Anti-inflammatory effect of natural and semi-synthetic phthalides.

This study evaluated the potential anti-inflammatory effects of natural phthalides, isolated from Ligusticum porteri, and of semi-synthetic phthalides. Anti-inflammatory activity was investigated in two mouse models; one with ear edema, induced with 12-O-tetradecanoylphorbol-13-acetate, and the other with paw edema, induced with carrageenan. The effect on the RAW 264.7 stimulated with lipopolysaccharide cells was evaluated and after application of 12-O-tetradecanoylphorbol-13-acetate, the activity of myeloperoxidase was assessed to serve as an index of leukocytes infiltration together with the histological evaluations. We also assessed the inhibition of cyclooxygenases 1 and 2 in vitro. Our results demonstrated that administration of semi-synthetic phthalides significantly inhibited the ear edema induced by 12-O-tetradecanoylphorbol-13-acetate, and reduced the paw edema caused by carrageenan. The anti-inflammatory activity of phthalides could, in part, be explained by the reduction in myeloperoxidase activity and the infiltration of leukocytes. The semi-synthetic phthalides also inhibited the production of oxide nitric in RAW cells.