Abortifacient Potential of Aqueous Extract of Senna alata Leaves in Rats

ObjectiveTo study the abortifacient activity of aqueous extract of Senna alata leaves in female Wistar rats.MethodsPregnant rats weighing 143.65 ± 13.11 g were completely randomized into 5 groups (A-E). Rats in group A (negative control) were orally administered, once daily with 0.5 ml of distilled water on days 10-18 post-coitum while those in groups B, C, D, and E were treated exactly like the negative control except they received the same volume containing 2.85 mg/kg body weight of mifepristone (group B, reference drug), 250, 500 and 1 000 mg/kg body weight of the extract respectively (groups C-E).ResultsPhytochemical screening of the extract showed positive results for saponins (1.22%), flavonoids (1.06%), cardiac glycosides (0.20%), cardenolides and dienolides (0.18%), phenolics (0.44%) and alkaloids (0.52%). Respiratory distress, salivation, diarrhoea, changes in the appearance of hair as well as maternal mortality were not observed at any time during the exposure period except in the mifepristone-treated animals where there was episode of diarrhoea and tiredness. The extract significantly reduced (P<0.05) the number of life foetus, weight and survival ratio of the foetus, numbers of implantations and Corpora lutea, implantation index, progesterone, prolactin, estradiol, follicle stimulating and luteinizing hormones whereas the number of dead foetus, number and percentage of rats that aborted, percentage vaginal opening, resorption index, pre-and post-implantation losses increased significantly. In addition, mifepristone-treated animals produced resorption index that compared well with the distilled water control. There was also no dead or life foetus and serum progesterone concentration was increased in the animals treated with mifepristone. All cases of abortion were accompanied with vaginal bleeding. Although, the final weight of the rats increased significantly, the feed and water intake were not significantly altered in all the treatment groups. The weight of the uterus, uterine-body weight ratio, length of the right uterus horn and uterine cholesterol decreased significantly in all the treatment groups. The uterine alkaline phosphatase activity and glucose concentration increased in only the extract-treated animals whereas mifepristone decreased the uterine alkaline phosphatase activity and glucose content of the animals.ConclusionThis study has provided evidence to the age-long claim of S. alata leaves in “washing the uterus”. The abortifacient properties were most pronounced at 500 and 1 000 mg/kg body weight of the extract and were similar to the animals treated with 2.85 mg/kg body weight of mifepristone. Hormonal influence, changes in implantation site, estrogenicity and uterogenicity are suggested as possible mechanism of abortifacient activity of aqueous extract of S. alata leaves. Overall, the extract may be used as an abortifacient especially at 500 and 1 000 mg/kg body weight and therefore not safe for consumption as oral remedy during pregnancy.