Disuse-induced capillary regression in skeletal muscle is related to overexpression of oxidative stress and/or disorder of endocapillary cell following generation of oxidative stress. We hypothesized that astaxanthin, as an antioxidant supplement, is able to attenuate oxidative stress induced by disuse, and the attenuation consequently lead to inhibit capillary regression in atrophied skeletal muscle. The purpose of the present study was to identify antioxidant effect of astaxanthin, and then to investigate preventive effects of astaxanthin on capillary regression of soleus muscle during hindlimb unloading. Twenty-four male Wistar rats were used in the present study. Rats were divided into control, control plus astaxanthin treatment, hindlimb unloaded, or hindlimb unloaded plus astaxanthin treatment group for seven days. Hindlimb unloading without astaxanthin resulted in a loss of muscle weight and a decrease of the number of capillaries. Additionally, hindlimb unloading without astaxanthin caused an overexpression of superoxide dismutase (SOD-1), and a decreased expression level of vascular endothelial growth factor (VEGF), whereas hindlimb unloading with astaxanthin maintained the expressions of SOD-1 and VEGF at the control level, prevented disuse-induced capillary regression. These results suggest that astaxanthin is effective to attenuate oxidative stress and capillary regression in disuse muscle atrophy.
