The Effects Of EGCG On The Proliferation, Differentiation And Lipolysis Of Porcine Preadipocytes

At the cellular level,growth of adipose tissue results from both proliferation and differentiation of adipocyte precursor cells,and subsequent enlargement of the mature fat cells. Adipocyte triglyceride(TG) accumulation increased the volume of adipocyte. Changing in the adipocyte mass are mostly due to changes in the metabolic capacities of constitutive adipocyte. Adipocye TG decreases due to the process of lipolysis.The present study examined the influence of epigallocatechin-3-gallate (EGCG) treatment on preadipocyte proliferation and expression lipolysis-related genes mRNA levels in porcine adipose tissue stromal-vascular cell culture from 3～7 day old pigs. The effect of EGCG on the proliferation of porcine preadipocytes were tested by the method of MTT colorimetry. The results show that 100 and 200μmol/L EGCG inhibits the proliferation of preadipocytes and the effects reinforce with the raise of EGCG concentrations. But the lowest concentration of EGCG(5μmol/L),no significant decrease of preadipocyte proliferation as the results. Conparing with porcine preadipocyte, the concentration of EGCG( 5～100μmol/L), can inhibite of rats preadipocyte proliferation and the effects reinforce with the raise of EGCG concentrations.The effect of EGCG on the differentiation of preadipocyte were examined by the quantitation of Oil Red O staining. At the loweat concentration of EGCG(5μmol/L),no effects on differentiation of preadipoxytes. However, 100 and 200μmol/L have significant inhibited effects on this process. The effect of EGCG on the TG accumulate in adipocyte were examined by the quantitation of TG content. The results show that 100 and 200μmol/L EGCG decreased the TG of adipocytes and the effects reinforce with the raise of EGCG concentrations. To investigate the inhibitory mechanism of EGCG during differentiation process,the expression of PPARγ2 and C/EBPαwere examined. The results showing that 200μmol/L EGCG down-regulation of PPARγ2 and C/EBPαduring the early to middle stages of differentiation . The effect of EGCG on adipocye lipolysis was tested by glyerol release quantitation. The results show that 100 and 200μmol/L EGCG increased the glyerol release quantitation of adipocytes and the effects reinforce with the raise of EGCG concentrations. The mRNA levels of lipolysis gene TGH was no influced by EGCG treatmemts. EGCG markedly decreased expression levels of HSL mRNA in the concentration of 200μmol/L in primary cultured...