Cyclocarya paliurus extract attenuates hepatic lipid deposition in HepG2 cells by the lipophagy pathway

作者：Wanwei Yang, Cuihua Jiang, Zhiguo Wang, Jian Zhang, Xiaodong Mao, Guofang Chen, Xiaoming Yao, Chao Liu · 发表于：Pharmaceutical Biology · 年份：2020 · DOI：10.1080/13880209.2020.1803365 · 被引用次数：10 · 研究领域：Polysaccharides and Plant Cell Walls、Natural Compound Pharmacology Studies、Autophagy in Disease and Therapy

Context Cyclocarya paliurus (CP) (Batal.) Iljinsk (Cyclocaryaceae), a plant native to China, is the sole species in the genus Cyclocarya. Its leaves have been widely used as a remedy for hyperlipidaemia in traditional folk medicine. However, the mechanism underlying CP-induced lipolysis, especially in the liver, has not been entirely elucidated.Objective This study investigates the effect of CP ethanol extract (CPE) on hepatic steatosis and the underlying molecular mechanisms involved.Materials and methods The effect of CPE at concentrations of 0, 6.25, 12.5, 25, 50, and 100 μg/mL on the viability of HepG2 cells was examined using the cell counting kit-8 (CCK-8) assay after incubation for 24 h. CPE-induced changes in intracellular lipid content were assessed by measuring the absorbance of oil red O staining at 520 nm, and the possible underlying mechanisms were further studied using quantitative reverse transcription polymerase chain reaction (RT-qPCR) analysis, western blotting, immunofluorescence studies and transmission electron microscopy.Results The half-maximal inhibitory concentration (IC50) of CPE in HepG2 cells was 97.27 μg/mL. Treatment with 50 μg/mL CPE increased lipid clearance, which was associated with increased autophagy in HepG2 cells. CPE-induced autophagy involved downregulation of phosphorylation level of mammalian target of rapamycin (0.87 ± 0.08 vs. 1.31 ± 0.10). Fluorescent double staining and electron microscopy images showed lipid deposits within autol...