Post-Coital Antifertility Activity of Hibiscus rosa-sinensis Linn. roots Original paper

What was studied?

This original research study investigated the post-coital antifertility and estrogenic activities of the ethanolic extract of Hibiscus rosa-sinensis Linn. roots. The primary aim was to evaluate the extract’s ability to prevent implantation in pregnant rats and to assess its effects on uterine weight, histology, and vaginal cytology, which are indicative of estrogenic activity. The study focused on exploring the potential contraceptive effects of the root extract, an area less studied compared to other parts of the plant, like flowers or leaves.

Who was studied?

The study utilized female albino Wistar rats for antifertility testing and immature ovariectomized female rats for estrogenic activity assessment. Animals were maintained under standard laboratory conditions, and only rats with regular estrous cycles were selected for the experiments. For toxicity evaluation, adult albino mice of both sexes were used. The post-coital antifertility testing involved treating pregnant rats with oral doses of 200 and 400 mg/kg body weight of the ethanolic root extract from day 1 to day 7 of pregnancy, followed by laparotomy to assess implantation on day 10.

Most important findings

The study demonstrated potent post-coital antifertility activity, with the 400 mg/kg dose producing 100% inhibition of implantation, while the 200 mg/kg dose showed partial inhibition (16.66%). No toxic effects or weight changes were observed, and the antifertility effect was reversible as treated rats conceived normally after discontinuation. Estrogenic activity was evident as the 400 mg/kg extract significantly increased uterine weight, uterine diameter, and endometrial thickness compared to controls. Histological analysis revealed uterine inflation, increased epithelial cell proliferation, and fluid accumulation resembling the proestrous/estrous state. Vaginal smears indicated increased cornification, consistent with estrogenic stimulation. Co-administration of the extract with ethinyl estradiol further enhanced these parameters, indicating no antiestrogenic effect. The findings suggest the extract’s antifertility action is likely mediated by estrogenic mechanisms, causing anti-implantation effects.

Key implications

This study supports the traditional use of Hibiscus rosa-sinensis roots as a potential herbal contraceptive through anti-implantation and estrogenic effects. The extract’s strong and reversible inhibition of implantation with no overt toxicity indicates promise for developing safe, plant-based contraceptive agents. These findings encourage further research into isolation of active phytochemicals, mechanism elucidation, and evaluation of clinical applicability. Given the current challenges with synthetic contraceptives, including side effects and discontinuation, such herbal alternatives could provide safer, more acceptable fertility regulation options, especially in resource-limited settings.