The present research aimed to evaluate the ameliorating effect of Rutin as natural antioxidant on oxidative
stress induced in experimental rats exposed to chronic toxicity with Pirimiphos methyl (POM), as one of
organophosphorous pesticides widely used in the Middle East, through evaluation of erythrocytes and brain
biomarkers. The rats were divided into four equal groups. 1) Control Normal group (C): received no drugs.
2) POM group (P): received single oral dose of POM (50 mg/ Kg b.w) daily for 3 months. 3) Rutin group
(R): received single dose of Rutin (45 mg/ Kg b.w) per os daily for 3 months. 4) Rutin + POM group (R +
P): received single dose of POM (50 mg/ Kg b.w) + rutin (45 mg/ Kg b.w) orally daily for 3 months. Blood
and brain samples were collected from all animal groups three times at one, two and three months from the
onset of experiment and used for determination of erythrocytes and brain antioxidant enzyme activities,
reduced glutathione (GSH), lipid peroxides (MDA), in addition to serum nitric oxide (NO) and
ceruloplasmin. (POM) induced a significant decrease in erythrocytes and brain AChE, CAT, GSH,
erythrocytes GPx, GR and GST activities, and a marked increase in erythrocytes SOD, serum GGT activities
and ceruloplasmin concenteration. Also a significant increase in erythrocytes and brain MDA and serum
NO level were observed. Rutin administration to POM intoxicated rats was able to counter act the oxidative
stress induced by POM through the significant increase in the activities of erythrocytes and brain CAT,
GSH, erythrocytes GPx, GR and GST activities. In addition, a marked decrease in erythrocytes and brain
MDA and serum NO level were observed. The results of the present study suggest that rutin has the potential
to exert a protective effect against oxidative stress induced by organophosphorous pesticides