Study on the protective effect of hydroalcoholic Olive Leaf extract (oleuropein) on the testis and sperm parameters in adult male NMRI mice exposed to Mancozeb

This study aimed to assess the protective effects of the Olive Leaf Extract (OLE) against Mancozeb (MZB)-induced reproductive damage in male NMRI mice. In this experimental study, NMRI mice were randomly divided into 7 groups (n = 8) including 1: control, 2: MZB, 3: MZB + OLE (200 mg/kg), 4: MZB + OLE (400 mg/kg), 5: MZB + atropine (0.25 mg/kg), 6: OLE (200 mg/kg) and 7: OLE (400 mg/kg). Mice were sacrificed after 5 weeks, and blood samples were drawn to measure serum testosterone level. Sperm samples were collected and analyzed according to standard criteria. The left testis was removed to assess testicular parameters using H&E staining. The Protamine level and DNA fragmentation were determined by chromomycin A3 (CMA3) and SCD assays, respectively. Sperm viability decreased in MZBinduced groups. Also, the sperm's protamine deficiency (higher than 30%) and DNA fragmentation increased within MZB induced. There were significantly higher structural deformities of sperm's head, neck, and tail in MZB-treated groups as well (p < 0.05). Within treated groups with OLE, these sperm factors could repair defects versus MZB group. Furthermore, there were significant differences comparing sperm motility (type A, B, and D); protamine level, DNA fragmentation (SCD1, SCD3, and SCD4), and testosterone levels compared to the groups (p < 0.05). Sperm motility, seminiferous tubules diameter, the height of the germinal epithelium, and testosterone level within OLE 200 mg/kg was higher than other groups, while these factors in OLE 400 mg/kg was less than OLE 200 mg/kg. Results showed that oral administration of OLE could be useful in ameliorating MZB induced toxicity in the reproductive system of male mice within 200 mg/kg dosage; while OLE 400 mg/kg probably could exacerbate the harmful effects.