Protective Effects of α-Lipoic Acid on Vascular Oxidative Stress in Rats with Hyperuricemia

The aim of the present study was to observe the protective effects of α-lipoic acid (ALA) on vascular injury in rats with hyperuricemia (HUA). The ALA treatment groups (10, 30 and 90 mg/kg, respectively) were administered with ALA via gavage for 2 weeks. Subsequently, the levels of blood urea nitrogen (BUN), creatinine (CREA), uric acid (UA), total cholesterol (TC), high density lipoprotein-C (HDL-C) and low density lipoprotein-C (LDL-C) were measured; the activities of glutathione peroxidase (GSH-Px), catalase (CAT), malonaldehyde (MDA), superoxide dismutase (SOD) and xanthine oxidase (XOD) were also determined. The thoracic aorta of rats in each experimental group was observed under a light microscope; ultrastructural analysis was performed. SOD and CAT protein contents were investigated by Western blotting. The results revealed that: i) Compared with the model group, the levels of UA were decreased in the ALA groups and the levels of BUN, CREA, TC, and LDL-C decreased in the 30 and 90 mg/kg ALA groups (P<0.05); ii) compared with the model group, the activities of GSH-Px, SOD and XOD were increased and the levels of MDA were reduced in the 90 mg/kg ALA group (P<0.05); and iii) in the model and 10 mg/kg ALA groups, edema and shedding were observed in endothelial cells. Compared with the model and 10 mg/kg ALA groups, the 30 and 90 mg/kg ALA groups exhibited fewer swollen endothelial cells. In summary, the results of the present study indicated that HUA resulted in vascular oxidative stress injury and decreased the activity of antioxidative enzymes, which leads to endothelial cell damage and vascular lesions. ALA may serve as a therapeutic agent for the treatment of HUA-induced endothelial dysfunction.