Improving the activity of Lycium barbarum polysaccharide on sub-health mice.

Sub-health has been described as a chronic condition of unexplained deteriorated physiological function, which falls between health and illness and includes fatigue as one of its principal manifestations. Mitochondrial dysfunctions have been discovered in fatigue-type sub-health such as impaired oxidative phosphorylation and mitochondrial damage. In the present study, we evaluated the effects of Lycium barbarum polysaccharide (LBP-4a), a polysaccharide fraction purified from Lycium barbarum, on anti-fatigue in sub-health mice, and the relevant mechanisms were studied. Forty mice were divided into control, model, LBP-4a(L) and LBP-4a(H) groups. Model mice were prepared through compound factors, including forced swim tests, sleep deprivation and wrapping restraint stress tests. After LBP-4a treatment for 4 weeks, the gastrocnemius muscles were obtained for morphological observation and the activities of SOD, GSH-Px and MDA content were detected. Furthermore, mitochondrial membrane potential and Ca(2+) content were measured in isolated skeletal muscle mitochondria. The results showed that LBP-4a could reduce skeletal muscle damage and MDA levels and enhance of SOD and GSH-Px activities compared with the model group. The levels of mitochondrial membrane potential and Ca(2+) were increased in LBP-4a-treated skeletal muscle mitochondria; moreover, the high-dosage group was better than that of the low dosage. In conclusion, LBP-4a exhibited anti-fatigue activity on sub-health mice, and the mechanism was closely correlated with a reduction in lipid peroxidation levels and an increase in antioxidant enzyme activities in skeletal muscle tissue, improving the intracellular calcium homeostasis imbalance and increasing mitochondrial membrane potential. These observations provided the background for the further development of LBP-4a as a type of anti-fatigue therapy used in sub-health treatment.