Japanese quince (Chaenomeles japonica L.) fruit polyphenolic extract modulates carbohydrate metabolism in HepG2 cells via AMP-activated protein kinase

Abstract

Scope: Type 2 diabetes mellitus is a chronic diet-related disease which has become a prominent health problem of the world and there is a need of research of natural agents with preventive activities against that metabolic disorder and present in food matrixes. Thus the aim of the study was to explore the in vitro activity of Japanese quince fruit polyphenolic extract as modulator of carbohydrates metabolism. Methods and results: The study was designed to investigate the effect of Japanese quince polyphenolic extract on glucose metabolism in human hepatoma HepG2 cell line. Pretreatment of the cells with JQ preparation caused decrease of intracellular ROS generation and influenced mitochondrial membrane polarization which seems to lead to AMPK activation. Further effects observed in HepG2 cells were associated with activation of the enzyme: elevation of glucose uptake and glycogen content, and alleviation of gluconeogenesis through modulation of PEPCK, PTP1B, FOXO1 and GLUT4 mRNA expression. Conclusion: These findings suggest that JQ polyphenols exhibit hypoglycemic effects via modulation of AMPK signaling.