Oxidative stress is thought to be a significant contributing factor of age-related sarcopenia. We tested the hypothesis that long-term dietary antioxidant (astaxanthin) intake attenuates sarcopenia. Wistar strain male rats, aged 45 weeks old, were given either control (Cont) or astaxanthin feed (0.004%, Ax) for 1 year. The soleus muscle weight and muscle weight-to-body weight ratios in Ax group were significantly higher than ill Cont group. but tibialis anterior muscle mass was similar between the two dietary groups. The level of ubiquinated proteins was significantly lower in the soleus muscles of Ax group, but not in tibialis anterior muscles when compared with Cont group. Tibialis anterior levels of cathepsin L. espccially, and caspase-3 tended to he lower in Ax group than in Cont group. Cathepsin L levels were significantly lower. Whereas no differences between Cont and Ax were observed in soleus levels. There were no significant differences in Ax supplementation on calpain 1 and 2. UBC3B, Cu/Zn SOD and nitrotyrosine levels in either soleus or tibialis anterior muscles. Our data suggest that long-term dietary astaxanthin intake attenuates age-related muscle atrophy. clue in part, to reduction in ubiquitanation Of myofibrillar protein ill slow soleus muscles, but not in fast tibialis anterior muscles.