Mercury chloride-induced oxidative stress in human erythrocytes and the effect of vitamins C and E in vitro

Mercury can exist in the environment as metal, as monovalent and divalent salts and as organomercurials, one of the most important of which is mercuric chloride (HgCl sub(2)). It has been shown to induce oxidative stress in erythrocytes through the generation of free radicals and alteration of the cellular antioxidant defense system. The effect of simultaneous pretreatment with vitamins C and E on the toxicity of HgCl sub(2) in human erythrocytes was evaluated. We examined the effect of several different doses of HgCl sub(2) (1.052, 5.262, 10.524 kM), or HgCl sub(2) in combination with vitamin C (VC; 10 kM) and vitamin E (VE; 30 kM), on the levels of malondialdehyde (MDA) and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities in human erythrocytes in vitro. Erythrocytes were incubated under various treatment conditions (HgCl sub(2) alone, vitamins alone, or HgCl sub(2) plus vitamin) at 37C for 60 min and the levels of MDA and SOD, CAT and GPx activities, were determined. Treatment with HgCl sub(2) alone increased the levels of MDA and decreased SOD, CAT and GPx activities in erythrocytes (P < 0.05). VC and VE-pretreated erythrocytes showed a significant protection aganist the cytotoxic effects induced by HgCl sub(2) on the studied parameters. There were no statistical differences among VC+VE-treated erythrocytes, as compared to non-treated control cells. These results indicated that the presence of vitamins at concentrations that are similar to the levels found in plasma could be able to ameliorate HgCl sub(2)-induced oxidative stress by decreasing lipid peroxidation and altering antioxidant defense system in erythrocytes.