Green tea prepared with daily infusion style prevents non-alcoholic fatty liver disease by targeting intestinal lipid absorption, hepatic lipid metabolism and gut microbiota composition

Abstract

Non-alcoholic fatty liver disease (NAFLD) is closely linked to metabolic disorders and is characterized by excess fat accumulation in the liver. Although drinking green tea has been reported to have various health benefits, the impacts and mechanisms of green tea infused by the daily style on preventing NAFLD progression remain unclear. To address this issue, we first established a human diet-mimicking mice model induced by a Western diet (WD) consisting of high-fat, high-cholesterol and high-refined sugar. Then we supplemented green tea extract (GTE) prepared with the traditional daily infusion style at 0.5% or 1% to investigate the preventive effect on NAFLD. The results revealed that GTE consumption attenuated the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and hepatic triglyceride (TG) content caused by WD. In parallel with this, GTE increased TG excretion in fecal. In vitro pancreatic lipase assay further demonstrated that GTE and catechins, especially gallate catechins, showed strong inhibitory effects on lipase activity. Furthermore, (−)-Epigallocatechin-3-gallate (EGCg), a major bioactive compound of GTE, inhibited hepatic lipogenesis by increasing the level of carnitine palmitoyltransferase I (CPT1) in Hepa 1-6 cells. Finally, 16S rRNA sequencing of gut bacteria revealed that GTE reduced the ratio of p_Firmicutes/p_Bacteroidetes (F/B) increased by WD and modified gut microbiota composition. In summary, daily intake of GTE attenuated WD-induced NAFLD by inhibiting intestinal lipid absorption, modulating hepatic lipid metabolism and regulating gut microbiota composition. These results suggested that daily consumption of green tea infused by the daily style might contribute to preventing NAFLD.