Objective: 

Methyl parathion and dichlorvos are organophosphate (OP) pesticides. They have been shown to induce oxidative stress in erythrocytes through the generation of free radicals and alteration of the cellular antioxidant defense system.

Methods: 

In this study, we investigated the effect of several different doses of methyl parathion and dichlorvos (1,10,100mM) or methyl parathion or dichlorvos in combination vitamin C (VC; 10mM) or vitamin E (VE; 30mM), on the levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities in human erythrocytes in vitro. Erythrocytes were incubated under various treatment conditions (methyl parathion/ dichlorvos/vitamins alone, methyl parathion plus vitamins, and Dichlorvos plus vitamins) at 37 °C for 60 min.

Results: 

Treatment with methyl paration or dichlorvos alone increased the levels of MDA, and decreased SOD, CAT and GPx activities in erythrocytes (P<0,05). There were no statistical different among VC-treated, VE-treated, or VC+VE-terated erythrocytes, as compared with nontreated control cells. Treatment of cells with methyl parathion or dichlorvos+VC, methyl parathion or dichlorvos+VE, or a combination of all three agents prevented Methyl parathion or dichlorvos-induced changes in antioxidant enzyme activity and lipid peroxidation. However, this effect was seen only at low concentrations of methyl parathion or dichlorvos (1 and 10mM), and combination of VC+VE had a more protective effect than VC or VE alone.

Conclusions: 

These results indicated that the presence of vitamins at concentrations that are similar to the levels found in plasma have no effect on methyl parathion or dichlorvos-induced toxicity in erythrocytes at a cncentration of methyl parathion or dichlorvos (100 mM) that are typically used in pesticides.