Pro-inflammatory cytokines and nitric oxide inhibitory constituents from Cassia occidentalis roots

The anti-inflammatory and cytotoxic activity of thirty-six extracts of nine Indian medicinal plants were determined by measuring the inhibition of production of nitric oxide (NO), interleukin 1beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha) in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Their cytotoxic activity against macrophages was determined by MTT assay. The ethyl acetate (EtOAc) extract of Cassia occidentalis L. (roots) (IC50 = 21.3 to 43.1 microg/mL) and Mimosa pudica (whole plant) (1C50= 31.7 to 47.2 microg/mL) and the dichloromethane (DCM) extract of Leucas cephalotes (whole plant) (IC50 = 46.8 to 49.3 microg/mL) exhibited significant anti-inflammatory activity by in vitro inhibition of the production of TNF-alpha, IL-1beta and NO in LPS stimulated RAW 264.7 cells. Furthermore, the five compounds isolated from the ethyl acetate extract of Cassia occidentalis roots were found to suppress LPS-induced IL-1beta, TNF-alpha and NO production in a concentration-dependent manner in these cells at 1C50 values ranging from 22.5 to 97.4 microM. Emodin and chrysophanol were also found active in inhibiting pro-inflammatory cytokines in vivo. These findings justify an ethnopharmacological use of C occidentalis roots as an effective herbal remedy for the treatment and prevention of inflammation and associated ailments.