SIRT3 and fatty liver disease: The underlying mechanism that theacrine ameliorates high fat diet induced hepatic steatosis in mice involves in SIRT3/AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) pathway, during which the activation of ACC by theacrine depends on the phosphorylation of AMPK, but the activation of SIRT3 by theacrine is independent of the phosphorylation of AMPK (34).