Ingredient Of Green Tea Research Articles

Epigallocatechin-3-gallate protects bovine ruminal epithelial cells against lipopolysaccharide-induced inflammatory damage by activating autophagy

BackgroundSubacute ruminal acidosis (SARA) causes an increase in endotoxin, which can induce immune and inflammatory responses in the ruminal epithelium of dairy cows. In non-ruminants, epigallocatechin-3-gallate (EGCG), a major bioactive ingredient of green tea, is well-known to alleviate inflammation. Whether EGCG confers protection against SARA-induced inflammation and the underlying mechanisms are unknown.ResultsIn vivo, eight ruminally cannulated Holstein cows in mid-lactation were randomly assigned to either a low-concentrate (40%) diet (CON) or a high-concentrate (60%) diet (HC) for 3 weeks to induce SARA (n = 4). Cows with SARA had greater serum concentrations of tumor necrosis factor (TNF)-α and interleukin-6, and epithelium had histological signs of damage. In vitro, immortalized bovine ruminal epithelial cells (BREC) were treated with lipopolysaccharide (LPS) to imitate the inflammatory damage caused by SARA. Our data revealed that BREC treated with 10 µg/mL LPS for 6 h successfully induce a robust inflammatory response as indicated by increased phosphorylation of IκBα and nuclear factor kappa-B (NF-κB) p65. Pre-treatment of BREC with 50 µmol/L EGCG for 6 h before LPS challenge promoted the degradation of NLR family pyrin domain containing 3 (NLRP3) inflammasome through activation of autophagy, which further repressed activation of NF-κB pathway targeting Toll-like receptor 4 (TLR4). Analyses also revealed that the ECGG upregulated tight junction (TJ) protein expression upon incubation with LPS.ConclusionsSubacute ruminal acidosis causes ruminal epithelium injury and systemic inflammation in dairy cows. However, the anti-inflammatory effects of EGCG help preserve the integrity of the epithelial barrier through activating autophagy when BREC are exposed to LPS. Thus, EGCG could potentially serve as an effective therapeutic agent for SARA-associated inflammation.Graphical

Epigallocatechin gallate alleviates non-alcoholic fatty liver disease through the inhibition of the expression and activity of Dipeptide kinase 4

BackgroundNon-alcoholic fatty liver disease (NAFLD) has emerged as the most prevalent glocal cause of chronic hepatic disease, with incidence rates that continue to rise steadily. Treatment options for affected patients are currently limited to dietary changes and exercise interventions, with no drugs having been licensed for the treatment of this disease. There is thus a pressing need for the development of novel therapeutic strategies. Work from our group suggests that the primary bioactive ingredient in green tea, epigallocatechin gallate (EGCG), may help reduce liver fat content and protect against hepatic injury through the inhibition of dipeptidyl peptidase 4 (DPP4) expression and activity. The study investigated the potential pathways by which EGCG may improve NAFLD, identified the sites of interaction between EGCG and DPP4, and proposed novel clinical treatment strategies. MethodsA clinical randomized controlled trial was conducted to investigate the potential efficacy of EGCG in NAFLD patients. The study compared relevant indices before and after EGCG administration. Animal models of NAFLD were constructed using male C57BL/6J mice fed a high-fat diet to observe the ameliorative effects of EGCG on the livers of the model mice and to investigate the potential pathways by which EGCG alleviates NAFLD. The interaction mechanism between EGCG and DPP4 was investigated using oleic acid and palmitic acid-treated HepG2 cell lines. Plasmids in which different sites had been disrupted were used to identify the effective interaction sites. ResultsECGC was found to suppress the accumulation of lipids, inhibit inflammation, remediate dysregulated lipid metabolism, and improve the pathogenesis of NAFLD via the inhibition of the expression and activity of DPP4. ConclusionsThe study results indicate that EGCG has a positive impact on improving NAFLD. These results highlight promising new opportunities to safely and effectively treat NAFLD in the clinic. Study id numberChiCTR2300076741; https://www.chictr.org.cn/

Abstract LB_C22: Dynamic interactions of disordered N-terminal domain of p53 in cancer

Abstract TP53 is mutated in over half of all human cancers, making it the most important tumor suppressor. p53 sequence includes an N-terminal domain (NTD), a DNA binding domain (DBD), and others. NTD is intrinsically disordered and interacts with many proteins, acting as a hub for cellular signaling. Using a combination of computational and experimental approaches, we show NTD have dynamic interactions with cyclophilin D (CypD), a mitochondria proline isomerase with key roles in cellular necrosis and mitochondrial energy metabolism. We show that a subset of p53 truncation mutations can promote cancer cell proliferation and mitochondrial metabolism in a CypD-dependent manner. Although dynamic interfaces are often considered “undruggable”, we have demonstrated that EGCG, the active ingredient of green tea, can bind to NTD and disrupt NTD-CypD interaction, inhibiting the effects of p53 truncation mutants. Our studies point to a novel mechanism for p53 gain-of-function (GOF) mutations through NTD interaction with mitochondrial CypD. Our data also provide novel insights into dynamic interactions of intrinscially disordered proteins and small molecule engagement of such challenging drug targets, with important implications for cancer treatment. Citation Format: Chunyu Wang, Baines Christopher, Jianhan Chen, Stewart Loh. Dynamic interactions of disordered N-terminal domain of p53 in cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_C22.

Acute effects of (-)-gallocatechin gallate-rich green tea extract on the cerebral hemodynamic response of the prefrontal cortex in healthy humans.

The benefits of long-term consumption of green tea on the brain are well known. However, among many ingredients of green tea, the acute effects of (-)-gallocatechin gallate-rich green tea extract (GCG-GTE), have received comparatively less attention. Herein, we investigated the acute effects of oral ingestion of green tea with GCG-GTE, which contains close replicas of the ingredients of hot green tea, on task-dependent hemodynamics in the prefrontal cortex of healthy adult human brains. In this randomized, double-blind, placebo-controlled, parallel group trial, 35 healthy adults completed computerized cognitive tasks that demand activation of the prefrontal cortex at baseline and 1 h after consumption of placebo and 900 mg of GCG-GTE extract supplement. During cognitive testing, hemodynamic responses (change in HbO2 concentration) in the prefrontal cortex were assessed using functional near-infrared spectroscopy (fNIRS). In fNIRS data, significant group x session interactions were found in the left (p = 0.035) and right (p = 0.036) dorsolateral prefrontal cortex (DLPFC). In behavioral data, despite the numerical increase in the GCG-GTE group and the numerical decrease in the Placebo group, no significant differences were observed in the cognitive performance measure between the groups. The result suggests a single dose of orally administered GCG-GTE can reduce DLPFC activation in healthy humans even with increased task demand. GCG-GTE is a promising functional material that can affect neural efficiency to lower mental workload during cognitively demanding tasks. However, further studies are needed to verify this.

Natural Products in Renal-Associated Drug Discovery.

The global increase in the incidence of kidney failure constitutes a major public health problem. Kidney disease is classified into acute and chronic: acute kidney injury (AKI) is associated with an abrupt decline in kidney function and chronic kidney disease (CKD) with chronic renal failure for more than three months. Although both kidney syndromes are multifactorial, inflammation and oxidative stress play major roles in the diversity of processes leading to these kidney malfunctions. Here, we reviewed various publications on medicinal plants with antioxidant and anti-inflammatory properties with the potential to treat and manage kidney-associated diseases in rodent models. Additionally, we conducted a meta-analysis to identify gene signatures and associated biological processes perturbed in human and mouse cells treated with antioxidants such as epigallocatechin gallate (EGCG), the active ingredient in green tea, and the mushroom Ganoderma lucidum (GL) and in kidney disease rodent models. We identified EGCG- and GL-regulated gene signatures linked to metabolism; inflammation (NRG1, E2F1, NFKB1 and JUN); ion signalling; transport; renal processes (SLC12A1 and LOX) and VEGF, ERBB and BDNF signalling. Medicinal plant extracts are proving to be effective for the prevention, management and treatment of kidney-associated diseases; however, more detailed characterisations of their targets are needed to enable more trust in their application in the management of kidney-associated diseases.

Biochemical, hematological, peripheral smear and weight evaluation of low dose Epigallocatechin Gallate in Diethylnitrosamine administered rats

Background: Currently, with the development of technology, the use of many chemicals especially Diethylnitrosamine (DEN) in agriculture and industry has increased. The polyphenolic compounds of Epigallocatechin gallate (EGCG) is the active ingredient of green tea. It has been reported that green tea has antioxidant effects. In this study, effects of low dose Epigallocatechin gallate (EGCG), against exposure of Diethylnitrosamine administered rats. 
 Methods: As a group, groups were divided into five groups of ten rats for the application as Control, Sham, DEN EGCG and DEN+EGCG. The parameters analyzed are hemogram, biochemical, peripheral smear and weight. 
 Results: DEN injection has significantly increased LDH, AST, ALT and ALP values, Which are signs of hepatocyte injuries. The number of WBCs increased in the EGCG group. In terms of HDL and TChol levels, the group in which DEN+EGCG were applied together was found to be the highest and TG and LDL levels were found to be lowest. The current study will be a comprehensive study demonstrating the effects of low-dose EGCG against DEN-administred rats.

Development and Optimisation of Inhalable EGCG Nano-Liposomes as a Potential Treatment for Pulmonary Arterial Hypertension by Implementation of the Design of Experiments Approach.

Epigallocatechin gallate (EGCG), the main ingredient in green tea, holds promise as a potential treatment for pulmonary arterial hypertension (PAH). However, EGCG has many drawbacks, including stability issues, low bioavailability, and a short half-life. Therefore, the purpose of this research was to develop and optimize an inhalable EGCG nano-liposome formulation aiming to overcome EGCG's drawbacks by applying a design of experiments strategy. The aerodynamic behaviour of the optimum formulation was determined using the next-generation impactor (NGI), and its effects on the TGF-β pathway were determined using a cell-based reporter assay. The newly formulated inhalable EGCG liposome had an average liposome size of 105 nm, a polydispersity index (PDI) of 0.18, a zeta potential of -25.5 mV, an encapsulation efficiency of 90.5%, and a PDI after one month of 0.19. These results are in complete agreement with the predicted values of the model. Its aerodynamic properties were as follows: the mass median aerodynamic diameter (MMAD) was 4.41 µm, the fine particle fraction (FPF) was 53.46%, and the percentage of particles equal to or less than 3 µm was 34.3%. This demonstrates that the novel EGCG liposome has all the properties required to be inhalable, and it is expected to be deposited deeply in the lung. The TGFβ pathway is activated in PAH lungs, and the optimum EGCG nano-liposome inhibits TGFβ signalling in cell-based studies and thus holds promise as a potential treatment for PAH.

Increased expression of androgen receptor and PSA genes in LNCaP (prostate cancer) cell line due to high concentrations of EGCG, an active ingredient in green tea.

Androgen receptor (AR) play a key role in the onset and progression of prostate cancer. Epigallocatechin-3-gallate (EGCG) is a polyphenolic compound and the active ingredient in green tea, which is involved in modulating gene expression through epigenetic alterations. Previous studies have shown that EGCG at low concentrations reduces the expression of AR and prostate-specific antigen (PSA) in the LNCaP cell line of prostate cancer. In this study, the effect of higher EGCG concentrations on AR and PSA expression in LNCaP prostate cancer cell line was investigated. In this study, LNCaP prostate cancer cell line was used and after MTT test, concentrations of 40, 60 and 80μg/mL EGCG were used for treatment. Then, the expression of AR and PSA genes was evaluated by RT-PCR. AR protein expression was also assessed by Western blotting. The present study showed that treatment of LNCaPs cells by EGCG reduces cell proliferation. The IC50 value was 42.7μg/mL under experimental conditions. It was also observed that EGCG at concentrations of 40 and 80μg/mL increased the expression of AR and PSA (p<0.05). The present study showed that the effect of EGCG on AR expression was different at different concentrations, so that unlike previous studies, higher concentrations of EGCG (80 and 40μg/mL) increased AR and PSA expression. It seems that due to the toxic effects of EGCG in high concentrations on cancer cells and the possibility of its effect on normal cells, more caution should be exercised in its use.

Epigallocatechin Gallate Attenuates Gentamicin-Induced Nephrotoxicity by Suppressing Apoptosis and Ferroptosis

Gentamicin (GEN) is a kind of aminoglycoside antibiotic with the adverse effect of nephrotoxicity. Currently, no effective measures against the nephrotoxicity have been approved. In the present study, epigallocatechin gallate (EG), a useful ingredient in green tea, was used to attenuate its nephrotoxicity. EG was shown to largely attenuate the renal damage and the increase of malondialdehyde (MDA) and the decrease of glutathione (GSH) in GEN-injected rats. In NRK-52E cells, GEN increased the cellular ROS in the early treatment phase and ROS remained continuously high from 1.5 H to 24 H. Moreover, EG alleviated the increase of ROS and MDA and the decrease of GSH caused by GEN. Furthermore, EG activated the protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). After the treatment of GEN, the protein level of cleaved-caspase-3, the flow cytometry analysis and the JC-1 staining, the protein levels of glutathione peroxidase 4 (GPX4) and SLC7A11, were greatly changed, indicating the occurrence of both apoptosis and ferroptosis, whereas EG can reduce these changes. However, when Nrf2 was knocked down by siRNA, the above protective effects of EG were weakened. In summary, EG attenuated GEN-induced nephrotoxicity by suppressing apoptosis and ferroptosis.

Epigallocatechin-3-Gallate Improves Intestinal Gut Microbiota Homeostasis and Ameliorates Clostridioides difficile Infection.

Clostridioides difficile infection is closely related to the intestinal flora disorders induced by antibiotics, and changes in the intestinal flora may cause the occurrence and development of Clostridioides difficile infection. Epigallocatechin-3-gallate (EGCG) is one of the major bioactive ingredients of green tea and has been suggested to alleviate the growth of C. difficile in vitro. EGCG can ameliorate several diseases, such as obesity, by regulating the gut microbiota. However, whether EGCG can attenuate C. difficile infection by improving the gut microbiota is unknown. After establishing a mouse model of C. difficile infection, mice were administered EGCG (25 or 50 mg/kg/day) or PBS intragastrically for 2 weeks to assess the benefits of EGCG. Colonic pathology, inflammation, the intestinal barrier, gut microbiota composition, metabolomics, and the transcriptome were evaluated in the different groups. Compared with those of the mice in the CDI group, EGCG improved survival rates after infection, improved inflammatory markers, and restored the damage to the intestinal barrier. Furthermore, EGCG could improve the intestinal microbial community caused by C. difficile infection, such as by reducing the relative abundance of Enterococcaceae and Enterobacteriaceae. Moreover, EGCG can increase short-chain fatty acids, improve amino acid metabolism, and downregulate pathways related to intestinal inflammation. EGCG alters the microbiota and alleviates C. difficile infection, which provides new insights into potential therapies.

EGCG protects the mouse brain against cerebral ischemia/reperfusion injury by suppressing autophagy via the AKT/AMPK/mTOR phosphorylation pathway.

Stroke remains one of the leading reasons of mortality and physical disability worldwide. The treatment of cerebral ischemic stroke faces challenges, partly due to a lack of effective treatments. In this study, we demonstrated that autophagy was stimulated by transient middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R). Treatment with (−)-epigallocatechin-3-gallate (EGCG), a bioactive ingredient in green tea, was able to mitigate cerebral ischemia/reperfusion injury (CIRI), given the evidence that EGCG administration could reduce the infarct volume and protect poststroke neuronal loss in MCAO/R mice in vivo and attenuate cell loss in OGD/R-challenged HT22 cells in vitro through suppressing autophagy activity. Mechanistically, EGCG inhibited autophagy via modulating the AKT/AMPK/mTOR phosphorylation pathway both in vivo and in vitro models of stroke, which was further confirmed by the results that the administration of GSK690693, an AKT/AMPK inhibitor, and rapamycin, an inhibitor of mTOR, reversed aforementioned changes in autophagy and AKT/AMPK/mTOR signaling pathway. Overall, the application of EGCG relieved CIRI by suppressing autophagy via the AKT/AMPK/mTOR phosphorylation pathway.

An Exploratory Evaluation of a Low Dose Theanine Consumption on Improving Sleep in Middle-Aged and Older Males

L-theanine (theanine), one of the ingredients of green tea, had been proven to have anti-anxiety, anti-stress, memory, cognitive, and sleep improvement effects in most clinical trials. However, these effects have shown efficacy at a dose of 200–400 mg of theanine a day. In this study, we explored the sleep-improving effects of a lower dose (100 mg/day) of theanine. A double-blind, randomized crossover study was conducted on 25 middle-aged and older males. Participants were randomly assigned to Groups A and B. Group A took theanine first, and Group B took theanine later in the intervention period. The participants took theanine/placebo for one week. Electroencephalogram (EEG) parameters were measured with a monitoring device during sleep, and subjective sleep quality after waking up was evaluated using a questionnaire. Following the statistical analysis between interventions, subgroup analyses according to the participants’ background information were conducted on the representative sleep parameters of non-REM sleep, REM sleep, and wakefulness. Of the 25 participants, three withdrew from this study. In the sleep analysis, there was no significant difference in all sleep parameters between the theanine and placebo periods. In particular, the difference in the percentage of nonREM sleep in stage 2 per sleep duration was not significant (p = 0.053). However, subgroup analysis of the results showed that the percentage of non-REM sleep in stage 2 in groups aged &lt;50 years was higher in theanine than that of the placebo, and in groups with green tea consumption habit of &lt;3 to 4 days per week (p = 0.018, 0.048). The intake of 100 mg/day of theanine does not have an effect on sleep improvement. However, subgroup analyses showed that theanine had an improved effect in stage 2 non-REM sleep according to age and green tea consumption habit.

Epigallocatechin Gallate (EGCG) Mitigates The Effect of Camptothecin‐Induced Oxidative Stress on Bone Cancer‐like cells (UMR 106‐01 BSP) by Inhibiting Apoptosis

Many medical treatments have been proposed and utilized to mitigate the effects of oxidants on mammalian cells. Some studies have demonstrated the antioxidative effects of EGCG (an active ingredient in green tea) against cellular oxidants such as camptothecin (CAMPT). However, not many studies have shown how EGCG mitigates the effects of CAMPT on UMR cells. We hypothesized that EGCG mitigates the effects of CAMPT on cell proliferation and biophysical parameters in UMR cells by inhibiting CAMPT‐induced apoptosis. Briefly, UMR cells were routinely passaged, counted, plated at 4.8 x 105 cells/mL in six‐well culture plates, then treated with varying concentrations of CAMPT. The cultures were incubated for 72 hours at 37°C + 5% CO₂ infusion. Cells were subsequently counted to establish the proliferation and viability of the induced cells as compared to controls. In another experiment, designated UMR cells were co‐treated with CAMPT and different concentrations of EGCG then processed, as mentioned above, to evaluate whether or not the EGCG treatment was able to mitigate the oxidative effect of CAMPT through proliferation / viability studies. Apoptosis markers were assessed for each experiment by using a Caspase‐3/CPP32 Colorimetric Assay Kit. Lastly, designated cells were treated with CAMPT alone, or CAMPT +EGCG then assessed using electric cell‐substrate impedance sensing (ECIS) technology to explore the effects of the chemicals used on key biophysical parameters of UMR cells (i.e. cell membrane resistance, rate of cell spreading and cell attachment). Briefly, CAMPT‐treated and CAMPT+EGCG‐treated UMR cells were plated at 2.5 x 105 cells/mL in eight‐well ECIS array plates. The plates were placed into the ECIS array holder and incubated at 37°C with 5% CO₂. The biophysical parameters (cell membrane resistance/impedance, cell spreading, cell attachment) were monitored and measured in real‐time for 48 hours, using the ECIS instrument. F test ANOVA was used to compare variances between all trials and all values in the results were expressed as means ±SD. The results of the proliferation study showed a decrease in CAMPT‐treated UMR cell proliferation in a concentration‐dependent manner (Figure 1). Cells co‐treated with CAMPT + EGCG revealed that EGCG was able to reverse the oxidative effects of CAMPT on the UMR cells in a concentration‐dependent manner *Figure 2). The Caspase‐3/CPP32 Colorimetric Assay showed an increase in apoptotic marker activity from the CAMPT‐induced samples in contrast with the uninduced controls. The ECIS technology documented decreases in biophysical parameters in the UMR cells when CAMPT alone was used. Co‐treatment of the cells with CAMPT+EGCG showed a reverse effect on the biophysical parameters. F‐Test ANOVA yielded statistically significant values with p values &lt;0.05. The results of this research suggest that EGCG is effective in protecting UMR cells from oxidative stress by inhibiting apoptosis. Moreover, results from the ECIS instrument validates this technology as a corroborator of the biological effects of CAMPT and EGCG on UMR cells. This study suggests that EGCG has a protective role in mitigating oxidative stress in mammalian cells.

The effectiveness of green tea and sonophoresis on oily skin: a case report

Background: Oily skin can be extremely problematic for sufferersand presents a great challenge for cosmetologists. This condition is characterized by an excessive amount of sebum on epidermal surface and enlarged skin pores.Modern cosmetology is able to offer a wide range of treatments that are able to reduce excess sebum secretion, and an appropriate diagnosis and cosmetic interview will allow for the selection of a suitable cosmetic treatment. If there are no contraindications for device treatments and the client is not allergic to cosmetic products, an ultrasound treatment called sonophoresis may be used. Green tea is obtained from both the leaves and buds of the Camellia sinensis plant. The active ingredients of green tea are polyphenols, which have antimicrobial, anti-inflammatory, and antineoplastic properties. Thanks to modern cosmetic devices, we are able to use green tea and sonophoresis to introduce this preparation into the skin. Aim of the study: The aim of this study was to evaluate the effectiveness of a sonophoresis treatment on oily skin in a 20-year-old female. Case report:The participant reported issues with too much sebum on the epidermis. The sebum level was measured before and after a series ofsonophoresistreatments using a sebumeter (DermaUnitSCC3). For the treatment, an ultrasound device and a cosmetic ampoule containing green tea extract were used. The entire cosmetic procedure consisted of 4 treatments performed at weekly intervals. Conclusions: After the series of cosmetological treatments, there was a significant reduction in sebum secretion.Thus, the use ofsonophoresis and a green tea ampoule turned out to be a great help in reducing epidermal sebum. The participant also noticed that her skin had less sheenfollowing the series of treatments.The resultsindicate that the sonophoresis procedure is safe and effective.

Epigallocatechin-3-gallate + L-theanine/β-cyclodextrin inclusion complexes enhance epigallocatechin-3-gallate bioavailability and its lipid-lowering and weight loss effects

• EGCG + LTA/βCD inclusion complexes prevented EGCG digestion in vitro . • EGCG + LTA/βCD increased EGCG bioaccessibility and antioxidant activity. • EGCG + LTA/βCD increased gut micro-diversity and lipid metabolism genera in vivo . • EGCG + LTA/βCD enhanced the lipid-lowering and weight loss effects of EGCG in vivo . Epigallocatechin-3-gallate (EGCG) and L-theanine (LTA), which are active ingredients in green tea, can inhibit fat accumulation; however, EGCG bioavailability is <5%. Here, we aimed to improve EGCG bioavailability and efficacy by preparing EGCG + LTA/β-cyclodextrin (βCD) inclusion complexes by freeze-drying EGCG + LTA at their mass ratio (5:1) in green tea. Physicochemical characterisation revealed that the supramolecular EGCG + LTA/βCD inclusion complexes had distinct crystal structures formed via intermolecular hydrogen bonding. The inclusion complexes prevented simulated EGCG digestion in vitro while increasing its bioaccessibility and antioxidant activity ( p < 0.05). In rats fed a high-fat diet, EGCG + LTA/βCD inclusion complexes significantly increased gut microflora diversity and the abundance of lipid metabolism-related genera but decreased the abundance of EGCG catabolism-related genera. Furthermore, the inclusion complexes significantly enhanced the lipid-lowering and weight loss effects of EGCG in vivo ( p < 0.05), likely by improving gut microflora and EGCG bioavailability.

Edible Green Solvent for Optimized Catechins Extraction from Green Tea Leaves: Anti-Hypercholesterolemia.

Catechin polyphenols are the major bioactive ingredients in green tea with various human health benefits. Extraction of catechins from green tea (GTE) leaves at optimized standard conditions is still a challenging approach. An optimized, rapid, and economic extraction method is industrially needed. We hypothesized that certain extraction techniques in the presence of natural polymers and antioxidants might improve GTE catechin extraction yield and its biological activity. The effect of microwave (30–60 seconds irradiation in a typical kitchen microwave) assisted extraction (MAE) and ultrasonic assisted extraction (UAE) techniques were evaluated separately and in combination. To study the effect of the extraction solvent, nine edible green solvent combinations were investigated namely water, ascorbic acid, chitosan/ascorbic acid, carboxymethylcellulose /ascorbic acid, methylcellulose /ascorbic acid, chitosan/methylcellulose/ascorbic acid, methylcellulose, chitosan/acetic acid, and ethanol. The amounts of extracted catechins from green tea leaves were quantified with HPLC-UV.Data showed that the use of MAE & UAE technique was the optimal in producing a higher extraction yield of catechins. Chitosan/ascorbic acid was the optimized solvent with high extraction efficiencies of catechins. Studies in high fat diet fed animals demonstrated significant reduction of total cholesterol and LDL-C by GTE after 3 weeks of oral daily administration. In conclusion, efficient extraction, and stabilization of catechins from green tea leaves demonstrated a significant lowering of high fat diet-mediated elevation in blood cholesterol and LDL-C levels.

EGCG inhibits growth of tumoral lesions on lip and tongue of K-Ras transgenic mice through the Notch pathway

Epigallocatechin-3-gallate (EGCG), the main active ingredient of green tea, exhibits low toxic side effect and versatile bioactivities, and its anti-cancer effect has been extensively studied. Most of the studies used cancer cell lines and xenograft models. However, whether EGCG can prevent tumor onset after cancer-associated mutations occur is still controversial. In the present study, Krt14-cre/ERT-Kras transgenic mice were developed and the expression of K-RasG12D was induced by tamoxifen. Two weeks after induction, the K-Ras mutant mice developed exophytic tumoral lesions on the lips and tongues, with significant activation of Notch signaling pathway. Administration of EGCG effectively delayed the time of appearance, decreased the size and weight of tumoral lesions, relieved heterotypic hyperplasia of tumoral lesions, and prolonged the life of the mice. The Notch signaling pathway was significantly inhibited by EGCG in the tumoral lesions. Furthermore, EGCG significantly induced cell apoptosis and inhibited the proliferation of tongue cancer cells by blocking the activation of Notch signaling pathway. Taken together, these results indicate EGCG as an effective chemotherapeutic agent for tongue cancer by targeting Notch pathway.

Theanine Improves High-Dose Epigallocatechin-3-Gallate-Induced Lifespan Reduction in Caenorhabditis elegans.

Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea. Our previous report showed that induced hormesis was a critical determinant for the promotion of a healthy lifespan in Caenorhabditis elegans. In the present study, we investigated the anti-aging effects of the main active ingredients in green tea. We found that galloylated catechins (EGCG and epicatechin gallate) could extend the lifespan of C. elegans, while their metabolites (gallic acid, epicatechin, and epigallocatechin) could not. Interestingly, the combination with theanine, not caffeine, could alleviate the adverse effects induced by high-dose EGCG, including the promotion of lifespan and locomotor ability. This was due to the attenuation of the excess production of reactive oxygen species and the activation of DAF-16. These findings will facilitate further studies on the health benefits of tea active components and their interactions.

Protective Effect of Epigallocatechin-3-Gallate (EGCG) in Diseases with Uncontrolled Immune Activation: Could Such a Scenario Be Helpful to Counteract COVID-19?

Some coronavirus disease 2019 (COVID-19) patients develop acute pneumonia which can result in a cytokine storm syndrome in response to Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection. The most effective anti-inflammatory drugs employed so far in severe COVID-19 belong to the cytokine-directed biological agents, widely used in the management of many autoimmune diseases. In this paper we analyze the efficacy of epigallocatechin 3-gallate (EGCG), the most abundant ingredient in green tea leaves and a well-known antioxidant, in counteracting autoimmune diseases, which are dominated by a massive cytokines production. Indeed, many studies registered that EGCG inhibits signal transducer and activator of transcription (STAT)1/3 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) transcription factors, whose activities are crucial in a multiplicity of downstream pro-inflammatory signaling pathways. Importantly, the safety of EGCG/green tea extract supplementation is well documented in many clinical trials, as discussed in this review. Since EGCG can restore the natural immunological homeostasis in many different autoimmune diseases, we propose here a supplementation therapy with EGCG in COVID-19 patients. Besides some antiviral and anti-sepsis actions, the major EGCG benefits lie in its anti-fibrotic effect and in the ability to simultaneously downregulate expression and signaling of many inflammatory mediators. In conclusion, EGCG can be considered a potential safe natural supplement to counteract hyper-inflammation growing in COVID-19.

Epigallocatechin gallate reverses gastric cancer by regulating the long noncoding RNA LINC00511/miR-29b/KDM2A axis

Epigallocatechin gallate (EGCG), as one of the main ingredients of green tea, has been reported to have potential prevention on a variety of solid tumors. However, the system-wide molecular mechanisms targeted to EGCG's anti-tumor effect have not been illustrated. Here, AGS and SGC7901 GC cells were used to investigate the EGCG-mediated change of gene expression. Our data showed that EGCG retarded cell growth and promoted cell death of GC in dose-dependent manner. Analyses based on transcription, translation as well as function were performed to explore the elusive anticancer role of EGCG. Of them, cell cycle was probably implicated key pathway of EGCG. Besides, our data revealed numerous LncRNAs activated after EGCG treatment. In this study, LINC00511 was discovered to be suppressed by EGCG and highly expressed in GC cells and tissues. Knockdown of LINC00511 inhibited cell growth and promoted cell death ratio in GC. Additionally, our data suggested LINC00511 could decrease the expression of miR-29b, followed by inducing GC development. Knockdown of miR-29b recovered the effects of LINC00511 silencing. In addition, we found overexpression of KDM2A, a target of miR-29b, would rescue the level of LINC00511. All the data showed that the LINC00511/miR-29b/KDM2A axis can be used as a diagnostic and therapeutic target for GC.