The uterotonic screening of calyx extracts of Hibiscus sabdariffa on estrogenized isolated Uterus of Wister strain albino rats

The claim of the use of orally consumed concentrated Hibiscus sabdariffa calyx preparation for the purpose of abortion in view of its widely uses as a beverage in the present period of economic hardship where it is a preferred beverage due to its affordability, naturalness and for its numerous medicinal properties has posed another element of concern to the female folks. This study was aimed to screen extracts of H. sabdariffa calyx of its acclaimed uterotonic activity. Contractile responses of estrogenized isolated rat uterus using various volumes (0.1, 0.2, 0.4, 0.6, 0.8, 1.0,1.6 ml) were established with oxytocin (1x10-4 g/ml), ergometrine (1x10-4 g/ml), misoprostol (1x10-4 g/ml), Acetylcholine (1x10-3 g/ml) and five different extracts of H. sabdariffa - ethanol (2.0x10-3 g/ml), methanol (2.0x10-3 g/ml), acetone (2.0x10-3 g/ml), cold water (2.0x10-3 g/ml) and hot water (2.0x10-3 g/ml). After these, nifedipine, acetylcholine and salbutamol were used to challenge the maximal responses of the isolated uterine tissue to oxytocin, acetylcholine and the cold aqueous extract of H. sabdariffa (CWEHs). The CWEHs was equally potent at inducing contraction activity compared to the standard drugs. This study further shows reduction in the amplitude of contraction produced by CWEHs in the presence of Promethazine (1×10−6 g/ml) and Nifedipine (1×10−6 g/ml). The blockade is more pronounced in promethazine compared to Nifedipine. Aqueous extract of Hibiscus sabdariffa calyx possess uterotonic activity on estrogenized isolated rat uterine muscle with mechanism of action related to histamine receptors and contraction of the myometrial cells as the was antagonized by promethazine and Nifedipine. This could be a justification for its alarming use as an abortifacient.