Inflammation and oxidative stress play crucial roles in the etiology of type 2 diabetes mellitus. In this study, we examined the anti-diabetic effects of triterpenoid saponins extracted from Stauntonia chinensison stimulating glucose uptake by insulin-resistant human HepG2 cells. The results showed that saponin 6 significantly increased glucose uptake and glucose catabolism. Saponin 6 also enhanced the phosphorylation of AMP-activated protein kinase (AMPK) and activated the insulin receptor (IR)/insulin receptor substrate-1 (IRS-1)/phosphoinositide 3-kinase (PI3K)/Akt pathway. Therefore, our results suggest that saponins from S. chinensis improve glucose uptake and catabolism in hepatic cells by stimulating the AMPK and the IR/IRS-1/PI3K/Akt signaling pathways. The results also imply that saponins from S. chinensis can enhance glucose uptake and insulin sensitivity, representing a promising treatment for type 2 diabetes mellitus.
16 October 2018 in Journal of Cellular and Molecular Medicine
Stauntonia chinensis DC. has been utilised as a traditional herbal medicine for its anti‐hyperglycemic characteristic, which has been associated with triterpene saponins. The goal of the current evaluation was to examine hypoglycemic activity and affiliated mechanism of total saponins from S. chinensis. The chemical composition was analysed by HPLC‐ESI‐MS/MS. The fasting blood glucose, oral glucose tolerance test, insulin tolerance test, insulin and glycogen levels of type 2 diabetic db/db mice administered total saponins were quantified to determine the hypoglycemic effects. The serum lipid profiles were assessed to determine the hypolipidemic effects. Western blotting was used to quantify the protein levels of insulin receptor substrates (IRS)‐1/PI3K/AKT, AMPK/ACC and GLUT4. Twenty triterpene saponins were identified from the total saponins, which exhibited hypoglycemic activities and modulated hyperlipidemia that was associated with type 2 diabetes. The hypoglycemic effects were partly due to the activation of GLUT4, which is regulated by IRS‐1/PI3K/AKT. The activation of the AMPK/ACC signalling pathway may be responsible for the hypolipidemic activity. This study revealed that total saponins from S. chinensis have significant hypoglycemic and hypolipidemic activity in diabetic db/db mice, indicating that these may be utilised in the development of saponins based on S. chinensis for the treatment of type 2 diabetes.
By using a traceless oxidizing directing group, a Rh(III)-catalyzed C–H alkylation of N-phenoxyacetamides with allylic alcohols has been developed under mild and redox-neutral conditions. This transformation provided an efficient methodology for the synthesis of valuable β-aryl ketones in good to excellent yields.