Low-dose Nicotine Exposure Induced the Oxidative Damage of Reproductive Organs and Altered the Sperm Characteristics of Adolescent Male Rats

Background: Nicotine is a major toxic and hazardous component of cigarette smoke, and it has been widely used in nicotine replacement therapy (NRT). This study was aimed to investigate the effects of chronic low-dose nicotine on sperm characteristics and reproductive organ integrity in adolescent male Sprague-Dawley rats. Methods: Twelve rats were equally divided into two groups. Group I received normal saline, and group II received 0.6 mg/kg body weight nicotine intraperitoneally for 28 consecutive days. At the end of the experimental period, sperm was collected for sperm characteristic evaluation, and the testes and prostate were isolated for biochemical and morphological analysis. The effects of nicotine on the body and reproductive organ weights of the animals were evaluated. Results: Chronic nicotine treatment significantly (P < 0.05) altered the sperm count, motility, viability, and morphology, and remarkably increased the malondialdehyde (P < 0.001) and advanced oxidation protein product (P < 0.05) levels in the testes and prostate of nicotine-treated group compared to control group. Moreover, nicotine caused a significant decrease (P < 0.05) in the superoxide dismutase activity of the testes. No significant differences were observed in the reduced glutathione level in both of the testes and prostate of nicotine group compared with control group. Nicotine also induced histopathological alteration in the testes. Conclusion: A low-dose nicotine exposure at 0.6 mg/kg caused detrimental effects on sperm characteristics and induced oxidative stress in the testes and prostate.