Abstract:
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.
