Oxytocic effects of the water extract of Musanga cecropioides R. Brown (Moraceae) stem bark

Musanga cecropioides (Umbrella tree) is one of the medicinal plants used in tropical parts of Africa for its oxytocic, hypotensive and antidiabetic activities. This work examined the effect of the water extractof the stem bark on rat uterus pre-treated with 1 mg/kg stilboesterol for 24 h. The effects of oxytocin-a uterine contraction agonist, antagonists like atropine (1-2 mg) and salbutamol (2 ìg) on the uterinecontractile effect of the water extract as well as its acute toxic effect were investigated. The water extract of M. cecropioides produced a dose related increase in the force of uterine contraction. An equivalent force of uterine contraction of 1.10 ± 0.15 g produced by 12.5 mg of the extract wasincreased to 2.53 ± 0.6 g when 1600 mg of the extract was administered. Oxytocin at 0.08 i.u. was observed to elicit a similar force of contraction with 400 mg of the water extract. The drug was observed to potentiate the uterine contractile activity of the extract while pre-treating the tissue with either atropine or salbutamol before administering the water extract showed the inhibitory effects of the drugs on the activity of the extract. The inhibition effect showed by atropine suggests the probable stimulation of the muscarinic receptors of the uterus by the extract. Between doses of 1-4 g/kg, the water extract of M. cecropioides was observed to be well tolerated in mice as no obvious signs of toxicity were observed on the animal