Anti-Inflammatory Activity of N-Butanol Extract from Ipomoea stolonifera In Vivo and In Vitro

Ipomoea stolonifera (I. stolonifera) has been used for the treatment of inflammatory diseases including rheumatism and rheumatoid arthritis in Chinese traditional medicine. However, the anti-inflammatory activity of I. stolonifera has not been elucidated. For this reason, the anti-inflammatory activity of n-butanol extract of I. stolonifera (BE-IS) was evaluated in vivo by using acute models (croton oil-induced mouse ear edema, carrageenan-induced rat paw edema, and carrageenan-induced rat pleurisy) and chronic models (cotton pellet-induced rat granuloma, and complete Freund’s adjuvant (CFA)-induced rat arthritis). Results indicated that oral administration of BE-IS significantly attenuated croton oil-induced ear edema, decreased carrageenan-induced paw edema, reduced carrageenan-induced exudates and cellular migration, inhibited cotton pellet-induced granuloma formation and improved CFA-induced arthritis. Preliminary mechanism studies demonstrated that BE-IS decreased the levels of myeloperoxidase (MPO) and malondialdehyde (MDA), increased the activity of anti-oxidant enzyme superoxide dismutase (SOD) in vivo, and reduced the production of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 in lipopolysaccharide-activated RAW264.7 macrophages in vitro. Results obtained in vivo and in vitro demonstrate that BE-IS has considerable anti-inflammatory potential, which provided experimental evidences for the traditional application of Ipomoea stolonifera in inflammatory diseases.