Oxidative stress in acute human poisoning with organophosphorus insecticides; a case control study.

Free radicals play an important role in toxicity of pesticides and environmental chemicals. Organophosphorus insecticides (OPIs) may induce oxidative stress leading to generation of free radicals and alteration in antioxidant system. To complete the previous surveys, this study was conducted to evaluate the existence of oxidative stress, balance between total antioxidant capacity and oxygen free radicals in patients with acute OPI exposure. In this case control study, a total of 22 acute OPI poisoning patients were included and blood samples were analyzed for lipid peroxidation, total antioxidant capacity, total thiol groups, and cholinesterase levels. The results showed significant lipid peroxidation accompanied with decreased levels of total antioxidant capacity, total thiols, and cholinesterase activity. A significant correlation existed between cholinesterase depression and reduced total antioxidant capacity. It is concluded that oxygen free radicals and their related interactions like lipid peroxidation are present in acute OPI poisoning. Use of antioxidants may be beneficial in treatment of OPIs acute poisoning which remains to be elucidated by further clinical trials.