Biochemical effects of some pesticides on lipid peroxidation and free-radical scavengers.

Oxidative stress was studied in blood samples obtained from lindane, malathion and propoxur poisoning cases admitted to the Guru Teg Bahadur Hospital, Delhi and evaluated for lipid peroxidation, oxygen free radical (OFR) scavenging enzymes, and glutathione (GSH) and related enzymes. Acetylcholine esterase (AChE), gamma glutamyl transpeptidase (GGT) and GSH level were also assayed in lymphocytes. The level of thiobarbituric acid reacting substances and activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and GGT were increased and GSH level was decreased in pesticide poisoning. Apparently lindane (at the concentration examined) was more potent than malathion and propoxur in producing alteration in lipid peroxidation, GSH related parameters and OFR scavenging enzymes. However, AChE activity and GSH level in lymphocytes of malathion poisoning cases were reduced and GGT activity was enhanced in comparison to control subjects. The present results suggest that OFR scavenging enzymes were induced while combating oxidative stress in a differential manner in organochlorine, organophosphate and carbamate poisoning. Increased lipid peroxidation, coupled with altered levels of GSH and OFR scavenging enzymes in the blood are discussed in the light of oxidative stress.