Compound In Green Tea Research Articles

EGCG attenuates METH self-administration and reinstatement of METH seeking in mice.

Methamphetamine (METH) use disorder is a chronic, relapsing disorder and involves frequent failures of self-control of drug seeking and taking. Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenolic compounds of green tea, which has shown great therapeutic effectiveness in neurological disorders. However, it is still unknown whether and how EGCG affects METH seeking behaviour. Here, we show nanostructured EGCG/ascorbic acid nanoparticles (EGCG/AA NPs) dose-dependently reduced METH self-administration (SA) under fixed-ratio 1 (FR1) and progressive ratio (PR) reinforcement schedules in mice and shifted METH dose-response curves downward. Furthermore, EGCG/AA NPs decreased drug- and cue-induced METH seeking. In addition, we found that METH SA led to a decrease in inhibitory postsynaptic currents (IPSCs) and increase in the AMPAR/NMDAR ratio and excitation/inhibition (E/I) ratio in ex vivo midbrain slices from ventral tegmental area (VTA) dopamine neurons. EGCG/AA NPs enhanced Gamma-aminobutyric acid (GABA)ergic inhibition and normalized the E/I ratio. EGCG restored the balance between excitation and inhibition in VTA dopamine neurons, which may contribute to the attenuation of METH SA. These findings indicate that EGCG is a promising pharmacotherapy for METH use disorder.

Epigallocatechin gallate effect on Interleukin-1 and MMP-9 expression as Pseudomonas aeruginosa keratitis adjuvant therapy

Link of Video Abstract: https://youtu.be/Ja9klXNlw5A Background: Keratitis Pseudomonas aeruginosa is the most frequently occurring eye infection. It is a rapidly developing condition that can lead to ocular infections (endophthalmitis) and corneal perforation resulting in vision loss. Although prompt administration of antibiotics can effectively kill the bacteria, the corneal damage caused by toxins persists. The following inflammatory process results in corneal thinning, fibrosis, and eventual perforation. Methods: This study is a literature review to support future experimental studies which will be conducted to examine the expression of IL-1b and MMP-9 on pseudomonas keratitis after administration of EGCG. Results: Interleukin-1ß is a proinflammatory cytokine secreted by various immune cells in response to acute and chronic inflammation. At the same time, matrix metalloproteinase (MMP) is a group of proteolytic enzymes involved in the pathophysiology of various ocular surface diseases. Epigallocatechin gallate (EGCG) is the major polyphenol compound in green tea, produced from the Camellia sinensis plant. Recent studies suggest that EGCG has anti-inflammatory and antioxidant effects on various cell types, including the cornea. EGCG inhibits IL-1β, which induces the activation of the NF-kB signaling pathway, which may explain the decrease in uPA expression and the reduction of collagen degradation by corneal fibroblasts. EGCG inhibits the activation of pro-MMP 9 produced by corneal fibroblasts in response to IL-1β stimulation, and this effect is mediated by the inhibition of uPA upregulation without a significant impact on pro-MMP 9 expressions. Conclusion: Epigallocatechin gallate (EGCG) in Camellia sinensis extract has the potential as an alternative adjuvant therapy for bacterial keratitis because it has antibacterial, anti-inflammatory and antioxidant effects.

Targeting fibrotic signaling pathways by EGCG as a therapeutic strategy for uterine fibroids

Fibrosis is characterized by excessive accumulation of extracellular matrix, which is a key feature of uterine fibroids. Our prior research supports the tenet that inhibition of fibrotic processes may restrict fibroid growth. Epigallocatechin gallate (EGCG), a green tea compound with powerful antioxidant properties, is an investigational drug for uterine fibroids. An early phase clinical trial showed that EGCG was effective in reducing fibroid size and its associated symptoms; however, its mechanism of action(s) has not been completely elucidated. Here, we probed effects of EGCG on key signaling pathways involved in fibroid cell fibrosis. Viability of myometrial and fibroid cells was not greatly affected by EGCG treatment (1–200 µM). Cyclin D1, a protein involved in cell cycle progression, was increased in fibroid cells and was significantly reduced by EGCG. EGCG treatment significantly reduced mRNA or protein levels of key fibrotic proteins, including fibronectin (FN1), collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1), connective tissue growth factor (CTGF), and actin alpha 2, smooth muscle (ACTA2) in fibroid cells, suggesting antifibrotic effects. EGCG treatment altered the activation of YAP, β-catenin, JNK and AKT, but not Smad 2/3 signaling pathways involved in mediating fibrotic process. Finally, we conducted a comparative study to evaluate the ability of EGCG to regulate fibrosis with synthetic inhibitors. We observed that EGCG displayed greater efficacy than ICG-001 (β-catenin), SP600125 (JNK) and MK-2206 (AKT) inhibitors, and its effects were equivalent to verteporfin (YAP) or SB525334 (Smad) for regulating expression of key fibrotic mediators. These data indicate that EGCG exhibits anti-fibrotic effects in fibroid cells. These results provide insight into mechanisms behind the observed clinical efficacy of EGCG against uterine fibroids.

Inflammation inhibitory activity of green tea, soybean, and guava extracts during Sars-Cov-2 infection through TNF protein in cytokine storm

Coronavirus disease is caused by the pathogen severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) known as COVID-19. COVID-19 has caused the deaths of 6,541,936 people worldwide as of September 27th, 2022. SARS-CoV-2 severity is determined by a cytokine storm condition, in which the innate immune system creates an unregulated and excessive production of pro-inflammatory such IL-1, IL-6, NF Kappa B, and TNF alpha signaling molecules known as cytokines. The patient died due to respiratory organ failure and an acute complication because of the hyper-inflammation phenomenon. Green tea, soybean, and guava bioactive substances are well-known to act as anti-inflammation, and antioxidants become prospective COVID-19 illness candidates to overcome the cytokine storm. Our research aims to discover the bioactivity, bioavailability, and protein targets of green tea, soybean, and guava bioactive compounds as anti-inflammatory agents via the TNF inhibition pathway. The experiment uses in silico methods and harnesses the accessible datasets. Samples of 3D structure and SMILE identity of bioactive compounds were retrieved from the KNApSAck and Dr Duke databases. The QSAR analysis was done by WAY2DRUG web server, while the ADME prediction was performed using SWISSADME web server, following the Lipinsky rules of drugs. The target protein and protein-protein interaction were analyzed using STRING DB and Cytoscape software. Lastly, molecular docking was performed using Autodock 4.2 and visualization with BioVia Discovery Studio 2019. The identified study showed the potential of green tea, soybean, and guava’s bioactive compounds have played an important role as anti-inflammation agents through TNF inhibitor pathway.

Effect of phenolic compounds Extraction of Green tea (Camellia sinsis. L) On the Glutathione of Alloxan Experimental InducedDiabeticRabbit.

Diabetes Mellitus is considered as a member of oxidative stress syndrome. It is associated with an imbalance between types of free radicals and scavenger's system. This study showed the effect of the polyphenol compounds extracted from green tea (Camellia Sinesis L) on alloxan induced diabetic rabbits to determine their role in treatment of diabetes mellitus, their effect on enzymatic antioxidant and to know the histological effects on the diabetic kidney. The rabbits group was divided into five groups, cach group consist of 10 rabbits. The blood and tissue samples from these groups were taken for analysis and the result were as follow: There was a significant increase in Glucose .when polyphenol extract of green tea was used gave a significant decrease in all parameters (p<0.05) with dose rate of 100mg/kg of body weigt,200mgrkg of body weight as compared with diabetic group. There was a significant decrease in glutathione. When polyphenol extract of green tea was used with dose rate 100mg /kg of body weight gave a significant increase (p<0.05) in all parameters as compared with diabetic group.In comparison between the efficacy of herbs polyphenol compound in green tea. glibeneclamide it was appeared that the herbs are the better based on ¢ cy on treatment of diabetes and their effect on glucose and glutathione. The present results revealed that alloxan was effectively induced diabetes by partial destruction of b-cells of pancreas which lead to elevation of bload glucose level. As a consequence of hyperglycemia the abnormal effect was obvious in certain tissues in the body which attributed to the effect of diabetes Histological investigations shows that all the lesions in the kidney that result from diabetes such as hypertrophy, degeneration and hylanosis of the glomeruli.

Study on the Effects of Processes on Aroma Compounds in Rizhao Green Tea Based on the Gas Chromatography-Ion Mobility Spectrometry

Tea processing plays an important role in the formation of tea aroma. In order to explore the composition and variation in aroma during Rizhao green tea processing, gas chromatography-ion mobility spectrometry was employed to investigate the formation and changes of tea aroma in four processing stages. A total of 62 volatile compounds were identified, including alcohols, aldehydes, ketones, esters, terpenes, and oxygen compounds. Relative odor activity value was used to identify 17 characteristic aroma compounds. The main aromatic compounds of chestnut-like aroma were linalool, pentanal, hexanal, heptanal, octanal, nonanal, 2-methylbutanal, 3-methylbutanal, 3-methylthiopropanal, and methyl 2-methylbutanoate. There were significant changes in the volatile components at different processing stages. Samples of tea leaves and green tea had special aroma characteristics, while samples of fixated and rolled leaves had similar aroma compounds. The results are beneficial for the improvement of the flavor and quality of Rizhao green tea. Practical Application. Tea is the world’s most consumed nonalcoholic beverage, with a multitude of health-promoting benefits, such as antioxidant, antiobesity, and antiallergic activities. At present, the research on the aroma compounds of Rizhao green tea mainly focuses on the aroma characteristics of finished tea and the aroma differences of different kinds of commercial tea. This study explored the effects of the processes on aroma compounds, and the results provide a theoretical reference for the improvement of tea processing technology, tea quality control, and evaluation methods.

Potential protective function of green tea polyphenol EGCG against high glucose-induced cardiac injury and aging

Green tea and its active extracts have been widely used in a variety of dietary supplements. However, to date, the interaction of these bioactive compounds in green tea and their protein targets are not well studied. We first used the bioinformatics analysis of the relevant diabetes-related targets with the green tea bioactive compounds target proteins to construct a protein interaction (PPI) network to screen the core targets. The results of in vitro experiments showed that EGCG, a major polyphenolic component of green tea, inhibited HG-induced cardiomyocyte hypertrophy, inflammation, oxidative stress response, and cellular senescence. It was found that the PPARG-dependent pathways were involved in the protective effects of EGCG against HG-induced myocardial injury and senescence. This study comprehensively explored the role of EGCG in high glucose-induced myocardial cell injury and aging.

Effects of leaf-spreading on the volatile aroma components of green tea under red light of different intensities

Spreading is an indispensable process in the aroma formation of green tea. The application of exogenous red-light spreading in tea processing has been verified to significantly improve the aroma of green tea, and endow tea with freshness, sweet flavor, and mellow taste. However, there were no previous studies investigating the effects of spreading with different red-light intensities on the aroma components of green tea. The aim of the present study was to evaluate the effect of the relationship between the aroma component and spreading with different red-light intensities (300 μmol∙m−2∙s−1, 150 μmol∙m−2∙s−1 and 75 μmol∙m−2∙s−1). As a result, a total of ninety-one volatile components were identified in this study. The orthogonal partial least squares discriminant analysis (OPLS-DA) model clearly distinguished the volatile components of green tea between different red-light intensities and obtained thirty-three differential volatile compounds. Combined with odor activity value (OAV > 1) analysis revealed that eleven volatile components were the key volatile compounds of green tea under different light conditions. Among them, 3-methyl-butanal, (E)-nerolidol, and linalool were the sources of chestnut-like aroma in green tea and were significantly accumulated under medium (MRL) and low intensity (LRL) red light. The results of the present study provided a theoretical basis that could guide green tea processing with red-light intensities to increase the aroma quality components of green tea.

Targeting the TNF-α–TNFR interaction with EGCG to block NF-κB signaling in human synovial fibroblasts

The tumor necrosis factor alpha (TNF-α)–TNF-α receptor (TNFR) interaction plays a central role in the pathogenesis of various autoimmune diseases, particularly rheumatoid arthritis, and is therefore considered a key target for drug discovery. However, natural compounds that can specifically block the TNF-α–TNFR interaction are rarely reported. (-)-Epigallocatechin-3-gallate (EGCG) is the most active, abundant, and thoroughly investigated polyphenolic compound in green tea. However, the molecular mechanism by which EGCG ameliorates autoimmune arthritis remains to be elucidated. In the present study, we found that EGCG can directly bind to TNF-α, TNFR1, and TNFR2 with similar μM affinity and disrupt the interactions between TNF-α and TNFR1 and TNFR2, which inhibits TNF-α-induced L929 cell death, blocks TNF-α-induced NF-κB activation in 293-TNF-α response cell line, and eventually leads to inhibition of TNF-α-induced NF-κB signaling pathway in HFLS and MH7A cells. Thus, regular consumption of EGCG in green tea may represent a potential therapeutic agent for the treatment of TNF-α-associated diseases.

Epigallocatechin Gallate (EGCG), an Active Phenolic Compound of Green Tea, Inhibits Tumor Growth of Head and Neck Cancer Cells by Targeting DNA Hypermethylation

Head and neck cancers are among the deadliest cancers, ranked sixth globally in rates of high mortality and poor patient prognoses. The prevalence of head and neck squamous cell carcinoma (HNSCC) is associated with smoking and excessive alcohol consumption. Despite several advances in diagnostic and interventional methods, the morbidity of subjects with HNSCC has remained unchanged over the last 30 years. Epigenetic alterations, such as DNA hypermethylation, are commonly associated with several cancers, including HNSCC. Thus, epigenetic changes are considered promising therapeutic targets for chemoprevention. Here, we investigated the effect of EGCG on DNA hypermethylation and the growth of HNSCC. First, we assessed the expression levels of global DNA methylation in HNSCC cells (FaDu and SCC-1) and observed enhanced methylation levels compared with normal human bronchial epithelial cells (NHBE). Treatment of EGCG to HNSCC cells significantly inhibited global DNA hypermethylation by up to 70-80% after 6 days. Inhibition of DNA hypermethylation in HNSCC cells was confirmed by the conversion of 5-methylcytosine (5-mc) into 5-hydroxy methylcytosine (5hmC). DNA methyltransferases regulate DNA methylation. Next, we checked the effect of EGCG on the expression levels of DNA methyltransferases (DNMTs) and DNMT activity. Treatment of EGCG to HNSCC cells significantly reduced DNMT activity to 60% in SCC-1 and 80% in FaDu cells. The protein levels of DNMT3a and DNMT3b were downregulated in both cell lines after EGCG treatment. EGCG treatment to HNSCC cells reactivated tumor suppressors and caused decreased cell proliferation. Our in vivo study demonstrated that administration of EGCG (0.5%, w/w) as a supplement within an AIN76A diet resulted in inhibition of tumor growth in FaDu xenografts in nude mice (80%; p < 0.01) compared with non-EGCG-treated controls. The growth inhibitory effect of dietary EGCG on the HNSCC xenograft tumors was associated with the inhibition of DNMTs and reactivation of silenced tumor suppressors. Together, our study provides evidence that EGCG acts as a DNA demethylating agent and can reactivate epigenetically silenced tumor suppressors to inhibit the growth of HNSCC cells.

In vitro biological evaluation of epigallocatechin gallate (EGCG) release from three-dimensional printed (3DP) calcium phosphate bone scaffolds.

Three-dimensional printed (3DP) tricalcium phosphate (TCP) scaffolds can guide bone regeneration, especially for patient-specific defect repair applications in low-load bearing sites. Epigallocatechin gallate (EGCG), a green tea compound, has gained attention as a safer alternative treatment for bone disorders. The 3DP TCP scaffold is designed for localized EGCG delivery, which can enhance in vitro osteogenic ability, anti-osteoclastogenic activity, vascularization formation, and chemoprevention. In the cocultures of human bone marrow-derived mesenchymal stem cells (hMSCs) and monocytes (THP-1), EGCG release enhances osteogenic differentiation of hMSCs at day 16 compared to the control; this is indicated by a 2.8- and 4.0-fold upregulation of Runt-related transcription factor 2 (Runx2) and bone gamma-carboxyglutamic acid-containing protein (BGLAP), the early and late osteoblast differentiation marker expressions. However, EGCG significantly downregulates the receptor activator of nuclear factor-κB ligand (RANKL) expression by 7.0-fold, indicating that EGCG suppresses RANKL-induced osteoclast maturation. EGCG also stimulates endothelial tube formation at as early as 3 hours when human umbilical vein endothelial cells (HUVECs) grow on Matrigel. It reduces human osteosarcoma MG-63 cell viability by 66% compared to the control at day 11. An in vitro release kinetics study demonstrates that EGCG shows a ∼64% release within a day followed by a sustained release in the physiological environment (pH 7.4) because its phenolic hydroxyl groups are easily deprotonated at physiological pH. These findings contribute to developing a multifunctional scaffold for the treatment of low load-bearing patient-specific bone defects after trauma and tumor excision.

POTENSI DAUN TEH HIJAU (Camellia sinensis) SEBAGAI INHIBITOR MAIN PROTEASE (Mpro) COVID-19: SEBUAH STUDI MOLECULAR DOCKING

Green tea is an herbal plant that has active compounds including anti-inflammatory, antioxidant, anti-allergic, and antiviral compounds. A previous study, flavonoid compound in tea leaves has been proven as antiviral. The development of effective antiviral drugs against COVID-19 remains a challenge for researchers across the world. A previous study investigated the role of the main protease enzyme (Mpro) which is useful in the viral life cycle as a promising drug target. This study aims to know the potential compounds of green tea leaves as a COVID-19 Mpro inhibitor using molecular docking. 12 compounds and lopinavir were used. Lipinski analysis was carried out to assess potential compounds as a drug. Docking was carried out by Autodock Tools 1.5.6 and Autodock Vina. The visualization was carried out by Discovery Studio v16. The results showed that all compounds compiled the criteria as a drug based on Lipinski rules. Catechin and epicatechin have the same energy bond as lopinavir with a binding energy of -7.1 kcal/mol. Catechin gallate and epicatechin gallate have the strongest energy bond with a binding energy of -9.0 and -8.2 kcal/mol. All compounds bind in the active site of the COVID-19 Mpro so they are competitive inhibitor. Catechin gallate is the strongest inhibitors.

HS-SPME/GC-MS Reveals the Season Effects on Volatile Compounds of Green Tea in High-Latitude Region.

This study investigates the volatile compounds of green tea produced with different leaves from spring, summer, and autumn in high−latitude region. A total of 95 volatile compounds were identified by gas chromatography–mass spectrometry (GC–MS). Spring, summer and autumn green tea contained 68, 72 and 82 volatile compounds, respectively. Principal component analysis (PCA), partial least squares−discrimination analysis (PLS−DA), and hierarchical cluster analysis (HCA) classified the samples and showed the difference. And 32 key characteristic components were screened out based on variable importance in the projection (VIP) values higher than 1.0. The characteristic volatile compounds of spring green tea including 18 components, such as geranylacetone, phenethyl alcohol, geraniol, β−ionone, jasmone, 1−octen−3−ol and longifolene. 13 components such as 2−methylfuran, indole, 1−octanol, D−limonene and ethanethiol were the key compounds in summer green tea. And 2,4,6−trimethylstyrene was the major differential volatile compounds in autumn green tea. The results increase our knowledge of green tea in different seasons and provide a theoretical basis for production control of green tea.

Effect of fixation methods and various clones of Camellia sinensis var. sinensis (L) properties and antioxidant activity of Indonesian green tea

Fixation is essential in green tea processing to inactivate the polyphenol oxidase enzyme. In Indonesia, green tea is made from the Assam variety and produced using the panning method. Few studies are reported on green tea made from Indonesian clones of the Sinensis variety. This study aims to identify chemical characteristics, antioxidant activity, and sensory evaluation of green tea from local clones of the Sinensis variety (GMBS 2, GMBS 4, and GMBS 5) with different fixation methods (panning and steaming). The results show that the caffeine content of green tea products ranged from 2.51-2.59% and 2.67-2.74% for panning and steaming methods. The panning method produced green tea with higher total polyphenol and flavonoid content than the steaming method. Green tea with the panning method has an IC50 value of 14.45; 14.41; and 17.41 mg/L for GMBS 2, GMBS 4, and GMBS 5, respectively. The panning method resulted in a smaller IC50 value than the steaming method for GMBS 2 and GMBS 4 clones. The steaming method produced green tea with a higher taste, aroma, and total score than those the panning method. However, different fixation methods did not significantly affect the appearance, liquor color, and leaf infusion. In conclusion, different fixation methods on GMBS 2, GMB 4, and GMB 5 produced green tea products that met the Indonesian National Standard 3945:2016. Further research is needed to determine the role of the plucking period/season and the characteristics of volatile compounds of green tea from GMBS clones with different fixation methods.

Sensory-Guided Identification and Characterization of Kokumi-Tasting Compounds in Green Tea (Camellia sinensis L.).

The chemical substances responsible for the kokumi taste of green tea infusion are still unclear. Here, we isolated the kokumi compound-containing fractions from green tea infusion through ultrafiltration, and the major kokumi compounds were characterized as γ-Glu-Gln and γ-Glu-Cys-Gly (GSH) through ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS). The results indicated that peptides and amino acids were essential compounds in the kokumi-enriched fractions for conducting the sense of kokumi. L-theanine had an enhancing effect on the kokumi taste of green tea infusion, which was confirmed in the sensory reconstitution study. Thus, peptides, especially γ-Glu-Gln and GSH, are the major kokumi compounds in green tea infusion, which has the potential of improving the flavor of tea beverages.

Analysis of metabolites in green tea during the roasting process using non-targeted metabolomics.

Roasting plays an important role in the formation of flavor of roasted green tea; however, the changes in chemicals during this process have not been systematically studied until now. To reveal the dynamic changes in chemicals in green tea during roasting, non-targeted metabolomics, coupled with chemometrics, was employed. A total of 101 non-volatile metabolites were identified in tea samples, and 29 metabolites were identified as characteristic metabolites of roasting. A significant increase in catechins and their derivatives, organic acids, and flavonoid glycosides was observed, while the content of some amino acids and their derivatives decreased over 50% during roasting. The content of theanine glucoside increased dramatically (by 21.23-fold at the roasting stage), and Maillard-derived compounds also increased to varying degrees. Glycosylation, oxidative polymerization, and pyrolysis were important reactions responsible for the formation and transformation of flavor compounds in roasted green tea during roasting. © 2022 Society of Chemical Industry.

Epigallocatechin-3-Gallate Pretreatment Improves Autologous Adipose-derived Stem Cells Against Rheumatoid Arthritis-induced Neuroinflammation in the Brain of Collagen-induced Rats.

Adipose tissue-derived mesenchymal stem cells (ADSC) exert neuroprotective and anti-inflammatory effects. ADSCs are considered potential therapeutics for rheumatoid arthritis (RA), an inflammatory, multisystemic autoimmune disease. Epigallocatechin-3-gallate (EGCG), the major polyphenolic compound in green tea, has strong anti-inflammatory and antioxidant properties. This study aimed to investigate whether EGCG has a synergistic effect on the neuroprotective effects of ADSCs to protect the RA-damaged brain. Wistar rats were classified into four groups: sham, RA, RA + ADSCs (1 × 106 cells per rat), and RA + EGCG (10µM)-pretreated ADSCs. After 2months of treatment, the brain tissues from the rats were collected and investigated. The brains of RA rats had higher inflammation and apoptosis. ADSC treatment ameliorated these negative effects significantly; however, the neuroprotective abilities of EGCG-pretreated ADSCs were significantly higher than ADSCs. Furthermore, the RA-induced repression of the PI3K/Akt survival pathway was reactivated by EGCG-pretreated ADSCs. Collectively, this study provides evidence that EGCG synergistically enhances the neuroprotective ability of ADSCs to repress the negative effects of RA on the brain. These findings could help develop new therapeutic strategies against RA or other neurodegenerative diseases after clinical validation in the future.

Changes in the metabolite composition and enzyme activity of fermented tea during processing

As the dominant microbial strain in Fuzhuan brick tea, Eurotium cristatum (E. cristatum) can biotransform the fermentation substrate during growth and reproduction, and in so doing enhance the tea’s health benefits. Green tea contains a large number of bioactive compounds with antihypertensive potential. However, as a nonfermented tea, inactivation of various enzymes (such as polyphenol oxidase) during processing results in a single secondary metabolite with limited health effects. The novel fermented tea we studied was processed by solid-state fermentation (SSF) with E. cristatum, and the substrate was a mixture of green tea and Radix Puerariae (RP). This study was aimed at evaluating the multiple effects by E. cristatum during fermentation. Compared to the unfermented control groups, the sample groups secreted enzymes (such as polyphenol oxidase and α-amylase), and the bioactive compounds content of sample groups changed, as well as significantly higher inhibition of Angiotensin-converting enzyme (ACE) in vitro (which also implies greater antihypertensive potential). These results will help further investigations of the antihypertensive bioactive compounds of green tea and the fermentation potential of E. cristatum.

Effect of Fixation Methods on Biochemical Characteristics of Green Teas and Their Lipid-Lowering Effects in a Zebrafish Larvae Model.

Fixation is a key process contributing to different flavors of green tea and pan-fire and steam were the common fixation methods applied conventionally. In this study, pan-fired green tea (PGT) and steamed green tea (SGT) produced by different fixation methods were compared in characteristic biochemicals including volatile compounds, amino acids, catechins and alkaloids, together with evaluating their tastes and lipid-lowering effects. PGT and SGT could be distinguished clearly by orthogonal partial least squares discriminant analysis (OPLS-DA) and heatmap. SGT had higher contents of volatile alcohols (44.75%) with green and floral attributes, while PGT had higher contents of volatile esters (22.63%) with fruity and sweet attributes. Results of electronic tongue analysis showed that PGT and SGT had similar taste of strong umami and sweetness, but little astringency and bitterness. In addition, amino acids were more abundant in PGT (41.47 mg/g in PGT, 33.79 mg/g in SGT), and catechins were more abundant in SGT (111.36 mg/g in PGT, 139.68 mg/mg in SGT). Zebrafish larvae high-fat model was applied to study the lipid-lowering effects of PGT and SGT. Results showed that both SGT and PGT had lipid-lowering effects, and the lipid level was decreased to 61.11 and 54.47% at concentration of 300 mg/L compared to high-fat group, respectively. Generally, different fixation methods of pan-fire and steam showed significant effects on aroma and contents of characteristic chemical compounds (amino acids and catechins) of green tea, but no effects on the taste and lipid-lowering activity.

The Potential of Epigallocatechin Gallate (EGCG) in Targeting Autophagy for Cancer Treatment: A Narrative Review.

Autophagy is an evolutionarily conserved process for the degradation of redundant or damaged cellular material by means of a lysosome-dependent mechanism, contributing to cell homeostasis and survival. Autophagy plays a multifaceted and context-dependent role in cancer initiation, maintenance, and progression; it has a tumor suppressive role in the absence of disease and is upregulated in cancer cells to meet their elevated metabolic demands. Autophagy represents a promising but challenging target in cancer treatment. Green tea is a widely used beverage with healthy effects on several diseases, including cancer. The bioactive compounds of green tea are mainly catechins, and epigallocatechin-gallate (EGCG) is the most abundant and biologically active among them. In this review, evidence of autophagy modulation and anti-cancer effects induced by EGCG treatment in experimental cancer models is presented. Reviewed articles reveal that EGCG promotes cytotoxic autophagy often through the inactivation of PI3K/Akt/mTOR pathway, resulting in apoptosis induction. EGCG pro-oxidant activity has been postulated to be responsible for its anti-cancer effects. In combination therapy with a chemotherapy drug, EGCG inhibits cell growth and the drug-induced pro-survival autophagy. The selected studies rightly claim EGCG as a valuable agent in cancer chemoprevention.