Effect of a High-Cholesterol Diet on Antioxidative/Prooxidative Balance in Rabbits

Hypercholesterolemia can increase oxidative stress through elevation of reactive oxygen species (ROS) production. The aim of the present study was to investigate the antioxidative/prooxidative balance in rabbits receiving high-cholesterol diet for two months. Sixteen rabbits were randomly divided into two groups: the control group which received 100 g normal chow diet daily; and the treatment group with the same diet plus 2% of cholesterol. The blood sample was obtained at first, days 20, 40, and 60 of the experiment. Plasma was separated and kept at -76C until use. The lipid profile was determined using enzymatic method. Superoxide dismutase and glutathione peroxidase activities were measured spectroscopically. Malondialdehyde (MDA) level and paraoxonase 1 (PON1) activity was determined by means of thiobarbituric acid and chemical methods, respectively. At the end of intervention period, there was a significant increase in the plasma cholesterol (P=0.02), triglyceride (P<0.001), and LDL-C (P=0.041) concentrations; while level of HDL-C decreased significantly (P =0.036). The PON1 activity showed a decreased trend during the first two months reaching to 2.5 from 3.23 µmol/min/ml at the end of the experiment (P=0.001). However, there was about two-fold increase in the MDA level (from 6.770.91 to 14.503.00 nmol/ml, P=0.003). The superoxide dismutase and glutathione peroxidase activities were increased significantly (P=0.001 and P<0.001, respectively). An athrogenic diet can affect the lipid and lipoprotein profiles through changing the metabolic process. Meanwhile, this diet is also able to increase oxidative stress by disturbing antioxidative/prooxidative balance which, in turn, may lead to atherosclerosis development and progression.