Effect of South African Herb Hoodia gordonii on Liver Glucolipid Metabolism and PI3K/Akt/FoxO1 Signalling Pathway in db/db Mice / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo observe the effects of the South African herb Hoodia gordonii （HG） on glucolipid metabolism in diabetic db/db mice and explore the possible mechanisms of HG on the liver of db/db mice based on the phosphoinositide-3 kinase （PI3K）/protein kinase B （Akt）/factor forkhead protein O1 （FoxO1） signaling pathway. MethodA total of 30 db/db mice were randomly divided into five groups according to fasting blood glucose： model group， metformin group （0.195 g·kg-1）， and low dose （0.39 g·kg-1）， medium dose （0.78 g·kg-1）， and high dose （1.56 g·kg-1） HG groups， with six m/m mice in each group， and another six m/m mice were set as normal group. The mice in the normal and model groups were given saline of 9 mL·kg-1 by gavage. Body weight， water intake， and fasting blood glucose of the mice in each group were measured weekly. After six weeks of continuous administration， serum insulin （FINS）， low-density lipoprotein cholesterol （LDL）， total cholesterol （TC）， triglyceride （TG）， alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， urea， and creatinine （CREA） were measured， and liver sections were embedded and stained with hematoxylin-eosin （HE）， periodic acid-Schiff （PAS）， and oil red O. Protein expression of PI3K p85， p-Akt， and p-FoxO1 in liver was detected by immunohistochemistry. The mRNA expression of PI3K， Akt， and FoxO1 in liver tissue was detected by real-time polymerase chain reaction （Real-time PCR）. ResultAfter six weeks of administration intervention， it was found that fasting blood glucose was significantly downregulated in mice in the three HG groups （P<0.05）. The level of islet resistance index was significantly reduced in both the low and medium dose HG groups （P<0.05）. The expression levels of TC， TG， and LDL were reduced in all HG groups （P<0.05， P<0.01）. Pathologically， HG could alleviate hepatocyte steatosis， reduce the volume and content of lipid droplets in liver， and increase the distribution of glycogen granules in liver to some extent in mice. Immunohistochemical assays revealed that PI3K p85 protein expression was significantly increased in the low， medium， and high dose HG groups compared with the model group （P<0.01）. p-Akt protein expression was significantly increased in the medium and high dose HG groups （P<0.05， P<0.01）. p-FoxO1 protein expression was significantly increased in the low， medium， and high dose HG groups （P<0.05， P<0.01）. Compared with the model group， PI3K mRNA was increased in low dose， medium dose， and high dose HG groups （P<0.05）， and Akt mRNA was increased in high dose HG group （P<0.05）. FoxO1 mRNA was decreased in low dose， medium dose， and high dose HG groups （P<0.05）. ConclusionHG can ameliorate the disorder of glucolipid metabolism in db/db mice， which may be related to its activation of the hepatic PI3K/Akt/FoxO1 signaling pathway.