Anti-inflammatory and gastromucosal protective effects of Calotropis procera (Asclepiadaceae) stem bark.

This study was aimed at evaluating the anti-inflammatory and gastromucosal protective effect of chloroform extract (CH) and hydroalcoholic extract (HE) of the stem bark of Calotropis procera obtained successively by cold maceration. The anti-inflammatory effect of the CH and HE extracts of the stem bark of Calotropis procera against carrageenan-induced paw oedema and also its gastromucosal protective effect has been studied by using two acute models: aspirin (100 mg/kg, p.o.) and ethanol (96%) in albino rats. CH and HE extracts showed significant anti-inflammatory activity at 200 and 400 mg/kg, while CH extract at 400 mg/kg was also found to have a significant gastromucosal protective effect. As part of investigations to obtain compounds with anti-inflammatory and gastromucosal protective effects in this work, a bioassay was carried out with fractions obtained from the CH extract with n-hexane (NF1), 1-butanol (BF1), ethyl acetate (EF1) and chloroform (CF1). The HE extract of the stem bark was fractionated with n-hexane (NF2), 1-butanol (BF2), ethyl acetate (EF2), chloroform (CF2) and water (WF2). The fractions were evaluated for their anti-inflammatory and gastromucosal protective effects. Fractions NF1, CF1, BF2 and EF2 (20 mg/kg) showed significant anti-inflammatory activity, while NF1 and BF2 (20 mg/kg) also showed gastromucosal protective effects. The results obtained for gastromucosal protective effects were also well supported by histopathological examination of the open excised rat stomach.