Oral Epigallocatechin-3-gallate Research Articles

Gut Microbiota-Derived D-Tagatose from EGCG Attenuates Radiation-Induced Intestinal Injury

As a rapidly self-renewing tissue, the small intestine is particularly sensitive to ionizing radiation, which limits the outcomes of radiotherapy against abdominal malignancies, resulting in poor prognosis. The polyphenol (-)-epigallocatechin-3-gallate (EGCG), a major bioactive constituent of green tea, is beneficial in radiation-induced intestinal injury (RIII) alleviation. However, the bioavailability of EGCG in vivo is very low, with only 0.1% to 1.6% being absorbed into the intestine of mice. It is unclear whether gut microbial metabolites mediated by EGCG exert an effect to protect against radiation-induced intestinal injury. Male C57BL/6J mice were subjected to 13 Gy abdominal irradiation after EGCG gavage, and the severity of intestinal tissue damage was evaluated by HE staining, immunohistochemistry, and TUNEL assays. Fresh fecal samples were collected after the end of gavage, and then fecal sterile fecal filtrate (SFF) was obtained. Stool samples were collected 3 d after irradiation. The gut microbiome was detected by 16S rRNA sequencing, the metabolites were detected by GC‒MS analysis, and then the metabolites were applied to male C57BL/6J mice, observing and evaluating the severity of RIII. We first explored the effect of oral EGCG delivery on radiation-induced intestinal injury. Our results revealed that EGCG pre-supplementation prolongs survival time, prevents weight loss in mice and mitigates radiation-induced intestinal injury in irradiated mice. Using 16S rRNA gene-based microbiota analysis, we first found that EGCG ameliorated ionizing radiation-induced gut microbiota dysbiosis and enriched short-chain fatty acid (SCFA)-producing bacteria such as Roseburia, Ruminococcus, and Clostridia_UCG-014. In addition, metabolomic profiling analysis showed that the gut microbiota modulated EGCG-induced metabolic reprogramming in colonic tissues, particularly by enhancing galactose metabolism. Notably, EGCG supplementation resulted in the enrichment of the microbiota-derived galactose metabolism metabolite D-tagatose. Furthermore, exogenous treatment with D-tagatose reproduced similar protective effects as EGCG to protect against radiation-induced intestinal injury (RIII). D-tagatose restored the length of villi and improved the number of goblet cells, Ki-67-positive cells and Lgr5+ ISCs, while the number of TUNEL-positive cells in the intestinal tissues decreased significantly. To validate these discoveries, we performed fecal sterile fecal filtrate (SFF) from EGCG-dosed mice to untreated mice before ionizing radiation. SFF from EGCG-dosed mice alleviated the RIII over SFF from control mice superiorly. This study provides the first data indicating that oral EGCG ameliorated radiation-induced intestinal injury (RIII) by regulating the gut microbiota and metabolites. Our findings provide novel insights into D-tagatose derived by gut microbiota from EGCG-mediated remission of RIII.

Gut microbiota from green tea polyphenol-dosed mice improves intestinal epithelial homeostasis and ameliorates experimental colitis

BackgroundAlteration of the gut microbiota may contribute to the development of inflammatory bowel disease (IBD). Epigallocatechin-3-gallate (EGCG), a major bioactive constituent of green tea, is known to be beneficial in IBD alleviation. However, it is unclear whether the gut microbiota exerts an effect when EGCG attenuates IBD.ResultsWe first explored the effect of oral or rectal EGCG delivery on the DSS-induced murine colitis. Our results revealed that anti-inflammatory effect and colonic barrier integrity were enhanced by oral, but not rectal, EGCG. We observed a distinct EGCG-mediated alteration in the gut microbiome by increasing Akkermansia abundance and butyrate production. Next, we demonstrated that the EGCG pre-supplementation induced similar beneficial outcomes to oral EGCG administration. Prophylactic EGCG attenuated colitis and significantly enriched short-chain fatty acids (SCFAs)-producing bacteria such as Akkermansia and SCFAs production in DSS-induced mice. To validate these discoveries, we performed fecal microbiota transplantation (FMT) and sterile fecal filtrate (SFF) to inoculate DSS-treated mice. Microbiota from EGCG-dosed mice alleviated the colitis over microbiota from control mice and SFF shown by superiorly anti-inflammatory effect and colonic barrier integrity, and also enriched bacteria such as Akkermansia and SCFAs. Collectively, the attenuation of colitis by oral EGCG suggests an intimate involvement of SCFAs-producing bacteria Akkermansia, and SCFAs, which was further demonstrated by prophylaxis and FMT.ConclusionsThis study provides the first data indicating that oral EGCG ameliorated the colonic inflammation in a gut microbiota-dependent manner. Our findings provide novel insights into EGCG-mediated remission of IBD and EGCG as a potential modulator for gut microbiota to prevent and treat IBD.1weu4UfF6nDLmdPiHVjMmdVideo

Cerebral Cortex Apoptosis in Early Aged Hypertension: Effects of Epigallocatechin-3-Gallate.

This study aimed to investigate cerebral cortex apoptosis on the early aged hypertension and the effects of green tea flavonoid epigallocatechin-3-gallate (EGCG). Twenty-four rats were divided into three groups: a control Wistar-Kyoto group (WKY, n = 8), a spontaneously early aged hypertensive group (SHR, n = 8), and an early aged hypertension with EGCG treatment group (SHR-EGCG, n = 8; daily oral EGCG 200 mg/kg—94%, 12 weeks). At 48 weeks old, blood pressures (BPs) were evaluated and cerebral cortexes were isolated for TUNEL assay and Western blotting. Systolic, diastolic, and mean blood pressure levels in the SHR-EGCG were reduced compared to the SHR. The percentage of neural cell deaths, the levels of cytosolic Endonuclease G, cytosolic AIF (Caspase-independent apoptotic pathway), Fas, Fas Ligand, FADD, Caspase-8 (Fas-mediated apoptotic pathway), t-Bid, Bax/Bcl-2, Bak/Bcl-xL, cytosolic Cytochrome C, Apaf-1, Caspase-9 (Mitochondrial-mediated apoptotic pathway), and Caspase-3 (Fas-mediated and Mitochondria-mediated apoptotic pathways) were increased in the SHR relative to WKY and reduced in SHR-EGCG relative to SHR. In contrast, the levels of Bcl-2, Bcl-xL, p-Bad, 14-3-3, Bcl-2/Bax, Bcl-xL/Bak, and p-Bad/Bad (Bcl-2 family-related pro-survival pathway), as well as Sirt1, p-PI3K/PI3K and p-AKT/AKT (Sirt1/PI3K/AKT-related pro-survival pathway), were reduced in SHR relative WKY and enhanced in SHR-EGCG relative to SHR. In conclusion, green tea flavonoid epigallocatechin-3-gallate (EGCG) might prevent neural apoptotic pathways and activate neural survival pathways, providing therapeutic effects on early aged hypertension-induced neural apoptosis.

Oral epigallocatechin gallate reduces intestinal nadolol absorption via modulation of Oatp1a5 and Oct1 transcriptional levels in spontaneously hypertensive rats

BackgroundConcurrent use of epigallocatechin-3-gallate (EGCG) and medication may lead to botanical-drug interactions, subsequently therapeutic failure or drug toxicity. It has been reported that EGCG reduces plasma nadolol bioavailability in normotensive models. Nevertheless, evidence on the effects of EGCG on hypertensive model, and the possible underlying mechanism have not been elucidated. ObjectivesThis study aims (i) to investigate the effects of EGCG on nadolol pharmacokinetics (maximum plasma concentration, time to achieve maximum concentration, area under the time-plasma concentration curve, plasma half-life and total clearance) and subsequently its impact on blood pressure control; and (ii) to identify transcriptional regulatory roles of EGCG on the nadolol intestinal and hepatic drug-transporters in SHR. MethodsMale SHR were pre-treated with a daily dose of EGCG (10 mg/kg body weight, i.g.) for 13 days. On day-14, a single dose of nadolol (10 mg/kg body weight) was given to the rats 30 min after the last dose of EGCG administration. Systolic blood pressure (SBP) was measured at 6-h and 22-h post-nadolol administration. Plasma and urinary nadolol concentrations were quantified using high-performance liquid chromatography, and pharmacokinetic parameters were analyzed by using non-compartmental analysis. Hepatic and ileal Oatp1a5, P-gp, and Oct1 mRNA expressions were determined by real-time PCR. ResultsSBP of SHR pre-treated with EGCG and received nadolol was significantly higher than those which were not pre-treated with EGCG but received nadolol. Pre-treatment of EGCG resulted in a marked reduction of plasma nadolol maximum concentration (Cmax) and area under the time-plasma concentration curve (AUC) by 53% and 51% compared to its control. The 14-day treatment with oral EGCG led to a significant downregulation of mRNA levels of ileal Oatp1a5, P-gp, and Oct1 genes by 4.03-, 8.01- and 4.03-fold; and hepatic P-gp, and Oct1 genes by 2.61- and 2.66-fold. ConclusionThese data concluded that exposure to EGCG could lead to reduced nadolol bioavailability and therefore, uncontrolled raised blood pressure and higher risks of cardiovascular events. Our data suggest that the reduced nadolol bioavailability is associated with the downregulation of ileal Oatp1a5 and Oct1 mRNA levels that subsequently lead to poor absorption of nadolol to the systemic circulation.

Efficacy of oral epigallocatechin-3-gallate solution administration during radiotherapy for non-small-cell lung cancer patients: A long-term observational study

ObjectiveSeveral studies have found that epigallocatechin-3-gallate (EGCG) can alleviate acute radiation-induced esophagitis, inhibit pulmonary inflammation and fibrosis, and reduce the severity of cardiovascular disease. Therefore, this study was aimed at exploring the influence of EGCG on late radiation toxicity in the heart, esophagus, and lungs among patients with locally advanced lung cancer. MethodsThe patients were divided into an EGCG group and a control group, the groups received EGCG and symptomatic treatment, respectively. The Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer Late Radiation Morbidity Scoring Scheme was used to determine the late toxicity scores. Tumor responses were evaluated by chest computed tomography (CT), based on the Response Evaluation Criteria in Solid Tumors version 1.1. ResultsWe retrospectively analyzed 74 patients treated at our hospital from September 2012 to September 2016 (37 patients received EGCG and 37 received supportive treatment). The late toxicity scores of the EGCG group decreased compared to those of the control group. An obvious clinical significance was observed for the oral EGCG solution in the treatment and prevention of late cardiac, esophageal, and pulmonary toxicity. However, no significant difference was found (P ​> ​0.05). The tumor response rates were similar in the two groups. Moreover, there was no difference in progression-free survival (PFS) between the groups (P ​> ​0.05). ConclusionOral EGCG solution might alleviate radiation-induced late cardiac, esophageal, and pulmonary toxicity but has no significant effect on the tumor response rate and PFS following radiotherapy.

Assessing the analgesic efficacy of oral epigallocatechin-3-gallate on epidural catheter analgesia in patients after surgical stabilisation of multiple rib fractures: a prospective double-blind, placebo-controlled clinical trial

Context Thoracic trauma results in multiple rib fractures (MRF), and surgical stabilisation of rib fractures (SSRF) can relieve fracture pain. Epigallocatechin-3-gallate (EGCG) is reported to exhibit beneficial effects in bone-related metabolic and differentiation processes. Objective To study the clinical effect of EGCG on regional analgesia for pain relief in MRF patients after SSRF. Materials and methods Ninety-seven MRF patients (61 males, 36 females) who were on epidural catheter analgesia after SSRF were recruited. They were randomly divided into: oral EGCG 100 mg (oral grade) twice daily for 10 days and placebo groups. Pain scores, incentive spirometry (IS) volumes, respiratory rate and oxygen saturation (SpO2) were assessed day 10 after SSRF. Results Comparing results from the placebo and EGCG group, in the 10-day intervention course, oral EGCG reduced pain score (8 at base line vs. 4 at end of intervention in EGCG group, p < 0.05; 4 in EGCG group vs. 6 in placebo group at end of intervention, p < 0.05), improved IS volume (713 at base line vs. 1072 at end of intervention in EGCG group, p < 0.05; 1072 in EGCG group vs. 953 in placebo group at end of intervention, p < 0.05) and respiratory rate (24 at base line vs. 15 at end of intervention in EGCG group, p < 0.05; 15 in EGCG group vs. 19 in placebo group at end of intervention, p < 0.05). However, no further enhancing effect on SpO2 was observed in the EGCG group (0.98 in EGCG group vs. 0.98 in placebo group at end of intervention, p > 0.05). Discussion and conclusions Although the study is limited by a relatively small sample size and lack of serum factor analysis, the key results and the study design, for the first time, nevertheless pave the way for trials with larger number of patients to understand the effect of EGCG in MRF patients that are undergoing SSRF.

Epigallocatechin-3-gallate, a prototypic chemopreventative agent for protection against cisplatin-based ototoxicity

Cisplatin-induced ototoxicity is one of the major factors limiting cisplatin chemotherapy. Ototoxicity results from damage to outer hair cells (OHCs) and other regions of the cochlea. At the cellular level, cisplatin increases reactive oxygen species (ROS) leading to cochlear inflammation and apoptosis. Thus, ideal otoprotective drugs should target oxidative stress and inflammatory mechanisms without interfering with cisplatin's chemotherapeutic efficacy. In this study, we show that epigallocatechin-3-gallate (EGCG) is a prototypic agent exhibiting these properties of an effect otoprotective agent. Rats administered oral EGCG demonstrate reduced cisplatin-induced hearing loss, reduced loss of OHCs in the basal region of the cochlea and reduced oxidative stress and apoptotic markers. EGCG also protected against the loss of ribbon synapses associated with inner hair cells and Na+/K+ ATPase α1 in the stria vascularis and spiral ligament. In vitro studies showed that EGCG reduced cisplatin-induced ROS generation and ERK1/2 and signal transducer and activator of transcription-1 (STAT1) activity, but preserved the activity of STAT3 and Bcl-xL. The increase in STAT3/STAT1 ratio appears critical for mediating its otoprotection. EGCG did not alter cisplatin-induced apoptosis of human-derived cancer cells or cisplatin antitumor efficacy in a xenograft tumor model in mice because of its inability to rescue the downregulation of STAT3 in these cells. These data suggest that EGCG is an ideal otoprotective agent for treating cisplatin-induced hearing loss without compromising its antitumor efficacy.

Dietary pretreatment with green tea polyphenol, (−)-epigallocatechin-3-gallate reduces the bioavailability and hepatotoxicity of subsequent oral bolus doses of (−)-epigallocatechin-3-gallate

Human case-studies have reported an association between green tea-based dietary supplements and hepatotoxicity. Studies have demonstrated the hepatotoxicity of high-dose oral bolus dosing with the tea polyphenol (−)-epigallocatechin-3-gallate (EGCG) in mice and dogs. We examined the effect of pretreatment with dietary EGCG on the hepatotoxicity and bioavailability of acute oral bolus dosing with EGCG in CF-1 mice. EGCG (750 mg/kg, i.g., once daily for 3 days) increased plasma alanine aminotransferase by 80-fold, decreased both reduced (by 59%) and total (by 33%) hepatic glutathione, and increased hepatic levels of phosphorylated histone 2AX. Pretreatment with dietary EGCG (3.2 mg/g diet) for 2 weeks mitigated hepatotoxicity. Acute oral EGCG also decreased mRNA expression of glutathione reductase. Dietary pretreatment prevented these decreased and increased glutathione peroxidase (Gpx)2, Gpx3, Gpx5, and Gpx7 expression. We found that dietary EGCG reduced the plasma (57% reduction) and hepatic (71% reduction) EGCG exposure following oral bolus dosing compared to mice that were not pre-treated. Overall, it appears that EGCG can modulate its own bioavailability and that dietary treatment may reduce the toxic potential of acute high oral bolus doses of EGCG. These data may partly explain the observed variation in hepatotoxic response to green tea-containing dietary supplements.

Preparation of epigallocatechin gallate-loaded nanoparticles and characterization of their inhibitory effects on Helicobacter pylori growth in vitro and in vivo

A variety of approaches have been proposed for overcoming the unpleasant side effects associated with antibiotics treatment of Helicobacter pylori (H. pylori) infections. Research has shown that epigallocatechin-3-gallate (EGCG), a major ingredient in green tea, has antibacterial activity for antiurease activity against H. pylori. Oral EGCG is not good because of its digestive instability and the fact that it often cannot reach the targeted site of antibacterial activity. To localize EGCG to H. pylori infection site, this study developed a fucose–chitosan/gelatin nanoparticle to encapsulate EGCG at the target and make direct contact with the region of microorganisms on the gastric epithelium. Analysis of a simulated gastrointestinal medium indicated that the proposed in vitro nanocarrier system effectively controls the release of EGCG, which interacts directly with the intercellular space at the site of H. pylori infection. Meanwhile, results of in vivo clearance assays indicated that our prepared fucose–chitosan/gelatin/EGCG nanoparticles had a significantly greater H. pylori clearance effect and more effectively reduced H. pylori-associated gastric inflammation in the gastric-infected mouse model than the EGCG solution alone.

Effect of dietary (‐)‐epigallocatechin‐3‐gallate (EGCG) pretreatment on the hepatotoxicity of acute high dose EGCG (270.3)

Green tea based dietary supplements containing high levels of (‐)‐epigallocatechin‐3‐gallate (EGCG) have become popular for weight loss. Case‐studies have reported hepatotoxicity associated with consumption of green tea‐based supplements and laboratory studies have demonstrated the potential hepatotoxicity of EGCG. We examined the effect of pretreatment with dietary EGCG on the bioavailability and hepatotoxicity of high oral bolus EGCG in CF‐1 mice. EGCG (750 mg/kg, i.g., once daily) for 3 d increased plasma alanine aminotransferase by 80‐fold compared to controls. High dose EGCG also decreased hepatic levels of reduced (59% decrease) and total glutathione (33% decrease), and increased hepatic phosphorylation of histone 2AX compared to vehicle‐treated control mice. Pretreatment with dietary EGCG (3.2 mg/g) for 2 wk blunted these changes. EGCG pretreatment also raised the levels of several oxidative stress‐related genes. Analysis of plasma and liver levels of EGCG showed that pretreatment with dietary EGCG reduced the peak plasma (38% reduction) and hepatic (57% reduction) EGCG concentrations following oral bolus dosing. In conclusion, EGCG appears to modulate its own bioavailability and chronic exposure to dietary EGCG may reduce the hepatotoxic potential of high oral bolus EGCG. These data may help explain the variation in sensitivity of human subjects to green tea‐containing supplements.Grant Funding Source: NIH AT004678

P3-17-07: EGCG, a Green Tea Antioxidant Suppresses Breast Tumor Angiogenesis and Growth Via Inhibiting the Activation of HIF-1a and NFκB, and VEGF Expression.

Abstract Background Cancer cells are under greater oxidative stress than normal cells. Limited studies have showed that epigallocatechin-3-gallate (EGCG), a green tea antioxidant can afford protection against a variety of cancer types. The role of EGCG in breast cancer therapy is poorly understood. The present study tests the hypothesis that EGCG as an antioxidant can inhibit the activation of HIF-1α and NFκB, and VEGF expression, thereby suppressing tumor angiogenesis and breast cancer progression. Material and Methods: 16 eight-wk-old female mice (C57BL/6J) were inoculated with 10^6 E0771 (mouse breast cancer) cells in the left fourth mammary gland fat pad. 8 mice received EGCG at 50–100 mg/kg/d in drinking water for 4 weeks. 8 control mice received drinking water only. Tumor size was monitored using dial calipers. At the end of the experiment, blood samples, tumors, heart and limb muscles were collected for measuring VEGF expression using ELISA and capillary density (CD) using CD31 immunochemistry. Cultured E0771 cells were used for determining the direct effects of EGCG on proliferation (3H-thymidine incorporation), migration (Matrigel assay), VEGF expression (ELISA), the activation of HIF-1α and NFκB (motif binding assays, Active Motif). MCF-7 and MDA-MB-231 cells were also used for 3H-thymidine incorporation. Results: Oral EGCG treatment significantly reduced tumor weight over the control (0.37±0.15 vs. 1.16±0.30 g; P&amp;lt;0.01), tumor CD (109±20 vs. 156±12 capillary #/mm^2; P&amp;lt;0.01), tumor VEGF expression (45.72±1.4 vs. 59.03±3.8 pg/mg; P&amp;lt;0.01), respectively. EGCG treatment reduced plasma VEGF levels over the control mice (26.48±3.76 vs. 40.79±3.5 pg/ml; P&amp;lt;0.01). However, there were no differences in the body weight and heart weight between EGCG and the control groups. EGCG did not inhibit angiogenesis and VEGF expression in the heart and skeletal muscle of mice, compared to the control. EGCG at 50 mmol/L significantly inhibited the activation of HIF-1α (0.11±0.02 vs. 0.24±0.02; P&amp;lt;0.01) and NFκB (1.15±0.21 vs. 1.61±0.32; P&amp;lt;0.01) as well as VEGF expression (1752±49 vs. 2254±91 pg/mg; P&amp;lt;0.01) in cultured E0771 cells, compared to the control, respectively. EGCG caused a dose-related inhibition on the proliferation and migration in cultured E0771 cells. EGCG also caused a dose-related inhibition on the proliferation in cultured MCF-7 and MDA-MB-231 cells. Discussion: These findings support the hypothesis that EGCG, a green tea antioxidant, directly targets both tumor cells and tumor vasculature, thereby inhibiting tumor growth, proliferation, migration, and angiogenesis of breast cancer, which is mediated by the inhibition of HIF-1α and NFκB activation as well as VEGF expression. Interestingly, oral EGCG treatment has no effects on the body weight, heart weight, angiogenesis and VEGF expression in the heart and skeletal muscle of mice. This work will have important implications for translating EGCG therapy to human breast cancer treatment and prevention. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-17-07.

The Preventive Effect of Oral EGCG in a Fetal Alcohol Spectrum Disorder Mouse Model

Fetal alcohol spectrum disorder (FASD) is a challenging public health problem. Previous studies have found an association between FASD and oxidative stress. In the present study, we assessed the role of oxidative stress in ethanol-induced embryonic damage and the effect of (-)-epigallocatechin-3-gallate (EGCG), a powerful antioxidant extracted from green tea, on the development of FASD in a murine model. Pregnant female mice were given intraperitoneal ethanol (25%, 0.005 to 0.02 ml/g) on gestational day 8 (G8) to establish the FASD model. On G10.25, mice were sacrificed and embryos were collected and photographed to determine head length (HL), head width (HW), and crown rump length (CRL). For mice given EGCG, administration was through a feeding tube on G7 and G8 (dose: 200, 300, or 400 mg/kg/d, the total amount for a day was divided into 2 equal portions). G10.25 embryos were evaluated morphologically. Brain tissues of G9.25 embryos were used for RT-PCR and western blotting of neural marker genes and proteins and detection of oxidative stress indicators. Administration of ethanol to pregnant mice on G8 led to the retardation of embryonic growth and down-regulation of neural marker genes. In addition, administration of ethanol (0.02 ml/g) led to the elevation of oxidative stress indicators [hydrogen peroxide (H₂O₂) and malondialdehyde (MDA)]. Administration of EGCG on G7 and G8 along with ethanol on G8 ameliorated the ethanol-induced growth retardation. Mice given EGCG (400 mg/kg/d) along with ethanol had embryo sizes and neural marker genes expression similar to the normal controls. Furthermore, EGCG (400 mg/kg on G7 and G8) inhibited the increase in H₂O₂ and MDA. In a murine model, oxidative stress appears to play an important role in ethanol-induced embryonic growth retardation. EGCG can prevent some of the embryonic injuries caused by ethanol.

Oral Administration of EGCG, an Antioxidant Found in Green Tea, Inhibits Tumor Angiogenesis and Growth of Breast Cancer in Female Mice

Oxidative stress has been implicated in promoting growth and malignancy of cancers including breast cancer. We evaluated whether oral administration of epigallocatechin‐3‐gallate (EGCG), an antioxidant found in green tea, inhibits vascular endothelial growth factor (VEGF) expression, tumor angiogenesis, and growth of breast cancer in female mice. 7‐wk‐old female mice (C57BL) were given EGCG 25mg/50ml in drinking water for 5 wks, which was around 50–100 mg/kg/day. The control mice received regular drinking water. In the 2nd wk, ~1×10^5 E0771 (mouse breast cancer) cells were injected in 4th mammary gland of the mice. Tumor size was monitored by measuring tumor cross section area (TCSA). In the end, the tumors were isolated for measuring tumor weight, intratumoral microvessel (IM) density using CD31 immunohistochemistry staining, and VEGF protein levels using ELISA. Oral EGCG treatment caused the significant decreases in TCSA (66%), in tumor weight (68%), in IM density (155±6 vs. 111±20 IM#/mm^2), and in VEGF protein levels (59.0±3.7 vs. 45.7±1.4 pg/mg) of breast tumors, compared to the control, respectively (N = 8; P&lt;0.01). VEGF plasma levels were lower in EGCG mice than control mice (40.8±3.5 vs. 26.5±3.8 pg/ml; P&lt;0.01). The results suggest that antioxidant treatment with EGCG significantly inhibits breast cancer progression via reducing VEGF expression and tumor angiogenesis. (NIH/AA013821 &amp; NIH/HL 51971)

Chemotherapy Enhances CD8+ T Cell-mediated Antitumor Immunity Induced by Vaccination With Vaccinia Virus

The use of immunotherapy or chemotherapy alone is generally ineffective against well-established tumors. To overcome this intrinsic resistance against therapy for tumors, we have attempted to combine immunotherapy with chemotherapy. In this study, we tried to induce a rapid antitumor effect via chemoimmunotherapy using a vaccinia viral vaccine as an immunotherapeutic agent with anticancer agents including epigallocatechin-3-gallate (EGCG) and conventional anticancer drugs. Although a combination of vaccinia-mediated vaccination and chemotherapy led to a strong inhibition of tumor growth, monotherapy alone failed to completely cure tumors. In contrast, intravenous injection of cisplatin (CDDP) or cyclophosphamide (CTX) after vaccinia virus vaccination led to complete regression of the established tumors. Interestingly, anticancer drugs appear to augment the antitumor effect of the vaccinia virus-mediated immunotherapy. This effect is mainly associated with the enhanced tumor-specific CD8(+) T cell immune response induced by vaccinia virus, which was demonstrated by antibody depletion. However, anticancer drugs alone failed to induce a significant enhancement of the tumor-specific CD8(+) T cell immune response. Taken together, these results suggest that combining vaccinia virus-based immunotherapy with anticancer drugs is particularly effective against established tumors by increasing the tumor antigen-specific CD8(+) T cell immune response, which is primed by vaccinia virus-mediated vaccination.

Epigallocatechin-3-Gallate Enhances CD8+ T Cell–Mediated Antitumor Immunity Induced by DNA Vaccination

Immunotherapy and chemotherapy are generally effective against small tumors in animal models of cancer. However, these treatment regimens are generally ineffective against large, bulky tumors. We have found that a multimodality treatment regimen using DNA vaccination in combination with chemotherapeutic agent epigallocatechin-3-gallate (EGCG), a compound found in green tea, is effective in inhibiting large tumor growth. EGCG was found to induce tumor cellular apoptosis in a dose-dependent manner. The combination of EGCG and DNA vaccination led to an enhanced tumor-specific T-cell immune response and enhanced antitumor effects, resulting in a higher cure rate than either immunotherapy or EGCG alone. In addition, combined DNA vaccination and oral EGCG treatment provided long-term antitumor protection in cured mice. Cured animals rejected a challenge of E7-expressing tumors, such as TC-1 and B16E7, but not a challenge of B16 7 weeks after the combined treatment, showing antigen-specific immune responses. These results suggest that multimodality treatment strategies, such as combining immunotherapy with a tumor-killing cancer drug, may be a more effective anticancer strategy than single-modality treatments.

Neutrophil Restraint by Green Tea: Inhibition of Inflammation, Associated Angiogenesis, and Pulmonary Fibrosis

Neutrophils play an essential role in host defense and inflammation, but the latter may trigger and sustain the pathogenesis of a range of acute and chronic diseases. Green tea has been claimed to exert anti-inflammatory properties through unknown molecular mechanisms. We have previously shown that the most abundant catechin of green tea, (-)epigallocatechin-3-gallate (EGCG), strongly inhibits neutrophil elastase. Here we show that 1) micromolar EGCG represses reactive oxygen species activity and inhibits apoptosis of activated neutrophils, and 2) dramatically inhibits chemokine-induced neutrophil chemotaxis in vitro; 3) both oral EGCG and green tea extract block neutrophil-mediated angiogenesis in vivo in an inflammatory angiogenesis model, and 4) oral administration of green tea extract enhances resolution in a pulmonary inflammation model, significantly reducing consequent fibrosis. These results provide molecular and cellular insights into the claimed beneficial properties of green tea and indicate that EGCG is a potent anti-inflammatory compound with therapeutic potential.