Herbal contraceptives: Evaluation of antifertility potential of Hibiscus rosa-sinensis (Linn.) Original paper

What was reviewed?

This review article examined the antifertility potential of Hibiscus rosa-sinensis Linn., a plant widely recognized in traditional medicine, with a focus on its possible use as a herbal contraceptive. It synthesized evidence from pharmacological studies, toxicological evaluations, and ethnomedicinal reports assessing the plant’s effects on female reproductive physiology. The review explored the mechanisms by which H. rosa-sinensis extracts influence ovarian function, estrous cycle regulation, implantation, and spermatogenesis, emphasizing the potential for the development of safe and reversible herbal contraceptives.

Who was reviewed?

The review incorporated preclinical data from various animal models, predominantly female albino rats and mice, to investigate the antifertility effects of different H. rosa-sinensis plant parts, including flowers, leaves, roots, and seeds. It covered studies evaluating estrogenic, antiovulatory, antiimplantation, and abortifacient activities through the administration of various extracts (benzene, ethanolic, aqueous) at different doses. Some studies also assessed effects on male reproductive parameters such as spermatogenesis. Human clinical data were limited, but traditional and ethnopharmacological uses of the plant in India and neighboring regions were considered.

Most important findings

The review found consistent evidence that H. rosa-sinensis flower extracts exert significant antifertility effects mediated through multiple pathways. The benzene extract of flowers disrupted estrous cycles by prolonging estrus and metestrus phases, increasing atretic follicles, and preventing the formation of corpora lutea, indicating antiovulatory activity. Estrogenic effects were demonstrated by increased uterine weight and premature vaginal opening in immature mice. Antiimplantation effects were confirmed by failure of blastocyst implantation and biochemical alterations in the endometrium, including changes in oxidative stress markers. Additionally, extracts showed abortifacient activity through progesterone suppression and luteolysis. In males, extracts induced reversible spermatogenic damage and reduced accessory sex organ weights. Importantly, the antifertility effects were dose-dependent and reversible upon discontinuation. Phytochemical analyses identified flavonoids, alkaloids, steroids, and other bioactive compounds as probable mediators. Despite promising pharmacological effects, the review emphasized variability in extract preparation and a lack of standardized formulations.

Key implications

This review highlights Hibiscus rosa-sinensis as a promising source for the development of herbal contraceptives, offering advantages such as reversibility and reduced side effects compared to synthetic drugs. The multifaceted antifertility mechanisms targeting ovarian function, implantation, and male fertility provide a broad basis for contraceptive applications. However, substantial gaps remain, including the need for rigorous toxicological evaluations, standardized extraction methods, clinical trials in humans, and a detailed understanding of molecular targets. Harnessing H. rosa-sinensis could contribute to safer, cost-effective contraceptive options, particularly in settings with limited access to modern pharmaceuticals, but careful research is needed to ensure efficacy, safety, and dosage consistency.