Effects Of Quercetin On The Expresion Of Microsomal Triglyceride Transfer Protein And Apoprotein B In Human Hepatocytes.

Objectives: To observe the effects of quercetin on triglyceride levels , and the expression of apoprotein B(apoB) and mirosomal triglyceride transfer protein(MTP) levels in human HL-7702 steatosis hepatocytes. To study the pathogenesis of steatosis hepatocytes and the prevent effects of quercetin.Methods: Be used HL-7702 hepatocytes of normal human as study objects.and the hepatocytes were under fatty change after being exposed to RPMI-1640 complete medium with 10% (V/V) fetal bovine serum plus 10% (V/V) medical fat emulsion injection for 24 hours . we observed the cellular morphology and the formation of lipid droplets in these cells by oil red O staining, and detected the intracellular amount of triglyceride levels through high performance liquid chromatography (HPLC), Then we detected the ApoB and MTP mRNAs'expression of these hepatocytes by the semiquantitative RT- PCR. These hepatocytes were divided into 7 groups: the first group were normal hepatocytes; the second group were fatty changed hepatocytes; from group 3 to group 5, different amount of quercetin was added to those fatty changed hepatocytes to make the concentration of quercetin to be 20μmol/L,40μmol/L,80μmol/L respectively; Group 6 was the positive control group, i.e Gemfibrozil was added to those fatty changed hepatocytes to make the concentration to be 40μmol/L;In group 7 quercetin was added to the normal hepatocytes to make the concentration to be 40μmol/L. All these groups were incubated for another 24 hours,. We observed the cellular morphology and the formation of lipid droplets and detected the intracellular amount of triglyceride levels in these cells, and we detected the ApoB and MTP mRNAs'expression of these hepatocytes .Then we exposed the fatty changed cells to quercetin at the concentration of 40μmol/L for 12h,24h and 48h respectively, and we observed the cellular morphology and the formation of lipid droplets and detected the intracellular amount of triglyceride levels in these cells, and we detected the ApoB and MTP mRNAs'expression of these hepatocytes. All experimental datas were expressed as±s, All statistical analyses were performed by using the SPSS13.0 software. A P value of <0.05 was considered to be of statistical significance.Results: Be exposed normal hepatocytes to RPMI-1640 complete medium with 10% (V/V) fetal bovine serum plus 10% (V/V) medical fat emulsion injection for 24 hours , By Inverted microscope we could find out numerous lipid droplets in the cytolymph of these cells ,which could be dyed to be red by oil red O. what's more intracellular TG level increased dramatically through measurement of HPLC(P﹤0.001). Then we exposed the steatosis hepatocytes to various concentrations of quercetin for 24 hours. By oil red O staining the result indicated that the intracellular lipid droplets of steatosis hepatocytes were much less than before, and quercetin decreased the intracellular TG levels of steatosis hepatocytes in a dose-dependent manner which could be detected by HPLC.What's more, quercetin enhanced the expression of apoB and MTP in a dose-dependent manner which could be detected by the semiquantitative RT- PCR; Then be exposed the steatosis hepatocytes to quercetin of 40μmol/L for 12h,24h and 48h, the result indicated that quercetin decreased the intracellular TG levels of steatosis hepatocytes and induced the up-regulated expression of apoB and MTP in a time-dependent manner .Conclusions:1. Quercetin may decrease the content of intracellular trigelyceride in the human HL-7702 steatosis hepatocytes.2. Quercetin may enhance the mRNAs'expression of apoB and MTP.