Impact of polycyclic aromatic hydrocarbons and hydrogen peroxide mixture on semen quality parameters and histology of the testes of male Wistar rats

This study evaluated the impact of benzo(a)pyrene (BZ) and naphthalene (NT), members of polycyclic aromatic hydrocarbons (PAHs) and hydrogen peroxide (H₂O₂) on semen quality parameters in Wistar rats and assessed the ameliorative potential of Vitamin C. Fifty-six rats were randomly assigned to seven groups (n = 8 per group): control (Group 1), PAHs only (Group 2), H₂O₂ only (Group 3), PAHs + low-dose H₂O₂ (Group 4), PAHs + high-dose H₂O₂ (Group 5), H₂O₂ + Vitamin C (Group 6), and PAHs + H₂O₂ + Vitamin C (Group 7). Semen samples from the cauda epididymis were subjected to analysis. Treatments lasted two weeks. Semen analysis revealed significant reproductive impairment. The control group exhibited high sperm viability (97.50 ± 10.61%), normal sperm morphology (82.50 ± 3.54%), and robust sperm counts (650.0 ± 212.1 ×10⁶/mL). Groups 2 and 3 showed decreased viability (65.00 ± 7.07% and 90.00 ± 7.07%, respectively) and reduced sperm counts (550.0 ± 70.7 and 504.0 ± 282.8 ×10⁶/mL). Group 5 (high-dose H₂O₂) showed further reductions in viability (87.50 ± 10.61%) and sperm count (350.0 ± 212.1), while Vitamin C cotreatment (Group 7) improved these parameters (viability: 92.50 ± 3.54%; sperm count: 450.0 ± 212.1). Histopathological analysis (H&E, X400) revealed normal testicular architecture in the control group, while Groups 2 and 5 exhibited severe degeneration, including necrosis, vacuolation, germinal epithelium thinning, and significant cell loss. Groups 3, 4, 6, and 7 displayed moderate to severe tissue distortions. These findings underscore the detrimental effects of BZNT and oxidative stress on semen quality and highlight the protective role of Vitamin C in mitigating reproductive toxicity.