A Metabonomic Study For The Quality Assessment Of Teas And The Detection Of Metabolic Effects Of Puer Tea Ingestion

Puer tea is a unique Chinese post-fermented tea manufactured from Camellia sinensis (Linn.) var. assamica (Masters) Kitamura in Yunnan Province of China. Owing to its special flavor properties and potential healthy benefits such as lowering the atherogenic index, increasing HDL-total cholesterol ratio and antiobese effect, Puer tea is consumed in large amount in Asia, especially in southwestern China. Very complex changes take place to form special quality and flavor characteristics in Puer tea due to the coordination of microbial metabolic action and natural oxidation. However, most of the studies on Puer tea have focused on the characterization and assessment of the biological activity of individual extractable components and their effect on a certain animal pharmacological model. Little has been studied on the response of human biological systems to the intake of Puer tea.Metabonomics or metabolomics is the quantitative measurement of the multiparametric time-related metabolic responses of a complex (multicellular) system to a pathophysiological intervention or genetic modification. Thus metabonomics seeks to assess homeostatic and pathological responses to interventions on the global system level. Metabolome is the result of whole expression of proteome, transcriptome, genome which reflect the biochemical status of tissues directly. Urine sampling is non-invasive and commonly used for in vivo metabolic profiling. It is very important for the illustration of the complicated life systems because of the sensitive response of the changes of the philological and pathological status of the life. The main characteristics of metabonomics are the high-throughput experiment and calculation. In this disseration, we tried to use the metabonomic technique to generate the global metabolic response to the Puer tea ingestion in healthy population.A rapid analytical method for quality assessment of defferent kinds of tea by ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS) was described. Qualitative methodological considerations, including the linear range, precision, reproducibility and sensitivity were provided also. In summary, this tudy demonstrate that metabonomic analysis using UPLC/Q-TOF-MS coupled with multivariate statics provides some useful information in the study of Puer tea.A metabonomic strategy, utilizing UPLC/Q-TOF-MS in conjunction with multivariate statistics, has been applied to the study of human biological responses to Puer tea ingestion. Thirty healthy male (n=15) and female (n=15) volunteers were enrolled in this study. Daily urine samples were collected from volunteers during a 6-week period incorporating a 2-week baseline period, 2 weeks of daily Puer tea ingestion, and a 2-week'post-dosing'phase. Although some intersubject variation in metabolite profiles was observed, clear differentiation between the samples obtained before and after Puer tea ingestion was achieved, on the basis of increased urinary excretion of inositol, myristic acid, 5-hydroxy-tryptophan, 4-methoxyphenylacetic acid and decreased creatinine, 3-chlorotyrosine, and tyramine concentration. The results showed the metabolic patterns of objects during the consumption of Puer tea deviates from the baseline period, whereas the metabolic patterns of objects after Puer tea intake leading to a stable pattern approaching the predose state. This study highlights the potential for metabonomic technology in the assessment of nutritional interventions, despite the high degree of variation from genetic and environmental sources.