Synergistic Modulation of Hormonal Balance and Ovarian Architecture by Clomiphene–Letrozole Co-Administration in a Rodent Model of Hyperandrogenism

Abstract

Infertility, defined as the inability to achieve pregnancy after 12 months of regular unprotected intercourse, remains a major reproductive health challenge. Hyperandrogenism is a key contributor to polycystic ovarian syndrome (PCOS), one of the leading causes of female infertility. Although clomiphene citrate and letrozole are widely used as ovulation-inducing agents, their combined therapeutic potential remains poorly understood. This study investigated the effects of clomiphene–letrozole co-administration on hormonal profile, inflammatory cytokines, oxidative stress, and ovarian histomorphology in a rat model of hyperandrogenism. Thirty female Wistar rats were randomly assigned into five groups (n = 6). Group A received saline and served as the control, while groups B–E were administered testosterone enanthate (10 mg/kg, subcutaneously) for 35 days to induce a PCOS-like condition. Group B served as the untreated PCOS control. Thereafter, groups C, D, and E received clomiphene (100 µg/kg), letrozole (5 mg/kg), or a combination of both agents, respectively, for 10 days. Combined clomiphene–letrozole treatment significantly reduced body and ovarian weights, lowered glucose levels, and improved oestradiol and follicle-stimulating hormone profiles compared with untreated PCOS rats. Co-administration also enhanced antioxidant status, reduced lipid peroxidation, and favourably modulated inflammatory cytokines by decreasing IL-1β and TNF-α while increasing IL-10 levels. Histological examination revealed cystic follicles and basement membrane thickening in untreated PCOS rats, while treated groups showed varying degrees of ovarian recovery, with the combination therapy demonstrating the greatest improvement. These findings suggest that clomiphene–letrozole co-administration may provide superior therapeutic benefits over monotherapy in managing PCOS-related infertility.