Hepatic Antioxidant, Oxidative Stress And Histopathological Changes Induced By Nicotine In A Gender Based Study In Adult Rats

Nicotine is generally regarded to be a primary risk factor in the development of hepatic, cardiovascular and pulmonary disorders. Therefore, the current study was designed to compare the extent of the oxidative stress induced by nicotine upon the liver of adult male and female rats. Nicotine toxicity was induced by intraperitoneal injection of 0.5 mg base/Kg body weight for 2 months. Cellular damage of liver was assessed by measuring the activity of serum transaminases. Antioxidant status was assessed in liver by measuring the levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione-S-transferase (GST) and reduced glutathione (GSH). Histopathological liver changes were examined. The results showed a significant elevation in serum ALT and AST in nicotine-treated rats versus control groups. In comparison with the control findings of male and female rats, nicotine-treated male and female rats showed significant increase in MDA content by 57.3 and 41.8% respectively and a significant reduction in GSH levels by 60.1 and 30.7% respectively with observed significant inhibition in GPX activity by 56.5 and 28.6% respectively and a concomitant significant inhibition in GST activity by 71.2 and 51.2% respectively. Also, significant inhibition in SOD activity was achieved in nicotine-treated male and female rats by 66 and 51.6% versus control groups respectively. Male rats appeared to be more susceptible to nicotine toxicity than females. Histological examination of liver tissues in nicotine-treated male and female rats significantly revealed marked tissue damage and changes versus control counterparts. These changes included focal and confluent necrosis, portal tract inflammation and steatosis. These changes being more obvious and severe in male rats. In conclusion, the results showed the existence of significant sex dependent difference between male and female rats towards nicotine toxicity. Further studies are required to elucidate the precise gonadal hormones mechanism upon the sex dependent difference. Keywords: Liver, Nicotine, Sex, Oxidative Stress, Antioxidants. Egyptian Journal of Biochemistry and Molecular Biology Vol. 26 (2) 2008: pp. 189-20