In vitro evaluation of antiasthmatic activity of ethanol leaf extract of Guiera senegalensis j. F. GMEL (Combretaceae)

Guiera senegalensis is a medicinal plant that is widely used in West Africa against many illnesses. In this work, the antiasthmatic properties of ethanol leaf extract of the G. senegalensis were evaluated by using various in vitro animal models. In vitro models like isolated guinea pig tracheal chain preparation, isolated guinea pig ileum and rabbit jejunum preparations were studied to evaluate possible mechanism by which extract shows relaxant activity. The preliminary phytochemical screening of the extract revealed the presence of alkaloids, anthraquinones, flavonoids, saponins and tannins. The study showed that the extract contained phytochemicals such as flavonoids, alkaloids, steroids, tannins and saponins. Isolated tracheal smooth muscles contractions induced by histamine was significantly (p<0.01) reduced by the extract, so also that induced by acetylcholine at concentrations of 4 and 8 mg/ml. The findings were similar to that of 0.4 µg/ml isoprenaline. Guinea pig and rabbit jejunum contractions induced by histamine and acetylcholine were significantly (p<0.01) reduced by the extract. These observed effects can be attributed to the presence of phytochemicals such as flavonoids, alkaloids and steroids in the extract. The results of these studies indicated ethanol extract of G. senegalensis possess antiasthmatic activity. Key words: Antiasthmatic activity, bronchoconstriction, Guiera senegalensis, guinea pig ileum.