Pu-erh Tea Extract Research Articles

Development of a Method for the Simultaneous Analysis of Gallic Acid and Caffeine in Health Functional Foods Containing Pu-erh Tea Extract

Development of a Method for the Simultaneous Analysis of Gallic Acid and Caffeine in Health Functional Foods Containing Pu-erh Tea Extract

Bioactive components and mechanisms of Pu-erh tea in improving levodopa metabolism in rats through COMT inhibition.

Catechol-O-methyltransferase (COMT) plays a central role in the metabolic inactivation of endogenous neurotransmitters and xenobiotic drugs and hormones having catecholic structures. Its inhibitors are used in clinical practice to treat Parkinson's disease. In this study, a fluorescence-based visualization inhibitor screening method was developed to assess the inhibition activity on COMT both in vitro and in living cells. Following the screening of 94 natural products, Pu-erh tea extract exhibited the most potent inhibitory effect on COMT with an IC50 value of 0.34 μg mL-1. In vivo experiments revealed that Pu-erh tea extract substantially hindered COMT-mediated levodopa metabolism in rats, resulting in a significant increase in levodopa levels and a notable decrease in 3-O-methyldopa in plasma. Subsequently, the chemical components of Pu-erh tea were analyzed using UHPLC-Q-Exactive Orbitrap HRMS, identifying 24 major components. Among them, epigallocatechin gallate, gallocatechin gallate, epicatechin gallate, and catechin gallate exhibited potent inhibition of COMT activity with IC50 values from 93.7 nM to 125.8 nM and were the main bioactive constituents in Pu-erh tea responsible for its COMT inhibition effect. Inhibition kinetics analyses and docking simulations revealed that these compounds competitively inhibit COMT-mediated O-methylation at the catechol site. Overall, this study not only explained how Pu-erh tea catechins inhibit COMT, suggesting Pu-erh tea as a potential dietary intervention for Parkinson's disease, but also introduced a new strategy for discovering COMT inhibitors more effectively.

Pu-erh tea intake enhances the anti-obesity effect of intermittent fasting via modulating follicle-stimulating hormone and gut dysbacteriosis in female high-fat-diet mice

Intermittent fasting (IF) could not work well in females indicating that additional interventions might be necessary to improve outcomes. We here investigated whether Pu-erh tea extract (PTE) intake could enhance anti-obesity effect of IF in female mice and explored the underlying mechanisms. The combination of PTE and IF treated obesity by reducing lipogenesis and enhancing adipose thermogenesis. This combination might decrease follicle-stimulating hormone (FSH) to reduce FSH-mediated UCP1 inhibition by AMPK/PGC1α/UCP1 pathways, finally promoting adipose thermogenesis. Based on this, we speculated increase of FSH might be a key reason for poor anti-obesity effect in female mice under IF. Besides, this combination modulated the composition of gut microbes (restored Firmicutes/Bacteroidetes and improved Akkermansia abundance) by protecting the intestinal barrier, and further promoted the production of SCFAs especially butyrate which might finally induce thermogenesis in adipose. Our results suggested this combination could be an effective strategy to combating obesity for females.

Formation mechanism and solution of Pu-erh tea cream based on non-targeted metabonomics

Revealing the relationship between metabolites in tea extract and cream production is challenging. This study aims to investigate the production of tea cream in the shelf life of Pu-erh tea and Oolong tea. Compared with Oolong tea, the production of Pu-erh tea cream is higher after deep fermentation. Metabonomics analysis results indicate that the compound diversity and composition structure of Pu-erh tea and Oolong tea were different, and the complexity of the compound network in Pu-erh tea extract was higher than that in Oolong tea. After screening, we identified six compounds that may be related to the formation of tea cream, including caffeine. After verification, we found that the production rate of Pu-erh tea cream decreased significantly after the caffeine content in the tea was removed by supercritical carbon dioxide extraction technology. Therefore, this study suggests that the six core compounds in the extract of Pu-erh tea are the key factors that affect the tea cream and that the production of tea cream during the shelf life of the extract can be prevented by directional removal of these core compounds. This study provides a theoretical basis for promoting the industrialization of Pu-erh tea and solving the production of tea cream.

Anti-Oxidative Effect of Pu-erh Tea in Animals Trails: A Systematic Review and Meta-Analysis.

This study adopted systematic literature review and meta-analysis methodology to explored anti-oxidative effect of pu-erh tea. Study authors have systemically searched seven databases up until 21 February 2020. In performing the literature search on the above-mentioned databases, the authors used keywords of pu-erh AND (superoxide dismutase OR glutathione peroxidase OR malondialdehyde). Results derived from meta-analyses showed statistically significant effects of pu-erh tea on reducing serum MDA levels (SMD, −4.19; 95% CI, −5.22 to −3.15; p < 0.001; I2 = 93.67%); increasing serum SOD levels (SMD, 2.41; 95% CI, 1.61 to 3.20; p < 0.001; I2 = 91.36%); and increasing serum GSH-Px levels (SMD, 4.23; 95% CI, 3.10 to 5.36; p < 0.001; I2 = 93.69%). Results from systematic review and meta-analyses validated that various ingredients found in pu-erh tea extracts had anti-oxidation effects, a long-held conventional wisdom with limited supporting evidence.

Effect of Pu-erh tea on acetaminophen-induced hepatotoxicity assessed by physiological, metabolomic, and transcriptomic analyses

• PTE pretreatment ameliorated oxidative stress, inflammatory response, and apoptosis of mice caused by excess APAP. • PTE pretreatment and APAP overdose altered the metabolic profile and gene expression of liver tissues. • PTE induced tyrosine and caffeine metabolism, and alleviated hepatotoxicity induced by excess APAP. • Six DEMs and 10 DEGs were biomarkers and key genes for liver protection in high dose APAP exposure. Acetaminophen (APAP) is a painkiller that can cause hepatotoxicity if taken in excess. We investigated the effect of pu-erh tea extract (PTE) on hepatotoxicity induced by excess APAP using physiological, metabolomic, and transcriptomic analyses. PTE decreased levels of oxidative stress, inflammatory response, and apoptosis markers induced by excess APAP. And 156 metabolites and 703 genes were identified as differentially expressed metabolites and differentially expressed genes, respectively. KEGG enrichment analysis revealed that PTE and overdose of APAP altered tyrosine, caffeine, and amino acid-related metabolism. Six differentially expressed metabolites associated with these pathways have hepatoprotective effects and were upregulated by PTE pretreatment. The expression levels of 10 vital differentially expressed genes regulating these metabolites were verified by qRT-PCR. The findings confirm the beneficial role of PTE pretreatment in alleviating the hepatotoxicity caused by overdose of APAP, indicating that PTE can be used as an effective dietary supplement for the development of functional foods.

Pu-erh tea extraction alleviates intestinal inflammation in mice with flora disorder by regulating gut microbiota.

Pu‐erh tea is very popular in Southwestern China and South Asian countries and is now becoming increasingly popular in Europe due to its well‐documented beneficial effects on human health. Pu‐erh tea aqueous extracts can maintain intestinal homeostasis. However, the mechanism of its beneficial effects on intestinal flora disorder is not clear. In this study, we focused on the effects of ripe Pu‐erh tea aqueous extracts on the intestinal microbiota in an intestinal flora disorder mouse model. Physiological indexes and the tissue section staining results showed that feeding Pu‐erh tea extract could help mice regain weight and alleviate intestinal inflammation. Further assessment of the intestinal microflora found that Pu‐erh tea extract could promote the growth of intestinal probiotics and inhibit pathogenic bacteria, thereby achieving a treatment effect for enteritis. This study provides new evidence for the therapeutic effect of Pu‐erh tea.

Pu-erh tea ameliorates obesity and modulates gut microbiota in high fat diet fed mice

Obesity is regarded to be associated with fat accumulation, chronic inflammation, and gut microbiota dysbiosis. Raw and ripened pu-erh tea extract (PETe) have the effect of reducing body weight gain and fat accumulation, which are associated with gut microbiota. However, little is known about the difference of raw and ripened PETe on the regulation of gut microbiota. Here, our results suggested that supplementation of raw and ripened PETe displayed similar anti-obesogenic effect in high fat diet (HFD)-induced obesity mice, by attenuating the body weight gain, fat accumulation, oxidative injury, and low-grade inflammation, improving the glucose tolerance, alleviating the metabolic endotoxemia, and regulating the mRNA and protein expression levels of the lipid metabolism-related genes. 16S rRNA sequencing of fecal samples indicated that raw and ripened PETe intervention displayed different regulatory effect on the HFD-induced gut microbiota dysbiosis at different taxonomic levels. The microbial diversity, the relative abundance of Firmicutes and Bacteroidetes as well as F/B ratio were reversed more closer to normal by ripened PETe. Phylotypes of Bacteroidaceae, Ruminococcaceae, Lachnospiraceae, Muribaculaceae, and Rikenellaceae which are negatively correlated with obesity were enhanced notably by the intervention of ripened PETe, while Erysipelotrichaceae and Lactobacillaceae which have positive correlation with obesity were decreased dramatically. In addition, the treatment of ripened PETe had better effect on the increase of benefical Bacteroides, Alistipes, and Akkemansia and decrease of obesity associated Faecalibaculum and Erysipelatoclostridium (p < 0.05). These findings suggested that pu-erh tea especially ripened pu-erh tea could serve as a great candidate for alleviation of obesity in association with the modulation of gut microbiota.

Ripened Pu-erh Tea Extract Promotes Gut Microbiota Resilience against Dextran Sulfate Sodium Induced Colitis.

Ripened Pu-erh tea (RPT) has been shown to be an effective natural ingredient to defend against experimentally induced colitis. We hypothesized that RPT would alleviate dextran sulfate sodium (DSS) induced colitis via modulating intestinal microbiota. The effect of RPT on mice gut microbiota was evaluated using 16S rRNA gene amplicon sequencing, broad-spectrum antibiotic (ABX) treatment, and fecal microbiota transplantation (FMT). Pretreatment with RPT enhanced intestinal barrier function, reduced colonic and serum proinflammatory cytokine and macrophage infiltration, and preserved the resilience of gut microbiota in mice during a DSS challenge. Administration of either RPT-regulated or healthy control-derived gut microbiota showed similar protection against colitis, and such protection could not be recapitulated with fecal microbiota from ABX-treated mice, suggesting a key role of protective consortium in the disease protection. Mechanistically, cecal contents of short-chain fatty acids (SCFAs) and colonic peroxisome proliferator activated receptor-γ (PPAR-γ) expression in colitis mice increased significantly by RPT intervention. Collectively, RPT treatment improved DSS-induced colitis by partially reversing the dysbiosis state of gut microbiota, which might be associated with an increase in SCFA level and PPAR-γ expression.

Study on the mechanism of the Pu-erh tea (Camellia sinensis var. assamica) extract inhibiting contraction of isolated mouse duodenum

The aims of this study were to investigate the effects of three different concentrations of the Pu-erh tea extract (PTE) on the contractile activity of the isolated mouse duodenum and explore their mechanism. The contraction amplitude and frequency of the isolated mouse duodenum were inhibited by all three concentrations of PTE. The high-concentration PTE significantly (P &lt; 0.01) inhibited the promotion effects of acetylcholine chloride or BayK8644 on the amplitude and frequency of intestinal contraction, which were comparable to those of atropine sulphate and verapamil hydrochloride, respectively. The results of UV-Vis and ELISA showed that the content of methionine-enkephalin (Met-ENK) in the PTE-treated groups was decreased to varying degrees; contrarily, the activities of tyrosine hydroxylase (TH), total nitric oxide synthase, and the content of nitric oxide were increased to different degrees. The results suggest that PTE can inhibit the contraction of the isolated mouse duodenum, and the mechanism of action is that PTE can not only inhibit the signal transduction pathways of AC-cAMP-PKA and PLC-IP3-Ca2+, but also the Ca2+ signal systems mediated by G protein-coupled M receptors through the myenteric plexus. By reducing the release of Met-ENK from the motor neurons of the myenteric plexus, the GTP-cAMP-PKK signalling pathway and the Ca2+ signalling system mediated by G protein-coupled delta receptors were inhibited. By increasing the TH activity of the motor neurons in the myenteric plexus, the norepinephrine content was increased, thereby the AC-cAMP-PKA signal transduction pathway mediated by G protein-coupled β receptors was activated. This study increases knowledge regarding the medicinal value of the Pu-erh tea.

Characterization of Furcellaran-Whey Protein Isolate Films with Green Tea or Pu-erh Extracts and Their Application as Packaging of an Acid-Curd Cheese

In recent years, there has been a serious need to develop and test new biodegradable packaging. Therefore, furcellaran (FUR) and whey protein isolate (WPI) films containing pu-erh (PE) or green tea (GT) extracts were prepared in this study. The effect of the extracts on the structure, rheological and mechanical properties, and antioxidant and antimicrobial activity of FUR/WPI films was tested. The films were applied as packaging of an acid-curd cheese (quark). Water content, pH, water activity, and microbiological and organoleptic quality of cheese were examined. The storage loss modulus increased with the PE addition as well as tensile strength (by 1.37 MPa) and antioxidant activity (by 42.5 percentage points). The GT addition caused no changes in rheological properties but did affect tensile strength (an increase by 1.33 MPa), elongation at break values (a decrease by 7.08 percentage points), and antioxidant activity (an increase by 39.33 percentage points). The FUR/WPI with GT revealed bacteriostatic effect against Staphylococcus aureus. The number of Lactococcus and total bacteria count decreased in almost all cheeses during storage (approximately by 1–2 log cfu g−1), except FUR/WPI + PE. The yeast count increased during storage in all samples (approximately by 4.3–5.5 log cfu g−1), regardless of packaging used. Most of the examined films had a negative influence on organoleptic quality of cheese, especially after storage. Therefore, they were found not to be appropriate as packaging of an acid-curd cheese. However, this research did enable the obtaining of a new edible film with good mechanical properties—the FUR/WPI + PE film.

Tea extracts modulate oral biofilm development by altering bacterial hydrophobicity and aggregation

ObjectivesThis study aims to investigate the effects of tea extracts on biofilm formation by oral streptococci and the potential mechanisms behind the effects. DesignWe examined the effects of five types of tea extracts (green, oolong, black, pu-erh and chrysanthemum tea) on cell surface hydrophobicity and auto-aggregation of three different streptococcal species (Streptococcus mutans, Streptococcus salivarius and Streptococcus mitis) and evaluated their biofilm formation on four disparate hard surfaces (glass, stainless steel, hydroxyapatite and titanium). The correlation between biofilm formation and the cellular properties were investigated in order to study the mechanisms by which the tea extracts affect biofilm formation. ResultsResults show that the tea extracts reduced cell surface hydrophobicity (by up to 57.9 %) and, in some cases, altered cellular auto-aggregation (by up to 12 %) and biofilm formation (by up to 2.61 log CFU cm−2). Specifically, oolong tea extract was found to enhance biofilm formation by increasing cellular auto-aggregation and pu-erh tea extract retarded biofilm formation by increasing auto-aggregation. Biofilm formation correlated well to cell surface hydrophobicity and auto-aggregation in combination, but not to either one alone as determined by multiple linear regression analysis. ConclusionsTea extracts have the ability to modulate streptococcal biofilm formation by altering cell surface hydrophobicity and cellular aggregation.

A simple and portable method for β-Glucosidase activity assay and its inhibitor screening based on a personal glucose meter

In this study, a simple and portable enzyme activity assay and inhibitor screening method was developed based on β-Glucosidase-mediated cascade reaction in a personal glucose meter (PGM). The inhibition of castanospermine (β-Glucosidase inhibitor) on β-Glucosidase leads to reducing the yields of glucose and saligenin produced by the catalysis hydrolysis of D (−)-Salicin. The ferricyanide (K3 [Fe(CN)6]) can be reduced by the products of glucose and saligenin to form ferrocyanide ([K4[Fe(CN)6]) in the glucose strips, and thereby get the electron to generate PGM detectable signals. This strategy can realize the direct determination of glucose and saligenin using PGM as simple as measuring the glucose in blood. Under the optimum experimental conditions, quantitative detection of β-Glucosidase in crude almond sample was achieved within the ranges of 1.0–9.0 U/mL with the limit of detection of 0.45 U/mL. The recoveries of β-Glucosidase spiked with two different concentrations (3.0 and 6.0 U/mL) in the crude bitter almond extracts were determined as 96.2% and 84.3%, respectively. Furthermore, gallic acid, protocatechualdehyde, cryptochlorogenic acid, epigallocatechin, epicatechin and vanillic acid exhibited good inhibitory effect (all higher than 40%) on β-Glucosidase. In addition, tea polyphenol extracts of raw Pu-erh and Fuding white tea had good inhibition potency and the % of inhibition were (29.0 ± 3.5)% and (21.1 ± 2.2)% on β-Glucosidase, respectively. Finally, molecular docking study indicated that hydrogen bonding plays an important role in the interaction between the compounds and β-Glucosidase. The enzyme activity assay and inhibitor screening method developed in present study using PGM based on β-Glucosidase-mediated cascade reaction would be of value for expanding the application of PGM in non-glucose target analysis.

Pu-erh Tea Extract Treatment Could Be an Efficient Way to Enhance the Yield and Nutritional Value of Soybean Sprout.

Soybean sprouts are one of the most inexpensive and nutritious food items that can be easily grown year-round. Several studies have been conducted to increase their yield and nutritional values. This study was carried out to examine the effects of Pu-erh tea extracts on the production and nutrients content of soybean sprouts. Soybean seeds were soaked in 1%, 2%, or 3% (w/v) tea extracts, or tap water, before keeping for sprout cultivation; the sprout samples were named PE-1, PE-2, PE-3, and the control, respectively. The sprout yields were increased by up to 17% in PE-2 and PE-3 than in the control. The vitamin C, total free amino acid, total mineral, total isoflavone, total polyphenol, and flavonoid contents as well as the antioxidant potentials of the tea extract-treated sprouts were higher than those of the control. The results indicated that pre-soaking soybean seeds in 2% Pu-erh tea extracts could offer an easy, inexpensive, and efficient way to improve the yield and nutritional value of soybean sprouts.

Optimizing the extraction of bioactive compounds from pu-erh tea (Camellia sinensis var. assamica) and evaluation of antioxidant, cytotoxic, antimicrobial, antihemolytic, and inhibition of α-amylase and α-glucosidase activities

The aims of this study were to quantify and optimize the extraction of total phenolic content (TPC), total flavonoids (TF) and antioxidant activity (AA) of aqueous pu-erh (Camellia sinensis var. assamica) extracts, as well as to compare the optimized pu-erh tea extract (OPT) with toasted mate (Ilex paraguariensis), black and green (Camellia sinensis) teas. The optimization process increased the TPC and the ferric reducing antioxidant power (FRAP). The results showed that the green tea extract presented the highest values for TPC and antioxidant capacity. The pasteurized OPT showed lower TPC and TF, and higher FRAP, DPPH and Cu2+ chelating ability compared to the non-pasteurized OPT. The lyophilized OPT showed inhibition of lipid peroxidation in Wistar rat brain homogenate and displayed antibiofilm activity against Enterococcus faecalis ATCC 25212 and 19433, and Staphylococcus aureus ATCC 25923. Additionally, lyophilized OPT presented cytotoxic and antiproliferative effects against tumor cell lines (Caco-2, A549 and HepG2), inhibited the production of reactive oxygen species in A549 and IMR90 cells, and presented antihemolytic activity in human erythrocytes. The lyophilized OPT inhibited α-glucosidase (IC50 = 47.0 µg/mL) and α-amylase at 30.0 mg/mL. The main compounds detected in OPT were gallic acid, caffeine and theobromine.

Inhibitory Effect of the Theabrownin and Tea Polysaccharide Extracts of Dark Tea on Lipase

In order to investigate the effect of theabrownin and tea polysaccharide of dark tea on reducing fat and weight, theabrownin and tea polysaccharide extracted from dark tea of the same level in different regions were studied in this experiment and p-nitro phenol method and enzyme kinetics method was used to analyze the inhibition effects of theabrownin and tea polysaccharide on lipase, and the inhibition mechanism of tea theabrownin and tea polysaccharide on lipase was explored. The results showed that theabrownin and tea polysaccharide of dark tea extracts had a good inhibitory effect on lipase. Among them, theabrownin extracts of Pu-erh tea had the best inhibitory effect, and the IC50 of the semi-inhibitory concentration was the smallest at 24.21mg .mL−1, which was significantly less than semi-inhibitory concentrations of theabrownin extracts from dark tea in the other three regions( P<0.01). The inhibitory effect of polysaccharide extract of Liubao tea was the best, and the IC50 of the semi-inhibitory concentration was the smallest, which was 58.57mg · mL−1. It is not significantly different from the semi-inhibitory concentration of the tea polysaccharide of Pu-erh and Kang brick, but it was significantly greater than the semi-inhibitory concentration of Fu-brick tea polysaccharide (P <0.01).The results of kinetic studies showed that the catalyst type of tea theabrownin extract of all teas was a mixed type, which contained competitive and non-competitive type in a reversible inhibition type. The catalyst type of tea polysaccharide extract of Pu-erh tea, Liubao and Tibetan tea tea were mixed types, which contained competitive and noncompetitive type in a reversible inhibition type. The catalyst type of polysaccharide extract of Fu-brick tea was a reversible inhibition type and its inhibition type was competitive inhibition. In conclusion, the theabrownin extract of Pu-erh tea and tea polysaccharide extract of Liubao tea had the best inhibitory effect on the lipase.

Gut Microbiome and Metabolome Response of Pu-erh Tea on Metabolism Disorder Induced by Chronic Alcohol Consumption

This study investigated the protective effects of pu-erh tea extract (PTE) on alcohol-induced microbiomic and metabolomic disorders. In chronic alcohol-exposed mice, PTE ameliorated chronic alcoholic consumption-induced oxidative stress, inflammation, lipid accumulation, and liver and colon damage through modulating microbiomic and metabolomic responses. PTE restored the alcohol-induced fecal microbiota dysbiosis by elevating the relative abundance of potentially beneficial bacteria, for example, Bifidobacterium and Allobaculum, and decreasing the relative abundance of potentially harmful bacteria, for example, Helicobacter and Bacteroides. The alcohol-induced metabolomic disorder was modulated by PTE, which was characterized by regulations of lipid metabolism (sphingolipid, glycerophospholipid, and linoleic acid metabolism), amino acid metabolism (phenylalanine and tryptophan metabolism), and purine metabolism. Besides, the bacterial metabolites of phytochemicals in PTE might contribute to the protective effects of PTE. Overall, PTE could be a functional beverage to treat chronic alcohol consumption-induced microbiomic and metabolomic disorders.

Effect of Powdered Beverages Containing Pu-erh Tea Extract on Postprandial Blood Glucose Levels

Objective: The current study aimed to examine the effect of a single ingestion of a beveragecontaining Pu-erh tea extract (Pu-erh tea polyphenol 32.48mg, eq. gallic acid) on postprandialblood glucose levels through a comparison using a crossover test.Method: A total of 20 participants, of which 10 were men and 10 were women, aged between 29 and 64 years were instructed to ingest beverages containing Pu-erh tea extract or placebo beverages at the same time as load food (in addition to cooked rice). Their blood glucose levels were measured before and 30, 60, 90, and 120 min after ingestion.Results: In phases I and II of the trial, three participants who had large differences in the quantity of the ingested food on the day before the trial were removed from the study. Finally, the analysis was conducted on 17 participants. Result showed that the group who ingested the beverage containing Pu-erh tea extract had significantly lower blood glucose levels than the group who consumed the placebo beverage 60, 90, and 120 min after ingestion. In terms of the amount of variation before ingestion, the group who ingested beverages with Pu-erh tea extracts had significantly lower blood glucose levels than the group who consumed the placebo beverage 60, 90, and 120 min after ingestion. In terms of area under the curve (AUC) and increase in the area under the curve (IAUC) for blood glucose levels with some variations, the time it took for the participants to consume the trial beverage compared with the placebo beverage was significantl lower.Conclusion: Beverages containing Pu-erh tea extract were found to be effective in suppressingthe increase in postprandial blood glucose levels after being loaded with cooked rice.Keywords: Pu-erh tea, postprandial blood glucose, cooked rice, type 2 diabetes

Ripened Pu-erh Tea Extract Protects Mice from Obesity by Modulating Gut Microbiota Composition

Ripened Pu-erh tea extract contributes to reducing weight gain and fat accumulation; however, the role of gut microbiota on the antiobesity effect of ripened Pu-erh tea extract in obese mice remains unclear. This study aims to explore the role of alterations in gut microbes mediated by ripened Pu-erh tea extract in obese mice through 16S rRNA sequencing and a fecal transplant trial. Our results suggested that drinking water containing ripened Pu-erh tea extract could decrease weight gain, fat accumulation, adipose inflammation, the Firmicutes-to-Bacteroidetes ratio, and metabolic endotoxemia while, in the meantime, improving the intestinal barrier integrity in obese mice. Moreover, the fecal transplant trial indicated that feces from the donor mice treated with ripened Pu-erh tea extract could significantly modulate weight and metabolic syndrome in the recipient mice. Thus, our results indicated that gut microbiota can mediate the function of ripened Pu-erh tea extract against obesity; additionally, ripened Pu-erh tea extract can potentially prevent individuals from being obese through rebalancing the gut microbiota.

Ripe and Raw Pu-Erh Tea: LC-MS Profiling, Antioxidant Capacity and Enzyme Inhibition Activities of Aqueous and Hydro-Alcoholic Extracts.

Herein, we reported a detailed profiling of soluble components of two fermented varieties of Chinese green tea, namely raw and ripe pu-erh. The identification and quantification of the main components was carried out by means of mass spectrometry and UV spectroscopy, after chromatographic separation. The antioxidant capacity towards different radical species, the anti-microbial and the enzyme inhibition activities of the extracts were then correlated to their main constituents. Despite a superimposable qualitative composition, a similar caffeine content, and similar enzyme inhibition and antimicrobial activities, raw pu-erh tea extract had a better antioxidant capacity owing to its higher polyphenol content. However, the activity of raw pu-erh tea seems not to justify its higher production costs and ripe variety appears to be a valid and low-cost alternative for the preparation of products with antioxidant or antimicrobial properties.