The polyphenol PGG enhances expression of SR-BI and ABCA1 in J774 and THP-1 macrophages

- PGG induced expression of SR-BI and ABCA1 in J774 and THP-1 macrophages.
- PGG reversed the ox-LDL down-regulated expression of SR-BI and ABCA1 in macrophages.
- PGG reversed the ox-LDL downregulated cholesterol efflux.
- PGG induced reverse cholesterol transport by influencing expression of key proteins.
- PGG represents a novel candidate for prevention and treatment of atherosclerosis.

ObjectivesAtherosclerosis is the major cause of cardiovascular disease. Epidemiological studies showed that the plasma concentration of high-density lipoprotein (HDL) cholesterol level is inversely related to the incidence of atherosclerosis probably due to its role in reverse cholesterol transport. 1,2,3,4, 6-penta-O-galloyl-β-d-glucose (PGG) is a prototypical gallotannin and the central compound in the biosynthetic pathway of hydrolysable tannin. PGG is highly enriched in a number of medicinal herbals. Several in vitro and in vivo studies have shown PGG can influence parameters and processes known to be involved in the development of atherosclerosis. The aim of this study was to investigate the influences of PGG on parameters of reverse cholesterol transport.Methods and resultsWe showed that PGG not only induced expression of SR-BI and ABCA1 in J774 and THP-1 macrophages, but was able to reverse the ox-LDL down-regulated expression of SR-BI and ABCA1 in these cells. Additionally, PGG was able to reverse the ox-LDL downregulated cholesterol efflux from cholesterol laden macrophages.ConclusionIn summary, our data are suggesting that PGG is able to induce reverse cholesterol transport by influencing expression of key proteins of this pathway. We, therefore, suggest that PGG may represent a novel candidate for prevention and treatment of atherosclerosis in humans.

PGG not only induced expression of SR-BI and ABCA1 in J774 and THP-1 macrophages, but also was able to reverse the ox-LDL down-regulated expression of SR-BI and ABCA1 in these cells. The blue arrows mean the effect of ox-LDL. The red arrows mean the effect of PGG.90