Green tea polyphenols ameliorate non-alcoholic fatty liver disease through upregulating AMPK activation in high fat fed Zucker fatty rats

Abstract

AIMTo investigate protective effects and molecular mechanisms of green tea polyphenols (GTP) on non-alcoholic fatty liver disease (NAFLD) in Zucker fatty (ZF) rats.METHODSMale ZF rats were fed a high-fat diet (HFD) for 2 wk then treated with GTP (200 mg/kg) or saline (5 mL/kg) for 8 wk, with Zucker lean rat as their control. At the end of experiment, serum and liver tissue were collected for measurement of metabolic parameters, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), inflammatory cytokines and hepatic triglyceride and liver histology. Immunoblotting was used to detect phosphorylation of AMP-activated protein kinase (AMPK) acetyl-CoA carboxylase (ACC), and sterol regulatory element-binding protein 1c (SREBP1c).RESULTSGenetically obese ZF rats on a HFD presented with metabolic features of hepatic pathological changes comparable to human with NAFLD. GTP intervention decreased weight gain (10.1%, P = 0.052) and significantly lowered visceral fat (31.0%, P < 0.01). Compared with ZF-controls, GTP treatment significantly reduced fasting serum insulin, glucose and lipids levels. Reduction in serum ALT and AST levels (both P < 0.01) were observed in GTP-treated ZF rats. GTP treatment also attenuated the elevated TNFα and IL-6 in the circulation. The increased hepatic TG accumulation and cytoplasmic lipid droplet were attenuated by GTP treatment, associated with significantly increased expression of AMPK-Thr172 (P < 0.05) and phosphorylated ACC and SREBP1c (both P < 0.05), indicating diminished hepatic lipogenesis and triglycerides out flux from liver in GTP treated rats.CONCLUSIONThe protective effects of GTP against HFD-induced NAFLD in genetically obese ZF rats are positively correlated to reduction in hepatic lipogenesis through upregulating the AMPK pathway.

Anti-obesity and fatty liver-preventing activities of Lonicera�caerulea in high-fat diet-fed mice

“…The equilibrium between lipogenesis and hepatic lipolysis is imperative for the improvement of patients with NAFLD. High-fat diet (HFD)-treated animals exhibit mild obesity and are appropriate for use in the development of preventive agents for metabolic syndromes including NAFLD ( 9 - 11 ). Therefore, an HFD-fed mice model was selected for the detection of the various pharmacological effects of the test material.…”

HER2+ breast cancer cells undergo apoptosis upon exposure to tannic acid released from remodeled cross‐linked collagen type I

“…Polyphenols extracted from grape seeds induce glucose uptake and lipogenesis in differentiation preadipocytes . Green tea polyphenols help promote neurogenesis and liver tissue regeneration . Conversely, epigallocatechin, a component of green tea extract, inhibits stem cell differentiation and adipogenesis .…”

Nutritional applications and beneficial health applications of green tea and l‐theanine in some animal species: A review

“…It is speculated that GTPs directly and indirectly suppress tumour cell proliferation and angiogenesis via human antigen (Hu) R-related pathways in bladder cancer in a mouse model (Matsuo et al, 2017). The protective effects of GTPs against high-fat-diet-induced non-alcoholic fatty liver disease in genetically obese Zucker fatty rats were mediated by a reduction in hepatic lipogenesis through the activation of the AMP-activated protein kinase pathway (Tan et al, 2017). Furthermore, fermented mixed tea containing green tea exhibited a preventive effect against the progression of non-alcoholic steatohepatitis (Omagari et al, 2018) and the combination of selenium and green tea was effective in suppressing colorectal cancer in rats (Hu et al, 2013).…”