Protective Effect of Ganoderma lucidum Polysaccharide on Myocardial Tissue in Mice under Exercise Fatigue

Objective: To study the protective effect of Ganoderma lucidum polysaccharide (GLP) on myocardial tissue of exercise-induced fatigue mice. Method: GLP was extracted by boiling water. The exhaustive swimming model and incremental load swimming fatigue model of mice were established respectively. The exhaustive swimming time, anti-fatigue and antioxidant related indexes of mice were measured. Moreover, Western blot was used to analyze the expression of NF-E2-related factor 2 (Nrf2), Heme oxygenase-1 (HO-1), B-cell lymphoma-2 (Bcl-2), Bcl-2-Associated X (Bax) and Cysteinyl aspartate-specific proteinase-3 (Cleaved Caspase-3). Results: Compared with blank control group (Con-A1), swimming time of GLP group increased significantly (P<0.01), and swimming time increased with increase of GLP dose. Compared with blank control group (Con-A2), the liver glycogen of GLP low (GLP-L2), medium (GLP-M2) and high (GLP-H2) dose groups increased by 33.55%, 50.73% and 66.16% respectively (P<0.01), muscle glycogen increased by 64.18%, 106.80% and 117.21% respectively (P<0.01), meanwhile the levels of blood lactic acid and blood urea nitrogen decreased by 32.21%, 42.09%, 42.45% and 18.40%, 34.18%, 34.53% respectively. Compared with model group (M-Con3), MDA content in GLP-L3, GLP-M3 and GLP-H3 groups was significantly decreased (P<0.05), while SOD, CAT and GSH-Px were significantly increased (P<0.05). Correlation analysis showed that anti-fatigue indexes of mice had a high correlation with antioxidant enzyme activity indexes. In addition, compared with M-Con3, protein expression levels of Nrf2, HO-1, and Bcl-2 in GLP-L3, GLP-M3, and GLP-H3 groups were significantly increased (P<0.01), while protein expression levels of Bax and Cleaved caspase-3 were significantly decreased (P<0.01). Conclusion: GLP had significant anti-exercise fatigue effect, and its protective effect on the myocardial tissue of mice might be related to improving the antioxidant capacity of myocardial cells, activating Nrf2/ARE signaling pathway and inhibiting the apoptosis of myocardial cells.