It was estimated that every year, 536,000 women and girls die as a result of complications during pregnancy and child birth (WHO, 2007). Several medicinal plants, including Alstonia boonei De Wild (Apocynaceae), are used in the traditional settings for beneficial effects during pregnancy to induce labour, remove retained placenta or to manage post-partum haemorrhage. In the present study, the oxytocic effect of A. boonei was investigated. The stem bark of the plant was extracted successively with n-hexane and 95% methanol and the methanol extract further fractionated with chloroform and ethyl acetate. The uterine contractility effect of the extract and fractions was investigated in vitro using isolated uterine segments from pregnant and stilbesterol pre-treated non-pregnant female rats. The segments were exposed to graded bath concentrations (0.5 -100 µg/ml) of the test plant samples and the standard drugs, oxytocin and acetylcholine, and the responses were recorded using a kymograph at 37 ºC. Phytochemical analysis of the extracts and fractions was done by the standard procedures. Results showed that, at lower concentrations, the extracts and fractions contracted the uterine horns of the pregnant rats similar to oxytocin and acetylcholine in a concentration related manner. There was no contraction of the uterus of non-pregnant rats. Phytochemical analysis revealed the presence of terpenes, steroids, flavonoids, saponins and alkaloids. The present study has established the oxytocic activity of A. boonei thus providing the scientific basis for its use in traditional medicine for the induction of labour.
References
World Health Organisation (2007). Maternal mortality in 2005: estimate developed by WHO, UNICEF, UNFPA and the world bank. WHO, Geneva.