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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.

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Lycium barbarum polysaccharide (LBP) has been shown to ameliorate insulin resistance, but the identification of compounds from LBP and the mechanisms have not been clarified. In this study, LBP-4a was purified from Lycium barbarum by DEAE cellulose and Sephadex G-100 column chromatography, and the effects of LBP-4a on insulin resistance were investigated. The results indicated that LBP-4a caused translocation of the glucose transporter isoform 4 (GLUT4) to the cell surface, which in turn stimulated glucose uptake, and the effect was sensitive to wortmannin, an inhibitor of phosphoinositol 3-kinase (PI3-K), and SB203580, an inhibitor of p38 mitogen activated protein kinase (p38 MAPK (α, β)). Furthermore, the effects of LBP-4a on p38 MAPK activities were abrogated by pretreatment of rat adipocytes using SB203580. In summary, LBP-4a improved insulin resistance via translocation and activation of GLUT4 in OLETF rats, and the activation of PI3-K and p38 MAPK contributed to these effects.

Portulaca oleracea L. is an annual plant widely distributed from the temperate to the tropical zones. POL-P3b, a polysaccharide fraction purified from Portulaca oleracea L., is able to enhance immunity and inhibit tumor formation. Induction of antitumor immunity by dendritic-tumor fusion cells can be modulated by their activation status. Mature dendritic cells are significantly better than immature dendritic cells at cytotoxic T-lymphocyte induction. In this study, we analyzed the effects of POL-P3b on the maturation and function of murine bone-marrow-derived dendritic cells (DCs) and relevant mechanisms. The phenotypic maturation of DCs was confirmed by flow cytometry. We found that POL-P3b upregulated the expression of CD80, CD86, CD83, and major histocompatibility complex class II molecules on DCs, stimulated production of more interleukin (IL)-12, tumor necrosis factor-α, and less IL-10. Also, DCs pulsed POL-P3b and freeze-thaw antigen increased DCs-driven T cells' proliferation and promoted U14 cells' apoptosis. Furthermore, the expression of TLR-4 was significantly increased on DCs treated by POL-P3b. These results suggested that POL-P3b may induce DCs maturation through TLR-4. Taken together, our results may have important implications for the molecular mechanisms of immunopotentiation of POL-P3b, and provide direct evidence to suggest that POL-P3b should be considered as a potent adjuvant nutrient supplement for DC-based vaccines.