Renal and hepatic toxicity of methomyl and ameliorative effects of green tea (Camellia sinensis) administration

This study was conducted to test the toxicity of the carbamate insecticide (methomyl) and to evaluate the ameliorative effect of green tea (Camellia sinensis) administration. Male albino rats (Rattus norvegicus) were used as test animal model organism. A total of 30 rats were divided into 6 groups and assigned as: G1 (control), G2 (green tea in drinking water at a rate of 6 g/300 ml), G3 (methomyl at a dose of its corresponding ADI; 0.025 mg/kg b.w.), G4 (methomyl at a dose of 10X- ADI; 0.25 mg/kg b.w.), G5 (methomyl ADI + green tea), and G6 (methomyl 10X- ADI + green tea). Methomyl was given daily by gavages. Compared to control results, the body weights in G2 had recorded slight decrease, while that of G5 & G6 recorded high significant decrease. The two later groups showed significant increase of liver and spleen weights, and decrease of kidney, heart and testes weights. In control group, ALT and AST were 25.0 and 63.06 U/mL, respectively, while G4 were 74.61 and 75.53 U/mL, respectively. Lipid peroxidation (LPO) as MDA was highly elevated in methomyl treatments (G3 &G4), while SOD was strongly decreased in these treatments. Based on MDA results, the "Ameliorative Index; AI" for green tea in conjunction with methomyl, equaled to 1.2 and 1.1 for the low and high doses, respectively. In the case of SOD, the AI reached 0.74 and 0.7, respectively. These results revealed the ameliorative effect of green tea against methomyl intoxication. Also, the other measured biochemical parameters (e.g., ALT, AST, ALP, TAC, Creatinine, Urea, BuChE) were normalized due to administration of green tea when given with the insecticide. In conclusion, green tea achieved some body weight decrease. However, it alleviated the oxidative stress induced by methomyl.