Study on the Interaction between Silibinin and Neuraminidase.

BACKGROUND: Neuraminidase is a pathogenic protein of the avian influenza virus. Previous studies have shown that silibinin has the potential to inhibit neuraminidase activity. OBJECTIVE: This study aims to explore the interaction between silibinin and neuraminidase and the effect of silibinin on the structure and activity of neuraminidase. METHODS: In this study, two-dimensional fluorescence spectrum, three-dimensional fluorescence spectrometry, Uv-vis spectroscopy, and circular dichroism analysis were used. RESULTS: Silibinin alters the secondary structure of neuraminidase and inhibits the activity of neuraminidase. CONCLUSION: Silibinin can interact with neuraminidase and inhibit its activity.

The Discovery and Development of Glucagon-Like Peptide-1 Receptor Agonists.

Diabetes mellitus has become a serious life-threatening disease. As one of the new drugs for the treatment of diabetes, GLP-1 receptor agonists have attracted a lot of attention. Compared with traditional hypoglycemic drugs, GLP-1 receptor agonists have good safety and tolerability. To a certain extent, they overcome the problem of the short half-life of natural GLP-1 in vivo and can exist stably in patients for a long time, achieving good results in the treatment of diabetes, as well as improving the symptoms of some complications. The GLP-1 receptor agonists in the market are all peptide drugs. Compared with peptide drugs, small molecule agonists have the advantages of low cost and oral administration. In this article, we review the recent research progress of GLP-1 receptor agonists.

Loureirin B promotes insulin secretion through GLP-1R and AKT/PDX1 pathways.

Loureirin B (LB), a natural product derived from Sanguis draconis, has hypoglycemic effects in diabetic mice. However, there are no studies on how LB lowers blood glucose. In this study, we first treated a diabetic model in mice with LB, and the results showed that LB lowered blood glucose and alleviated islet damage in mice. Next, Ins-1 cells were treated with LB. The results showed that LB could promote cell proliferation and reduce apoptosis of Ins-1 cells. Loureirin B (LB), a natural product derived from Sanguis draconis, has hypoglycemic effects in diabetic mice. However, there are no studies on how LB lowers blood glucose. In this study, we first treated mice with LB in a diabetic model and showed that LB lowered blood glucose and reduced islet damage in mice. Next, Ins-1 cells were treated with LB. The results showed that LB could promote cell proliferation and reduce apoptosis of Ins-1 cells. Further, after inhibiting GLP-1R activity, the results showed that LB promoted insulin secretion, Ins-1 cell proliferation and reduced Ins-1 cell apoptosis with reduced effect, indicating that LB achieved the above effects by activating GLP-1Ra. Meanwhile, cellular cAMP levels increased when GLP-1R was overexpressed, which also demonstrated the interaction between LB and GLP-1R. Subsequently, the effect of LB on cellular potassium channels was examined by membrane clamp, and the results showed that LB increased intracellular Ca2+ concentration and stimulated insulin secretion by activating GLP-1R and thus closing the ATP-sensitive potassium channels. On the other hand, the activation effect of LB on AKT/PDX1 signaling pathway was verified.

Loureirin B attenuates insulin resistance in HepG2 cells by regulating gluconeogenesis signaling pathway.

Insulin resistance (IR) is the main cause of type 2 diabetes. The liver is the organ where insulin is secreted from the pancreas, and it regulates the storage and release of glucose according to the body's demand. Althouth Loureirin B (LB) has been reported to promote insulin secretion and decrease blood glucose, the effects of LB on glucose metabolism in the liver and the mechanism is still unclear. Different concentrations of LB were applied to treat on insulin resistance model (IR-HepG2) cells. The research results showed that LB inhibited the production of ROS (Reactive oxygen species) in IR-HepG2 cells, promoted the phosphorylation of AKT, down-regulated the expression of FoxO1, and up-regulated the expression of IRS1 and GLUT4. In addition, LB also down regulated the glucose metabolism related genes PEPCK and GSK3ß. The glucose uptake, consumption and glycogen content were increased. Moreover, LB-treated diabetic mice also showed hypoglycaemic effects. In summary, LB may ameliorate type 2 diabetes by preventing the inactivation of IRS1/AKT pathway in IR-HepG2 cells, increasing insulin sensitivity, and regulating glucose uptake and production.