Plaunol A from Croton stellatopilosus Inhibits Inducible Nitric Oxide Synthase and Cyclooxygenase-2 in Macrophage RAW264.7 Cells

Abstract

A clerodane diterpene (plaunol A) and three flavonoids (vitexin; luteolin-7-O-β-D-glucoside and luteolin-4'-O-glucoside) were isolated from stems and leaves of Croton stellatoliosus Ohba, using series of chromatographic techniques. Evaluation for anti-inflammatory activity in LPS-induced RAW264.7 cells revealed that, only plaunol A exhibited the inhibitory activity on nitric oxide production with the IC50 of 11.69 μM. This was no cytotoxic effect to the cells at a concentration of 100 μM, by MTT assay. Determination of mRNA levels by qRT-PCR, indicated that plaunol A suppressed the expressions of inducible nitric oxide synthase and cyclooxygenase-2 in lipopolysaccharide-induced RAW264.7 cells.