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Induced Nitric Oxide (induced + nitric_oxide)
Selected AbstractsInhibition 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] Bis-(3-hydroxyphenyl) diselenide inhibits LPS-stimulated iNOS and COX-2 expression in RAW 264.7 macrophage cells through the NF- kB inactivationJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 4 2009Kyung-Min Shin Abstract Objectives Previously, we reported that diaryl diselenide compounds have strong inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophages. In this study, we investigated the molecular mechanisms underlying NO suppression and prostaglandin E2 (PGE2) production by diaryl diselenide compounds, bis-(2-hydroxyphenyl) diselenide (DSE-A), bis-(3-hydroxyphenyl) diselenide (DSE-B), bis-(4-hydroxyphenyl) diselenide (DSE-C), dipyridyl diselenide (DSE-D) and diphenyl diselenide (DSE-E). Methods The effect of these compounds on NO suppression and PGE2 production was investigated in RAW 264.7 macrophages. Key findings Our data indicate that of the above, DSE-B most potently inhibits NO and PGE2 production, and that it also significantly reduces the releases of tumour necrosis factor (TNF)-,, interleukin(IL)-1, and IL-6. Consistent with these observations, DSE-B also reduced the protein levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), and the mRNA levels of iNOS, COX-2, TNF-,, IL-1, and IL-6. Furthermore, DSE-B inhibited LPS-induced nuclear factor-,B (NF-,B) activation, which was associated with the prevention of the inhibitor ,B-, (I,B-,) degradation and a subsequent reduction in nuclear p65 protein levels. Conclusions Taken together, our data suggest that the anti-inflammatory properties of DSE-B are due to reduction in the expression of iNOS, COX-2, TNF-,, IL-1, and IL-6 through the down-regulation of NF-,B binding activity. [source] Antiinflammatory activities of flavonoids and a triterpene caffeate isolated from Bauhinia variegataPHYTOTHERAPY RESEARCH, Issue 7 2008Yerra Koteswara Rao Abstract In the continuing search for novel antiinflammatory agents, six flavonoids, namely kaempferol (1), ombuin (2), kaempferol 7,4,-dimethyl ether 3- O - , - d -glucopyranoside (3), kaempferol 3- O - , - d -glucopyranoside (4), isorhamnetin 3- O - , - d -glucopyranoside (5) and hesperidin (6), together with one triterpene caffeate, 3, - trans -(3,4-dihydroxycinnamoyloxy)olean-12-en-28-oic acid (7) were isolated from the non-woody aerial parts of Bauhinia variegata. Compounds 1,7 were evaluated as inhibitors of some macrophage functions involved in the inflammatory process. These seven compounds significantly and dose dependently inhibited lipopolysaccharide (LPS) and interferon (IFN)- , induced nitric oxide (NO), and cytokines [tumor necrosis factor (TNF)- , and interleukin (IL)-12]. The concentration causing a 50% inhibition (IC50) of NO, TNF- , and IL-12 production by compounds 1, 2 and 7 was approximately 30, 50 and 10 µM, respectively, while at 50, 200 and 40 µM compounds 3, 4, and 5, 6 showed 15,30% inhibition, respectively. On the other hand, compounds 3 and 7 showed no inhibitory effect, while compounds 1, 4,6 reduced by around 10,30% the synthesis of NO by macrophages, when inducible NO synthase was already expressed with LPS/IFN- , for 24 h. These experimental findings lend pharmacological support to the suggested folkloric uses of the plant B. variegata in the management of inflammatory conditions. Copyright © 2008 John Wiley & Sons, Ltd. [source] Constituents of Asarum sieboldii with Inhibitory Activity on Lipopolysaccharide (LPS)-Induced NO Production in BV-2 Microglial CellsCHEMISTRY & BIODIVERSITY, Issue 2 2008Ah-Reum Han Abstract Bioassay-guided fractionation of the root extract of Asarum sieboldii led to the isolation of the four active compounds (,)-sesamin (1), (2E,4E,8Z,10E)- N -(2-methylpropyl)dodeca-2,4,8,10-tetraenamide (2), kakuol (3), and ,3,4,5-trimethoxytoluene' (=1,2,3-trimethoxy-5-methylbenzene; 4), in terms of inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production. Compounds 1,4 showed potent inhibition of NO production, with IC50 values in the low nanomolar-to-micromolar range. Also isolated were the known compounds methylkakuol (5), ,3,5-dimethoxytoluene', safrole, asaricin, methyleugenol, and (,)-asarinin, which were found to be inactive in the above assay. Among the ten known isolates, compounds 1, 2, and 5 were found for the first time in this plant. [source] | ||||||||||