Researches On Chemomics And Functional Mechanism Of Hypolipidemic And Anti-obesity Of Dark Tea

Dark tea, one of the six major types of Chinese tea, which has been a necessarybeverage for the ethnic groups living in border regions of northern and western China.Despite the rough raw material and less water soluble components in dark tea, thesignificantly anti-obesity and hypolipidemic effect of dark tea were observed by ourprevious studies and the long-time consumption. For exploring the chenomicscharacteristic,22common chemical components in65Chinese dark teas wereanalyzed and the differences in the composition of different dark tea was explored byPCA method. UPLC-Q/TOF was used for comprehensive analysis of the water extractfrom six types of dark tea. The difference of chemical fingerprint chromatography andcharacteristic component were also compared in different types of dark tea. ThroughMRM analysis,19known bio-active ingredient showed a significantly different levelin different dark teas. The full chemical profile showed significantly difference indifferentdark teas.92phytochemical compounds were identified in dark teas, whichinclude catechins and its derivatives, phenolic acid and its derivatives, flavones andflavoneglycoside, organic acids and procyanidins, etc.Fuzhuan brick tea and Liubao teawere selected for evaluating the anti-obesityand hypolipidemic effect of dark tea. Through establishing the model of obesity andhyperlipidemia rats,3T3-L1preadipocyte cell and HepG2cell model, physiologicaland biochemical analysis, cell proliferation, differentiation and metabolism analysis,gene expression and proteomic analysis, the results showed that dark tea couldsignificantly lose weight and reduce blood fat in a dose-depended manner. Animalexperiment showed that dark tea significantly suppressed the increase of body weightand accumulation of adipose tissue, and reduced the level of serum TG, TC andLDL-C in obese rats fed a high-fat diet. Moreover, dark tea attenuated the geneexpression of FAS, SREBP-1c and C/EBP-α, which is related to lipogenic metabolismand adipose differentiation. In contrast, the gene expressions of enzymes involved inenergy expenditure and lipodieresis including hepatic PPAR-α, CPT-1a andLDLRgene expression were increased by dark tea treatment. Cell experiment showedthat dark tea inhibited proliferation and differentiation3T3-Ll, and also lowered TGand TC contents in HepG2in a dose-depended manner. Dark tea also regulated thegenes expression that related to lipid metabolism. Quantitative proteomics analysis using2-DE-LC-MS/MS technology also showed that dark teasignificantlydown-regulated the protein expression of ACACB, FAS and GPD195,which relatedfatty acid synthesis and lipogenesis. And the protein expression of CPT1, CPT2,ECHS1and HADH that related to β-oxidation were up-regulated by dark teatreatment, which lead to inhibition of fatty acid synthesis and enhance the β-oxidationof fatty acid. Additionally, some putative drug targets were also revealed that couldattenuate deleterious effects of metabolic diseases on liver such as COX2, ACACB,FAS, ECHS1.In conclusion, this research preliminarily revealed the chemicalcharacteristics of dark tea, explored the effect and mechanisms of dark tea onregulating hyperlipidemia and reducing obesity on physiological and biochemical,cytology, genomic and proteomic levels.