Protective Effects of Eugenol Against Monosodium Glutamate-Induced Reproductive Toxicity in Male Wistar Rats.

Monosodium glutamate (MSG), a widely used flavor enhancer, has been implicated in oxidative stress-mediated systemic and reproductive toxicity, particularly affecting the male gonadal system. This study evaluated the ameliorative potential of eugenol, a phenolic compound with potent antioxidant properties, against MSG-induced reproductive toxicity in male Wistar rats. Thirty rats were randomly divided into five groups: group 1 (control), group 2 (MSG 2.5 g/kg), group 3 (eugenol 200 mg/kg), group 4 (MSG + eugenol 100 mg/kg), and group 5 (MSG + eugenol 200 mg/kg). Treatments were administered orally for 28 days. Hematological, biochemical, hormonal, antioxidant, gross, and histopathological assessments were conducted after sacrifice on Day 29. MSG exposure significantly reduced testicular weight, testosterone levels, TEC, Hb, PCV, serum proteins, and testicular GSH and SOD, while markedly elevating TLC, AST, ALT, BUN, creatinine, and TBARS. Severe testicular degeneration, vascular congestion, germ-cell loss, and disrupted seminiferous tubules were observed histologically. Co-administration of eugenol resulted in significant and dose-dependent amelioration of MSG-induced alterations, restoring hematological and biochemical parameters, improving antioxidant status, and elevating testosterone levels. Gross pathology and histopathology demonstrated progressive structural recovery, with the higher eugenol dose showing near-normal testicular architecture and active spermatogenesis. Eugenol alone produced no adverse effects and remained comparable to the control group across all parameters. The findings indicate that eugenol confers strong protective effects against MSG-induced reproductive toxicity, primarily through its antioxidant and cytoprotective actions. Eugenol may serve as a promising natural therapeutic agent for mitigating chemically induced male reproductive impairments.