苦荞多酚对HepG2细胞糖代谢功能的影响

Effects of Tartary Buckwheat Polyphenols on the Glucose Metabolism of HepG2 Cells

摘要:

为了探究苦荞多酚对胰岛素抵抗HepG2细胞糖代谢功能的影响，作者采用葡萄糖胺（glucosamine，GluN）诱导HepG2细胞构建胰岛素抵抗模型，并通过纯化后的苦荞多酚干预，明确苦荞多酚对胰岛素抵抗的改善作用及其潜在作用机制。结果表明，苦荞多酚能显著改善胰岛素抵抗HepG2细胞的葡萄糖消耗水平，效果与阳性药物二甲双胍相当。在氧化应激方面，苦荞多酚能显著增强超氧化物歧化酶（superoxide dismutase，SOD）、过氧化氢酶（catalase，CAT）、谷胱甘肽过氧化物酶（glutathione peroxidase，GSH-Px）的酶活力，抑制脂质过氧化产物丙二醛产生，保护胰岛β细胞免受自由基损害。在糖异生途径中，苦荞多酚的干预使葡萄糖-6-磷酸酶（gluose-6-phosphatase，G-6-P）和磷酸烯醇式丙酮酸羧激酶（phosphoenolpyruvate carboxykinase，PEPCK）的酶活力降至模型组的24.56%和50.69%，同时调控G-6-P和PEPCK的FOXO1基因表达量，比模型组下调了49.66%。在糖原合成方面，苦荞多酚能促使胰岛素抵抗HepG2细胞糖原合成量增加了74.55%，同时能够显著下调GSK-3β基因的表达量。因此，苦荞多酚表现出良好的改善氧化应激和肝糖代谢能力。

Abstract:

To investigate the effect of tartary buckwheat polyphenols on glucose metabolism in insulin resistant HepG2 cells, a model of IR was established by inducing HepG2 cells with glucosamine (GluN), then intervened with purified tartary buckwheat polyphenols to clarify the improvement effect and potential mechanism of tartary buckwheat polyphenols on insulin resistance. The results showed that tartary buckwheat polyphenols significantly improved the glucose consumption level of insulin resistant HepG2 cells, which was equivalent to the positive control drug, metformin. In terms of improving oxidative stress, tartary buckwheat polyphenols significantly enhanced the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), inhibited the production of malondialdehyde, and protected pancreatic β-cells from free radical damage. In the gluconeogenic pathway, the intervention of tartary buckwheat polyphenols resulted in a reduction to 24.56% and 50.69% of glucose-6-phosphatase (G-6-P) and phosphoenolpyruvate carboxyl kinase (PEPCK) activity, respectively, compared to the model group. Concurrently the expression of FOXO1 gene, which regulates G-6-P and PEPCK, was down regulated by 49.66% compared to the model group. In terms of glycogen synthesis, tartary buckwheat polyphenols promoted a 74.55% increase in glycogen synthesis in insulin resistant HepG2 cells, while significantly downregulating GSK-3β gene expression. Overall, tartary buckwheat polyphenols showed a strong potential to improve oxidative stress and hepatic glucose metabolism.