Pharmacological Effects of a Fraction of the Methanolic Extract of Prosopis africana Fruit (Guill and Perr ) Taub

Abstract

The pharmacological effects of some fractions of the Prosopis africana fruits (MEPAF) were investigated. The fractions were obtained by subjecting the MEPAF to accelerated gradient column and Thin-Layer chromatography (TLC). Nine (9) fractions were obtained based on their retention factor (R ). One of the fractions, f fraction G was selected for further studies based on its better local anaesthetic activity using the guinea pig wheal test. The MEPAF did not show any measurable effect on the ocular reflexes and isolated frog rectus abdominis muscles but showed both concentration and timedependent inhibitions of the intrinsic peristaltic contractions of the rabbit jejunum. It also induced concentration-dependent inhibitions of the contractions induced by acetylcholine (2.5 ìg/ml) on isolated rabbit
jejunum. These inhibitions are thought to be antimuscarinic or atropine-like, since the contractions of the jejunal segment is believed to be through muscarinic receptors and could be blocked by atropine and related compounds . Phytochemical spot tests of the fraction G
revealed the presence of alkaloids, carbohydrates, saponins, tannins, sterol, terpenes but not flavonoids, polyuronoids and reducing sugar. These findings give credence to the folkloric use of Propsopis africana in the treatment of body pain, toothache and dysentery.