Anti-oxidative and Anti-inflammatory Effects of Flavonoids from the Silk of Zea mays Linn

Activity-guided isolation of the silk of Zea mays Linn (ZMS) yielded three flavonoids, chrysoeriol-6-C-beta-boivinopyranosyl-7-O-beta-glucopyranoside (1), chrysoeriol (2) and luteolin (3). Anti-oxidative activity was measured using the 2,2-diphenyl-1-picryl-hydrazyl and superoxide dismutase-like superoxide anion (generated by xanthine oxidase/hypoxanthine) scavenging assays. Anti-inflammatory activity was confined by quantifying the protein and mRNA levels of inducible nitric oxide synthase and cyclooxygenase-2 in lipopolysaccharide-stimulated HaCaT cells using western blotting and real-time polymerase chain reaction. The results showed that luteolin 3 exhibited potent 2,2-diphenyl-1-picryl-hydrazyl (IC50 = 18.31 +/- 1.29 mu M) and superoxide dismutase-like superoxide anion scavenging activity (IC50 = 1.47 +/- 0.14 mu M) and dose-dependently inhibited the protein expression of inducible nitric oxide synthase and cyclooxygenase-2 as well as their mRNA levels.