Cancer is one of the leading causes of death worldwide.Commonly used cancer treatments,including chemotherapy and radiation therapy,often have side effects and a complete cure is sometimes impossible.Therefore,prevent...Cancer is one of the leading causes of death worldwide.Commonly used cancer treatments,including chemotherapy and radiation therapy,often have side effects and a complete cure is sometimes impossible.Therefore,prevention,suppression,and/or delaying the onset of the disease are important.The onset of gastroenterological cancers is closely associated with an individual's lifestyle.Thus,changing lifestyle,specifically the consumption of fruits and vegetables,can help to protect against the development of gastroenterological cancers.In particular,naturally occurring bioactive compounds,including curcumin,resveratrol,isothiocyanates,(-)-epigallocatechin gallate and sulforaphane,are regarded as promising chemopreventive agents.Hence,regular consumption of these natural bioactive compounds found in foods can contribute to prevention,suppression,and/or delay of gastroenterological cancer development.In this review,we will summarize natural phytochemicals possessing potential antioxidant and/or anti-inflammatory and anti-carcinogenic activities,which are exerted by regulating or targeting specific molecules against gastroenterological cancers,including esophageal,gastric and colon cancers.展开更多
AIM:To analyze the antiviral mechanism of Epigallocatechin gallate(EGCG)against hepatitis B virus(HBV) replication.METHODS:In this research,the HBV-replicating cell line HepG2.117 was used to investigate the antiviral...AIM:To analyze the antiviral mechanism of Epigallocatechin gallate(EGCG)against hepatitis B virus(HBV) replication.METHODS:In this research,the HBV-replicating cell line HepG2.117 was used to investigate the antiviral mechanism of EGCG.Cytotoxicity of EGCG was analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Hepatitis B virus e antigen(HBeAg)and hepatitis B virus surface antigen(HBsAg)in the supernatant were detected by enzyme-linked immunosorbent assay.Precore mRNA and pregenomic RNA(pgRNA) levels were determined by semi-quantitative reverse transcription polymerase chain reaction(PCR)assay.The effect of EGCG on HBV core promoter activity was measured by dual luciferase reporter assay.HBV covalently closed circular DNA and replicative intermediates of DNA were quantified by real-time PCR assay.RESULTS:When HepG2.117 cells were grown in the presence of EGCG,the expression of HBeAg was suppressed,however,the expression of HBsAg was not affected.HBV precore mRNA level was also downregulated by EGCG,while the transcription of precore mRNA was not impaired.The synthesis of both HBV covalently closed circular DNA and replicative intermediates of DNA were reduced by EGCG treatment to a similar extent,however,HBV pgRNA transcripted from chromosome-integrated HBV genome was not affected by EGCG treatment,indicating that EGCG targets only replicative intermediates of DNA synthesis.CONCLUSION:In HepG2.117 cells,EGCG inhibits HBV replication by impairing HBV replicative intermediates of DNA synthesis and such inhibition results in reduced production of HBV covalently closed circular DNA.展开更多
Many phytochemicals show promise in cancer prevention and treatment, but their low aqueous solubility, poor stability, unfavorable bioavailability, and low target specificity make administering them at therapeutic dos...Many phytochemicals show promise in cancer prevention and treatment, but their low aqueous solubility, poor stability, unfavorable bioavailability, and low target specificity make administering them at therapeutic doses unrealistic. This is particularly true for(-)-epigallocatechin gallate, curcumin, quercetin, resveratrol, and genistein. There is an increasing interest in developing novel delivery strategies for these natural products. Liposomes, micelles, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers and poly(lactide-co-glycolide) nanoparticles are biocompatible and biodegradable nanoparticles. Those nanoparticles can increase the stability and solubility of phytochemicals, exhibit a sustained release property, enhance their absorption and bioavailability, protect them from premature enzymatic degradation or metabolism, prolong their circulation time, improve their target specificity to cancer cells or tumors via passive or targeted delivery, lower toxicity or side-effects to normal cells or tissues through preventing them from prematurely interacting with the biological environment, and enhance anti-cancer activities. Nanotechnology opens a door for developing phytochemical-loaded nanoparticles for prevention and treatment of cancer.展开更多
The quality marker is a brand new concept not only for the quality assessment and control of TCMs but also for other herbal medicine systems which shares similar features of multiple components.It is also worth to men...The quality marker is a brand new concept not only for the quality assessment and control of TCMs but also for other herbal medicine systems which shares similar features of multiple components.It is also worth to mention that integration of traditional Chinese medicinal theory with such modern science as natural products chemistry,chromatographic analysis,network pharmacology,systems biology,is essential for the determination and validation of reasonable,scientific,and practical quality markers.展开更多
Objective: To investigate the effect of Red Peony 801 (propyl gallate,PrG) on cyclooxygenase (COX) activity in murine peritoneal macrophages. Methods: A screening model for COX inhibitors in vitro based on murine peri...Objective: To investigate the effect of Red Peony 801 (propyl gallate,PrG) on cyclooxygenase (COX) activity in murine peritoneal macrophages. Methods: A screening model for COX inhibitors in vitro based on murine peritoneal macrophages was used. COX-1 activity was reflected by the level of 6-ketoprostaglandin F1α(6-keto-PGF1α) in supernatants of cultured macrophages which were stimulated with calcium ionophore A23187 for a short-term, while COX-2 activity was reflected by the level of prostaglandin E2 (PGE2) in supernatants of cultured macrophages which were stimulated with lipopolysaccharide (LPS) for a long-term. Results: PrG did not affect A23187-induced, COX-1-derived 6-keto-PGF1α synthesis at the concentrations of 1×10-5, 5×10-6 mol/L (P>0.05), but enhanced 6-keto-PGF1α synthesis at the concentrations of 1×10-6, 5×10-7, 1×10-7 mol/L (P<0.01) in vitro, and showed a good dose-dependent manner. It inhibited LPS-induced, COX-2-derived PGE2 synthesis at the concentrations of 1×10-5,1×10-6 mol/L (P< 0. 05). Conclusion: Within the range of 1×10-5 to 1×10-7 mol/L, PrG activated COX-1 at lower concentrations and inhibited COX-2 at higher concentrations in murine peritoneal macrophages.展开更多
AIM To investigate the effect of epigallocatechin gallate(EGCG) on structural changes of gut microbiota in colorectal carcinogenesis.METHODS An azoxymethane(AOM)/dextran sodium sulfate(DSS)-induced colitis mouse model...AIM To investigate the effect of epigallocatechin gallate(EGCG) on structural changes of gut microbiota in colorectal carcinogenesis.METHODS An azoxymethane(AOM)/dextran sodium sulfate(DSS)-induced colitis mouse model was established. Fortytwo female FVB/N mice were randomly divided into the following three groups: group 1(10 mice, negative control) was treated with vehicle, group 2(16 mice, positive control) was treated with AOM plus vehicle, and group 3(16 mice, EG) was treated with AOM plus EGCG. For aberrant crypt foci(ACF) evaluation, the colons were rapidly took out after sacrifice, rinsed with saline, opened longitudinally, laid flat on a polystyrene board, and fixed with 10% buffered formaldehyde solution before being stained with 0.2% methylene blue in saline. For tumor evaluation, the colon was macroscopically inspected and photographed, then the total number of tumors was enumerated and tumor size measured. For histological examination, the fixed tissues were paraffin-embedded and sectioned at 5 mm thickness. Microbial genomic DNA was extracted from fecal and intestinal content samples using a commercial kit. The V4 hypervariable regions of 16 S r RNA were PCR-amplified with the barcoded fusion primers. Using the best hit classification option, the sequences from each sample were aligned to the RDP 16 S r RNA training set to classify the taxonomic abundance in QIIME. Statistical analyses were then performed.RESULTS Treatment of mice with 1% EGCG caused a significant decrease in the mean number of ACF per mouse, when compared with the model mice treated with AOM/DSS(5.38 ± 4.24 vs 13.13 ± 3.02, P < 0.01). Compared with the positive control group, 1% EGCG treatment dependently decreased tumor load per mouse by 85%(33.96 ± 6.10 vs 2.96 ± 2.86, respectively, P < 0.01). All revealed that EGCG could inhibit colon carcinogenesis by decreasing the number of precancerous lesions as well as solid tumors, with reduced tumor load and delayed histological progression of CRC. During the cancerization, the divers展开更多
AIM:(-)-Epigallocatechin-3-gallate(EGCG), a major compound of tea polyphenols, exhibited antitumor activity in previous studies. In these studies, EGCG usually inhibits EGFR, and impairs the ERK1/2 phosphorylation in ...AIM:(-)-Epigallocatechin-3-gallate(EGCG), a major compound of tea polyphenols, exhibited antitumor activity in previous studies. In these studies, EGCG usually inhibits EGFR, and impairs the ERK1/2 phosphorylation in tumor cells. The aim was to clarify the mechanism of ERK1/2 activation induced by EGCG. METHODS: Jurkat and 293 T cells were treated with EGCG in different culture conditions. Western Blotting(WB) was employed to analyze ERK1/2 and MEK phosphorylation. Cetuximab and FR180204 were used to inhibit cell signaling. The stability of EGCG was assessed by HPLC. The concentration of hydrogen peroxide generated by the auto-oxidation of EGCG was determined by photocolorimetric analysis. RESULTS: Activation of ERK1/2 was observed to be both time- and dose-dependent. Stimulation of cell signaling was dependent on MEK activity, but independent of EGFR activity. Unexpectedly, EGCG was depleted within one hour of incubation under traditional culture conditions. Auto-oxidation of EGCG generated a high level of hydrogen peroxide in the medium. Addition of catalase and SOD to the acidic medium inhibited the oxidation of EGCG. However, this particular condition also prevented the phosphorylation of ERK1/2. The generation of ROS by hydrogen peroxide may also induce ERK1/2 activation in Jurkat cells. CONCLUSION: ERK1/2 phosphorylation was caused by auto-oxidation of EGCG. Traditional culture conditions were determined to be inappropriate for EGCG research.展开更多
To investigate the anti-α_(s1)-casein allergy mechanism of two tea-derived polyphenols,epigallocatechin(EGC)and epigallocatechin gallate(EGCG),BALB/c mice were sensitized and challenged withα_(s1)-casein and nutriti...To investigate the anti-α_(s1)-casein allergy mechanism of two tea-derived polyphenols,epigallocatechin(EGC)and epigallocatechin gallate(EGCG),BALB/c mice were sensitized and challenged withα_(s1)-casein and nutritional intervention was given by EGC and EGCG during the sensitization provocation phase.The main evaluation indexes used were levels of mast cell proteases,histamine,and specific antibody immunoglobulin E(IgE),as well as cytokine secretion and pathological observation.The results showed that both EGC and EGCG significantly reduced levels of mast cell protease,histamine,specific IgE antibodies,and Th2 cytokines in allergic mice.The histopathology results showed that both EGC and EGCG markedly reduced the degree of lesions in the intestine,thymus,spleen,and lung.The conclusions from this study can provide a theoretical basis for the mechanism by which tea polyphenols regulate food allergens.展开更多
Systematic inflammatory response after spinal cord injury （SCI） is one of the factors leading to lesion development and a profound degree of functional loss. Anti-inflammatory compounds, such as curcumin and epigall...Systematic inflammatory response after spinal cord injury （SCI） is one of the factors leading to lesion development and a profound degree of functional loss. Anti-inflammatory compounds, such as curcumin and epigallocatechin gallate （EGCG） are known for their neuroprotective effects. In this study, we investigated the effect of combined therapy of curcumin and EGCG in a rat model of acute SCI induced by balloon compression. Immediately after SCI, rats received curcumin, EGCG, curcumin ＋ EGCG or saline [daily intraperitoneal doses （curcumin, 6 mg/kg; EGCG 17 mg/kg）] and weekly intramuscular doses （curcumin,60 mg/kg; EGCG 17 mg/kg）] for 28 days. Rats were evaluated using behavioral tests （the Basso, Beattie, and Bresnahan （BBB） open-field locomotor test, flat beam test）. Spinal cord tissue was analyzed using histological methods （Luxol Blue-cresyl violet staining） and mmunohistochemistry （anti-glial fibrillary acidic protein, anti-growth associated protein 43）. Cytokine levels （interleukin-1β, interleukin-4, interleukin-2,interleukin-6, macrophage inflammatory protein 1-alpha, and RANTES） were measured using Luminex assay. Quantitative polymerase chain reaction was performed to determine the relative expression of genes （Sort1, Fgf2, Irf5, Mrc1, Olig2, Casp3, Gap43, Gfap, Vegf, NfκB, Cntf） related to regenerative processes in injured spinal cord. We found that all treatments displayed significant behavioral recovery, with no obvious synergistic effect after combined therapy of curcumin and ECGC. Curcumin and EGCG alone or in combination increased axonal sprouting, decreased glial scar formation, and altered the levels of macrophage inflammatory protein 1-alpha, interleukin-1β, interleukin-4 and interleukin-6 cytokines. These results imply that although the expected synergistic response of this combined therapy was less obvious, aspects of tissue regeneration and immune responses in severe SCI were evident.展开更多
Objective:To investigate the effects of Propyl Gallate(PrG) on cellular adhesion between human umbilical vein endothelial cells(HUVEC) and polymorphonuclear leukocytes(PMN) as well as the expression of intercellular a...Objective:To investigate the effects of Propyl Gallate(PrG) on cellular adhesion between human umbilical vein endothelial cells(HUVEC) and polymorphonuclear leukocytes(PMN) as well as the expression of intercellular adhesion molecule-1(ICAM-1,CD54) and E-selectin(CD62E) on the VEC surface.Methods: A human VEC inflammation model was induced by tumor necrosis factor alpha(TNF-α).VECs were preincubated with varying concentrations of PrG(0.001-5 mmol/L) or 1‰DMSO(v:v) or 10 mmol/L acetylsalicylic acid(ASA) for ...展开更多
Flavonoids,secondary plant products which could be essential for normal physiology in humans and animals,may be the vitamins of the next century.Flavonoids belong to the polyphenols and possess antioxidative,anti-infl...Flavonoids,secondary plant products which could be essential for normal physiology in humans and animals,may be the vitamins of the next century.Flavonoids belong to the polyphenols and possess antioxidative,anti-inflammatory,antimutagenic and anticarcinogenic properties.Among the various flavonoid species,tea flavonoids such as apigenin (from camomile) and epigallocatechin gallate (EGCG from green tea) can be used for the prevention of intestinal neoplasia,especially for adenoma and cancer prevention in the gastrointestinal tract.Numerous experimental studies with molecular and biological end points support the therapeutic efficacy of bioflavonoids.Clinical studies with cohorts and case-control trials suggest that flavonoids are effective in tertiary bioprevention but,as yet,there are no controlled randomized clinical trials.Flavonoids can inhibit inflammatory pathways and could be useful for chronic inflammatory bowel diseases.Flavonoid deficiency syndromes could be therapeutic targets in the future.展开更多
AIM：To compare the potential protective effects of epigallocatechin gallate（EGCG） and ellagic acid（EA） in an experimental cataract model.●METHODS：Twenty-eight Spraque-Dawley rat pups were assigned into four gro...AIM：To compare the potential protective effects of epigallocatechin gallate（EGCG） and ellagic acid（EA） in an experimental cataract model.●METHODS：Twenty-eight Spraque-Dawley rat pups were assigned into four groups.All the rats,except for those in the control group,were injected subcutaneously sodium selenite to induce experimental cataract on the postpartum ninth day,and between 10 th and 14 th days.Rats in the sham,EGCG,and EA groups were intraperitoneally administered 50 mg/（kg·d） saline solution,50 mg/（kg·d） EGCG and 200 mg/（kg·d） EA,respectively.The reduced glutathione（GSH） and malondialdehyde（MDA） levels,total antioxidant status（TAS） and total oxidant status（TOS） in lens supernatants were measured.RESULTS：The mean cataract gradings in EGCG and EA groups were found to be significantly lower than that in sham group（P〈0.001）.The mean GSH levels and TASs in EGCG and EA groups were significantly higher than that in sham group while mean MDA levels and TOSs in EGCG and EA groups were significantly lower than that in the sham group（P〈0.001）.CONCLUSION：EGCG and EA have protective effects on cataract development via the inhibition of oxidative stress.展开更多
The fresh leaves of China green tea, Camellia sinensis, were collected from Fuyang, Zhejiang Province, China, in April. The tea polyphenols was extracted by four different methods （homogenized with distilled water at...The fresh leaves of China green tea, Camellia sinensis, were collected from Fuyang, Zhejiang Province, China, in April. The tea polyphenols was extracted by four different methods （homogenized with distilled water at room temperature, homogenized with 0.3% citric acid （w/v） at room temperature, 5- min boiling and homogenized with distilled water at room temperature, homogenized with 85℃ distilled water）, and after preserving at room temperature, the change of the Epigallocatechin gallate （EGCG） contents of the extracts was investigated. Results indicated that the EGCG content of homogenate extracted with 85℃ distilled water was the highest before the extract was preserved, followed by that of the extract homogenized with 0.3% citric acid at room temperature. During preservation, EGCG content changed obviously. The EGCG contents of homogenates extracted with distilled water at room temperature and 85℃ distilled water declined quickly and separately reduced to 21.52% and 54.6% of their initial contents after preservation for 12 h. The EGCG contents extracted by 0.3% citric acid （w/v） solvent at room temperature and 5- min boiling/homogenized with distilled water at room temperature declined relatively slowly ,and separately reduced to 76.9% and 85.16% of their initial contents after preservation for 12 h. It was also found that the citric acid can prevent the degradation of EGCG and the extract solution color is light green展开更多
The near-infrared[NIR]emitting wavelength-tunable Cr^(3+)-doped barium gallate[BGO:Cr]persistent luminescence[PersL]phosphors with enhanced luminescence were reported.The emission wavelength of the BGO:Cr PersL phosph...The near-infrared[NIR]emitting wavelength-tunable Cr^(3+)-doped barium gallate[BGO:Cr]persistent luminescence[PersL]phosphors with enhanced luminescence were reported.The emission wavelength of the BGO:Cr PersL phosphors was adjusted from 715 to 739 nm by varying the amount of Cr^(3+) and the ratio of Ga:Ba.Meanwhile,the luminescence intensity and afterglow of the BG0:Cr PersL phosphors were enhanced.BGO:Cr PersL phosphors exhibited UV excitation,LED light restimulation,PersL for more than 6 days,and excellent capability for information storage,which was expected to promote the development of cheap and wavelength-tunable PersL materials for practical applications.展开更多
Bulk LaO-GaO-ZrO(LGZ)glass and Tm/Ybco-doped LGZ glasses were synthesized successfully using containerless technique.Raman spectra result reveals that the matrix sample possesses the low maximum phonon energy of~642 c...Bulk LaO-GaO-ZrO(LGZ)glass and Tm/Ybco-doped LGZ glasses were synthesized successfully using containerless technique.Raman spectra result reveals that the matrix sample possesses the low maximum phonon energy of~642 cm.The glasses show good compatibility between large Abbe numbers(>31)and high refractive indices(n>1.93).Moreover,transmittance measurements reflect that the glasses have high infrared transmittance of-81.9%,small OHabsorption coefficient and long mid-infrared cut-off wavelengths(-7.5μm).The surface morphology of host glass was characterized by scanning electron microscopy(SEM)micrograph and energy dispersive spectroscopy(EDS)tests reflect that the doped compositions are distributed into the matrix glass homogeneously.The results of thermal analysis show that the glasses have good thermal properties(T>769℃).Excited by 980 am laser,an intense 1810 am fluorescence is obtained originating from the transition:~3 E→~3 Hof Tmion,accompanied by upconversion emission.It can be observed that 1810 nm fluorescence has the highest intensity at 1 mol%YbOand owns broad full width at half-maximum(>245 nm),the luminescence intensity of~3 F→~3 Htransition increases with rising temperature from 300 to 550 K.Furthermore,the value of energy transfer efficiency shows that Ybcan transfer energy to Tmeffectively.By fitting the attenuation curves,the lifetimes of 1810 and 474 nm emission can be acquired.展开更多
Objective:Our aim was to test the hypothesis that fatty acid synthase(FASN)expression contributes to radioresistance of nasopharyngeal carcinoma(NPC)cells and that inhibiting FASN enhances radiosensitivity.Methods:Tar...Objective:Our aim was to test the hypothesis that fatty acid synthase(FASN)expression contributes to radioresistance of nasopharyngeal carcinoma(NPC)cells and that inhibiting FASN enhances radiosensitivity.Methods:Targeting FASN using epigallocatechin gallate(EGCG)or RNA interference in NPC cell lines that overexpress endogenous FASN was performed to determine their effects on cellular response to radiationin vitro using MTT and colony formation assays,andin vivo using xenograft animal models.Western blot,immunohistochemistry,real-time PCR arrays,and real-time RT-PCR were used to determine the relationship between FASN and frizzled class receptor 10(FZD10)expression.FZD10 knockdown and overexpression were used to determine its role in mediating FASN function in cellular response to radiation.Immunohistochemical staining was used to determine FASN and FZD10 expressions in human NPC tissues,followed by analysis of their association with the overall survival of patients.Results:FASN knockdown or inhibition significantly enhanced radiosensitivity of NPC cells,bothin vitro andin vivo.There was a positive association between FASN and FZD10 expression in NPC cell lines grown as monolayers or xenografts,as well as human tissues.FASN knockdown reduced FZD10 expression,and rescue of FZD10 expression abolished FASN knockdown-induced enhancement of radiosensitivity.FASN and FZD10 were both negatively associated with overall survival of NPC patients.Conclusions:FASN contributes to radioresistance,possiblyvia FZD10 in NPC cells.Both FZD10 and FASN expressions were associated with poor outcomes of NPC patients.EGCG may sensitize radioresistance by inhibiting FASN and may possibly be developed as a radiosensitizer for better treatment of NPCs.展开更多
基金Supported by Grants from the Next-Generation BioGreen 21 Program (Plant Molecular Breeding Center,No. PJ008187),Rural Development Administrationthe Leap Research Program(2010-0029233)World Class University Program (GrantR31-2008-00-10056-0) through the National Research Foundation of Korea funded by the Ministry of Education,Science and Technology,South Korea
文摘Cancer is one of the leading causes of death worldwide.Commonly used cancer treatments,including chemotherapy and radiation therapy,often have side effects and a complete cure is sometimes impossible.Therefore,prevention,suppression,and/or delaying the onset of the disease are important.The onset of gastroenterological cancers is closely associated with an individual's lifestyle.Thus,changing lifestyle,specifically the consumption of fruits and vegetables,can help to protect against the development of gastroenterological cancers.In particular,naturally occurring bioactive compounds,including curcumin,resveratrol,isothiocyanates,(-)-epigallocatechin gallate and sulforaphane,are regarded as promising chemopreventive agents.Hence,regular consumption of these natural bioactive compounds found in foods can contribute to prevention,suppression,and/or delay of gastroenterological cancer development.In this review,we will summarize natural phytochemicals possessing potential antioxidant and/or anti-inflammatory and anti-carcinogenic activities,which are exerted by regulating or targeting specific molecules against gastroenterological cancers,including esophageal,gastric and colon cancers.
基金Supported by National Technology and Science Key Project (2008ZX10002-010)the Important National Science and Technology Specific Projects(2009ZX09301-014)
文摘AIM:To analyze the antiviral mechanism of Epigallocatechin gallate(EGCG)against hepatitis B virus(HBV) replication.METHODS:In this research,the HBV-replicating cell line HepG2.117 was used to investigate the antiviral mechanism of EGCG.Cytotoxicity of EGCG was analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Hepatitis B virus e antigen(HBeAg)and hepatitis B virus surface antigen(HBsAg)in the supernatant were detected by enzyme-linked immunosorbent assay.Precore mRNA and pregenomic RNA(pgRNA) levels were determined by semi-quantitative reverse transcription polymerase chain reaction(PCR)assay.The effect of EGCG on HBV core promoter activity was measured by dual luciferase reporter assay.HBV covalently closed circular DNA and replicative intermediates of DNA were quantified by real-time PCR assay.RESULTS:When HepG2.117 cells were grown in the presence of EGCG,the expression of HBeAg was suppressed,however,the expression of HBsAg was not affected.HBV precore mRNA level was also downregulated by EGCG,while the transcription of precore mRNA was not impaired.The synthesis of both HBV covalently closed circular DNA and replicative intermediates of DNA were reduced by EGCG treatment to a similar extent,however,HBV pgRNA transcripted from chromosome-integrated HBV genome was not affected by EGCG treatment,indicating that EGCG targets only replicative intermediates of DNA synthesis.CONCLUSION:In HepG2.117 cells,EGCG inhibits HBV replication by impairing HBV replicative intermediates of DNA synthesis and such inhibition results in reduced production of HBV covalently closed circular DNA.
基金supported by grant from the National Center for Complementary&Integrative Health(Nos.R15AT007013 and R15AT008733)
文摘Many phytochemicals show promise in cancer prevention and treatment, but their low aqueous solubility, poor stability, unfavorable bioavailability, and low target specificity make administering them at therapeutic doses unrealistic. This is particularly true for(-)-epigallocatechin gallate, curcumin, quercetin, resveratrol, and genistein. There is an increasing interest in developing novel delivery strategies for these natural products. Liposomes, micelles, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers and poly(lactide-co-glycolide) nanoparticles are biocompatible and biodegradable nanoparticles. Those nanoparticles can increase the stability and solubility of phytochemicals, exhibit a sustained release property, enhance their absorption and bioavailability, protect them from premature enzymatic degradation or metabolism, prolong their circulation time, improve their target specificity to cancer cells or tumors via passive or targeted delivery, lower toxicity or side-effects to normal cells or tissues through preventing them from prematurely interacting with the biological environment, and enhance anti-cancer activities. Nanotechnology opens a door for developing phytochemical-loaded nanoparticles for prevention and treatment of cancer.
文摘The quality marker is a brand new concept not only for the quality assessment and control of TCMs but also for other herbal medicine systems which shares similar features of multiple components.It is also worth to mention that integration of traditional Chinese medicinal theory with such modern science as natural products chemistry,chromatographic analysis,network pharmacology,systems biology,is essential for the determination and validation of reasonable,scientific,and practical quality markers.
文摘Objective: To investigate the effect of Red Peony 801 (propyl gallate,PrG) on cyclooxygenase (COX) activity in murine peritoneal macrophages. Methods: A screening model for COX inhibitors in vitro based on murine peritoneal macrophages was used. COX-1 activity was reflected by the level of 6-ketoprostaglandin F1α(6-keto-PGF1α) in supernatants of cultured macrophages which were stimulated with calcium ionophore A23187 for a short-term, while COX-2 activity was reflected by the level of prostaglandin E2 (PGE2) in supernatants of cultured macrophages which were stimulated with lipopolysaccharide (LPS) for a long-term. Results: PrG did not affect A23187-induced, COX-1-derived 6-keto-PGF1α synthesis at the concentrations of 1×10-5, 5×10-6 mol/L (P>0.05), but enhanced 6-keto-PGF1α synthesis at the concentrations of 1×10-6, 5×10-7, 1×10-7 mol/L (P<0.01) in vitro, and showed a good dose-dependent manner. It inhibited LPS-induced, COX-2-derived PGE2 synthesis at the concentrations of 1×10-5,1×10-6 mol/L (P< 0. 05). Conclusion: Within the range of 1×10-5 to 1×10-7 mol/L, PrG activated COX-1 at lower concentrations and inhibited COX-2 at higher concentrations in murine peritoneal macrophages.
基金Supported by Natural Science Foundation of Minhang District of Shanghai,No.2012MHZ001
文摘AIM To investigate the effect of epigallocatechin gallate(EGCG) on structural changes of gut microbiota in colorectal carcinogenesis.METHODS An azoxymethane(AOM)/dextran sodium sulfate(DSS)-induced colitis mouse model was established. Fortytwo female FVB/N mice were randomly divided into the following three groups: group 1(10 mice, negative control) was treated with vehicle, group 2(16 mice, positive control) was treated with AOM plus vehicle, and group 3(16 mice, EG) was treated with AOM plus EGCG. For aberrant crypt foci(ACF) evaluation, the colons were rapidly took out after sacrifice, rinsed with saline, opened longitudinally, laid flat on a polystyrene board, and fixed with 10% buffered formaldehyde solution before being stained with 0.2% methylene blue in saline. For tumor evaluation, the colon was macroscopically inspected and photographed, then the total number of tumors was enumerated and tumor size measured. For histological examination, the fixed tissues were paraffin-embedded and sectioned at 5 mm thickness. Microbial genomic DNA was extracted from fecal and intestinal content samples using a commercial kit. The V4 hypervariable regions of 16 S r RNA were PCR-amplified with the barcoded fusion primers. Using the best hit classification option, the sequences from each sample were aligned to the RDP 16 S r RNA training set to classify the taxonomic abundance in QIIME. Statistical analyses were then performed.RESULTS Treatment of mice with 1% EGCG caused a significant decrease in the mean number of ACF per mouse, when compared with the model mice treated with AOM/DSS(5.38 ± 4.24 vs 13.13 ± 3.02, P < 0.01). Compared with the positive control group, 1% EGCG treatment dependently decreased tumor load per mouse by 85%(33.96 ± 6.10 vs 2.96 ± 2.86, respectively, P < 0.01). All revealed that EGCG could inhibit colon carcinogenesis by decreasing the number of precancerous lesions as well as solid tumors, with reduced tumor load and delayed histological progression of CRC. During the cancerization, the divers
基金supported by the Natural Science Foundation of Yunnan Province,China(No.2012FB151)
文摘AIM:(-)-Epigallocatechin-3-gallate(EGCG), a major compound of tea polyphenols, exhibited antitumor activity in previous studies. In these studies, EGCG usually inhibits EGFR, and impairs the ERK1/2 phosphorylation in tumor cells. The aim was to clarify the mechanism of ERK1/2 activation induced by EGCG. METHODS: Jurkat and 293 T cells were treated with EGCG in different culture conditions. Western Blotting(WB) was employed to analyze ERK1/2 and MEK phosphorylation. Cetuximab and FR180204 were used to inhibit cell signaling. The stability of EGCG was assessed by HPLC. The concentration of hydrogen peroxide generated by the auto-oxidation of EGCG was determined by photocolorimetric analysis. RESULTS: Activation of ERK1/2 was observed to be both time- and dose-dependent. Stimulation of cell signaling was dependent on MEK activity, but independent of EGFR activity. Unexpectedly, EGCG was depleted within one hour of incubation under traditional culture conditions. Auto-oxidation of EGCG generated a high level of hydrogen peroxide in the medium. Addition of catalase and SOD to the acidic medium inhibited the oxidation of EGCG. However, this particular condition also prevented the phosphorylation of ERK1/2. The generation of ROS by hydrogen peroxide may also induce ERK1/2 activation in Jurkat cells. CONCLUSION: ERK1/2 phosphorylation was caused by auto-oxidation of EGCG. Traditional culture conditions were determined to be inappropriate for EGCG research.
基金supported by the National Key Research and Development Program of China(2019YFC1605002)the National Natural Science Foundation of China(31872886)。
文摘To investigate the anti-α_(s1)-casein allergy mechanism of two tea-derived polyphenols,epigallocatechin(EGC)and epigallocatechin gallate(EGCG),BALB/c mice were sensitized and challenged withα_(s1)-casein and nutritional intervention was given by EGC and EGCG during the sensitization provocation phase.The main evaluation indexes used were levels of mast cell proteases,histamine,and specific antibody immunoglobulin E(IgE),as well as cytokine secretion and pathological observation.The results showed that both EGC and EGCG significantly reduced levels of mast cell protease,histamine,specific IgE antibodies,and Th2 cytokines in allergic mice.The histopathology results showed that both EGC and EGCG markedly reduced the degree of lesions in the intestine,thymus,spleen,and lung.The conclusions from this study can provide a theoretical basis for the mechanism by which tea polyphenols regulate food allergens.
基金supported by the grant GACR(Grant Agency of the Czech Republic)P304/12/G069the Ministry of Education,Youth and Sports under the project“Centre of Reconstructive Neuroscience”,registration number CZ.02.1.01/0.0./0.0/15_003/0000419project Inter Action LTAUSA17120
文摘Systematic inflammatory response after spinal cord injury （SCI） is one of the factors leading to lesion development and a profound degree of functional loss. Anti-inflammatory compounds, such as curcumin and epigallocatechin gallate （EGCG） are known for their neuroprotective effects. In this study, we investigated the effect of combined therapy of curcumin and EGCG in a rat model of acute SCI induced by balloon compression. Immediately after SCI, rats received curcumin, EGCG, curcumin ＋ EGCG or saline [daily intraperitoneal doses （curcumin, 6 mg/kg; EGCG 17 mg/kg）] and weekly intramuscular doses （curcumin,60 mg/kg; EGCG 17 mg/kg）] for 28 days. Rats were evaluated using behavioral tests （the Basso, Beattie, and Bresnahan （BBB） open-field locomotor test, flat beam test）. Spinal cord tissue was analyzed using histological methods （Luxol Blue-cresyl violet staining） and mmunohistochemistry （anti-glial fibrillary acidic protein, anti-growth associated protein 43）. Cytokine levels （interleukin-1β, interleukin-4, interleukin-2,interleukin-6, macrophage inflammatory protein 1-alpha, and RANTES） were measured using Luminex assay. Quantitative polymerase chain reaction was performed to determine the relative expression of genes （Sort1, Fgf2, Irf5, Mrc1, Olig2, Casp3, Gap43, Gfap, Vegf, NfκB, Cntf） related to regenerative processes in injured spinal cord. We found that all treatments displayed significant behavioral recovery, with no obvious synergistic effect after combined therapy of curcumin and ECGC. Curcumin and EGCG alone or in combination increased axonal sprouting, decreased glial scar formation, and altered the levels of macrophage inflammatory protein 1-alpha, interleukin-1β, interleukin-4 and interleukin-6 cytokines. These results imply that although the expected synergistic response of this combined therapy was less obvious, aspects of tissue regeneration and immune responses in severe SCI were evident.
基金Supported by the National Natural Science Foundation of China(No.90409021)
文摘Objective:To investigate the effects of Propyl Gallate(PrG) on cellular adhesion between human umbilical vein endothelial cells(HUVEC) and polymorphonuclear leukocytes(PMN) as well as the expression of intercellular adhesion molecule-1(ICAM-1,CD54) and E-selectin(CD62E) on the VEC surface.Methods: A human VEC inflammation model was induced by tumor necrosis factor alpha(TNF-α).VECs were preincubated with varying concentrations of PrG(0.001-5 mmol/L) or 1‰DMSO(v:v) or 10 mmol/L acetylsalicylic acid(ASA) for ...
基金Supported by A Grant of the University of Dresden from the Department of Clinical Pharmacology
文摘Flavonoids,secondary plant products which could be essential for normal physiology in humans and animals,may be the vitamins of the next century.Flavonoids belong to the polyphenols and possess antioxidative,anti-inflammatory,antimutagenic and anticarcinogenic properties.Among the various flavonoid species,tea flavonoids such as apigenin (from camomile) and epigallocatechin gallate (EGCG from green tea) can be used for the prevention of intestinal neoplasia,especially for adenoma and cancer prevention in the gastrointestinal tract.Numerous experimental studies with molecular and biological end points support the therapeutic efficacy of bioflavonoids.Clinical studies with cohorts and case-control trials suggest that flavonoids are effective in tertiary bioprevention but,as yet,there are no controlled randomized clinical trials.Flavonoids can inhibit inflammatory pathways and could be useful for chronic inflammatory bowel diseases.Flavonoid deficiency syndromes could be therapeutic targets in the future.
基金Funded by an unrestricted grant from Firat University Scientific Research Unit
文摘AIM：To compare the potential protective effects of epigallocatechin gallate（EGCG） and ellagic acid（EA） in an experimental cataract model.●METHODS：Twenty-eight Spraque-Dawley rat pups were assigned into four groups.All the rats,except for those in the control group,were injected subcutaneously sodium selenite to induce experimental cataract on the postpartum ninth day,and between 10 th and 14 th days.Rats in the sham,EGCG,and EA groups were intraperitoneally administered 50 mg/（kg·d） saline solution,50 mg/（kg·d） EGCG and 200 mg/（kg·d） EA,respectively.The reduced glutathione（GSH） and malondialdehyde（MDA） levels,total antioxidant status（TAS） and total oxidant status（TOS） in lens supernatants were measured.RESULTS：The mean cataract gradings in EGCG and EA groups were found to be significantly lower than that in sham group（P〈0.001）.The mean GSH levels and TASs in EGCG and EA groups were significantly higher than that in sham group while mean MDA levels and TOSs in EGCG and EA groups were significantly lower than that in the sham group（P〈0.001）.CONCLUSION：EGCG and EA have protective effects on cataract development via the inhibition of oxidative stress.
文摘The fresh leaves of China green tea, Camellia sinensis, were collected from Fuyang, Zhejiang Province, China, in April. The tea polyphenols was extracted by four different methods （homogenized with distilled water at room temperature, homogenized with 0.3% citric acid （w/v） at room temperature, 5- min boiling and homogenized with distilled water at room temperature, homogenized with 85℃ distilled water）, and after preserving at room temperature, the change of the Epigallocatechin gallate （EGCG） contents of the extracts was investigated. Results indicated that the EGCG content of homogenate extracted with 85℃ distilled water was the highest before the extract was preserved, followed by that of the extract homogenized with 0.3% citric acid at room temperature. During preservation, EGCG content changed obviously. The EGCG contents of homogenates extracted with distilled water at room temperature and 85℃ distilled water declined quickly and separately reduced to 21.52% and 54.6% of their initial contents after preservation for 12 h. The EGCG contents extracted by 0.3% citric acid （w/v） solvent at room temperature and 5- min boiling/homogenized with distilled water at room temperature declined relatively slowly ,and separately reduced to 76.9% and 85.16% of their initial contents after preservation for 12 h. It was also found that the citric acid can prevent the degradation of EGCG and the extract solution color is light green
基金The work was supported by the National Natural Science Foundation of China(NSFC)(No.21867014)Science and Technology Talents Training Project of Tianshan Youth Program of Xinjiang Uygur Autonomous Region(No.2017Q086).
文摘The near-infrared[NIR]emitting wavelength-tunable Cr^(3+)-doped barium gallate[BGO:Cr]persistent luminescence[PersL]phosphors with enhanced luminescence were reported.The emission wavelength of the BGO:Cr PersL phosphors was adjusted from 715 to 739 nm by varying the amount of Cr^(3+) and the ratio of Ga:Ba.Meanwhile,the luminescence intensity and afterglow of the BG0:Cr PersL phosphors were enhanced.BGO:Cr PersL phosphors exhibited UV excitation,LED light restimulation,PersL for more than 6 days,and excellent capability for information storage,which was expected to promote the development of cheap and wavelength-tunable PersL materials for practical applications.
基金Project supported by the Youth Innovation Promotion Association,the Chinese Academy of Sciences(2020256)the Key Equipment Research Program,CAS(YJKYYQ20190008)+2 种基金the Science and Technology Committee of Shanghai(19142200400,20QA1410300)the National Natural Science Foundation of China(51602330,51472263)the Science and Technology Innovation Action Project of Science and Technology Committee of Shanghai(20511107400,19DZ1100703,20511107404)。
文摘Bulk LaO-GaO-ZrO(LGZ)glass and Tm/Ybco-doped LGZ glasses were synthesized successfully using containerless technique.Raman spectra result reveals that the matrix sample possesses the low maximum phonon energy of~642 cm.The glasses show good compatibility between large Abbe numbers(>31)and high refractive indices(n>1.93).Moreover,transmittance measurements reflect that the glasses have high infrared transmittance of-81.9%,small OHabsorption coefficient and long mid-infrared cut-off wavelengths(-7.5μm).The surface morphology of host glass was characterized by scanning electron microscopy(SEM)micrograph and energy dispersive spectroscopy(EDS)tests reflect that the doped compositions are distributed into the matrix glass homogeneously.The results of thermal analysis show that the glasses have good thermal properties(T>769℃).Excited by 980 am laser,an intense 1810 am fluorescence is obtained originating from the transition:~3 E→~3 Hof Tmion,accompanied by upconversion emission.It can be observed that 1810 nm fluorescence has the highest intensity at 1 mol%YbOand owns broad full width at half-maximum(>245 nm),the luminescence intensity of~3 F→~3 Htransition increases with rising temperature from 300 to 550 K.Furthermore,the value of energy transfer efficiency shows that Ybcan transfer energy to Tmeffectively.By fitting the attenuation curves,the lifetimes of 1810 and 474 nm emission can be acquired.
基金This work was supported by grants from the National Natural Science Foundation of China(Grant Nos.81572588,81872147)Shantou University Medical College Clinical Trial Uplift Program(Grant No.201423)+4 种基金the Medical Scientific Research Foundation of Guangdong Province,China(Grant No.B2018222)the Traditional Chinese Medicine Research Project from Traditional Chinese Medicine Bureau of Guangdong Province(Grant No.20191182)the Youth Research Grant from Shantou University Medical College Cancer Hospital(Grant No.2018A001,2018A008)the key Project of Science and Technology of Shantou[Grant No.(2018)37]and the Natural Science Foundation of Guangdong Province of China(Grant No.2020A1515010094).
文摘Objective:Our aim was to test the hypothesis that fatty acid synthase(FASN)expression contributes to radioresistance of nasopharyngeal carcinoma(NPC)cells and that inhibiting FASN enhances radiosensitivity.Methods:Targeting FASN using epigallocatechin gallate(EGCG)or RNA interference in NPC cell lines that overexpress endogenous FASN was performed to determine their effects on cellular response to radiationin vitro using MTT and colony formation assays,andin vivo using xenograft animal models.Western blot,immunohistochemistry,real-time PCR arrays,and real-time RT-PCR were used to determine the relationship between FASN and frizzled class receptor 10(FZD10)expression.FZD10 knockdown and overexpression were used to determine its role in mediating FASN function in cellular response to radiation.Immunohistochemical staining was used to determine FASN and FZD10 expressions in human NPC tissues,followed by analysis of their association with the overall survival of patients.Results:FASN knockdown or inhibition significantly enhanced radiosensitivity of NPC cells,bothin vitro andin vivo.There was a positive association between FASN and FZD10 expression in NPC cell lines grown as monolayers or xenografts,as well as human tissues.FASN knockdown reduced FZD10 expression,and rescue of FZD10 expression abolished FASN knockdown-induced enhancement of radiosensitivity.FASN and FZD10 were both negatively associated with overall survival of NPC patients.Conclusions:FASN contributes to radioresistance,possiblyvia FZD10 in NPC cells.Both FZD10 and FASN expressions were associated with poor outcomes of NPC patients.EGCG may sensitize radioresistance by inhibiting FASN and may possibly be developed as a radiosensitizer for better treatment of NPCs.
