Efficacy of Melatonin against Oxidative Stress, DNA Damage and Histopathological Changes Induced by Nicotine in Liver and Kidneys of Male Rats

Abstract

The present study was carried out to investigate and compare the effect of nicotine alone and in combination with melatonin on some oxidants and antioxidant parameters, histopathological changes and DNA integrity in the liver and kidneys of male rats. For this purpose 75 mature male rats weighing 120-140g were randomly divided into five groups; control group (1% ethanol in saline), nicotine group (rats administrated nicotine at a dose of 0.6mg/kg body weight; BW) and nicotine and melatonin groups (rats administrated the same dose of nicotine plus 1, 5 or 10mg/kg BW melatonin, respectively). Nicotine and ‏ melatonin were injected intraperitoneally daily for 21days. Fasting blood samples were collected from each rat one day after the end of last injection (at 22nd day) and sera were collected for determination of total antioxidant capacity (TAC). Five rats were sacrificed from each group; Liver and kidneys were collected for estimation of oxidative stress parameters (MDA, SOD and GSH), histopathological examination and for estimation of DNA damage. The results revealed that nicotine increased MDA, decreased TAC, SOD and GSH, induced histopathological changes and increased the percentage of DNA damage in the liver and kidneys Melatonin administration with nicotine counteracted the effect of nicotine on previous parameters. The effect of melatonin was dose dependent and the 10mg dose produced the highest protective effect. It is concluded that melatonin can ameliorate the harmful effect of nicotine on the liver and kidneys of male rats.