Oxidative stress and cholinesterase inhibition in saliva and plasma of rats following subchronic exposure to malathion.
The aim of this study was to examine whether malathion, a commonly used organophosphate (OP), might induce oxidative stress and cholinesterase (ChE) depression in saliva and plasma in rats following subchronic exposure mimicking human exposure. Malathion was administered orally at doses of 100, 500 and 1500 ppm for 4 weeks. Oxidative stress was determined by measuring the malondialdehyde concentration, the end product of lipid peroxidation, and assessing total antioxidant power. Four weeks oral administration of malathion at doses of 100 ppm, 500 ppm and 1500 ppm depressed plasma ChE activity to 45% (P<0.01), 48% (P<0.01) and 41% (P<0.01) of control, respectively. Malathion at doses of 100 ppm, 500 ppm and 1500 ppm depressed saliva ChE activity to 73% (P<0.01), 75% (P<0.01) and 78% (P<0.01) of control, respectively. Malathion at doses of 100 ppm, 500 ppm and 1500 ppm increased plasma antioxidant power by 33% (P<0.01), 59% (P<0.01) and 118% (P<0.01) of control, respectively. Malathion did not change saliva antioxidant power. Malathion at doses of 100 ppm, 500 ppm and 1500 ppm increased plasma thiobarbituric acid reactive substances (TBARS) by 61% (P<0.01), 69% (P<0.01) and 63% (P<0.01) of control, respectively. Malathion at doses of 500 ppm and 1500 ppm increased saliva TBARS by 19% (P<0.01) and 22% (P<0.01) of control, respectively. Malathion (100 ppm) did not change saliva TBARS level. We concluded that in OP subchronic exposure, depression of ChE is accompanied by induction of oxidative stress that might be beneficial in monitoring OP toxicity.
Abdollahi
Mohammad
M
Department of Toxicology and Pharmacology, Faculty of Pharmacy and Laboratory of Toxicology, Pharmaceutical Sciences Research Centre, Tehran University of Medical Sciences, Tehran 14155-6451, Iran. mohammad.abdollahi@utoronto.ca
Mostafalou
Sara
S
Pournourmohammadi
Shirin
S
Shadnia
Shahin
S
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002800:Cholinesterase Inhibitors / Q000633:toxicity*; D002802:Cholinesterases / Q000097:blood / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D008294:Malathion / Q000633:toxicity*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012463:Saliva / Q000187:drug effects / Q000201:enzymology*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000975:Antioxidants; D002800:Cholinesterase Inhibitors; D017392:Thiobarbituric Acid Reactive Substances; D002802:Cholinesterases; D008294:Malathion