Epigallocatechin-3-gallate Treatment Research Articles

Epigallocatechin gallate protects MC3T3-E1 cells from cadmium-induced apoptosis and dysfunction via modulating PI3K/AKT/mTOR and Nrf2/HO-1 pathways

Epigallocatechin gallate (EGCG), an active constituent of tea, is recognized for its anticancer and anti-inflammatory properties. However, the specific mechanism by which EGCG protects osteoblasts from cadmium-induced damage remains incompletely understood. Here, the action of EGCG was investigated by exposing MC3T3-E1 osteoblasts to EGCG and CdCl2 and examining their growth, apoptosis, and differentiation. It was found that EGCG promoted the viability of cadmium-exposed MC3T3-E1 cells, mitigated apoptosis, and promoted both maturation and mineralization. Additionally, CdCl2 has been reported to inhibit both the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) and nuclear factor erythroid 2-related factor 2/heme oxygenase-1(Nrf2/HO-1) signaling pathways. EGCG treatment attenuated cadmium-induced apoptosis in osteoblasts and restored their function by upregulating both signaling pathways. The findings provide compelling evidence for EGCG’s role in attenuating cadmium-induced osteoblast apoptosis and dysfunction through activating the PI3K/AKT/mTOR and Nrf2/HO-1 pathways. This suggests the potential of using EGCG for treating cadmium-induced osteoblast dysfunction.

De Novo Elastin Assembly Alleviates Development of Supravalvular Aortic Stenosis.

A series of incurable cardiovascular disorders arise due to improper formation of elastin during development. Supravalvular aortic stenosis (SVAS), resulting from a haploinsufficiency of ELN, is caused by improper stress sensing by medial vascular smooth muscle cells, leading to progressive luminal occlusion and heart failure. SVAS remains incurable, as current therapies do not address the root issue of defective elastin. We use SVAS here as a model of vascular proliferative disease using both human induced pluripotent stem cell-derived vascular smooth muscle cells and developmental Eln± mouse models to establish de novo elastin assembly as a new therapeutic intervention. We demonstrate mitigation of vascular proliferative abnormalities following de novo extracellular elastin assembly through the addition of the polyphenol epigallocatechin gallate to SVAS human induced pluripotent stem cell-derived vascular smooth muscle cells and in utero to Eln± mice. We demonstrate de novo elastin deposition normalizes SVAS human induced pluripotent stem cell-derived vascular smooth muscle cell hyperproliferation and rescues hypertension and aortic mechanics in Eln± mice, providing critical preclinical findings for the future application of epigallocatechin gallate treatment in humans.

Epigallocatechin gallate (EGCG) alleviates inflammation and endothelial dysfunction and improves pregnancy outcomes in preeclampsia (PE)-like rats via eNOS/Nrf2/HO-1 pathway

Background and purposeEpigallocatechin gallate (EGCG), a natural antioxidant, has shown protective effect in many diseases. We explore the effect and potential regulatory mechanisms of EGCG in preeclampsia (PE)-like rats. Methods and materialsPE was mimicked in pregnant rats. EGCG was orally administered at a dosage of 25(Low, L) or 50mg/kg (High, H) from gestational day (GD) 6 to 17. The blood pressure signatures, heart rates were monitored. The 24-h proteinuria and serum were analyzed. On GD 18, rats were sacrificed, and pups and placentas were weighed. Kidneys and placentas were analyzed using immunohistochemistry (IHC) and hematoxylin-eosin staining (H&E). Placentas were examined using western blot for sFlt1, eNOS, Nrf2, HO-1, SLC7A11. MDA, GSH, GPx and Fe2+ were measured. ResultsEGCG inhibits systolic blood pressure, BUN, CREA, ALT, AST, UA and proteinuria levels in PE-like rats. EGCG enhances the pup weight and crown-rump length and reduces the rate of fetus growth restriction in PE group. Endothelial dysfunction and infiltration of inflammatory cells were found in kidney cortex and placenta tissues in PE group and were inhibited by EGCG treatment. sFlt1 was activated in placentas in PE group and inhibited by EGCG while eNOS/Nrf2/HO-1 were inhibited in PE group and restored by EGCG. MDA and Fe concentrations were elevated in PE group and reduced by EGCG while the GSH level, SLC7A11 and the GPx activity were inhibited in PE group and restored by EGCG. ConclusionEGCG alleviates inflammation, endothelial dysfunction and placental ferroptosis, improves pregnancy outcomes in PE-like rats via eNOS/Nrf2/HO-1.

High glucose reduces Nrf2-dependent cRAGE release and enhances inflammasome-dependent IL-1β production in monocytes: the modulatory effects of EGCG

Soluble receptor for advanced glycation end products (sRAGE) acts as a decoy sequestering of RAGE ligands, thus preventing the activation of the ligand-RAGE axis linking human diseases. However, the molecular mechanisms underlying sRAGE remain unclear. In this study, THP-1 monocytes were cultured in normal glucose (NG, 5.5 mmol/L) and high glucose (HG, 15 mmol/L) to investigate the effects of diabetes-relevant glucose concentrations on sRAGE and interleukin-1β (IL-1β) secretion. The modulatory effects of epigallocatechin gallate (EGCG) in response to HG challenge were also evaluated. HG enhanced intracellular reactive oxygen species (ROS) generation and RAGE expression. The secretion of sRAGE, including esRAGE and cRAGE, was reduced under HG conditions, together with the downregulation of a disintegrin and metallopeptidase 10 (ADAM10) and nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation. Mechanistically, the HG effects were counteracted by siRAGE and exacerbated by siNrf2. Chromatin immunoprecipitation results showed that Nrf2 binding to the ADAM10 promoter and HG interfered with this binding. Our data reinforce the notion that RAGE and Nrf2 might be sRAGE-regulating factors. Under HG conditions, the treatment of EGCG reduced ROS generation and RAGE activation. EGCG-stimulated cRAGE release was likely caused by the upregulation of the Nrf2-ADAM10 pathway. EGCG inhibited HG-mediated NLRP3 inflammasome activation at least partly by stimulating sRAGE, thereby reducing IL-1β release.

Effect of Epigallocatechin Gallate on the Inflammatory Response in Mice (Mus musculus) Kidneys

Background: Epigallocatechin gallate is the primary polyphenol constituent of green tea. It has the ability to inhibit the pathological processes caused by oxidants. However, in certain cases, the green tea diet is known to exert pro-oxidant effects. In addition, studies have shown that epigallocatechin gallate negatively affects cells. Several studies on epigallocatechin gallate showed increased oxidative stress and decreased intracellular antioxidants. Furthermore, it can stimulate an inflammatory response from the innate immune system, which may contribute to the elimination of the effects of epigallocatechin gallate. Purpose: This study aims to investigate the inflammatory responses (IL-1, IL-6, and TNF-α) in mice kidneys due to epigallocatechin gallate. Methods: This study involved the use of experimental animals aged between two and three months with an average body weight of 20 grams. The animals were randomly divided into two groups, namely the control group and the epigallocatechin gallate treatment group, with each group consisting of 16 samples. The dose of epigallocatechin gallate used in this study was 750 mg/kg bw. The treatment was administered for three days, after which the kidneys were collected. Immunohistochemical staining was used to observe the inflammatory response, including IL-1, IL-6 and TNF-α. Subsequently, all the data were collected and statistically analyzed using an independent t-test. Results: The results of the data analysis showed a significant difference in the expression of IL-6 (p = 0.018) and TNF-α (p = 0.000), but no significant difference in the expression of IL-1 (p = 0.106). Conclusion: In conclusion, epigallocatechin gallate was found to induce an inflammatory response in mice kidneys.

Epigallocatechin gallate suppresses mitotic clonal expansion and adipogenic differentiation of preadipocytes through impeding JAK2/STAT3-mediated transcriptional cascades

BackgroundMitotic clonal expansion (MCE) is a prerequisite for preadipocyte differentiation and adipogenesis. Epigallocatechin gallate (EGCG) has been shown to inhibit preadipocyte differentiation. However, the exact molecular mechanisms are still elusive. PurposeThis study investigated whether EGCG could inhibit adipogenesis and lipid accumulation by regulating the cell cycle in the MCE phase of adipogenesis and its underlying molecular mechanisms. Method3T3-L1 preadipocytes were induced to differentiate by a differentiation cocktail (DMI) and were treated with EGCG (25–100 μM) for 9, 18, and 24 h to examine the effect on MCE, or eight days to examine the effect on terminal differentiation. C57BL/6 mice were fed a high-fat diet (HFD) for three months to induce obesity and were given EGCG (50 or 100 mg/kg) daily by gavage. ResultsWe showed that EGCG significantly inhibited terminal adipogenesis and lipid accumulation in 3T3-L1 cells and decreased expressions of PPARγ, C/EBPα, and FASN. Notably, at the MCE phase, EGCG regulated the cell cycle in sequential order, induced G0/G1 arrest at 18 h, and inhibited the G2/M phase at 24 h upon DMI treatment. Meanwhile, EGCG regulated the expressions of cell cycle regulators (cyclin D1, cyclin E1, CDK4, CDK6, cyclin B1, cyclin B2, p16, and p27), and decreased C/EBPβ, PPARγ, and C/EBPα expressions at MCE. Mechanistic studies using STAT3 agonist Colivelin and antagonist C188–9 revealed that EGCG-induced cell cycle arrest in the MCE phase and terminal adipocyte differentiation was mediated by the inhibition of JAK2/STAT3 signaling cascades and STAT3 (Tyr705) nuclear translocation. Furthermore, EGCG significantly protected mice from HFD-induced obesity, reduced body weight and lipid accumulations in adipose tissues, reduced hyperlipidemia and leptin levels, and improved glucose intolerance and insulin sensitivity. Moreover, RNA sequencing (RNA-seq) analysis showed that the cell cycle changes in epididymal white adipose tissue (eWAT) were significantly enriched upon EGCG treatment. We further verified that EGCG treatment significantly reduced expressions of adipogenic factors, cell cycle regulators, and p-STAT3 in eWAT. ConclusionEGCG inhibits MCE, resulting in the inhibition of early and terminal adipocyte differentiation and lipid accumulation, which were mediated by inhibiting p-STAT3 nucleus translocation and activation.

Abstract 521: Anticancer mechanisms of epigallocatechin gallate revealed via cellular and molecular profiling

Abstract Introduction: Epigallocatechin gallate (EGCG) is a polyphenol present in green tea that is known for its anti-oxidant, anti-inflammatory, anti-angiogenic, pro-apoptotic, and anti-cancer properties. However, EGCG has not been systematically evaluated on a large panel of cancer cell lines. We hypothesized that EGCG exhibits varying effects on specific cancer cell genetic backgrounds and types. This study aimed to provide a comprehensive analysis of EGCG on both cell viability and gene expression profiles. Methods: 750 cancer cell lines were cultured and seeded in 1536-well plates for cell viability studies (by the CTD2 Center at the Broad Institute). After 24 h, cells were treated with 16 two-fold serial dilutions of EGCG. After 72 h, cell viability was assayed using CellTiter-Glo. For gene expression profiling (with the Broad Institute and NIH), 8 cell lines were treated with 10 µM EGCG for 6 and 24 h, and transcriptomes were assessed using Affymetrix GeneChip Human Genome U133 Plus 2.0 Arrays. The CMap large-scale transcriptome dataset was used for comparisons. Results: EGCG had the highest potency in the non-Hodgkins B-cell lymphoma cell line DoHH2 (IC50=0.42 µM), the myeloid leukemia cell line Ku812 (IC50=3.76 µM), and the multiple myeloma cell line KMS-28BM (IC50=4.57 µM). Tissue-of-origin analysis showed that EGCG was most potent against lymphoid cancers, and least potent against prostate cancers. Bioinformatics-based analyses found that EGCG-treated cells resembled cells overexpressing CHEK2, DDP4, CBLC, ZNF350, and TRAF6, and cells underexpressing TRIM16. EGCG-induced gene expression resembled lapatinib and sulfasalazine treatment. Conclusions: This study provides a comprehensive examination of the differential impact of EGCG treatment on cancer cells. Subsequent research on the timing and duration of the changes, along with pathway enrichment analyses, will potentially guide the translational potential of EGCG and its chemical analogs in personalized cancer treatment approaches. Citation Format: Aria Panchal, Jacqueline H. Law, Clement Lo, Kenneth W. Yip. Anticancer mechanisms of epigallocatechin gallate revealed via cellular and molecular profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 521.

Epigallocatechin-3-gallate-induced tolerance to cadmium stress involves increased flavonoid synthesis and nutrient homeostasis in tomato roots

Cadmium (Cd) is a toxic heavy metal, increasingly accumulating in the environment and its presence in various environmental compartments represents a significant risk to human health via the food chain. Epigallocatechin-3-Gallate (EGCG) is a prominent secondary metabolite, which can safeguard plants from biotic and abiotic stress. However, the role of EGCG in flavonoid synthesis, nutrient acquisition and reactive oxygen species (ROS) metabolism under Cd stress remains unclear. Here, we examined the effects of EGCG and Cd treatment on leaf photochemical efficiency, cell ultrastructure, essential element acquisition, antioxidant system, and secondary metabolism in tomato (Solanum lycopersicum L.). The results showed that O2•−, H2O2, and malondialdehyde levels increased after Cd treatment, but Fv/Fm decreased significantly, suggesting that Cd induced oxidative stress and photoinhibition. However, EGCG mitigated the adverse effects of Cd-induced phytotoxicity in both the roots and leaves. A decrease in ROS accumulation under EGCG + Cd treatment was mainly attributed to the significant enhancement in antioxidant enzyme activity, flavonoid content, and PHENYLALANINE AMMONIA-LYASE expression in roots. Moreover, EGCG reduced Cd content but increased some essential nutrient contents in tomato plants. Transmission electron microscopy-based observations revealed that EGCG treatment safeguards leaf and root cell ultrastructure under Cd stress. This implies that tomato plants subjected to Cd stress experienced advantageous effects upon receiving EGCG treatment. The present work elucidated critical mechanisms by which EGCG induces tolerance to Cd, thereby providing a basis for future investigations into environmentally sustainable agricultural practices in areas contaminated with heavy metals, for utilizing naturally occurring substances found in plants.

Epigallocatechin gallate improves neuronal damage in animal model of ischemic stroke and glutamate-exposed neurons via modulation of hippocalcin expression.

Epigallocatechin gallate (EGCG) is a polyphenolic component of green tea that has anti-oxidative and anti-inflammatory effects in neurons. Ischemic stroke is a major neurological disease that causes irreversible brain disorders. It increases the intracellular calcium concentration and induces apoptosis. The regulation of intracellular calcium concentration is important to maintain the function of the nervous system. Hippocalcin is a neuronal calcium sensor protein that controls intracellular calcium concentration. We investigated whether EGCG treatment regulates the expression of hippocalcin in stroke animal model and glutamate-induced neuronal damage. We performed middle cerebral artery occlusion (MCAO) to induce cerebral ischemia. EGCG (50 mg/kg) or phosphate buffered saline was injected into the abdominal cavity just before MCAO surgery. The neurobehavioral tests were performed 24 h after MCAO surgery and cerebral cortex tissue was collected. MCAO damage induced severe neurobehavioral disorders, increased infarct volume, and decreased the expression of hippocalcin in the cerebral cortex. However, EGCG treatment improved these deficits and alleviated the decrease in hippocalcin expression in cerebral cortex. In addition, EGCG dose-dependently alleviated neuronal cell death and intracellular calcium overload in glutamate-exposed neurons. Glutamate exposure reduced hippocalcin expression, decreased Bcl-2 expression, and increased Bax expression. However, EGCG treatment mitigated these changes caused by glutamate toxicity. EGCG also attenuated the increase in caspase-3 and cleaved caspase-3 expressions caused by glutamate exposure. The effect of EGCG was more pronounced in non-transfected cells than in hippocalcin siRNA-transfected cells. These findings demonstrate that EGCG protects neurons against glutamate toxicity through the regulation of Bcl-2 family proteins and caspase-3. It is known that hippocalcin exerts anti-apoptotic effect through the modulation of apoptotic pathway. Thus, we can suggest evidence that EGCG has a neuroprotective effect by regulating hippocalcin expression in ischemic brain damage and glutamate-exposed cells.

The antibacterial mechanism of (-)-epigallocatechin-3-gallate (EGCG) against Campylobacter jejuni through transcriptome profiling.

(-)-Epigallocatechin-3-gallate (EGCG) has been shown antibacterial activity against Campylobacter jejuni; however, the relevant antibacterial mechanism is unknown. In this study, phenotypic experiments and RNA sequencing were used to explore the antibacterial mechanism. The minimum inhibitory concentration of EGCG on C. jejuni was 32µg/mL. EGCG-treated was able to increase intracellular reactive oxygen species levels and decline bacterial motility. The morphology and cell membrane of C. jejuni after EGCG treatment were observed collapsed, broken, and agglomerated by field emission scanning electron microscopy and fluorescent microscopy. The RNA-seq analysis presents that there are 36 and 72 differential expressed genes after C. jejuni was treated by EGCG with the concentration of 16 and 32µg/mL, respectively. EGCG-treated increased the thioredoxin expression, which was a critical protein to resist oxidative stress. Moreover, downregulation of the flgH and flgM gene in flagellin biosynthesis of C. jejuni was able to impair the flagella, reducing cell motility and virulence. The primary antibacterial mechanism revealed by RNA-seq is that EGCG with iron-chelating activity competes with C. jejuni for iron, causing iron deficiency in C. jejuni, which potentially impacts the survival and virulence of C. jejuni. The results suggested a new direction for exploring the activity of EGCG against C. jejuni in the food industry. PRACTICAL APPLICATION: A deeper understanding of the antibacterial mechanism of EGCG against C. jejuni was more beneficial in improving the food safety, eliminating concerns about human health caused by C. jejuni in future food, and promoting the natural antibacterial agent EGCG application in the food industry.

Protective effects of EGCG on acrolein-induced Caenorhabditis elegans and its mechanism of life extension.

In this study, it was found that epigallocatechin-3-gallate (EGCG) could extend the lifespan of Caenorhabditis elegans (C. elegans) induced by 100 μM acrolein (ACR) at all test concentrations (300, 400, 500, 600, and 700 μM). Notably, 500 μM EGCG exhibited the most significant mean lifespan extension, increasing it by approximately 32.5%. Furthermore, 500 μM EGCG effectively reduced elevated levels of reactive oxygen species (ROS) and lipofuscin production caused by acrolein. It also bolstered the activity of antioxidant enzymes and mitigated malondialdehyde (MDA) levels compared to the ACR-only group. These effects appeared independent of dietary restrictions. Additionally, qPCR results revealed different changes in the transcription levels of 11 genes associated with antioxidative and anti-aging functions following EGCG treatment. At the expression level, GST-4::GFP, SOD-3::GFP and HSP-16.2::GFP exhibited an initial increase with ACR treatment followed by a decrease with EGCG treatment, while the expression pattern of these three GFPs remained consistent with the enzyme activity and transcription regulation level. EGCG treatment also reduced the nuclear localization of SKN-1 and DAF-16 in the MAPK and IIS pathways that were enhanced by ACR. Moreover, the longevity-promoting effects of EGCG were diminished or absent in 13 longevity gene-deletion mutants. In conclusion, EGCG demonstrates protective effects on ACR-induced C. elegans, with the IIS and MAPK pathways playing a critical role in enhancing resilience to ACR.

Autologous transplantation of green tea epigallocatechin-3-gallate pretreated adipose-derived stem cells increases cardiac regenerative capability through C-X-C motif chemokine receptor 4 expression in the treatment of rats with diabetic cardiomyopathy.

Cardiomyopathy is one of complications related to diabetes. Stem cell transplantation shows potential in diabetic cardiomyopathy treatment. Epigallocatechin-3-gallate (EGCG) is one of the major components found in green tea. Although stem cell transplantation and green tea EGCG supplementation show therapeutic effects on cardiomyopathy, the detailed cellular mechanisms in stem cell transplantation coupled with EGCG treatment remain unclear. This study investigates whether adipose-derived stem cells (ADSC) pretreated with EGCG show better protective effect on diabetic cardiomyopathy than ADSC without EGCG pretreatment. A cell model indicated that ADSC pretreated with EGCG increased cell functions including colony formation, migration and survival markers. All of these functions are blocked by small interfering C-X-C motif chemokine receptor 4 (siCXCR4) administration. These findings suggest that ADSC pretreatment with EGCG increases cell functions through CXCR4 expression. A diabetic animal model was designed to verify the above findings, including Sham, DM (diabetic rats), DM+ADSC (DM rats receiving autologous transplantation of ADSC) and DM+E-ADSC (DM rats receiving EGCG pretreated ADSC). Compared to the Sham, we found that all of pathophysiological signalings were activated in the DM group, including functional changes (decrease in ejection fraction and fractional shortening), structural changes (disarray and fibrosis) and molecular changes (increases in apoptotic, fibrotic, hypertrophic markers and decreases in survival and longevity markers). E-ADSC (DM+E-ADSC) transplantation shows significant improvement in the above pathophysiological signalings greater than ADSC (DM+ADSC). Therefore, ADSC pretreated with EGCG may contribute to clinical applications for diabetic patients with cardiomyopathy.

Evaluation of the differential gene expression of the impact of epicatechin-3-gallate (EGCG) on antioxidant enzymes in mice at risk for cardiovascular disease

The polyphenol epigallocatechin-3-gallate (EGCG), which is present in green tea, has been demonstrated to possess antioxidant qualities, possible advantages for cardiovascular health, and therapeutic effects in non-alcoholic fatty liver disease (NAFLD), a common ailment that impairs liver function. This work looked at the effects of EGCG on the differential gene expression levels of the superoxide dismutase 2(SOD2), Glutathione peroxidase-1 (Gpx1), Catalase (CAT), and Thioredoxin Reductase (TrxR1) genes coding for antioxidant defense enzymes to determine whether EGCG could enhance antioxidant defense capacity in mice at risk of cardiovascular disease caused by a high-fat diet and sedentary lifestyle. It was shown that liver tissue samples from male mice fed a high-fat diet (HFD) and two control diets (CD) with or without EGCG supplementation showed distinct expression patterns for the genes Sod2, Gpx1, Catalase, and other transcripts. For this investigation of differential gene expression levels, male mice with sedentary lifestyles and two different control groups that underwent physical activity with or without EGCG treatment were also utilized. GraphPad Prism version 6 was used to conduct Tukey-Kramer multiple comparison tests between the treatment and control groups. For the results, p 0.05 was chosen as the significant level. The study results show that EGCG increases the enzyme activities of Sod2, Gpx1, CAT, and TrxR1 which are related to antioxidant defense differential gene expression. The results of this study demonstrated that cycle threshold (CT) values before EGCG supplementation were greater than CT values after EGCG supplementation (p-value = 0.424 versus p-value = 0.2541 for diets and p-value = 0.5547 versus p-value = 0.5149 for physical exercise), suggesting that EGCG enhanced the differently expressed genes.

Epigallocatechin gallate prevents cardiomyocytes from pyroptosis through lncRNA MEG3/TAF15/AIM2 axis in myocardial infarction

Background( −)-Epigallocatechin-3-gallate (EGCG), a bioactive polyphenol isolated from green tea, has recently garnered attention for its potential protective role against acute myocardial infarction (MI) via inhibiting inflammation. Herein, we tested whether EGCG participates in modulating cardiac ischemia reperfusion-induced injury and elucidate its potential mechanisms.MethodsTo induce MI in mice, we employed coronary artery ligation, while cell models utilized oxygen glucose deprivation/re-oxygenation (OGD/R)-treated HL-1 cells. TTC, HE and Massion staining evaluated the pathological changes of heart tissues. Besides, RNA-pull down and RIP assays analyzed the interactions of MEG3/TAF15 and AIM2 mRNA/TAF15. FISH associated with immunofiuorescence (IF) double staining was conducted to measure the co-localization of MEG3 and TAF15.ResultsIn vitro and in vivo evidence supported that EGCG treatment improved cardiomyocytes viability while inhibiting the expressions of AIM2, C-caspase-1, ASC, GSDMD-N, IL-18 and IL-1β. Knockdown of MEG3 intensified EGCG's therapeutic effects both in vitro and in vivo. LncRNA MEG3 and AIM2 mRNA interacted with TAF15, and MEG3, in turn, promoted the stability of AIM2 mRNA through regulating TAF15. Overexpression of TAF15 reversed the promoting effect of EGCG and MEG3 knockdown on cell viability, and the inhibiting effect on cell pyroptosis.ConclusionEGCG protected cardiomyocytes from pyroptosis by the MEG3/TAF15/AIM2 axis, indicating EGCG as a potential novel therapeutic strategy for managing MI.

#236 : Alleviating Effects of EGCG on Ovarian Hyperstimulation Syndrome and the Potential Modulating Mechanism

Background and Aims: Ovarian hyperstimulation syndrome (OHSS) is one of the most severe complications of COH during IVF treatment. Increased capillary permeability is a hallmark of the pathophysiology of OHSS, vascular endothelial growth factor (VEGF) is an important mediator in OHSS, and studies have established a correlation between serum VEGF levels and the severity of the OHSS. (-)-epigallocatechin-3-gallate (EGCG), the most prevalent and biologically active polyphenolic catechin in green tea, has been reported to produce a number of beneficial effects on humans. Numerous studies have shown that in many pathological processes, EGCG could inhibit VEGF and its receptor expression and have an angiogenesis effect. Herein, EGCG might have a therapeutic effect on OHSS. Methods: We investigated the role of EGCG in OHSS both in vitro and in vivo. Primary human granulosa-lutein (hGL) cells and a human granulosa-like tumor (KGN) cell line were cultured and treated for 24 hours with various concentrations of EGCG. In SD rats, an animal OHSS model was established by injecting pregnant mare serum gonadotropin (PMSG) and randomly assigning them to receive vehicle only or EGCG for three days. For comparison, all experiments were repeated 3-8 times. The effect of EGCG on KGN and hGL cells was determined by MTT assay. The body weight of rats was measured every day, and the ovary size and weight were measured after removal. Evans-blue was used to determine permeability. ELISA was used to measure serum estrogen and VEGF levels in rats. RNA and protein expressions of VEGF, VEGFR-2, TGF-[Formula: see text]1, and T[Formula: see text]R II were detected by qPCR and Western-blotting and immunostaining in vitro and in vivo experiments. Results: Our research found that giving rats EGCG prevented the development of OHSS, as evidenced by histological examination, ovarian weight, and morphology. When compared to the OHSS group, the EGCG treatment group had significantly lower ovary weight (147.9 vs 206.5 mg) (Fig. 1). Furthermore, when compared to OHSS rats, EGCG-treated rats have lower ovarian VEGF expression as measured by IHC and RT-qPCR. VEGF and E2 protein levels in the serum of the EGCG treatment group are significantly lower. EGCG exerted inhibitory effects on cell growth only in high dose (50 uM) and longtime (48 h) treatment in KGN and hGL cells. In KGN cells and hGL cells, EGCG significantly reduces the expression of VEGF and TGF-[Formula: see text] at the RNA and protein levels. Furthermore, EGCG inhibits TGF-[Formula: see text]1-induced VEGF production and secretion in KGN cells by suppressing TGF-[Formula: see text] expression and its traditional Smad signaling pathway. EGCG also downregulates VEGF expression through the 67-kDa laminin receptor-mediated PKA-CREB pathway (Fig. 2). Conclusions: EGCG inhibited VEGF via the TGF-[Formula: see text]1 classical-SMAD pathway and the 67LR-mediated CREB pathway, reducing ovarian inflammation and slowing the progression of OHSS in a rat model.

Epigallocatechin-3-Gallate (EGCG) Ameliorates Ineffective Hematopoiesis of Myelodysplasia Syndrome (MDS)

Epigallocatechin-3-gallate (EGCG) is a gallate ester obtained by condensation of gallic acid with the (3R)-hydroxy group of (-)-epigallocatechin, extracted from green tea, exhibiting beneficial effects as an apoptosis and cell differentiation inducer helping counteract uncontrolled proliferation and impaired differentiation characteristic of leukemia and myelodysplastic syndrome. Clinical trials in patients with chronic lymphoid leukemia, low grade B-lymphomas and acute myeloid leukemia with myelodysplasia related changes were carried out showing positive results. This study aimed to evaluate the in vivo effect of EGCG in a mice model of myelodysplastic syndrome (NHD13 mice). B6.SJL-PtprcaPep3b/BoyJ mice (PepBoy) received 9,5Gy irradiation followed by transplantation of bone marrow cells from NUP98-HOXD13 mice by i.v. caudal vein injection; disease establishment was confirmed at day 15 by blood cytopenia. To assess the EGCG effects on MDS, 10-week-old female NUP98-HOXD13 mice (NHD13 +) and their littermate WT mice (NHD13 -) were treated for 4 weeks with EGCG (50mg/Kg/day 5x/week i.p.) or vehicle. The animals were then sacrificed, and bone marrow and spleen were obtained for flow cytometry and histology analyses. Automated hematological counts and clinical biochemistry parameter analysis were done. After signing the written informed consent, a 71-year-old man diagnosed with high-risk MDS, with 9% blasts in the bone marrow, underwent a daily oral 800mg EGCG treatment. This study was approved by the Ethical Committee of University of Campinas and by the National Research Ethics Committee ( CAAE: 40656720.5.0000.5404). During this period, the patient underwent weekly clinical assessments and laboratory studies to monitor any potential toxicity. Peripheral blood samples were obtained before and after treatment to observe any alteration in cell counts and immune cell composition. Before treatment, NDH13 + exhibited a reduction in number of leukocytes, platelets, and hemoglobin levels, in accordance with the literature. EGCG treatment ameliorated hematological parameters, showed by increased leukocyte numbers (monocytes and neutrophils) and platelets with no signals of liver and kidney toxicity detected by histology and serum biochemistry. Untreated mice showed increased osteoprogenitor, osteoblast and endothelial cells in the bone marrow, corroborating the literature. EGCG treatment did not alter the frequency of these cells, HSC or immature cells (CD34 + or CD117 +). However, EGCG induced extramedullary hematopoiesis in spleen and no changes in the percentage/frequency of Foxp3 + regulatory T cells (CD4 +CD25 + and/or CD4 +FOXP3 +). Additionally, the patient treated by ECGC for one month exhibited reduction of regulatory T cells CD4 +CD25 + and CD4 +FOXP3 +, and increased CD8 + T cells (CD3 +CD8 +) and natural killer cells (CD16 +CD56 +) accompanied by increased mature leukocytes (monocytes and neutrophils), with no changes in hemoglobin and platelet number. Our initial findings indicate that EGCG induces improved hematological parameters in MDS and might shift immune cells to a more cytotoxic phenotype. The extramedullary hematopoiesis observed in mice may be due to reduction of CXCR4 in bone marrow cells, as previously described by our group. In summary, EGCG might be a promising adjuvant in the treatment of MDS. Further research and clinical studies are warranted to validate and fully explore EGCG therapeutic benefits. Fig1a EGCG ameliorates NHD13 and transplanted mice hematological parameters. At the end of the EGCG treatment (50mg/kg/day i.p) or vehicle (Ctrl), NHD13 + and transplanted (PepBoy) mice were bled from the retro-orbital plexus. EGCG induced an increased the number of leukocytes ( A), monocytes ( B), neutrophils ( C) and the number of platelets ( D) using the CELL-DYN Emerald Hematology System counter. EGCG represented by the green column, and the vehicle by the gray color. Statistical significance ( Mann-Whitney test) is indicated; n=6 per group. Fig1b. EGCG improved the immune system of HR-SMD patient. A 71-years-old man with HR-SMD received EGCG treatment (800 mg/Kg/day) for 30 days. Peripheral blood counts were evaluated at day 0 and day 30. EGCG ameliorated hematological parameters - increased mature leukocytes (A) - monocytes (B) and neutrophils (C), with no changes in hemoglobin (D) and platelets

Dietary Epigallocatechin-3-Gallate (EGCG) Improves Nonspecific Immune Response of Chinese Rice Field Eel (Monopterus albus).

Epigallocatechin-3-gallate (EGCG) has been recognized as a potential additive for aquafeeds due to its beneficial biological functions. In order to evaluate the potential application of EGCG in Chinese rice field eel (Monopterus albus), six isonitrogenous and isolipidic diets containing 0, 25, 50, 100, 200, and 400 mg/kg EGCG were formulated and were fed to Monopterus albus (M. albus) for 9 weeks. The results showed that M. albus fed diets containing 0 and 100 mg/kg EGCG presented higher weight again and specific growth rate than the other groups. Fish fed with 25, 50, and 400 mg/kg EGCG displayed lower whole-body lipid content. Serum aspartate aminotransferase (AST) concentration significantly decreased in EGCG treated groups with the exception of 100 mg/kg group. Hepatic catalase (CAT) activity and glutathione (GSH) concentration decreased as EGCG level increased while malondialdehyde (MDA) concentration showed an opposite trend. EGCG supplementation resulted in a promoted lysozyme (LZM) activity and immunoglobulin M (IgM) level in the liver of M. albus. Furthermore, transcription of three immune related genes including major histocompatibility complex (mhc-2α), hepcidin, and interleukin-8 (il-8) mRNAs was upregulated by EGCG treatment; while transcription of interleukin-6 (il-6) and nuclear factor kappa-B (nf-kb) genes was downregulated. Results also showed a linear relation between EGCG inclusion level and parameters of AST, CAT, GSH, MDA, LZM, IgM, and immune-related genes transcriptions. In summary, it could be suggested that EGCG supplementation enhanced the nonspecific immune response of the Chinese rice field eel. Based on the broken-line regression analysis of IgM, the optimal dietary EGCG supplementation for M. albus was estimated to be 109.81 mg/kg.

Epigallocatechin gallate delays age-related cataract development via the RASSF2/AKT pathway

Age-related cataract (ARC) is a common eye disease, the main cause of which is oxidative stress-mediated apoptosis of lens epithelial cells (LECs). Epigallocatechin gallate (EGCG) is the most potent antioxidant in green tea. Our results demonstrated that EGCG could effectively reduce apoptosis of LECs and retard lens clouding in aged mice. By comparing transcriptome sequencing results of three groups of mice (young control, untreated aged, and EGCG-treated) and screening using GO and KEGG analyses, we selected RASSF2 as the effector gene of EGCG for mechanistic exploration. We verified that the differential expression of RASSF2 was associated with the occurrence of ARC in clinical samples and mouse tissues by immunohistochemistry and western blotting, respectively. We showed that high RASSF2 expression plays a crucial role in the oxidative induction of apoptosis in LECs, as revealed by overexpression and interference experiments. Further studies showed that RASSF2 mediates the inhibitory effect of EGCG on apoptosis and ARCogenesis in LECs by regulating AKT (Ser473) phosphorylation. In this study, we found for the first time the retarding effect of EGCG on lens clouding in mice and revealed the mechanism of action of RASSF2/AKT in it, which provides a theoretical basis for the targeted treatment of EGCG.

Protective effects of epigallocatechin-3-gallate counteracting the chronic hypobaric hypoxia-induced myocardial injury in plain-grown rats at high altitude

Exposure to hypobaric hypoxia (HH) environment causes stress to the body, especially the oxygen-consuming organs. Chronic HH conditions have adverse effects on the myocardium. Thus, we conducted this experiment and aim to evaluate such adverse effects and explore the therapeutic role of epigallocatechin-3-gallate (EGCG) in rats’ heart under chronic HH conditions. For that purpose, we transported rats from plain to a real HH environment at high altitude for establishing the HH model. At high altitude, animals were treated with EGCG while the salidroside was used as the positive control. General physiological data were collected, and routine blood test results were analyzed. Cardiac magnetic resonance (CMR) was examined to assess the structural and functional changes of the heart. Serum levels of cardiac enzymes and pro-inflammatory cytokines were examined. Oxidative markers in the left ventricle (LV) were detected. Additionally, ultrastructural and histopathological changes and apoptosis of the LV were assessed. Furthermore, the antioxidant stress-relevant proteins nuclear factor E2-related factor 2 (Nrf2) and the heme oxygenase-1 (HO-1) were detected. The experiment revealed that EGCG treatment decreased HH-induced elevation of cardiac enzymes and relieved mitochondrial damage of the LV. Notably, EGCG treatment significantly alleviated oxidative stress in the LV and inflammatory response in the blood. Western blot confirmed that EGCG significantly upregulated Nrf2 and HO-1. Therefore, EGCG may be considered a promising natural compound for treating the HH-induced myocardial injuries.

Green tea polyphenol EGCg induces cell fusion via reactive oxygen species

BackgroundOsteoclasts are multinucleated cells formed by macrophage cell fusion that are responsible for bone resorption. Previously, we found that treating osteoclastic progenitor cells with (−)-epigallocatechin gallate (EGCg) increased cell fusion. In this study, we aimed to identify factors involved in the cell fusion induced by EGCg. MethodsWe hypothesized that EGCg-induced oxidative stress might be involved in cell fusion, and used macrophage cell line RAW264.7 cells. We evaluated cell fusion activity after adding the antioxidants N-acetyl-l-cysteine (NAC) or catalase in addition to EGCg. The mRNA expressions of genes related to cell fusion and bone resorption were quantified by real-time PCR. Finally, we added hydrogen peroxide and examined its effects on cell fusion and TRAP activity. ResultsEGCg-induced cell fusion was strongly inhibited by the addition of NAC in a dose-dependent manner (EGCg with 5 mM NAC; decreased to 1.5%; p < 0.05), while the inhibitory effect of catalase was limited (EGCg with 500 U/mL catalase; decreased to 27.7%; p < 0.05). DC-STAMP expression was significantly upregulated by EGCg compared with the untreated group, and the upregulation was significantly suppressed by 5 mM NAC. Conversely, Nfatc1 and TRAP expression were not upregulated by EGCg. These results suggest that EGCg induces DC-STAMP expression via reactive oxygen species production, which regulates cell fusion but does not affect the osteoclastic pathway. Although treatment with hydrogen peroxide promoted the formation of multinucleated cells, no increase in TRAP activity was observed, which was similar to EGCg treatment. ConclusionsThis study suggests that the increased cell fusion by EGCg may be induced by oxidative stress due to reactive oxygen species production.