Effects Of Pomegranate Peel Polyphenols On Cholesterol Synthesis And Its Molecular Mechanism In Hepatic Cell

Pomegranate peel polyphenols are important physiologically active ingredients in the pomegranate, which has anti-oxidation, anti-cancer, anti-bacterial, lowering blood pressure and other biological functions. In this paper, ellagic acid, punicalagin and purified pomegranate polyphenols were treat as test substances, adult liver cells L-02as the research object, which cultured in vitro normal, using oil red O staining the lipid droplets in the liver cells, qRT-PCR analysis of the expression levels about HMGCR mRNA, SE mRNA, LDLR mRNA and SREBP-2mRNA in hepatic cholesterol synthesis, explore pomegranate peel polyphenols and its main component of liver cells cholesterol synthesis and its molecular mechanism.The main results are as follows:(1) Established the model of hepatocyte steaosis:lipid droplets in steatotic hepatocytes were observed by oil red O staining statutory, and the content of hepatic lipases in supernatant were measured by kits. The results show that, the adult liver L-02cells cultured with50%calf serum for48h, steatotic hepatocytes model was established, a significant increase in the number of intracellular lipid droplets, elevated transaminase activity in the cell culture medium.(2) Determined the safe concentration of the pomegranate peel polyphenol in treatment and prevention by MTT:0to100μg/mL.(3) Preliminary determined the effects of pomegranate peel polyphenols on cholesterol synthesis and its molecular mechanism:①Pomegranate ellagic acid, punicalagin, pomegranate polyphenols are able to reduce intracellular lipid droplets. Compared with the treatment group and prevention group, the number of lipid droplets in the prevention group is less than the treatment group in the liver cells, which explain pomegranate peel polyphenols get better effect on cholesterol-lowering in the prevention. ②The qRT-PCR results showed that, compared with the normal group, three reage nts of pomegranate peel polyphenols could reduce the expression regulation of choleste rol synthesis key enzymes genes to a low level, and obviously up-regulate the expressio n of LDLR mRNA and SREBP-2mRNA. In the treatment group, the strength of the reg ulation function on the expression of HMGCR mRNA was:punicalagin> pomegranate peel polyphenols purified> pomegranate ellagic acid, the strength of the regulation func tion on the expression of SE mRNA was:pomegranate peel polyphenols purified> puni calagin> pomegranate ellagic acid, the strength of the regulation function on the expres sion of LDLR mRNA and SREBP-2mRNA was pomegranate ellagic acid> pomegrana te peel polyphenols purified> punicalagin. In the prevention group, the strength of the r egulation function on the expression of HMGCR mRNA and SE mRNA were showed a s follows:pomegranate ellagic acid> pomegranate peel polyphenols purified> punicala gin, the strength of the regulation function on the expression of LDLR mRNA and SRE BP-2mRNA were showed as follows:pomegranate ellagic acid> pomegranate peel pol yphenols purified> punicalagin. The results showed that three of reagents pomegranate peel polyphenols could reduce the expression regulation of cholesterol synthesis of key enzyme below the normal group and reduced cholesterol synthesis. Besides, SREBP-2a nd genes that control the production of LDLR were up-regulated by the pomegranate pe el polyphenols, and the ability that hepatic cells eliminate cholesterin were enhanced. In sum, the prevention group was better than the treatment group in the control of the com position and elimination of cholesterin in hepatic cells.