1Department of Biological Sciences, Egerton University 2Department of Biological Sciences, Egerton University 3Department of Veterinary Anatomy and Physiology, University of Nairobi 4Department of Medical Physiology, University of Nairobi
Uterotonics have the ability to contract uterus. Such plants might be useful in augmenting or inducing labour, expelling retained afterbirth and for abortifacient purposes. Limitations associated with conventional treatments have made herbal medicines a feasible alternative for the management of these conditions. The aim of this study was to evaluate the contractile effects of Uvariodendron kirkii extracts on isolated uterine strips of female Wistar rats. Isolated strips of Wistar rats’ uteri were treated with 20, 40, 80 and 160 mg/ml concentrations of Uvariodendron kirkii aqueous extract. The plant extract was also tested against prostaglandin and oxytocin induced uterine contractions. Uvariodendron kirkii extract concentrations (20, 40, 80 and 160 mg/ml) increased the frequency of uterine contraction (16.53, 25.12, 33.48 and 56.39 percentages respectively) compared to the control. The graded extract concentrations caused a significant increase in amplitude (force) of uterine contractions by 2.87, 9.22, 16.37 and 24.32 percentages respectively. The concentrations significantly increased the frequency of oxytocin induced uterine contractions by 6.92; 28.31; 47.06, 58.78 percentages respectively. The graded extract concentrations also significantly increased the amplitude of oxytocin induced uterine contractions by 6.07; 9.40; 15.19 and 23.56 percentages respectively. Uvariodendron kirkii extract concentrations significantly increased the frequency and amplitude of prostaglandin induced contractions. The percentage increase in frequency was 11.44, 8.92, 20.65 and 35.71 at 20, 40, 80 and 160 mg/ml respectively. The mean amplitude of prostaglandin induced uterine contractions also increased (4.75, 3.89, 8.29 and 15.91% at 20. 40, 80 and 160 mg/ml respectively). The extract caused a dose dependent increase in uterine frequency and amplitude of contraction. The findings of this study are useful in generating a novel uterotonic agent that will be useful in augmenting labour or in expelling retained after birth in cattle. More studies at molecular level will further elucidate the plant mechanism of action.