Persimmon tannin regulates the expression of genes critical for cholesterol absorption and cholesterol efflux by LXRα independent pathway

Abstract

Persimmon tannin (proanthocyanidins) has been proven to exert significant hypocholesterolaemic effects in a variety of models. However, the regulatory mechanisms of persimmon tannin on cholesterol metabolism have yet to be fully understood. The present study investigated the regulation of persimmon tannin on the expression of genes critical for cholesterol absorption and cholesterol efflux. Our results indicated that persimmon tannin reduced the uptake of 22-NBD-cholesterol and inhibited the accumulation of cholesterol significantly in HepG2 and Caco-2 cell lines. The mRNA and proteins were quantified using real time PCR and western blot, respectively. The expression of SREBP-2 gene, critical for cholesterol synthesis, and NPC1L1 involved in cholesterol absorption were significantly inhibited by persimmon tannin. Moreover, persimmon tannin showed potential in promoting cholesterol efflux through up-regulating mRNA and/or protein levels of ABCA1, ABCG1, SR-BI, CYP7A1 and ABCG5/G8. However, the regulation effects of persimmon tannin on cholesterol homeostasis in both cell lines were LXRα independent.

Keywords

• Persimmon tannin
• Cholesterol homeostasis
• LXRα
• ABCA1
• CYP7A1