Systemic Perturbations of Key Metabolites in Type 2 Diabetic Rats Treated by Polyphenol Extracts from Litchi chinensis Seeds.

Our previous research obtained Litchi chinensis Sonn. seeds extract (LSE) which showed hypoglycaemic effects on type 2 diabetes (T2D) rats. In order to understand the detailed pathogenesis of diabetes intervened by LSE, the metabonomics strategy was used. As a result, LSE decreased the insulin resistance index and the levels of glucose in urine through elevating the mRNA level of insulin, while decreasing the expression of glucagon to enhance the function of the pancreas. Meanwhile, LSE regulated the glucose and fatty acid metabolisms via increasing the expression of glucose transporter (Glu) 2, Glu4, insulin receptor (IR), and IR substrate-2 (IRS2). LSE effectively restored the impairment of the IRS2/PI3K/Akt/mTOR insulin signaling in the livers. All in all, LSE played a pivotal role in the treatment of T2D through regulation of broad-spectrum metabolic changes and inhibition of the glycogenesis, proteolysis, and lipogenesis in T2D rats.