Epigallocatechin-3-gallate Group Research Articles

Evaluation of Endometrial Angiogenesis in Mice Uterus Before Implantation in Natural Cycles Followed by Use of Human Menopausal Gonadotropin - Human Chorionic Gonadotropin Drugs and Epigallocatechin Gallate.

Background:Angiogenesis plays a major role in endometrial receptivity and thickening of the endometrium immediately before implantation. The aim of the present work was to evaluate the antiangiogenic properties of epigallocatechin-3-gallate (EGCG) from green tea in angiogenesis of endometrium.Materials and Methods:In this study, forty adult female NMARI mice randomly divided into four groups. Control group received vehicle; human menopausal gonadotropin/human chorionic gonadotropin (HMG/HCG) group received 7.5 IU HMG intraperitoneal (IP) and 48 h later 7.5 IU HCG was injected (IP) for ovarian stimulation; HMG/HCG + EGCG group received HMG and HCG in the same manner as the previous group and also received 5 mg/kg EGCG at 0, 24, 48, and 72 h after injection of HMG; and the group EGCG received 5 mg/kg EGCG. A male mouse was kept with two female animals in the same cage for mating. Mice were dissected 96 h after administration of HMG (immediately before implantation) and tissue processing was carried out for the uterine specimens. CD31-positive cells were counted by use of histological and immunohistochemical methods.Results:Angiogenesis in EGCG-treated group was less than that of control and gonadotropin group (P < 0.05). The number of endothelial cells was counted by CD31 marker under a light microscope and showed significant differences between all groups (P < 0.05).Conclusion:EGCG significantly inhibited the angiogenesis in endometrium (in natural cycles) through antiangiogenic effects.

In vitro Effects of Epigallocatechin Gallate on Sister Chromatid Exchange in the Lymphocytes Exposed to Glyphosate

Purpose: Green tea is known as a potent anti-oxidant, anti-carcinogen, and genetic protector. Glyphosate (N-phosphonomethyl glycine) is a widely used non-selective herbicide that causes DNA damage. The present study was conducted to investigate the protective effects of green tea in human blood lymphocytes exposed to glyphosate using the Sister Chromatid Exchange (SCE) frequency method. Methods: Peripheral blood was obtained from 10 volunteers and cultured through four different conditions. Four groups were divided into control, glyphosate only (300 ng/mL), glyphosate and low ($20{mu}m$) concentrations of epigallocatechin gallate (EGCG) and glyphosate and high ($100{mu}m$) concentrations of EGCG. Results: The glyphosate exposed groups had a higher mean SCE frequency ($10.33{pm}2.50$) than the control group ($6.38{pm}2.28$, p&lt;0.001). The low concentrations of EGCG groups had a lower mean SCE frequency ($9.91{pm}1.93$) than the glyphosate-only group, although this difference was not significant (p=0.219). However, the high concentration group ($9.49{pm}1.85$) had a significantly lower SCE frequency than the glyphosate-only group (p=0.001). Conclusion: EGCG has a gene protective effect in human lymphocytes exposed to the genotoxicity of glyphosate in the case of high concentrations.

Effect of epigallocatechin-3-gallate on the proliferation and osteogenesis of human periodontal ligament cells

Objective: To evaluate the effect of epigallocatechin-3-gallate (EGCG) treatment on the proliferation and osteogenic differentiation of human periodontal ligament cell (hPDLC) and to explore the potential role of EGCG in promoting periodontal hard tissue regeneration. Methods: The hPDLC was isolated from periodontal ligament tissue obtained from freshly extracted human teeth. The effect of treatments with various concentrations of EGCG (0 μmol/L, 2 μmol/L, 4 μmol/L, 6 μmol/L, 8 μmol/L and 10 μmol/L) on cell proliferations were determined by cell counting kits (CCK) after 24-, 48- and 72-hour-incubations, respectively. Osteogenic differentiation abilities of hPDLCs were assessed by using alkaline phosphatase (ALP) activity tests after 7- and 14-day-incubations, respectively. The mineralized nodules were quantitatively examined and analyzed by using alizarin red staining after 21-day-incubation. The real-time PCR (RT-PCR) assays were conducted fordetecting the expressions of Runt related transcription factor-2 (Runx2), ALP and collagen type Ⅰ (COL Ⅰ) after 7-day-incubation. Results: Treatment with 4 μmol/L EGCG increased hDPLC proliferation at 24 h, while 8 μmol/L or 10 μmol/L EGCG treatment groups showed inhibiting effects at 24 h and 72 h, respectively. Findings of alizarin redstaining showed orange to red colored extracellular mineralized nodules in all groups. The the A values of 2, 4, 6, 8, 10 μmol/L EGCG groups were 0.119±0.001, 0.167±0.003, 0.173±0.003, 0.110±0.001 and 0.083±0.003, respectively. A values of 2-8 μmol/L EGCG groups were significantly higher than that of the control group, however there was no significant difference of the A values between10 μmol/L EGCG group and the control group (0.077±0.001). Treatments with 2-10 μmol/L EGCG could significantly increase the mRNA expressions of COL Ⅰ and ALP with the highest values in 4-6 μmol/L EGCG treatment groups. Although treatments with 4 and 6 μmol/L EGCG both could increase the mRNA expressions of Runx2, the result in 4 μmol/L group was much better than that of 6 μmol/L group. Conclusions: Treatment of 4 μmol/L EGCG could promote hPDLC proliferation at early stageand treatments with 4-6 μmol/L EGCG could significantly promote the osteogenesis of hPDLCs which might play a promising role in periodontal hard tissue regeneration.

Resveratrol and Epigallocatechin-3-gallate addition to thawed boar sperm improves in vitro fertilization

Thawing is one of the most delicate process after semen cryopreservation as spermatozoa pass from a dormant metabolic stage to a sudden awakening in cellular metabolism. The rapid oxygen utilization leads to an overproduction of reactive oxygen species that can damage sperm cells, thus causing a significant decrease of fertilizing potential of frozen-thawed spermatozoa. Resveratrol (Res) is a natural grape-derived phytoalexin and Epigallocatechin-3-gallate (EGCG) is the major polyphenol in green tea (Camellia sinensis); both molecules are known to possess high levels of antioxidant activity. The objective of the present study was to assess the effect of different concentrations of Res (0.5, 1 or 2 mM; Experiment 1) or EGCG (25, 50 or 100 μM; Experiment 2) supplementation to thawing boar semen extender on sperm quality parameters (viability and acrosome integrity) and in vitro fertilization (IVF). Semen after thawing and dilution with three volumes of Beltsville Thawing Solution (BTS), was immediately divided in control group without antioxidants addition (CTR) and either Res or EGCG groups. Sperm viability and acrosome integrity were evaluated in CTR, Res or EGCG groups after 1 h of incubation at 37 °C. The addition of different doses of Res or EGCG to thawing extender for 1 h did not induce any effect on boar sperm viability and acrosome integrity. However, both Res and EGCG treated samples exhibited a significantly higher penetration rate compared with CTR when used for IVF. In particular the treatment with all the EGCG concentrations increased the penetration rate (P < 0.01) while only Res 2 mM induced a significant increase of this parameter (P < 0.01). In addition, EGCG 25 and 50 μM supplementation significantly increased total fertilization efficiency as compared to control (EGCG 25 μM: 40.3 ± 8.2 vs 26.8 ± 9.5, P < 0.05; EGCG 50 μM: 40.4 ± 7.8 vs 26.8 ± 9.5, P < 0.01). The same effect was observed with Res 2 mM (51.0 ± 7.6 vs 29.6 ± 11.3, P < 0.01). In conclusion, our results indicate that the addition of different doses of the two antioxidants to thawed spermatozoa for one hour, even if does not exert any effect on sperm viability and acrosome integrity, efficiently improves in vitro penetration rate. Moreover, both molecules (EGCG 25 and 50 μM and Res 2 mM) significantly increases the total efficiency of fertilization.

Epigallocatechin gallate inhibits the proliferation and apoptosis of keratinocytes induced by interleukin-17

Objective To evaluate the protective effect of epigallocatechin gallate (EGCG) against interleukin (IL) -17-induced injury to keratinocytes, and to explore its mechanism. Methods Some cultured HaCaT cells were divided into 3 groups to be treated with IL-17 alone at concentrations of 50, 70, 90 μg/L, respectively, with those receiving no treatment as the blank control group. Some HaCaT cells were divided into 5 groups: IL-17 group treated with 90 μg/L IL-17 alone, IL-17+EGCG group treated with 90 μg/L IL-17 and 60 μmol/L EGCG, IL-17+SP600125 group treated with 90 μg/L IL-17 and SP600125 (a JAK signaling pathway inhibitor) , IL-17+ EGCG+anisomycin group treated with 90 μg/L IL-17, 60 μmol/L EGCG and anisomycin (a Janus kinase signaling pathway activator) , and blank control group receiving no treatment. After different durations of treatment, CCK-8 assay was performed to evaluate cellular proliferative activity, flow cytometry to detect cell apoptosis, enzyme-linked immunosorbent assay (ELISA) to measure expression levels of IL-6, IL-23 and IL-8, and Western-blot analysis to determine protein expressions of c-Jun N-terminal kinase (JNK) and phosphorylated JNK (P-JNK) . Results IL-17 promoted cellular proliferation of HaCaT cells, and the proliferation rate, which was correlated with the concentration of IL-17, reached the maximum in the 90-μg/L IL-17 group (P < 0.05) . EGCG at 60 μmol/L significantly inhibited cellular proliferation of, promoted apoptosis in, and reduced IL-6, IL-23 and IL-8 expressions in, HaCaT cells induced by 90 μg/L IL-17 (all P < 0.05) . Compared with the IL-17 group, the IL-17+EGCG group and IL-17+SP600125 group both showed significantly decreased P-JNK expression, cell proliferation rate and IL-6, IL-23 and IL-8 expression levels (all P < 0.05) . However, compared with the IL-17+EGCG group, the IL-17+EGCG+anisomycin group showed significantly increased protein expression of P-JNK, cell proliferation rate and IL-6, IL-23 and IL-8 expression levels (all P < 0.05) . Conclusion EGCG protected against IL-17-induced injury to HaCaT cells, such as abnormal cell proliferation, apoptosis and inflammatory response, likely by inhibiting the JNK signaling pathway. Key words: Keratinocytes; Catechin; Interleukin-17; Cell proliferation; Apoptosis; Epigallo-catechin gallate

Green tea (-)-epigallocatechin-3-gallate counteracts daytime overeating induced by high-fat diet in mice.

High-fat diet (HFD) induces overeating and obesity. Green tea (-)-epigallocatechin-3-gallate (EGCG) reduces HFD-induced body weight and body fat gain mainly through increased lipid metabolism and fat oxidation. However, little is known about its effect on HFD-induced alterations in feeding behavior. Three diet groups of wildtype C57B/6j male mice at 5 months old were fed on normal chow diet, 1 week of HFD (60% of energy) and 3 months of HFD (diet-induced obesity (DIO)) prior to EGCG supplement in respective diet. EGCG had no effect on feeding behavior in normal chow diet group. Increased daytime feeding induced by HFD was selectively corrected by EGCG treatment in HFD groups, including reversed food intake, feeding frequency and meal size in HFD + EGCG group, and reduced food intake and feeding frequency in DIO + EGCG group. Moreover, EGCG treatment altered diurnally oscillating expression pattern of key appetite-regulating genes, including AGRP, POMC, and CART, and key circadian genes Clock and Bmal1 in hypothalamus of DIO mice, indicating its central effect on feeding regulation. Our study demonstrates that EGCG supplement specifically counteracts daytime overeating induced by HFD in mice, suggesting its central role in regulating feeding behavior and energy homeostasis.

Prevention of abdominal aortic aneurysm progression by oral administration of green tea polyphenol in a rat model

ObjectiveInflammation-mediated elastin destruction in the aortic medial layer is related to progression of abdominal aortic aneurysm (AAA). Epigallocatechin-3-gallate (EGCG), a major component of green tea polyphenols, reportedly increases elastin synthesis in vitro and may possess anti-inflammatory effects. We used a rat model to investigate whether EGCG could prevent AAA progression. MethodsAAA was induced with administration of intraluminal elastase and extraluminal CaCl2 in male rats. Rats were randomly divided into a control group (n = 30) and an EGCG group (n = 30). In the EGCG group, an EGCG solution (20 mg/d) was administered orally to each rat from 2 weeks before AAA induction and continued 4 weeks beyond induction. ResultsThe abdominal aortic diameter was significantly smaller in the EGCG group than in the control group on day 28 (2.9 ± 0.2 vs 2.3 ± 0.1 mm; P < .0001). The medial layer wall thickness and elastin content were significantly greater in the EGCG group than in the control group on day 28 (68.4 ± 13.6 vs 46.7 ± 13.4 μm [P < .001] and 20.3 ± 4.6 vs 9.5 ± 3.6% [P < .0001], respectively). Gene expression levels of tropoelastin and lysyl oxidase were significantly higher in the EGCG group immediately before AAA induction, indicating promoted elastoregeneration by EGCG administration (tropoelastin: 0.59 ± 0.36 control vs 1.24 ± 0.36 EGCG [P < .05], lysyl oxidase: 0.77 ± 0.45 control vs 1.34 ± 0.4 EGCG [P < .05]) (fold increase). Gene expression levels of inflammatory cytokines, including tumor necrosis factor-α and interleukin-1β, were significantly downregulated in the EGCG group (1.82 ± 0.71 vs 0.97 ± 0.59 [P < .05] and 3.91 ± 3.24 vs 0.89 ± 0.59 [P < .05], respectively). On day 7, gene expression levels and gelatinolytic activity of matrix metalloproteinase 9 were significantly lower in the EGCG group (1.41 ± 0.86 vs 0.51 ± 0.42 [P < .05] and 1.00 ± 0.17 vs 0.29 ± 0.12 [P < .0001], respectively), whereas gene expression levels of tissue inhibitors of metalloproteinase-1 were significantly higher in the EGCG group (0.96 ± 0.11 vs 1.14 ± 0.09; P < .05). ConclusionsEGCG attenuated AAA progression in a rat model by preserving the aortic thickness and elastin content of the medial layer through regeneration of elastin, as mediated by anti-inflammatory effects, and subsequent reduction of matrix metalloproteinase activity.

Safety and efficacy of cognitive training plus epigallocatechin-3-gallate in young adults with Down's syndrome (TESDAD): a double-blind, randomised, placebo-controlled, phase 2 trial

Early cognitive intervention is the only routine therapeutic approach used for amelioration of intellectual deficits in individuals with Down's syndrome, but its effects are limited. We hypothesised that administration of a green tea extract containing epigallocatechin-3-gallate (EGCG) would improve the effects of non-pharmacological cognitive rehabilitation in young adults with Down's syndrome. We enrolled adults (aged 16-34 years) with Down's syndrome from outpatient settings in Catalonia, Spain, with any of the Down's syndrome genetic variations (trisomy 21, partial trisomy, mosaic, or translocation) in a double-blind, placebo-controlled, phase 2, single centre trial (TESDAD). Participants were randomly assigned at the IMIM-Hospital del Mar Medical Research Institute to receive EGCG (9 mg/kg per day) or placebo and cognitive training for 12 months. We followed up participants for 6 months after treatment discontinuation. We randomly assigned participants using random-number tables and balanced allocation by sex and intellectual quotient. Participants, families, and researchers assessing the participants were masked to treatment allocation. The primary endpoint was cognitive improvement assessed by neuropsychologists with a battery of cognitive tests for episodic memory, executive function, and functional measurements. Analysis was on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT01699711. The study was done between June 5, 2012, and June 6, 2014. 84 of 87 participants with Down's syndrome were included in the intention-to-treat analysis at 12 months (43 in the EGCG and cognitive training group and 41 in the placebo and cognitive training group). Differences between the groups were not significant on 13 of 15 tests in the TESDAD battery and eight of nine adaptive skills in the Adaptive Behavior Assessment System II (ABAS-II). At 12 months, participants treated with EGCG and cognitive training had significantly higher scores in visual recognition memory (Pattern Recognition Memory test immediate recall, adjusted mean difference: 6·23 percentage points [95% CI 0·31 to 12·14], p=0·039; d 0·4 [0·05 to 0·84]), inhibitory control (Cats and Dogs total score, adjusted mean difference: 0·48 [0·02 to 0·93], p=0·041; d 0·28 [0·19 to 0·74]; Cats and Dogs total response time, adjusted mean difference: -4·58 s [-8·54 to -0·62], p=0·024; d -0·27 [-0·72 to -0·20]), and adaptive behaviour (ABAS-II functional academics score, adjusted mean difference: 5·49 [2·13 to 8·86], p=0·002; d 0·39 [-0·06 to 0·84]). No differences were noted in adverse effects between the two treatment groups. EGCG and cognitive training for 12 months was significantly more effective than placebo and cognitive training at improving visual recognition memory, inhibitory control, and adaptive behaviour. Phase 3 trials with a larger population of individuals with Down's syndrome will be needed to assess and confirm the long-term efficacy of EGCG and cognitive training. Jérôme Lejeune Foundation, Instituto de Salud Carlos III FEDER, MINECO, Generalitat de Catalunya.

Radioprotective Effect of Epigallocatechin-3-Gallate on Salivary Gland Dysfunction After Radioiodine Ablation in a Murine Model.

Objectives.Radioiodine (RI) therapy is known to subject cellular components of salivary glands (SG) to oxidative stress leading to SG dysfunction. However, the protective effects of antioxidants on RI-induced SG damage have not been well investigated. The authors investigated the morphometric and functional effects of epigallocatechin-3-gallate (EGCG) administered prior to RI therapy and compared this with the effects of amifostine (a well-known antioxidant) in a murine model of RI sialadenitis.Methods.Four-week-old female C57BL/6 mice (n=48) were divided into four groups; a normal control group, a RI-treated group (0.01 mCi/g mouse, orally), an EGCG and RI-treated group, and an amifostine and RI-treated group. Animals in these groups were divided into 3 subgroups and euthanized at 15, 30, and 90 days post-RI treatment. Salivary flow rates and lag times were measured, and morphologic and histologic examinations and TUNEL (terminal deoxynucleotidyl transferase biotin-dUDP nick end labeling) assays were performed. Changes in salivary 99mTc pertechnetate uptake and excretion were followed by single-photon emission computed tomography.Results.Salivary flow rates and lag times to salivation in the EGCG or amifostine groups were better than in the RI-treated group. Histologic examinations of SGs in the EGCG or amifostine group showed more mucin-rich parenchyma and less periductal fibrosis than in the RI-treated group. Fewer apoptotic cells were observed in acini, ducts, and among endothelial cells in the EGCG or amifostine group than in the RI group. In addition, patterns of 99mTc pertechnetate excretion were quite different in the EGCG or amifostine group than in the RI group.Conclusion.EGCG supplementation before RI therapy could protect from RI-induced SG damage in a manner comparable to amifostine, and thus, offers a possible means of preventing SG damage by RI.

Biomodifying effect of epigallocatechin-3-gallate on dentine substrate splicing surface

To investigate the effect of epigallocatechin-3-gallate (EGCG) on biomodification of demineralized dentine substrate, in its permeability, hydrophobicity, and inhibition ability to collagen enzymatic degradation. The dentine substrates were treated with simulated pulpal pressure created by mixtures of 0.02%, 0.1% EGCG/bovine serum albumin (BSA) in acidic environment (pH4.4) for 48 h. A fluid-transport model was used to measure the fluid permeability through demineralized dentine substrate. Positive replicas of dentine substrate were fabricated before and after being subjected to acidic environment for scanning electron microscope (SEM) examination. The blank group contained no EGCG and the positive group were treated with Gluma desensitizer. Static contact angle measurements on demineralized dentin and 0.1% EGCG primed dentin were performed by contact angle analyzer. The priming time were 60 s, 120 s, 0.5 h, 1 h. Dentine specimens bonded with Adper single bond 2 were subjected to 100 mg/L collagenase and observed under SEM. Resin-bonded specimens (with 0.02%, 0.1%, 0.5% EGCG priming, or without EGCG priming) were created for micro-tensile bond strength evaluation (MTBS). Resin-bonded specimens after thermol cycling were created for MTBS evaluation. The fluid permeability in the blank control group increased ([151.3±22.3]%), the fluid permeability in 0.1% EGCG/BSA group decreased ([23.7±6.3]%). Compared to the blank control group, the contact angle of 120 s, 0.5 h, 1 h groups increased by 31.0%, 53.5%, 57.8% in deep dentin and 37.4%, 59.3%, 62.4% in shallow dentin. The SEM examination showed that 0.1% and 0.5% EGCG priming for 120 s significantly increased dentin collagen's resistance to collagenase. The immediate MTBS of 0.1% and 0.5% EGCG groups were (29.4±4.8) and (19.8± 4.9) MPa. After thermol cycling, the MTBS of 0.1% and 0.5% EGCG groups were (19.9±5.1) and (15.3± 6.3) MPa. Under acidic environment (pH4.4), the 0.1% EGCG can reduce dentine permeability under acidic environment. The 0.1% EGCG can increase hydrophobicity of dentin substrate, and strengthen dentin substrate's resistance to collagenase hydrolysis, thus increased the resin-dentin bonding durability.

Epigallocatechin-3-gallate increased the push out bond strength of an epoxy resin sealer to root dentin.

This study aimed to investigate the effect of epigallocatechin-3-gallate (EGCG) from green tea extract on the push out bond strength of an epoxy resin sealer to root dentin. Seventy single root canal premolars were decoronated and instrumented. The roots were randomly irrigated with different final irrigation protocols (n=16): 17%EDTA (EDTA), 17%EDTA followed by 2.5%NaOCl (EDTA+NaOCl), 17%EDTA followed by 1 mg/mL EGCG (EDTA+EGCG) and 1 mg/mL EGCG (EGCG). Other six root canals were received only 2.5%NaOCl as a control group. One root from each group (n=1) was excluded and prepared for SEM investigation. All root canals were then obturated and horizontally sectioned to perform the push out test. EDTA+EGCG group had the highest bond strength (p<0.05). EGCG group showed higher bond strength than EDTA group (p<0.05). The use of EGCG as a final irrigant significantly increased the push out bond strength of an epoxy resin sealer to root dentin.

Green Tea Polyphenol Prevents Diabetic Rats From Acute Kidney Injury After Cardiopulmonary Bypass

Acute kidney injury (AKI) is a common complication accompanying cardiopulmonary bypass (CPB) and is independently associated with increased morbidity and death. Diabetes mellitus increases the risk for AKI after CPB. Epigallocatechin-3-gallate (EGCG) is a major component of the polyphenolic fraction of green tea, which possesses cardioprotective activities, as previously reported. We hypothesized that EGCG also possesses a renoprotective effect through its diverse biochemical properties and assessed the effect on renal function after CPB for diabetic rats. Goto-Kakizaki rats developing type 2 diabetes mellitus were randomly assigned to one of the following groups: sham (n = 10), CPB (CPB alone, n = 9), or EGCG (CPB + EGCG, n = 10). CPB was conducted for 30 minutes at a flow rate of 100 mL/kg/min in the CPB and EGCG groups. Rats assigned to the EGCG group were administrated EGCG solution orally for 2 weeks before CPB. We evaluated renal biochemical or histologic changes at 24 hours after CPB. Compared with the CPB group, the EGCG group exhibited milder tubular injury histologically (p < 0.0001) and reduced expression of kidney injury molecule-1, a biomarker for renal tubular injury (p < 0.0001) and 8-hydroxy-2'-deoxyguanosine (p < 0.01), indicating attenuated oxidant stress. Preoperative oral administration of EGCG ameliorates AKI in a CPB model of diabetic rats through antioxidative properties. This simple method could be applied in a clinical setting as a prophylactic renal protection against AKI after CPB, especially for high-risk patients with diabetes mellitus.

Epigallocatechin gallate attenuates cardiopulmonary bypass–associated lung injury

BackgroundLung dysfunction constitutes a severe complication after major cardiac surgery with cardiopulmonary bypass (CPB), substantially contributing to postoperative morbidity and mortality. The current possibilities of preventive and therapeutic interventions, however, remain insufficient. We, therefore, investigated the effects of intraoperative application of the antioxidant and anti-inflammatory green tea polyphenol (–)–epigallocatechin-3-gallate (EGCG) on CPB-associated lung injury. Materials and methodsThirty piglets (8–15 kg) were divided into four groups: sham-operated and saline-treated control group (n = 7); sham-operated and EGCG-treated control group (EGCG-control group; n = 7); CPB group (n = 10); and CPB + EGCG group (n = 6). The CPB groups underwent 120 min of CPB followed by 90 min of recovery time. In the CPB + EGCG group, EGCG (10 mg/kg body weight) was administered intravenously before and after CPB. Hemodynamic monitoring, blood gas analysis, hematoxylin-eosin staining, and immunohistochemistry of lung tissue were performed. ResultsHistologic examination revealed thickening of the alveolar wall and enhanced alveolar neutrophil infiltration in the CPB group (P < 0.05) compared with those in the control group, which was prevented by EGCG (P < 0.05). In the CPB group, higher formation of poly(ADP-ribose) and nuclear translocation of apoptosis-inducing factor was detected in comparison with those in the control group (P < 0.001), which were both reduced in the CPB + EGCG group (P < 0.001). Compared with the control group, the EGCG-control group showed thickening of the alveolar wall and increased neutrophil infiltration (P < 0.05). ConclusionsCPB leads to lung edema, pulmonary neutrophil infiltration, and presumably initiation of poly(ADP-ribose) polymerase–dependent cell death signaling in the lung. EGCG appears to attenuate CPB-associated lung injury, suggesting that this may provide a novel pharmacologic approach.

Abstract 13343: Green Tea Polyphenol Attenuates Experimental Abdominal Aortic Aneurysm Progression in a Rat Model

Introduction: Destruction of elastin in the media layer is thought to play an important role in the development of abdominal aortic aneurysm (AAA). It has been reported that a major component of green tea, epigallocatechin-3-gallate (EGCG), enhances the stabilization of elastin and facilitates the regeneration of elastin in vitro. However, it is unknown whether EGCG attenuates AAA development in vivo. Hypothesis: We aimed to prove the hypothesis that administration of EGCG can attenuate AAA development. Methods: We divided 48 male SD rats into two groups: the control group (n=24) and the EGCG group (n=24). A 1.0 mmol/L EGCG solution was administered orally for 2 weeks prior to the induction of AAAs in the EGCG group until sacrifice, while tap water was given to the control group. AAAs were induced by administration of intraluminal elastase and extraluminal calcium chloride. Immediately before the induction of the AAAs (on day 0) and on day 7 after their induction, 6 rats were sacrificed in each group. In addition, 12 rats were sacrificed in each group on day 28. The aortic size was measured and aortic tissues underwent biochemical and histological evaluation. Results: The abdominal aortic size on day 28 was significantly smaller in the EGCG group than in the control group (2.34 ± 0.12 vs 2.86 ± 0.19mm, p&lt;.0001). The thickness of the media layer increased significantly in the EGCG group compared with that of the control group (68.4 ± 13.6 vs 46.9 ± 13.6μm, p&lt;0.001). The elastin content of the media layer was significantly greater in the EGCG group than in the control group (20.3 ± 4.8 vs 9.6 ± 3.7%, p&lt;.0001). The lysyl oxidase (LOX) mRNA level in the aortic tissues on day 0 was significantly higher in the EGCG group than in the control group (p&lt;0.05). Transmission electron microscopy images showed the growth of new elastic fibers in the EGCG group. On immunohistochemical staining, the LOX-positive area was significantly larger in the EGCG group than in the control group (p&lt;0.01). Conclusions: Oral treatment with EGCG attenuated AAA progression in a rat model via organization and stabilization of elastin in the media layer by increasing LOX production. Thus, the green tea polyphenol EGCG has the potential to serve as a pharmacological agent to treat and prevent AAAs.

The Effects of N-acetylcystein and Epigallocatechin-3-Gallate in Ischemia-Reperfusion Injury of Rat Lungs

Background: Ischemia-reperfusion injury (IRI) is a major cause of early graft dysfunction after lung transplantation. The aim of this study was to assess the effects of N-acetylcystein (NAC) and epigallocatechin-3-gallate (EGCG) on IRI of rat lungs. Methods: Sprague-Dawley rats were divided into four groups. Sham group (n=6) did not receive IRI. Rats in the control group (n=6), NAC group (n=6), and EGCG group (n=6) were treated with an intraperitoneal injection of normal saline, NAC, and EGCG, respectively, prior to IRI. In the latter three groups, IRI was induced by clamping the left pulmonary artery, vein, and main stem bronchus for a period of 60 minutes. After ischemia, reperfusion and ventilation of the lung was allowed for a period of 180 minutes. The expression levels of inducible nitric oxide synthase (iNOS), hemeoxygenase-1 (HO-1), AMP-activated protein kinase-α (AMPK), and caveolin-1 in lung tissues were evaluated by Western blot. The pathological findings and the extent of pulmonary edema after IRI were compared among the groups. Results: The expression levels of iNOS decreased in the Sham and EGCG groups. The expression level of HO-1 was significantly higher in the EGCG group (P=0.0001). Although the expression levels of AMPK and caveolin-1 showed no differences, the extent of phosphorylation of AMPK and caveolin-1 was higher in the EGCG and NAC groups, respectively. In hematoxylin-eosin staining, the lungs in the NAC and EGCG groups showed fewer alveolar injuries and less hemorrhagic congestion compared with the control group. Conclusions: NAC and EGCG enhanced the phosphorylation of caveolin-1 and AMPK, respectively, and attenuated lung injury induced by ischemia-reperfusion.

Decaffeinated green tea extract rich in epigallocatechin-3-gallate prevents fatty liver disease by increased activities of mitochondrial respiratory chain complexes in diet-induced obesity mice

Nonalcoholic fatty liver disease has been considered the hepatic manifestation of obesity. It is unclear whether supplementation with green tea extract rich in epigallocatechin-3-gallate (EGCG) influences the activity of mitochondrial respiratory chain complexes and insulin resistance in the liver. EGCG regulated hepatic mitochondrial respiratory chain complexes and was capable of improving lipid metabolism, attenuating insulin resistance in obese mice. Mice were divided into four groups: control diet+water (CW) or EGCG (CE) and hyperlipidic diet+water (HFW) or EGCG (HFE). All animals received water and diets ad libitum for 16weeks. Placebo groups received water (0.1ml/day) and EGCG groups (0.1ml EGCG and 50mg/kg/day) by gavage. Cytokines concentrations were obtained by ELISA, protein expression through Western blotting and mitochondrial complex enzymatic activity by colorimetric assay of substrate degradation. HFW increased body weight gain, adiposity index, retroperitoneal and mesenteric adipose tissue relative weight, serum glucose, insulin and Homeostasis Model Assessment of Basal Insulin Resistance (HOMA-IR); glucose intolerance was observed in oral glucose tolerance test (OGTT) as well as ectopic fat liver deposition. HFE group decreased body weight gain, retroperitoneal and mesenteric adipose tissue relative weight, HOMA-IR, insulin levels and liver fat accumulation; increased complexes II-III and IV and malate dehydrogenase activities and improvement in glucose uptake in OGTT and insulin sensitivity by increased protein expression of total AKT, IRα and IRS1. We did not find alterations in inflammatory parameters analyzed. EGCG was able to prevent obesity stimulating the mitochondrial complex chain, increasing energy expenditure, particularly from the oxidation of lipid substrates, thereby contributing to the prevention of hepatic steatosis and improved insulin sensitivity.

Protective effect of epigallocatechin gallate, a major constituent of green tea, against renal ischemia-reperfusion injury in rats.

Background Renal ischemia–reperfusion (I/R) injury plays an important role in the acute kidney injury. The pathogenetic mechanisms potential I/R injury is involved in apoptosis and inflammation. Epigallocatechin gallate (EGCG), a major constituent of green tea, has been shown to have anti-inflammatory and anti-apoptotic activities. This study aimed to explore the underlying effects and mechanisms of EGCG on renal I/R injury in a rat model.Materials and methodsWe induced renal I/R injury in SD rats by clamping the left renal artery for 45 min followed by 24-h reperfusion, along with a contralateral nephrectomy. We randomly allocated 30 rats to three groups (n = 10): sham group, IRI group, and EGCG group. We preconditioned rats intraperitoneally with EGCG (50 mg/kg) or vehicle (50 mg/kg) 45 min before inducing renal ischemia. We collected serum and kidneys at 24 h after reperfusion. Renal function and histologic damage were assessed. We also determined markers of inflammation and apoptosis in kidneys or serum.ResultsEGCG pretreatment can significantly reduce renal dysfunction, histologic change and the expression of tumor necrosis factor-α, IL-1β, IL-6, Bax and cleavage caspase 3 induced by I/R injury and increase the expression of Bax and caspase 3. Moreover, EGCG pretreatment can further induce the activation of p38 mitogen-activated protein kinase in kidney, with no influence on the expression of p38.ConclusionsEGCG treatment can decrease renal ischemia–reperfusion injury by suppressing inflammation and cell apoptosis. Thus, EGCG may represent a potential strategy to reduce renal I/R injury.

Decaffeinated green tea extract rich in epigallocatechin-3-gallate improves insulin resistance and metabolic profiles in normolipidic diet—but not high-fat diet-fed mice

Supplementation with epigallocatechin-3-gallate (EGCG), which restores metabolic profiles, has been proposed as an option for preventing and treating obesity. We investigated whether decaffeinated green tea extract rich in EGCG, attenuates high-fat diet (HFD)-induced metabolic alterations in Swiss mice. The mice were maintained on either a control diet (CD) or HFD for 8weeks and supplemented with either a placebo or EGCG (50mg/kg/day). Body weight, serum lipid profiles, cytokine protein expression, and content in epididymal (EPI) and retroperitoneal (RET) adipose tissues, and adipocyte area were measured. The body weights of HFD + placebo-fed mice were increased compared with those of HFD + EGCG-fed mice (28 and 21%, respectively), whereas the body weights of CD + EGCG-fed mice were decreased 16% compared with those of the CD + placebo group. Serum triglyceride levels were decreased 32% in the CD + EGCG group compared with the CD + placebo group. Compared with the CD + placebo group, increased phosphorylation of AMPK and hormone-sensitive lipase in EPI and RET, respectively, was found in the CD + EGCG group. Increased acetyl-CoA carboxylase phosphorylation was observed in both adipose tissues. In addition, TNF-α and IL-10 levels in EPI and adiponectin levels were higher in the CD + EGCG group than in the CD + placebo group. TNF-α levels were lower in the HFD + EGCG group than in the HFD + placebo group. Furthermore, the CD + EGCG group exhibited a lower adipocyte area than the CD + placebo group. These indicate that the effects of decaffeinated green tea extract on body mass may be related to the crosstalk between lipolytic and inflammatory pathways in normolipidic diet-fed mice but not in HFD-fed mice.

The Green Tea Polyphenol Epigallocatechin-3-Gallate (EGCg) Attenuates Skeletal Muscle Atrophy in a Rat Model of Sarcopenia.

Sarcopenia-the loss of muscle mass and functionality occurring with age-is a pervasive problem with few effective treatments beyond exercise. We examined the ability of the green tea catechin, epigallocatechin-3-gallate (EGCg), to impact muscle mass and the molecular pathway involved in muscle atrophy in a rat model of sarcopenia. 20-month-old Sprague-Dawley rats were treated for 8 weeks with control diet or control plus 200mg/kg body weight of EGCg diet. EGCg-supplemented animals had significantly greater gastrocnemius muscle mass than the aged controls, and showed a trend for increased muscle fiber cross-sectional areas (CSA) (p=0.06). These changes were associated with significantly lower protein expressions of the intramuscular 19S and 20S proteasome subunits and the MuRF1 and MAFbx ubiquitin ligases in the EGCg-treated animals. Proteasome activity as determined by 'Chymotrypsin-like' enzyme activity was also significantly reduced by EGCg. Muscle mRNA expression of IL-15 and IGF-1 were significantly increased in the EGCg group vs. the aged controls. In comparison to younger adult animals (6 month), the protein expression of 19S, 20S, MuRF1, MAFbx, and myostatin were increased between approximately 4- and 12-fold in the aged controls, but only up to ~2-fold in the aged EGCg animals. EGCg supplementation was able to preserve muscle in sarcopenic rats, partly through attenuating protein degradation via the ubiquitin-proteasome pathway, together with increased expression of anabolic factors.

Neuroprotective Properties of the Standardized Extract from Camellia sinensis (Green Tea) and Its Main Bioactive Components, Epicatechin and Epigallocatechin Gallate, in the 6-OHDA Model of Parkinson's Disease.

Camellia sinensis (green tea) is largely consumed, mainly in Asia. It possesses several biological effects such as antioxidant and anti-inflammatory properties. The objectives were to investigate the neuroprotective actions of the standardized extract (CS), epicatechin (EC) and epigallocatechin gallate (EGCG), on a model of Parkinson's disease. Male Wistar rats were divided into SO (sham-operated controls), untreated 6-OHDA-lesioned and 6-OHDA-lesioned treated for 2 weeks with CS (25, 50, or 100 mg/kg), EC (10 mg/kg), or EGCG (10 mg/kg) groups. One hour after the last administration, animals were submitted to behavioral tests and euthanized and their striata and hippocampi were dissected for neurochemical (DA, DOPAC, and HVA) and antioxidant activity determinations, as well as immunohistochemistry evaluations (TH, COX-2, and iNOS). The results showed that CS and catechins reverted behavioral changes, indicating neuroprotection manifested as decreased rotational behavior, increased locomotor activity, antidepressive effects, and improvement of cognitive dysfunction, as compared to the untreated 6-OHDA-lesioned group. Besides, CS, EP, and EGCG reversed the striatal oxidative stress and immunohistochemistry alterations. These results show that the neuroprotective effects of CS and its catechins are probably and in great part due to its powerful antioxidant and anti-inflammatory properties, pointing out their potential for the prevention and treatment of PD.