Emerging data suggest that cocrystal of two compounds may have a different pharmacological effect from two compounds alone or their physical combination. Glimepiride (Gli) and metformin (Met) are two types of anti-diabetic drugs. Previously we generated the glimepiride/metformin cocrystal (GM). In this study, we evaluated the anti-diabetic effects of GM and explored the underlying mechanisms. Our result showed that GM reduced the blood glucose and HbA1c levels in db/db mice, and low doses of GM can achieve the hypoglycemic effect as Gli or Met alone, and high dose of GM was better than Gli and Met alone in improving the pathological changes of liver. In vivo studies showed that GM activated AMPK and STAT3 signaling, downregulated TXNIP expression and upregulated MaFA expression. Moreover, GM promoted the secretion of insulin in pancreas of db/db mice and in high glucose-treated INS-1 and MIN-6 cells. Together, GM possesses slightly better anti-diabetic effects than Met or Gli alone in db/db mice, and the mechanism of GM protecting β-cell dysfunction induced by glucotoxicity may be associated with activation of the AMPK/TXNIP/MaFA pathway.
Type 2 diabetes mellitus (T2DM) is a common and multiple endocrine metabolic disease. When pancreatic β cell in case of dysfunction, the synthesis and secretion of insulin are reduced. This study is to explore the effect of cordycepin (the molecular formula C 10 H 13 N 5 O 3 ), a natural adenosine isolated from Cordyceps militaris , on high glucose/lipid-induced glucotoxicity and lipotoxicity in INS-1 cells. Our results showed that cordycepin improved cell viability, improved cell energy metabolism and promoted insulin synthesis and secretion. The mechanism may be related to that cordycepin reduces intracellular reactive oxygen species (ROS), increases ATP content in cells, causes membrane depolarization and balances the steady state of Ca 2+ concentration, cordycepin inhibits cell apoptosis, which may be related to the downregulation of proteins level of c-Jun N-terminal kinases (JNK) phosphorylation, cytochrome c (Cyt-c), Cleaved Capase-3, the mRNA level of JNK, Cyt-c, Capase-3 and upregulation of proteins/mRNA level of pancreatic and duodenal homeobox factor-1 (PDX-1). These results suggest that cordycepin can inhibit cell apoptosis and protect cell number by downregulating ROS/JNK mitochondrial apoptosis pathway under high glucose/lipid environment, thereby improving the function of pancreatic islet cells, providing a theoretical basis for the related research on the prevention and control of cordycepin on T2DM.