en تخصصي Special پژوهشي Research <p><strong>Background:</strong> Arsenic as an environmental toxicant is able to induced oxidative stress. The present study aimed to evaluate of vitamin C supplementation on the paraoxonase1 (PON1) arylesterase activity (responsible for <a href="https://en.wikipedia.org/wiki/Hydrolysis" title="Hydrolysis">hydrolysing</a> lipid-peroxides) in rat exposed to arsenic.</p> <p><strong>Methods:</strong> The study was conducted in the Faculty of Veterinary Medicine, Tabriz Islamic Azad University, Tabriz, Iran in 20015. Thirty-two adult male rats weighing 200-350 g were randomly divided into 4 groups: group I (Normal healthy rat), group II [treated with sodium arsenite (100 ppm in drinking water)], group III [treated with vitamin C supplementation (200 mg/kg via gavage)] group IV (treated with sodium arsenite and vitamin c 100 ppm and 200 mg/kg respectively).</p> <p><strong>Results:</strong> Vitamin C supplementation increased paraoxonase1 (PON1) arylesterase activity (<em>P</em><0.05) but had no significant effect on serum levels of HDL, triglyceride and cholesterol<strong>.</strong></p> <p><strong>Conclusion:</strong> PON1 arylesterase activity is independent of changes in HDL and lipid profile, and vitamin C with different mechanisms such as radical scavenging activity and reduction of oxidative stress leads to increased activity of paraoxonase.</p> Arsenic, Paraoxonase 1, Rat, Vitamin C 47 50 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-405-1&slc_lang=en&sid=1 Felor Zargari zargarifkb@gmail.com 10031947532846006083 10031947532846006083 Yes Department of Medical Science, Marand Branch, Islamic Azad University, Marand, Iran. Hamid Tabaghchi Saeedy 10031947532846006084 10031947532846006084 No Department of Biology, Ahar Branch, Islamic Azad University, Ahar, Iran.