Free radical and antioxidant status among organophosphate pesticide exposed sprayers

To study the antioxidant status and the extent of oxidative stress in organophosphate pesticide exposed sprayers.

The study was conducted in 50 organophosphate pesticide (OP) poisoned sprayers. Superoxide dimutase (SOD), catalase (CAT) and malondialdehyde(MDA) were estimated as an index of antioxidant status and oxidative stress respectively and comparisons were made in the levels of cholinesterases (AChE;BuChE) and glutathione(GSH) between healthy control subjects and OP poisoned sprayers.

There were significantly fall in both blood AChE and BuChE in the pesticide exposed group as a result of multiple exposures to mixture of OP pesticides. Blood AChE and BuChE showed decrease of 18.4% and 18% respectively in the exposed group. Blood GSH levels, an antioxidant molecule was also found to be significantly lowered in the OP pesticide exposed group. The increase in lipid peroxidation as reflected by elevated levels of MDA in the pesticide exposed group indicates oxidative stress. Exposure to OP pesticide showed elevated RBC-SOD activity in this study, SOD effectively dismutases superoxide anion into hydrogen peroxide and O₂. The RBC-CAT activity was also found to be elevated in the exposed workers in this study as a result of OP pesticide induced poisoning. The increased activity of CAT seen in the poisoning cases coupled with an increase in the blood lipid peroxidation level (MDA) suggests an insufficient antioxidant defense.