Evaluation of the Protective Effect of Hydroethanolic Extract of Peppermint (Mentha piperita L.) on Fertility Indicators in Male Wistar Rats Treated with Methyl Tert-Butyl Ether

Methyl tert-butyl ether (MTBE) is a persistent environmental contaminant associated with reproductive toxicity, primarily through oxidative stress. Peppermint (Mentha piperita L.) is a medicinal plant with strong antioxidant activity that may protect against chemically induced reproductive damage. This study investigated the protective effects of the hydroethanolic extract of peppermint on MTBE-induced reproductive toxicity in adult male Wistar rats. Twenty-eight rats were randomly divided into four groups (n = 7): control, MTBE, MTBE plus peppermint extract (125 mg/kg), and MTBE plus peppermint extract (250 mg/kg). Rats were exposed to MTBE for 24 days, followed by oral administration of peppermint extract for 24 days. Serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone, sperm characteristics, testicular malondialdehyde (MDA) levels, and histopathological changes were assessed. MTBE exposure significantly reduced serum FSH, LH, testosterone, sperm count, and sperm viability, while increasing abnormal sperm and MDA levels. Histological examination revealed vacuolization of Sertoli cells and decreased Leydig cell density. Treatment with peppermint extract significantly improved hormonal profiles, sperm quality, and testicular histology, while reducing MDA levels, with the 250 mg/kg dose producing greater effects than the lower dose. These findings suggest that the hydroethanolic extract of M. piperita alleviates MTBE-induced reproductive toxicity, likely through its antioxidant activity, and may represent a promising natural therapeutic agent for protecting male reproductive function against oxidative stress-induced damage.