Cholesterol and bile acid-mediated regulation of autophagy in fatty liver diseases and atherosclerosis

Liver is the major organ that regulates whole body cholesterol metabolism. Disrupted hepatic cholesterol homeostasis contributes to the pathogenesis of nonalcoholic steatohepatitis, dyslipidemia, atherosclerosis, and cardiovascular diseases. Hepatic bile acid synthesis is the major catabolic mechanism for cholesterol elimination from the body. Furthermore, bile acids are signaling molecules that regulate liver metabolism and inflammation. Autophagy is a highly-conserved lysosomal degradation mechanism, which plays an essential role in maintaining cellular integrity and energy homeostasis. In this review, we discuss emerging evidence linking hepatic cholesterol and bile acid metabolism to cellular autophagy activity in hepatocytes and macrophages, and how these interactions may be implicated in the pathogenesis and treatment of fatty liver disease and atherosclerosis.     

Natural products as modulators of the nuclear receptors and metabolic sensors LXR,FXR and RXR

Nuclear receptors (NRs) represent attractive targets for the treatment of metabolic syndrome-related diseases. In addition, natural products are an interesting pool of potential ligands since they have been refined under evolutionary pressure to interact with proteins or other biological targets.This review aims to briefly summarize current basic knowledge regarding the liver X (LXR) and farnesoid X receptors (FXR) that form permissive heterodimers with retinoid X receptors (RXR). Natural product-based ligands for these receptors are summarized and the potential of LXR, FXR and RXR as targets in precision medicine is discussed.