Wogonin, baicalin, and baicalein inhibition of inducible nitric oxide synthase and cyclooxygenase-2 gene expressions induced by nitric oxide synthase inhibitors and lipopolysaccharide11Abbreviations: NO, nitric oxide; iNOS, inducible nitricoxide synthase; COX-2, cyclooxygenase-2; PGE2,prostaglandin E2; MTT,3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, LPS,lipopolysaccharide; NLA, N-nitro-l-arginine; andL-NAME, N-nitro-l-arginine methyl ester.

摘要: We previously reported that oroxylin A, a polyphenolic compound, was potent inhibitor of lipopolysaccharide (LPS)-induced expression inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). In the present study, three A structurally related polyphenols isolated from Chinese herb Huang Qui, namely baicalin, baicalein, wogonin, were examined for their effects on LPS-induced (NO) production iNOS COX-2 gene expressions in RAW 264.7 macrophages. The results indicated these compounds inhibited NO concentration-dependent manner without notable cytotoxic effect cells. decrease parallel with inhibition by expression. However, did not directly affect enzyme activity. addition, but baicalin or prostaglandin E2 (PGE2) affecting Furthermore, N-nitro-L-arginine (NLA) methyl ester (L-NAME) pretreatment enhanced (but COX-2) protein expression, which compounds. Wogonin, similarly PGE2 NLA/LPS L-NAME/LPS-co-treated These co-treatment NOS inhibitors such as wogonin effectively blocks acute and, at same time, inhibits genes.