Coumestrol as an Effective Dietary Supplement: Comprehensive Experimental Evidence From In Vitro Studies and Animal Models of Human Disease

Phytoestrogens are plant-derived, non-steroidal polyphenolic compounds that mimic estrogenic activity and have gained considerable attention due to their potential health benefits and risks. Among them, coumestrol, a member of the coumestan class, exhibits strong affinity for estrogen receptors (ERα and ERβ) and demonstrates biological activity comparable to endogenous estrogens, although with lower potency. Emerging evidence suggests that dietary phytoestrogens may offer protective effects against estrogen-related disorders, including menopausal symptoms, osteoporosis, cardiovascular diseases, and certain cancers; however, concerns remain regarding their safety at higher doses, particularly in hormone-sensitive conditions. This study aimed to evaluate the pharmacokinetic profile, metabolic effects, and safety of coumestrol using a randomized controlled preclinical model in Wistar rats. Animals were divided into control, low-, mid-, and high-dose coumestrol groups, along with a positive control. Coumestrol was administered orally, and both acute and repeated-dose (14–90 days) studies were conducted. Pharmacokinetic analysis revealed dose-dependent increases in Cmax and AUC, with Tmax observed within 1–3 hours, indicating rapid absorption and predictable systemic exposure. Biochemical and metabolic assessments demonstrated significant improvements (p < 0.05) in glucose and lipid profiles at low and mid doses, along with reduced oxidative stress and inflammatory markers. However, high-dose exposure resulted in mild elevations in liver enzymes without significant renal toxicity. Overall, coumestrol exhibited beneficial metabolic effects at lower doses with a favorable safety profile, while higher doses necessitate cautious use. In conclusion, coumestrol shows promise as a natural selective estrogen receptor modulator (SERM) with potential therapeutic applications. Nevertheless, further clinical and mechanistic studies are required to establish its long-term safety and efficacy in humans.