Antiinflammatory effects and chemical constituents of Veronicastrum axillare.

Our study aims to ascertain the antiinflammatory activity of Veronicastrum axillare and characterize the bioactive constituents. Antiinflammatory activity of the total extract and different fractions from V. axillare was investigated by employing the xylene-induced mouse ear edema model. As a result, the ethyl acetate (EtOAc) fraction showed the highest antiinflammatory activity in vivo. From the EtOAc fraction and the inactive dichloromethane fraction, a total of five new compounds, axillasides A-C and axillactones A and B, together with four known compounds, procumboside A, buergeriside C1 , indole-3-carboxylic acid and apigenin, were isolated and identified. Their structures were elucidated on the basis of spectroscopic analysis and by comparison of their nuclear magnetic resonance data with those reported in the literature. Procumboside A, a major constituent in EtOAc fraction, showed significant antiinflammatory activity in vivo. Further studies revealed that procumboside A was a potent COX-2 inhibitor, significantly reducing the COX-2 protein level in lipopolysaccharide-stimulated RAW 264.7 macrophages.