Polyphenol-rich extract of Zhenjiang aromatic vinegar ameliorates high glucose-induced insulin resistance by regulating JNK-IRS-1 and PI3K/Akt signaling pathways

Abstract

Zhenjiang aromatic vinegar is a famous traditional fermented cooking ingredient in China, with multiple nutritional and medicinal applications. Zhenjiang aromatic vinegar extract (100-400 μg/mL) is rich in polyphenols increased the glucose uptake and glucose consumption in high glucose-induced insulin resistant HepG2 (IR-HepG2) cells. Zhenjiang aromatic vinegar extract enhanced glycogen synthesis and attenuated gluconeogenesis by regulating key enzymes in IR-HepG2 cells. In addition, Zhenjiang aromatic vinegar extract ameliorated high glucose-induced IR by inhibiting phosphorylated insulin receptor substrate-1 (IRS-1) expression and activating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in IR-HepG2 cells. Moreover, Zhenjiang aromatic vinegar extract reduced reactive oxygen species generation and phosphorylated c-Jun NH₂ terminal kinase (JNK) expression in IR-HepG2 cells. The attenuation of the high glucose is owned to the PI3K/Akt pathway activation, glycogen synthesis induction and gluconeogenesis suppression in IR-HepG2 cells.

Keywords: HepG2 cells; Insulin resistance; JNK-IRS-1; PI3K/Akt; Polyphenols; Vinegar extract.