Effect of pomegranate peel polyphenols on regulation pathways of cholesterol in hepatic cell

This paper was aimed to study the effects of pomegranate peel polyphenols on lipid droplet formation of hepatocyte and the expression levels of cholesterol synthesis enzyme gene and low density lipoprotein receptor gene. Pomegranate peel polyphenols(PPPs),punicalagin(PC) and pomegranate ellagic acid(EA)were used as test substances,L-02 human hepatocytes were choosen as experimental cell. The lipid droplets in human hepatocytes were assessed by oil red O staining,and the expression levels of HMGCR m RNA,SE m RNA,low density lipoprotein receptor gene LDLR m RNA and its upstream gene SREBP-2 m RNA was analyzed by RT-PCR. The results showed that these three test substances could reduce the intracellular lipid droplets,and the EA showed better effect. Compared with the model group,PPPs could significantly decrease(p<0.01) cholesterol. Moreover,compared with the normal group,HMGCR m RNA and SE m RNA were downregulated,whereas LDLR m RNA and SREBP-2 m RNA were up-regulated by pomegranate peel polyphenols.The possible mechanism of regulating cholesterol balance by PPPs and its mian component PC and EA in hepatic cells was via the downregulating cholesterol synthesis enzyme gene expression and upregulating the LDLR gene expression.