Immunoregulatory Effect and Mechanism of Epigallocatechin-3-Gallate in A Mouse Oral Cancer Model

Objective:This investigation delineates the anti-cancer potency of epigallocatechin-3-gallate(EGCG)in an oral cancer mouse model,with a focus on its effect on T-cell activation.Methods:An oral cancer model was established in male Balb/c mice using 4-nitroquinoline 1-oxide(4-NQO).The mice were systematically grouped and administered graded concentrations of EGCG.Key parameters such as body weight,hydration levels,tumor volume,and mass were meticulously tracked.T-cell activity and cytokine expression profiles,focusing on interleukin-2(IL-2),interferon-gamma(IFN-γ),and tumor necrosis factor-alpha(TNF-α),were quantified using ELISA.A comprehensive statistical evaluation included one-way ANOVA,Tukey’s HSD multiple comparison test,and the Kruskal-Wallis non-parametric assessment.Results:EGCG-administered cohorts exhibited a pronounced reduction in tumor size and mass,with the high-dose group showing the greatest efficacy.ELISA findings corroborated a significant increase in T-cell activity and concomitant upregulation of key cytokines,including IL-2,IFN-γ,and TNF-α(P<0.05).Conclusion:This investigation confirms the tumor-suppressive efficacy of EGCG in a murine oral squamous cell carcinoma model.The therapeutic effects of EGCG are mediated through T-cell activation and the upregulation of pivotal cytokine expression,highlighting its potential immunomodulatory role in oral cancer treatment.

Epigallocatechin-3-gallate exerts antihypertensive effects and improves endothelial function in spontaneously hypertensive rats

Objective:To investigate the effect of epigallocatechin-3-gallate(EGCG)on endothelial dysfunction in spontaneously hypertensive rats(SHR).Methods:Wistar-Kyoto(WKY)rats and SHR were divided into four groups;WKY control,SHR control and SHR treated with EGCG(50 mg/kg/day)or losartan(10 mg/kg/day).The treatment was given daily for 4 weeks by oral gavage and the blood pressure was monitored by tail-cuff method every 3 days.Acetylcholineinduced endothelium-dependent relaxations were assessed in isolated phenylephrine-precontracted aortic rings at the end of treatment.The vascular levels of reactive oxygen species,nitric oxide,tetrahydrobiopterin,and cyclic guanosine monophosphate were also measured.Moreover,the expression of angiotensinⅡtype 1(AT_(1))receptor protein was determined.Results:The systolic blood pressure was significantly decreased in SHR treated with EGCG.The impaired endothelium-dependent relaxation was significantly improved in aortic ring isolated from the EGCG-treated SHR group.EGCG also significantly increased the levels of nitric oxide,tetrahydrobiopterin,and cyclic guanosine monophosphate,while decreasing the level of reactive oxygen species and the protein expression of AT_(1)receptor in SHR.Conclusions:EGCG attenuates endothelial dysfunction in SHR by decreasing oxidative stress and increasing vascular nitric oxide bioavailability,which may be modulated partly by inhibition of vascular AT_(1)receptors.An increase in endothelium-dependent relaxation may contribute to a decrease in blood pressure in hypertensive animals.

(-)-Epigallocatechin-3-gallate inhibits growth of gastric cancer by reducing VEGF production and angiogenesis

AIM： To investigate the effect of （-）-epigallocatechin-3-gallate （EGCG） on growth of gastric cancer and its possible mechanism. METHODS： Heterotopic tumors were induced by subcutaneously injection of SGC-7901 cells in nude mice. Tumor growth was measured by calipers in two dimensions. Tumor angiogenesis was determined with tumor microvessel density （MVD） by immunohistology. Vascular endothelial growth factor （VEGF） protein level and activation of signal transducer and activator of transcription 3 （Star3） were examined by Western blotting. VEGF mRNA expression was determined by RT-PCR and VEGF release in tumor culture medium by ELISA. VEGF-induced cell proliferation was studied by MTT assay, cell migration by gelatin modified Boyden chamber （Transwell） and in vitro angiogenesis by endothelial tube formation in Matrigel. RESULTS： Intraperitoneal injection of EGCG inhibited the growth of gastric cancer by 60.4%. MVD in tumor tissues treated with EGCG was markedly reduced. EGCG treatment reduced VEGF protein level in vitro and in vivo. Secretion and mRNA expression of VEGF in tumor cells were also suppressed by EGCG in a dose-dependent manner. This inhibitory effect was associated with reduced activation of Star3, but EGCG treatment did not change the total Star3 expression. EGCG also inhibited VEGF-induced endothelial cell proliferation, migration and tube formation. CONCLUSION： EGCG inhibits the growth of gastric cancer by reducing VEGF production and angiogenesis, and is a promising candidate for anti-angiogenic treatment of gastric cancer.

(-)-Epigallocatechin-3-gallate inhibits VEGF expression induced by IL-6 via Stat3 in gastric cancer

AIM: To demonstrate that (-)-Epigallocatechin-3-gallate (EGCG) inhibits vascular endothelial growth factor (VEGF) expression and angiogenesis induced by interleukin-6 (IL-6) via suppressing signal transducer and activator of transcription 3 (Stat3) activity in gastric cancer. METHODS: Human gastric cancer (AGS) cells were treated with IL-6 (50 ng/mL) and EGCG at different concentrations. VEGF, total Stat3 and activated Stat3 protein levels in the cell lyses were examined by Western blotting, VEGF protein level in the conditionedmedium was measured by enzyme-linked immunosorbent assay, and the level of VEGF mRNA was evaluated by reverse transcription polymerase chain reaction (RTPCR). Stat3 nuclear translocation was determined by Western blotting with nuclear extract, and Stat3-DNA binding activity was examined with Chromatin immunoprecipitation (ChIP) assay. IL-6 induced endothelial cell proliferation was measured with 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazoliumbromide assay, in vitro angiogenesis was determined with endothelial cell tube formation assay in Matrigel, and IL-6-induced angiogenesis in vitro was measured with Matrigel plug assay. RESULTS: There was a basal expression and secretion of VEGF in AGS cells. After stimulation with IL-6, VEGF expression was apparently up-regulated and a 2.4-fold increase was observed. VEGF secretion in the conditioned medium was also increased by 2.8 folds. When treated with EGCG, VEGF expression and secretion were dose-dependently decreased. IL-6 also increased VEGF mRNA expression by 3.1 folds. EGCG treatment suppressed VEGF mRNA expression in a dose-dependent manner. EGCG dose-dependently inhibited Stat3 activation induced by IL-6, but did not change the total Stat3 expression. When treated with EGCG or AG490, VEGF expressions were reduced to the level or an even lower level in the tumor cells not stimulated with IL-6. However, PD98059 and LY294002 did not change VEGF expression induced by IL-6. EGCG inhibited Stat3 nucleus translocation, and Stat3-DNA binding activity was also markedly decreased by EGCG. Furthermore, EGCG inhibited IL-6 induced vascular endothelial cell proliferation and tube formation in vitro and angiogenesis in vitro . CONCLUSION: EGCG inhibits IL-6-induced VEGF expression and angiogenesis via suppressing Stat3 activity in gastric cancer, which has provided a novel mechanistic insight into the anti-angiogenic activity of EGCG.

Green tea polyphenol epigallocatechin-3-gallate blocks PDGF-induced proliferation and migration of rat pancreatic stellate cells

AIM: To clarify the effects of epigallocatechin-3-gallate (EGCG) on the platelet-derived growth factor (PDGF)-BB-induced proliferation and migration of pancreatic stellate cells (PSCs). METHODS: PSCs were isolated from rat pancreas tissue and used in their culture-activated, myofibroblast-like phenotype. Cell proliferation was assessed by measuring the incorporation of 5-bromo-2'-deoxyuridine. Cell migration was assessed using modified Boyden chambers. Cyclin D1, p21waf1, and p27kip1 expression and phosphorylation of PDGF β-receptor, extracellular signal-regulated kinase, and Akt were examined by Western blotting. Activation of phospha-tidylinositol 3-kinase was examined by kinase assay using phosphatidylinositol as a substrate. Cell cycle was assessed by flow cytometry after staining with propidium iodide. RESULTS: EGCG at non-cytotoxic concentrations inhibited PDGF-induced proliferation and migration. This effect was associated with the inhibition of cell cycle progression beyond the G1 phase, decreased cyclin Dl and increased p27kip1 expression. EGCG inhibited tyrosine phosphorylation of PDGF p-receptor and downstream activation of extracellular signal-regulated kinase and phosphatidylinositol 3-kinase/ Akt pathways. CONCLUSION: EGCG inhibited PDGFBB-induced proliferation and migration of PSCs through the inhibition of PDGFmediated signaling pathways.

Apoptotic effect of Epigallocatechin-3-gallate on the human gastric cancer cell line MKN45 via activation of the mitochondrial pathway

To investigate whether Epigallocatechin-3-gallate （EGCG） can induce apoptosis of the gastric cancer cell line MKN45 and its apoptotic pathway.METHODS： To determine this, apoptotic rates of MKN45 cells after EGCG treatment with or without caspase-3 inhibitor were evaluated by Annexin V-FITC ＋ PI staining The influence of EGCG on the activity of caspase-3 in the MKN45 cells was determined by ELISA. By Rhodamine123 staining, the membrane potential change of the mitochondrion was also investigated, and mRNAs and protein expression of the bcl-2 family were analyzed by RT-PCR and Western blot.RESULTS： EGCG can induce apoptosis of MKN45 cells in time- and dose-dependent manner. Eight hours after EGCG treatment, the activity of caspase-3 in the MKN45 increased, especially 12 h after treatment. The mitochondrial membrane potential was significantly weakened 4 h after EGCG insult. The mRNA and protein expression levels of pro-apoptotic members, such as Bax, Bid and Bad, were upregulated gradually as treated time increased. Moreover, the mRNA and protein expression levels of anti-apoptotic members, such as Bcl-xL and Bcl-2, were inhibited. CONCLUSION： These data support that EGCG can induce apoptosis of the human gastric cancer cell line MKN45, and the effect is in a time- and dose-dependent manner. The apoptotic pathway triggered by EGCG in MKN45 is mitochondrial-dependent.

Cytotoxicity of epigallocatechin-3-gallate to LNCaP cellsin the presence of Cu^(2+)

Epigallocatechin-3-gallate (EGCG) has shown remarkably anti-cancer activity, with its bioactivity being related to reactive conditions, such as pH and metal ions. The present study investigated the degradation of EGCG and its effect on prostate cancer cell in the presence of Cu2+. EGCG was incubated with prostate cancer cells, LNCaP, pretreated with or without Cu2+.EGCG in F-12 medium was quantified using HPLC and the viability of cells was assessed by gel electrophoresis, flow cytometry,and electron microscope. The results of HPLC showed that EGCG degraded completely within 12 h in F-12 medium with or without Cu2+. Gel electrophoresis and flow cytometry did not detect apoptosis of LNCaP cells when they were incubated with EGCG. Electron microscopy examination revealed that EGCG-Cu2+ complex led to damage of cytoplasm membrane in LNCaP cells. It was speculated that not EGCG, but its oxide and complex with Cu2+, are the bioactive components responsible for its cytotoxicity to LNCaP prostate cancer cells.

Epigallocatechin-3-gallate Alleviates Cognitive Deficits in APP/PS1 Mice

Alzheimer's disease(AD)shows cognitive impairments in clinic,which is multifactorial with different etiopathogenic mechanisms such as A|3 deposition,neuroinflammation and neuronal dystrophy involved.Therefore,multi-targets drugs with neuroprotective,anti-amyloidogenic and anti-inflammatory properties will be effective in AD treatment.Epigallocatechin-3-gallate(EGCG)possesses a broad spectrum of pharmacological activities in the prevention and treatment of multiple neurodegenerative diseases.In the present study,we showed that oral administration of EGCG(50 mg/kg)for 4 months significantly attenuated the cognitive deficits in APP/PS1 transgenic mice,which served as AD model.Moreover,EGCG induced an improvement in dendritic integrity and expression levels of synaptic proteins in the brain of APP/PS 1 mice.And EGCG exerted obvious anti-inflammatory effects,which was manifested by alleviating microglia activation,decreasing pro-inflammatory cytokine(IL-β)and increasing anti-inflammatory cytokines(IL-10,IL-β).Furthermore,p-amyloid(AP)plaques were markedly reduced in the hippocampus of 6-month old APP/PS 1 mice after EGCG treatment.In conclusion,these findings indicate that EGCG improves AD-like cognitive impairments through neuroprotective,anti-amyloidogenic and anti-inflammatory effects,thus is a promising therapeutic can didate for AD.

Neuroprotective effect of epigallocatechin-3-gallate on hemisection-induced spinal cord injury in rats

Epigallocatechin-3-gallate （EGCG）, a naturally occurring compound in green tea, has been widely used as an antioxidant agent. In the present study, model rats with acute spinal cord injury were intraperitoneally injected with 25, 50, and 100 mg/kg EGCG, and spinal cord ultrastructure, oxidative stress reaction, inflammatory factors, and apoptosis-associated gene expression were observed. Results showed that EGCG attenuated neuronal and axonal injury 24 hours post injury. It also decreased serum intedeukin-113, tumor necrosis factor-a, and intercellular adhesion molecule-1 release, and decreased apoptosis-associated gene expression. Furthermore, it increased the level of the superoxide anion （O2-）, superoxide dismutase, and B-cell lymphoma/leukemia-2, and reduced malondialdehyde levels. Furthermore, it reduced the expression of the pro-apoptotic protein Bax. Noticeably, EGCG at the 100 mg/kg dosage exhibited similar effects as methylprednisolone sodium succinate, which has been frequently used for clinical acute spinal cord injury. The results demonstrated that EGCG can significantly inhibit inflammation, suppress oxidation, and reduce apoptosis in acute spinal cord injury.

Epigallocatechin-3-gallate treatment to promote neuroprotection and functional recovery after nervous system injury

Traumatic spinal cord injury （SCI） causes motor paralysis, sensory anesthesia and autonomic dysfunction below the le- sion site and additionally some SCI patients refer neuropathic pain together with these signs and symptoms. Clinical and experimental studies have revealed the main pathological changes of injured spinal cord implicated in all these signs and symptoms, including neuropathic pain. After few hours of traumatic SCI, it is usual to observe broken blood brain barrier with plasma and blood cells extravasation, cell necrosis, disruption of ascending and descending spinal cord pathways and increased potassium and glutamate. Glutamate contributes to excitotoxicity of neurons whereas potassium facilitates ectopic depolarization of survival neurons and activation of resident microglia.

Protective Effects of Epigallocatechin-3-gallate on Intestinal Ischemia Reperfusion Injury through Enhanced Activation of PI3K/Akt Pathway in Rats

Inflammation plays a critical role in intestinal ischemia reperfusion injury（IRI）. Epigallocatechin-3-gallate（EGCG） has been demonstrated to possess anti-inflammatory effect. This study examined the effect of EGCG on intestinal IRI and explored the possible mechanisms. Male Wistar rats were randomly divided into three groups： sham-operated group（Sham）, IRI control group（IRI） and IRI-EGCG group（EGCG）. Rats in IRI-EGCG group were administered dissolved EGCG in drinking water（0.4 mg/m L） for 14 days prior to IRI induction. A rat model of intestinal IRI was established by ligating the superior mesenteric artery（SMA） for 30 min, followed by reperfusion for 1 h. Intestinal histology, pro-inflammatory cytokines and mediators were examined and the effect of EGCG on PI3K/Akt signalling was assessed. EGCG significantly alleviated the pathological changes of the intestine and suppressed the IRI-induced up-regulation of TNF-α, IL-1 and IL-6 m RNA and protein expression in the serum and intestine. The mechanism might be that EGCG enhanced the activation of PI3K/Akt signalling pathway. In conclusion, the administration of EGCG can significantly mitigate the acute intestinal IRI in rats by enhancing the activation of PI3K/Akt signalling pathway to suppress inflammatory response and might be a promising alternative for the prevention or treatment of intestinal IRI in the clinical practice.

Epigallocatechin-3-gallate attenuates lipopolysaccharideinduced inflammation in human retinal endothelial cells

AIM:To investigate the mechanism underlying the anti-inflammatory effects of epigallocatechin-3-gallate(EGCG)in lipopolysaccharide(LPS)-stimulated human retinal endothelial cells(HRECs).METHODS:HRECspre-treatedwithEGCG(0-100μmol/L)were stimulated with LPS(250 ng/mL).Levels of tumor necrosis factor alpha(TNF-α),vascular endothelial growth factor(VEGF),monocyte chemotactic protein-1(MCP-1)and nitric oxide(NO)in the supernatants were determined by enzyme-linked immunosorbent assay(ELISA)and Griess assay.The protein expression of phosphorylated extracellular signal-regulated kinase(ERK)1/2 and p38 mitogen-activated protein kinases(p38)were determined by Western blot analysis.RESULTS:EGCG pre-treatment significantly inhibited the secretion of TNF-α,VEGF,MCP-1 and NO in LPSstimulated HRECs.Moreover,EGCG effectively attenuated LPS-induced activation and phosphorylation of ERK1/2 and p38 in HRECs in a dose-dependent manner.CONCLUSION:EGCG exhibited inhibitory effects on LPS-induced pro-inflammatory cytokines production by modulating ERK1/2 and p38 pathways in HRECs,suggesting EGCG as a potential candidate for antiinflammatory intervention.

Epigallocatechin-3-gallate suppresses transforming growth factor-beta signaling by interacting with the transforming growth factor-beta typeⅡreceptor

AIM: To investigate the(-)-epigallocatechin-3-gallate(EGCG) binding to transforming growth factor-β(TGF-β) type Ⅱ receptor(TGFRⅡ).METHODS: The expression of α-smooth muscle actin(α-SMA) was used as a marker for fibrotic change inhuman lung fibroblast MRC-5 cells. The α-SMA expression level was determined by western blotting and immunohistological analysis. We examined whether the anti-fibrotic effects of EGCG on MRC-5 cells was dependent on antioxidant mechanism by using edaravone and N-acetylcysteine(NAC). The suppression effects of EGCG on Smad2/3 activation were studied by confocal fluorescence microscopy. The binding of EGCG to recombinant TGFRⅡ protein was analyzed by immunoprecipitation and affinity chromatography.RESULTS: When MRC-5 cells were treated with TGF-β, EGCG decreased the expression of α-SMA in a dose dependent manner, whereas catechin did not influence the α-SMA expression in the cells. Except for EGCG, antioxidant compounds(e.g., edaravone and NAC) had no effects on the TGF-β-induced α-SMA expression. Nuclear localization of phosphorylated Smad2/3 was observed after TGF-β treatment; however, EGCG treatment attenuated the nuclear transportation of Smad2/3 in the presence or absence of TGF-β. After a TGFRⅡ expression vector was introduced into COS-7 cells, cell lysates were untreated or treated with EGCG or catechin. The immunoprecipitation experiments using the lysates showed that EGCG dose-dependently bound to TGFRⅡ and that catechin did not at all. Affinity chromatography study indicated that EGCG would bind to TGFRⅡ.CONCLUSION: Our results demonstrate that EGCG interacts with TGFRⅡ and inhibits the expression of α-SMA via the TGF-β-Smad2/3 pathway in human lung fibroblast MRC-5 cells.

The <i>in Vivo</i>Antioxidant Effects of (&minus;)-Epigallocatechin-3-Gallate Consumption in Healthy Postmenopausal Women Measured by Urinary Excretion of Secondary Lipid Peroxidation Products

The present study was carried out to determine whether the consumption of epigallocatechin (EGCG), the major bioactive green tea catechin, exerts a positive effect on lowering in vivo lipid peroxidation, a measure of oxidative stress, in healthy postmenopausal women. Urinary excretion of secondary lipid peroxidation products, a measure of in vivo lipid peroxidation, was determined in 40 participants randomly assigned to consume a green tea catechin extract (843.0 ± 44.0 mg EGCG/d) or placebo capsules for 12 months. Urine samples were analyzed for individual polar and nonpolar lipophilic aldehydes and related carbonyl compounds by high-performance liquid chromatography (HPLC) at the beginning and at the end of the 12-month intervention period. Results show that two nonpolar aldehydes, nonanal and decatrienal, were both 48% lower (p in vivo antioxidant activity exists with long-term EGCG consumption, which could slightly limit oxidative damage associated with lipid peroxidation and the onset and progression of chronic diseases.

EGCG Enhances TRAIL-mediated Apoptosis in Human Melanoma A375 Cell Line

Tumor necrosis factor-related apoptosis-inducing ligand （TRAIL） is a promising anti-cancer agent. Epigallocatechin-3-gallate （EGCG） is a polyphenolic constituent of green tea. In this study, inhibitory effect of combined use of EGCG and TRAIL on human melanoma A375 cells was examined and the possible mechanism investigated. The cells were divided into 4 groups： control group, EGCG group （EGCG： 10, 20 μg/mL）, TRAIL group （TRAIL： 25 ng/mL） and EGCG＋TRAIL group （combined group）. The growth inhibition was measured in the A375 cells treated with different concentrations of TRAIL （（25, 50, 75, 100, 125, 150 ng/mL） by MTT assay. The apoptosis was assessed by flow cytometry. The expressions of DR4 and DR5 were detected by flow cytometry and western blotting. The activities of caspase-8 and caspase-3 were determined by colorimetric assay. The results showed that TRAIL could dose-dependently inhibit the growth of A375 cells and the IC50 of TRAIL was 150 ng/mL. The apoptosis rate was 11.8% in the TRAIL group, 5%–7% in the EGCG group and 48.9%–59.1% in the combined group. Significant difference was found in the apoptosis rate between the combined group and the EGCG or TRAIL group （P〈0.05 for each）. The expression of DR4 instead of DR5 was significantly increased in the EGCG group. The activity of caspase-3 rather than caspase-8 was substantially enhanced in the EGCG group. These results suggest that EGCG is useful for the TRAIL-based treatment for melanoma.

Epigallocatechin-3-gallate affects the growth of LNCaP cells via membrane fluidity and distribution of cellular zinc

Objective:To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods: We examined changes in cellular morphology and membrane fluidity of LNCaP cells, distribution of cellular zinc, and the incorporated portion of EGCG after treatments with EGCG, Zn2+, and EGCG+Zn2+. Results: We observed an alteration in cellular morphology and a decrease in membrane fluidity of LNCaP cells after treatment with EGCG or Zn2+. The proportion of EGCG incorporated into liposomes treated with the mixture of EGCG and Zn2+ at the ratio of 1:1 was 90.57%, which was significantly higher than that treated with EGCG alone (30.33%). Electron spin resonance (ESR) studies and determination of fatty acids showed that the effects of EGCG on the membrane fluidity of LNCaP were decreased by Zn2+. EGCG accelerated the accumulation of zinc in the mitochondria and cytosol as observed by atomic absorption spectrometer. Conclusion: These results show that EGCG interacted with cell membrane, decreased the membrane fluidity of LNCaP cells, and accelerated zinc accumulation in the mitochondria and cytosol, which could be the mechanism by which EGCG inhibits proliferation of LNCaP cells. In addition, high concentrations of Zn2+ could attenuate the actions elicited by EGCG.

Study on Preparation Process of Effervescent Tablets Made from EGCG of Tea

[ Objectivel The study aimed to discuss the preparation process of Epigallocatechin-3-gallate （EGCG） effervescent tablets. [ Method] Various raw materials were dried for different time at 50℃, and then the sticking degree of EGCG effervescent tablets was reviewed. Hereafter, the formula of EGCG effervescent tablets was optimized by orthogonal test. [ Result] Effervescent tablets without sticking were smooth after being dried for 150 rain. The optimal formula of EGCG effervescent tablets was composed of 4% EGCG, 45% citric acid and sodium carbonate （Citric acid： Sodium carbonate = 1.6：1 ）, 20% lactose, 4% L-leucine, 4% sodium cyclamate and 23% orange powder. [Condusion] The prepared EGCG effervescent tablets without sticking has a good effervescence effect and taste.

Dietary Green Tea Extract and Antioxidants Improve Insulin Secretory Functions of Pancreatic β-Cells in Mild and Severe Experimental Rodent Model of Chronic Pancreatitis

Chronic pancreatitis (CP) is a progressive inflammatory disorder of the pancreas. It is predominantly idiopathic (with an unknown cause) in India and mostly due to alcohol in the West. Diabetes that occur secondary to chronic pancreatitis (T3c Diabetes) is often brittle, and is difficult to attain normoglycemia with conventional treatment requiring multiple doses of insulin. Mild and severe model of CP was induced in mice by repeated intraperitoneal injections of cerulein and L-arginine respectively with an intent to study islet dysfunction and develop therapeutic strategy in animal models of CP. Dietary intervention of epigallocatechin-3-gallate (EGCG) was tested in both the models of CP for its beneficial effects on insulin secretory functions. Pancreata collected upon euthanasia were used to study alterations in the morphology of pancreatic parenchyma and inflammation by staining with H&E and fibrotic changes by Masson’s trichrome and picrosirius staining. Insulin secretory functions of islets were evaluated to test the efficacy of the dietary intervention on β-cell functions. Intraperitoneal glucose tolerance test was performed to monitor the glucose homeostasis before and after the dietary intervention. Both the models resulted in CP with dispersed acini, inflammation and fibrosis. The loss of acini and extent of fibrosis was more in L-arginine model. 2-fold improvement in glucose-stimulated insulin secretory functions of islets was observed with 0.5% EGCG dietary intervention in cerulein model of CP and 1.6-fold in L-arginine model of CP. A further improvement in insulin secretion by 3.2-fold was observed with additional dietary supplements like N-acetyl cysteine, curcumin in combination with EGCG. Our results thus demonstrate and highlight the therapeutic potential of dietary green tea (EGCG) supplementation in reversing islet dysfunction and improving glucose homeostasis in experimental chronic pancreatitis in mice.

Epigallocatechin-3-gallate induces apoptosis, inhibits proliferation and decreases invasion of glioma cell

Epigallocatechin-3-gallate （EGCG）, a major polyphenol in green tea, has been considered a potential therapeutic and chemopreventive agent for cancer. Glioma is a malignant tumor with high mortality but effective therapy has not yet been developed. In this study, we found that EGCG induced apoptosis in U251 glioma cells via the laminin receptor （molecular weight 67kDa） in a time- and dose-dependent manner, decreased their invasiveness and inhibited their proliferation. The mitogen-activated protein kinase pathway was shown to be involved in glioma cell apoptosis and proliferation. Furthermore, the mRNA levels of matrix metalloproteinase （MMP）-2 and MMP-9 were reduced after EGCG treatment. These results suggest that EGCG has important therapeutic effects with low toxicity and side-effects, and could be used in cancer chemoprevention.

Green tea polyphenol, epigallocatechin-3-gallate, possesses the antiviral activity necessary to fight against the hepatitis B virus replication in vitro

Although several antiviral drugs and vaccines are available for use against hepatitis B virus （HBV）, hepatitis caused by HBV remains a major public health problem worldwide, which has not yet been resolved, and new anti-HBV drugs are in great demand. The present study was performed to investigate the anti-HBV activity of epigallocatechin- 3-gallate （EGCG）, a natural-origin compound, in HepG2 2.2.15 cells. The antiviral activity of EGCG was examined by detecting the levels of HBsAg and HBeAg in the supematant and extracellular HBV DNA. EGCG effectively suppressed the secretion of HBsAg and HBeAg from HepG2 2.2.15 cells in a dose- and time-dependent manner, and it showed stronger effects at the level of 0.11-0.44 pmol/ml （50-200 μg/ml） than lamivudine （3TC） at 0.87 μmol/ml （200 pg/ml）. EGCG also suppressed the amount of extracellular HBV DNA. The data indicated that EGCG possessed anti-HBV activity and suggested the potential of EGCG as an effective anti-HBV agent with low toxicity.