Abstract
Obesity is typically linked to oxidative stress and inflammation, which lead to vascular damage and initiate the progression of atherosclerosis. The aim of this study was to determine the anti-atherosclerotic effect of orlistat on obesity-induced vascular oxidative stress in obese male rats. Twenty-four male Sprague-Dawley rats were categorized into two groups: normal (Normal group, n = 6) and high-fat diet (HFD group, n = 12). After six weeks, obese rats in the HFD group were administered either with distilled water (OB group) or orlistat 10 mg/kg/day (OB/OR group) for another six weeks. The OB group had a significant increase in lipid profiles (total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL)) and decrease in high-density lipoprotein (HDL) level compared to the Normal group. The aortic antioxidants enzymes activities (superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), and catalase (CAT)) as well as total glutathione (GSH) and total antioxidant capacity (TAC) of the OB group were significantly decreased compared to the Normal group. Furthermore, pro-inflammatory atherosclerotic markers (tumour necrosis factor-alpha (TNF-ɑ), vascular cell adhesion molecule-1 (VCAM-1), and intercellular cell adhesion molecule-1 (ICAM-1)) expressions were increased significantly, and anti-inflammatory marker (interleukin-10 (IL-10)) was decreased significantly in the OB group compared to the Normal group. Treatment with orlistat significantly improved lipid profile, increased antioxidant enzymes and expression of anti-inflammatory markers, and decreased the expression of the pro-inflammatory marker compared to the OB group. These findings may suggest the therapeutic effect of orlistat in attenuating the progression of the atherosclerotic stage in obesity.