A Genome-Wide Microarray Highlights the Antiinflammatory Genes Targeted by Oolong Tea Theasinensin A in Macrophages

Changes in amino acids, catechins and alkaloids during the storage of oolong tea and their relationship with antibacterial effect

The storage process has a significant impact on tea quality. Few is known about effect of storage on quality of oolong tea. This study aimed to assess the effect of different storage times on the key chemical components of oolong tea by measuring changes in catechin, free amino acid, and alkaloid content. Variation in the main substances was determined by principal component analysis and heat map analysis. The results revealed notable effects of the storage process on the levels of theanine, epigallocatechin gallate (EGCG), and glutamine. These findings suggest that these compounds could serve as indicators for monitoring changes in oolong tea quality during storage. Additionally, the study observed an increase in the antibacterial ability of tea over time. Correlation analysis indicated that the antibacterial ability against Micrococcus tetragenus and Escherichia coli was influenced by metabolites such as aspartic acid, threonine, serine, gamma-aminobutyric acid, ornithine, alanine, arginine, and EGCG. Overall, this study presents an approach for identifying key metabolites to monitor tea quality effectively with relatively limited data.

The Changes in Metabolites, Quality Components, and Antioxidant Activity of Tea (Camellia sinensis) Infected with Exobasidium vexans by Applying UPLC-MS/MS-Based Widely Targeted Metabolome and Biochemical Analysis

Blister blight infection with Exobasidium vexans is one of the most destructive foliar diseases that seriously affect the quality and yield of tea. This research investigated the metabolite changes of healthy and infected leaves on tea cultivar 'Fuding Dabaicha' and further explored the potential antimicrobial substances against E. vexans infection. In total, 1,166 compounds were identified during the entire course of an infection, among which 73 different common compounds were significantly accumulated involved in the important antimicrobial substances of flavonoids and phenolic acids, including kaempferol (3,5,7,4'-tetrahydroxyflavone), kaempferol-3-O-sophoroside-7-O-glucoside, phloretin, 2,4,6-trihydroxybenzoic acid, galloylprocyanidin B4, and procyanidin C1 3'-O-gallate, which indicated that these metabolites might positively dominate resistance to E. vexans. Furthermore, relevant biological pathways, such as the flavone and flavonol biosynthesis, flavonoid biosynthesis, and phenylpropane pathways, were more closely related to resistance to E. vexans. Additionally, total flavonoids, phenolics, alkaloids, and terpenoids contributing to antimicrobial and antioxidant capacity were significantly altered during four different infection periods, especially the Leaf_S2 stage (the second stage of infection), in which the most concentration accumulated. The leaves affected by E. vexans infection at the second stage had the relatively highest antioxidant activity. Accordingly, this study provides a theoretical support for and comprehensive insights into the effects on the metabolite changes, tea quality components, and antioxidant activity of blister blight caused by E. vexans.

Regulatory Effects and Molecular Mechanisms of Tea and Its Active Compounds on Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disease, is a multifactorial disease resulting from the interaction between environment, genetic background, and metabolic stress. Most treatments for NAFLD include dietary intervention and exercise show limited efficacy due to the complex mechanisms involved in NAFLD. Meanwhile, drug therapy is accompanied by serious side effects. The development of high-efficiency natural supplements is a sustainable strategy for the prevention and treatment of NAFLD. As the second most consumed beverage, tea has health benefits that have been widely recognized. Nevertheless, the intervention of tea active compounds in NAFLD has received limited attention. Tea contains abundant bioactive compounds with potential effects on NAFLD, such as catechins, flavonoids, theanine, tea pigments, and tea polysaccharides. We reviewed the intrinsic and environmental factors and pathogenic mechanisms that affect the occurrence and development of NAFLD, and summarized the influences of exercise, drugs, diet, and tea drinking on NAFLD. On this basis, we further analyzed the potential effects and molecular regulatory mechanisms of tea active compounds on NAFLD and proposed future development directions. This review hopes to provide novel insights into the development and application of tea active compounds in the prevention and treatment of NAFLD.

The effect of oolong tea as an adjunct to nonsurgical management of chronic periodontitis: A randomized controlled clinical trial

Introduction: Oolong tea, a functional food, has numerous therapeutic benefits owing to the presence of bioactive polyphenols, theasinensins (TS) and catechins. The present study aimed to evaluate the influence of systemic administration of oolong tea as an adjunct to nonsurgical periodontal therapy (NSPT) in the management of chronic periodontitis (CP).Methods: A total of 60 subjects with mild to moderate CP were randomly divided into two groups of tests (n = 30) and the controls (n = 30). They underwent NSPT with adjunctive oolong tea supplementation in the test group only. At baseline, 1, and 3 months, their gingival index (GI), plaque index (PI), probing pocket depth (PPD), clinical attachment loss (CAL), percentage of sites with bleeding on probing (BOP), and lobene stain index (LSI) were recorded. Furthermore, the levels of glutathione peroxidase (GPx), total antioxidants (TAO), and malondialdehyde (MDA) were also estimated in gingival crevicular fluid (GCF), saliva and serum. Additionally, colony-forming units (CFUs) of selective supra and subgingival plaque bacteria were estimated in the plaque samples.Results: In both groups, at 1 month, the GI, PI, BOP, GPx, and TAO levels were improved with a reduction in the levels of MDA and CFU’s and no staining of teeth (P < 0.05). The results were maintained in the test group at 3-month recall visit.Conclusion: Adjunctive administration of oolong tea with NSPT reduced the local and systemic oxidative burden and rapidly resolved the inflammation in CP. This would be specifically beneficial in CP subjects with systemic conditions.

Assessment of Antioxidant, Immunomodulatory Activity of Oxidised Epigallocatechin-3-Gallate (Green Tea Polyphenol) and Its Action on the Main Protease of SARS-CoV-2—An In Vitro and In Silico Approach

Owing to the instability of Epigallocatechin Gallate (EGCG), it may undergo auto-oxidation and form oxidised products or dimers. In the present study, we aimed to evaluate the therapeutic effects, including antioxidation and immunomodulatory action, of the Oxidised Epigallocatechin Gallate (O-EGCG) as compared to native EGCG and the action of these compounds on main protease (Mpro) docking against SARS-CoV-2. HCT-116 (Human Colon Cancer) cell lines were used to estimate the total antioxidant capacity and lipid peroxidation levels and pro-inflammatory markers (human IL-6, IL-1β, TNF-α). Further, molecular docking analysis was performed by AutoDock and visualised in Discovery studio. Improved antioxidant capacity of O-EGCG was observed, and there was a significant decrease in the inflammatory markers (IL-1β, IL-6, and TNF-α) when O-EGCG was applied as compared to EGCG. The O-EGCG was shown to be strongly associated with the highest docking score and active site residues of IL-1, IL-6, and TNF- α, as well as the Mpro of SARS-CoV-2, according to in silico approach. The in vitro and in silico analyses indicate an improved therapeutic action of the oxidised form of EGCG. The effective inhibitory action of O-EGCG against SARS-CoV-2 suggests further exploration of the compound against COVID-19 and its efficacy. However, in vivo studies and understanding of the mechanism of action of O-EGCG may yield a better opinion on the use of O-EGCG and future human clinical trials.

Adsorption Equilibrium and Thermodynamics of Tea Theasinensins on HP20-A High-Efficiency Macroporous Adsorption Resin

The separation and preparation of theasinensins have been hot spots in the field of tea chemistry in recent years. However, information about the mechanism of efficient adsorption of tea theasinensins by resin has been limited. In this study, the adsorption equilibrium and thermodynamics of tea theasinensins by a high-efficiency macroporous adsorption HP20 resin were evaluated. The adsorption of theasinensin A, theasinensin B, and theasinensin C on HP20 resin were spontaneous physical reaction processes. Adsorption processes were exothermic processes, and lowering the temperature was beneficial to the adsorption. The Freundlich model was more suitable to describe the adsorption of tea theasinensins. The adsorption equilibrium constant and maximum adsorption capacity of theasinensin A were significantly higher than theasinensin B and theasinensin C, which indicated that the adsorption affinity of theasinensin A was stronger than that of theasinensin B and theasinensin C. The phenolic hydroxyl groups and intramolecular hydrogen bonds of theasinensin A were more than those of theasinensin B and theasinensin C, which might be the key to the resin's higher adsorption capacity for theasinensin A. The HP20 resin was very suitable for efficient adsorption of theasinensin A.

Understanding the Functional Activity of Polyphenols Using Omics-Based Approaches

Plant polyphenols are the main category of natural active substances, and are distributed widely in vegetables, fruits, and plant-based processed foods. Polyphenols have a beneficial performance in preventing diseases and maintaining body health. However, its action mechanism has not been well understood. Foodomics is a novel method to sequence and widely used in nutrition, combining genomics, proteomics, transcriptomics, microbiome, and metabolomics. Based on multi-omics technologies, foodomics provides abundant data to study functional activities of polyphenols. In this paper, physiological functions of various polyphenols based on foodomics and microbiome was discussed, especially the anti-inflammatory and anti-tumor activities and gut microbe regulation. In conclusion, omics (including microbiomics) is a useful approach to explore the bioactive activities of polyphenols in the nutrition and health of human and animals.

Tea bioactive components prevent carcinogenesis via anti-pathogen, anti-inflammation, and cell survival pathways

Cancer seriously impairs human health and survival. Many perturbations, such as increased oxidative stress, pathogen infection, and inflammation, promote the accumulation of DNA mutations, and ultimately lead to carcinogenesis. Tea is one of the most highly consumed beverages worldwide and has been linked to improvements in human health. Tea contains many active components, including tea polyphenols, tea polysaccharides, L-theanine, tea pigments, and caffeine among other common components. Several studies have identified components in tea that can directly or indirectly reduce carcinogenesis with some being used in a clinical setting. Many previous studies, in vitro and in vivo, have focused on the mechanisms that functional components of tea utilized to protect against cancer. One particular mechanism that has been well described is an improvement in antioxidant capacity seen with tea consumption. However, other mechanisms, including anti-pathogen, anti-inflammation and alterations in cell survival pathways, are also involved. The current review focuses on these anti-cancer mechanisms. This will be beneficial for clinical utilization of tea components in preventing and treating cancer in the future.

Condensed catechins and their potential health-benefits

Condensed catechins are commonly present in fermented tea, and are produced by the oxidation of monomeric catechins. Due to their auto-oxidation, catechins have diverse structural features, including different binding modes and degrees of polymerization. Because of their structural complexity, their physiological functions and possible health-benefits have not yet been fully investigated. This review focuses on the physiological potentials of dimeric and trimeric catechins in the intestine (regulation of absorption across the intestinal membrane), blood vessels (vasorelaxation in vessel regulation), and muscle organs (promotion of glucose uptake resulting in an anti-diabetic effect). Furthermore, the roles of non-absorbable theaflavins (dimeric catechins), absorbable theasinensins (dimeric catechins), and absorbable procyanidins (dimeric and trimeric catechins) on target organs are discussed.

Gene expression profiling and pathway network analysis of hepatic metabolic enzymes targeted by baicalein

ETHNOPHARMACOLOGICAL RELEVANCE

Baicalein is a flavone originally isolated from the roots of traditional Chinese medicinal herb, Scutellaria baicalensis, which has been proved as a promising chemopreventive compound for many chronic human diseases.

AIM OF THE STUDY

The present study aimed to clarify the molecular mechanism targeted by baicalein.

MATERIALS AND METHODS

Gene expression profiling of HepG2 cells treated with baicalein was carried out, using the Affymetrix 42K oligonucleotide microarray in the present study. Microarray data analyzed by Ingenuity Pathway Analysis (IPA), further study performed by real time PCR, reporter gene assay, and Western blot.

RESULTS

Among total 42K gene probes, baicalein treatment up-regulated the signals of 440 gene probes (1.04% of total gene probes) and down-regulated signals of 254 gene probes (0.6% of total gene probes) by ≥2-fold. These genes were categorized into 35 groups and hit for biological processes, molecular functions, and signaling pathways. The network and pathway analyses of these data further revealed that an Nrf2 (nuclear factor-erythroid 2 p45-related factor 2)-mediated ARE (antioxidant response element) pathway is involved in baicalein-induced gene expression of hepatic metabolic enzymes. The representative enzymes involved in Nrf2/ARE pathway were further confirmed at mRNA level by real time PCR and at protein level by Western blot analysis. Moreover, the ARE-reporter gene assay demonstrated that baicalein stimulated Nrf2-mediated ARE transactivation.

CONCLUSIONS

Our results provide a comprehensive data for understanding the hepatic metabolism, bioactive role and the molecular mechanisms of baicalein.