Effects Of EGCG, ECG And GCG From Tea On Melanogenesis In B16F10 Cells And Its Mechanism

For women,healthy white skin is the most ideal state,and the content and distribution of melanin in the skin thas a great influence on the color is skin.The melanin in the skin mainly produced by melanocytes in the basal layer of the epidermis.Tyrosinase activity of melanocytes will be activated after UV irradiation and the formation of melanin increased,then the color of skin becomes darker and darker.With the development and maturity of the cosmetics industry,natural plant extracts have been studied extensively in medicine and cosmetics industry because of their good whitening effect and good safety.Tea is a health food with health function and prevention of human diseases,which contains a wide range of biologically active ingredients.The current research on whitening effect of tea extract mostly concentrated in the study of inhibitory effect on the enzyme activity in vitro.There are few reports on cells cultured in vitro.Only a few experiments of TFs and EGCG on whitening effect is explored,and the Whitening mechanism of ECG and GCG only studied inhibition ofmushroom tyrosinase activity in vitro abroad.It has not been reported that inhibition of melanogenesis and tyrosinase activity in vivo.In this paper,based on the-MSH signal pathway,B16F10 melanoma cells were used as the tested cells,and the effects of tea catechins EGCG,ECG and GCG on melanogenesis were studied.The main results of this paper are as follows:1.Inhibitory effects of EGCG,ECG and GCG on melanogenesis in B16F10 cellsCells were treated with different concentrations of GCG,ECG,EGCG and Arbutin,then the cell morphology was observed under an inverted microscope,the proliferation rate of B16 cells was determined by MTT method,the tyrosinase activity was detected with L-DOPA as substrate,and the melanin synthesis was measured by NaOH-lysis.The results showed that the effects of EGCG,ECG and GCG on the morphology of B16F10 cells showed that the number of cells decreased gradually with the increase of concentration,and the cell growth was inhibited obviously.EGCG,ECG and GCG on B16F10 cell proliferation,tyrosinase activity and melanin formation were inhibited(p<0.05),and the inhibition increased with the increase of the concentration.And the effect of ECG is best,the effect of EGCG is the second and is superior to GCG,which were all better than that of Arbutin.2.EGCG,ECG and GCG down regulated the expression of melanogenesis related genesThe relative expression of MITF、TYR、TRP-1、TRP-2 were detected by PCR.The results showed that,compared with the control group,the expressions of MITF,TYR,TRP-1and TRP-2 were down regulated by EGCG,ECG and GCG,and the down-regulation of MITF gene was the most obvious(p<0.01).The expression of MITF in B16F10 cells treated with EGCG concentration of 60μg·mL~-11 was down regulated compared with that of the control group,while the expression of TYR was down regulated by ECG in the cells(p<0.01).3.EGCG,ECG,GCG reduced the level of cAMP in the B16F10 cells and down regulated the expression of melanin production related proteinsThe use of cAMP E-lisa kit to detect the cAMP level in B16F10 cells,using Western-blot technology to detect EGCG,ECG,GCG and arbutin binding protein of B16F10cells in adenosine phosphate CREB1,p-CREB1,MITF,TYR,TRP-1,TRP-2 The results showed that EGCG,ECG and GCG significantly reduced the level of cAMP in the B16F10cells(p<0.01).Compared with the control group,the expression of CREB1,p-CREB1,MITF,TYR,TRP-1,TRP-2 protein was significantly down regulated by EGCG,ECG and GCG,and there was significant difference(p<0.01).