0261 Hao Ling pu-erh tea attenuates lipid accumulation in primary culture rat hepatocytes

AimTea is one of the most consumed beverages in the world and its healthpromoting effects have been widely investigated.Lipid-lowering effects of pu-erh tea have attracted growing interest.The importance of liver in lipid metabolism prompted us to investigate the lipid-lowering properties of pu-erh tea in rat primary culture hepatocytes.We tested the effect of a Hao Ling pu-erh tea extract (HLPT) and one of the major components of tea as Epigallocatechin-3-gallate (EGCG) which is largely recognized as a hypolipidemic molecule.MethodsHLPT: an infusion of Hao Ling pu-erh tea was lyophilized and quantified for its composition in catechins by LC-MS. 24h after seeding on collagen, rat hepatocytes in primary culture were treated for 24h with various concentrations of HLPT(100,200,400,600μg/ml) and EGCG(30,100uM) and compared to CyclosporinA (hyperlipidemic reference) and Clofibrate (hypolipidemic drug used in human)(n=3 in triplicate).Lipid droplet accumulation was measured by LipidTox staining and evaluated by fluorescence microscopy on an ArrayScanXTI high Content Analysis Reader(Cellomics Inc.).ResultsWe found that HLPT significantly prevented hepatocyte lipid accumulation (−56%) and in the same proportion to Clofibrate.EGCG also significantly attenuated lipid accumulation (−19%) but less than HLPT.ConclusionThe main result of this study was to point out the major implication of liver cells in the hypolipidemic effects of HLPT.Moreover, we have shown here that this effect was partly due to the EGCG, well known for its antioxidant effects.However as we reported here that HLPT has a higher hypolipidemic effect than EGCG alone, which means that EGCG acts in synergy with other HLPT components such as theaflavins but this hypothesis has to be confirmed in further experiments.In future, the variation of expression of genes involved in lipid metabolism (THRSP, LXR, PPar-α) by qPCR induced by HLPT will allow us to improve the understanding of the effect induced by HLPT