Recent studies have shown that tea polyphenols can cross the blood-brain barrier, inhibit apoptosis and play a neuroprotective role against cerebral ischemia. Furthermore, tea polyphenols can decrease DNA damage cause...Recent studies have shown that tea polyphenols can cross the blood-brain barrier, inhibit apoptosis and play a neuroprotective role against cerebral ischemia. Furthermore, tea polyphenols can decrease DNA damage caused by free radicals. We hypothesized that tea polyphenols repair DNA damage and inhibit neuronal apoptosis during global cerebral ischemia/reperfusion. To test this hypothesis, we employed a rat model of global cerebral ischemia/reperfusion. We demonstrated that intraperitoneal injection of tea polyphenols immediately after reperfusion significantly reduced apoptosis in the hippocampal CA1 region; this effect started 6 hours following reperfusion. Immunohistochemical staining showed that tea polyphenols could reverse the ischemia/reperfusion-induced reduction in the expression of DNA repair proteins, X-ray repair cross-complementing protein 1 and apudnic/apyrimidinic endonuclease/redox factor-1 starting at 2 hours. Both effects lasted at least 72 hours. These experimental findings suggest that tea polyphenols promote DNA damage repair and protect against apoptosis in the brain.展开更多
Tianfu No. 1 is bred from a plant in the population of Sichuan through system selection,which is characterized with early and uniform germination,hypertrophic shoots,full cover with pekoes and long picking period of s...Tianfu No. 1 is bred from a plant in the population of Sichuan through system selection,which is characterized with early and uniform germination,hypertrophic shoots,full cover with pekoes and long picking period of single shoots. Compared with those of Fuding white tea（ CK）,the fresh leaf yield,tea polyphenols content,free amino acids content,caffeine content and soluble sugar content of Tianfu No. 1 were increased by 8. 89%,6. 98%,10. 00%,2. 96% and31. 58%,respectively. Tianfu No. 1 is a new rare breakthrough tea variety with high development potential,good intrinsic biochemical quality,and strong adaptability for processing multi-typed tea products such as green tea,white tea,black tea and dark tea,etc. It has strong stress resistance and can still grow better in low-humidity areas. In addition,it is not easy to flower and fruit.展开更多
Chlorophyll contributes to tea coloration, which is an important factor in tea quality. Chlorophyll metabolism is induced by light, but the transcriptional regulation responsible for light-induced chlorophyll metaboli...Chlorophyll contributes to tea coloration, which is an important factor in tea quality. Chlorophyll metabolism is induced by light, but the transcriptional regulation responsible for light-induced chlorophyll metabolism is largely unknown in tea leaves. Here, we characterized a chlorophyllase1 gene CsCLH1 from young tea leaves and showed it is essential for chlorophyll metabolism, using transient overexpression and silencing in tea leaves and ectopic overexpression in Arabidopsis. CsCLH1 was significantly induced by high light. The DOF protein CsDOF3, an upstream direct regulator of CsCLH1, was also identified. Acting as a nuclear-localized transcriptional factor, CsDOF3 responded for light and repressed CsCLH1 transcription and increased chlorophyll content by directly binding to the AAAG cis-element in the CsCLH1 promoter. CsDOF3was able to physically interact with the R2R3-MYB transcription factor CsMYB308 and interfere with transcriptional activity of CsCLH1. In addition, CsMYB308 binds to the CsCLH1 promoter to enhance CsCLH1 expression and decrease chlorophyll content. CsMYB308 and CsDOF3 act as an antagonistic complex to regulate CsCLH1 transcription and chlorophyll in young leaves. Collectively, the study adds to the understanding of the transcriptional regulation of chlorophyll in tea leaves in response to light and provides a basis for improving the appearance of tea.展开更多
Objective: Tea polyphenols present in green tea show cancer chemopreventive effects in many tumor models. Epidemiological studies have also suggested that green tea consumption might be effective in the prevention of ...Objective: Tea polyphenols present in green tea show cancer chemopreventive effects in many tumor models. Epidemiological studies have also suggested that green tea consumption might be effective in the prevention of certain human cancers. In the present study, we investigated the molecular mechanisms of the inhibition of cell proliferation by tea polyphenols in nasopharyngeal carcinoma (NPC) cell line CNE1-LMP1. Methods: CNE1-LMP1 cells were treated with tea polyphenols at various doses (0, 25, 50, 100, 200 μg/ml) for 24 hours, the morphology of cells was observed by light microscopy, and cell survival rate was determined by MTT assay. At the same time, cell cycle of CNE1-LMP1 was analyzed by flow cytometry. Cyclin D1 transcription was analyzed by cyclin D1 promoterluciferase reporter system and expression of cyclin D1 protein by Western blot analysis. Transactivities of NF-κB and AP-1 was analyzed by Dual-fluorescence reporter gene system. Results: After treatment of CNE1-LMP1 cells with tea polyphenols, the number of proliferating cells was obviously decreased as determined by light microscopy and MTT assay (from 100% to 89.4%, 83.3%, 74.8% and 38.1%). With the increase of tea polyphenols concentrations, the number of cells in S-phase was obviously decreased, and the number of cells in G1-phase from 22.20% to 13.16%, and the number of cells in G0/G1 phase was elevated from 68.5% to 74.08%. It suggests that tea polyphenols could arrest the cell cycle at both of the two checkpoints. Furthermore, transcription and were obviously declined 7–8 folds (100–200 μg/ml tea polyphenols or EGCG group) and expression of cyclin D1 protein also decreased in a dose-dependent manner. Transactivities of NF-κB and AP-1 were obviously down-regulated in CNE1-LMP1 cells. Conclusion: Green tea polyphenols could inhibit cell proliferation, by suppressing the activity of NF-κB and AP-1, and by down-regulation of the transcription of cyclin D1.展开更多
Objective:It is well known that stress plays a critical role in immune response and susceptibility to diseases.Among many stressors,restraint stress has been shown to suppress immune function and increase susceptibili...Objective:It is well known that stress plays a critical role in immune response and susceptibility to diseases.Among many stressors,restraint stress has been shown to suppress immune function and increase susceptibility to infections.In this study,we employed a restraint-mouse model to investigate the effect and preliminary mechanism of ShiQi herbal tea(SQHT),a traditional Chinese medicine,on H1N1 virus infection.Methods:Mice were exposed to restraint stress and infected with H1N1 influenza virus by intranasal inoculation.SQHT(936 and 1872 mg/kg/d)was orally administrated to mice for 7 days from the first day of restraint stress.The survival rate of mice in each group was monitored daily for 21 days.Histopathological changes,inflammatory cells infiltration,and virus titer in lungs were examined.For the study of mechanisms,we investigated whether SQHT could promote interferon-β(IFN-β)generation and interferon stimulated genes(ISG)expression.Results:Our results suggested that SQHT(936 mg/kg/d)significantly reduced H1N1-induced mortality,the level of complement C5a and lung tissue inflammation,and viral replication in restraint-stressed mice.Further results revealed that in restraint-stressed mice model,SQHT(936 mg/kg/d)administration markedly improved IFN-βgeneration,and increased MX1 and IFITM3 gene expression.Conclusion:Our study demonstrates that SQHT reduces restraint stress-induced susceptibility to H1N1 infection via improving IFN-βantiviral pathway,which provides a certain basis for the clinical use of SQHT to treat H1N1 infection.展开更多
基金supported by the National Natural Science Foundation of China, No. 30571790
文摘Recent studies have shown that tea polyphenols can cross the blood-brain barrier, inhibit apoptosis and play a neuroprotective role against cerebral ischemia. Furthermore, tea polyphenols can decrease DNA damage caused by free radicals. We hypothesized that tea polyphenols repair DNA damage and inhibit neuronal apoptosis during global cerebral ischemia/reperfusion. To test this hypothesis, we employed a rat model of global cerebral ischemia/reperfusion. We demonstrated that intraperitoneal injection of tea polyphenols immediately after reperfusion significantly reduced apoptosis in the hippocampal CA1 region; this effect started 6 hours following reperfusion. Immunohistochemical staining showed that tea polyphenols could reverse the ischemia/reperfusion-induced reduction in the expression of DNA repair proteins, X-ray repair cross-complementing protein 1 and apudnic/apyrimidinic endonuclease/redox factor-1 starting at 2 hours. Both effects lasted at least 72 hours. These experimental findings suggest that tea polyphenols promote DNA damage repair and protect against apoptosis in the brain.
基金Supported by Sichuan Financial Public-Welfare Deepened Engineering Research Project(2016GYSH-019)Earmarked Fund for China Agriculture Research System(CARS-19)
文摘Tianfu No. 1 is bred from a plant in the population of Sichuan through system selection,which is characterized with early and uniform germination,hypertrophic shoots,full cover with pekoes and long picking period of single shoots. Compared with those of Fuding white tea（ CK）,the fresh leaf yield,tea polyphenols content,free amino acids content,caffeine content and soluble sugar content of Tianfu No. 1 were increased by 8. 89%,6. 98%,10. 00%,2. 96% and31. 58%,respectively. Tianfu No. 1 is a new rare breakthrough tea variety with high development potential,good intrinsic biochemical quality,and strong adaptability for processing multi-typed tea products such as green tea,white tea,black tea and dark tea,etc. It has strong stress resistance and can still grow better in low-humidity areas. In addition,it is not easy to flower and fruit.
基金supported by National Natural Science Foundation of China (Grant No.31700609)Natural Science Foundation of Shandong Province (Grant No.ZR2017BC086)State Key Laboratory of Tea Plant Biology and Utilization Open Foundation(Grant No.SKLTOF20180104)。
文摘Chlorophyll contributes to tea coloration, which is an important factor in tea quality. Chlorophyll metabolism is induced by light, but the transcriptional regulation responsible for light-induced chlorophyll metabolism is largely unknown in tea leaves. Here, we characterized a chlorophyllase1 gene CsCLH1 from young tea leaves and showed it is essential for chlorophyll metabolism, using transient overexpression and silencing in tea leaves and ectopic overexpression in Arabidopsis. CsCLH1 was significantly induced by high light. The DOF protein CsDOF3, an upstream direct regulator of CsCLH1, was also identified. Acting as a nuclear-localized transcriptional factor, CsDOF3 responded for light and repressed CsCLH1 transcription and increased chlorophyll content by directly binding to the AAAG cis-element in the CsCLH1 promoter. CsDOF3was able to physically interact with the R2R3-MYB transcription factor CsMYB308 and interfere with transcriptional activity of CsCLH1. In addition, CsMYB308 binds to the CsCLH1 promoter to enhance CsCLH1 expression and decrease chlorophyll content. CsMYB308 and CsDOF3 act as an antagonistic complex to regulate CsCLH1 transcription and chlorophyll in young leaves. Collectively, the study adds to the understanding of the transcriptional regulation of chlorophyll in tea leaves in response to light and provides a basis for improving the appearance of tea.
基金supported by National Natural Science Foundation of China(No.30000087)"973"National Key Basic Research Program of China(No.G1998051201)the National Scientific Research Foundation for Excellent Young Scientist of China(No.39525022)
文摘Objective: Tea polyphenols present in green tea show cancer chemopreventive effects in many tumor models. Epidemiological studies have also suggested that green tea consumption might be effective in the prevention of certain human cancers. In the present study, we investigated the molecular mechanisms of the inhibition of cell proliferation by tea polyphenols in nasopharyngeal carcinoma (NPC) cell line CNE1-LMP1. Methods: CNE1-LMP1 cells were treated with tea polyphenols at various doses (0, 25, 50, 100, 200 μg/ml) for 24 hours, the morphology of cells was observed by light microscopy, and cell survival rate was determined by MTT assay. At the same time, cell cycle of CNE1-LMP1 was analyzed by flow cytometry. Cyclin D1 transcription was analyzed by cyclin D1 promoterluciferase reporter system and expression of cyclin D1 protein by Western blot analysis. Transactivities of NF-κB and AP-1 was analyzed by Dual-fluorescence reporter gene system. Results: After treatment of CNE1-LMP1 cells with tea polyphenols, the number of proliferating cells was obviously decreased as determined by light microscopy and MTT assay (from 100% to 89.4%, 83.3%, 74.8% and 38.1%). With the increase of tea polyphenols concentrations, the number of cells in S-phase was obviously decreased, and the number of cells in G1-phase from 22.20% to 13.16%, and the number of cells in G0/G1 phase was elevated from 68.5% to 74.08%. It suggests that tea polyphenols could arrest the cell cycle at both of the two checkpoints. Furthermore, transcription and were obviously declined 7–8 folds (100–200 μg/ml tea polyphenols or EGCG group) and expression of cyclin D1 protein also decreased in a dose-dependent manner. Transactivities of NF-κB and AP-1 were obviously down-regulated in CNE1-LMP1 cells. Conclusion: Green tea polyphenols could inhibit cell proliferation, by suppressing the activity of NF-κB and AP-1, and by down-regulation of the transcription of cyclin D1.
基金This work was financially supported,in part,by Science and Technology Project of Zhongshan(2013A3FC0253)Scientific Research Team Training Project in University of Electronic Science and Technology of China,Zhongshan Institute(No.412YT02)Natural Science Foundation of Guangdong Province-the Ph.D.Startup and Vertical Collaboration Project(2018030310186).
文摘Objective:It is well known that stress plays a critical role in immune response and susceptibility to diseases.Among many stressors,restraint stress has been shown to suppress immune function and increase susceptibility to infections.In this study,we employed a restraint-mouse model to investigate the effect and preliminary mechanism of ShiQi herbal tea(SQHT),a traditional Chinese medicine,on H1N1 virus infection.Methods:Mice were exposed to restraint stress and infected with H1N1 influenza virus by intranasal inoculation.SQHT(936 and 1872 mg/kg/d)was orally administrated to mice for 7 days from the first day of restraint stress.The survival rate of mice in each group was monitored daily for 21 days.Histopathological changes,inflammatory cells infiltration,and virus titer in lungs were examined.For the study of mechanisms,we investigated whether SQHT could promote interferon-β(IFN-β)generation and interferon stimulated genes(ISG)expression.Results:Our results suggested that SQHT(936 mg/kg/d)significantly reduced H1N1-induced mortality,the level of complement C5a and lung tissue inflammation,and viral replication in restraint-stressed mice.Further results revealed that in restraint-stressed mice model,SQHT(936 mg/kg/d)administration markedly improved IFN-βgeneration,and increased MX1 and IFITM3 gene expression.Conclusion:Our study demonstrates that SQHT reduces restraint stress-induced susceptibility to H1N1 infection via improving IFN-βantiviral pathway,which provides a certain basis for the clinical use of SQHT to treat H1N1 infection.
