The prevalence of
metabolic diseases has risen globally in parallel with the
obesity epidemic over the past few decades.
Green tea has been reported to have metabolically beneficial effects on
obesity; however, the mechanism by which
green tea regulates lipid metabolism is not clearly understood. Male c57BL/6 mice were fed a normal chow diet, a high-fat diet (HFD), or an HFD supplemented with various doses of
epigallocatechin gallate-rich
green tea extract (GTE) for 12 weeks. GTE supplementation reduced
body weight gain, prevented hepatic fat accumulation, decreased
hypertriglyceridemia, and improved
hyperglycemia and
insulin resistance in HFD-fed mice. The underlying mechanisms of these beneficial effects of GTE might involve the upregulation of
sirtuin 1 and
AMP activated protein kinase (AMPK) and the downregulation of
enzymes related to de novo lipogenesis. Consistent with the in vivo findings, GTE increased the expression and activity of
sirtuin 1, enhanced the binding of
sirtuin 1 to liver
kinase B1 (LKB1) and subsequent deacetylation of LKB1, and reduced
triglyceride accumulation in HepG2 cells. These results suggest the possible therapeutic potential of dietary
epigallocatechin gallate-rich GTE supplementation for preventing the development and progression of hepatic steatosis and
obesity.