Evaluation Of Typical Processing Methods Of Teas On Lipid Lowering Activity Based In Mice

The chemical composition determines the biological activity of tea and affected by multiple factors.Among which the processing technology is the main factor to classify six tea types,as well as to the biological activity of teas,therefore,to study the influence of processing technology on biological activity of teas is of great significance.Lipid-lowering activity is one of the most important biological activity of tea,in the present study,we made five types of teas which made from unified fresh tea plant leaf according to the typical tea processing methods,including green tea,white tea,yellow tea,oolong tea and black tea.Using HPLC to analyze the major chemical components,employing high fat diet induced obese C57BL/6 mouse models to evaluate the body weight,liver histology,plasma LDL-C,liver TG and liver total lipid content,and further investigate plasma leptin level and liver ACCβ m RNA transcription and protein expression of lipid metabolism related.The main findings are as follow:1.Compared with tea fresh leaves,All kinds of tea catechins content showed significant difference(P<0.001).The content of catechins in white tea,oolong tea and black tea decreased by 34%,36%,and 90%(P<0.001),respectively.2.Compared with the high fat diet group,the weight of each tea intervention group showed different degrees of decline.Fresh leaves group,Green Tea group,white tea group,yellow tea group group,black tea group weight decreased by 21.5%,21%,34%,18.6%,16.7%(P<0.001),oolong tea group weight decreased by 13.8%(P<0.01),and there was no significant difference among all tea intervention groups.The tea group significantly decreased the liver weight(P<0.001),fresh leaves group,green tea group,white tea group,yellow tea group,oolong tea group and black tea group liver weight decreased 43.8%,43.3%,48.1%,41.4%,39.5%,respectively,and there was no significant difference among all tea intervention groups.The histological and pathological observation showed that all intervention tea groups were effective in reducing fat accumulation in tissues.3.The plasma LDL-C levels in all tea intervention groups were significantly lower than the high fat group,and green tea group,white tea group and black tea group decreased by 45%,38.4%,42.8%(P<0.001)respectively,yellow tea group decreased 24.7%(P<0.01),there were no significant difference among all tea groups.The content of liver fat was significantly decreased in the fresh leaves group and the yellow tea group by 59.7% and56.6%(P<0.001),respectively.The liver fat content of green tea,white tea and black tea were decreased by 53.2%,56.3%,and(P<0.01)respectively.Compared with the high fat group,the liver fat content in the fresh leaves group and the yellow tea group decreased by59.7% and 56.6%(P<0.001)respectively.Green tea,white tea and black tea group were reduced by 53.2%,56.3%,(P<0.01),oolong tea group decreased by 41.8%(P<0.05).Meanwhile,all kinds of tea intervention group were significantly decreased liver TG levels(P<0.001),decreased by 72%,76.1%,68.5%,50.6,60.6%,48%,and 68.4%,respectively.4.Compared with the high fat group,all kinds of tea intervention group were significantly decreased plasma levels of leptin(P<0.01),the fresh leaves group,green tea group,white tea group,yellow tea group,black tea group plasma leptin levels were decreased by 72.5%,85.2%,91%,82.5%(P<0.001),respectively.Oolong tea group decreased by 50%(P<0.01).All tea intervention groups liver m RNA on the transcriptional level of ACC beta were significantly lower,green tea group,oolong tea group and black tea group were down 46.1%,38.2%,47.1%(P<0.01),respectively.fresh leaves group,white tea group,yellow tea group were down 44.1%,34.3%,40.2%(P<0.05),and each kind of tea intervention group had no significant difference.These results suggest that the processing technology of five tea types formed typical chemical characteristics,At the same time,the high fat diet induced obesity mouse model showed significant lipid-lowering activity,and there was no statistical difference between the tea types.In addition,we further clarified that the lipid lowering activity of various tea types is depend on the leptin,ACC beta of lipid metabolism.