A proteoglycan extract from Ganoderma Lucidum protects pancreatic beta-cells against STZ-induced apoptosis

The pancreatic β-cell death or dysfunction induced by oxidative stress plays an important effect on the development and progression of diabetes mellitus. Based on our previous findings, a natural proteoglycan extracted from Ganoderma Lucidum, named FYGL, could treat T2DM in vivo. In this study, we investigated the effects of FYGL on STZ‐induced apoptosis of INS-1 cells and its underlying mechanisms. The results showed that FYGL significantly improved the cell viability and alleviated the apoptosis in STZ‐treated INS‐1 cells. Moreover, FYGL markedly decreased the intracellular ROS accumulation and NO release, and deactivated NF-κB, JNK, and p38 MAPK signaling pathways in STZ-induced INS-1 cells. Furthermore, FYGL improved the insulin secretion through inhibiting the activation of JNK and improving the expression of Pdx-1 in INS-1 cells damaged by STZ. These results indicated that FYGL could protect pancreatic β-cells against apoptosis and dysfunction, and be used as a promising pharmacological medicine for diabetes management.Abbreviations: T2DM: type 2 diabetes mellitus; FYGL: Fudan-Yueyang G. lucidum; ROS: reactive oxygen species; NO: reactive oxygen species; NF-κB: nuclear factor kappa beta; JNK: c-jun N-terminal kinase; MAPK: mitogen-activated protein kinase; Pdx-1: Pancreatic duodenal homeobox 1