Antioxidative effect of CLA diet and endurance training in liver and skeletal muscles of rat

The purpose of this study is to investigate the effects of conjugated linoleic acid (CLA) supplementation and endurance exercise on the oxidative/anti-oxidative status in rat liver and skeletal muscles. Sprague-Dawley male rats were randomly divided into HS (high-fat diet sedentary group, n = 8), CS group (CLA supplemented sedentary group, n = 8), and CE group (CLA supplemented exercise group, n = 8). For CLA supplementation, 1.0% CLA was substituted for dietary fat. For endurance exercise, the rats swam for 60 min a day, 5 days a week for 8 weeks. The MDA content, Cu, Zn-SOD and Mn-SOD expression in the soleus muscle (SOM) of the CE group improved significantly compared to the HS (p < 0.01) and CS groups (p < 0.05). Moreover, Mn-SOD expression in both the SOM and extensor digitorum longus muscle (EDL) of the CS were enhanced significantly compared to the HS (p < 0.05). From these results, it was suggested that CLA supplementation under the endurance exercise condition may improve the oxidative status by decreasing the MDA content via potential scavenging of Cu,Zn-SOD, and Mn-SOD protein in red muscle, respectively. Therefore, our study demonstrated long-term endurance exercise with CLA supplementation plays a crucial role for maintenance of antioxidative properties in the skeletal muscle of rat.