Protective Effects of Eclipta alba Extract in Letrozole-Induced Polycystic Ovary Syndrome in Rats

Background Polycystic ovary syndrome (PCOS) is a complex endocrine-metabolic disorder characterized by hyperandrogenism, reproductive dysfunction, insulin resistance, dyslipidemia, oxidative stress, and chronic low-grade inflammation. Eclipta alba (L.) Hassk. (syn. Eclipta prostrata (L.) L.),.; Asteraceae), known as Mo Han Lian (墨旱莲) and used as Ecliptae Herba in Traditional Chinese Medicine (TCM), is traditionally used to nourish the liver and kidney, cool the blood, and arrest bleeding. Ecliptae Herba is used as a Chinese medicinal preparation in decoctions and compound formulations, most notably Er Zhi Wan (二至丸) , a classical two-herb preparation containing Mo Han Lian and Nu Zhen Zi ( Ligustrum lucidum). Materials and Methods Female Wistar rats were allocated to six experimental groups (n = 6/group). PCOS was induced in the designated groups by oral administration of letrozole (1 mg/kg/day) for 21 consecutive days. Following assessment of the induction phenotype, animals received vehicle, metformin (100 mg/kg/day), or E. alba extract (100, 200, or 400 mg/kg/day) orally for a further 21 days. Thus, the study used a post- induction therapeutic/intervention design rather than concurrent treatment during PCOS induction. Estrous cyclicity was monitored by daily vaginal cytology. At the end of treatment, serum hormonal and biochemical parameters, ovarian oxidative- stress- related indices, ovarian weight, and histopathological changes were evaluated. Total phenolic and flavonoid contents were determined using Folin–Ciocalteu and aluminium chloride colorimetric methods, respectively. Results The hydroalcoholic extract yielded 13. 75% w/w and contained 126.84. 84 ± 4. 31 mg gallic acid equivalents and 92. 92.67 ± 3. 14 mg quercetin equivalents per gram of extract. Letrozole- induced PCOS was associated with disrupted estrous cyclicity, with diestrus prolonged to 4. 5 ± 0. 3 days. Treatment with E. alba progressively improved cycle abnormalities, with the 400 mg/kg dose reducing diestrus to 1. 4 ± 0. 2 days. The extract also improved ovarian biochemical and histopathological alterations associated with the PCOS phenotype, with greater effects generally observed at the higher doses. Discussion The results show that hydroalcoholic extract of Eclipta alba ameliorated letrozole- induced reproductive, endocrine, metabolic, and oxidative stress- associated abnormalities in PCOS rats. Such protective effects may stem from its antioxidant and anti- inflammatory activity, resulting in hormonal balance, improved insulin sensitivity, normalization of lipid metabolism, and preservation of ovarian histoarchitecture. Overall, the results suggest that Eclipta alba has multitarget therapeutic potential in the treatment of PCOS and may be a phytotherapeutic agent for oxidative stress- induced ovarian dysfunction. Conclusion Under the conditions of this experimental model, E. alba hydroalcoholic extract produced dose- related improvements in reproductive, hormonal, biochemical, and ovarian alterations associated with letrozole- induced PCOS. These findings support further investigation of E. alba as a promising candidate for PCOS- related pharmacological research.