Objectives: We investigated potential antihyperglycemic effects of HM-chromanone (HMC), a homoisoflavonoid isolated from Portulaca oleracea, in mice fed a high-fat diet (HFD).
Methods: Five-week-old male C57BL/6J mice (n = 24) were divided into three groups: controls, mice fed an HFD (11 weeks), and HFD-fed mice receiving HMC supplementation (8 weeks). Various analyses assessed liver and skeletal muscle proteins, pancreatic β-cell histology, blood glucose and HbA1c levels, and homeostatic index of insulin resistance (HOMA-IR).
Results: HMC supplementation significantly reduced fasting blood glucose and postprandial blood glucose levels in HFD-fed mice. HbA1c and serum insulin levels reduced significantly, and HOMA-IR improved. Compensatory β-cell hyperplasia was reduced, and pancreatic β-cell function improved. AMP-activated protein kinase (AMPK) was significantly activated in skeletal muscle and liver tissues. IRS-1tyr612 expression increased significantly. PI3K activation and Akt phosphorylation in skeletal muscles improved insulin signaling. Forkhead box protein O1 phosphorylation increased through hepatic AMPK activation. Phosphoenolpyruvate carboxykinase and glucose-6-phosphatase expression was inhibited. Glycogen synthase kinase 3β phosphorylation increased.
Conclusions: HMC supplementation alleviated hyperglycemia by activating the AMPK and PI3K/Akt pathways in skeletal muscles and the AMPK pathway in the liver of HFD-fed mice.
Keywords: AMPK; HM-chromanone; diabetes mellitus; hyperglycemia; insulin resistance.