMed Central

    Rebensburg, Stephanie; Helfer, Markus; Schneider, Martha; Koppensteiner, Herwig; Eberle, Josef; Schindler, Michael; Gürtler, Lutz; Brack-Werner, Ruth

    2016-01-01

    Novel therapeutic options are urgently needed to improve global treatment of virus infections. Herbal products with confirmed clinical safety features are attractive starting material for the identification of new antiviral activities. Here we demonstrate that Cistus incanus (Ci) herbal products inhibit human immunodeficiency virus (HIV) infections in vitro. Ci extract inhibited clinical HIV-1 and HIV-2 isolates, and, importantly, a virus isolate with multiple drug resistances, confirming broad anti-HIV activity. Antiviral activity was highly selective for virus particles, preventing primary attachment of the virus to the cell surface and viral envelope proteins from binding to heparin. Bioassay-guided fractionation indicated that Ci extract contains numerous antiviral compounds and therefore has favorably low propensity to induce virus resistance. Indeed, no resistant viruses emerged during 24 weeks of continuous propagation of the virus in the presence of Ci extracts. Finally, Ci extracts also inhibited infection by virus particles pseudotyped with Ebola and Marburg virus envelope proteins, indicating that antiviral activity of Ci extract extends to emerging viral pathogens. These results demonstrate that Ci extracts show potent and broad in vitro antiviral activity against viruses that cause life-threatening diseases in humans and are promising sources of agents that target virus particles. PMID:26833261

  11. AZD-4547 exerts potent cytostatic and cytotoxic activities against fibroblast growth factor receptor (FGFR)-expressing colorectal cancer cells.

    PubMed

    Yao, Ting-Jing; Zhu, Jin-Hai; Peng, De-Feng; Cui, Zhen; Zhang, Chao; Lu, Pei-hua

    2015-07-01

    Colorectal cancer (CRC) causes significant mortalities worldwide. Fibroblast growth factor (FGF) receptor (FGFR) signaling is frequently dysregulated and/or constitutively activated in CRCs, contributing to cancer carcinogenesis and progression. Here, we studied the activity of AZD-4547, a novel and potent FGFR kinase inhibitor, on CRC cells. AZD-4547 inhibited CRC cell growth in vitro, and its activity correlated with the FGFR-1/2 expression level. AZD-4547 was cytotoxic and pro-apoptotic in FGFR-1/2-expressed CRC cell lines (NCI-H716 and HCT-116), but not in FGFR-1/2 null HT-29 cells. Further, AZD-4547 inhibited cell cycle progression and attenuated the activation of FGFR1-FGFR substrate 2 (FRS-2), ERK/mitogen-activated protein kinase (MAPK), and AKT/mammalian target of rapamycin (AKT/mTOR) signalings in NCI-H716 and HCT-116 cells. In vivo, AZD-4547 oral administration at effective doses inhibited NCI-H716 (high FGFR-1/2 expression) xenograft growth in nude mice. Phosphorylation of FGFR-1, AKT, and ERK1/2 in xenograft specimens was also inhibited by AZD-4547 administration. Thus, our preclinical studies strongly support possible clinical investigations of AZD-4547 for the treatment of CRCs harboring deregulated FGFR signalings.

  12. Potent in vitro antiviral activity of Cistus incanus extract against HIV and Filoviruses targets viral envelope proteins.

    PubMed

    Rebensburg, Stephanie; Helfer, Markus; Schneider, Martha; Koppensteiner, Herwig; Eberle, Josef; Schindler, Michael; Gürtler, Lutz; Brack-Werner, Ruth

    2016-02-02

    Novel therapeutic options are urgently needed to improve global treatment of virus infections. Herbal products with confirmed clinical safety features are attractive starting material for the identification of new antiviral activities. Here we demonstrate that Cistus incanus (Ci) herbal products inhibit human immunodeficiency virus (HIV) infections in vitro. Ci extract inhibited clinical HIV-1 and HIV-2 isolates, and, importantly, a virus isolate with multiple drug resistances, confirming broad anti-HIV activity. Antiviral activity was highly selective for virus particles, preventing primary attachment of the virus to the cell surface and viral envelope proteins from binding to heparin. Bioassay-guided fractionation indicated that Ci extract contains numerous antiviral compounds and therefore has favorably low propensity to induce virus resistance. Indeed, no resistant viruses emerged during 24 weeks of continuous propagation of the virus in the presence of Ci extracts. Finally, Ci extracts also inhibited infection by virus particles pseudotyped with Ebola and Marburg virus envelope proteins, indicating that antiviral activity of Ci extract extends to emerging viral pathogens. These results demonstrate that Ci extracts show potent and broad in vitro antiviral activity against viruses that cause life-threatening diseases in humans and are promising sources of agents that target virus particles.

  13. Rice endosperm is cost-effective for the production of recombinant griffithsin with potent activity against HIV.

    PubMed

    Vamvaka, Evangelia; Arcalis, Elsa; Ramessar, Koreen; Evans, Abbey; O'Keefe, Barry R; Shattock, Robin J; Medina, Vicente; Stöger, Eva; Christou, Paul; Capell, Teresa

    2016-06-01

    Protein microbicides containing neutralizing antibodies and antiviral lectins may help to reduce the rate of infection with human immunodeficiency virus (HIV) if it is possible to manufacture the components in large quantities at a cost affordable in HIV-endemic regions such as sub-Saharan Africa. We expressed the antiviral lectin griffithsin (GRFT), which shows potent neutralizing activity against HIV, in the endosperm of transgenic rice plants (Oryza sativa), to determine whether rice can be used to produce inexpensive GRFT as a microbicide ingredient. The yield of (OS) GRFT in the best-performing plants was 223 μg/g dry seed weight. We also established a one-step purification protocol, achieving a recovery of 74% and a purity of 80%, which potentially could be developed into a larger-scale process to facilitate inexpensive downstream processing. (OS) GRFT bound to HIV glycans with similar efficiency to GRFT produced in Escherichia coli. Whole-cell assays using purified (OS) GRFT and infectivity assays using crude extracts of transgenic rice endosperm confirmed that both crude and pure (OS) GRFT showed potent activity against HIV and the crude extracts were not toxic towards human cell lines, suggesting they could be administered as a microbicide with only minimal processing. A freedom-to-operate analysis confirmed that GRFT produced in rice is suitable for commercial development, and an economic evaluation suggested that 1.8 kg/ha of pure GRFT could be produced from rice seeds. Our data therefore indicate that rice could be developed as an inexpensive production platform for GRFT as a microbicide component.

  14. Exploring pharmacological activities and signaling of morphinans substituted in position 6 as potent agonists interacting with the μ opioid receptor

    PubMed Central

    2014-01-01

    Background Opioid analgesics are the most effective drugs for the treatment of moderate to severe pain. However, they also produce several adverse effects that can complicate pain management. The μ opioid (MOP) receptor, a G protein-coupled receptor, is recognized as the opioid receptor type which primarily mediates the pharmacological actions of clinically used opioid agonists. The morphinan class of analgesics including morphine and oxycodone are of main importance as therapeutically valuable drugs. Though the natural alkaloid morphine contains a C-6-hydroxyl group and the semisynthetic derivative oxycodone has a 6-carbonyl function, chemical approaches have uncovered that functionalizing position 6 gives rise to a range of diverse activities. Hence, position 6 of N-methylmorphinans is one of the most manipulated sites, and is established to play a key role in ligand binding at the MOP receptor, efficacy, signaling, and analgesic potency. We have earlier reported on a chemically innovative modification in oxycodone resulting in novel morphinans with 6-acrylonitrile incorporated substructures. Results This study describes in vitro and in vivo pharmacological activities and signaling of new morphinans substituted in position 6 with acrylonitrile and amido functions as potent agonists and antinociceptive agents interacting with MOP receptors. We show that the presence of a 6-cyano group in N-methylmorphinans has a strong influence on the binding to the opioid receptors and post-receptor signaling. One 6-cyano-N-methylmorphinan of the series was identified as the highest affinity and most selective MOP agonist, and very potent in stimulating G protein coupling and intracellular calcium release through the MOP receptor. In vivo, this MOP agonist showed to be greatly effective against thermal and chemical nociception in mice with marked increased antinociceptive potency than the lead molecule oxycodone. Conclusion Development of such novel chemotypes by targeting

  15. Novel fluorinated pyrrolomycins as potent anti-staphylococcal biofilm agents: Design, synthesis, pharmacokinetics and antibacterial activities.

    PubMed

    Yang, Zunhua; Liu, Yan; Ahn, Jongsam; Qiao, Zhen; Endres, Jennifer L; Gautam, Nagsen; Huang, Yunlong; Li, Jerry; Zheng, Jialin; Alnouti, Yazen; Bayles, Kenneth W; Li, Rongshi

    2016-11-29

    Staphylococcus aureus (SA) is a major cause of hospital- and community-associated bacterial infections in the U.S. and around the world. These infections have become increasingly difficult to treat due to the propensity to develop antibiotic resistance and form biofilm. To date, no antibiofilm agents are available for clinical use. To add to the repertoire of antibiotics for clinical use and to provide novel agents for combating both SA and biofilm infections, we previously reported marinopyrroles as potent anti-SA agents. In this study, we used fragment-based and bioisostere approaches to design and synthesize a series of novel fluorinated pyrrolomycins for the first time, performed analyses of their physicochemical and drug-like properties, and investigated structure activity relationships and pharmacokinetics. These promising fluorinated pyrrolomycins demonstrate potent antibacterial activity against SA with favorable drug-like properties and pharmacokinetic profiles. Importantly, these compounds kill staphylococcal biofilm-associated cells with a lack of mammalian cell cytotoxicity and no occurrence of bacterial resistance. Our novel fluorinated pyrrolomycin 4 has a clogP value of 4.1, an MIC of 73 ng/mL, MBC of 4 μg/mL, kill staphylococcal-associated biofilm at 8 μg/mL, bioavailability of 35%, and the elimination half-life of 6.04 h and 6.75 h by intravenous and oral administration, respectively. This is the first report of comprehensive drug discovery studies on pyrrolomycin-based antibiotics. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  16. A novel ribonuclease with potent HIV-1 reverse transcriptase inhibitory activity from cultured mushroom Schizophyllum commune.

    PubMed

    Zhao, Yong-Chang; Zhang, Guo-Qing; Ng, Tzi-Bun; Wang, He-Xiang

    2011-10-01

    A 20-kDa ribonuclease (RNase) was purified from fresh fruiting bodies of cultured Schizophyllum commune mushrooms. The RNase was not adsorbed on Affi-gel blue gel but adsorbed on DEAE-cellulose and CM-cellulose. It exhibited maximal RNase activity at pH 6.0 and 70°C. It demonstrated the highest ribonucleolytic activity toward poly (U) (379.5 μ/mg), the second highest activity toward poly (C) (244.7 μ/mg), less activity toward poly (A) (167.4 μ/mg), and much weaker activity toward poly (G) (114.5 μ/mg). The RNase inhibited HIV-1 reverse transcriptase with an IC(50) of 65 μM. No effect on [(3)H-methyl]-thymidine uptake by lymphoma MBL2 cells and leukemia L1210 cells was observed at 100 μM concentration of the RNase. A comparison of RNases from S. commune and Volvariella volvacea revealed that they demonstrated some similarities in N-terminal amino acid sequence, optimum pH and polyhomoribonucleotide specificity. However, some differences in chromatographic behavior and molecular mass were observed.

  17. A Novel Time-Dependent CENP-E Inhibitor with Potent Antitumor Activity

    PubMed Central

    Ohashi, Akihiro; Ohori, Momoko; Iwai, Kenichi; Nambu, Tadahiro; Miyamoto, Maki; Kawamoto, Tomohiro; Okaniwa, Masanori

    2015-01-01

    Centromere-associated protein E (CENP-E) regulates both chromosome congression and the spindle assembly checkpoint (SAC) during mitosis. The loss of CENP-E function causes chromosome misalignment, leading to SAC activation and apoptosis during prolonged mitotic arrest. Here, we describe the biological and antiproliferative activities of a novel small-molecule inhibitor of CENP-E, Compound-A (Cmpd-A). Cmpd-A inhibits the ATPase activity of the CENP-E motor domain, acting as a time-dependent inhibitor with an ATP-competitive-like behavior. Cmpd-A causes chromosome misalignment on the metaphase plate, leading to prolonged mitotic arrest. Treatment with Cmpd-A induces antiproliferation in multiple cancer cell lines. Furthermore, Cmpd-A exhibits antitumor activity in a nude mouse xenograft model, and this antitumor activity is accompanied by the elevation of phosphohistone H3 levels in tumors. These findings demonstrate the potency of the CENP-E inhibitor Cmpd-A and its potential as an anticancer therapeutic agent. PMID:26649895

  18. Activity of Potent and Selective Host Defense Peptide Mimetics in Mouse Models of Oral Candidiasis

    PubMed Central

    Ryan, Lisa K.; Freeman, Katie B.; Masso-Silva, Jorge A.; Falkovsky, Klaudia; Aloyouny, Ashwag; Markowitz, Kenneth; Hise, Amy G.; Fatahzadeh, Mahnaz; Scott, Richard W.

    2014-01-01

    There is a strong need for new broadly active antifungal agents for the treatment of oral candidiasis that not only are active against many species of Candida, including drug-resistant strains, but also evade microbial countermeasures which may lead to resistance. Host defense peptides (HDPs) can provide a foundation for the development of such agents. Toward this end, we have developed fully synthetic, small-molecule, nonpeptide mimetics of the HDPs that improve safety and other pharmaceutical properties. Here we describe the identification of several HDP mimetics that are broadly active against C. albicans and other species of Candida, rapidly fungicidal, and active against yeast and hyphal cultures and that exhibit low cytotoxicity for mammalian cells. Importantly, specificity for Candida over commensal bacteria was also evident, thereby minimizing potential damage to the endogenous microbiome which otherwise could favor fungal overgrowth. Three compounds were tested as topical agents in two different mouse models of oral candidiasis and were found to be highly active. Following single-dose administrations, total Candida burdens in tongues of infected animals were reduced up to three logs. These studies highlight the potential of HDP mimetics as a new tool in the antifungal arsenal for the treatment of oral candidiasis. PMID:24752272

  19. Negatively charged silver nanoparticles with potent antibacterial activity and reduced toxicity for pharmaceutical preparations.

    PubMed

    Salvioni, Lucia; Galbiati, Elisabetta; Collico, Veronica; Alessio, Giulia; Avvakumova, Svetlana; Corsi, Fabio; Tortora, Paolo; Prosperi, Davide; Colombo, Miriam

    2017-01-01

    The discovery of new solutions with antibacterial activity as efficient and safe alternatives to common preservatives (such as parabens) and to combat emerging infections and drug-resistant bacterial pathogens is highly expected in cosmetics and pharmaceutics. Colloidal silver nanoparticles (NPs) are attracting interest as novel effective antimicrobial agents for the prevention of several infectious diseases. Water-soluble, negatively charged silver nanoparticles (AgNPs) were synthesized by reduction with citric and tannic acid and characterized by transmission electron microscopy, dynamic light scattering, zeta potential, differential centrifuge sedimentation, and ultraviolet-visible spectroscopy. AgNPs were tested with model Gram-negative and Gram-positive bacteria in comparison to two different kinds of commercially available AgNPs. In this work, AgNPs with higher antibacterial activity compared to the commercially available colloidal silver solutions were prepared and investigated. Bacteria were plated and the antibacterial activity was tested at the same concentration of silver ions in all samples. The AgNPs did not show any significant reduction in the antibacterial activity for an acceptable time period. In addition, AgNPs were transferred to organic phase and retained their antibacterial efficacy in both aqueous and nonaqueous media and exhibited no toxicity in eukaryotic cells. We developed AgNPs with a 20 nm diameter and negative zeta potential with powerful antibacterial activity and low toxicity compared to currently available colloidal silver, suitable for cosmetic preservatives and pharmaceutical preparations administrable to humans and/or animals as needed.

  20. Discovery of novel Ponatinib analogues for reducing KDR activity as potent FGFRs inhibitors.

    PubMed

    Liu, Yang; Peng, Xia; Guan, Xiaocong; Lu, Dong; Xi, Yong; Jin, Shiyu; Chen, Hui; Zeng, Limin; Ai, Jing; Geng, Meiyu; Hu, Youhong

    2017-01-27

    FGF receptors (FGFRs) are tyrosine kinases that are overexpressed in diverse tumors by genetic alterations such as gene amplifications, somatic mutations and translocations. Owing to this characteristic, FGFRs are attractive targets for cancer treatment. It has been demonstrated that most multi-targeted, ATP competitive tyrosine kinase inhibitors are active against FGFRs as well as other kinases. The design of new and more selective inhibitors of FGFRs, which might be reduced off-target and side effects, is a difficult yet significant challenge. The results of the current investigation, show that novel Ponatinib analogues are highly active as FGFR inhibitors and that they possess reduced kinase insert domain receptor (KDR) activities. Observations made in a structure and activity relationship (SAR) investigation led to the development of a promising, orally available lead compound 4, which displays a 50-100 fold in vitro selectivity for inhibition of FGFR1-3 over KDR. In addition, biological evaluation of compound 4 showed that it displays significant antitumor activities in FGFR1-amplificated H1581 and FGFR2-amplificated SNU-16 xenograft models.

  1. Optogenetic excitation of preBötzinger complex neurons potently drives inspiratory activity in vivo

    PubMed Central

    Alsahafi, Zaki; Dickson, Clayton T; Pagliardini, Silvia

    2015-01-01

    Understanding the sites and mechanisms underlying respiratory rhythmogenesis is of fundamental interest in the field of respiratory neurophysiology. Previous studies demonstrated the necessary and sufficient role of preBötzinger complex (preBötC) in generating inspiratory rhythms in vitro and in vivo. However, the influence of timed activation of the preBötC network in vivo is as yet unknown given the experimental approaches previously used. By unilaterally infecting preBötC neurons using an adeno-associated virus expressing channelrhodopsin we photo-activated the network in order to assess how excitation delivered in a spatially and temporally precise manner to the inspiratory oscillator influences ongoing breathing rhythms and related muscular activity in urethane-anaesthetized rats. We hypothesized that if an excitatory drive is necessary for rhythmogenesis and burst initiation, photo-activation of preBötC not only will increase respiratory rate, but also entrain it over a wide range of frequencies with fast onset, and have little effect on ongoing respiratory rhythm if a stimulus is delivered during inspiration. Stimulation of preBötC neurons consistently increased respiratory rate and entrained respiration up to fourfold baseline conditions. Furthermore, brief pulses of photostimulation delivered at random phases between inspiratory events robustly and consistently induced phase-independent (Type 0) respiratory reset and recruited inspiratory muscle activity at very short delays (∼100 ms). A 200 ms refractory period following inspiration was also identified. These data provide strong evidence for a fine control of inspiratory activity in the preBötC and provide further evidence that the preBötC network constitutes the fundamental oscillator of inspiratory rhythms. PMID:26010654

  2. Human Salivary Protein Histatin 5 Has Potent Bactericidal Activity against ESKAPE Pathogens

    PubMed Central

    Du, Han; Puri, Sumant; McCall, Andrew; Norris, Hannah L.; Russo, Thomas; Edgerton, Mira

    2017-01-01

    ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanni, Pseudomonas aeruginosa, and Enterobacter species) pathogens have characteristic multiple-drug resistance and cause an increasing number of nosocomial infections worldwide. Peptide-based therapeutics to treat ESKAPE infections might be an alternative to conventional antibiotics. Histatin 5 (Hst 5) is a salivary cationic histidine-rich peptide produced only in humans and higher primates. It has high antifungal activity against Candida albicans through an energy-dependent, non-lytic process; but its bactericidal effects are less known. We found Hst 5 has bactericidal activity against S. aureus (60–70% killing) and A. baumannii (85–90% killing) in 10 and 100 mM sodium phosphate buffer (NaPB), while killing of >99% of P. aeruginosa, 60–80% E. cloacae and 20–60% of E. faecium was found in 10 mM NaPB. Hst 5 killed 60% of biofilm cells of P. aeruginosa, but had reduced activity against biofilms of S. aureus and A. baumannii. Hst 5 killed 20% of K. pneumonia biofilm cells but not planktonic cells. Binding and uptake studies using FITC-labeled Hst 5 showed E. faecium and E. cloacae killing required Hst 5 internalization and was energy dependent, while bactericidal activity was rapid against P. aeruginosa and A. baumannii suggesting membrane disruption. Hst 5-mediated killing of S. aureus was both non-lytic and energy independent. Additionally, we found that spermidine conjugated Hst 5 (Hst5-Spd) had improved killing activity against E. faecium, E. cloacae, and A. baumannii. Hst 5 or its derivative has antibacterial activity against five out of six ESKAPE pathogens and may be an alternative treatment for these infections. PMID:28261570

  3. Human Salivary Protein Histatin 5 Has Potent Bactericidal Activity against ESKAPE Pathogens.

    PubMed

    Du, Han; Puri, Sumant; McCall, Andrew; Norris, Hannah L; Russo, Thomas; Edgerton, Mira

    2017-01-01

    ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanni, Pseudomonas aeruginosa, and Enterobacter species) pathogens have characteristic multiple-drug resistance and cause an increasing number of nosocomial infections worldwide. Peptide-based therapeutics to treat ESKAPE infections might be an alternative to conventional antibiotics. Histatin 5 (Hst 5) is a salivary cationic histidine-rich peptide produced only in humans and higher primates. It has high antifungal activity against Candida albicans through an energy-dependent, non-lytic process; but its bactericidal effects are less known. We found Hst 5 has bactericidal activity against S. aureus (60-70% killing) and A. baumannii (85-90% killing) in 10 and 100 mM sodium phosphate buffer (NaPB), while killing of >99% of P. aeruginosa, 60-80% E. cloacae and 20-60% of E. faecium was found in 10 mM NaPB. Hst 5 killed 60% of biofilm cells of P. aeruginosa, but had reduced activity against biofilms of S. aureus and A. baumannii. Hst 5 killed 20% of K. pneumonia biofilm cells but not planktonic cells. Binding and uptake studies using FITC-labeled Hst 5 showed E. faecium and E. cloacae killing required Hst 5 internalization and was energy dependent, while bactericidal activity was rapid against P. aeruginosa and A. baumannii suggesting membrane disruption. Hst 5-mediated killing of S. aureus was both non-lytic and energy independent. Additionally, we found that spermidine conjugated Hst 5 (Hst5-Spd) had improved killing activity against E. faecium, E. cloacae, and A. baumannii. Hst 5 or its derivative has antibacterial activity against five out of six ESKAPE pathogens and may be an alternative treatment for these infections.

  4. Apolipoprotein A-I Milano exhibits potent antioxidant activity on phospholipid surfaces

    SciTech Connect

    Bielicki, John K.; Oda, Michael N.

    2001-09-21

    Apolipoprotein(apo)A-IMilano and apoA-IParis are rare cysteine variants of apoA-I that produce a HDL deficiency in the absence of cardiovascular disease in humans. This paradox provides the basis for the hypothesis that the cysteine variants posses a beneficial activity not associated with wild-type apoA-I (apoA-IWT). In this study, a unique antioxidant activity of apoA-IMilano and apoA-IParis is described. Antioxidant activity was observed using the monomeric form of the variants and was equally effective before and after initiation of oxidative events. ApoA-IMilano was twice as effective as apoA-IParis in preventing lipoxygenase-mediated oxidation of phospholipids; whereas, apoA-IWT was poorly active. ApoA-IMilano protected phospholipid from reactive oxygen species (ROS) generated via xanthine/xanthine oxidase (X/Xo) but failed to inhibit X/Xo induced reduction of cytochrome C. These results indicate that (1) the antioxidant activity of apoA-IMilano was dependent on phospholipid and (2) the cysteine variant was unable to directly quench ROS in the aqueous phase. There were no differences between lipid-free apoA-IMilano, apoA-IParis, and apoA-IWT in mediating the efflux of cholesterol from macrophages indicating the cysteine variants interacted normally with the ABCA1 efflux pathway. The results indicate that incorporation of a free thiol within an amphipathic alpha helix of apoA-I confers an antioxidant activity distinct from that of apoA-IWT. These studies are the first to relate addition-of-function to rare cysteine mutations in apoA-I primary sequence.

  5. Anti-cariogenic effect of a cetylpyridinium chloride-containing nanoemulsion

    PubMed Central

    Lee, Valerie A.; Karthikeyan, Ramalingam; Rawls, H. Ralph; Amaechi, Bennett T.

    2010-01-01

    Objectives The aim of this pilot study was to investigate the anticaries activity of a nanoemulsion composed of soybean oil, water, Triton X-100 and cetylpyridinium chloride. Methods Tooth blocks (3 mm length × 3 mm width × 2 mm thickness) were cut from smooth surfaces of selected molar teeth using a water-cooled diamond wire saw. The blocks were randomly assigned to three experimental groups, (A) nanoemulsion, (B) 0.12% chlorhexidine gluconate, and (C) no treatment. The formation of dental caries in human tooth enamel was tested using a continuous flow dual-organism (Streptococcus mutans and Lactobacillus casei), biofilm model, which acts as an artificial mouth and simulates the biological and physiological activities observed within the oral environment. Experimental groups A and B were treated with their respective solutions once daily for 30 seconds on each occasion, while group C received no treatment. 10% sucrose was supplied every 6 hours for 6 minutes to simulate meals and pH cycling. The experiment lasted for 5 days, and the tooth blocks were harvested and processed for demineralization assessment using transverse microradiography (TMR). Results For both lesion depth and mineral loss, statistical analysis indicated that Emulsion was significantly lower than Control and Chlorhexidine, and Chlorhexidine was significantly lower than Control. Conclusions We conclude that cetylpyridinium-containing nanoemulsions appear to present a feasible means of preventing the occurrence of early caries. PMID:20600554

  6. Chemical constituents of Phragmanthera austroarabica A. G. Mill and J. A. Nyberg with potent antioxidant activity

    PubMed Central

    Badr, Jihan M.

    2015-01-01

    Background: Phragmanthera austroarabica A.G. Mill. and J. A. Nyberg is a semi parasitic plant belonging to family Loranthaceae. It was collected from Saudi Arabia. It is widely used in folk medicine among the kingdom in treatment of various diseases including diabetes mellitus. Objective: The total alcoholic extract of P. austroarabica collected from Saudi Arabia was investigated for the chemical structure and prominent biological activity of the main constituents. Materials and Methods: Isolation of the active constituents was performed using different chromatographic techniques including column chromatography packed with silica or sephadex and preparative thin layer chromatography. The structures of the isolated compounds were established based on different spectroscopic data as mass spectrum, one-dimensional and two-dimensional nuclear magnetic resonance (correlation spectroscopy, heteronuclear single quantum coherence, and heteronuclear multiple-bond correlation). Results: Phytochemical investigation of the plant resulted in isolation of 12 compounds. The isolated compounds were identified as chrysophanic acid, emodin, chrysophanic acid-8-O-glucoside, emodin-8-O-glucoside, pectolinarigenin, quercetin, dillenetin-3-O-glucoside, catechin, catechin-4’-O-gallate, methyl gallate, lupeol and ursolic acid. All the isolated phenolic compounds revealed significant free radical scavenging activities when tested using 2,2-diphenyl-1-picrylhydrazyl reagent. Conclusion: The antioxidant activities of the isolated compounds can justify the use of P. austroarabica in traditional medicine for treatment of diabetes and verify its possible application as an antihyperglycemic drug. PMID:26692747

  7. Broad and potent antiviral activity of the NAE inhibitor MLN4924.

    PubMed

    Le-Trilling, Vu Thuy Khanh; Megger, Dominik A; Katschinski, Benjamin; Landsberg, Christine D; Rückborn, Meike U; Tao, Sha; Krawczyk, Adalbert; Bayer, Wibke; Drexler, Ingo; Tenbusch, Matthias; Sitek, Barbara; Trilling, Mirko

    2016-02-01

    In terms of infected human individuals, herpesviruses range among the most successful virus families. Subclinical herpesviral infections in healthy individuals contrast with life-threatening syndromes under immunocompromising and immunoimmature conditions. Based on our finding that cytomegaloviruses interact with Cullin Roc ubiquitin ligases (CRLs) in the context of interferon antagonism, we systematically assessed viral dependency on CRLs by utilizing the drug MLN4924. CRL activity is regulated through the conjugation of Cullins with the ubiquitin-like molecule Nedd8. By inhibiting the Nedd8-activating Enzyme (NAE), MLN4924 interferes with Nedd8 conjugation and CRL activity. MLN4924 exhibited pronounced antiviral activity against mouse and human cytomegalovirus, herpes simplex virus (HSV)- 1 (including multi-drug resistant clinical isolates), HSV-2, adeno and influenza viruses. Human cytomegalovirus genome amplification was blocked at nanomolar MLN4924 concentrations. Global proteome analyses revealed that MLN4924 blocks cytomegaloviral replication despite increased IE1 amounts. Expression of dominant negative Cullins assigned this IE regulation to defined Cullin molecules and phenocopied the antiviral effect of MLN4924.

  8. Biological Clues to Potent DNA-Damaging Activities in Food and Flavoring

    PubMed Central

    Hossain, M. Zulfiquer; Gilbert, Samuel F.; Patel, Kalpesh; Ghosh, Soma; Bhunia, Anil K.; Kern, Scott E.

    2013-01-01

    Population differences in age-related diseases and cancer could stem from differences in diet. To characterize DNA strand-breaking activities in selected foods/beverages, flavorings, and some of their constituent chemicals, we used p53R cells, a cellular assay sensitive to such breaks. Substances testing positive included reference chemicals: quinacrine (peak response, 51X) and etoposide (33X); flavonoids: EGCG (19X), curcumin (12X), apigenin (9X), and quercetin (7X); beverages: chamomile (11X), green (21X), and black tea (26X) and coffee (3 to 29X); and liquid smoke (4 to 28X). Damage occurred at dietary concentrations: etoposide near 5 μg/ml produced responses similar to a 1:1000 dilution of liquid smoke, a 1:20 dilution of coffee, and a 1:5 dilution of tea. Pyrogallol-related chemicals and tannins are present in dietary sources and individually produced strong activity: pyrogallol (30X), 3-methoxycatechol (25X), gallic acid (21X), and 1,2,4-benzenetriol (21X). From structure-activity relationships, high activities depended on specific orientations of hydroxyls on the benzene ring. Responses accompanied cellular signals characteristic of DNA breaks such as H2AX phosphorylation. Breaks were also directly detected by comet assay. Cellular toxicological effects of foods and flavorings could guide epidemiologic and experimental studies of potential disease risks from DNA strand-breaking chemicals in diets. PMID:23402862

  9. Potent Chemopreventive/Antioxidant Activity Detected in Common Spices of the Apiaceae Family.

    PubMed

    Jeyabalan, Jeyaprakash; Aqil, Farrukh; Soper, Lisa; Schultz, David J; Gupta, Ramesh C

    2015-01-01

    Spices are used worldwide, particularly in the Asian and Middle Eastern countries, and considered protective against degenerative diseases, including cancer. Here, we report the efficacy of aqueous and non-aqueous extracts of 11 Apiaceae spices for free radical-scavenging activity and to inhibit cytochrome P450s in two separate reactions involving: 1) 4-hydroxy-17ß-estradiol (4E2), DNA, and CuCl2 and 2) 17ß-estradiol, rat liver microsomes, cofactors, DNA and CuCl2. Oxidative DNA adducts resulting from redox cycling of 4E2 were analyzed by (32)P-postlabeling. Aqueous (5 mg/ml) and non-aqueous extracts (6 mg/ml) substantially inhibited (83-98%) formation of DNA adducts in the microsomal reaction. However, in nonmicrosomal reaction, only aqueous extracts showed the inhibitory activity (83-96%). Adduct inhibition was also observed at five-fold lower concentrations of aqueous extracts of cumin (60%) and caraway (90%), and 10-fold lower concentrations of carrot seeds (76%) and ajowan (90%). These results suggests the presence of 2 groups of phytochemicals: polar compounds that have free radical-scavenging activity and lipophilic compounds that selectively inhibit P450 activity associated with estrogen metabolism. Because most of these Apiaceae spices are used widely with no known toxicity, the phytochemicals from the Apiaceae spices used in foods may be potentially protective against estrogen-mediated breast cancer.

  10. Constituents with potent α-glucosidase inhibitory activity from Pueraria lobata (Willd.) ohwi.

    PubMed

    Wang, Xiao-Ling; Jiao, Fu-Rong; Yu, Meng; Lin, Li-Bin; Xiao, Jian; Zhang, Qiang; Wang, Le; Duan, Dong-Zhu; Xie, Gang

    2017-05-01

    One new flavone hydrate named lobatflavate (1), one new chromone named lobatchrosin (2), and one new isoflavone named 3S,4R-tuberosin (3), along with four known isoflavone analogues (4-7), were isolated from the traditional Chinese medicinal plant of Pueraria lobata (Willd.) ohwi. Their structures were elucidated by extensive spectroscopic methods of IR, UV, HR-ESI-MS, 1D and 2D NMR. The absolute configuration of 3 was determined by CD spectrum associated with TD-DFT calculation analysis. All compounds except for 2 were assayed the inhibitory activity against α-glucosidase. Every tested compound was proved to be more active than positive control of acarbose. Of which 1 and 4 showed significant activity with IC50 value of 1.79μM and 23.01μM (IC50 of acarbose was 1998.79μM). Enzyme kinetic experiments revealed that 1 was irreversible whereas 4 was reversible and non-competitive α-glucosidase inhibitors. Moreover, structure-activity relationship was discussed and the docking studies of 1, 3 and 4 were also carried out. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Potent chemopreventive/antioxidant activity detected in common spices of the Apiaceae family

    PubMed Central

    Jeyabalan, Jeyaprakash; Aqil, Farrukh; Soper, Lisa; Schultz, David J.; Gupta, Ramesh C.

    2015-01-01

    Spices are used worldwide, particularly, in the Asian and Middle-Eastern countries and considered protective against degenerative diseases, including cancer. Here, we report the efficacy of aqueous and non-aqueous extracts of eleven Apiaceae spices for free radical-scavenging activity and to inhibit cytochrome P450s in two separate reactions involving: i) 4-hydroxy-17β-estradiol (4E2), DNA and CuCl2 and ii) 17β-estradiol, rat liver microsomes, co-factors, DNA and CuCl2. Oxidative DNA adducts resulting from redox cycling of 4E2 were analyzed by 32P-postlabeling. Aqueous (5 mg/ml) and non-aqueous extracts (6 mg/ml) substantially inhibited (83% – 98%) formation of DNA adducts in the microsomal reaction. However, in non-microsomal reaction, only aqueous extracts showed the inhibitory activity (83% – 96%). Adduct inhibition was also observed at 5-fold lower concentrations of aqueous extracts of cumin (60%) and caraway (90%), and 10-fold lower concentrations of carrot seeds (76%) and ajowan (90%). These results suggests the presence of two groups of phytochemicals - polar compounds that have free radical-scavenging activity, and lipophilic compounds that selectively inhibit P450 activity associated with estrogen metabolism. Because most of these Apiaceae spices are used widely with no known toxicity, the phytochemicals from the Apiaceae spices used in foods may be potentially protective against estrogen-mediated breast cancer. PMID:26381237

  12. Compounds from Sorindeia juglandifolia (Anacardiaceae) exhibit potent anti-plasmodial activities in vitro and in vivo

    PubMed Central

    2012-01-01

    Background Discovering new lead compounds against malaria parasites is a crucial step to ensuring a sustainable global pipeline for effective anti-malarial drugs. As far as we know, no previous phytochemical or pharmacological investigations have been carried out on Sorindeia juglandifolia. This paper describes the results of an anti-malarial activity-driven investigation of the fruits of this Cameroonian plant. Methods Air-dried fruits were extracted by maceration using methanol. The extract was fractionated by flash chromatography followed by column chromatography over silica gel, eluting with gradients of hexane-ethyl acetate mixtures. Resulting fractions and compounds were tested in vitro against the Plasmodium falciparum chloroquine-resistant strain W2, against field isolates of P. falciparum, and against the P. falciparum recombinant cysteine protease falcipain-2. Promising fractions were assessed for acute toxicity after oral administration in mice. One of the promising isolated compounds was assessed in vivo against the rodent malaria parasite Plasmodium berghei. Results The main end-products of the activity-guided fractionation were 2,3,6-trihydroxy benzoic acid (1) and 2,3,6-trihydroxy methyl benzoate (2). Overall, nine fractions tested against P. falciparum W2 and falcipain-2 were active, with IC50 values of 2.3-11.6 μg/ml for W2, and 1.1-21.9 μg/ml for falcipain-2. Purified compounds (1) and (2) also showed inhibitory effects against P. falciparum W2 (IC50s 16.5 μM and 13.0 μM) and falcipain-2 (IC50s 35.4 and 6.1 μM). In studies of P. falciparum isolates from Cameroon, the plant fractions demonstrated IC50 values of 0.14-19.4 μg/ml and compounds (1) and (2) values of 6.3 and 36.1 μM. In vivo assessment of compound (1) showed activity against P. berghei strain B, with mean parasitaemia suppressive dose and curative dose of 44.9 mg/kg and 42.2 mg/kg, respectively. Active fractions were found to be safe in mice after oral administration of 7 g

  13. Negatively charged silver nanoparticles with potent antibacterial activity and reduced toxicity for pharmaceutical preparations

    PubMed Central

    Salvioni, Lucia; Galbiati, Elisabetta; Collico, Veronica; Alessio, Giulia; Avvakumova, Svetlana; Corsi, Fabio; Tortora, Paolo; Prosperi, Davide; Colombo, Miriam

    2017-01-01

    Background The discovery of new solutions with antibacterial activity as efficient and safe alternatives to common preservatives (such as parabens) and to combat emerging infections and drug-resistant bacterial pathogens is highly expected in cosmetics and pharmaceutics. Colloidal silver nanoparticles (NPs) are attracting interest as novel effective antimicrobial agents for the prevention of several infectious diseases. Methods Water-soluble, negatively charged silver nanoparticles (AgNPs) were synthesized by reduction with citric and tannic acid and characterized by transmission electron microscopy, dynamic light scattering, zeta potential, differential centrifuge sedimentation, and ultraviolet–visible spectroscopy. AgNPs were tested with model Gram-negative and Gram-positive bacteria in comparison to two different kinds of commercially available AgNPs. Results In this work, AgNPs with higher antibacterial activity compared to the commercially available colloidal silver solutions were prepared and investigated. Bacteria were plated and the antibacterial activity was tested at the same concentration of silver ions in all samples. The AgNPs did not show any significant reduction in the antibacterial activity for an acceptable time period. In addition, AgNPs were transferred to organic phase and retained their antibacterial efficacy in both aqueous and nonaqueous media and exhibited no toxicity in eukaryotic cells. Conclusion We developed AgNPs with a 20 nm diameter and negative zeta potential with powerful antibacterial activity and low toxicity compared to currently available colloidal silver, suitable for cosmetic preservatives and pharmaceutical preparations administrable to humans and/or animals as needed. PMID:28408822

  14. Potent activation of multiple signalling pathways by C-peptide in opossum kidney proximal tubular cells.

    PubMed

    Al-Rasheed, N M; Meakin, F; Royal, E L; Lewington, A J; Brown, J; Willars, G B; Brunskill, N J

    2004-06-01

    Proinsulin C-peptide is generally believed to be inert without any appreciable biological functions. However, it has been shown to modulate a variety of cellular processes important in the pathophysiology of diabetic complications. We therefore investigated the ability of C-peptide to stimulate intracellular signalling pathways in kidney proximal tubular cells, the altered activation of which may possibly be related to the development of diabetic nephropathy. Extracellular signal-regulated kinase (ERK) and Akt phosphorylation were evaluated by western blotting. ERK activity was measured by in vitro kinase assay. Intracellular Ca(2+) was evaluated by confocal imaging. The membrane and cytosol-associated fractions of protein kinase C (PKC) isoforms were evaluated by western blotting. Proliferation was assessed by thymidine incorporation assay. Using the opossum proximal tubular kidney cell line as a model, we demonstrated that at high picomolar to low nanomolar concentrations, C-peptide stimulates extracellular signal-regulated mitogen-activated kinase (3.3+/-0.1-fold over basal at 3 minutes) and phosphatidylinositol 3-kinase (4.1+/-0.05-fold over basal at 5 minutes). ERK activation was attenuated by pre-treatment with a PKC inhibitor and abolished by pertussis toxin. Elevations of intracellular [Ca(2+)] are seen in response to 5 nmol/l C-peptide with consequent activation of PKC-alpha. Pre-treatment with pertussis toxin abolished PKC-alpha. C-peptide is also a functional mitogen in this cell type, stimulating significantly increased cell proliferation. Proliferation was attenuated by wortmannin and pertussis toxin pre-treatments. None of these effects is reproduced by scrambled C-peptide. This study provides evidence that C-peptide, within physiological concentration ranges, stimulates many signalling pathways in opossum kidney cells.

  15. Negatively charged liposomes show potent adjuvant activity when simply admixed with protein antigens

    PubMed Central

    Yanasarn, Nijaporn; Sloat, Brian R.; Cui, Zhengrong

    2011-01-01

    Liposomes have been investigated extensively as a vaccine delivery system. Herein the adjuvant activities of liposomes with different net surface charges (neutral, positive, or negative) were evaluated when admixed with protein antigens, ovalbumin (OVA, pI = 4.7), Bacillus anthracis protective antigen protein (PA, pI = 5.6), or cationized OVA (cOVA). Mice immunized subcutaneously with OVA admixed with different liposomes generated different antibody responses. Interestingly, OVA admixed with net negatively charged liposomes prepared with DOPA was as immunogenic as OVA admixed with positively charged liposomes prepared with DOTAP. Immunization of mice with the anthrax PA protein admixed with the net negatively charged DOPA liposomes also induced a strong and functional anti-PA antibody response. When the cationized OVA was used as a model antigen, liposomes with net neutral, negative, or positive charges showed comparable adjuvant activities. Immunization of mice with the OVA admixed with DOPA liposomes also induced OVA-specific CD8+ cytotoxic T lymphocyte responses and significantly delayed the growth of OVA-expressing B16-OVA tumors in mice. However, not all net negatively charged liposomes showed a strong adjuvant activity. The adjuvant activity of the negatively charged liposomes may be related to the liposome’s ability (i) to up-regulate the expression of molecules related to the activation and maturation of antigen-presenting cells and (ii) to slightly facilitate the uptake of the antigens by antigen-presenting cells. Simply admixing certain negatively charged liposomes with certain protein antigens of interest may represent a novel platform for vaccine development. PMID:21615153

  16. Malassezia yeasts produce a collection of exceptionally potent activators of the Ah (dioxin) receptor detected in diseased human skin

    PubMed Central

    Magiatis, Prokopios; Pappas, Periklis; Gaitanis, George; Mexia, Nikitia; Melliou, Eleni; Galanou, Maria; Vlachos, Christophoros; Stathopoulou, Konstantina; Skaltsounis, Alexios Leandros; Marselos, Marios; Velegraki, Aristea; Denison, Michael S.; Bassukas, Ioannis D.

    2013-01-01

    Malassezia yeasts are commensal microorganisms which under insufficiently understood conditions can become pathogenic. We have previously shown that specific strains isolated from diseased human skin can preferentially produce agonists of the aryl hydrocarbon receptor (AhR), whose activation has been linked to certain skin diseases. Investigation of skin scale extracts from patients with Malassezia associated diseases demonstrated 10–1000 fold higher AhR activating capacity than control skin extracts. LC/MS/MS analysis of the patients’ extracts revealed the presence of indirubin, 6-formylindolo[3,2-b]carbazole (FICZ), indolo[3,2-b]carbazole (ICZ), malassezin, and pityriacitrin. The same compounds were also identified in 9/12 Malassezia species culture extracts tested, connecting their presence in skin scales with this yeast. Studying the activity of the Malassezia culture-extracts and pure metabolites in HaCaT cells by Reverse Transcriptase Real-Time PCR revealed significant alterations in mRNA levels of the endogenous AhR-responsive genes Cyp1A1, Cyp1B1 and AhRR. Indirubin and FICZ activated AhR in HaCaT and human HepG2 cells with significantly higher, yet transient, potency as compared to the prototypical AhR ligand, dioxin. In loco synthesis of these highly potent AhR inducers by Malassezia yeasts could have a significant impact on skin homeostatic mechanisms and disease development. PMID:23448877

  17. Mutagenic activity in disinfected waters and recovery of the potent bacterial mutagen "MX" from water by XAD resin adsorption

    NASA Astrophysics Data System (ADS)

    Backlund, Peter; Wondergem, Erik; Kronberg, Leif

    Chlorination of humic water generated mutagenic activity in the Ames test. The formation of the potent bacterial mutagen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and mutagenic activity were favoured by acidic chlorination conditions and high chlorine doses. Chlorinated humic waters from different locations differed slightly in the level of mutagenicity as well as in the proportion of activity derived from MX. Chlorination of an industrially polluted surface water with a low content of humic material generated an approximately equal level of mutagenicity (per mg of DOC) as that of chlorinated humic water, but only a minor part (26%) of the activity could be explained by the presence of MX. The mutagenicity and the amount of MX generated were substantially lower when using combined treatment methods (ClO2+Cl2, O3+Cl2) or when substituting chlorine by monochloramine or chlorine dioxide. The recovery of MX by XAD adsorption from water acidified to pH 2 was found to be quantitative.

  18. Purification, sequence, and model structure of charybdotoxin, a potent selective inhibitor of calcium-activated potassium channels.

    PubMed Central

    Gimenez-Gallego, G; Navia, M A; Reuben, J P; Katz, G M; Kaczorowski, G J; Garcia, M L

    1988-01-01

    Charybdotoxin (ChTX), a protein present in the venom of the scorpion Leiurus quinquestriatus var. hebraeus, has been purified to homogeneity by a combination of ion-exchange and reversed-phase chromatography. Polyacrylamide gel electrophoresis, amino acid analysis, and complete amino acid sequence determination of the pure protein reveal that it consists of a single polypeptide chain of 4.3 kDa. Purified ChTX is a potent and selective inhibitor of the approximately 220-pS Ca2+-activated K+ channel present in GH3 anterior pituitary cells and primary bovine aortic smooth muscle cells. The toxin reversibly blocks channel activity by interacting at the external pore of the channel protein with an apparent Kd of 2.1 nM. The primary structure of ChTX is similar to a number of neurotoxins of diverse origin, which suggests that ChTX is a member of a superfamily of proteins that modify ion-channel activities. On the basis of this similarity, the three-dimensional structure of ChTX has been modeled from the known crystal structure of alpha-bungarotoxin. These studies indicate that ChTX is useful as a probe of Ca2+-activated K+-channel function and suggest that the proposed tertiary structure of ChTX may provide insight into the mechanism of channel block. Images PMID:2453055

  19. Synthesis of a novel adamantyl nitroxide derivative with potent anti-hepatoma activity in vitro and in vivo.

    PubMed

    Sun, Jin; Wang, Shan; Bu, Wei; Wei, Meng-Ying; Li, Wei-Wei; Yao, Min-Na; Ma, Zhong-Ying; Lu, Cheng-Tao; Li, Hui-Hui; Hu, Na-Ping; Zhang, En-Hu; Yang, Guo-Dong; Wen, Ai-Dong; Zhu, Xiao-He

    2016-01-01

    In this study, a novel adamantyl nitroxide derivative was synthesized and its antitumor activities in vitro and in vivo were investigated. The adamantyl nitroxide derivative 4 displayed a potent anticancer activity against all the tested human hepatoma cells, especially with IC50 of 68.1 μM in Bel-7404 cells, compared to the positive control 5-FU (IC50=607.7 μM). The significant inhibition of cell growth was also observed in xenograft mouse model, with low toxicity. Compound 4 suppressed the cell migration and invasion, induced the G2/M phase arrest. Further mechanistic studies revealed that compound 4 induced cell death, which was accompanied with damaging mitochondria, increasing the generation of intracellular reactive oxygen species, cleavages of caspase-9 and caspase-3, as well as activations of Bax and Bcl-2. These results confirmed that adamantyl nitroxide derivative exhibited selective antitumor activities via mitochondrial apoptosis pathway in Bel-7404 cells, and would be a potential anticancer agent for liver cancer.

  20. Glycosynthase Mutants of Endoglycosidase S2 Show Potent Transglycosylation Activity and Remarkably Relaxed Substrate Specificity for Antibody Glycosylation Remodeling.

    PubMed

    Li, Tiezheng; Tong, Xin; Yang, Qiang; Giddens, John P; Wang, Lai-Xi

    2016-08-05

    Glycosylation can exert a profound impact on the structures and biological functions of antibodies. Glycosylation remodeling using the endoglycosidase-catalyzed deglycosylation and transglycosylation approach is emerging as a promising platform to produce homogeneous glycoforms of antibodies, but the broad application of this method will require the availability of highly efficient glycosynthase mutants. We describe in this paper a systematic site-directed mutagenesis of an endoglycosidase from Streptococcus pyogenes of serotype M49 (Endo-S2) and the evaluation of the resulting mutants for their hydrolysis and transglycosylation activities. We found that mutations at the Asp-184 residue gave mutants that demonstrated significantly different properties, some possessed potent transglycosylation activity with diminished hydrolysis activity but others did not, which would be otherwise difficult to predict without the comparative study. In contrast to the previously reported Endo-S mutants that are limited to action on complex type N-glycans, the Endo-S2 glycosynthases described here, including D184M and D184Q, were found to have remarkably relaxed substrate specificity and were capable of transferring three major types (complex, high-mannose, and hybrid type) of N-glycans for antibody glycosylation remodeling. In addition, the Endo-S2 glycosynthase mutants were found to be much more active in general than the Endo-S mutants for transglycosylation. The usefulness of these Endo-S2 glycosynthase mutants was exemplified by an efficient glycosylation remodeling of two therapeutic monoclonal antibodies, rituximab and trastuzumab (Herceptin).

  1. Synthesis of a novel adamantyl nitroxide derivative with potent anti-hepatoma activity in vitro and in vivo

    PubMed Central

    Sun, Jin; Wang, Shan; Bu, Wei; Wei, Meng-Ying; Li, Wei-Wei; Yao, Min-Na; Ma, Zhong-Ying; Lu, Cheng-Tao; Li, Hui-Hui; Hu, Na-Ping; Zhang, En-Hu; Yang, Guo-Dong; Wen, Ai-Dong; Zhu, Xiao-He

    2016-01-01

    In this study, a novel adamantyl nitroxide derivative was synthesized and its antitumor activities in vitro and in vivo were investigated. The adamantyl nitroxide derivative 4 displayed a potent anticancer activity against all the tested human hepatoma cells, especially with IC50 of 68.1 μM in Bel-7404 cells, compared to the positive control 5-FU (IC50=607.7 μM). The significant inhibition of cell growth was also observed in xenograft mouse model, with low toxicity. Compound 4 suppressed the cell migration and invasion, induced the G2/M phase arrest. Further mechanistic studies revealed that compound 4 induced cell death, which was accompanied with damaging mitochondria, increasing the generation of intracellular reactive oxygen species, cleavages of caspase-9 and caspase-3, as well as activations of Bax and Bcl-2. These results confirmed that adamantyl nitroxide derivative exhibited selective antitumor activities via mitochondrial apoptosis pathway in Bel-7404 cells, and would be a potential anticancer agent for liver cancer. PMID:27429843

  2. Engineering of a linear inactive analog of human β-defensin 4 to generate peptides with potent antimicrobial activity.

    PubMed

    Sharma, Himanshu; Mathew, Basil; Nagaraj, Ramakrishnan

    2015-06-01

    Human β-defensins (HBDs) are cationic antimicrobial peptides constrained by three disulfide bridges. They have diverse range of functions in the innate immune response. It is of interest to investigate whether linear analogs of defensins can be generated, which possess antimicrobial activity. In this study, we have designed linear peptides with potent antimicrobial activity from an inactive peptide spanning the N-terminus of HBD4. Our results show that l-arginine to d-arginine substitution imparts considerable antimicrobial activity against both bacteria and Candida albicans. Increase in hydrophobicity by fatty acylation of the peptides with myristic acid further enhances their potency. In the presence of high concentrations of salt, antimicrobial activity of the myristoylated peptide with l-arginine is attenuated relatively to a lesser extent as compared with the linear active peptide with d-arginine. Substitution of cysteine with the hydrophobic helix-promoting amino acid α-aminoisobutyric acid favors candidacidal activity but not antibacterial activity. The mechanism of killing by d-arginine substituted unacylated analog involves transient interaction with the bacterial membrane followed by translocation into the cytoplasm without membrane permeabilization. Accumulation of peptides in the cytoplasm can affect various cellular processes that lead to cell death. However, the peptide causes membrane permeabilization in case of C. albicans. Myristoylation results in greater interaction of the peptide chain with the microbial cell surface and causes membrane permeabilization. Results described in the study demonstrate that it is possible to generate highly active linear analogs of defensins by selective introduction of d-amino acids and fatty acids, which could be attractive candidates for development as therapeutic agents.

  3. The antimicrobial peptide pardaxin exerts potent anti-tumor activity against canine perianal gland adenoma

    PubMed Central

    Pan, Chieh-Yu; Lin, Chao-Nan; Chiou, Ming-Tang; Yu, Chao Yuan; Chen, Jyh-Yih; Chien, Chi-Hsien

    2015-01-01

    Pardaxin is an antimicrobial peptide of 33 amino acids, originally isolated from marine fish. We previously demonstrated that pardaxin has anti-tumor activity against murine fibrosarcoma, both in vitro and in vivo. In this study, we examined the anti-tumor activity, toxicity profile, and maximally-tolerated dose of pardaxin treatment in dogs with different types of refractory tumor. Local injection of pardaxin resulted in a significant reduction of perianal gland adenoma growth between 28 and 38 days post-treatment. Surgical resection of canine histiocytomas revealed large areas of ulceration, suggesting that pardaxin acts like a lytic peptide. Pardaxin treatment was not associated with significant variations in blood biochemical parameters or secretion of immune-related proteins. Our findings indicate that pardaxin has strong therapeutic potential for treating perianal gland adenomas in dogs. These data justify the veterinary application of pardaxin, and also provide invaluable information for veterinary medicine and future human clinical trials. PMID:25544775

  4. Spice oil cinnamaldehyde exhibits potent anticandidal activity against fluconazole resistant clinical isolates.

    PubMed

    Shreaz, Sheikh; Bhatia, Rimple; Khan, Neelofar; Muralidhar, Sumathi; Basir, Seemi F; Manzoor, Nikhat; Khan, Luqman Ahmad

    2011-10-01

    Fluconazole resistance is becoming an important clinical concern. We studied the in vitro effects of cinnamaldehyde against 18 fluconazole-resistant Candida isolates. MIC(90) of cinnamaldehyde against different Candida isolates ranged 100-500 μg/ml. Growth and sensitivity of the organisms were significantly affected by cinnamaldehyde at different concentrations. The rapid irreversible action of this compound on fungal cells suggested membrane-located targets for its action. Insight studies to mechanism suggested that cinnamaldehyde exerts its antifungal activity by targeting sterol biosynthesis and plasma membrane ATPase activity. Inhibition of H(+) (-)ATPase leads to intracellular acidification and cell death. Toxicity against H9c2 rat cardiac myoblasts was studied to exclude the possibility of further associated cytotoxicity. The observed selectively fungicidal characteristics against fluconazole-resistant Candida isolates signify a promising candidature of this essential oil as an antifungal agent in treatments for candidosis.

  5. A selective TrkB agonist with potent neurotrophic activities by 7,8-dihydroxyflavone

    PubMed Central

    Jang, Sung-Wuk; Liu, Xia; Yepes, Manuel; Shepherd, Kennie R.; Miller, Gary W.; Liu, Yang; Wilson, W. David; Xiao, Ge; Blanchi, Bruno; Sun, Yi E.; Ye, Keqiang

    2010-01-01

    Brain-derived neurotrophic factor (BDNF), a cognate ligand for the tyrosine kinase receptor B (TrkB) receptor, mediates neuronal survival, differentiation, synaptic plasticity, and neurogenesis. However, BDNF has a poor pharmacokinetic profile that limits its therapeutic potential. Here we report the identification of 7,8-dihydroxyflavone as a bioactive high-affinity TrkB agonist that provokes receptor dimerization and autophosphorylation and activation of downstream signaling. 7,8-Dihydroxyflavone protected wild-type, but not TrkB-deficient, neurons from apoptosis. Administration of 7,8-dihydroxyflavone to mice activated TrkB in the brain, inhibited kainic acid-induced toxicity, decreased infarct volumes in stroke in a TrkB-dependent manner, and was neuroprotective in an animal model of Parkinson disease. Thus, 7,8-dihydroxyflavone imitates BDNF and acts as a robust TrkB agonist, providing a powerful therapeutic tool for the treatment of various neurological diseases. PMID:20133810

  6. Potent adjuvantic activity of a CCR1-agonistic bis-quinoline.

    PubMed

    Ukani, Rehman; Lewis, Tyler C; Day, Timothy P; Wu, Wenyan; Malladi, Subbalakshmi S; Warshakoon, Hemamali J; David, Sunil A

    2012-01-01

    A bis-quinoline compound, (7-chloro-N-(4-(7-chloroquinolin-4-ylamino)butyl)quinolin-4-amine; RE-660) was found to have C-C chemokine receptor type 1 (CCR1)-agonistic properties. RE-660 displayed strong adjuvantic activity in mice when co-administered with bovine α-lactalbumin used as a model subunit protein antigen. RE-660 evoked a balanced Th1 (IgG2)/Th2 (IgG1) antibody profile, and the quality of antibodies elicited by the bis-quinoline was found to be superior to that evoked by glucopyranosyl lipid A by surface plasmon resonance experiments. No evidence of proinflammatory activity was observed in human blood ex vivo models. In preliminary acute toxicity studies, the compound was found to be of lower toxicity than chloroquine in mice, and was non-mutagenic in an Ames screen. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Fe(III)-TAML activator: a potent peroxidase mimic for chemiluminescent determination of hydrogen peroxide.

    PubMed

    Vdovenko, Marina M; Demiyanova, Alexandra S; Kopylov, Kirill E; Sakharov, Ivan Yu

    2014-07-01

    Efforts to replace native peroxidase with its low molecular weight alternatives have stimulated a search for peroxidase mimetics. Herein we describe the oxidation of luminol with hydrogen peroxide catalyzed by commercially available Fe(III)-TAML activator 1a, which was shown to be a more active catalyst than hemin. At Fe(III)-TAML activator 1a use in chemiluminescent assay for H2O2 determination the detection limit value (3σ) of 5×10(-8)M was similar to the detection limit obtained with horseradish peroxidase (1×10(-7)M) and significantly lower than that obtained in the presence of hemin (6×10(-7)M). The linear ranges (R(2)=0.98) of the assay were 6×10(-8)-1×10(-6)M and 6×10(-7)-1×10(-6)M H2O2 for Fe(III)-TAML 1a and hemin, respectively. The CV values for Fe(III)-TAML 1a-based assay measured within the working range varied from 1.0% to 3.7% (n=4), whereas in the case of hemin -5.0% to 9.7% (n=4). Moreover, the sensitivity of Fe(III)-TAML 1a-based method was 56 and 5 times higher than that of hemin- and HRP-based methods, respectively. The obtained results open good perspectives to apply Fe(III)-TAML activator 1a in CL analytical methods instead of hemin, a traditionally used peroxidase mimetic.

  8. Characterization of the potent in vitro and in vivo antimalarial activities of ionophore compounds.

    PubMed Central

    Gumila, C; Ancelin, M L; Delort, A M; Jeminet, G; Vial, H J

    1997-01-01

    Large-scale in vitro screening of different types of ionophores previously pinpointed nine compounds that were very active and selective in vitro against Plasmodium falciparum; their in vitro and in vivo antimalarial effects were further studied. Addition of the ionophores to synchronized P. falciparum suspensions revealed that all P. falciparum stages were sensitive to the drugs. However, the schizont stages were three- to ninefold more sensitive, and 12 h was required for complete parasite clearance. Pretreatment of healthy erythrocytes with toxic doses of ionophores for 24 to 48 h showed that the activity was not due to an irreversible effect on the host erythrocyte. No preferential ionophore adsorption in infected or uninfected erythrocytes occurred. On the other hand, ionophore molecules strongly bound to serum proteins since increasing the serum concentration from 2 to 50% led to almost a 25-fold parallel increase in the ionophore 50% inhibitory concentration. Mice infected with the malaria parasites Plasmodium vinckei petteri or Plasmodium chabaudi were successfully treated with eight ionophores in a 4-day suppressive test. The 50% effective dose after intraperitoneal administration ranged from 0.4 to 4.1 mg/kg of body weight, and the therapeutic indices were about 5 for all ionophores except monensin A methyl ether, 5-bromo lasalocid A, and gramicidin D, whose therapeutic indices were 12, 18, and 344, respectively. These three compounds were found to be curative, with no recrudescence. Gramicidin D, which presented impressive antimalarial activity, requires parenteral administration, while 5-bromo lasalocid A has the major advantage of being active after oral administration. Overall, the acceptable levels of toxicity and the good in vivo therapeutic indices in the rodent model highlight the interesting potential of these ionophores for the treatment of malaria in higher animals. PMID:9055986

  9. New glutaramic acid derivatives with potent competitive and specific cholecystokinin-antagonistic activity.

    PubMed

    Makovec, F; Chistè, R; Bani, M; Pacini, M A; Setnikar, I; Rovati, L A

    1985-01-01

    New glutaramic acid derivatives were evaluated for anti-cholecystokinin (CCK) activity in vitro on guinea pig gallbladder. The compounds are competitive and specific CCK-antagonists, causing a parallel right shift of the cumulative dose-response curve of the agonist. The affinity for the binding site of the CCK-receptor for some of these compounds was hundreds of times higher than that of pro-glumide, the model compound.

  10. Alkylidene Oxapenem β-Lactamase Inhibitors Revisited: Potent Broad Spectrum Activity but New Stability Challenges

    PubMed Central

    2014-01-01

    We present a comprehensive study of C6-alkylidene containing oxapenems. We show that this class of β-lactamase inhibitors possesses an unprecedented spectrum with activity against class A, C, and D enzymes. Surprisingly, this class of compounds displayed significant photolytic instability in addition to the known hydrolytic instability. Quantum mechanical calculations were used to develop models to predict the stability of new analogues. PMID:25147614

  11. Alkylidene Oxapenem β-Lactamase Inhibitors Revisited: Potent Broad Spectrum Activity but New Stability Challenges.

    PubMed

    Miller, Matthew D; Kale, Manoj; Reddy, Kishore; Tentarelli, Sharon; Zambrowski, Mark; Zhang, Minli; Palmer, Tiffany; Breen, John; Lahiri, Sushmita; Shirude, Pravin S; Verheijen, Jeroen C

    2014-08-14

    We present a comprehensive study of C6-alkylidene containing oxapenems. We show that this class of β-lactamase inhibitors possesses an unprecedented spectrum with activity against class A, C, and D enzymes. Surprisingly, this class of compounds displayed significant photolytic instability in addition to the known hydrolytic instability. Quantum mechanical calculations were used to develop models to predict the stability of new analogues.

  12. Structural Basis of Binding and Rationale for the Potent Urease Inhibitory Activity of Biscoumarins

    PubMed Central

    Lodhi, Muhammad Arif; Choudhary, Muhammad Iqbal; Lodhi, Atif; Ul-Haq, Zaheer; Jalil, Saima; Nawaz, Sarfraz Ahmad; Khan, Khalid Mohammed; Iqbal, Sajid; Rahman, Atta-ur

    2014-01-01

    Urease belongs to a family of highly conserved urea-hydrolyzing enzymes. A common feature of these enzymes is the presence of two Lewis acid nickel ions and reactive cysteine residue in the active sites. In the current study we examined a series of biscoumarins 1–10 for their mechanisms of inhibition with the nickel containing active sites of Jack bean and Bacillus pasteurii ureases. All these compounds competitively inhibited Jack bean urease through interaction with the nickel metallocentre, as deduced from Michaelis-Menten kinetics, UV-visible absorbance spectroscopic, and molecular docking simulation studies. Some of the compounds behaved differently in case of Bacillus pasteurii urease. We conducted the enzyme kinetics, UV-visible spectroscopy, and molecular docking results in terms of the known protein structure of the enzyme. We also evaluated possible molecular interpretations for the site of biscoumarins binding and found that phenyl ring is the major active pharmacophore. The excellent in vitro potency and selectivity profile of the several compounds described combined with their nontoxicity against the human cells and plants suggest that these compounds may represent a viable lead series for the treatment of urease associated problems. PMID:25295281

  13. Structural basis of binding and rationale for the potent urease inhibitory activity of biscoumarins.

    PubMed

    Lodhi, Muhammad Arif; Shams, Sulaiman; Choudhary, Muhammad Iqbal; Lodhi, Atif; Ul-Haq, Zaheer; Jalil, Saima; Nawaz, Sarfraz Ahmad; Khan, Khalid Mohammed; Iqbal, Sajid; Rahman, Atta-ur

    2014-01-01

    Urease belongs to a family of highly conserved urea-hydrolyzing enzymes. A common feature of these enzymes is the presence of two Lewis acid nickel ions and reactive cysteine residue in the active sites. In the current study we examined a series of biscoumarins 1-10 for their mechanisms of inhibition with the nickel containing active sites of Jack bean and Bacillus pasteurii ureases. All these compounds competitively inhibited Jack bean urease through interaction with the nickel metallocentre, as deduced from Michaelis-Menten kinetics, UV-visible absorbance spectroscopic, and molecular docking simulation studies. Some of the compounds behaved differently in case of Bacillus pasteurii urease. We conducted the enzyme kinetics, UV-visible spectroscopy, and molecular docking results in terms of the known protein structure of the enzyme. We also evaluated possible molecular interpretations for the site of biscoumarins binding and found that phenyl ring is the major active pharmacophore. The excellent in vitro potency and selectivity profile of the several compounds described combined with their nontoxicity against the human cells and plants suggest that these compounds may represent a viable lead series for the treatment of urease associated problems.

  14. Agents related to a potent activator of the acetylcholine receptor of Electrophorus electricus.

    PubMed

    Wassermann, N H; Erlanger, B F

    1981-09-01

    The synthesis of a number of compounds related to trans-3,3'-bis[alpha-(trimethylammonium)methyl]azobenzene dibromide (trans-3,3'-BisQ) (1) is described. Among the compounds are: [14C]-trans-3,3'-BisQ (1) diiodide, cis-3,3'-BisQ (2) dibromide, the trans-2,2' (7) and 4,4' (11) isomers of BisQ, 2,2', (12), 3,3' (13) and 4,4' (14) isomers of bis-benzyldimethylammonium analogues, and related compounds in which the azo bridge between the two aromatic rings is replaced by diketo and amide bridges. Of them all trans-3,3'-BisQ (1) was the most active cholinergic compound in the electroplax system of Electrophorus electricus; the pure cis isomer (2) was without activity. Intermediate activities were found for some of the other compounds and others were inhibitors. The relationship of the structure of these agents to a proposed conformation and topography of the binding site of the acetylcholine receptor (AChR) is discussed.

  15. Modified pectin from Theobroma cacao induces potent pro-inflammatory activity in murine peritoneal macrophage.

    PubMed

    Amorim, Juliana C; Vriesmann, Lucia Cristina; Petkowicz, Carmen L O; Martinez, Glaucia Regina; Noleto, Guilhermina R

    2016-11-01

    In vitro effects of acetylated pectin (OP) isolated from cacao pod husks (Theobroma cacao L.), its partially deacetylated and de-esterified form (MOP), and a commercial homogalacturonan (PG) were investigated on murine peritoneal macrophages. MOP stood out among the studied pectins. After 48h of incubation, compared with the control group, it was able to promote significant macrophage morphological differentiation from resident to activated stage and also stimulated nitric oxide production, which reached a level of 85% of that of LPS stimulus. In the presence of the highest tested concentration of MOP (200μg·mL(-1)), the levels of the cytokines TNF-α (6h) and IL-12 and IL-10 (48h) increased substantially in relation to untreated cells. Our results show that the partial deacetylation and de-esterification of pectin extracted from cacao pod husks (T. cacao L.) produced a polymer with greater ability than its native form to activate macrophages to a cytotoxic phenotype. Like this, they provide the possibility of a therapeutic application to MOP, which could lead to a decreased susceptibility to microbial infection besides antitumor activity. Additionally, the present results also corroborate with the proposition of that the chemical modifications of the biopolymers can result in an improved molecule with new possibilities of application. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Fungal metabolites of xanthohumol with potent antiproliferative activity on human cancer cell lines in vitro.

    PubMed

    Tronina, Tomasz; Bartmańska, Agnieszka; Filip-Psurska, Beata; Wietrzyk, Joanna; Popłoński, Jarosław; Huszcza, Ewa

    2013-04-01

    Xanthohumol (1) and xanthohumol D (2) were isolated from spent hops. Isoxanthohumol (3) was obtained from xanthohumol by isomerisation in alkaline solution. Six metabolites were obtained as a result of transformation of xanthohumol (1) by selected fungal cultures. Their structures were established on the basis of their spectral data. One of them: 2″-(2'''-hydroxyisopropyl)-dihydrofurano-[4″,5″:3',4']-4',2-dihydroxy-6'-methoxy-α,β-dihydrochalcone (6) has not been previously reported in the literature. The antioxidant properties of hops flavonoids and xanthohumol derivatives were investigated using the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The effects of these compounds on proliferation of MCF-7, PC-3 and HT-29 human cancer cell lines were determined by the SRB assay. With the exception of one metabolite, all tested compounds showed antiproliferative activity against the tested human cancer lines. α,β-Dihydroxanthohumol (4), obtained through the biotransformation of xanthohumol, showed higher antiproliferative activity against MCF-7 human breast carcinoma cell line than cisplatin, a widely used anticancer therapeutic agent, and a comparably high activity against PC-3 human prostate cancer cell line.

  17. The highly lipophilic DNA topoisomerase I inhibitor DB-67 displays elevated lactone levels in human blood and potent anticancer activity.

    PubMed

    Bom, D; Curran, D P; Zhang, J; Zimmer, S G; Bevins, R; Kruszewski, S; Howe, J N; Bingcang, A; Latus, L J; Burke, T G

    2001-07-06

    The novel silatecan 7-t-butyldimethylsilyl-10-hydroxycamptothecin (DB-67) is 25- to 50-times more lipophilic than camptothecin and readily incorporates into lipid bilayers. Using the method of fluorescence anisotropy titration, we determined that DB-67 bound to small unilamellar vesicles composed of dilaurylphosphatidylcholine (DLPC) with an association constant (K value) of 5000 M(-1). This association constant is significantly higher than the K(DLPC) value observed for camptothecin (K(DLPC) value of 110 M(-1)). Using HPLC methods, we demonstrated that the presence of liposomal membranes readily stabilize the lactone form of DB-67. At drug and lipid concentrations of 10 microM and 0.3 mM, respectively, the lactone form of DB-67 persisted in liposome suspension after 3 h of incubation at 37 degrees C. Thus an advantage of a liposomal formulation of DB-67 is that the presence of lipid bilayers assists with stabilizing the key pharmacophore of the agent. The highly lipophilic character of DB-67, in combination with its 10-hydroxy moiety (which functions to enhance lactone stability in the presence of human serum albumin), results in DB-67 having superior stability in human blood with a percent lactone at equilibrium value of 30 [Cancer Res. 59 (1999) 4898; J. Med. Chem. 43 (2000) 3970]. Potent cytotoxicities against a broad range of cancer cells were observed for DB-67, indicating that DB-67 is of comparable potency to camptothecin. The impressive human blood stability and cytotoxicity profiles for DB-67 indicate it is an excellent candidate for comprehensive in vivo pharmacological and efficacy studies. Based on these promising attributes, DB-67 is currently being developed under the NCI RAID program. Due to its potent anti-topoisomerase I activity and its intrinsic blood stability, DB-67 appears as an attractive novel camptothecin for clinical development.

  18. Anti-cariogenic properties of a water-soluble extract from cacao.

    PubMed

    Ito, Kyoko; Nakamura, Yuko; Tokunaga, Takahisa; Iijima, Daisuke; Fukushima, Kazuo

    2003-12-01

    The addition of a water-soluble extract from cacao-extracted powder (CEPWS) to a cariogenic model food, a white chocolate-like diet that contains 35% sucrose, significantly reduced caries scores in SPF rats infected with Streptococcus sobrinus 6715, compared to control rats fed a white chocolate-like diet. CEPWS markedly inhibited water-insoluble glucan (WIG) synthesis through crude glucosyltransferases (GTFs) from Streptococcus sobrinus B13N in vitro. GTF-inhibitor(s) in CEPWS was prepared through three-step fractionation, and was termed CEPWS-BT, which is a high molecular weight (>10 kDa) heat-stable matrix of sugar, protein, and polyphenol. When the inhibitory effect of CEPWS-BT on glucan synthesis was examined using the purified GTF-I, GTF-T, and GTF-U enzymes from S. sobrinus B13N, significant reduction in GTF-I and GTF-T activity as a result of adding CEPWS-BT at low concentrations was observed. These results suggest that the addition of CEPWS to cariogenic food could be useful in controlling dental caries.

  19. A New Octadecenoic Acid Derivative from Caesalpinia gilliesii Flowers with Potent Hepatoprotective Activity

    PubMed Central

    Osman, Samir M.; El-Haddad, Alaadin E.; El-Raey, Mohamed A.; Abd El-Khalik, Soad M.; Koheil, Mahmoud A.; Wink, Michael

    2016-01-01

    Background: Caesalpinia gilliesii Hook is an ornamental shrub with showy yellow flowers. It was used in folk medicine due to its contents of different classes of secondary metabolites. In our previous study, dichloromethane extract of C. gilliesii flowers showed a good antioxidant activity. Aim of the Study: Isolation and identification of bioactive hepatoprotective compounds from C. gilliesii flowers dichloromethane fraction. Materials and Methods: The hepatoprotective activity of dichloromethane fraction and isolated compounds were studied in CCl4-intoxicated rat liver slices by measuring liver injury markers (alanine aminotransferase, aspartate aminotransferase and glutathione [GSH]). All compounds were structurally elucidated on the basis of electron ionization-mass spectrometry, one- and two-dimensional nuclear magnetic resonance. Results: A new 12,13,16-trihydroxy-14(Z)-octadecenoic acid was identified in addition to the known β-sitosterol-3-O-butyl, daucosterol, isorhamnetin, isorhamnetin-3-O-rhamnoside, luteolin-7,4’-dimethyl ether, genistein-5-methyl ether, luteolin-7-O-rhamnoside, isovanillic acid, and p-methoxybenzoic acid. Dichloromethane fraction and isorhamnetin were able to significantly protect the liver against intoxication. Moreover, the dichloromethane fraction and the isolated phytosterols induced GSH above the normal level. Conclusion: The hepatoprotective activity of C. gilliesii may be attributed to its high content of phytosterols and phenolic compounds. SUMMARY Bioactive Hepatoprotective phytosterols and phenolics from chloroform extract of Caesalpinia gilliesii Abbreviations used: ALT: Alanine Aminotransferase; AST: Aspartate aminotransferase; GSH: Glutathione; SC50: Scavenging Capacity 50 (SC 50); COSY: Correlation spectroscopy; NMR: Nuclear Magnetic Resonance; CC: Column chromatography; EI-MS: Electron-impact mass spectrometry; HSQC: Heteronuclear single-quantum correlation. PMID:27563221

  20. Potent Antidiabetic Activity and Metabolite Profiling of Melicope Lunu-ankenda Leaves.

    PubMed

    Al-Zuaidy, Mizher Hezam; Hamid, Azizah Abdul; Ismail, Amin; Mohamed, Suhaila; Abdul Razis, Ahmad Faizal; Mumtaz, Muhammad Waseem; Salleh, Syafiq Zikri

    2016-05-01

    Diabetes mellitus is normally characterized by chronic hyperglycemia associated with disturbances in the fat, carbohydrate, and protein metabolism. There is an increasing trend of using natural products instead of synthetic agents as alternative therapy for disorders due to their fewer side effects. In this study, antidiabetic and antioxidant activities of different Melicope lunu-ankenda (ML) ethanolic extracts were evaluated using inhibition of α-glucosidase and 2,2-diphenyl-l-picrylhydrazyl (DPPH) radicals scavenging activity, respectively; whereas, proton nuclear magnetic resonance ((1) H NMR) and ultra-high performance liquid chromatography-tandem mass spectrometric (UHPLC-MS/MS) techniques were used for metabolite profiling of ML leaf extracts at different concentrations of ethanol and water. Sixty percent of ethanolic ML extract showed highest inhibitory effect against α-glucosidase enzyme (IC50 of 37 μg/mL) and DPPH scavenging activity (IC50 of 48 μg/mL). Antidiabetic effect of ML extracts was also evaluated in vivo and it was found that the high doses (400 mg/Kg BW) of ML extract exhibited high suppression in fasting blood glucose level by 62.75%. The metabolites responsible for variation among ML samples with variable ethanolic levels have been evaluated successfully using (1) H-NMR-based metabolomics. The principal component analysis (PCA) and partial least squares(PLS) analysis scores depicted clear and distinct separations into 4 clusters representing the 4 ethanolic concentrations by PC1 and PC2, with an eigenvalue of 69.9%. Various (1) H-NMR chemical shifts related to the metabolites responsible for sample difference were also ascribed. The main bioactive compounds identified attributing toward the separation included: isorhamnetin, skimmianine, scopoletin, and melicarpinone. Hence, ML may be used as promising medicinal plant for the development of new functional foods, new generation antidiabetic drugs, as a single entity phytomedicine or in

  1. Highly Potent, Water Soluble Benzimidazole Antagonist for Activated (alpha)4(beta)1 Integrin

    SciTech Connect

    Carpenter, R D; Andrei, M; Lau, E Y; Lightstone, F C; Liu, R; Lam, K S; Kurth, M J

    2007-08-29

    The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin, activated constitutively in lymphoma, can be targeted with the bisaryl urea peptidomimetic antagonist 1 (LLP2A). However, concerns on its preliminary pharmacokinetic (PK) profile provided an impetus to change the pharmacophore from a bisaryl urea to a 2-arylaminobenzimidazole moiety resulting in improved solubility while maintaining picomolar potency [5 (KLCA4); IC{sub 50} = 305 pM]. With exceptional solubility, this finding has potential for improving PK to help diagnose and treat lymphomas.

  2. Novel composite plastics containing silver(I) acylpyrazolonato additives display potent antimicrobial activity by contact.

    PubMed

    Marchetti, Fabio; Palmucci, Jessica; Pettinari, Claudio; Pettinari, Riccardo; Condello, Francesca; Ferraro, Stefano; Marangoni, Mirko; Crispini, Alessandra; Scuri, Stefania; Grappasonni, Iolanda; Cocchioni, Mario; Nabissi, Massimo; Chierotti, Michele R; Gobetto, Roberto

    2015-01-07

    New silver(I) acylpyrazolonato derivatives displaying a mononuclear, polynuclear, or ionic nature, as a function of the ancillary azole ligands used in the synthesis, have been fully characterized by thermal analysis, solution NMR spectroscopy, solid-state IR and NMR spectroscopies, and X-ray diffraction techniques. These derivatives have been embedded in polyethylene (PE) matrix, and the antimicrobial activity of the composite materials has been tested against three bacterial strains (E. coli, P. aeruginosa, and S. aureus): Most of the composites show antimicrobial action comparable to PE embedded with AgNO3 . Tests by contact and release tests for specific migration of silver from PE composites clearly indicate that, at least in the case of the PE, for composites containing polynuclear silver(I) additives, the antimicrobial action is exerted by contact, without release of silver ions. Moreover, PE composites can be re-used several times, displaying the same antimicrobial activity. Membrane permeabilization studies and induced reactive oxygen species (ROS) generation tests confirm the disorganization of bacterial cell membranes. The cytotoxic effect, evaluated in CD34(+) cells by MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazoliumbromide) and CFU (colony forming units) assays, indicates that the PE composites do not induce cytotoxicity in human cells. Studies of ecotoxicity, based on the test of Daphnia magna, confirm tolerability of the PE composites by higher organisms and exclude the release of Ag(+) ions in sufficient amounts to affect water environment.

  3. Impurities contained in antifungal drug ketoconazole are potent activators of human aryl hydrocarbon receptor.

    PubMed

    Grycová, Aneta; Dořičáková, Aneta; Dvořák, Zdeněk

    2015-12-03

    Antifungal drug ketoconazole is a mixture of (+)/(-) cis-enantiomers, which also contains several impurities. Ketoconazole was identified as an activator of aryl hydrocarbon receptor AhR by three independent research teams. In the current paper we demonstrate that impurities contained in ketoconazole preparations are strong activators of human AhR and inducers of CYP1A1. Impurity IMP-C had similar potency (EC50), but 10-15 times higher efficacy (magnitude of induction) towards AhR, comparing to (+)-ketoconazole, as revealed by gene reporter assay in AZ-AHR stably transfected cells. Impurities IMP-B and IMP-C, and in lesser extent IMP-E, induced a formation of AhR-DNA complex, as demonstrated by electromobility shift assay EMSA. Impurities IMP-C and IMP-E dose-dependently induced CYP1A1 mRNA after 24 h, and their effects were comparable to those by (+)-ketoconazole. The level of CYP1A1 protein in HepG2 cells was strongly increased by IMP-C after 48h. In conclusion, our data further elucidated molecular effects of ketoconazole towards AhR signaling pathway, with possible implications in ketoconazole role in skin chemoprevention and/or damage, involving AhR.

  4. Synthesis, Docking and Biological Activities of Novel Hybrids Celecoxib and Anthraquinone Analogs as Potent Cytotoxic Agents

    PubMed Central

    Almutairi, Maha S.; Hegazy, Gehan H.; Haiba, Mogedda E.; Ali, Hamed I.; Khalifa, Nagy M.; Soliman, Abd El-mohsen M.

    2014-01-01

    Herein, novel hybrid compounds of celecoxib and 2-aminoanthraquinone derivatives have been synthesized using condensation reactions of celecoxib with 2-aminoanthraquinone derivatives or 2-aminoanthraquinon with celecoxib derivatives. Celecoxib was reacted with different acid chlorides, 2-chloroethylisocyanate and bis (2-chloroethyl) amine hydrochloride. These intermediates were then reacted with 2-aminoanthraquinone. Also the same different acid chlorides and 2-chloroethylisocyanate were reacted with 2-aminoanthraquinone and the resulting intermediates were reacted with celecoxib to give isomers for the previous compounds. The antitumor activities against hepatic carcinoma tumor cell line (HEPG2) have been investigated in vitro, and all these compounds showed promising activities, especially compound 3c, 7, and 12. Flexible docking studies involving AutoDock 4.2 was investigated to identify the potential binding affinities and the mode of interaction of the hybrid compounds into two protein tyrosine kinases namely, SRC (Pp60v-src) and platelet-derived growth factor receptor, PDGFR (c-Kit). The compounds in this study have a preferential affinity for the c-Kit PDGFR PTK over the non-receptor tyrosine kinase SRC (Pp60v-src). PMID:25490139

  5. Potent obatoclax cytotoxicity and activation of triple death mode killing across infant acute lymphoblastic leukemia

    PubMed Central

    Urtishak, Karen A.; Edwards, Alena Y. Z.; Wang, Li-San; Hudome, Amanda; Robinson, Blaine W.; Barrett, Jeffrey S.; Cao, Kajia; Cory, Lori; Moore, Jonni S.; Bantly, Andrew D.; Yu, Qian-Chun; Chen, I-Ming L.; Atlas, Susan R.; Willman, Cheryl L.; Kundu, Mondira; Carroll, Andrew J.; Heerema, Nyla A.; Devidas, Meenakshi; Hilden, Joanne M.; Dreyer, ZoAnn E.; Hunger, Stephen P.; Reaman, Gregory H.; Felix, Carolyn A.

    2013-01-01

    Survival in infants younger than 1 year who have acute lymphoblastic leukemia (ALL) is inferior whether MLL is rearranged (R) or germline (G). MLL translocations confer chemotherapy resistance, and infants experience excess complications. We characterized in vitro sensitivity to the pan-antiapoptotic BCL-2 family inhibitor obatoclax mesylate in diagnostic leukemia cells from 54 infants with ALL/bilineal acute leukemia because of the role of prosurvival BCL-2 proteins in resistance, their imbalanced expression in infant ALL, and evidence of obatoclax activity with a favorable toxicity profile in early adult leukemia trials. Overall, half maximal effective concentrations (EC50s) were lower than 176 nM (the maximal plasma concentration [Cmax] with recommended adult dose) in 76% of samples, whether in MLL-AF4, MLL-ENL, or other MLL-R or MLL-G subsets, and regardless of patients’ poor prognostic features. However, MLL status and partner genes correlated with EC50. Combined approaches including flow cytometry, Western blot, obatoclax treatment with death pathway inhibition, microarray analyses, and/or electron microscopy indicated a unique killing mechanism involving apoptosis, necroptosis, and autophagy in MLL-AF4 ALL cell lines and primary MLL-R and MLL-G infant ALL cells. This in vitro obatoclax activity and its multiple killing mechanisms across molecular cytogenetic subsets provide a rationale to incorporate a similarly acting compound into combination strategies to combat infant ALL. PMID:23393050

  6. Cannabinoid derivatives exert a potent anti-myeloma activity both in vitro and in vivo.

    PubMed

    Barbado, M Victoria; Medrano, Mayte; Caballero-Velázquez, Teresa; Álvarez-Laderas, Isabel; Sánchez-Abarca, Luis Ignacio; García-Guerrero, Estefania; Martín-Sánchez, Jesús; Rosado, Iván Valle; Piruat, José Ignacio; Gonzalez-Naranjo, Pedro; Campillo, Nuria Eugenia; Páez, Juan Antonio; Pérez-Simón, José Antonio

    2017-02-01

    Although hematopoietic and immune system show high levels of the cannabinoid receptor CB2, the potential effect of cannabinoids on hematologic malignancies has been poorly determined. Here we have investigated their anti-tumor effect in multiple myeloma (MM). We demonstrate that cannabinoids induce a selective apoptosis in MM cell lines and in primary plasma cells of MM patients, while sparing normal cells from healthy donors, including hematopoietic stem cells. This effect was mediated by caspase activation, mainly caspase-2, and was partially prevented by a pan-caspase inhibitor. Their pro-apoptotic effect was correlated with an increased expression of Bax and Bak, a decrease of Bcl-xL and Mcl-1, a biphasic response of Akt/PKB and an increase in the levels of ceramide in MM cells. Inhibition of ceramide synthesis partially prevented apoptosis, indicating that these sphingolipids play a key role in the pro-apoptotic effect of cannabinoids in MM cells. Remarkably, blockage of the CB2 receptor also inhibited cannabinoid-induced apoptosis. Cannabinoid derivative WIN-55 enhanced the anti-myeloma activity of dexamethasone and melphalan overcoming resistance to melphalan in vitro. Finally, administration of cannabinoid WIN-55 to plasmacytoma-bearing mice significantly suppressed tumor growth in vivo. Together, our data suggest that cannabinoids may be considered as potential therapeutic agents in the treatment of MM. © 2016 UICC.

  7. Potent in vivo anti-malarial activity and representative snapshot pharmacokinetic evaluation of artemisinin-quinoline hybrids

    PubMed Central

    2013-01-01

    Background Because Plasmodium falciparum displays increase tolerance against the recommended artemisinin combination therapies (ACT), new classes of anti-malarial drugs are urgently required. Previously synthesized artemisinin-aminoquinoline hybrids were evaluated to ascertain whether the potent low nanomolar in vitro anti-plasmodial activity would carry over in vivo against Plasmodium vinckei. A snapshot pharmacokinetic analysis was carried out on one of the hybrids to obtain an indication of the pharmacokinetic properties of this class of anti-malarial drugs. Methods In vitro activity of hybrids 2 and 3 were determined against the 3D7 strain of P. falciparum. Plasmodium vinckei-infected mice were treated with hybrids 1 – 3 for four days at a dosage of 0.8 mg/kg, 2.5 mg/kg, 7.5 mg/kg or 15 mg/kg intraperitoneally (ip), or orally (per os) with 2.7 mg/kg, 8.3 mg/kg, 25 mg/kg or 50 mg/kg. Artesunate was used as reference drug. A snapshot oral and IV pharmacokinetic study was performed on hybrid 2. Results Hybrids 1 – 3 displayed potent in vivo anti-malarial activity with ED50 of 1.1, 1.4 and <0.8 mg/kg by the ip route and 12, 16 and 13 mg/kg per os, respectively. Long-term monitoring of parasitaemia showed a complete cure of mice (without recrudescence) at 15 mg/kg via ip route and at 50 mg/kg by oral route for hybrid 1 and 2, whereas artesunate was only able to provide a complete cure at 30 mg/kg ip and 80 mg/kg per os. Conclusions These compounds provide a new class of desperately needed anti-malarial drug. Despite a short half-life and moderate oral bioavailability, this class of compounds was able to cure malaria in mice at very low dosages. The optimum linker length for anti-malarial activity was found to be a diaminoalkyl chain consisting of two carbon atoms either methylated or unmethylated. PMID:23433124

  8. Novel Quinazoline Derivatives Bearing Various 4-Aniline Moieties as Potent EGFR Inhibitors with Enhanced Activity Against NSCLC Cell Lines.

    PubMed

    Wang, Changyan; Sun, Yajun; Zhu, Xingqi; Wu, Bin; Wang, Qiao; Zhen, Yuhong; Shu, Xiaohong; Liu, Kexin; Zhou, Youwen; Ma, Xiaodong

    2016-04-01

    A class of novel quinazoline derivatives bearing various C-4 aniline moieties was synthesized and biologically evaluated as potent epidermal growth factor receptor (EGFR) inhibitors for intervention of non-small-cell lung cancer (NSCLC). Most of these inhibitors are comparable to gefitinib in inhibiting these cancer cell lines, and several of them even displayed superior inhibitory activity. In particular, analogue 5b with an IC50 of 0.10 μm against the EGFR wild-type A431 cells and 5c with an IC50 of 0.001 μm against the gefitinib-sensitive HCC827 cells (EGFR del E746-A750) was identified as highly active EGFR inhibitors. It was also significant that the discovered analogue 2f, not only has high potency against the gefitinib-sensitive cells (IC50 = 0.031 μm), but also possesses remarkably improved activity against the gefitinib-resistant cells. In addition, the enzymatic assays and the Western blot analysis for evaluating the effects of the typical inhibitors indicated that these molecules strongly interfere with the EGFR target.

  9. Grape seed extract regulates androgen receptor-mediated transcription in prostate cancer cells through potent anti-histone acetyltransferase activity.

    PubMed

    Park, Si Yong; Lee, Yoo-Hyun; Choi, Kyung-Chul; Seong, Ah-Reum; Choi, Hyo-Kyoung; Lee, Ok-Hee; Hwang, Han-Joon; Yoon, Ho-Geun

    2011-01-01

    Histone acetylation, which is regulated by histone acetyltransferases (HATs) and deacetylases, is an epigenetic mechanism that influences eukaryotic transcription. Significant changes in histone acetylation are associated with cancer; therefore, manipulating the acetylation status of key gene targets is likely crucial for effective cancer therapy. Grape seed extract (GSE) has a known protective effect against prostate cancer. Here, we showed that GSE significantly inhibited HAT activity by 30-80% in vitro (P < .05). Furthermore, we demonstrated significant repression of androgen receptor (AR)-mediated transcription by GSE in prostate cancer cells by measuring luciferase activity using a pGL3-PSA construct bearing the AR element in the human prostate cancer cell line LNCaP (P < .05). GSE treatment also decreased the mRNA level of the AR-regulated genes PSA and NKX 3.1. Finally, GSE inhibited growth of LNCaP cells. These results indicate that GSE potently inhibits HAT, leading to decreased AR-mediated transcription and cancer cell growth, and implicate GSE as a novel candidate for therapeutic activity against prostate cancer.

  10. Potent in vitro and in vivo antifungal activity of a small molecule host defense peptide mimic through a membrane-active mechanism.

    PubMed

    Menzel, Lorenzo P; Chowdhury, Hossain Mobaswar; Masso-Silva, Jorge Adrian; Ruddick, William; Falkovsky, Klaudia; Vorona, Rafael; Malsbary, Andrew; Cherabuddi, Kartikeya; Ryan, Lisa K; DiFranco, Kristina M; Brice, David C; Costanzo, Michael J; Weaver, Damian; Freeman, Katie B; Scott, Richard W; Diamond, Gill

    2017-06-28

    Lethal systemic fungal infections of Candida species are increasingly common, especially in immune compromised patients. By in vitro screening of small molecule mimics of naturally occurring host defense peptides (HDP), we have identified several active antifungal molecules, which also exhibited potent activity in two mouse models of oral candidiasis. Here we show that one such compound, C4, exhibits a mechanism of action that is similar to the parent HDP upon which it was designed. Specifically, its initial interaction with the anionic microbial membrane is electrostatic, as its fungicidal activity is inhibited by cations. We observed rapid membrane permeabilization to propidium iodide and ATP efflux in response to C4. Unlike the antifungal peptide histatin 5, it did not require energy-dependent transport across the membrane. Rapid membrane disruption was observed by both fluorescence and electron microscopy. The compound was highly active in vitro against numerous fluconazole-resistant clinical isolates of C. albicans and non-albicans species, and it exhibited potent, dose-dependent activity in a mouse model of invasive candidiasis, reducing kidney burden by three logs after 24 hours, and preventing mortality for up to 17 days. Together the results support the development of this class of antifungal drug to treat invasive candidiasis.

  11. Lactoferrin-derived Peptides Active towards Influenza: Identification of Three Potent Tetrapeptide Inhibitors.

    PubMed

    Scala, Maria Carmina; Sala, Marina; Pietrantoni, Agostina; Spensiero, Antonia; Di Micco, Simone; Agamennone, Mariangela; Bertamino, Alessia; Novellino, Ettore; Bifulco, Giuseppe; Gomez-Monterrey, Isabel M; Superti, Fabiana; Campiglia, Pietro

    2017-09-06

    Bovine lactoferrin is a biglobular multifunctional iron binding glycoprotein that plays an important role in innate immunity against infections. We have previously demonstrated that selected peptides from bovine lactoferrin C-lobe are able to prevent both Influenza virus hemagglutination and cell infection. To deeper investigate the ability of lactoferrin derived peptides to inhibit Influenza virus infection, in this study we identified new bovine lactoferrin C-lobe derived sequences and corresponding synthetic peptides were synthesized and assayed to check their ability to prevent viral hemagglutination and infection. We identified three tetrapeptides endowed with broad anti-Influenza activity and able to inhibit viral infection in a concentration range femto- to picomolar. Our data indicate that these peptides may constitute a non-toxic tool for potential applications as anti-Influenza therapeutics.

  12. Synthesis of Marine-Derived 3-Alkylpyridinium Alkaloids with Potent Antiprotozoal Activity

    PubMed Central

    2011-01-01

    Given the pressing need for new antiprotozoal drugs without cross-resistance with current (failing) chemotherapy, we have explored 3-tridecylpyridinium alkaloids (3TPAs), derivatives of viscosamine, as antiparasitic agents. We have developed a simple synthetic route toward viscosamine and related cyclic and linear monomers and oligomers. Evaluation for cytotoxicity on the protozoan parasites Trypanosoma brucei, Leishmania spp., and Plasmodium falciparum revealed several 3TPAs with antiprotozoal activity in the nanomolar range. Their promising selectivity index in vitro prompted us to study the dynamics of cytotoxicity on trypanosomes in more detail. Parasites were killed relatively slowly at therapeutically safe concentrations, in a process that did not target the cell cycle. Clearance of T. brucei cultures was observed at drug concentrations of 1–10 μM. PMID:24900279

  13. Highly Selective and Potent Thiophenes as PI3K Inhibitors with Oral Antitumor Activity.

    PubMed

    Liu, Kevin K-C; Zhu, JinJiang; Smith, Graham L; Yin, Min-Jean; Bailey, Simon; Chen, Jeffrey H; Hu, Qiyue; Huang, Qinhua; Li, Chunze; Li, Qing J; Marx, Matthew A; Paderes, Genevieve; Richardson, Paul F; Sach, Neal W; Walls, Marlena; Wells, Peter A; Baxi, Sangita; Zou, Aihua

    2011-11-10

    Highly selective PI3K inhibitors with subnanomolar PI3Kα potency and greater than 7000-fold selectivity against mTOR kinase were discovered through structure-based drug design (SBDD). These tetra-substituted thiophenes were also demonstrated to have good in vitro cellular potency and good in vivo oral antitumor activity in a mouse PI3K driven NCI-H1975 xenograft tumor model. Compounds with the desired human PK predictions and good in vitro ADMET properties were also identified. In this communication, we describe the rationale behind the installation of a critical triazole moiety to maintain the intricate H-bonding network within the PI3K receptor leading to both better potency and selectivity. Furthermore, optimization of the C-4 phenyl group was exploited to maximize the compounds mTOR selectivity.

  14. Design, Synthesis, and Structure–Activity Relationships of Highly Potent 5-HT3 Receptor Ligands

    PubMed Central

    2012-01-01

    The 5-HT3 receptor, a pentameric ligand-gated ion channel (pLGIC), is an important therapeutic target. During a recent fragment screen, 6-chloro-N-methyl-2-(4-methyl-1,4-diazepan-1-yl)quinazolin-4-amine (1) was identified as a 5-HT3R hit fragment. Here we describe the synthesis and structure–activity relationships (SAR) of a series of (iso)quinoline and quinazoline compounds that were synthesized and screened for 5-HT3R affinity using a [3H]granisetron displacement assay. These studies resulted in the discovery of several high affinity ligands of which compound 22 showed the highest affinity (pKi > 10) for the 5-HT3 receptor. The observed SAR is in agreement with established pharmacophore models for 5-HT3 ligands and is used for ligand–receptor binding mode prediction using homology modeling and in silico docking approaches. PMID:23006041

  15. Potent antimicrobial activity of bone cement encapsulating silver nanoparticles capped with oleic acid.

    PubMed

    Prokopovich, Polina; Köbrick, Mathias; Brousseau, Emmanuel; Perni, Stefano

    2015-02-01

    Bone cement is widely used in surgical treatments for the fixation for orthopaedic devices. Subsequently, 2-3% of patients undergoing these procedures develop infections that are both a major health risk for patients and a cost for the health service providers; this is also aggravated by the fact that antibiotics are losing efficacy because of the rising resistance of microorganisms to these substances. In this study, oleic acid capped silver nanoparticles (NP) were encapsulated into Poly(methyl methacrylate) (PMMA)-based bone cement samples at various ratios. Antimicrobial activity against Methicillin Resistant Staphylococcus aureus, S. aureus, Staphylococcus epidermidis, Acinetobacter baumannii was exhibited at NP concentrations as low as 0.05% (w/w). Furthermore, the mechanical properties and cytotoxicity of the bone cement containing these NP were assessed to guarantee that such material is safe to be used in orthopaedic surgical practice.

  16. Potent anti-inflammatory activity of novel microtubule-modulating brominated noscapine analogs.

    PubMed

    Zughaier, Susu; Karna, Prasanthi; Stephens, David; Aneja, Ritu

    2010-02-11

    Noscapine, a plant-derived, non-toxic, over-the-counter antitussive alkaloid has tubulin-binding properties. Based upon the structural resemblance of noscapine to colchicine, a tubulin-binding anti-inflammatory drug, noscapine and its semi-synthetic brominated analogs were examined for in vitro anti-inflammatory activity. Brominated noscapine analogs were found to inhibit cytokine and chemokine release from macrophage cell lines but did not affect cell viability. Brominated noscapine analogs demonstrated anti-inflammatory properties in both TLR- and non-TLR induced in vitro innate immune pathway inflammation models, mimicking septic and sterile infection respectively. In addition, electron microscopy and immunoblotting data indicated that these analogs induced robust autophagy in human macrophages. This study is the first report to identify brominated noscapines as innate immune pathway anti-inflammatory molecules.

  17. BET protein proteolysis targeting chimera (PROTAC) exerts potent lethal activity against mantle cell lymphoma cells.

    PubMed

    Sun, B; Fiskus, W; Qian, Y; Rajapakshe, K; Raina, K; Coleman, K G; Crew, A P; Shen, A; Saenz, D T; Mill, C P; Nowak, A J; Jain, N; Zhang, L; Wang, M; Khoury, J D; Coarfa, C; Crews, C M; Bhalla, K N

    2017-06-30

    Bromodomain extraterminal protein (BETP) inhibitors transcriptionally repress oncoproteins and nuclear factor-κB (NF-κB) target genes that undermines the growth and survival of mantle cell lymphoma (MCL) cells. However, BET bromodomain inhibitor (BETi) treatment causes accumulation of BETPs, associated with reversible binding and incomplete inhibition of BRD4 that potentially compromises the activity of BETi in MCL cells. Unlike BETi, BET-PROTACs (proteolysis-targeting chimera) ARV-825 and ARV-771 (Arvinas, Inc.) recruit and utilize an E3-ubiquitin ligase to effectively degrade BETPs in MCL cells. BET-PROTACs induce more apoptosis than BETi of MCL cells, including those resistant to ibrutinib. BET-PROTAC treatment induced more perturbations in the mRNA and protein expressions than BETi, with depletion of c-Myc, CDK4, cyclin D1 and the NF-κB transcriptional targets Bcl-xL, XIAP and BTK, while inducing the levels of HEXIM1, NOXA and CDKN1A/p21. Treatment with ARV-771, which possesses superior pharmacological properties compared with ARV-825, inhibited the in vivo growth and induced greater survival improvement than the BETi OTX015 of immune-depleted mice engrafted with MCL cells. Cotreatment of ARV-771 with ibrutinib or the BCL2 antagonist venetoclax or CDK4/6 inhibitor palbociclib synergistically induced apoptosis of MCL cells. These studies highlight promising and superior preclinical activity of BET-PROTAC than BETi, requiring further in vivo evaluation of BET-PROTAC as a therapy for ibrutinib-sensitive or -resistant MCL.Leukemia advance online publication, 28 July 2017; doi:10.1038/leu.2017.207.

  18. Characterization of keratin microparticles from feather biomass with potent antioxidant and anticancer activities.

    PubMed

    Sharma, Swati; Gupta, Arun; Chik, Syed Mohd S T; Kee, Chua Geek; Mistry, Bhupendra M; Kim, Doo H; Sharma, Gaurav

    2017-11-01

    In the present study chicken feathers were hydrolyzed by chemical treatment in alkaline conditions. The pH value of feather hydrolyzed solution was amended accordingly the iso-electric precipitation. Two types of keratin microparticles KM1, KM2 were synthesized under acidic conditions at 3.5 and 5.5pH respectively. The synthesized keratin microparticles possessed uniform and round surface by scanning electron microscopy (SEM). The thermal degradation of microparticles were examined by thermogravimetry (TGA). Fourier transform infrared spectroscopy (FTIR) revealed that the extracted keratin retained the most of protein backbone. The microparticles were screened for their in vitro anticancer activities by SRB bioassay towards HeLa, SK-OV-3 and A549 cancer cell lines. Futhermore, their cytotoxicity towards healthy cell lines was analyzed having Malin Darby canine kidney (MDCK) cell lines along with in vitro antioxidant activity using DPPH and ABTS methods KM1 and KM2 showed 200.31±1.01 and 139.73±0.94, 214.16±0.29 and 153.92±0.61, 328.92±3.46 and 200.33±2.48μg/mL of IC50 levels against HeLa, SK-OV-3, and A549 cell lines, respectively. Moreover, KM1 and KM2 demonstrated significant antioxidant potency with IC50 levels 13.15 and 9.02μg/mL as well as 8.96 and 5.60μg/mL in DPPH and ABTS radical scavenging bioassay, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Bacillus thuringiensis-derived Cry5B Has Potent Anthelmintic Activity against Ascaris suum

    PubMed Central

    Miller, Melanie M.; Scheib, Ulrike; Yiu, Ying Y.; Aroian, Raffi V.

    2013-01-01

    Ascaris suum and Ascaris lumbricoides are two closely related geo-helminth parasites that ubiquitously infect pigs and humans, respectively. Ascaris suum infection in pigs is considered a good model for A. lumbricoides infection in humans because of a similar biology and tissue migration to the intestines. Ascaris lumbricoides infections in children are associated with malnutrition, growth and cognitive stunting, immune defects, and, in extreme cases, life-threatening blockage of the digestive tract and aberrant migration into the bile duct and peritoneum. Similar effects can be seen with A. suum infections in pigs related to poor feed efficiency and performance. New strategies to control Ascaris infections are needed largely due to reduced treatment efficacies of current anthelmintics in the field, the threat of resistance development, and the general lack of new drug development for intestinal soil-transmitted helminths for humans and animals. Here we demonstrate for the first time that A. suum expresses the receptors for Bacillus thuringiensis crystal protein and novel anthelmintic Cry5B, which has been previously shown to intoxicate hookworms and which belongs to a class of proteins considered non-toxic to vertebrates. Cry5B is able to intoxicate A. suum larvae and adults and triggers the activation of the p38 mitogen-activated protein kinase pathway similar to that observed with other nematodes. Most importantly, two moderate doses of 20 mg/kg body weight (143 nM/kg) of Cry5B resulted in a near complete cure of intestinal A. suum infections in pigs. Taken together, these results demonstrate the excellent potential of Cry5B to treat Ascaris infections in pigs and in humans and for Cry5B to work effectively in the human gastrointestinal tract. PMID:23818995

  20. Bacillus thuringiensis-derived Cry5B has potent anthelmintic activity against Ascaris suum.

    PubMed

    Urban, Joseph F; Hu, Yan; Miller, Melanie M; Scheib, Ulrike; Yiu, Ying Y; Aroian, Raffi V

    2013-01-01

    Ascaris suum and Ascaris lumbricoides are two closely related geo-helminth parasites that ubiquitously infect pigs and humans, respectively. Ascaris suum infection in pigs is considered a good model for A. lumbricoides infection in humans because of a similar biology and tissue migration to the intestines. Ascaris lumbricoides infections in children are associated with malnutrition, growth and cognitive stunting, immune defects, and, in extreme cases, life-threatening blockage of the digestive tract and aberrant migration into the bile duct and peritoneum. Similar effects can be seen with A. suum infections in pigs related to poor feed efficiency and performance. New strategies to control Ascaris infections are needed largely due to reduced treatment efficacies of current anthelmintics in the field, the threat of resistance development, and the general lack of new drug development for intestinal soil-transmitted helminths for humans and animals. Here we demonstrate for the first time that A. suum expresses the receptors for Bacillus thuringiensis crystal protein and novel anthelmintic Cry5B, which has been previously shown to intoxicate hookworms and which belongs to a class of proteins considered non-toxic to vertebrates. Cry5B is able to intoxicate A. suum larvae and adults and triggers the activation of the p38 mitogen-activated protein kinase pathway similar to that observed with other nematodes. Most importantly, two moderate doses of 20 mg/kg body weight (143 nM/kg) of Cry5B resulted in a near complete cure of intestinal A. suum infections in pigs. Taken together, these results demonstrate the excellent potential of Cry5B to treat Ascaris infections in pigs and in humans and for Cry5B to work effectively in the human gastrointestinal tract.

  1. Inorganic polyphosphate is a potent activator of the mitochondrial permeability transition pore in cardiac myocytes

    PubMed Central

    Seidlmayer, Lea K.; Gomez-Garcia, Maria R.; Blatter, Lothar A.; Pavlov, Evgeny

    2012-01-01

    Mitochondrial dysfunction caused by excessive Ca2+ accumulation is a major contributor to cardiac cell and tissue damage during myocardial infarction and ischemia–reperfusion injury (IRI). At the molecular level, mitochondrial dysfunction is induced by Ca2+-dependent opening of the mitochondrial permeability transition pore (mPTP) in the inner mitochondrial membrane, which leads to the dissipation of mitochondrial membrane potential (ΔΨm), disruption of adenosine triphosphate production, and ultimately cell death. Although the role of Ca2+ for induction of mPTP opening is established, the exact molecular mechanism of this process is not understood. The aim of the present study was to test the hypothesis that the adverse effect of mitochondrial Ca2+ accumulation is mediated by its interaction with inorganic polyphosphate (polyP), a polymer of orthophosphates linked by phosphoanhydride bonds. We found that cardiac mitochondria contained significant amounts (280 ± 60 pmol/mg of protein) of short-chain polyP with an average length of 25 orthophosphates. To test the role of polyP for mPTP activity, we investigated kinetics of Ca2+ uptake and release, ΔΨm and Ca2+-induced mPTP opening in polyP-depleted mitochondria. polyP depletion was achieved by mitochondria-targeted expression of a polyP-hydrolyzing enzyme. Depletion of polyP in mitochondria of rabbit ventricular myocytes led to significant inhibition of mPTP opening without affecting mitochondrial Ca2+ concentration by itself. This effect was observed when mitochondrial Ca2+ uptake was stimulated by increasing cytosolic [Ca2+] in permeabilized myocytes mimicking mitochondrial Ca2+ overload observed during IRI. Our findings suggest that inorganic polyP is a previously unrecognized major activator of mPTP. We propose that the adverse effect of polyphosphate might be caused by its ability to form stable complexes with Ca2+ and directly contribute to inner mitochondrial membrane permeabilization. PMID:22547663

  2. Inorganic polyphosphate is a potent activator of the mitochondrial permeability transition pore in cardiac myocytes.

    PubMed

    Seidlmayer, Lea K; Gomez-Garcia, Maria R; Blatter, Lothar A; Pavlov, Evgeny; Dedkova, Elena N

    2012-05-01

    Mitochondrial dysfunction caused by excessive Ca2+ accumulation is a major contributor to cardiac cell and tissue damage during myocardial infarction and ischemia-reperfusion injury (IRI). At the molecular level, mitochondrial dysfunction is induced by Ca2+-dependent opening of the mitochondrial permeability transition pore (mPTP) in the inner mitochondrial membrane, which leads to the dissipation of mitochondrial membrane potential (ΔΨm), disruption of adenosine triphosphate production, and ultimately cell death. Although the role of Ca2+ for induction of mPTP opening is established, the exact molecular mechanism of this process is not understood. The aim of the present study was to test the hypothesis that the adverse effect of mitochondrial Ca2+ accumulation is mediated by its interaction with inorganic polyphosphate (polyP), a polymer of orthophosphates linked by phosphoanhydride bonds. We found that cardiac mitochondria contained significant amounts (280±60 pmol/mg of protein) of short-chain polyP with an average length of 25 orthophosphates. To test the role of polyP for mPTP activity, we investigated kinetics of Ca2+ uptake and release, ΔΨm and Ca2+-induced mPTP opening in polyP-depleted mitochondria. polyP depletion was achieved by mitochondria-targeted expression of a polyP-hydrolyzing enzyme. Depletion of polyP in mitochondria of rabbit ventricular myocytes led to significant inhibition of mPTP opening without affecting mitochondrial Ca2+ concentration by itself. This effect was observed when mitochondrial Ca2+ uptake was stimulated by increasing cytosolic [Ca2+] in permeabilized myocytes mimicking mitochondrial Ca2+ overload observed during IRI. Our findings suggest that inorganic polyP is a previously unrecognized major activator of mPTP. We propose that the adverse effect of polyphosphate might be caused by its ability to form stable complexes with Ca2+ and directly contribute to inner mitochondrial membrane permeabilization.

  3. Anti-HIV-1 activity of elafin is more potent than its precursor's, trappin-2, in genital epithelial cells.

    PubMed

    Drannik, Anna G; Nag, Kakon; Yao, Xiao-Dan; Henrick, Bethany M; Jain, Sumiti; Ball, T Blake; Plummer, Francis A; Wachihi, Charles; Kimani, Joshua; Rosenthal, Kenneth L

    2012-04-01

    Cervicovaginal lavage fluid (CVL) is a natural source of anti-HIV-1 factors; however, molecular characterization of the anti-HIV-1 activity of CVL remains elusive. In this study, we confirmed that CVLs from HIV-1-resistant (HIV-R) compared to HIV-1-susceptible (HIV-S) commercial sex workers (CSWs) contain significantly larger amounts of serine antiprotease trappin-2 (Tr) and its processed form, elafin (E). We assessed anti-HIV-1 activity of CVLs of CSWs and recombinant E and Tr on genital epithelial cells (ECs) that possess (TZM-bl) or lack (HEC-1A) canonical HIV-1 receptors. Our results showed that immunodepletion of 30% of Tr/E from CVL accounted for up to 60% of total anti-HIV-1 activity of CVL. Knockdown of endogenous Tr/E in HEC-1A cells resulted in significantly increased shedding of infectious R5 and X4 HIV-1. Pretreatment of R5, but not X4 HIV-1, with either Tr or E led to inhibition of HIV-1 infection of TZM-bl cells. Interestingly, when either HIV-1 or cells lacking canonical HIV-1 receptors were pretreated with Tr or E, HIV-1 attachment and transcytosis were significantly reduced, and decreased attachment was not associated with altered expression of syndecan-1 or CXCR4. Determination of 50% inhibitory concentrations (IC(50)) of Tr and E anti-HIV-1 activity indicated that E is ∼130 times more potent than its precursor, Tr, despite their equipotent antiprotease activities. This study provides the first experimental evidence that (i) Tr and E are among the principal anti-HIV-1 molecules of CVL; (ii) Tr and E affect cell attachment and transcytosis of HIV-1; (iii) E is more efficient than Tr regarding anti-HIV-1 activity; and (iv) the anti-HIV-1 effect of Tr and E is contextual.

  4. Synthesis and SAR of 1-acetanilide-4-aminopyrazole-substituted quinazolines: selective inhibitors of Aurora B kinase with potent anti-tumor activity.

    PubMed

    Foote, Kevin M; Mortlock, Andrew A; Heron, Nicola M; Jung, Frédéric H; Hill, George B; Pasquet, Georges; Brady, Madeleine C; Green, Stephen; Heaton, Simon P; Kearney, Sarah; Keen, Nicholas J; Odedra, Rajesh; Wedge, Stephen R; Wilkinson, Robert W

    2008-03-15

    A new class of 1-acetanilide-4-aminopyrazole-substituted quinazoline Aurora kinase inhibitors has been discovered possessing highly potent cellular activity. Continuous infusion into athymic mice bearing SW620 tumors of the soluble phosphate derivative 2 led to dose-proportional exposure of the des-phosphate compound 8 with a high-unbound fraction. The combination of potent cell activity and high free-drug exposure led to pharmacodynamic changes in the tumor at low doses, indicative of Aurora B-kinase inhibition and a reduction in tumor volume.

  5. Novel spirohydantoin derivative as a potent multireceptor-active antipsychotic and antidepressant agent.

    PubMed

    Czopek, Anna; Kołaczkowski, Marcin; Bucki, Adam; Byrtus, Hanna; Pawłowski, Maciej; Kazek, Grzegorz; Bojarski, Andrzej J; Piaskowska, Agata; Kalinowska-Tłuścik, Justyna; Partyka, Anna; Wesołowska, Anna

    2015-07-01

    A series of novel spirohydantoin derivatives with arylpiperazinylbutyl moiety were synthesized and evaluated for serotonin 5-HT1A, 5-HT2A, 5-HT7 and dopamine D2 receptors. Based on these data, four compounds were selected for further binding affinity assays on dopamine D1, D3, D4, and 5-HT2C, 5-HT6 as well as adrenergic α1 and α2C receptors, which are involved in various CNS diseases such as schizophrenia, anxiety and/or depression. The compound 14, 1-{4-[4-(2-metoxyphe-nyl)piperazin-1-yl]butyl}-3',4'-dihydro-2H,2'H,5H-spiro[imidazolidine-4,1'-naphthalene]-2,5-dione, with the most promising functional profile, mixed 5-HT2A/D2 antagonist and 5-HT1A partial agonist, was selected. In the mouse d-amphetamine-induced locomotor hyperactivity model, compound 14 produced antipsychotic-like activity, which is devoid of cataleptogenic effects and in the forced swim test in mice, it showed a significant antidepressant-like effect unlike the reference drug aripiprazole.

  6. Recombinant Saccharomyces cerevisiae (yeast-CEA) as a potent activator of murine dendritic cells.

    PubMed

    Bernstein, Michael B; Chakraborty, Mala; Wansley, Elizabeth K; Guo, Zhimin; Franzusoff, Alex; Mostböck, Sven; Sabzevari, Helen; Schlom, Jeffrey; Hodge, James W

    2008-01-24

    Recombinant Saccharomyces cerevisiae (yeast) represents a unique and attractive vehicle to deliver antigens in vaccine immunotherapy protocols for cancer or infectious disease, in that it has been shown to be extremely safe and can be administered multiple times to hosts. In the studies reported here, we describe the effects of treatment with recombinant yeast on murine immature dendritic cells (DCs). Yeast expressing human carcinoembryonic antigen (CEA) as a model antigen was studied. Injection of mice subcutaneously with yeast-CEA resulted in rapid increases in MHC class II(+) cells and total antigen-presenting cells in draining lymph nodes. Post-treatment with yeast-CEA, DCs rapidly elevated both MHC class I and class II, numerous costimulatory molecules and other DC maturation markers, and secreted a range of Type I inflammatory cytokines. Gene expression arrays also revealed the rapid up-regulation of numerous cytokine and chemokine mRNAs, as well as genes involved in signal transduction and antigen uptake. Functional studies demonstrated enhanced allospecific reactivity of DCs following treatment with yeast-CEA or control yeast. Additionally, treatment of DCs with yeast-CEA resulted in specific activation of CEA-specific CD8(+) T cells in an MHC-restricted manner in vitro. Lastly, vaccination of CEA-transgenic mice with yeast-CEA elicited antigen-specific CD4(+) and CD8(+) immune responses in vivo. Thus, these studies taken together form a scientific rationale for the use of recombinant yeast in vaccination protocols for cancer or infectious diseases.

  7. Lactoferrin is a potent regulator of bone cell activity and increases bone formation in vivo.

    PubMed

    Cornish, Jillian; Callon, Karen E; Naot, Dorit; Palmano, Kate P; Banovic, Tatjana; Bava, Usha; Watson, Maureen; Lin, Jian-Ming; Tong, P C; Chen, Qi; Chan, Vincent A; Reid, Helen E; Fazzalari, Nick; Baker, Heather M; Baker, Edward N; Haggarty, Neill W; Grey, Andrew B; Reid, Ian R

    2004-09-01

    Lactoferrin is an iron-binding glycoprotein present in epithelial secretions, such as milk, and in the secondary granules of neutrophils. We found it to be present in fractions of milk protein that stimulated osteoblast growth, so we assessed its effects on bone cell function. Lactoferrin produced large, dose-related increases in thymidine incorporation in primary or cell line cultures of human or rat osteoblast-like cells, at physiological concentrations (1-100 microg/ml). Maximal stimulation was 5-fold above control. Lactoferrin also increased osteoblast differentiation and reduced osteoblast apoptosis by up to 50-70%. Similarly, lactoferrin stimulated proliferation of primary chondrocytes. Purified, recombinant, human, or bovine lactoferrins had similar potencies. In mouse bone marrow cultures, osteoclastogenesis was dose-dependently decreased and was completely arrested by lactoferrin, 100 microg/ml, associated with decreased expression of receptor activator of nuclear factor-kappaB ligand. In contrast, lactoferrin had no effect on bone resorption by isolated mature osteoclasts. Lactoferrin was administered over calvariae of adult mice for 5 d. New bone formation, assessed using fluorochrome labels, was increased 4-fold by a 4-mg dose of lactoferrin. Thus, lactoferrin has powerful anabolic, differentiating, and antiapoptotic effects on osteoblasts and inhibits osteoclastogenesis. Lactoferrin is a potential therapeutic target in bone disorders such as osteoporosis and is possibly an important physiological regulator of bone growth.

  8. Synthesis, Structural Characterization, and Cytotoxic Activity of Novel Paramagnetic Platinum Hematoporphyrin IX Complexes: Potent Antitumor Agents

    PubMed Central

    Gencheva, G.; Tsekova, D.; Gochev, G.; Momekov, G.; Tyuliev, G.; Skumryev, V.; Karaivanova, M.; Bontchev, P. R.

    2007-01-01

    Three novel stable Pt(III) complexes with distorted octahedral structure and (dz2)1 ground state have been obtained in the course of Pt(II)-hematoporphyrin IX ((7,12-bis(1-hydroxyethyl)-3,8,13,17-tetramethyl-21H-23H-porphyn-2,18-dipropionic acid), Hp) interaction in alkaline aqueous medium and aerobic conditions. A redox interaction also takes place together with the complexation process leading to the formation of Pt(III) species and organic radicals. The processes in the reaction system and the structure of the complexes formed cis-[Pt(III)(NH3)2(Hp−3H)(H2O)2]⋅H2O 1, [Pt(III)(Hp−3H)(H2O)2]⋅H2O 2, and [Pt((O,O)Hp−2H)Cl(H2O)3] 3, were studied by UV-Vis, IR, EPR and XPS spectra, thermal (TGS, DSC), potentiometric and magnetic methods. The newly synthesized complexes show promising cytotoxic activity comparable with that of cis-platin in in vitro tests against a panel of human leukemia cell lines. The observed cytotoxicity of the complex 2 against SKW-3 cells (KE-37 derivative) is due to induction of cell death through apoptosis. PMID:18309370

  9. Multifunctional oligomer incorporation: a potent strategy to enhance the transfection activity of poly(l-lysine).

    PubMed

    Liu, Shuai; Yang, Jixiang; Ren, Hongqi; O'Keeffe-Ahern, Jonathan; Zhou, Dezhong; Zhou, Hao; Chen, Jiatong; Guo, Tianying

    2016-03-01

    Natural polycations, such as poly(l-lysine) (PLL) and chitosan (CS), have inherent superiority as non-viral vectors due to their unparalleled biocompatibility and biodegradability. However, the application was constrained by poor transfection efficiency and safety concerns. Since previous modification strategies greatly weakened the inherent advantages of natural polycations, developing a strategy for functional group introduction with broad applicability to enhance the transfection efficiency of natural polycations without compromising their cationic properties is imperative. Herein, two uncharged functional diblock oligomers P(DMAEL-b-NIPAM) and P(DMAEL-b-Vlm) were prepared from a lactose derivative, N-iso-propyl acrylamide (NIPAM) as well as 1-vinylimidazole (Vlm) and further functionalized with four small ligands folate, glutathione, cysteine and arginine, respectively, aiming to enhance the interactions of complexes with cells, which were quantified utilizing a quartz crystal microbalance (QCM) biosensor, circumventing the tedious material screening process of cell transfection. Upon incorporation with PLL and DNA, the multifunctional oligomers endow the formulated ternary complexes with great properties suitable for transfection, such as anti-aggregation in serum, destabilized endosome membrane, numerous functional sites for promoted endocytosis and therefore robust transfection activity. Furthermore, different from the conventional strategy of decreasing cytotoxicity by reducing the charge density, the multifunctional oligomer incorporation strategy maintains the highly positive charge density, which is essential for efficient cellular uptake. This system develops a new platform to modify natural polycations towards clinical gene therapy.

  10. Design and synthesis of chalcone derivatives as potent tyrosinase inhibitors and their structural activity relationship

    NASA Astrophysics Data System (ADS)

    Akhtar, Muhammad Nadeem; Sakeh, Nurshafika M.; Zareen, Seema; Gul, Sana; Lo, Kong Mun; Ul-Haq, Zaheer; Shah, Syed Adnan Ali; Ahmad, Syahida

    2015-04-01

    Browning of fruits and vegetables is a serious issue in the food industry, as it damages the organoleptic properties of the final products. Overproduction of melanin causes aesthetic problems such as melisma, freckles and lentigo. In this study, a series of chalcones (1-10) have been synthesized and examined for their tryrosinase inhibitory activity. The results showed that flavokawain B (1), flavokawain A (2) and compound 3 were found to be potential tyrosinase inhibitors, indicating IC50 14.20-14.38 μM values. This demonstrates that 4-substituted phenolic compound especially at ring A exhibited significant tyrosinase inhibition. Additionally, molecular docking results showed a strong binding affinity for compounds 1-3 through chelation between copper metal and ligands. The detailed molecular docking and SARs studies correlate well with the tyrosinase inhibition studies in vitro. The structures of these compounds were elucidated by the 1D and 2D NMR spectroscopy, mass spectrometry and single X-ray crystallographic techniques. These findings could lead to design and discover of new tyrosinase inhibitors to control the melanine overproduction and overcome the economic loss of food industry.

  11. The cyanobacterial lectin scytovirin displays potent in vitro and in vivo activity against Zaire Ebola virus.

    PubMed

    Garrison, Aura R; Giomarelli, Barbara G; Lear-Rooney, Calli M; Saucedo, Carrie J; Yellayi, Srikanth; Krumpe, Lauren R H; Rose, Maura; Paragas, Jason; Bray, Mike; Olinger, Gene G; McMahon, James B; Huggins, John; O'Keefe, Barry R

    2014-12-01

    The cyanobacterial lectin scytovirin (SVN) binds with high affinity to mannose-rich oligosaccharides on the envelope glycoprotein (GP) of a number of viruses, blocking entry into target cells. In this study, we assessed the ability of SVN to bind to the envelope GP of Zaire Ebola virus (ZEBOV) and inhibit its replication. SVN interacted specifically with the protein's mucin-rich domain. In cell culture, it inhibited ZEBOV replication with a 50% virus-inhibitory concentration (EC50) of 50 nM, and was also active against the Angola strain of the related Marburg virus (MARV), with a similar EC50. Injected subcutaneously in mice, SVN reached a peak plasma level of 100 nm in 45 min, but was cleared within 4h. When ZEBOV-infected mice were given 30 mg/kg/day of SVN by subcutaneous injection every 6h, beginning the day before virus challenge, 9 of 10 animals survived the infection, while all infected, untreated mice died. When treatment was begun one hour or one day after challenge, 70-90% of mice survived. Quantitation of infectious virus and viral RNA in samples of serum, liver and spleen collected on days 2 and 5 postinfection showed a trend toward lower titers in treated than control mice, with a significant decrease in liver titers on day 2. Our findings provide further evidence of the potential of natural lectins as therapeutic agents for viral infections. Published by Elsevier B.V.

  12. Nanosomes carrying doxorubicin exhibit potent anticancer activity against human lung cancer cells

    PubMed Central

    Srivastava, Akhil; Amreddy, Narsireddy; Babu, Anish; Panneerselvam, Janani; Mehta, Meghna; Muralidharan, Ranganayaki; Chen, Allshine; Zhao, Yan Daniel; Razaq, Mohammad; Riedinger, Natascha; Kim, Hogyoung; Liu, Shaorong; Wu, Si; Abdel-Mageed, Asim B.; Munshi, Anupama; Ramesh, Rajagopal

    2016-01-01

    Successful chemotherapeutic intervention for management of lung cancer requires an efficient drug delivery system. Gold nanoparticles (GNPs) can incorporate various therapeutics; however, GNPs have limitations as drug carriers. Nano-sized cellular vesicles like exosomes (Exo) can ferry GNP-therapeutic complexes without causing any particle aggregation or immune response. In the present study, we describe the development and testing of a novel Exo-GNP-based therapeutic delivery system -‘nanosomes’- for lung cancer therapy. This system consists of GNPs conjugated to anticancer drug doxorubicin (Dox) by a pH-cleavable bond that is physically loaded onto the exosomes (Exo-GNP-Dox). The therapeutic efficacy of Dox in nanosomes was assessed in H1299 and A549 non-small cell lung cancer cells, normal MRC9 lung fibroblasts, and Dox-sensitive human coronary artery smooth muscle cells (HCASM). The enhanced rate of drug release under acidic conditions, successful uptake of the nanosomes by the recipient cells and the cell viability assays demonstrated that nanosomes exhibit preferential cytotoxicity towards cancer cells and have minimal activity on non-cancerous cells. Finally, the underlying mechanism of cytotoxicity involved ROS-mediated DNA damage. Results from this study mark the establishment of an amenable drug delivery vehicle and highlight the advantages of a natural drug carrier that demonstrates reduced cellular toxicity and efficient delivery of therapeutics to cancer cells. PMID:27941871

  13. Measles Edmonston Vaccine Strain Derivatives have Potent Oncolytic Activity against Osteosarcoma

    PubMed Central

    Musibay, Evidio Domingo; Allen, Cory; Kurokawa, Cheyne; Hardcastle, Jayson J.; Aderca, Ileana; Msaouel, Pavlos; Bansal, Aditya; Jiang, Huailei; DeGrado, Timothy R.; Galanis, Evanthia

    2015-01-01

    Osteosarcoma is the most common primary bone tumor affecting children and young adults, and development of metastatic disease is associated with poor prognosis. The purpose of this study was to evaluate the antitumor efficacy of virotherapy with engineered measles virus (MV) vaccine strains in the treatment of osteosarcoma. Cell lines derived from pediatric patients with osteosarcoma (HOS, MG63, 143B, KHOS-312H, U2-OS and SJSA1) were examined for MV-GFP and MV-NIS gene expression and cytotoxicity as defined by syncytial formation, cell death, and eradication of cell monolayers: significant antitumor activity was demonstrated. Findings were correlated with in vivo efficacy in subcutaneous, orthotopic (tibial bone), and lung metastatic osteosarcoma xenografts treated with the MV derivative MV-NIS via the intratumoral (IT) or intravenous (IV) route. Following treatment, we observed decrease in tumor growth of subcutaneous xenografts (p=0.0374) and prolongation of survival in mice with orthotopic (p<0.0001) and pulmonary metastatic osteosarcoma tumors (p=0.0207). Expression of the NIS transgene in MV-NIS infected tumors allowed for SPECT-CT and PET-CT imaging of virus infected tumors in vivo. Our data support the translational potential of MV-based virotherapy approaches in the treatment of recurrent and metastatic osteosarcoma. PMID:25394505

  14. Rhamnazin, a novel inhibitor of VEGFR2 signaling with potent antiangiogenic activity and antitumor efficacy

    SciTech Connect

    Yu, Yao; Cai, Wei; Pei, Chong-gang; Shao, Yi

    2015-03-20

    Anti-angiogenesis targeting vascular endothelial growth factor receptor 2 (VEGFR2) has emerged as an important tool for cancer therapy. The identification of new drugs from natural products has a long and successful history. In this study, we described a novel VEGFR2 inhibitor, rhamnazin, which inhibits tumor angiogenesis and growth. Rhamnazin significantly inhibited proliferation, migration and tube formation of human umbilical vascular endothelial cells (HUVECs) in vitro as well as inhibited sprouts formation of rat aorta ring. In addition, it inhibited vascular endothelial growth factor (VEGF)-induced phosphorylation of VEGFR2 and its downstream signaling regulator in HUVECs. Moreover, rhamnazin could directly inhibit proliferation of breast cancer cells MDA-MB-231 in vitro and in vivo. Oral administration of rhamnazin at a dose of 200 mg/kg/day could markedly inhibited human tumor xenograft growth and decreased microvessel densities (MVD) in tumor sections. Taken together, these preclinical evaluations suggest that rhamnazin inhibits angiogenesis and may be a promising anticancer drug candidate. - Highlights: • Rhamnazin inhibits the response of HUVECs to VEGF in vitro. • Rhamnazin inhibits VEGFR2 kinase activity and its downstream signaling. • Rhamnazin prevents the growth of MDA-MB-231 tumor and reduces micro-vessel density in vivo.

  15. Tocotrienol-Rich Fraction from Rice Bran Demonstrates Potent Radiation Protection Activity

    PubMed Central

    Krager, Kimberly J.; Pineda, E. Nathalie; Kharade, Sujay V.; Kordsmeier, Mary; Howard, Luke; Breen, Philip J.; Compadre, Cesar M.; Hauer-Jensen, Martin; Aykin-Burns, Nukhet

    2015-01-01

    The vitamin E analogs δ-tocotrienol (DT3) and γ-tocotrienol (GT3) have significant protective and mitigative capacity against the detrimental effects of ionizing radiation (IR). However, the expense of purification limits their potential use. This study examined the tocotrienol-rich fraction of rice bran (TRFRB) isolated from rice bran deodorizer distillate, a rice oil refinement waste product, to determine its protective effects against IR induced oxidative damage and H2O2. Several cell lines were treated with tocotrienols or TRFRB prior to or following exposure to H2O2 or IR. To determine the radioprotective capacity cells were analyzed for morphology, mitochondrial bioenergetics, clonogenic survival, glutathione oxidation, cell cycle, and migration rate. TRFRB displayed similar antioxidant activity compared to pure tocotrienols. Cells pretreated with TRFRB or DT3 exhibited preserved cell morphology and mitochondrial respiration when exposed to H2O2. Oxidized glutathione was decreased in TRFRB treated cells exposed to IR. TRFRB reversed mitochondrial uncoupling and protected cells migration rates following IR exposure. The protective antioxidant capacity of TRFRB treated cells against oxidative injury was similar to that of purified DT3. TRFRB effectively protects normal cells against IR induced injury suggesting that rice bran distillate may be an inexpensive and abundant alternate source. PMID:26425129

  16. Antimicrobial peptides containing unnatural amino acid exhibit potent bactericidal activity against ESKAPE pathogens.

    PubMed

    Hicks, R P; Abercrombie, J J; Wong, R K; Leung, K P

    2013-01-01

    A series of 36 synthetic antimicrobial peptides containing unnatural amino acids were screened to determine their effectiveness to treat Enterococcus faecium, Staphylococcus aureus, Klebsiella pnemoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species (ESKAPE) pathogens, which are known to commonly infect chronic wounds. The primary amino acid sequences of these peptides incorporate either three or six dipeptide units consisting of the unnatural amino acids Tetrahydroisoquinolinecarboxylic acid (Tic) and Octahydroindolecarboxylic acid (Oic). The Tic-Oic dipeptide units are separated by SPACER amino acids with specific physicochemical properties that control how these peptides interact with bacterial cell membranes of different chemical compositions. These peptides exhibited minimum inhibitory concentrations (MIC) against these pathogens in the range from >100 to 6.25 μg/mL. The observed diversity of MIC values for these peptides against the various bacterial strains are consistent with our hypothesis that the complementarity of the physicochemical properties of the peptide and the lipid of the bacteria's cell membrane determines the resulting antibacterial activity of the peptide. Published by Elsevier Ltd.

  17. Pyrrolo[2,3-h]quinolinones: a new ring system with potent photoantiproliferative activity.

    PubMed

    Barraja, Paola; Diana, Patrizia; Montalbano, Alessandra; Dattolo, Gaetano; Cirrincione, Girolamo; Viola, Giampietro; Vedaldi, Daniela; Dall'Acqua, Francesco

    2006-12-15

    A new class of compounds, the pyrrolo[2,3-h]quinolin-2-ones, nitrogen isosters of the angular furocoumarin Angelicin, was synthesized with the aim of obtaining new photochemotherapeutic agents with increased antiproliferative activity and lower undesired toxic effects than the lead compound. Two synthetic pathways were approached to allow the isolation both of the dihydroderivatives 10-17 and of the aromatic ring system 23. Compounds 10-17 showed a remarkable phototoxicity and a great UVA dose dependence reaching IC(50) values at submicromolar level. Intracellular localization of these compounds has been evaluated by means of fluorescence microscopy using tetramethylrhodamine methyl ester and acridine orange, which are specific fluorescent probes for mitochondria and lysosomes, respectively. A weak co-staining was observed with mitochondrial stain, whereas a specific localization in lysosomes was observed. Studies directed to elucidate the mode of action of this series of compounds revealed that they do not intercalate with DNA and do not induce photodamage to the macromolecule. On the contrary, they induce significative photodamage to lipids and proteins.

  18. Actinomycin D binding mode reveals the basis for its potent HIV-1 and cancer activity

    NASA Astrophysics Data System (ADS)

    Paramanathan, Thayaparan; Vladescu, Ioana D.; McCauley, Micah J.; Rouzina, Ioulia; Williams, Mark C.

    2011-03-01

    Actinomycin D (ActD) is one of the most studied antibiotics, which has been used as an anti-cancer agent and also shown to inhibit HIV reverse transcription. Initial studies with ActD established that it intercalates double stranded DNA (dsDNA). However, recent studies have shown that ActD binds with even higher affinity to single stranded DNA (ssDNA). In our studies we use optical tweezers to stretch and hold single dsDNA molecule at constant force in the presence of varying ActD concentrations until the binding reaches equilibrium. The change in dsDNA length upon ActD binding measured as a function of time yields the rate of binding in addition to the equilibrium lengthening of DNA. The results suggest extremely slow kinetics, on the order of several minutes and 0.52 +/- 0.06 μ M binding affinity. Holding DNA at constant force while stretching and relaxing suggests that ActD binds to two single strands that are close to each other rather than to pure dsDNA or ssDNA. This suggests that biological activity of ActD that contributes towards the inhibition of cellular replication is due to its ability to bind at DNA bubbles during RNA transcription, thereby stalling the transcription process.

  19. Tumor necrosis factor: a potent effector molecule for tumor cell killing by activated macrophages.

    PubMed Central

    Urban, J L; Shepard, H M; Rothstein, J L; Sugarman, B J; Schreiber, H

    1986-01-01

    Activated macrophages (aM phi) destroy more effectively cancer cells than normal cells. The mechanism by which macrophages destroy cancer cells is not known. We report here that tumor cells susceptible to aM phi were killed by recombinant (r) tumor necrosis factor type alpha (TNF-alpha), whereas variant tumor cells resistant to aM phi after selection in vitro or in vivo were resistant to killing by rTNF-alpha. The converse selection for rTNF-alpha-resistant variants resulted in cells that were also resistant to killing by aM phi. The sensitivity of macrophage-resistant variants was not changed to other tumoricidal cells or soluble mediators, except that the macrophage-resistant variants were also resistant to the effects of another cytotoxic protein, B-cell lymphotoxin, which is structurally related to rTNF-alpha. Similar results were obtained regardless of whether short-term or long-term cytotoxic effects of aM phi were measured. Finally, it was shown that killing of tumor cells by murine aM phi was completely inhibited with a polyclonal antibody that neutralizes the effects of murine TNF-alpha. These results suggest a major role for TNF-alpha in tumor cell destruction by aM phi in vitro and in vivo. PMID:3487788

  20. Potent antimicrobial activity of bone cement encapsulating silver nanoparticles capped with oleic acid

    PubMed Central

    Prokopovich, Polina; Köbrick, Mathias; Brousseau, Emmanuel; Perni, Stefano

    2015-01-01

    Bone cement is widely used in surgical treatments for the fixation for orthopaedic devices. Subsequently, 2–3% of patients undergoing these procedures develop infections that are both a major health risk for patients and a cost for the health service providers; this is also aggravated by the fact that antibiotics are losing efficacy because of the rising resistance of microorganisms to these substances. In this study, oleic acid capped silver nanoparticles (NP) were encapsulated into Poly(methyl methacrylate) (PMMA)-based bone cement samples at various ratios. Antimicrobial activity against Methicillin Resistant Staphylococcus aureus, S. aureus, Staphylococcus epidermidis, Acinetobacter baumannii was exhibited at NP concentrations as low as 0.05% (w/w). Furthermore, the mechanical properties and cytotoxicity of the bone cement containing these NP were assessed to guarantee that such material is safe to be used in orthopaedic surgical practice. © 2014 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 273–281, 2015. PMID:24819471

  1. Vaccine with beta-defensin 2-transduced leukemic cells activates innate and adaptive immunity to elicit potent antileukemia responses.

    PubMed

    Ma, Xiao-Tong; Xu, Bin; An, Li-Li; Dong, Cheng-Ya; Lin, Yong-Min; Shi, Yang; Wu, Ke-Fu

    2006-01-15

    Murine beta-defensin 2 (MBD2) is a small antimicrobial peptide of the innate immune system. Recent study showed that MBD2 could not only recruit immature dendritic cells but also activate them by Toll-like receptor 4 and thus may provide a critical link between the innate immune system and the adaptive immune response. In this report, we examined the antileukemia activity of MBD2 in a murine model of acute lymphoid leukemia (ALL) L1210. L1210 cells were engineered to secrete biologically functional MBD2. MBD2-modified L1210 (L1210-MBD2) showed significantly reduced leukemogenecity, resulting in a 80% rate of complete leukemia rejection. Inoculation of mice with L1210-MBD2 induced enhanced CTL and natural killer (NK) activity and augmented interleukin-12 and IFN-gamma production. All the recovered mice from the inoculation showed a protective immunity to the following challenge with parental L1210 cells and generate leukemia-specific memory CTL. Vaccines with irradiated L1210-MBD2 cells could cure 50% leukemia-bearing mice. Depletion of CD8+ T cells but not CD4+ T cells completely abrogated the antileukemia activity of MBD2. Interestingly, NK cells were also required for the MBD2-mediated antileukemia response, although ALL generally display a high degree of resistance to NK-mediated lysis. Our results suggest that MBD2 can activate both innate and adaptive immunity to generate potent antileukemia response, and MBD2 immunotherapy warrants further evaluation as a potential treatment for ALL.

  2. Potent α-amylase inhibitory activity of Indian Ayurvedic medicinal plants

    PubMed Central

    2011-01-01

    Background Indian medicinal plants used in the Ayurvedic traditional system to treat diabetes are a valuable source of novel anti-diabetic agents. Pancreatic α-amylase inhibitors offer an effective strategy to lower the levels of post-prandial hyperglycemia via control of starch breakdown. In this study, seventeen Indian medicinal plants with known hypoglycemic properties were subjected to sequential solvent extraction and tested for α-amylase inhibition, in order to assess and evaluate their inhibitory potential on PPA (porcine pancreatic α-amylase). Preliminary phytochemical analysis of the lead extracts was performed in order to determine the probable constituents. Methods Analysis of the 126 extracts, obtained from 17 plants (Aloe vera (L.) Burm.f., Adansonia digitata L., Allium sativum L., Casia fistula L., Catharanthus roseus (L.) G. Don., Cinnamomum verum Persl., Coccinia grandis (L.) Voigt., Linum usitatisumum L., Mangifera indica L., Morus alba L., Nerium oleander L., Ocimum tenuiflorum L., Piper nigrum L., Terminalia chebula Retz., Tinospora cordifolia (Willd.) Miers., Trigonella foenum-graceum L., Zingiber officinale Rosc.) for PPA inhibition was initially performed qualitatively by starch-iodine colour assay. The lead extracts were further quantified with respect to PPA inhibition using the chromogenic DNSA (3, 5-dinitrosalicylic acid) method. Phytochemical constituents of the extracts exhibiting≥ 50% inhibition were analysed qualitatively as well as by GC-MS (Gas chromatography-Mass spectrometry). Results Of the 126 extracts obtained from 17 plants, 17 extracts exhibited PPA inhibitory potential to varying degrees (10%-60.5%) while 4 extracts showed low inhibition (< 10%). However, strong porcine pancreatic amylase inhibitory activity (> 50%) was obtained with 3 isopropanol extracts. All these 3 extracts exhibited concentration dependent inhibition with IC50 values, viz., seeds of Linum usitatisumum (540 μgml-1), leaves of Morus alba (1440

  3. A novel small molecule agent displays potent anti-myeloma activity by inhibiting the JAK2-STAT3 signaling pathway

    PubMed Central

    Zhu, Jingyu; Xu, Yujia; Wang, Siyu; Xu, Xin; Ji, Peng; Yu, Yang; Cao, Biyin; Han, Kunkun; Hou, Tingjun; Xu, Zhuan; Kong, Yan; Jiang, Gaofeng; Tang, Xiaowen; Qiao, Chunhua; Mao, Xinliang

    2016-01-01

    The oncogenic STAT3 signaling pathway is emerging as a promising target for the treatment of multiple myeloma (MM). In the present study, we identified a novel STAT3 inhibitor SC99 in a target-based high throughput screen. SC99 inhibited JAK2-STAT3 activation but had no effects on other transcription factors such as NF-κB, and kinases such as AKT, ERK, and c-Src that are in association with STAT3 signaling pathway. Furthermore, SC99 downregulated the expression of STAT3-modulated genes, including Bcl-2, Bcl-xL, VEGF, cyclin D2, and E2F-1. By inhibiting the STAT3 signaling, SC99 induced MM cell apoptosis which could be partly abolished by the ectopic expression of STAT3. Furthermore, SC99 displayed potent anti-MM activity in two independent MM xenograft models in nude mice. Oral administration of SC99 led to marked decrease of tumor growth within 10 days at a daily dosage of 30 mg/kg, but did not raise toxic effects. Taken together, this study identified a novel oral JAK2/STAT3 inhibitor that could be developed as an anti-myeloma agent. PMID:26814430

  4. The mitochondrion interfering compound NPC-26 exerts potent anti-pancreatic cancer cell activity in vitro and in vivo.

    PubMed

    Dong, Yang-Yang; Zhuang, Yi-Huang; Cai, Wen-Jie; Liu, Yan; Zou, Wen-Bing

    2016-11-01

    The development of novel anti-pancreatic cancer agents is extremely important. Here, we investigated the anti-pancreatic cancer activity by NPC-26, a novel mitochondrion interfering compound. We showed that NPC-26 was anti-proliferative and cytotoxic to human pancreatic cancer cells, possibly via inducing caspase-9-dependent cell apoptosis. Pharmacological inhibition or shRNA-mediated silence of caspase-9 attenuated NPC-26-induced pancreatic cancer cell death and apoptosis. Further, NPC-26 treatment led to mitochondrial permeability transition pore (mPTP) opening in the cancer cells, which was evidenced by mitochondrial depolarization, ANT-1(adenine nucleotide translocator-1)-Cyp-D (cyclophilin-D) association and oxidative phosphorylation disturbance. mPTP blockers (cyclosporin and sanglifehrin A) or shRNA-mediated knockdown of key mPTP components (Cyp-D and ANT-1) dramatically attenuated NPC-26-induced pancreatic cancer cell apoptosis. Importantly, we showed that NPC-26, at a low concentration, potentiated gemcitabine-induced mPTP opening and subsequent pancreatic cancer cell apoptosis. In vivo, NPC-26 intraperitoneal injection significantly suppressed the growth of PANC-1 xenograft tumors in nude mice. Meanwhile, NPC-26 sensitized gemcitabine-mediated anti-pancreatic cancer activity in vivo. In summary, the results of this study suggest that NPC-26, alone or together with gemcitabine, potently inhibits pancreatic cancer cells possibly via disrupting mitochondrion.

  5. Epitope Mapping of M36, a Human Antibody Domain with Potent and Broad HIV-1 Inhibitory Activity

    PubMed Central

    Chen, Weizao; Yuan, Xiaohui; Chong, Huihui; Prabakaran, Ponraj; Dimitrov, Dimiter S.; He, Yuxian

    2013-01-01

    M36 is the first member of a novel class of potent HIV-1 entry inhibitors based on human engineered antibody domains (eAds). It exhibits broad inhibitory activity suggesting that its CD4-induced epitope is highly conserved. Here, we describe fine mapping of its epitope by using several approaches. First, a panel of mimotopes was affinity-selected from a random peptide library and potential m36-binding residues were computationally predicted. Second, homology modeling of m36 and molecular docking of m36 onto gp120 revealed potentially important residues in gp120-m36 interactions. Third, the predicted contact residues were verified by site-directed mutagenesis. Taken together, m36 epitope comprising three discontinuous sites including six key gp120 residues (Site C1: Thr123 and Pro124; Site C3: Glu370 and Ile371; Site C4: Met426 and Trp427) were identified. In the 3D structure of gp120, the sites C1 and C4 are located in the bridging sheet and the site C3 is within the β15-α3 excursion, which play essential roles for the receptor- and coreceptor-binding and are major targets of neutralizing antibodies. Based on these results we propose a precise localization of the m36 epitope and suggest a mechanism of its broad inhibitory activity which could help in the development of novel HIV-1 therapeutics based on eAds. PMID:23776690

  6. Epigallocatechin-3-gallate potently inhibits the in vitro activity of hydroxy-3-methyl-glutaryl-CoA reductase[S

    PubMed Central

    Cuccioloni, Massimiliano; Mozzicafreddo, Matteo; Spina, Michele; Tran, Chi Nhan; Falconi, Maurizio; Eleuteri, Anna Maria; Angeletti, Mauro

    2011-01-01

    Hydroxy-3-methyl-glutaryl-CoA reductase (HMGR) is the rate-controlling enzyme of cholesterol synthesis, and owing to its biological and pharmacological relevance, researchers have investigated several compounds capable of modulating its activity with the hope of developing new hypocholesterolemic drugs. In particular, polyphenol-rich extracts were extensively tested for their cholesterol-lowering effect as alternatives, or adjuvants, to the conventional statin therapies, but a full understanding of the mechanism of their action has yet to be reached. Our work reports on a detailed kinetic and equilibrium study on the modulation of HMGR by the most-abundant catechin in green tea, epigallocatechin-3-gallate (EGCG). Using a concerted approach involving spectrophotometric, optical biosensor, and chromatographic analyses, molecular docking, and site-directed mutagenesis on the cofactor site of HMGR, we have demonstrated that EGCG potently inhibits the in vitro activity of HMGR (Ki in the nanomolar range) by competitively binding to the cofactor site of the reductase. Finally, we evaluated the effect of combined EGCG-statin administration. PMID:21357570

  7. Potent antitumor activity of quinolone compounds with an unsaturated aminoazabicyclo group at the C-7 position of the quinolone ring.

    PubMed

    Arakawa, H; Mano, E; Hakoda, N; Yoshinari, T; Nakagawa, S; Okura, A

    1996-04-01

    Relationships between the substituents on the quinolone nucleus of 2 and related compounds and their biological activities were studied. 2, 3 and 1 carrying a (1R, 2R, 6R)-2-amino-8-azabicyclo[4.3.0.]non-3-en-8-yl group at the C-7 position increased the rate of formation of DNA-protein complexes in cells, and inhibited the growth of tumor cells more strongly than the compounds with other substituents. The introduction of a fluorine atom or a methoxy group at the 8-position and an amino group at the 5-position increased the activity still further. The three compounds listed were all effective against P388 leukemia in mice. Subcutaneous injection of 2 at 2 mg/kg strongly suppressed the growth of human MX-1 breast cancer cells in nude mice. 1 has various functional groups that increase the cytotoxic potential of quinolone derivatives: a (1R, 2R, 6R)-2-amino-8-azabicyclo[4.3.0.]non-3-en-8-yl moiety at C-7, a cyclopropyl group at the 1-position, fluorine atoms at the 6- and 8-positions, and an amino group at the 5-position of the quinoline carboxylic acid. These data suggest that this series of compounds provide good models for the further design of potent antitumor quinolones.

  8. Discovery of a Potent HIV Integrase Inhibitor That Leads to a Prodrug with Significant anti-HIV Activity

    PubMed Central

    2011-01-01

    Worldwide research efforts in drug discovery involving HIV integrase have produced only one compound, raltegravir, that has been approved for clinical use in HIV/AIDS. As resistance, toxicity, and drug–drug interactions are recurring issues with all classes of anti-HIV drugs, the discovery of novel integrase inhibitors remains a significant scientific challenge. We have designed a lead HIV-1 strand transfer (ST) inhibitor (IC50 70 nM), strategically assembled on a pyridinone scaffold. A focused structure–activity investigation of this parent compound led to a significantly more potent ST inhibitor, 2 (IC50 6 ± 3 nM). Compound 2 exhibits good stability in pooled human liver microsomes. It also displays a notably favorable profile with respect to key human cytochrome P450 (CYP) isozymes and human UDP glucuronosyl transferases (UGTs). The prodrug of inhibitor 2, i.e., compound 10, was found to possess remarkable anti-HIV-1 activity in cell culture (EC50 9 ± 4 nM, CC50 135 ± 7 μM, therapeutic index = 15 000). PMID:22328963

  9. Fatty acids from the cyanobacterium Microcystis aeruginosa with potent inhibitory effects on fish gill Na+/K+-ATPase activity.

    PubMed

    Bury, N R; Codd, G A; Wendelaaar Bonga, S E; Flik, G

    1998-01-01

    Fatty acids from two strains of the cyanobacterium Microcystis aeruginosa, PCC 7820 (a strain that produces the hepatotoxin microcystin-LR, MC-LR) and CYA 43 (a strain that produces only small quantities of MC-LR), were extracted, partially characterised and tested for their inhibitory effect on the K+-dependent p-nitrophenol phosphatase (pNPPase) activity of tilapia (Oreochromis mossambicus) gill basolateral membrane. Thin-layer chromatography of the lipids from dichloromethane:methanol extracts of M. aeruginosa PCC 7820 and CYA 43, using diethylether:isopropanol:formic acid (100:4.5:2.5) as solvent, yielded five inhibitory products from M. aeruginosa 7820 and six from M. aeruginosa CYA 43. None of these products could be related to MC-LR. The inhibitory behaviour of the products mimics that of a slow, tight-binding inhibitor. The inhibitory activity is removed by incubation of extracts with fatty-acid-free bovine serum albumin (FAF-BSA). However, FAF-BSA only partially reversed the inhibition of K+-dependent pNPPase on fish gills pre-exposed to the extracted products. We conclude that M. aeruginosa strains PCC 7820 and CYA 43 produce fatty acids with potent inhibitory effects on K+-dependent pNPPase. The release of these products following lysis of cyanobacterial blooms may help to explain fish kills through a disturbance of gill functioning.

  10. Bioactives in cactus (Opuntia ficus-indica) stems possess potent antioxidant and pro-apoptotic activities through COX-2 involvement.

    PubMed

    Kim, Jinhee; Soh, Soon Yil; Shin, Juha; Cho, Chi-Woung; Choi, Young Hee; Nam, Sang-Yong

    2015-10-01

    Bioactives extracted from cactus (Opuntia ficus-indica) stems were investigated for their chemopreventive activities using human cancer cells in vitro. The bioactives present in crude extracts were detected and quantified using high-performance liquid chromatography. Among all the extracts, such as hexane, ethyl acetate (EtOAc), acetone, methanol (MeOH), and MeOH:water (80:20), the MeOH extract had the highest amount of polyphenolic compounds and the acetone extract exhibited the most potent effect at scavenging the 2,2,-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS(•+) ) radical. In addition, most of the extracts, with the exception of hexane, exhibited significant cytotoxicity in human SW480 colon and MCF7 breast cancer cells. Overall, the SW480 cells were more sensitive than the MCF7 cells to the cytotoxic effect of the O. ficus-indica extracts (OFEs). Cell death by OFE treatment caused significant inhibition of cyclooxygenase-2 and increased the Bax/Bcl2 ratio in both SW480 and MCF7 cell lines. However, degradation of poly (ADP-ribose) polymerase was significantly increased by OFE only in the MCF7 cells, thereby inducing apoptosis. These findings demonstrate the health-benefit roles, including anti-oxidative and anti-proliferative activities as well as pro-apoptotic effects, of bioactive compounds in OFEs, suggesting a chemopreventive role in human cancer cells. © 2014 Society of Chemical Industry.

  11. Potent neutralization of VEGF biological activities with a fully human antibody Fab fragment directed against VEGF receptor 2

    SciTech Connect

    Miao, H.-Q. . E-mail: hua-quan.miao@imclone.com; Hu, Kun; Jimenez, Xenia; Navarro, Elizabeth; Zhang, Haifan; Lu Dan; Ludwig, Dale L.; Balderes, Paul; Zhu Zhenping . E-mail: zhenping.zhu@imclone.com

    2006-06-23

    Compelling evidence suggest that vascular endothelial growth factor (VEGF) and its receptors, especially receptor 2 (VEGFR2, or kinase insert domain-containing receptor, KDR), play a critical role in angiogenesis under both physiological and pathological conditions, including cancer and angiogenic retinopathies such as age-related macular degeneration (AMD). To this end, inhibition of angiogenesis with antagonists to either VEGF or KDR has yielded significant therapeutic efficacy both in preclinical studies in animal models and in clinical trials in patients with cancer and AMD. We previously reported the identification of a high affinity, fully human anti-KDR antibody fragment, 1121B Fab, through a highly stringent affinity maturation process with a Fab originally isolated from a naive human antibody phage display library. In this study, we demonstrate that 1121B Fab is able to strongly block KDR/VEGF interaction, resulting in potent inhibition of an array of biological activities of VEGF, including activation of the receptor and its signaling pathway, intracellular calcium mobilization, and migration and proliferation of endothelial cells. Taken together, our data lend strong support to the further development of 1121B Fab fragment as an anti-angiogenesis agent in both cancer and angiogenic retinopathies.

  12. Enabling the Discovery and Virtual Screening of Potent and Safe Antimicrobial Peptides. Simultaneous Prediction of Antibacterial Activity and Cytotoxicity.

    PubMed

    Kleandrova, Valeria V; Ruso, Juan M; Speck-Planche, Alejandro; Dias Soeiro Cordeiro, M Natália

    2016-08-08

    Antimicrobial peptides (AMPs) represent promising alternatives to fight against bacterial pathogens. However, cellular toxicity remains one of the main concerns in the early development of peptide-based drugs. This work introduces the first multitasking (mtk) computational model focused on performing simultaneous predictions of antibacterial activities, and cytotoxicities of peptides. The model was created from a data set containing 3592 cases, and it displayed accuracy higher than 96% for classifying/predicting peptides in both training and prediction (test) sets. The technique known as alanine scanning was computationally applied to illustrate the calculation of the quantitative contributions of the amino acids (in their respective positions of the sequence) to the biological effects of a defined peptide. A small library formed by 10 peptides was generated, where peptides were designed by considering the interpretations of the different descriptors in the mtk-computational model. All the peptides were predicted to exhibit high antibacterial activities against multiple bacterial strains, and low cytotoxicity against various cell types. The present mtk-computational model can be considered a very useful tool to support high throughput research for the discovery of potent and safe AMPs.

  13. Three-dimensional structure-activity relationship study of belactosin A and its stereo- and regioisomers: development of potent proteasome inhibitors by a stereochemical diversity-oriented strategy.

    PubMed

    Yoshida, Keisuke; Yamaguchi, Kazuya; Mizuno, Akira; Unno, Yuka; Asai, Akira; Sone, Takayuki; Yokosawa, Hideyoshi; Matsuda, Akira; Arisawa, Mitsuhiro; Shuto, Satoshi

    2009-05-07

    The development of potent proteasome inhibitors based on the stereochemical diversity-oriented strategy using a conformationally rigid cyclopropane structure was investigated. Thus, a series of stereo- and regioisomeric analogs of belactosin A (2), a cyclopropane amino acid (methanoamino acid)-containing tripeptidic proteasome inhibitor, were designed, in which the central cyclopropane amino acid part was replaced with the corresponding stereo- or regioisomer. Using a series of stereoisomeric cyclopropane amino acid equivalents with the cis/trans, D/L, and syn/anti stereochemical diversity, which were previously developed by us, as key units, the target compounds were successfully synthesized. Biological evaluation showed that, as expected, compound activity changed depending on the stereochemistry of the central cyclopropane amino acid part: the trans/L-syn-isomer 7 and the cis/L-anti-isomer 9 were more than twice as potent as natural belactosin A (trans/L-anti-isomer). Furthermore, the tripeptidic compound 13, the synthetic precursor for the unnatural cis/L-anti-isomer 9, was identified as a highly potent proteasome inhibitor. This compound, which is 20 times as potent as belactosin A and is even more potent than the well-known inhibitor lactacystin (4), may be an effective lead for developing clinically useful anticancer drugs. These results show that the stereochemical diversity-oriented approach can be a powerful strategy for the development of highly active compounds in medicinal chemical studies.

  14. Alphavirus replicon particles expressing TRP-2 provide potent therapeutic effect on melanoma through activation of humoral and cellular immunity.

    PubMed

    Avogadri, Francesca; Merghoub, Taha; Maughan, Maureen F; Hirschhorn-Cymerman, Daniel; Morris, John; Ritter, Erika; Olmsted, Robert; Houghton, Alan N; Wolchok, Jedd D

    2010-09-10

    Malignant melanoma is the deadliest form of skin cancer and is refractory to conventional chemotherapy and radiotherapy. Therefore alternative approaches to treat this disease, such as immunotherapy, are needed. Melanoma vaccine design has mainly focused on targeting CD8+ T cells. Activation of effector CD8+ T cells has been achieved in patients, but provided limited clinical benefit, due to immune-escape mechanisms established by advanced tumors. We have previously shown that alphavirus-based virus-like replicon particles (VRP) simultaneously activate strong cellular and humoral immunity against the weakly immunogenic melanoma differentiation antigen (MDA) tyrosinase. Here we further investigate the antitumor effect and the immune mechanisms of VRP encoding different MDAs. VRP encoding different MDAs were screened for their ability to prevent the growth of the B16 mouse transplantable melanoma. The immunologic mechanisms of efficacy were investigated for the most effective vaccine identified, focusing on CD8+ T cells and humoral responses. To this end, ex vivo immune assays and transgenic mice lacking specific immune effector functions were used. The studies identified a potent therapeutic VRP vaccine, encoding tyrosinase related protein 2 (TRP-2), which provided a durable anti-tumor effect. The efficacy of VRP-TRP2 relies on a novel immune mechanism of action requiring the activation of both IgG and CD8+ T cell effector responses, and depends on signaling through activating Fcγ receptors. This study identifies a VRP-based vaccine able to elicit humoral immunity against TRP-2, which plays a role in melanoma immunotherapy and synergizes with tumor-specific CD8+ T cell responses. These findings will aid in the rational design of future immunotherapy clinical trials.

  15. Alphavirus Replicon Particles Expressing TRP-2 Provide Potent Therapeutic Effect on Melanoma through Activation of Humoral and Cellular Immunity

    PubMed Central

    Avogadri, Francesca; Merghoub, Taha; Maughan, Maureen F.; Hirschhorn-Cymerman, Daniel; Morris, John; Ritter, Erika; Olmsted, Robert; Houghton, Alan N.; Wolchok, Jedd D.

    2010-01-01

    Background Malignant melanoma is the deadliest form of skin cancer and is refractory to conventional chemotherapy and radiotherapy. Therefore alternative approaches to treat this disease, such as immunotherapy, are needed. Melanoma vaccine design has mainly focused on targeting CD8+ T cells. Activation of effector CD8+ T cells has been achieved in patients, but provided limited clinical benefit, due to immune-escape mechanisms established by advanced tumors. We have previously shown that alphavirus-based virus-like replicon particles (VRP) simultaneously activate strong cellular and humoral immunity against the weakly immunogenic melanoma differentiation antigen (MDA) tyrosinase. Here we further investigate the antitumor effect and the immune mechanisms of VRP encoding different MDAs. Methodology/Principal Findings VRP encoding different MDAs were screened for their ability to prevent the growth of the B16 mouse transplantable melanoma. The immunologic mechanisms of efficacy were investigated for the most effective vaccine identified, focusing on CD8+ T cells and humoral responses. To this end, ex vivo immune assays and transgenic mice lacking specific immune effector functions were used. The studies identified a potent therapeutic VRP vaccine, encoding tyrosinase related protein 2 (TRP-2), which provided a durable anti-tumor effect. The efficacy of VRP-TRP2 relies on a novel immune mechanism of action requiring the activation of both IgG and CD8+ T cell effector responses, and depends on signaling through activating Fcγ receptors. Conclusions/Significance This study identifies a VRP-based vaccine able to elicit humoral immunity against TRP-2, which plays a role in melanoma immunotherapy and synergizes with tumor-specific CD8+ T cell responses. These findings will aid in the rational design of future immunotherapy clinical trials. PMID:20844763

  16. Targeted delivery of tumor antigens to activated dendritic cells via CD11c molecules induces potent antitumor immunity in mice.

    PubMed

    Wei, Huafeng; Wang, Suhui; Zhang, Dapeng; Hou, Sheng; Qian, Weizhu; Li, Bohua; Guo, Huaizu; Kou, Geng; He, Jinqiu; Wang, Hao; Guo, Yajun

    2009-07-15

    CD11c is an antigen receptor predominantly expressed on dendritic cells (DC), to which antigen targeting has been shown to induce robust antigen-specific immune responses. To facilitate targeted delivery of tumor antigens to DCs, we generated fusion proteins consisting of the extracellular domain of human HER or its rat homologue neu, fused to the single-chain fragment variable specific for CD11c (scFv(CD11c)-HER2/neu). Induction of cellular and humoral immune responses and antitumoral activity of the fusion proteins admixed with DC-activating CpG oligonucleotides (scFv(CD11c)-HER2/neu(CpG)) were tested in transplantable HER2/neu-expressing murine tumor models and in transgenic BALB-neuT mice developing spontaneous neu-driven mammary carcinomas. Vaccination of BALB/c mice with scFv(CD11c)-HER2(CpG) protected mice from subsequent challenge with HER2-positive, but not HER2-negative, murine breast tumor cells, accompanied by induction of strong HER2-specific T-cell and antibody responses. In a therapeutic setting, injection of scFv(CD11c)-HER2(CpG) caused rejection of established HER2-positive tumors. Importantly, antitumoral activity of such a fusion protein vaccine could be reproduced in immunotolerant BALB-neuT mice, where scFv(CD11c)-neu(CpG) vaccination significantly protected against a subsequent challenge with neu-expressing murine breast tumor cells and markedly delayed the onset of spontaneous mammary carcinomas. CD11c-targeted protein vaccines for in vivo delivery of tumor antigens to DCs induce potent immune responses and antitumoral activities and provide a rationale for further development of this approach for cancer immunotherapy.

  17. Discovery of a small molecule Tat-trans-activation-responsive RNA antagonist that potently inhibits human immunodeficiency virus-1 replication.

    PubMed

    Hwang, Seongwoo; Tamilarasu, Natarajan; Kibler, Karen; Cao, Hong; Ali, Akbar; Ping, Yueh-Hsin; Jeang, Kuan-Teh; Rana, Tariq M

    2003-10-03

    Antiretroviral therapy to treat AIDS uses molecules that target the reverse transcriptase and protease enzymes of human immunodeficiency virus, type 1 (HIV-1). A major problem associated with these treatments, however, is the emergence of drug-resistant strains. Thus, there is a compelling need to find drugs against other viral targets. One such target is the interaction between Tat, an HIV-1 regulatory protein essential for viral replication, and trans-activation-responsive (TAR) RNA. Here we describe the design and synthesis of an encoded combinatorial library containing 39,304 unnatural small molecules. Using a rapid high through-put screening technology, we identified 59 compounds. Structure-activity relationship studies led to the synthesis of 19 compounds that bind TAR RNA with high affinities. In the presence of a representative Tat-TAR inhibitor (5 microM TR87), we observed potent and sustained suppression of HIV replication in cultured cells over 24 days. The same concentration of this inhibitor did not exhibit any toxicity in cell cultures or in mice. TR87 was also shown to specifically disrupt Tat-TAR binding in vitro and inhibit Tat-mediated transcriptional activation in vitro and in vivo, providing a strong correlation between its activities and inhibition of HIV-1 replication. These results provide a structural scaffold for further development of new drugs, alone or in combination with other drugs, for treatment of HIV-1-infected individuals. Our results also suggest a general strategy for discovering pharmacophores targeting RNA structures that are essential in progression of other infectious, inflammatory, and genetic diseases.

  18. Liposomal short-chain C6 ceramide induces potent anti-osteosarcoma activity in vitro and in vivo.

    PubMed

    Zhai, Lei; Sun, Nan; Han, Zhe; Jin, Hai-chao; Zhang, Bo

    Osteosarcoma (OS) remains one deadly disease for many affected patients. The search for novel and more efficient anti-OS agents is urgent. In the current study, we demonstrated that liposome-packed C6 ceramide exerted potent cytotoxic effect against established (U2OS and MG-63 lines) and primary human OS cells. Meanwhile, the liposomal C6 (ceramide) induced caspase-mediated apoptotic death in OS cells. Liposomal C6 was significantly more potent than conventional free C6 in inhibiting OS cells, yet it was safe to non-cancerous bone cells (primary murine osteoblasts or human MLO-Y4 osteocytic cells). At the signaling level, we showed that liposomal C6 potently inhibited Akt activation in OS cells. Further studies revealed that a low dose of liposomal C6 dramatically sensitized the in vitro anti-OS activity of two conventional chemodrugs: methotrexate (MTX) and doxorubicin. In vivo, intravenous injection of liposomal C6 inhibited Akt activation and suppressed U2OS xenograft growth in nude mice without causing apparent toxicities. Meanwhile, when given at a low-dose (5 mg/kg body weight), liposomal C6 dramatically sensitized MTX's anti-U2OS activity in vivo. Collectively, our data demonstrate that liposomal C6 exerts potent anti-tumor activity in preclinical OS models. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Breast Milk of HIV-Positive Mothers Has Potent and Species-Specific In Vivo HIV-Inhibitory Activity

    PubMed Central

    Wahl, Angela; Baker, Caroline; Spagnuolo, Rae Ann; Stamper, Lisa W.; Fouda, Genevieve G.; Permar, Sallie R.; Hinde, Katie; Kuhn, Louise; Bode, Lars; Aldrovandi, Grace M.

    2015-01-01

    ABSTRACT Despite the nutritional and health benefits of breast milk, breast milk can serve as a vector for mother-to-child HIV transmission. Most HIV-infected infants acquire HIV through breastfeeding. Paradoxically, most infants breastfed by HIV-positive women do not become infected. This is potentially attributed to anti-HIV factors in breast milk. Breast milk of HIV-negative women can inhibit HIV infection. However, the HIV-inhibitory activity of breast milk from HIV-positive mothers has not been evaluated. In addition, while significant differences in breast milk composition between transmitting and nontransmitting HIV-positive mothers have been correlated with transmission risk, the HIV-inhibitory activity of their breast milk has not been compared. This knowledge may significantly impact the design of prevention approaches in resource-limited settings that do not deny infants of HIV-positive women the health benefits of breast milk. Here, we utilized bone marrow/liver/thymus humanized mice to evaluate the in vivo HIV-inhibitory activity of breast milk obtained from HIV-positive transmitting and nontransmitting mothers. We also assessed the species specificity and biochemical characteristics of milk's in vivo HIV-inhibitory activity and its ability to inhibit other modes of HIV infection. Our results demonstrate that breast milk of HIV-positive mothers has potent HIV-inhibitory activity and indicate that breast milk can prevent multiple routes of infection. Most importantly, this activity is unique to human milk. Our results also suggest multiple factors in breast milk may contribute to its HIV-inhibitory activity. Collectively, our results support current recommendations that HIV-positive mothers in resource-limited settings exclusively breastfeed in combination with antiretroviral therapy. IMPORTANCE Approximately 240,000 children become infected with HIV annually, the majority via breastfeeding. Despite daily exposure to virus in breast milk, most infants

  20. Combined activation of the energy and cellular-defense pathways may explain the potent anti-senescence activity of methylene blue.

    PubMed

    Atamna, Hani; Atamna, Wafa; Al-Eyd, Ghaith; Shanower, Gregory; Dhahbi, Joseph M

    2015-12-01

    Methylene blue (MB) delays cellular senescence, induces complex-IV, and activates Keap1/Nrf2; however, the molecular link of these effects to MB is unclear. Since MB is redox-active, we investigated its effect on the NAD/NADH ratio in IMR90 cells. The transient increase in NAD/NADH observed in MB-treated cells triggered an investigation of the energy regulator AMPK. MB induced AMPK phosphorylation in a transient pattern, which was followed by the induction of PGC1α and SURF1: both are inducers of mitochondrial and complex-IV biogenesis. Subsequently MB-treated cells exhibited >100% increase in complex-IV activity and a 28% decline in cellular oxidants. The telomeres erosion rate was also significantly lower in MB-treated cells. A previous research suggested that the pattern of AMPK activation (i.e., chronic or transient) determines the AMPK effect on cell senescence. We identified that the anti-senescence activity of MB (transient activator) was 8-times higher than that of AICAR (chronic activator). Since MB lacked an effect on cell cycle, an MB-dependent change to cell cycle is unlikely to contribute to the anti-senescence activity. The current findings in conjunction with the activation of Keap1/Nrf2 suggest a synchronized activation of the energy and cellular defense pathways as a possible key factor in MB's potent anti-senescence activity. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Role of the side chain stereochemistry in the α-glucosidase inhibitory activity of kotalanol, a potent natural α-glucosidase inhibitor. Part 2.

    PubMed

    Tanabe, Genzoh; Matsuoka, Kanjyun; Yoshinaga, Masahiro; Xie, Weijia; Tsutsui, Nozomi; A Amer, Mumen F; Nakamura, Shinya; Nakanishi, Isao; Wu, Xiaoming; Yoshikawa, Masayuki; Muraoka, Osamu

    2012-11-01

    To examine the role of the side chain of kotalanol (2), a potent natural α-glucosidase inhibitor isolated from Salacia reticulata, on inhibitory activity, four diastereomers (11a-11d) with reversed configuration (S) at the C-4' position in the side chain were synthesized and evaluated. Two of the four (11b and 11d) significantly lost their inhibitory activity against both maltase and sucrase, while the other two (11a and 11c) sustained the inhibitory activity to a considerable extent, showing distinct activity in response to the change of stereochemistry of the hydroxyls at the 5'and 6' positions. Different activities were rationalized with reference to in silico docking studies on these inhibitors with hNtMGAM. Against isomaltase, all four analogs showed potent inhibitory activity as well as 2, and 11b and 11d exhibited enzyme selectivity.

  2. Peptidomic analysis of skin secretions from the bullfrog Lithobates catesbeianus (Ranidae) identifies multiple peptides with potent insulin-releasing activity.

    PubMed

    Mechkarska, Milena; Ojo, Opeolu O; Meetani, Mohammed A; Coquet, Laurent; Jouenne, Thierry; Abdel-Wahab, Yasser H A; Flatt, Peter R; King, Jay D; Conlon, J Michael

    2011-02-01

    Using a combination of reversed-phase HPLC and electrospray mass spectrometry, peptidomic analysis of norepinephrine-stimulated skin secretions of the American bullfrog Lithobates catesbeianus Shaw, 1802 led to the identification and characterization of five newly described peptides (ranatuerin-1CBb, ranatuerin-2CBc, and -CBd, palustrin-2CBa, and temporin-CBf) together with seven peptides previously isolated on the basis of their antimicrobial activity (ranatuerin-1CBa, ranatuerin-2CBa, brevinin-1CBa, and -1CBb, temporin-CBa, -CBb, and -CBd). The abilities of the most abundant of the purified peptides to stimulate the release of insulin from the rat BRIN-BD11 clonal β cell line were evaluated. Ranatuerin-2CBd (GFLDIIKNLGKTFAGHMLDKIRCTIGTCPPSP) was the most potent peptide producing a significant stimulation of insulin release (119% of basal rate, P<0.01) from BRIN-BD11 cells at a concentration of 30nM, with a maximum response (236% of basal rate, P<0.001) at a concentration of 3μM. Ranatuerin-2CBd did not stimulate release of the cytosolic enzyme, lactate dehydrogenase at concentrations up to 3μM, indicating that the integrity of the plasma membrane had been preserved. Brevinin-1CBb (FLPFIARLAAKVFPSIICSVTKKC) produced the maximum stimulation of insulin release (285% of basal rate, P<0.001 at 3μM) but the peptide was cytotoxic at this concentration.

  3. P1-substituted symmetry-based human immunodeficiency virus protease inhibitors with potent antiviral activity against drug-resistant viruses.

    PubMed

    Degoey, David A; Grampovnik, David J; Chen, Hui-Ju; Flosi, William J; Klein, Larry L; Dekhtyar, Tatyana; Stoll, Vincent; Mamo, Mulugeta; Molla, Akhteruzzaman; Kempf, Dale J

    2011-10-27

    Because there is currently no cure for HIV infection, patients must remain on long-term drug therapy, leading to concerns over potential drug side effects and the emergence of drug resistance. For this reason, new and safe antiretroviral agents with improved potency against drug-resistant strains of HIV are needed. A series of HIV protease inhibitors (PIs) with potent activity against both wild-type (WT) virus and drug-resistant strains of HIV was designed and synthesized. The incorporation of substituents with hydrogen bond donor and acceptor groups at the P1 position of our symmetry-based inhibitor series resulted in significant potency improvements against the resistant mutants. By this approach, several compounds, such as 13, 24, and 29, were identified that demonstrated similar or improved potencies compared to 1 against highly mutated strains of HIV derived from patients who previously failed HIV PI therapy. Overall, compound 13 demonstrated the best balance of potency against drug resistant strains of HIV and oral bioavailability in pharmacokinetic studies. X-ray analysis of an HIV PI with an improved resistance profile bound to WT HIV protease is also reported.

  4. Structure-activity relationship studies of pyrimidine-2,4-dione derivatives as potent P2X7 receptor antagonists.

    PubMed

    Park, Jin-Hee; Lee, Ga-Eun; Lee, So-Deok; Ko, Hyojin; Kim, Yong-Chul

    2015-12-01

    As an optimization strategy, the flexible structure of KN-62, a known P2X7 receptor antagonist, was converted into conformationally constrained derivatives using pyrimidine-2,4-dione as the core skeleton. Various modifications at the 4-position of the piperazine moiety of the new lead compound were performed to improve P2X7 receptor antagonistic activities, which were evaluated in HEK293 cells stably expressing the human P2X7 receptor (EtBr uptake assay) and in THP-1 cells (IL-1β ELISA assay). According to the results, polycycloalkyl acyl or di-halogenated benzoyl substituents were much more favorable than the original phenyl group of KN-62. Among these compounds, the trifluoromethyl-chloro benzoyl derivative 18 m and adamantyl carbonyl derivatives 19 g-19 i and 19k showed potent antagonistic effects, with IC50 values ranging from 10 to 30 nM. In addition, the in vitro adsorption, distribution, metabolism, excretion, and toxicity (ADMET) profile of 18 m was determined to be in acceptable ranges in terms of metabolic stability and cytotoxicity. These results suggest that pyrimidine-2,4-dione derivatives may be promising novel P2X7 receptor antagonists for the development of anti-inflammatory drugs. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  5. P1-Substituted Symmetry-Based Human Immunodeficiency Virus Protease Inhibitors with Potent Antiviral Activity against Drug-Resistant Viruses

    SciTech Connect

    DeGoey, David A.; Grampovnik, David J.; Chen, Hui-Ju; Flosi, William J.; Klein, Larry L.; Dekhtyar, Tatyana; Stoll, Vincent; Mamo, Mulugeta; Molla, Akhteruzzaman; Kempf, Dale J.

    2013-03-07

    Because there is currently no cure for HIV infection, patients must remain on long-term drug therapy, leading to concerns over potential drug side effects and the emergence of drug resistance. For this reason, new and safe antiretroviral agents with improved potency against drug-resistant strains of HIV are needed. A series of HIV protease inhibitors (PIs) with potent activity against both wild-type (WT) virus and drug-resistant strains of HIV was designed and synthesized. The incorporation of substituents with hydrogen bond donor and acceptor groups at the P1 position of our symmetry-based inhibitor series resulted in significant potency improvements against the resistant mutants. By this approach, several compounds, such as 13, 24, and 29, were identified that demonstrated similar or improved potencies compared to 1 against highly mutated strains of HIV derived from patients who previously failed HIV PI therapy. Overall, compound 13 demonstrated the best balance of potency against drug resistant strains of HIV and oral bioavailability in pharmacokinetic studies. X-ray analysis of an HIV PI with an improved resistance profile bound to WT HIV protease is also reported.

  6. Synergistic anti-tumor therapy by a comb-like multifunctional antibody nanoarray with exceptionally potent activity

    NASA Astrophysics Data System (ADS)

    Li, Huafei; Sun, Yun; Chen, Di; Zhao, He; Zhao, Mengxin; Zhu, Xiandi; Ke, Changhong; Zhang, Ge; Jiang, Cheng; Zhang, Li; Zhang, Fulei; Wei, Huafeng; Li, Wei

    2015-10-01

    Simultaneously blocking multiple mediators offers new hope for the treatment of complex diseases. However, the curative potential of current combination therapy by chronological administration of separate monoclonal antibodies (mAbs) or multi-specific mAbs is still moderate due to inconvenient manipulation, low cooperative effectors, poor pharmacokinetics and insufficient tumor accumulation. Here, we describe a facile strategy that arms distinct mAbs with cooperative effectors onto a long chain to form a multicomponent comb-like nano mAb. Unlike dissociative parental mAbs, the multifunctional mAb nanoarray (PL-RB) constructed from type I/II anti-CD20 mAbs shows good pharmacokinetics. This PL-RB simultaneously targets distinct epitopes on a single antigen (Ag) and neighboring Ags on different lymphocytes. This unique intra- and intercellular Ag cross-linking endows the multifunctional mAb nanoarray with potent apoptosis activity. The exceptional apoptosis, complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) that are synchronously evoked by the nano PL-RB are further synergistically promoted via enhanced permeability and retention (EPR), which resulted in high intratumor accumulation and excellent anti-lymphoma efficiency.

  7. Novel 4-anilinoquinazoline derivatives featuring an 1-adamantyl moiety as potent EGFR inhibitors with enhanced activity against NSCLC cell lines.

    PubMed

    Yu, Haiqing; Li, Yanxia; Ge, Yang; Song, Zhendong; Wang, Changyuan; Huang, Shanshan; Jin, Yue; Han, Xu; Zhen, Yuhong; Liu, Kexin; Zhou, Youwen; Ma, Xiaodong

    2016-03-03

    With the aim of overcoming gefitinib resistance, a series of novel quinazoline derivatives bearing an adamantyl group on the aniline ring were synthesized as potent epidermal growth factor receptor (EGFR) inhibitors. Most of these analogues are comparable to gefitinib in their ability to inhibit non-small cell lung cancer (NSCLC) cell lines, and several also exhibited significantly enhanced anti-tumor potency. Specifically, compound 3d, with an IC50 value of 2.06 μM against A431 cells with the wild-type EGFR and of 0.009 μM against the gefitinib-sensitive cells, displayed approximately 5-fold higher potency than the lead compound to inhibit the cells harboring the EGFR(T790M) mutant. In addition, the molecular simulation and Western blot analysis results also indicated that these compounds effectively interfered with the EGFR(T790M) activity, and may serve as a new alternative structure to develop more effective antitumor agents.

  8. Applying a multitarget rational drug design strategy: the first set of modulators with potent and balanced activity toward dopamine D3 receptor and fatty acid amide hydrolase.

    PubMed

    De Simone, Alessio; Ruda, Gian Filippo; Albani, Clara; Tarozzo, Glauco; Bandiera, Tiziano; Piomelli, Daniele; Cavalli, Andrea; Bottegoni, Giovanni

    2014-05-18

    Combining computer-assisted drug design and synthetic efforts, we generated compounds with potent and balanced activities toward both D3 dopamine receptor and fatty acid amide hydrolase (FAAH) enzyme. By concurrently modulating these targets, our compounds hold great potential toward exerting a disease-modifying effect on nicotine addiction and other forms of compulsive behavior.

  9. LLY-507, a cell-active, potent, and selective inhibitor of protein-lysine methyltransferase SMYD2

    DOE PAGES

    Nguyen, Hannah; Allali-Hassani, Abdellah; Antonysamy, Stephen; ...

    2015-03-30

    SMYD2 is a lysine methyltransferase that catalyzes the monomethylation of several protein substrates including p53. SMYD2 is overexpressed in a significant percentage of esophageal squamous primary carcinomas, and that overexpression correlates with poor patient survival. However, the mechanism(s) by which SMYD2 promotes oncogenesis is not understood. A small molecule probe for SMYD2 would allow for the pharmacological dissection of this biology. In this report, we disclose LLY-507, a cell-active, potent small molecule inhibitor of SMYD2. LLY-507 is >100-fold selective for SMYD2 over a broad range of methyltransferase and non-methyltransferase targets. A 1.63-Å resolution crystal structure of SMYD2 in complex withmore » LLY-507 shows the inhibitor binding in the substrate peptide binding pocket. LLY-507 is active in cells as measured by reduction of SMYD2-induced monomethylation of p53 Lys(370) at submicromolar concentrations. We used LLY-507 to further test other potential roles of SMYD2. Mass spectrometry-based proteomics showed that cellular global histone methylation levels were not significantly affected by SMYD2 inhibition with LLY-507, and subcellular fractionation studies indicate that SMYD2 is primarily cytoplasmic, suggesting that SMYD2 targets a very small subset of histones at specific chromatin loci and/or non-histone substrates. Breast and liver cancers were identified through in silico data mining as tumor types that display amplification and/or overexpression of SMYD2. LLY-507 inhibited the proliferation of several esophageal, liver, and breast cancer cell lines in a dose-dependent manner. As a result, these findings suggest that LLY-507 serves as a valuable chemical probe to aid in the dissection of SMYD2 function in cancer and other biological processes.« less

  10. LLY-507, a Cell-active, Potent, and Selective Inhibitor of Protein-lysine Methyltransferase SMYD2.

    PubMed

    Nguyen, Hannah; Allali-Hassani, Abdellah; Antonysamy, Stephen; Chang, Shawn; Chen, Lisa Hong; Curtis, Carmen; Emtage, Spencer; Fan, Li; Gheyi, Tarun; Li, Fengling; Liu, Shichong; Martin, Joseph R; Mendel, David; Olsen, Jonathan B; Pelletier, Laura; Shatseva, Tatiana; Wu, Song; Zhang, Feiyu Fred; Arrowsmith, Cheryl H; Brown, Peter J; Campbell, Robert M; Garcia, Benjamin A; Barsyte-Lovejoy, Dalia; Mader, Mary; Vedadi, Masoud

    2015-05-29

    SMYD2 is a lysine methyltransferase that catalyzes the monomethylation of several protein substrates including p53. SMYD2 is overexpressed in a significant percentage of esophageal squamous primary carcinomas, and that overexpression correlates with poor patient survival. However, the mechanism(s) by which SMYD2 promotes oncogenesis is not understood. A small molecule probe for SMYD2 would allow for the pharmacological dissection of this biology. In this report, we disclose LLY-507, a cell-active, potent small molecule inhibitor of SMYD2. LLY-507 is >100-fold selective for SMYD2 over a broad range of methyltransferase and non-methyltransferase targets. A 1.63-Å resolution crystal structure of SMYD2 in complex with LLY-507 shows the inhibitor binding in the substrate peptide binding pocket. LLY-507 is active in cells as measured by reduction of SMYD2-induced monomethylation of p53 Lys(370) at submicromolar concentrations. We used LLY-507 to further test other potential roles of SMYD2. Mass spectrometry-based proteomics showed that cellular global histone methylation levels were not significantly affected by SMYD2 inhibition with LLY-507, and subcellular fractionation studies indicate that SMYD2 is primarily cytoplasmic, suggesting that SMYD2 targets a very small subset of histones at specific chromatin loci and/or non-histone substrates. Breast and liver cancers were identified through in silico data mining as tumor types that display amplification and/or overexpression of SMYD2. LLY-507 inhibited the proliferation of several esophageal, liver, and breast cancer cell lines in a dose-dependent manner. These findings suggest that LLY-507 serves as a valuable chemical probe to aid in the dissection of SMYD2 function in cancer and other biological processes. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. The angular structure of ONC201, a TRAIL pathway-inducing compound, determines its potent anti-cancer activity.

    PubMed

    Wagner, Jessica; Kline, Christina Leah; Pottorf, Richard S; Nallaganchu, Bhaskara Rao; Olson, Gary L; Dicker, David T; Allen, Joshua E; El-Deiry, Wafik S

    2014-12-30

    We previously identified TRAIL-inducing compound 10 (TIC10), also known as NSC350625 or ONC201, from a NCI chemical library screen as a small molecule that has potent anti-tumor efficacy and a benign safety profile in preclinical cancer models. The chemical structure that was originally published by Stahle, et. al. in the patent literature was described as an imidazo[1,2-a]pyrido[4,3-d]pyrimidine derivative. The NCI and others generally accepted this as the correct structure, which was consistent with the mass spectrometry analysis outlined in the publication by Allen et. al. that first reported the molecule's anticancer properties. A recent publication demonstrated that the chemical structure of ONC201 material from the NCI is an angular [3,4-e] isomer of the originally disclosed, linear [4,3-d] structure. Here we confirm by NMR and X-ray structural analysis of the dihydrochloride salt form that the ONC201 material produced by Oncoceutics is the angular [3,4-e] structure and not the linear structure originally depicted in the patent literature and by the NCI. Similarly, in accordance with our biological evaluation, the previously disclosed anti-cancer activity is associated with the angular structure and not the linear isomer. Together these studies confirm that ONC201, produced by Oncoceutics or obtained from the NCI, possesses an angular [3,4-e] structure that represents the highly active anti-cancer compound utilized in prior preclinical studies and now entering clinical trials in advanced cancers.

  12. LLY-507, a cell-active, potent, and selective inhibitor of protein-lysine methyltransferase SMYD2

    SciTech Connect

    Nguyen, Hannah; Allali-Hassani, Abdellah; Antonysamy, Stephen; Chang, Shawn; Chen, Lisa Hong; Curtis, Carmen; Emtage, Spencer; Fan, Li; Gheyi, Tarun; Li, Fengling; Liu, Shichong; Martin, Joseph R.; Mendel, David; Olsen, Jonathan B.; Pelletier, Laura; Shatseva, Tatiana; Wu, Song; Zhang, Feiyu Fred; Arrowsmith, Cheryl H.; Brown, Peter J.; Campbell, Robert M.; Garcia, Benjamin A.; Barsyte-Lovejoy, Dalia; Mader, Mary; Vedadi, Masoud

    2015-03-30

    SMYD2 is a lysine methyltransferase that catalyzes the monomethylation of several protein substrates including p53. SMYD2 is overexpressed in a significant percentage of esophageal squamous primary carcinomas, and that overexpression correlates with poor patient survival. However, the mechanism(s) by which SMYD2 promotes oncogenesis is not understood. A small molecule probe for SMYD2 would allow for the pharmacological dissection of this biology. In this report, we disclose LLY-507, a cell-active, potent small molecule inhibitor of SMYD2. LLY-507 is >100-fold selective for SMYD2 over a broad range of methyltransferase and non-methyltransferase targets. A 1.63-Å resolution crystal structure of SMYD2 in complex with LLY-507 shows the inhibitor binding in the substrate peptide binding pocket. LLY-507 is active in cells as measured by reduction of SMYD2-induced monomethylation of p53 Lys(370) at submicromolar concentrations. We used LLY-507 to further test other potential roles of SMYD2. Mass spectrometry-based proteomics showed that cellular global histone methylation levels were not significantly affected by SMYD2 inhibition with LLY-507, and subcellular fractionation studies indicate that SMYD2 is primarily cytoplasmic, suggesting that SMYD2 targets a very small subset of histones at specific chromatin loci and/or non-histone substrates. Breast and liver cancers were identified through in silico data mining as tumor types that display amplification and/or overexpression of SMYD2. LLY-507 inhibited the proliferation of several esophageal, liver, and breast cancer cell lines in a dose-dependent manner. As a result, these findings suggest that LLY-507 serves as a valuable chemical probe to aid in the dissection of SMYD2 function in cancer and other biological processes.

  13. COH-203, a novel microtubule inhibitor, exhibits potent anti-tumor activity via p53-dependent senescence in hepatocellular carcinoma

    SciTech Connect

    Qi, Huan; Zuo, Dai-Ying; Bai, Zhao-Shi; Xu, Jing-Wen; Li, Zeng-Qiang; Shen, Qi-Rong; Wang, Zhi-Wei; Zhang, Wei-Ge; Wu, Ying-Liang

    2014-12-12

    Highlights: • COH-203 exhibits anti-hepatoma effects in vitro and in vivo with low toxicity. • COH-203 inhibits tubulin polymerization. • COH-203 induces mitotic arrest followed by mitotic slippage in BEL-7402 cells. • COH-203 induces p53-dependent senescence in BEL-7402 cells. - Abstract: 5-(3-Hydroxy-4-methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-3H-1, 2-dithiol-3-one (COH-203) is a novel synthesized analogue of combretastatin A-4 that can be classified as a microtubule inhibitor. In this study, we evaluated the anti-hepatoma effect of COH-203 in vitro and in vivo and explored the underlying molecular mechanisms. COH-203 was shown to be more effective in inhibiting the proliferation of liver cancer cells compared with normal liver cells. COH-203 also displayed potent anti-tumor activity in a hepatocellular carcinoma xenograft model without significant toxicity. Mechanistic studies demonstrated that treatment with COH-203 induced mitotic arrest by inhibiting tubulin polymerization in BEL-7402 liver cancer cells. Long-term COH-203 treatment in BEL-7402 cells led to mitotic slippage followed by senescence via the p14{sup Arf}–p53–p21 and p16{sup INK4α}–Rb pathways. Furthermore, suppression of p53 via pifithrin-α (p53 inhibitor) and p53-siRNA attenuated COH-203-induced senescence in BEL-7402 cells, suggesting that COH-203 induced senescence p53-dependently. In conclusion, we report for the first time that COH-203, one compound in the combretastatin family, promotes anti-proliferative activity through the induction of p-53 dependent senescence. Our findings will provide a molecular rationale for the development of COH-203 as a promising anti-tumor agent.

  14. Potent and Targeted Activation of Latent HIV-1 Using the CRISPR/dCas9 Activator Complex.

    PubMed

    Saayman, Sheena M; Lazar, Daniel C; Scott, Tristan A; Hart, Jonathan R; Takahashi, Mayumi; Burnett, John C; Planelles, Vicente; Morris, Kevin V; Weinberg, Marc S

    2016-03-01

    HIV-1 provirus integration results in a persistent latently infected reservoir that is recalcitrant to combined antiretroviral therapy (cART) with lifelong treatment being the only option. The "shock and kill" strategy aims to eradicate latent HIV by reactivating proviral gene expression in the context of cART treatment. Gene-specific transcriptional activation can be achieved using the RNA-guided CRISPR-Cas9 system comprising single guide RNAs (sgRNAs) with a nuclease-deficient Cas9 mutant (dCas9) fused to the VP64 transactivation domain (dCas9-VP64). We engineered this system to target 23 sites within the long terminal repeat promoter of HIV-1 and identified a "hotspot" for activation within the viral enhancer sequence. Activating sgRNAs transcriptionally modulated the latent proviral genome across multiple different in vitro latency cell models including T cells comprising a clonally integrated mCherry-IRES-Tat (LChIT) latency system. We detected consistent and effective activation of latent virus mediated by activator sgRNAs, whereas latency reversal agents produced variable activation responses. Transcriptomic analysis revealed dCas9-VP64/sgRNAs to be highly specific, while the well-characterized chemical activator TNFα induced widespread gene dysregulation. CRISPR-mediated gene activation represents a novel system which provides enhanced efficiency and specificity in a targeted latency reactivation strategy and represents a promising approach to a "functional cure" of HIV/AIDS.

  15. Antimicrobial and anti-Quorum Sensing activities of selected medicinal plants of Ethiopia: Implication for development of potent antimicrobial agents.

    PubMed

    Bacha, Ketema; Tariku, Yinebeb; Gebreyesus, Fisseha; Zerihun, Shibru; Mohammed, Ali; Weiland-Bräuer, Nancy; Schmitz, Ruth A; Mulat, Mulugeta

    2016-07-11

    Traditional medicinal plants have been used as an alternative medicine in many parts of the world, including Ethiopia. There are many documented scientific reports on antimicrobial activities of the same. To our knowledge, however, there is no report on the anti-Quorum Sensing (Quorum Quenching, QQ) potential of traditional Ethiopian medicinal plants. As many of the opportunistic pathogenic bacteria depend on Quorum Sensing (QS) systems to coordinate their virulence expression, interference with QS could be a novel approach to control bacterial infections. Thus, the aim of this study was to evaluate selected medicinal plants from Ethiopia for their antimicrobial activities against bacterial and fungal pathogens; and to assess the interference of these plant extracts with QS of bacteria. Antimicrobial activities of plant extracts (oil, resins and crude extracts) were evaluated following standard agar diffusion technique. The minimum inhibitory concentrations (MIC) of potent extracts were determined using 96 well micro-titer plates and optical densities were measured using an ELISA Microplate reader. Interference with Quorum Sensing activities of extracts was determined using the recently established E. coli based reporter strain AI1-QQ.1 and signaling molecule N-(ß-ketocaproyl)-L-homoserine lactone (3-oxo-C6-HSL). Petroleum ether extract of seed of Nigella sativa exhibited the highest activity against both the laboratory isolated Bacillus cereus [inhibition zone (IZ), 44 ± 0.31 mm] and B. cereus ATCC 10987 (IZ, 40 ± 2.33 mm). Similarly, oil extract from mature ripe fruit husk of Aframomum corrorima and mature unripe fruit of A. corrorima revealed promising activities against Candida albicans ATCC 90028 (IZ, 35 ± 1.52 mm) and Staphylococcus aureus DSM 346 (IZ, 25 ± 1.32 mm), respectively. Antimicrobial activities of oil extract from husk of A. corrorima and petroleum ether extract of seed of N. sativa were significantly higher than that of

  16. Synthesis and Evaluation of 1,5-Disubstituted Tetrazoles as Rigid Analogues of Combretastatin A-4 with Potent Antiproliferative and Antitumor Activity

    PubMed Central

    Romagnoli, Romeo; Baraldi, Pier Giovanni; Salvador, Maria Kimatrai; Preti, Delia; Tabrizi, Mojgan Aghazadeh; Brancale, Andrea; Fu, Xian-Hua; Li, Jun; Zhang, Su-Zhan; Hamel, Ernest; Bortolozzi, Roberta; Basso, Giuseppe; Viola, Giampietro

    2012-01-01

    Tubulin, the major structural component of microtubules, is a target for the development of anticancer agents. Two series of 1,5-diaryl substituted 1,2,3,4-tetrazoles were concisely synthesized, using a palladium-catalyzed cross-coupling reaction, and identified as potent antiproliferative agents and novel tubulin polymerization inhibitors that act at the colchicine site. SAR analysis indicated that compounds with a 4-ethoxyphenyl group at the N-1 or C-5 position of the 1,2,3,4-tetrazole ring exhibited maximal activity. Several of these compounds also had potent activity in inhibiting the growth of multidrug resistant cells overexpressing P-glycoprotein. Active compounds induced apoptosis through the mitochondrial pathway with activation of caspase-9 and caspase-3. Furthermore, compound 4l significantly reduced in vivo the growth of the HT-29 xenograft in a nude mouse model, suggesting that 4l is a promising new antimitotic agent with clinical potential. PMID:22136312

  17. Nonsteroidal anti-inflammatory drug flufenamic acid is a potent activator of AMP-activated protein kinase.

    PubMed

    Chi, Yuan; Li, Kai; Yan, Qiaojing; Koizumi, Schuichi; Shi, Liye; Takahashi, Shuhei; Zhu, Ying; Matsue, Hiroyuki; Takeda, Masayuki; Kitamura, Masanori; Yao, Jian

    2011-10-01

    Flufenamic acid (FFA) is a nonsteroidal anti-inflammatory drug (NSAID). It has anti-inflammatory and antipyretic properties. In addition, it modulates multiple channel activities. The mechanisms underlying the pharmacological actions of FFA are presently unclear. Given that AMP-activated protein kinase (AMPK) has both anti-inflammatory and channel-regulating functions, we examined whether FFA induces AMPK activation. 1) Exposure of several different types of cells to FFA resulted in an elevation of AMPKα phosphorylation at Thr172. This effect of FFA was reproduced by functionally and structurally similar mefenamic acid, tolfenamic acid, niflumic acid, and meclofenamic acid. 2) FFA-induced activation of AMPK was largely abolished by the treatment of cells with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl ester) (an intracellular Ca(2+) chelator) or depletion of extracellular Ca(2+), whereas it was mimicked by stimulation of cells with the Ca(2+) ionophore 5-(methylamino)-2-({(2R,3R,6S,8S,9R,11R)-3,9,11-trimethyl-8-[(1S)-1-methyl-2-oxo-2-(1H-pyrrol-2-yl)ethyl]-1,7-dioxaspiro[5.5]undec-2-yl}methyl)-1,3-benzoxazole-4-carboxylic acid (A23187) or ionomycin. 3) FFA triggered a rise in intracellular Ca(2+), which was abolished by cyclosporine, a blocker of mitochondrial permeability transition pore. Cyclosporine also abolished FFA-induced activation of AMPK. 4) Inhibition of Ca(2+)/calmodulin-dependent kinase kinase β (CaMKKβ) with 7-oxo-7H-benzimidazo[2,1-a]benz[de]isoquinoline-3-carboxylic acid acetate (STO-609) or down-regulation of CaMKKβ with short interfering RNA largely abrogated FFA-induced activation of AMPK. 5) FFA significantly suppressed nuclear factor-κB activity and inducible nitric-oxide synthase expression triggered by interleukin-1β and tumor necrosis factor α. This suppression was also largely abrogated by STO-609. Taken together, we conclude that FFA induces AMPK activation through the Ca(2+)-CaMKKβ pathway

  18. Role of the side chain stereochemistry in the α-glucosidase inhibitory activity of kotalanol, a potent natural α-glucosidase inhibitor.

    PubMed

    Xie, Weijia; Tanabe, Genzoh; Matsuoka, Kanjyun; Amer, Mumen F A; Minematsu, Toshie; Wu, Xiaoming; Yoshikawa, Masayuki; Muraoka, Osamu

    2011-04-01

    Synthesis and evaluation of four diastereomers (9a, 9b, 9c and 9d) of kotalanol, a potent α-glucosidase inhibitor isolated from an Ayurvedic medicinal plant Salacia species, are described. Stereo-inversion at C-3' and C-4' of kotalanol (2) caused significant decrease of the inhibitory activities against maltase and sucrase, whereas inhibitory activity against isomaltase sustained, thus resulted in exerting selectivity against isomaltase.

  19. Potent HGF/c-Met axis inhibitors from Eucalyptus globulus: the coupling of phloroglucinol and sesquiterpenoid is essential for the activity.

    PubMed

    Yang, Sheng-Ping; Zhang, Xiao-Wei; Ai, Jing; Gan, Li-She; Xu, Jin-Biao; Wang, Ying; Su, Zu-Shang; Wang, Lu; Ding, Jian; Geng, Mei-Yu; Yue, Jian-Min

    2012-09-27

    Eucalyptin A (1), together with two known compounds 2 and 3 exhibiting potent inhibition on HGF/c-Met axis, was discovered from the fruits of Eucalyptus globulus. 1 possessed an unprecedented carbon framework of phloroglucinol-coupled sesquiterpenoid, and its structure was elucidated by spectroscopic method and ECD calculation. A brief structure-activity relationship discussion indicated that the coupling of a phloroglucinol and a sesquiterpenoid is essential for the activity.

  20. Potent β-Lactam Enhancer Activity of Zidebactam and WCK 5153 against Acinetobacter baumannii, Including Carbapenemase-Producing Clinical Isolates.

    PubMed

    Moya, Bartolome; Barcelo, Isabel M; Bhagwat, Sachin; Patel, Mahesh; Bou, German; Papp-Wallace, Krisztina M; Bonomo, Robert A; Oliver, Antonio

    2017-08-28

    Multidrug-resistant Acinetobacter baumannii has rapidly spread worldwide resulting in a serious threat to hospitalized patients. Zidebactam and WCK 5153 are novel non-β-lactam bicyclo-acyl hydrazide β-lactam enhancer antibiotics being developed to target multidrug-resistant A. baumannii. The objectives of this work were to determine the penicillin-binding protein (PBP) IC50s, OXA-23 inhibition profiles, and antimicrobial activities of zidebactam and WCK 5153, alone and in combination with β-lactams, against multidrug-resistant A. baumannii MICs and time kill kinetics were performed against an A. baumannii clinical strain producing the carbapenemase OXA-23 and belonging to the widespread European clone II, sequence type 2 (ST2). Inhibition of OXA-23 purified enzyme by zidebactam, WCK 5153, and comparators was assessed. All of the compounds tested displayed Ki app values >100 μM indicating poor OXA-23 β-lactamase inhibition. The PBP IC50 values of zidebactam, WCK 5153, cefepime, ceftazidime, meropenem and sulbactam (range of concentrations tested 0.02 - 2 μg/mL) were also determined. Zidebactam and WCK 5153 demonstrated specific high-affinity PBP2 binding in A. baumannii (0.01 μg/mL for both of the compounds). MICs of zidebactam and WCK 5153 were >1024 μg/mL for wild-type and multidrug-resistant Acinetobacter spp. strains. Importantly, combinations of cefepime or sulbactam with 8 μg/mL of zidebactam or WCK 5153 led to a 4- and 8-fold MIC reduction, respectively and showed enhanced killing. Notably, several of the combinations resulted in full bacterial eradication at 24h. We conclude that zidebactam and WCK 5153 are PBP2 inhibitors that show potent β-lactam enhancer effect against A. baumannii, including a multidrug-resistant OXA-23-producing ST2 international clone. Copyright © 2017 American Society for Microbiology.

  1. Parallel Functional Activity Profiling Reveals Valvulopathogens Are Potent 5-Hydroxytryptamine2B Receptor Agonists: Implications for Drug Safety Assessment

    PubMed Central

    Huang, Xi-Ping; Setola, Vincent; Yadav, Prem N.; Allen, John A.; Rogan, Sarah C.; Hanson, Bonnie J.; Revankar, Chetana; Robers, Matt; Doucette, Chris

    2009-01-01

    Drug-induced valvular heart disease (VHD) is a serious side effect of a few medications, including some that are on the market. Pharmacological studies of VHD-associated medications (e.g., fenfluramine, pergolide, methysergide, and cabergoline) have revealed that they and/or their metabolites are potent 5-hydroxytryptamine2B (5-HT2B) receptor agonists. We have shown that activation of 5-HT2B receptors on human heart valve interstitial cells in vitro induces a proliferative response reminiscent of the fibrosis that typifies VHD. To identify current or future drugs that might induce VHD, we screened approximately 2200 U.S. Food and Drug Administration (FDA)-approved or investigational medications to identify 5-HT2B receptor agonists, using calcium-based high-throughput screening. Of these 2200 compounds, 27 were 5-HT2B receptor agonists (hits); 14 of these had previously been identified as 5-HT2B receptor agonists, including seven bona fide valvulopathogens. Six of the hits (guanfacine, quinidine, xylometazoline, oxymetazoline, fenoldopam, and ropinirole) are approved medications. Twenty-three of the hits were then “functionally profiled” (i.e., assayed in parallel for 5-HT2B receptor agonism using multiple readouts to test for functional selectivity). In these assays, the known valvulopathogens were efficacious at concentrations as low as 30 nM, whereas the other compounds were less so. Hierarchical clustering analysis of the pEC50 data revealed that ropinirole (which is not associated with valvulopathy) was clearly segregated from known valvulopathogens. Taken together, our data demonstrate that patterns of 5-HT2B receptor functional selectivity might be useful for identifying compounds likely to induce valvular heart disease. PMID:19570945

  2. In situ anticariogenic activity of free fatty acids after sucrose exposure to oral biofilms formed on enamel.

    PubMed

    Giacaman, Rodrigo A; Valenzuela-Ramos, Ricardo; Muñoz-Sandoval, Cecilia

    2016-04-01

    To test whether the effect of sucrose on enamel is hampered by immediate free fatty acids exposure to the oral biofilm formed under a highly cariogenic environment, in situ. A split-mouth, cross-over and double-blind in situ experiment was carried out with 11 volunteers who wore palatal appliances containing bovine enamel slabs. In two 15-day phases, volunteers dripped 20% sucrose onto the slabs eight times per/day for 5 minutes followed by 5 additional minutes with suspensions of 10 mM oleic, linoleic or stearic acid or sucrose (caries-positive control), four times/day. Biofilms were analyzed for biomass, bacteria and polysaccharide formation and enamel demineralization was estimated by surface microhardness. Biofilms exposed to oleic and linoleic acids showed significantly lower biomass than the control. S. mutans counts were reduced upon linoleic acid exposure (P< 0.05). All free fatty acids reduced polysaccharide formation (P < 0.05). Slabs exposed to 20% sucrose followed by free fatty acids had significantly lower demineralization than those exposed to sucrose alone, with reductions of 33%, 27% and 20% for linoleic, oleic and stearic acid, respectively. Data suggest that unsaturated free fatty acids exposed after sucrose might potentially reduce cariogenicity of the oral biofilm formed on enamel in situ, but further clinical confirmation is required.

  3. Structure-activity relationship study of 4-(thiazol-5-yl)benzoic acid derivatives as potent protein kinase CK2 inhibitors.

    PubMed

    Ohno, Hiroaki; Minamiguchi, Daiki; Nakamura, Shinya; Shu, Keito; Okazaki, Shiho; Honda, Maho; Misu, Ryosuke; Moriwaki, Hirotomo; Nakanishi, Shinsuke; Oishi, Shinya; Kinoshita, Takayoshi; Nakanishi, Isao; Fujii, Nobutaka

    2016-03-01

    Two classes of modified analogs of 4-(thiazol-5-yl)benzoic acid-type CK2 inhibitors were designed. The azabenzene analogs, pyridine- and pyridazine-carboxylic acid derivatives, showed potent protein kinase CK2 inhibitory activities [IC50 (CK2α)=0.014-0.017μM; IC50 (CK2α')=0.0046-0.010μM]. Introduction of a 2-halo- or 2-methoxy-benzyloxy group at the 3-position of the benzoic acid moiety maintained the potent CK2 inhibitory activities [IC50 (CK2α)=0.014-0.016μM; IC50 (CK2α')=0.0088-0.014μM] and led to antiproliferative activities [CC50 (A549)=1.5-3.3μM] three to six times higher than those of the parent compound. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Targeted Antibiotic Delivery: Selective Siderophore Conjugation with Daptomycin Confers Potent Activity Against Multi-Drug Resistant Acinetobacter baumannii Both in vitro and in vivo.

    PubMed

    Ghosh, Manuka; Miller, Patricia A; Möllmann, Ute; Claypool, William D; Schroeder, Valerie A; Wolter, William R; Suckow, Mark; Yu, Honglin; Li, Shuang; Huang, Weiqiang; Zajicek, Jaroslav; Miller, Marvin J

    2017-03-13

    In order to address the dire need for new antibiotics to treat specific strains of drug resistant Gram-negative bacterial infections, a mixed ligand analog of the natural Acinetobacter baumannii selective siderophore, fimsbactin, was coupled to daptomycin, a Gram-positive only antibiotic. The resulting conjugate, 11, has potent activity against multi-drug resistant strains of A. baumannii, both in vitro and in vivo. The study also indicates that conjugation of siderophores to "drugs" that are much larger than the siderophore (iron transport agent) itself facilitates active uptake that circumvents the normal permeability problems in Gram-negative bacteria. The results demonstrate the ability to extend activity of a normally Gram-positive only antibiotic to create a potent and targeted Gram-negative antibiotic using a bacterial iron transport based sideromycin Trojan Horse strategy.

  5. Structure-activity relationships and molecular docking studies of chromene and chromene based azo chromophores: A novel series of potent antimicrobial and anticancer agents.

    PubMed

    Afifi, Tarek H; Okasha, Rawda M; Ahmed, Hany E A; Ilaš, Janez; Saleh, Tarek; Abd-El-Aziz, Alaa S

    2017-01-01

    The design of novel materials with significant biological properties is a main target in drug design research. Chromene compounds represent an interesting medicinal scaffold in drug replacement systems. This report illustrates a successful synthesis and characterization of two novel series of chromene compounds using multi-component reactions. The synthesis of the first example of azo chromophores containing chromene moieties has also been established using the same methodology. The antimicrobial activity of the new molecules has been tested against seven human pathogens including two Gm+ve, two Gm-ve bacteria, and four fungi, and the results of the inhibition zones with minimum inhibitory concentrations were reported as compared to reference drugs. All the designed compounds showed significant potent antimicrobial activities, among of them, four potent compounds 4b, 4c, 13e, and 13i showed promising MIC from 0.007 to 3.9 µg/mL. In addition, antiproliferative analysis against three target cell lines was examined for the novel compounds. Compounds 4a, 4b, 4c, and 7c possessed significant antiproliferative activity against three cell lines with an IC50 of 0.3 to 2 µg/mL. Apoptotic analysis was performed for the most potent compounds via caspase enzyme activity assays as a potential mechanism for their antiproliferative effects. Finally, the computational 2D QSAR and docking simulations were accomplished for structure-activity relationship analyses.

  6. Structure-activity relationships and molecular docking studies of chromene and chromene based azo chromophores: A novel series of potent antimicrobial and anticancer agents

    PubMed Central

    Afifi, Tarek H.; Okasha, Rawda M.; Ahmed, Hany E.A.; Ilaš, Janez; Saleh, Tarek; Abd-El-Aziz, Alaa S.

    2017-01-01

    The design of novel materials with significant biological properties is a main target in drug design research. Chromene compounds represent an interesting medicinal scaffold in drug replacement systems. This report illustrates a successful synthesis and characterization of two novel series of chromene compounds using multi-component reactions. The synthesis of the first example of azo chromophores containing chromene moieties has also been established using the same methodology. The antimicrobial activity of the new molecules has been tested against seven human pathogens including two Gm+ve, two Gm-ve bacteria, and four fungi, and the results of the inhibition zones with minimum inhibitory concentrations were reported as compared to reference drugs. All the designed compounds showed significant potent antimicrobial activities, among of them, four potent compounds 4b, 4c, 13e, and 13i showed promising MIC from 0.007 to 3.9 µg/mL. In addition, antiproliferative analysis against three target cell lines was examined for the novel compounds. Compounds 4a, 4b, 4c, and 7c possessed significant antiproliferative activity against three cell lines with an IC50 of 0.3 to 2 µg/mL. Apoptotic analysis was performed for the most potent compounds via caspase enzyme activity assays as a potential mechanism for their antiproliferative effects. Finally, the computational 2D QSAR and docking simulations were accomplished for structure-activity relationship analyses. PMID:28828001

  7. EBI-907, a novel BRAFV600E inhibitor, has potent oral anti-tumor activity and a broad kinase selectivity profile

    PubMed Central

    Zhang, Jiayin; Lu, Biao; Liu, Dong; Shen, Ru; Yan, Yinfa; Yang, Liuqing; Zhang, Minsheng; Zhang, Lei; Cao, Guoqing; Cao, Hu; Fu, Beibei; Gong, Aishen; Sun, Qiming; Wan, Hong; Zhang, Lianshan; Tao, Weikang; Cao, Jingsong

    2016-01-01

    abstract The oncogenic mutation of BRAFV600E has been found in approximately 8% of all human cancers, including more than 60% of melanoma and 10% of colorectal cancers. The clinical proof of concept in treating BRAFV600E-driving melanoma patients with the BRAF inhibitors has been well established. We have sought to identify and develop novel BRAFV600E inhibitors with more favorable profiles. Our chemistry effort has led to the discovery of EBI-907 as a novel BRAFV600E inhibitor with potent anti-tumor activity in vitro and in vivo. In a LanthaScreen BRAFV600E kinase assay, EBI-907 showed an IC50 of 4.8 nM, which is >10 -fold more potent than Vemurafenib (IC50 = 58.5 nM). In addition, EBI-907 showed a broader kinase selectivity profile, with potent activity against a number of important oncogenic kinases including FGFR1-3, RET, c-Kit, and PDGFRb. Concomitant with such properties, EBI-907 exhibits potent and selective cytotoxicity against a broader range of BRAFV600E-dependent cell lines including certain colorectal cancer cell lines with innate resistance to Vemurafenib. In BRAFV600E-dependent human Colo-205 and A375 tumor xenograft mouse models, EBI-907 caused a marked tumor regression in a dose-dependent manner, with superior efficacy to Vemurafenib. Our results also showed that combination with EGFR or MEK inhibitor enhanced the potency of EBI-907 in cell lines with innate or acquired resistance to BRAF inhibition alone. Our findings present EBI-907 as a potent and promising BRAF inhibitor, which might be useful in broader indications. PMID:26810733

  8. Structural Sweet Spot for A1 Adenosine Receptor Activation by Truncated (N)- Methanocarba Nucleosides: Receptor Docking and Potent Anticonvulsant Activity

    PubMed Central

    Tosh, Dilip K.; Paoletta, Silvia; Deflorian, Francesca; Phan, Khai; Moss, Steven M.; Gao, Zhan-Guo; Jiang, Xiaohui; Jacobson, Kenneth A.

    2012-01-01

    A1 adenosine receptor (AR) agonists display antiischemic and antiepileptic neuroprotective activity, but peripheral cardiovascular side effects impeded their development. SAR study of N6-cycloalkylmethyl 4′-truncated (N)-methanocarba-adenosines identified 10 (MRS5474, N6-dicyclopropylmethyl, Ki 47.9 nM) as a moderately A1AR-selective full agonist. Two stereochemically defined N6-methynyl group substituents displayed narrow SAR; larger than cyclobutyl greatly reduced AR affinity, and larger or smaller than cyclopropyl reduced A1AR selectivity. Nucleoside docking to A1AR homology model characterized distinct hydrophobic cyclopropyl subpockets, the larger “A” forming contacts with Thr270 (7.35), Tyr271 (7.36), Ile274 (7.39) and carbon chains of glutamates (EL2), and smaller subpocket “B” between TM6 and TM7. 10 suppressed minimal clonic seizures (6 Hz mouse model) without typical rotarod impairment of A1AR agonists. Truncated nucleosides, an appealing preclinical approach, have more drug-like physicochemical properties than other A1AR agonists. Thus, we identified highly restricted regions for substitution around N6 suitable for an A1AR agonist with anticonvulsant activity. PMID:22921089

  9. Discovery of benzoylisoindolines as a novel class of potent, selective and orally active GlyT1 inhibitors.

    PubMed

    Pinard, Emmanuel; Alberati, Daniela; Bender, Markus; Borroni, Edilio; Brom, Virginie; Burner, Serge; Fischer, Holger; Hainzl, Dominik; Halm, Remy; Hauser, Nicole; Jolidon, Synèse; Lengyel, Judith; Marty, Hans-Peter; Meyer, Thierry; Moreau, Jean-Luc; Mory, Roland; Narquizian, Robert; Norcross, Roger D; Schmid, Philipp; Wermuth, Roger; Zimmerli, Daniel

    2010-12-01

    Benzoylisoindolines were discovered as a novel structural class of GlyT1 inhibitors. SAR studies and subsequent lead optimization efforts focused primarily on addressing hERG liability and on improving in vivo efficacy resulted in the identification of potent GlyT1 inhibitors displaying excellent selectivity and in vivo PD and PK profiles.

  10. Structural definition of a potent macrophage activating factor derived from vitamin D3-binding protein with adjuvant activity for antibody production.

    PubMed

    Yamamoto, N

    1996-10-01

    Incubation of human vitamin D3-binding protein (Gc protein), with a mixture of immobilized beta-galactosidase and sialidase, efficiently generated a potent macrophage activating factor, a protein with N-acetylgalactosamine as the remaining sugar. Stepwise incubation of Gc protein with immobilized beta-galactosidase and sialidase, and isolation of the intermediates with immobilized lectins, revealed that either sequence of hydrolysis of Gc glycoprotein by these glycosidases yields the macrophage-activating factor, implying that Gc protein carries a trisaccharide composed of N-acetylgalactosamine and dibranched galactose and sialic acid termini. A 3 hr incubation of mouse peritoneal macrophages with picomolar amounts of the enzymatically generated macrophage-activating factor (GcMAF) resulted in a greatly enhanced phagocytic activity. Administration of a minute amount (10-50 pg/mouse) of GcMAF resulted in a seven- to nine-fold enhanced phagocytic activity of macrophages. Injection of sheep red blood cells (SRBC) along with GcMAF into mice produced a large number of anti-SRBC antibody secreting splenic cells in 2-4 days.

  11. Leiodermatolide, a novel marine natural product, has potent cytotoxic and antimitotic activity against cancer cells, appears to affect microtubule dynamics, and exhibits antitumor activity.

    PubMed

    Guzmán, Esther A; Xu, Qunli; Pitts, Tara P; Mitsuhashi, Kaoru Ogawa; Baker, Cheryl; Linley, Patricia A; Oestreicher, Judy; Tendyke, Karen; Winder, Priscilla L; Suh, Edward M; Wright, Amy E

    2016-11-01

    Pancreatic cancer, the fourth leading cause of cancer death in the United States, has a negative prognosis because metastasis occurs before symptoms manifest. Leiodermatolide, a polyketide macrolide with antimitotic activity isolated from a deep water sponge of the genus Leiodermatium, exhibits potent and selective cytotoxicity toward the pancreatic cancer cell lines AsPC-1, PANC-1, BxPC-3, and MIA PaCa-2, and potent cytotoxicity against skin, breast and colon cancer cell lines. Induction of apoptosis by leiodermatolide was confirmed in the AsPC-1, BxPC-3 and MIA PaCa-2 cells. Leiodermatolide induces cell cycle arrest but has no effects on in vitro polymerization or depolymerization of tubulin alone, while it enhances polymerization of tubulin containing microtubule associated proteins (MAPs). Observations through confocal microscopy show that leiodermatolide, at low concentrations, causes minimal effects on polymerization or depolymerization of the microtubule network in interphase cells, but disruption of spindle formation in mitotic cells. At higher concentrations, depolymerization of the microtubule network is observed. Visualization of the growing microtubule in HeLa cells expressing GFP-tagged plus end binding protein EB-1 showed that leiodermatolide stopped the polymerization of tubulin. These results suggest that leiodermatolide may affect tubulin dynamics without directly interacting with tubulin and hint at a unique mechanism of action. In a mouse model of metastatic