Inhibitory activity of diacylglycerol acyltransferase (DGAT) and microsomal triglyceride transfer protein (MTP) by the flavonoid, taxifolin, in HepG2 cells: potential role in the regulation of apolipoprotein B secretion
Abstract
The purpose of the present study was to examine the role of taxifolin, a plant flavonoid, on several aspects involving apolipoprotein B (apoB) secretion and triglyceride (TG) availability in HepG2 cells. Taxifolin was shown by ELISA to markedly reduce apoB secretion under basal and lipid-rich conditions up to 63% at 200 micromol/L. As to the mechanism underlying this effect, we examined whether taxifolin exerted its effect by limiting TG availability in the microsomal lumen essential for lipoprotein assembly. Taxifolin was shown to inhibit microsomal TG synthesis by 37% and its subsequent transfer into the lumen (-26%). The reduction in synthesis was due to a decrease in diacylglycerol acyltransferase (DGAT) activity (-35%). The effect on DGAT activity was found to be non-competitive and non-transcriptional in nature. Both DGAT-1 and DGAT-2 mRNA expression remained essentially unchanged suggesting the point of regulation may be at the post-transcriptional level. Evidence is accumulating that microsomal triglyceride transfer protein (MTP) is also involved in determining the amount of lumenal TG available for lipoprotein assembly and secretion. Taxifolin was shown to inhibit this enzyme by 41%. Whether the reduction in TG accumul...Continue Reading
References
Citations
Related Concepts
Related Feeds
Adrenocortical Carcinoma
Hepatocellular carcinoma is the most common type of primary liver cancer and frequently occurs in individuals with chronic liver diseases like cirrhosis. Here is the latest research.
Carcinoma, Hepatocellular
Hepatocellular Carcinoma is a malignant cancer in liver epithelial cells. Discover the latest research on Hepatocellular Carcinoma here.
ApoE, Lipids & Cholesterol
Serum cholesterol, triglycerides, apolipoprotein B (APOB)-containing lipoproteins (very low-density lipoprotein (VLDL), immediate-density lipoprotein (IDL), and low-density lipoprotein (LDL), lipoprotein A (LPA)) and the total cholesterol/high-density lipoprotein (HDL) cholesterol ratio are all connected in diseases. Here is the latest research.