Investigation of the hypoglycemic and antioxidant effects of lycopene in chlorpyrifos-treated diabetic rats

Recent studies indicate that increased free radicals and lipid peroxidation play a major role in the toxicity of pesticides and pathogenesis of many diseases like diabetes. It has been know that one of adverse effects in human and animals exposure to organophosphorus compounds is hyperglycemia. For this reason, we aimed to investigate the possible antioxidant and hypoglycaemic effect of lycopene on chlorpyrifos induced oxidative stres and hyperglycemia in normal (non-diabetic) rats and STZ-induced diabetic rats.In this study, 56 adult Wistar albino rats were used. Rats were randomly divided into eight groups, n=7: These groups were named as K (0,5 ml corn oil), D,KP (2,7 mg/kg chlorpyrifos ethyl), L (10 mg/kg lycopene), D+KP (2,7 mg/kg chlorpyrifos), D+L (10 mg/kg lycopene), L (10 mg/kg lycopene) + KP (2,7 mg/kg chlorpyrifos ethyl), D+L (10 mg/kg lycopene) + KP (2,7 mg/kg chlorpyrifos ethyl). D group rats received a single dose of STZ (50 mg/kg) intraperitoneally. K, KP and L groups rats were given corn oil, chlorpyrifos and lycopene by oral gavage for 28 consecutive days. Rat weight gains and fasting blood glucose were measured every week for 4 weeks. At the end of the study MDA and GSH were assessed in whole blood. SOD, CAT, GPx, insulin, AkE and NO were determined in plasma. AST, ALT, glucose, TNF-? and TAK were assessed in serum.In this study, the treatment of rats with a single dose of STZ (50 mg/kg body weight) and chlorpyrifos was showed that decreased in plasma insulin level while fasting blood glucose and serum glucose increased compared to the control group. Moreover the treatment of rats with a single dose of STZ (50 mg/kg body weight) and chlorpyrifos was revealed significant increased in MDA while TAK and GSH levels was decreased with a consistently significant decreased in the activity ofantioxidative enzymes (SOD, CAT, GPx). Administration of lycopene to rats in D and KP groups was showed that cause a decreased in glucose level, an increased of insulin concentration but had not effect on D+KP group. Moreover administration of lycopene to rat in D group was found that decrease in MDA while TAK and GSH levels was increased with a consistently increased in the activity of antioxidative enzymes (SOD, CAT, GPx). Also, lycopene dose that used present study had not a positive effect on KP and D+KP induced oxidative stres.101This study suggests that lycopene acts as an safe and efficient choice in helper to treatment of diabetes and chlorpyrifos induced hyperglycemia and their complications. Furthermore it concluded that need for further research on utilization of lycopene at higher doses or in combination with other antioxidants in pesticide toxication with diabetic human and animals.Key Words: Diabetes mellitus, hyperglycemia, chlorpyrifos ethyl, lycopene, oxidative stress