Effect of Morus alba L. Fruit Extract on Sperm Quality, Testosterone Profile, and Testicular Histology in Male Rats

Morus alba L. fruit extract (MFE), which is rich in cyanidin 3-glucoside (C3G), demonstrates antioxidant properties and pharmacological effects, but its reproductive safety remains poorly understood. Polyphenols modulate steroidogenesis, spermatogenesis, and sperm acrosome integrity; therefore, toxicity assessment is needed for use. This study aimed to evaluate the antioxidant profiles and subchronic reproductive effects of MFE. MFE was standardized using high-performance liquid chromatography (HPLC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. Male rats were administered MFE (250 or 500 mg/kg BW) for 56 days. Assessments included computer-assisted sperm analysis (CASA), testosterone, seminal fructosamine, and testicular CYP11A1 and androgen receptor (AR) expression. Acrosomal status was determined using PNA lectin staining. The results showed that MFE contained C3G (119.42 mg/g), antioxidant capacity (DPPH IC50: 0.101 mg/mL; FRAP: 465.01 µmol Fe (II)/g), and total contents (phenolics: 41.15 mg GAE/g; flavonoids: 3.15 mg CE/g; anthocyanidins: 11.04 mg C3G/g). MFE did not alter testicular histology and seminiferous stages VII-IX. High doses significantly increased sperm concentration, while both doses reduced sperm beat cross frequency. Testosterone, fructosamine, and CYP11A1/AR expressions showed increasing trends. Significantly, high doses induced a precocious acrosome reaction. In conclusion, MFE has no reproductive toxicity and pro-fertility effects on sperm quantity or androgenic markers, supporting safe subchronic use.