Résumé
Ipomoea imperati (Convolvulaceae) lives on the sandy shores of the Brazilian coast and in other areas of the world. The anti-inflammatory activity of a methanol-water extract of the leaves of I. imperati was investigated in experimental models of acute and subchronic inflammation. Topical application of the extract (10 mg/ear) inhibited mouse ear edema induced by croton oil (89.0 ± 1.3 percent by the lipid fraction with an IC50 of 3.97 mg/ear and 57.0 ± 1.3 percent by the aqueous fraction with an IC50 of 3.5 mg/ear) and arachidonic acid (42.0 ± 2.0 percent with an IC50 of 4.98 mg/ear and 31.0 ± 2.0 percent with an IC50 of 4.72 mg/ear). Phospholipase A2, purified from Apis mellifera bee venom, was also inhibited by the extract (5.0 mg/ml lipid and aqueous fraction) in vitro in a dose-dependent manner (85 percent by the lipid fraction with an IC50 of 3.22 mg/ml and 25 percent by the aqueous fraction with an IC50 of 3.43 mg/ml). The methanol-water extract of I. imperati (1000 mg/kg) administered by the oral route also inhibited the formation of cotton pellet-induced granulomas (73.2 ± 1.2 percent by the lipid fraction and 56.14 ± 2.7 percent by the aqueous fraction) and did not cause gastric mucosal lesions. I. imperati extracts (10 mg/ml) also inhibited in a dose-dependent manner the muscle contractions of guinea pig ileum induced by acetylcholine and histamine (IC50 of 1.60 mg/ml for the lipid fraction and 4.12 mg/ml for the aqueous fraction). These results suggest the use of I. imperati as an anti-inflammatory and antispasmodic agent in traditional medicine