A combined extract of Cinnamomi Ramulus, Anemarrhenae Rhizoma and Alpiniae Officinari Rhizoma suppresses production of nitric oxide by inhibiting NF-kappaB activation in RAW 264.7 cells

An herbal mixture prepared with Cinnamomi Ramulus, Anemarrhenae Rhizoma and Alpiniae Officinari Rhizoma (CAA) is used in oriental medicine for treating several ailments. The purpose of this study was to determine the mechanisms by which CAA elicits an antiinflammatory effect on nitric oxide (NO) production in the mouse macrophage cell line RAW 264.7 cells. The results indicated that lipopolysaccharide (LPS)-induced NO production was inhibited by CAA in a dose-dependent manner. Western blotting and RT-PCR analysis demonstrated that CAA decreased LPS-induced inducible nitric oxide synthase (iNOS) protein and gene expression in RAW 264.7 cells. Furthermore, CAA inhibited the LPS-induced DNA binding activity of nuclear factor-kappa B (NF-kappaB) and this effect was mediated through inhibiting the degradation of inhibitory factor-kappaBalpha (IkappaBalpha). Therefore, the results demonstrate that CAA inhibits LPS-induced production of NO and expression of iNOS by blocking NF-kappaB activation. CAA might be a potential therapeutic candidate for treating inflammatory diseases such as arthritis.