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Strong Inhibitory Activities (strong + inhibitory_activity)
Selected AbstractsAnticandidal low molecular compounds from higher plants with special reference to compounds from essential oils,MEDICINAL RESEARCH REVIEWS, Issue 2 2006A. Pauli Abstract The most active low molecular weight compounds from higher plants against Candida species are compiled from a database of antimicrobials (Amicbase) to find out new hints on their mechanism of action. The selected compounds possess strong inhibitory activities in vitro against Candida species either in the agar diffusion test, bioautography, agar dilution test, serial dilution test, or activity in the vapour phase. The test conditions are listed thoroughly and aspects of the different methods and recent developments in the testing of anticandidal drugs are discussed. The anticandidal spectra of drugs, antiseptics, and disinfectants licensed on the major markets are given for comparision of activities with compounds from natural sources. So far known mechanisms of action are described and some new structure,activity relationships are deduced from relationships between biological activities and chemical and physical parameters. Main specific targets of natural anticandidals are the ergosterol pathway, respiratory chain, and chitin biosynthesis. © 2005 Wiley Periodicals, Inc. Med Res Rev [source] In vitro anti-adhesive activity of green tea extract against pathogen adhesionPHYTOTHERAPY RESEARCH, Issue 4 2009Ji-Hye Lee Abstract Camellia sinensis polysaccharide has been reported to possess anti-adhesive activity against pathogens. The present study was designed to investigate whether hot water extracts obtained from green tea leaves might inhibit pathogen adhesion to human or mouse cell lines. Green tea extract-4 (CSI-4) with the maximum yield of 4% (w/v) is composed of a major proportion of carbohydrates containing 40% uronic acids, but lack of catechins. It showed strong inhibitory activities against hemagglutination mediated by pathogens Helicobacter pylori, Propionibacterium acnes and Staphylococcus aureus with the minimum inhibitory concentrations of 0.01-0.5 mg/mL. CSI-4 further demonstrated an inhibitory effect on the adhesion of these pathogens to host cell lines with the IC50 values (50% inhibition of adhesion) of 0.14,2.3 mg/mL. It exhibited the highest activity against P. acnes, but no inhibitory effects were observed against Lactobacillus acidophilus, Bifidobacterium bifidum, Escherichia coli, or Staphylococcus epidermidis. Our results suggest that CSI-4 may exert a selective anti-adhesive effect against certain pathogenic bacteria with no adverse effects against beneficial or commensal bacteria. Copyright © 2008 John Wiley & Sons, Ltd. [source] DNA Topoisomerase I Inhibitory Alkaloids from Corydalis saxicolaCHEMISTRY & BIODIVERSITY, Issue 7 2008Xuanxuan Cheng Abstract Chemical studies of the Chinese herb Corydalis saxicolaBunting led to the isolation and identification of 14 alkaloids, 1,14. Seven of these compounds, 4,9 and 11, were obtained from this plant for the first time. Feruloylagmatine (7) is the first guanidine-type alkaloid to be identified in the family Papaveraceae and in dicotyledonous plants. All of the isolated compounds were assayed for inhibitory activity against human DNA topoisomerase I. A DNA cleavage assay demonstrated that these alkaloids specifically inhibit topoisomerase through stabilization of the enzyme,DNA complex. Among the isolated alkaloids, (,)-pallidine (8) and (,)-scoulerine (11) showed strong inhibitory activities toward topoisomerase I that were comparable to camptothecin, a typical topoisomerase I inhibitor. A preliminary structure,activity relationship study suggested that the quaternary ammonium ion might play an important role in topoisomerase I inhibition by the isoquinoline alkaloids. These data indicated that DNA topoisomerase I inhibition represents probably one of the anticarcinogenic mechanisms of C. saxicola. [source] 8-Methyldecan-2-yl acetate inhibits response to the pheromone in the western corn rootworm Diabrotica v. virgiferaJOURNAL OF APPLIED ENTOMOLOGY, Issue 5 2010M. Tóth Abstract Compounds that are structurally closely related to the western corn rootworm (WCR) (Diabrotica v. virgifera, Coleoptera: Chrysomelidae) pheromone were prepared and screened for biological activity in the field, presented alone or in combination with the pheromone 8-methyldecan-2-yl propanoate. None of the synthetic compounds showed attraction when presented alone. However, when presented in combination with the pheromone, catches in traps containing 8-methyldecan-2-yl acetate as a second component were dramatically reduced, suggesting strong inhibitory activity for this compound. The addition of the inhibitory acetate to the known floral WCR lure (4-methoxycinnamaldehyde plus indole) did not influence male (or female) catches suggesting that the inhibitor interferes in the perception process of the pheromone and not by exerting repellency per se. To our knowledge, this is the first report on an inhibitor of response to pheromone in WCR. 8-Methyldecan-2-yl acetate has previously been described as a sex attractant of Diabrotica cristata, so its inhibitory activity towards males of WCR may reflect a role in maintaining reproductive isolation between the two taxa. [source] Isolation and partial characterization of a bacteriocin produced by Pediococcus pentosaceus K23-2 isolated from KimchiJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2008M.S. Shin Abstract Aims:, Screening and partial characterization of a bacteriocin produced by Pediococcus pentosaceus K23-2 isolated from Kimchi, a traditional Korean fermented vegetable. Methods and Results:, A total of 1000 lactic acid bacteria were isolated from various Kimchi samples and screened for the production of bacteriocin. Pediocin K23-2, a bacteriocin produced by the Pediococcus pentosaceus K23-2 strain, showed strong inhibitory activity against Listeria monocytogenes. The bacteriocin activity remained unchanged after 15 min of heat treatment at 121°C or exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. The bacteriocin was maximally produced at 37°C, when the pH of the culture broth was maintained at 5·0 during the fermentation, although the optimum pH for growth was 7·0. The molecular weight of the bacteriocin was about 5 kDa according to a tricine SDS-PAGE analysis. Conclusions:,Pediococcus pentosaceus K23-2 isolated from Kimchi produces a bacteriocin, which shares similar characteristics to the Class IIa bacteriocins. The bacteriocin is heat stable and shows wide antimicrobial activity against Gram-positive bacteria, especially L. monocytogenes. Significance and Impact of the Study:, Pediocin K23-2 and pediocin K23-2-producing P. pentosaceus K23-2 could potentially be used in the food and feed industries as natural biopreservatives, and for probiotic application to humans or livestock. [source] Inhibition of nitric oxide synthase inhibitors and lipopolysaccharide induced inducible NOS and cyclooxygenase-2 gene expressions by rutin, quercetin, and quercetin pentaacetate in RAW 264.7 macrophagesJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2001Yen-Chou Chen Abstract Several natural flavonoids have been demonstrated to perform some beneficial biological activities, however, higher-effective concentrations and poor-absorptive efficacy in body of flavonoids blocked their practical applications. In the present study, we provided evidences to demonstrate that flavonoids rutin, quercetin, and its acetylated product quercetin pentaacetate were able to be used with nitric oxide synthase (NOS) inhibitors (N -nitro- L -arginine (NLA) or N -nitro- L -arginine methyl ester (L -NAME)) in treatment of lipopolysaccharide (LPS) induced nitric oxide (NO) and prostaglandin E2 (PGE2) productions, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene expressions in a mouse macrophage cell line (RAW 264.7). The results showed that rutin, quercetin, and quercetin pentaacetate-inhibited LPS-induced NO production in a concentration-dependent manner without obvious cytotoxic effect on cells by MTT assay using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide as an indicator. Decrease of NO production by flavonoids was consistent with the inhibition on LPS-induced iNOS gene expression by western blotting. However, these compounds were unable to block iNOS enzyme activity by direct and indirect measurement on iNOS enzyme activity. Quercetin pentaacetate showed the obvious inhibition on LPS-induced PGE2 production and COX-2 gene expression and the inhibition was not result of suppression on COX-2 enzyme activity. Previous study demonstrated that decrease of NO production by L -arginine analogs effectively stimulated LPS-induced iNOS gene expression, and proposed that stimulatory effects on iNOS protein by NOS inhibitors might be harmful in treating sepsis. In this study, NLA or L -NAME treatment stimulated significantly on LPS-induced iNOS (but not COX-2) protein in RAW 264.7 cells which was inhibited by these three compounds. Quercetin pentaacetate, but not quercetin and rutin, showed the strong inhibitory activity on PGE2 production and COX-2 protein expression in NLA/LPS or L -NAME/LPS co-treated RAW 264.7 cells. These results indicated that combinatorial treatment of L -arginine analogs and flavonoid derivates, such as quercetin pentaacetate, effectively inhibited LPS-induced NO and PGE2 productions, at the same time, inhibited enhanced expressions of iNOS and COX-2 genes. J. Cell. Biochem. 82: 537,548, 2001. © 2001 Wiley-Liss, Inc. [source] | |||||||||||||