Effect of EGCG-based paste as intracanal dressing, in MMPs 2 and 9 expression in dog's periapical lesions

Abstract High expression of MMP-2 and MMP-9 in periapical lesions plays an important role in the degradation of the extracellular matrix. This study aimed to investigate the effect of epigallocatechin-3-gallate (EGCG)-based endodontic paste as an intracanal dressing on the expression of MMP-2 and MMP-9 in periapical lesions. Periapical lesions were experimentally induced in 35 mature beagle dog premolars randomly divided into healthy teeth, untreated periapical lesions, periapical lesions treated in a single session (control groups), and periapical lesions treated in two sessions with EGCG or calcium hydroxide-based pastes (experimental groups). After 120 days, specimens were obtained for histopathologic and immunofluorescence analyses to assess the expression of MMP-2 and MMP-9. The statistical analysis was performed using a p-value of 0.05. Endodontic treatment in two sessions using medication with EGCG and calcium hydroxide-based pastes provided similar repair of the apical and periapical tissues and neoformation of periodontal ligament fibers, cementum, and alveolar bone (p>0.05). The experimental groups treated in two sessions with both medications presented expression of MMP-2 and MMP-9 similar to that in healthy teeth (p>0.05), and significantly lower than teeth treated in a single session or untreated periapical lesions (p <0.001). Expression of MMP-2 and MMP-9 was observed in the cytoplasm of fibroblasts, osteoblasts, cementoblasts, cementocytes, and vascular endothelium. The use of EGCG-based endodontic paste reduced the expression of MMP-2 and MMP-9 and allowed repair of periapical lesions, similar to calcium hydroxide-based paste, and superior to treatment performed in a single session.

Resumo A alta expressão de MMP-2 e MMP-9 em lesões periapicais desempenha um papel importante na degradação da matriz extracelular. Este estudo teve como objetivo investigar o efeito de uma pasta à base de epigalocatequina-3-galato (EGCG) como curativo intracanal na expressão de MMP-2 e MMP-9 em lesões periapicais. Lesões periapicais foram induzidas experimentalmente em 35 pré-molares de cães da raça beagle, maduros, divididos aleatoriamente em dentes saudáveis, lesões periapicais não tratadas, lesões periapicais tratadas em uma única sessão e lesões periapicais tratadas em duas sessões com a pasta de EGCG ou pasta à base de hidróxido de cálcio. O operador monitorou os animais e realizou a eutanásia após 120 dias para análises histopatológicas e de imunofluorescência para avaliar a expressão de MMP-2 e MMP-9. A análise estatística foi realizada utilizando p=0,05. O tratamento endodôntico em duas sessões com pasta à base de EGCG e pasta à base de hidróxido de cálcio proporcionou níveis semelhantes de reparação dos tecidos apicais e periapicais e neoformação de fibras do ligamento periodontal, cemento e osso alveolar. Em ambos os grupos, a expressão de MMP-2 e MMP-9 foi mínima, sendo observada no citoplasma de fibroblastos, osteoblastos, cementoblastos, cementócitos e endotélio vascular. Em ambos os grupos tratados em duas sessões, a expressão de MMP-2 e MMP-9 foi semelhante à dos dentes hígidos e significativamente menor do que nas lesões periapicais tratadas em sessão única ou não tratadas (p < 0,001). O uso da pasta à base de EGCG reduziu a expressão de MMP-2 e MMP-9 e permitiu o reparo de lesões periapicais, semelhante à pasta à base de hidróxido de cálcio, e foi superior ao tratamento realizado em sessão única.

Research progress of epigallocatechin gallate in radiation protection / 中国辐射卫生

Epigallocatechin gallate (EGCG) is a major polyphenol component in green tea. EGCG has high free radical scavenging activity, radiation protection efficiency, and metal-chelating capacity due to its unique structure with hydroxyl groups. EGCG and its derivatives have been reported in various fields. This paper reviews the effects of EGCG, including radiation protection, heavy metal ion adsorption, and promotion of heavy metal ion excretion. EGCG has the potential to be used as an ideal radiation protection agent, heavy metal adsorbent, and even excretion promoting agent.

The potential inhibitory impact of curcumin, epigallocatechin gallate and their combinations on infectious bronchitis virus in vivo

Aims@#Infectious bronchitis virus (IBV) is a highly contagious, acute viral respiratory disease that mostly affects chickens. The poultry sector has suffered enormous losses as a result of IBV. Currently, live attenuated vaccines are routinely used to prevent and control IBV. However, due to the enormous genetic variety, vaccinations are becoming ineffective, with low cross-protection effects among vaccine serotypes. The present study aimed at investigating the possible antiviral effects of curcumin, epigallocatechin gallate (EGCG) and their mixtures against IBV in vivo.@*Methodology and results@#Curcumin, EGCG and their combinations were administered to infected and uninfected chicken groups and viral load titers were determined by real-time PCR. The clinical symptoms of both the negative and positive control groups were also compared. Finally, the trachea tissues of each group were examined histopathologically. According to our findings, the viral titer and the clinical signs dropped significantly during the pretreatment infection procedure. Curcumin, EGCG and their combinations also show significant antiviral activities.@*Conclusion, significance and impact of study@#This study clearly shown that natural compounds and their combinations, such as curcumin or/and ECGC can reduce viral pathogenicity in vivo, suggesting that they might have therapeutic implications in the poultry sector.

Study on the apoptosis of human retinal pigment epithelium cells induced by EGCG / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To investigate the effect of epigallocatechin gallate(EGCG)on the apoptosis of human retinal pigment epithelium(ARPE-19)cells and its mechanism. METHODS:The ARPE-19 cells were cultured in vitro and treated with 0,40,80 and 160 μg/mL EGCG, respectively. At the proposed time of treatment the morphological changes were detected by hoechst 33258 staining. The apoptosis rate was detected by flow cytometry. The expression of apoptosis-related factors B lymphocytoma-2 gene(bcl-2), BCL2-Associated X protein(Bax),caspase-3 and p53 were detected by quantitative RT-PCR and Western blotting.RESULTS: Hoechst 33258 staining showed that the ARPE-19 cells with the increase of EGCG drug concentration, the number of apoptotic cells gradually increased and the apoptotic bodies were observed. Flow cytometry showed that the apoptosis rate increased gradually with the increase of EGCG drug concentration. The apoptosis rates at 40, 80 and 160 μg/mL were 4.95%±0.071%, 11.75%±0.075% and 21.25%±0.919% respectively, which was significantly different compared with the control group(2.8%±1.556%)(P<0.01), presented with a drug concentration-dependent. The results of quantitative PCR and Western blotting showed that EGCG could significantly up-regulate the expression of apoptosis-promoting factors Bax, caspase-3 and the mRNA and protein expression of p53, and down-regulate the apoptosis-inhibiting factor bcl-2, all of these showed concentration-dependent effects.CONCLUSION:EGCG can obviously induce the apoptosis of ARPE-19 cells. The mechanism is related with the inhibition of bcl-2 and increase the expression of Bax, caspase-3 and p53.

The effect and mechanism of epigallocatechol gallate combined with trastuzumab on the proliferation of HER2 overexpressing breast cancer cells / 药学实践杂志

Objective To study the effect and mechanism of epigallocatechol gallate (EGCG) combined with trastuzu-mab on the proliferation of human epidermal growth factor receptor 2 (HER2) overexpressing breast cancer cells. Methods Trastuzumab was expressed and purified. The cell proliferation of HER2 overexpressing breast cancer cells BT474 and SK-BR-3 treated with trastuzumab, EGCG, or trastuzumab plus EGCG was evaluated by CCK8 assay. The effects of EGCG and trastuzumab on the expression of HER2, epidermal growth factor receptor (EGFR), mitogen-activated protein kinase (MAPK), protein kinase B (Akt), and their phosphorylated proteins in BT474 breast cancer cells were detected by Western blot. Results The results of cell proliferation assay indicated that EGCG and trastuzumab, alone or in combination, effectively inhibited the proliferation of BT-474 and SK-BR-3 cells. And within a certain concentration range, EGCG and trastuzumab showed a synergistic proliferation inhibitory effect on HER2 overexpressing breast cancer cells. Consistent with these results, Western blot results showed that trastuzumab and EGCG, alone or in combination significantly reduced the phosphorylation levels of Akt, MAPK, EGFR, and HER2 in BT474 cells. Moreover, the inhibition effect of EGCG plus trastuzumab was significantly more potent than either EGCG or trastuzumab. Conclusion EGCG and trastuzumab could synergistically inhibit the proliferation of HER2 overexpressing breast cancer cells, which may be related to the regulation of Akt and MAPK signaling pathways.

EGCG and ECG induce apoptosis and decrease autophagy via the AMPK/mTOR and PI3K/AKT/mTOR pathway in human melanoma cells / 中国天然药物

Catechins have been proven to exert antitumor effects in different kinds of cancers. However, the underlying mechanisms have not been completely clarified yet. This study aimed to assess the effects and mechanisms of (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) on human melanoma skin A375 cells. Results showed that EGCG and ECG inhibited the proliferation of A375 cells and ECG showed better inhibitory effect. Flow cytometry analysis had shown that EGCG and ECG induced apoptosis and led to cell cycle arrest. EGCG and ECG decreased Bcl-2 expression and upregulated Caspase-3 protein level, indicating the development of apoptosis. Furthermore, EGCG and ECG could decreased mitochondrial membrane potential of A375 cells. In addition, the expression of Beclin-1, LC3 and Sirt3 were downregulated at protein levels, which known to be associated with autophagy. After autophagy was increased by rapamycin, the apoptotic trend was not change, indicating that apoptosis and autophagy are independent. Mechanistically, EGCG and ECG treatments decreased phosphorylated-AMPK (p-AMPK) and increased the ratios of p-PI3K, p-AKT and p-mTOR in melanoma cells. Conclusively, EGCG and ECG induced apoptosis via mitochondrial signaling pathway, downregulated autophagy through modulating the AMPK/mTOR and PI3K/AKT/mTOR signaling pathway. It indicated that EGCG and ECG may be utilized in human melanoma treatment.

Potential effect of EGCG on the anti-tumor efficacy of metformin in melanoma cells / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Metformin, a first-line drug for type 2 diabetes mellitus, has been recognized as a potential anti-tumor agent in recent years. Epigallocatechin-3-gallate (EGCG), as the dominant catechin in green tea, is another promising adjuvant agent for tumor prevention. In the present work, the potential effect of EGCG on the anti-tumor efficacy of metformin in a mouse melanoma cell line (B16F10) was investigated. Results indicated that EGCG and metformin exhibited a synergistic effect on cell viability, migration, and proliferation, as well as signal transducer and activator of transcription 3/nuclear factor-κB (STAT3/NF-κB) pathway signaling and the production of inflammation cytokines. Meanwhile, the combination showed an antagonistic effect on cell apoptosis and oxidative stress levels. The combination of EGCG and metformin also differentially affected the nucleus (synergism) and cytoplasm (antagonism) of B16F10 cells. Our findings provide new insight into the potential effects of EGCG on the anti-tumor efficacy of metformin in melanoma cells.

A smart dual-drug nanosystem based on co-assembly of plant and food-derived natural products for synergistic HCC immunotherapy

Nanotechnology has emerged as an ideal approach for achieving the efficient chemo agent delivery. However, the potential toxicity and unclear internal metabolism of most nano-carriers was still a major obstacle for the clinical application. Herein, a novel "core‒shell" co-assembly carrier-free nanosystem was constructed based on natural sources of ursolic acid (UA) and polyphenol (EGCG) with the EpCAM-aptamer modification for hepatocellular carcinoma (HCC) synergistic treatment. As the nature products derived from food-plant, UA and EGCG had good anticancer activities and low toxicity. With the simple and "green" method, the nanodrugs had the advantages of good stability, pH-responsive and strong penetration of tumor tissues, which was expected to increase tumor cellular uptake, long circulation and effectively avoid the potential defects of traditional carriers. The nanocomplex exhibited the low cytotoxicity in the normal cells

The use of epigallocatechin gallate prevents white spot lesions during orthodontic treatment with fixed appliances / 中国组织工程研究

BACKGROUND: Plenty of studies have already proved the effective usage of epigallocatechin gallate (EGCG) in clinical treatment. However, no current research has focused on the application of EGCG in preventing white spot lesions (WSLs) during orthodontics treatment with fixed appliances. OBJECTIVE: To study the value of EGCG in the prevention of WSLs during orthodontic treatment with fixed appliances. METHODS: In total 50 patients undergoing orthodontic treatment with fixed appliances were carefully screened and enrolled. Split-mouth design was adopted: the right side of teeth received experimental adhesive (1 g/L EGCG + Adper™ Single Bond 2); the left side of teeth acted as control. All the other clinical procedures and materials used were same. The enamel demineralization index (EDI) and the WSLs prevalence of targeted teeth (16, 11, 46, 26, 31, and 36) were detected at 3, 6, and 12 months during the treatment, and the percentage of bracket bonding failure was calculated for each group. The study protocol was implemented in line with the relevant ethical requirements of Liuzhou People’s Hospital. Patients and their guardians were fully informed of the whole trial procedures. RESULTS AND CONCLUSION: In this trial, the percentage of bracket bonding failure was significantly different between the EGCG group and control group (P > 0.05). After 3 months of treatment, the values of WSLs and EDI had no significant difference between the EGCG group and control group (P > 0.05). However, after 6 months and 12 months treatment, the EGCG group manifested significantly lower WSL and EDI values than the control group (P < 0.05). Therefore, addition of the adhesive containing 1 g/L EGCG has a considerable effect in preventing enamel demineralization and the occurrence of WSLs without influencing the enamel bonding strength, and it has a long-time effect which deserves the clinical expansion.

Effects of Epigallocatechin-3-Gallate (EGCG) on Cell Cycle Distribution and DNA Integrity of K562 Cells, A Human Chronic Myeloid Leukemia(Kesan Epigallocatechin-3-Gallate (EGCG) ke atas Distribusi Kitaran Sel dan Integriti DNA Sel K562, Leukemia Myeloid Kronik Manusia) / Jurnal Sains Kesihatan Malaysia

@#Epigallocatechin-3-gallate (EGCG) is a naturally derived compound from green tea with high antioxidant activity and various anti-cancer properties. EGCG has been widely investigated worldwide. However, effects of EGCG on cell cycle of K562 have not been clearly stated elsewhere. This study was conducted with the aim to investigate the antiproliferative effect of EGCG on K562 human leukemic cells and its underlying mechanism of action on the cells. MTT assay was conducted to determine cytotoxicity effect of EGCG on the K562 cells. Meanwhile, cell cycle analysis and DNA damage on the cells were determined by Flow cytometry and Comet assay respectively. K562 cells were treated with EGCG at concentrations ranging from 0 to 100µg/ml for 48 hours. The results showed that EGCG effectively decreased the percentage of cell viability in a dose dependent manner. The IC10, IC25 and IC50 of EGCG on K562 cell lines were 5 ± 2.44 µg/mL, 10 ± 5.93 µg/mL and 50 ± 1.93 µg/mL, respectively. In cell cycle assay, EGCG has shown no significant effect (p>0.05) on the cell cycle of K562 cell line as compared to negative control, whereas Imatinib mesylate as the positive control showed cell cycle arrest at S phase in this cell line. Hence, EGCG can be verified as a non-cell cycle specific compound. In addition, EGCG was found to cause a significant increase (p<0.05) in tail moment value and percentage of DNA tail in K562 cell line, suggesting DNA damage as an early signal of EGCG induced cell cytotoxicity. In conclusion, by decreasing the cell viability and inducing DNA damage, EGCG showed promising potential as an alternative treatment for leukemia through non-cell cycle specific pathway and further investigation on other mechanisms of action of EGCG on the cells is recommended.

The epigallocatechin gallate derivative Y reverses drug resistance mediated by the ABCB1 transporter both and

Previously, we reported that Y, a new epigallocatechin gallate derivative, is efficacious in reversing doxorubicin (DOX)--mediated resistance in hepatocellular carcinoma BEL-7404/DOX cells. In this study, we evaluated the efficacy of Y in reversing drug resistance both and by determining its effect on the adenosine triphosphate-binding cassette protein B1 transporter (ABCB1 or P-glycoprotein, P-gp). Our results showed that Y significantly sensitized cells overexpressing the ABCB1 transporter to anticancer drugs that are ABCB1 substrates. Y significantly stimulated the adenosine triphosphatase activity of ABCB1. Furthermore, Y exhibited a higher docking score as compared with epigallocatechin gallate inside the transmembrane domain of ABCB1. In addition, in the nude mouse tumor xenograft model, Y (110 mg/kg, intragastric administration), in combination with doxorubicin (2 mg/kg, intraperitoneal injection), significantly inhibited the growth of BEL-7404/DOX cell xenograft tumors, compared to equivalent epigallocatechin gallate. In conclusion, Y significantly reversed ABCB1-mediated multidrug resistance and its mechanisms of action may result from its competitive inhibition of the ABCB1 drug efflux function.

Analysis of B cell subsets in rhumatoid arthritis patients and the effect of epigallocatechingallate on B cell subsets / 上海交通大学学报（医学版）

Objective:To explore the characteristics of B cell subsets in rheumatoid arthritis (RA) patients and the regulation of epigallocatechingallate (EGCG) on B cell subsets in RA patients. Methods:Twenty-nine age- and sex-matched RA patients and 29 healthy controls were selected, and the difference of B cell subsets in peripheral blood between the two groups was analyzed by paired t-test. According to the value of disease activity score in 28 joints (DAS28), RA patients were divided into active group (2.6 ≤ DAS28 0.05). There was no significant difference in the numbers and the proportions of total B cells and B cell subsets (except CD19+ IL-10+ Breg) between 10 RA patients of active group and 19 RA patients of highly active group (P>0.05). There was no significant difference in the number and the proportion of CD19+ IL-10+ Breg in lymphocytes between 6 RA patients of active group and 12 RA patients of highly active group (P>0.05). The proportion of total B cells was weakly positively correlated with IgG type rheumatoid factor (r=0.308). EGCG could significantly increase the proportion of CD19+ IL-10+ Breg (P0.05). Conclusion:B cells may play an auxiliary role in the development of RA. The number of CD19+ IL-10+ Breg in RA patients increases as a feedback. EGCG can promote Breg proliferation and suppress BAFF-R mRNA expression.

Clinical Information on Green Tea Extract Used for Weight Loss

BACKGROUND: Green tea extracts are approved as nonprescription drug and available as health functional foods, health foods, and beverages. Clinical information on the products is lacking. METHODS: Information about the products on green tea nonprescription drugs was obtained from the website of the Korea Pharmaceutical Information Center. The Naver, i.e., a top ranking online search portal, was used for compiling the list of the health functional food products using key words of ‘green tea catechin’ on August 23, 2018. The recommended daily dosages of catechins were calculated as 30% of the total dried mass of green tea and about 50% of the catechins were considered as epigallocatechin gallate (EGCG). RESULTS: A total of two types of nonprescription drugs containing green tea powder or extracts, nine health functional food products, and three types of health foods were found. The regulatory requirements of the EGCG exceeding 800 mg were reported to be associated with adverse effects of elevated liver enzyme. If consumers take several green tea products concurrently, such as nonprescription drugs with health functional foods or health foods, it could exceed the recommended amount of EGCG. CONCLUSION: The concurrent use of green tea products as nonprescription drugs, health functional foods, and healthy foods may lead to an increased exposure to EGCG. Pharmacists should be aware the availability of various types of green tea products and the potential risk of liver toxicity due to excessive consumption of EGCG.

Molecular mechanism of epigallocatechin gallate-mediated anti-HBV replication effect / 中华实验和临床病毒学杂志

Objective@#To elucidate the mechanism of epigallocatechin gallate (EGCG) mediated anti-HBV effect.@*Methods@#The CCK-8 kit was used to test cell viability in response to EGCG treatment. For HBV DNA replication assay, purified HBV DNA was analyzed by real-time PCR assay. Western blotting was used to confirm HNF4α expression in response to EGCG or siRNA treatment.@*Results@#Our result showed that, EGCG treatment significantly decreasee HBV DNA level both in vivo and in vitro without affecting cell viability. Curiously, we found that EGCG treatment downregulated HNF4α expression. Considering that HNF4α could restrain HBV replication, we knocked down HNF4α in HepG2.2.15 cells and found that the response of HBV replication to EGCG decreased obviously.@*Conclusions@#The above result suggest that HNF4α could be an important intracellular factor in EGCG mediated anti-HBV signaling pathway.

Protective effects of Epigallocatechin gallate on liver ischemia reperfusion injury in rats / 中华肝胆外科杂志

Objective To investigate the protective roles of Epigallocatechin gallate (EGCG) on liver ischemia reperfusion injury (IRI) in rats.Methods 30 healthy male SD rats were selected and equally and randomly divided into 3 groups.Sham group,IRI group and IRI-EGCG group were established to construct 70％ liver IRI rat model.Drinking water with 0.4 mg/ml EGCG was administered for 2 weeks before the experiment in IRI-EGCG group.HE staining was performed to evaluate the injury.Transaminases in serum were investigated to assess liver injury.p-p85 and p-AKT was detected by Western-blot assay.qPCR was carried out to study the mRNA expression of TNF-α,IL-6 and IL-1β in liver tissue.The secretion of TNF-α,IL-6 and IL-1 β in serum was examined with ELISA assay.Results EGCG pretreatment reduced ASTand ALT in serum [AST:(550.0 ±66.5) IU/L vs.(220.0 ±63.5) IU/L;ALT:(376.0 ± 25.7) IU/L vs.(158.0 ± 33.1) IU/L,all P ＜ 0.05] and mitigated liver tissue damage.p-p85 and p-AKT increased due to liver IRI,and IRI-EGCG group showed higher expression of p85 and AKT.The proinflammatory cytokines of TNF-α,IL-6 and IL-1 β exhibited a relatively lower mRNA expression in IRI-EGCG group comparing with IRI group.IRI-EGCG group also revealed a decreased secretion of TNF-α,IL-6 and IL-1β in serum [TNF-α:(398.0±33.4) ng/Lvs.(211.0±23.6) ng/L;IL-6:(341.0±27.3) ng/L vs.(187.0±19.6) ng/L;IL-1β:(486.0±43.7) ng/L vs.(352.0±31.5) ng/L;allP＜0.05].Conclusion EGCG pretreatment can enhance IRI-induced activation of PI3K/AKT signaling and reduce the release of proinflammatory cytokines to exert liver protective effects.

Research advances of(-)epigallo-catechingallate in cancer clinical trials / 中国肿瘤临床

Epigallo-catechingallate(EGCG),the most abundant polyphenol and important active ingredient in green tea,is widely studied in cancer prevention and treatment.It has demonstrated various anti-cancer activities in vitro and in vivo,including induction of apoptosis, as well as inhibition of tumor cell invasion,migration,and angiogenesis.EGCG has been in the clinical stage of drug development with some findings currently available.In the present review,we systematically summarize the research advances of EGCG in cancer treatment through collection of global clinical trials and related results and discuss its safety,research efficacy,and critical challenges.

Histomorphometric evaluation of bone healing capacity of epigallocatechin-3-gallate-loaded β-TCP bone substitute in rabbit calvarial defects / 대한치과재료학회지

This study investigated the effect of epigallocatechin-3-gallate (EGCG)-loaded microporous β-tricalcium phosphate (β-TCP) bone substitute in the bone healing of rabbit calvarial defects. New bone formation induced by β-TCP incorporating two different dose of EGCG [1 mg EGCG/200 mg β-TCP (TCP-1), 10 mg EGCG/200 mg β-TCP (TCP-10)] was compared with unloaded β-TCP (TCP-0). Calvarial defects 8 mm diameter created in 14 adult male New Zealand White rabbits were filled with three types of bone substitutes. The amount of newly formed bone was evaluated histomorphometrically at 4 and 8 weeks after implantation. The TCP-1 group exhibited increased bone healing capacity and numerous blood vessel formation compared with the other two groups. New bone formation was observed in the cental area of TCP-1 filled defects at 8 weeks. Histomorphometric analysis revealed significantly greater newly formed bone area in the TCP-1 group when compared with unloaded TCP-0 (p < 0.05 at 4 and 8 weeks) and 10 mg EGCG-loaded TCP-10 groups (p < 0.05 at 8 weeks). No difference was observed in new bone area between TCP-0 and TCP-10 groups. These results suggest that local delivery of 1 mg EGCG to β-TCP bone substitute by simple adsorption promotes bone regeneration in the healing of rabbit calvarial osseous defect and higher EGCG dose (in this study, 10 mg per defect) does not exert any positive effect on bone healing capacity of β-TCP. Thus, local delivery of EGCG to β-TCP bone substitute seems to be an effective approach for the treatment of osseous defects.

Effect of epigallocatechin-3-gallate on oxidative stress and inflammation in 3T3-L1 adipocytes / 上海交通大学学报（医学版）

Objective • To explore the effect of epigallocatechin-3-gallate (EGCG) on oxidative stress and inflammation in 3T3-L1 adipocytes, and provide a theoretical basis for EGCG to prevent obesity and related chronic diseases. Methods • 3T3-L1 preadipocytes were differentiated to mature adipocytes by in vitro cell culture. The cells were divided into blank control group, and 1, 10 and 50 μg/mL EGCG groups. After 24 hour treatment, intracellular oxidative stress indicators glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) levels in the cells were measured. The levels of inflammatory indexes interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) were tested by ELISA and realtime PCR, while the expression of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was tested by realtime PCR. Results • Compared with the control group, GSH and SOD levels in 3T3-L1 adipocytes increased in a dose-dependent manner after treatment of EGCG (both P<0.05), while MDA level in 3T3-L1 adipocytes decreased dose-dependently after treatment of EGCG (P<0.05). IL-6, MCP-1 and TNF-α levels in 3T3-L1 adipocytes supernatant declined significantly in a dose-dependent manner after treatment of 1, 10 and 50 μg/mL EGCG (all P<0.05). The expression levels of IL-6, MCP-1 and TNF-α in 3T3-L1 adipocytes were decreased in a dose-dependent manner after 24 h treatment of different concentrations of EGCG. Nrf2 and HO-1 mRNA levels in 3T3-L1 adipocytes increased significantly in a dose-dependent manner after treatment of 10 and 50 μg/mL EGCG (both P<0.05). Conclusion • EGCG plays an antioxidation and anti-inflammatory effects in 3T3-L1 adipocytes, which may be related to up-regulation of Nrf2/HO-1.

Anti-inflammatory properties of oolong tea (Camellia sinensis) ethanol extract and epigallocatechin gallate in LPS-induced RAW 264.7 cells

Objective To evaluate the anti-inflammatory activity of oolong tea ethanol extract (OTEE) and epigallocatechin gallate (EGCG) on lipopolysaccharide-induced murine macrophage cell line (RAW 264.7). Methods A cytotoxic assay using MTS tetrazolium was conducted to find a nontoxic level of OTEE and EGCG toward RAW 264.7 cells. Interleukins (IL-6, IL-1β), tumor necrosis factor-α (TNF-α), and cyclooxigenase-2 (COX-2) levels were measured by ELISA, and nitric oxide (NO) levels measured by a nitrate/nitrite colorimetric assay to determine the inhibition activity of OTEE and EGCG. Results Lipopolysaccharide induction increases NO, COX-2, IL-6, IL-1β, and TNF-α levels compared with the untreated cell (negative control). The positive control, lipopolysaccharide-induced RAW 264.7 without treatments showed the highest level of all pro-inflammatory cytokines and modulators tested in this study. The positive control was used as standard to obtain OTEE and EGCG inhibition activity toward NO, COX-2, IL-6, IL-1β, and TNF-α. OTEE had a higher inhibition activity toward NO, COX-2, IL-6, and IL-1β than EGCG; the reverse was seen for TNF-α. However, both OTEE and EGCG suppressed production of NO, COX-2, IL-6, IL-1β, and TNF-α. Conclusions OTEE and EGCG have the potential for use as anti-inflammatory drugs, which is shown by their ability to reduce the production of NO, COX-2, IL-6, IL-1β, and TNF-α in active macrophages.

Protective effect of epigallocatechin-3-gallate on hypoxia/reoxygenation injury in cardiac myocytes and its mechanism / 中国药理学通报

Aim To observe the protective effect of epigallocatechin-3-gallate (EGCG) on hypoxia/reoxygenation (H/R) injury of cardiac myocytes and its mechanisms.Methods H9c2 cardiac myocytes were cultured in vitro and randomly divided into five groups:normal group(N group),H/R group,EGCG low dose group (L group),EGCG medium dose group (M group),and EGCG high dose group(H group).The cardiomyocyte H/R injury model was established and EGCG was pretreated.Cell survival rate was tested by CCK-8 method.The cell apoptotic rate was detected using Annexin V-FITC/PI double staining.The contents of total antioxidant capacity(T-AOC) and tumor necrosis factor α(TNF-α) in cell culture medium were tested according to the kit instructions.The protein expression of Akt and p-Akt was observed using Western blot,while the gene expressions of PI3K,Akt,caspase3 were detected by using fluorescence quantitative PCR method.Results Compared with model group,EGCG increased cell survival rate and reduced the apoptosis after H/R injury.Meanwhile,pretreatment EGCG improved the activity of T-AOC,reduced the level of TNF-α,up-regulated the expression of PI3K,Akt and p-Akt,and down-regulated the expression of caspase3.Conclusion EGCG reduces apoptosis and protects cardiac myocytes by influencing PI3K/Akt signal path