Fermented Pu-erh Tea Research Articles

Multi-omics analysis of the metabolism of phenolic compounds in tea leaves by Aspergillus luchuensis during fermentation of pu-erh tea

Aspergillus fungi are extensively used in traditional food fermentation, so their functions, mechanisms, and safety risks are worth exploring. In this study, a dominant fungal strain (P1) was isolated from a fermented pu-erh tea and identified as A. luchuensis by phylogenetic analysis of fungal internally-transcribed spacer sequencing, partial β-tubulin and calmodulin genes. A pure-strain fermentation of tea leaves was developed, and tea compounds were analyzed by widely-targeted metabolomics, using high-performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC-MS). The mycotoxins, aflatoxin (B1, B2, M1 and M2), fumonisin B1 and B2, ochratoxin A, citrinin, were not detected in fermented tea leaves using methods in the National Standard of the Peoples’ Republic of China. The genome of 36.60 Mb with 11,836 protein-coding genes was sequenced by PacBio sequencing and annotated. Expression of fungal genes during fermentation was analyzed by Illumina HiSeq 2500; genes encoding enzymes including glycoside hydrolases, phenolic acid esterases, laccases, tyrosinases, dehydrogenases, peroxidases, dioxygenases, monooxygenases, decarboxylases and O-methyltransferases were identified. These enzymes catalyze hydrolysis, oxidation, ring cleavage, hydroxylation, decarboxylation and O-methylation of phenolic compounds , significantly (p < 0.05) changing the phenolic compound composition. While, phenolic compounds were degraded through degradation of aromatic compounds pathways and xenobiotics biodegradation and metabolism pathways. These findings advance knowledge of the functions and mechanisms of action of Aspergillus in traditional food fermentation.

Interrelation analysis between phenolic compounds and in vitro antioxidant activities in Pu-erh tea

Pu-erh tea is a Chinese dark tea produced by sun-dried green tea-leaves. In this study, 17 phenolic compounds and 3 purine alkaloids in 36 Pu-erh teas were determined by high-performance liquid chromatography. Additionally, the in vitro antioxidant activities were evaluated by 5 various assays, respectively. PCA, HCA and OPLS-DA (R2X = 0.639, R2Y = 0.945 and Q2 = 0.940, respectively) could divide into fermented Pu-erh tea (FPT) and non-fermented Pu-erh tea (NFPT) groups absolutely. Compared with NFPT, solid-state fermentation caused the extremely significant (p < 0.001) decreases of 8 catechins, 3 other flavonoids (i.e. taxifolin, rutin and luteolin), gallic acid (GA), hydrolyzed tannin and theophylline, and enhanced ellagic acid, kaempferol and quercetin contents significantly (p < 0.05, <0.01 or <0.001) in FPT. Bivariate correlation analysis confirmed that 8 catechins, 3 flavonoids, theophylline and GA promoted the antioxidant activities of Pu-erh teas, while queretin showed extremely significantly (p < 0.001) negative correlation to the results of DPPH, ABTS and HSA assays. Furthermore, multivariate linear regression equations efficiently evaluated the results of FRAP, DPPH, ABTS and HSA assays in Pu-erh tea with a R2 value over 0.95. This study elaborating the interrelation between phenolic compounds and in vitro antioxidant activities advanced the knowledge about Pu-erh tea.

Lovastatin suppresses bacterial therapy-induced neutrophil recruitment to the tumor by promoting neutrophil apoptosis

• Lovastatin clearance of neutrophil at the inflammatory site by apoptosis. • BCT-induced neutrophil recruitment within tumor abrogated by lovastatin. • Natural compounds combined with BCT is promising anti-cancer therapy. Lovastatin is a statin produced by Monascus purpureous -fermented pu-erh tea, which is used in the treatment of cardiovascular diseases and prostate cancer. Bacteria-mediated cancer immunotherapy (BCI), which is an effective antitumor strategy compared with conventional immunotherapies, targets neutrophil infiltration associated with tumor recurrence and metastasis. In mouse colon cancer models, combination treatment with lovastatin and BCI suppressed tumor progression by extending the survival of tumor-colonizing bacteria. We used zebrafish live imaging to show that lovastatin decreases the recruitment of neutrophils to the inflammatory site by inducing neutrophil apoptosis via phosphorylation of ERK and AKT. The present findings suggest that the combination of BCI with lovastatin or fermented pu-erh tea is an effective approach compared with conventional cancer immunotherapy.

Making a cup of carbon dots for ratiometric and colorimetric fluorescent detection of Cu2+ ions

Fluorescence carbon dots (CDs) are firstly obtained from microbial fermented Pu-erh tea by a simple brewing method without high temperature treatment as reported in literature. The obtained CDs contain abundant surface functional groups and exhibit a good ability to detect Fe and Cu ions. Moreover, a new sensing universal platform that can simultaneously apply fluorescent and colorimetric dual-readout for Cu2+ detection is constructed using the obtained CDs and o-phenylenediamine (OPD). Not only does this sensing platform exhibit much higher selectivity and sensitivity than pure CDs, but it also enhances detection scope for Cu2+. Its detection mechanism is dominated by synergistic combination of fluorescence quenching resulted from the coordination reaction of Cu2+ ions and fluorescence resonance energy transfer from CDs to the oxidation product of OPD.

158 - Evaluation of the Free Radical Scavenging Capacity of Fresh and Fermented Pu-Erh Tea

Dried tea leaves (Camellia sinensis) contain various antioxidant molecules depending on their origin and preparation method. Computational methods are used to calculate the thermodynamic properties of their phenolic compounds as well as their free radical scavenging capacity. Extracts from young Puerh tea shoots and fermented cakes originated from tea forests in China's Yunnan province were analysed. The more a weak O-H bond dissociation enthalpy (BDE) is, the greater the capacity of an O-H to give its hydrogen and act as an antioxidant. The theoretic calculations on the main phenolic compounds present (gallic acid, catechin, epicatechin, epigallocatechin (EGC), epigallocatechin gallate (EGCG), epicatechingallate (ECG), and theaflavin) demonstrate the importance of the catechol and galloyl nuclei. Moreover, theaflavin contains a trihydroxy-annulene nucleus with a ketone forming a hydrogen bonds stabilising network. Superoxides and singlet oxygens are toxic energetic radicals involved in skin ageing, effects of UV light and pollution. Comparing the BDE values and kinetic constants on superoxides gives the following ranking: EGCG>ECG ≈ EGC>catechin ≈ epicatechin. The theoretic assessment of the kinetic constants of the scavenging capacity of singlet oxygen indicates similar and very high values (107-108 M-1.s-1) for the compounds, which suggest they are effective at scavenging these radicals. Extracts from young leaves rich in particularly active catechol and galloyl fragments, are able to scavenge the main reactive oxygen species (hydroxyl, alkoxyl, peroxyl, superoxide, singlet oxygen) at a faster rate. The high concentration of theaflavin in young leaf extract increases its superoxide scavenging. Extracts from fermented tea cakes richer in catechin oligomers (average degree of polymerisation 3-4), explains the enzyme inhibition and detoxifying activities. The use of one of the two extracts or a combination enables to modulate a potential skin care action.

The Microbiome and Metabolites in Fermented Pu-erh Tea as Revealed by High-Throughput Sequencing and Quantitative Multiplex Metabolite Analysis.

Pu-erh is a tea produced in Yunnan, China by microbial fermentation of fresh Camellia sinensis leaves by two processes, the traditional raw fermentation and the faster, ripened fermentation. We characterized fungal and bacterial communities in leaves and both Pu-erhs by high-throughput, rDNA-amplicon sequencing and we characterized the profile of bioactive extrolite mycotoxins in Pu-erh teas by quantitative liquid chromatography-tandem mass spectrometry. We identified 390 fungal and 629 bacterial OTUs from leaves and both Pu-erhs. Major findings are: 1) fungal diversity drops and bacterial diversity rises due to raw or ripened fermentation, 2) fungal and bacterial community composition changes significantly between fresh leaves and both raw and ripened Pu-erh, 3) aging causes significant changes in the microbial community of raw, but not ripened, Pu-erh, and, 4) ripened and well-aged raw Pu-erh have similar microbial communities that are distinct from those of young, raw Ph-erh tea. Twenty-five toxic metabolites, mainly of fungal origin, were detected, with patulin and asperglaucide dominating and at levels supporting the Chinese custom of discarding the first preparation of Pu-erh and using the wet tea to then brew a pot for consumption.

Safety evaluation and antihyperlipidemia effect of aqueous extracts from fermented puerh tea.

Fermented puerh tea, having undergone a long period of secondary oxidization and fermentation, has become more and more popular in recent years. In the present paper, a safety evaluation of aqueous extracts from fermented puerh tea (EFPT) was performed, including an oral acute toxicity study in rats and mice, mutation tests, a mouse micronucleus test, mouse sperm abnormality test and a 30 day feeding study in rats. Meanwhile, the antihyperlipidemia effect of EFPT was investigated as well. It was found that the oral maximum tolerated dose of EFPT was more than 10.0 g per kg body weight both in rats and mice. And it had no mutagenicity as judged by negative experimental results of the mutation test. No abnormal symptoms, clinical signs or deaths have been found in rats in each group throughout the experiments. In addition, EFPT in this study showed certain effects on hyperlipidemia.

Fermented Pu-erh Tea Increases In Vitro Anticancer Activities in HT-29 Cells and Has Antiangiogenetic Effects on HUVECs

Pu-erh tea is produced in China and known to possess medicinal properties. The anticancer and antiangiogenesis effects of fermented Pu-erh tea on HT-29 colon cancer cells and human umbilical vein endothelial cells, respectively, were examined. Two kinds of unfermented and fermented Pu-erh tea (Seven-son tea cake Pu-erh tea and Xiaguan bowl tea [X]) and green tea were used. An MTT assay showed fermented Pu-erh tea X (85% inhibition) possessed more potent anticancer activities than unfermented Pu-erh tea X (67% inhibition) and green tea (53% inhibition) (P < 0.05). Moreover, fermented Pu-erh tea X increased the number of apoptotic bodies determined through DAPI staining and flow cytometric analysis. Fermented Pu-erh tea X induced apoptosis indicated by increased expression of Bax, caspase-9, and caspase-3 messenger RNA and decreased expression of Bcl-2. Fermented Pu-erh tea X also had an anti-inflammation effect, shown in decreased expression of nuclear factor-κB-p65, inducible nitric oxide synthase, COX-2 messenger RNA and increased expression of IκB-α. Further, fermented Pu-erh teas showed stronger antiangiogenesis effects than the 2 other types of tea. After fermentation, the concentrations of gallic acid, resorcylic acid, quercetin, and kaempferol in Pu-erh tea were increased. These results collectively indicated that fermented and unfermented Pu-erh teas possess stronger anticancer and antiangiogenesis effects than green tea. Furthermore, fermented Pu-erh tea showed stronger functional activities than unfermented Pu-erh tea.

普洱茶调节apoE基因敲除小鼠血脂水平的研究

为了验证普洱茶对apoE基因敲除小鼠动脉粥样硬化的作用；本研究选取了40只4周龄雄性apoE基因敲除小鼠，按照体重随机分成降脂药组、模型组、生茶组、熟茶组4组外加10只正常对照组。用普洱茶汤进行干预性试验90天后，空腹12小时，摘眼球采血，采用全自动生化仪测血清中的总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL-C)等血脂指标；试验结果显示：普洱茶(生、熟)均可显著控制小鼠体重增长(P 0.05)；普洱生茶可显著降低小鼠血清中TG、LDL-C的含量，升高HDL-C的含量(P )，可显著降低AI系数；因此可判定，普洱茶对apoE基因敲除小鼠的抗动脉粥样硬化有一定的调节作用。This study aimed to investigate the effects of Pu-erh tea on blood lipids in apoE-knockout mice. So we selected 4-week-old male apoE-gene knocked mice, and they were randomly divided into four groups: atherosclerosis group, fermenting Pu-erh Tea group, fermented Pu-erh Tea group and drug group. The all mice were used as the control. All mice were fed with normal chow diet. After 90 days, Vessels blood was collected for serum lipid, using automatic biochemical analyzed measuring serum the total clesterol (TC), triglycerides (TG), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), and other hyperlipidemia indicators. The result is that Pu-erh Health (cooked) tea cansignificantly increase control of body weight (P

Pu-erh tea can inhibit atherosclerosis by promoting macrophage apoptosis in plaque through NF-κB pathway in ApoE null mice

PurposePu-erh tea has recently become very popular in China and most southeast Asian countries. Fermented Pu-erh tea may help regulate blood lipids, prevent and treat atherosclerosis (AS). Below, we discuss...

Pu-erh tea aqueous extracts lower atherosclerotic risk factors in a rat hyperlipidemia model

Pu-erh tea is believed to possess many beneficial health effects since it is a natural source of cardioprotective lipid lowering and antioxidant compounds, although, the major constituents putatively responsible for these beneficial effects remain unknown. In this study, we examined the effects of two commonly consumed forms of Pu-erh tea, fermented and unfermented, on weight gain, serum levels of lipids and lipoprotein, lipid oxidation, and blood antioxidant enzymes in a rat hyperlipidemia model. Hyperlipidemic rats were treated with water extracts of either 0.5, 1.5 or 3.0 mg/kg fermented or unfermented Pu-erh tea. Serum low density lipoprotein-cholesterol (LDL-C) and triglyceride levels were significantly lowered by tea extract compared to the control group. ( p < 0.05) and in most cases were indistinguishable from rats fed normal chow, basal diet. Conversely, levels of high density lipoprotein-cholesterol (HDL-C) were elevated in the groups given daily doses of tea extract ( p < 0.05). Compared to the hyperlipidemic control group, activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in serum were significantly elevated in Pu-erh tea-treated groups while levels of malondiadehyde (a byproduct of lipid peroxidation) decreased in the same groups. These effects were most pronounced in the groups treated with the highest dose of fermented Pu-erh tea extract. Our results suggest that Pu-erh tea exerts strong antioxidative and lipid-lowering effects and therefore can be used to reduce the risk of cardiovascular disorders.