Effects and Underlying Mechanisms of Lycium barbarum leaves Flavonoids on Lipid Metabolism in HepG2 Cells

Abstract

The aim of this study was to investigate the impact of Lycium barbarum leaves flavonoids (LBLF) on lipid accumulation in normal and oleic acid-induced HepG2 cells. The experiment was divided into six groups as follows: blank, model, positive control, low-, medium-, and high-dose LBLF. Oil red O staining was performed to assess the aggregation of lipid droplets in each group, and lipid levels and oxidative stress indicators were measured. Finally, real-time polymerase chain reaction (real-time PCR) and Western blot were used to detect the expression of mRNAs and proteins associated with lipid synthesis. The results indicated that LBLF could decrease the increase in the levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), malondialdehyde (MDA) and reactive oxygen species (ROS) induced by oleic acid in HepG2 cells. It also could increase high-density lipoprotein cholesterol (HDL-C), superoxide dismutase (SOD), glutathione, and catalase levels. Additionally, Western blot results suggested that LBLF intervention could up-regulate phosphorylated adenosine 5’-monophosphate (AMP)-activated protein kinase (p-AMPK) and AMPK levels, and down-regulate the protein expression of sterol regulatory element-binding protein 1c(SREBP-1c), peroxisome proliferator-activated receptor γ (PPARγ), and CCAAT enhancer binding protein alpha (CEBPα). Real-time PCR results indicated that LBLF intervention down-regulated the expression of genes such as ACC, FAS, SREBP-1c, SCD-1, PPARγ, and CEBPα. In conclusion, LBLF could partially alleviate lipid metabolism disorder in oleic acid-induced HepG2 cells by regulating the expression levels of lipid synthesis and oxidation-related genes.

Keywords

• lycium barbarum leaves flavonoids; hepg2 cells; lipid metabolism; action mechanism