In vitro anti-inflammatory activity of 3-O-methyl-flavones isolated from Siegesbeckia glabrescens

Four flavones, 3,4′-O-dimethylquercetin (1), 3,7-O-dimethylquercetin (2), 3-O-methylquercetin (3) and 3,7,4′-O-trimethylquercetin (4) were isolated as the inhibitors of nitric oxide production in activated microglia (IC50 values: 11.1, 4.2, 3.8, and 25.1 μM, respectively). They suppressed the expression of protein and mRNA of inducible nitric oxide synthase. Furthermore, compounds 2 and 3 showed scavenging activity of peroxynitrite with SC50 values of 1.75 and 0.77 μM, respectively.

Four quercetin derivatives from Siegesbeckia glabrescens inhibited the production of nitric oxide and the expression of iNOS in LPS-activated microglia.Figure optionsDownload as PowerPoint slide