Cadmium (Cd) is a well-known human carcinogen and a potent nephrotoxin.The present study was carried to evaluate the protective effectsof alpha-lipoic acid and melatonin against cadmium (cd) induced oxidative stress to erythrocytes in rats. One hundred male albino rats were divided into five groups containing 20 rats each.Group I: (control) administered distilled water. Group II:(Cadmium exposed group) received cadmium chloride (4.4 mg/kg body weight of 1/20th of LD50) orally and once per day over a period of 10 weeks. Group III:(Cadmium +Alpha-lipoic acid treated group) received cadmium chloride (4.4 mg/kg body weight) and treated daily with alpha-lipoic acid (54 mg/kg body weight/ i.p). Group IV:(Cadmium +Melatonin treated group) received cadmium chloride (4.4 mg/kg body weight) and treated daily with melatonin(10 mg/kg body weight/orally). Group V :(Cadmium +alpha-lipoic acid and melatonin treated group). Heparinized blood used for Glucose -6-phosphate dehydrogenase and hemoglobindetermination. Plasma used for determination of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and Gamma-glutamyltransferase (γ - GT) activities, and urea, creatinine, total cholesterol and phospholipids concentrations. Moreover, erythrocyte hemolysate were processed for the determination of L-Malondialdhyde (L-MDA), catalase (CAT), superoxide dismutase (SOD), Glutathione- s-transferaseand (GST) and reduced Glutathione (GSH). Also, liver and kidney specimens were excised for histopathological examinationand for cadmium residues determination. The obtained results revealed that, a significant increase in plasma ALT , AST and GGT activities , urea, creatinine, total cholesterol and phospholipids concentrations and erythrocyte L-MDA level, SOD activity ,Liver and kidney cadmium residue were observed in cadmium intoxicated rats. However, administration of alpha-lipoic acid, melatonin and their combination in cadmium intoxicated rats exhibited a significant decreased in all mentioned parameters. On the other hand, a significant decreased in erythrocyte CAT, GST and G-6-PDH activities, GSH and hemoglobin concentrations were observed in cadmium intoxicated rats. Meanwhile, alpha-lipoic acid and melatonin administrations alone and in combination in cadmium intoxicated rats resulted in significant increase in all mentioned parameters. The histopathological studies in the liver and kidney of rats also supported that alpha-lipoic acid and melatonin markedly reduced the Cd induced pathological changes and preserved the normal histological architecture of the liver and kidney tissues.It could be concluded that, the potential of alpha-lipoic acid and melatonin as a powerful agents and may be useful as an antioxidants in combating free radical-induced oxidative stress and tissue injury that is a result of cadmium toxicity. Also, these compounds have a protective antioxidant effect and could be also applicable as a cytoprotective against oxidative stress of tissue damage mediated by heavy metals intoxication. |
