Anti‐Inflammatory Constituents from the Branches of Pourthiaea villosa (Thunb.) Decne

In this study, the extract from Pourthiaea villosa Decne branches was investigated and their anti‐inflammatory constituents were identified. The prepared ethanol extract was fractionated successively to afford n ‐hexane, ethyl acetate ( EtOAc ), n ‐butanol, and aqueous layers. In the examination of the anti‐inflammatory activities, EtOAc layer was observed to have good nitric oxide production inhibitory property in lipopolysaccharide ( LPS )‐stimulated RAW 264.7 cells. Phytochemical studies for EtOAc layer led to isolation of eight constituents such as ursolic acid ( 1 ), arjunolic acid ( 2 ), daucosterol ( 3 ), myricanol ( 4 ), gallic acid ( 5 ), myricetin ( 6 ), myricitrin ( 7 ), and quercitrin ( 8 ). The isolate 4 efficiently inhibited nitric oxide production in a dose‐dependent manner in LPS ‐induced RAW 264.7 cells. The production of inducible nitric oxide synthase ( iNOS ) enzyme protein was decreased by compound 4 , which showed that the observed NO inhibition could be interconnected to down‐expression of iNOS protein. In addition, compound 4 reduced the production of TNF ‐α, IL ‐1β, and IL ‐6 in a concentration‐dependent manner. This study demonstrated that the P. villosa extract containing myricanol ( 4 ) could be considered potential anti‐inflammatory agents in pharmaceutical or cosmetic industries.