Hypoglycemic Effect of Total Flavonoids from Potentillae Discoloris Herba in Type 2 Diabetic db/db Mice / 中国实验方剂学杂志

ABSTRACT

Objective:The hypoglycemic effects and mechanisms of total flavonoids from Potentillae Discoloris Herba（TFE） on insulin resistance through the phosphatidylinositol-3 kinase （PI3K）/protein kinase B （Akt） signaling pathway in db/db mice were investigated. Method:The 24 db/db mice were randomly divided into four groups， model group， metformin group and TFE 100，400 mg·kg^-1 group respectively. The 6 db/m mice as normal control group. After 4 weeks treatment， the mice were processed and the levels of fasting blood glucose（FBG）， glycated serum protein（GSP），fasting blood insulin（FINS），triglyceride（TG）， total cholesterol（TC）， low density lipoprotein cholesterol （LDL-C），high density lipoprotein cholesterol （HDL-C） in serum were detected. Homeostatic model assessments of insulin resistance（HOMA-IR）were quantified. Hematoxylin-eosin（HE）staining of liver and pancreatic tissues were examined. The expression of IR<italic>β</italic>， IRS-1，PI3K，phosphorylation-PI3K （p-PI3K）， Akt， phosphorylation-Akt（p-Akt） and glucose transporter 4（GLUT4） in livers were assessed by Western blot. Result:Compared with normal group， model group showed liver and pancreas injury. FBG， GSP， TC， TG， LDL-C， FINS and MDA levels in serum were significantly increased （<italic>P</italic><0.01）， HDL-C and SOD levels in serum were significantly decreased （<italic>P</italic><0.05）， liver glycogen content was significantly decreased （<italic>P</italic><0.01）， as well as expression of IR， IRS-1， p-PI3K/PI3K， p-Akt/Akt and GLUT4 protein in liver tissues were significantly decreased （<italic>P</italic><0.01）. Compared with model group， TFE was able to relieve liver and pancreas injury，while the levels of FBG， GSP， TC， TG， FINS and MDA in serum were significantly decreased （<italic>P</italic><0.05）， HDL-C and SOD levels liver were significantly increased （<italic>P</italic><0.05）， liver glycogen content was significantly increased （<italic>P</italic><0.01）， and the expressions of IRS-1， p-PI3K/PI3K， p-Akt/Akt and GLUT4 protein in liver tissues were significantly up-regulated （<italic>P</italic><0.05）. Conclusion:These findings indicate that TFE has the potential to reduce blood sugar and alleviates insulin resistance through the PI3K/Akt signaling pathway in the livers of db/db mice.