Background:Vine tea from fermented Ampelopsis grossedentata leaves has been used as a herbal tea and folk medicine in the southern region of China for hundreds of years.The aim of this investigation was to analyze the...Background:Vine tea from fermented Ampelopsis grossedentata leaves has been used as a herbal tea and folk medicine in the southern region of China for hundreds of years.The aim of this investigation was to analyze the total flavonoids found in vine tea,including three bioactive flavonoids,and the total phenolic contents in the aqueous methanol extracts of 10 vine tea samples.In addition,this study also aimed to examine the antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract.Methods:The total flavonoids and total phenolic content assay of extracts from vine tea were performed by ultraviolet-visible spectroscopy and epoch microplate spectrophotometer,respectively.Three bioactive flavonoids were quantified simultaneously using high performance liquid chromatography.The antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract was evaluated in vitro using six different methods.Results:Vine tea contained a large number of flavonoids,with dihydromyricetin as its main constituent.The flavonoid-rich extract exhibited a significant scavenging effect on superoxide anion radicals,and on 3-ethylbenzthiazoline-6-sulphonic acid and 1,1-diphenyl-2-picrylhydrazyl radicals.It also possessed definite activity in lipid peroxidation inhibition,ferric reduction,and the moderation of Fe2+ion chelation ability.There was a significant negative correlation between dihydromyricetin content and antioxidant activity in the vine tea samples,including superoxide anion radical scavenging activity(P=−0.754,P<0.05),lipid peroxidation inhibition activity(P=−0.759,P<0.05),ferric-reducing antioxidant power(P=−0.843,P<0.01),respectively.Dihydromyricetin played a dominant role in the antioxidant activities of the flavonoid-rich extract.Conclusion:Vine tea’s flavonoid-rich extract could be used as a new antioxidant source to safeguard against oxidative stress.展开更多
The successful treatment of limb ischemia requires that promote angiogenesis along with microenvironment improvement.Zinc ions have been reported to stimulate angiogenesis,but application was limited to the toxicity c...The successful treatment of limb ischemia requires that promote angiogenesis along with microenvironment improvement.Zinc ions have been reported to stimulate angiogenesis,but application was limited to the toxicity concerns.We hypothesized that zinc based metal-EGCG capsule(EGCG/Zn Ps)can achieve sustained release Zn2+resulting in reduced toxicity and improve angiogenesis as well as the improvement of microenvironment by ROS scavenging of EGCG.The surface morphology,zeta potential,infrared absorbance peaks and zinc ion release profile of the EGCG/Zn Ps were measured.In vitro,EGCG/Zn showed significantly antioxidant,antiinflammatory and induced cell migration effect.In addition,EGCG/Zn Ps enabled the sustained release of zinc ions,which reduced cytotoxicity and enhanced the secretion of vascular endothelial growth factor(VEGF)in vitro and in vivo.In mouse models of limb ischemia,EGCG/Zn Ps promoted angiogenesis and cell proliferation in ischemic tissues.Moreover,EGCG/Zn Ps group exhibited the most significant recovery of limb ischemic score,limb temperature and blood flow than other groups.In conclusion,EGCG/Zn Ps is a safe and promising approach to combine the merit of Zn2+and EGCG,thus enabling the direct application to limb ischemia.展开更多
The ecological and climatic conditions in the main tea areas of western Guizhou were analyzed,and the comparison with Meitan,Duyun and Leishan tea areas in Guizhou Province was conducted. The results showed that sprin...The ecological and climatic conditions in the main tea areas of western Guizhou were analyzed,and the comparison with Meitan,Duyun and Leishan tea areas in Guizhou Province was conducted. The results showed that spring,summer and autumn tea can be picked in western Guizhou Province;spring tea can be picked for about 100 d,and summer and autumn tea can be picked for about 50 d. The average content of amino acids in tea from western Guizhou was 0.9%-2.9% higher than the national average,and the average content of polyphenols was 10.9% lower than the national average maximum,while the average content of caffeine was 1.4% lower than the national average maximum. In the first ten days of February,the temperature in the western tea area began to rise,which was earlier than Meitan,Duyun,Leishan tea areas and had a larger warming range,which was conducive to the germination of tea trees. The average temperature of ten days in the western tea area from middle May to early July was lower than that of Meitan,Duyun and Leishan tea areas,and the temperature rise was not violent,which was conducive to the growth of summer shoots and vigorous growth of tea buds. The ten-day average temperature of the western tea area from the first ten days of August to the last ten days of September was lower than Meitan,Duyun and Leishan tea areas,and its precipitation was more than Meitan,Duyun and Leishan tea areas,and the number of rainy and foggy days was more. The climate conditions are favorable for the formation of tea quality.展开更多
Black tea and green tea are the most important tea in the world.In this paper we analyze the relationship of the world green price and black tea price.The results show that:in the world tea markets,the world black tea...Black tea and green tea are the most important tea in the world.In this paper we analyze the relationship of the world green price and black tea price.The results show that:in the world tea markets,the world black tea price and the world green tea price have no co-integration,independent of the curve segmentation.In the major green tea countries,there are co-integration relationships between China and Japan,China and Brazil,Japan and Brazil,while Vietnam has a first-order stationary sequence.In the major black tea countries,Sri Lanka and India have no co-integration,Sri Lanka and Indonesia no co-integration,India and Indonesia no co-integration,Sri Lanka and Kenya have co-integration,India and Kenya have co-integration,Kenya and Indonesia have co-integration.展开更多
In this paper,single-factor experiments and orthogonal experiment were conducted to optimize the water bath extraction of polyphenols from Qing Brick Tea,and the optimal extraction conditions obtained were as follows:...In this paper,single-factor experiments and orthogonal experiment were conducted to optimize the water bath extraction of polyphenols from Qing Brick Tea,and the optimal extraction conditions obtained were as follows:solvent of 50%ethanol,solid/liquid ratio of 1∶30,temperature of 80℃,and time of 6 min.Under the optimal water bath extraction conditions,polyphenols in fresh tea leaves,fresh tea petioles,fresh tea blades,finished brick tea,finished tea petioles,finished tea blades,tea dregs after brewing and tea dregs after boiling were extracted,respectively.It was found that the quality fraction of polyphenols extracted from fresh tea leaves was the highest,with the best extraction effect.The extraction effect of leaf blades was better than that of leaf petioles,and the extraction effect of tea dregs after brewing was better than that of tea dregs after boiling.展开更多
基金This work was supported by Traditional Chinese Medicine Science and Technology Development Project of Shandong Province(No.2019-0649)Fundamental Research Funds for the Central Universities(No.2018-BUCMXJKY001).
文摘Background:Vine tea from fermented Ampelopsis grossedentata leaves has been used as a herbal tea and folk medicine in the southern region of China for hundreds of years.The aim of this investigation was to analyze the total flavonoids found in vine tea,including three bioactive flavonoids,and the total phenolic contents in the aqueous methanol extracts of 10 vine tea samples.In addition,this study also aimed to examine the antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract.Methods:The total flavonoids and total phenolic content assay of extracts from vine tea were performed by ultraviolet-visible spectroscopy and epoch microplate spectrophotometer,respectively.Three bioactive flavonoids were quantified simultaneously using high performance liquid chromatography.The antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract was evaluated in vitro using six different methods.Results:Vine tea contained a large number of flavonoids,with dihydromyricetin as its main constituent.The flavonoid-rich extract exhibited a significant scavenging effect on superoxide anion radicals,and on 3-ethylbenzthiazoline-6-sulphonic acid and 1,1-diphenyl-2-picrylhydrazyl radicals.It also possessed definite activity in lipid peroxidation inhibition,ferric reduction,and the moderation of Fe2+ion chelation ability.There was a significant negative correlation between dihydromyricetin content and antioxidant activity in the vine tea samples,including superoxide anion radical scavenging activity(P=−0.754,P<0.05),lipid peroxidation inhibition activity(P=−0.759,P<0.05),ferric-reducing antioxidant power(P=−0.843,P<0.01),respectively.Dihydromyricetin played a dominant role in the antioxidant activities of the flavonoid-rich extract.Conclusion:Vine tea’s flavonoid-rich extract could be used as a new antioxidant source to safeguard against oxidative stress.
基金the National Natural Science Foundation of China(Nos.81870351,31771097,81972899)National Key Research and Development Project of China(No.2018YFC2000301)+4 种基金CAMS Innovation Fund for Medical Sciences(CIFMS.2018-I2M-1-002,2017-I2M-1-016)PUMC Discipline Construction Project(No.201920102101)Natural Science Foundation of Beijing Municipality(No.7192186)Fundamental Research Funds for the Central Universities(Nos.3332018185,3332018174)Beijing Hospital Project(No.BJ2018038).
文摘The successful treatment of limb ischemia requires that promote angiogenesis along with microenvironment improvement.Zinc ions have been reported to stimulate angiogenesis,but application was limited to the toxicity concerns.We hypothesized that zinc based metal-EGCG capsule(EGCG/Zn Ps)can achieve sustained release Zn2+resulting in reduced toxicity and improve angiogenesis as well as the improvement of microenvironment by ROS scavenging of EGCG.The surface morphology,zeta potential,infrared absorbance peaks and zinc ion release profile of the EGCG/Zn Ps were measured.In vitro,EGCG/Zn showed significantly antioxidant,antiinflammatory and induced cell migration effect.In addition,EGCG/Zn Ps enabled the sustained release of zinc ions,which reduced cytotoxicity and enhanced the secretion of vascular endothelial growth factor(VEGF)in vitro and in vivo.In mouse models of limb ischemia,EGCG/Zn Ps promoted angiogenesis and cell proliferation in ischemic tissues.Moreover,EGCG/Zn Ps group exhibited the most significant recovery of limb ischemic score,limb temperature and blood flow than other groups.In conclusion,EGCG/Zn Ps is a safe and promising approach to combine the merit of Zn2+and EGCG,thus enabling the direct application to limb ischemia.
基金Supported by the Special Project for Building Science and Technology Cooperation and Innovation Capacity in Guizhou Province(52020-2015-01-02)。
文摘The ecological and climatic conditions in the main tea areas of western Guizhou were analyzed,and the comparison with Meitan,Duyun and Leishan tea areas in Guizhou Province was conducted. The results showed that spring,summer and autumn tea can be picked in western Guizhou Province;spring tea can be picked for about 100 d,and summer and autumn tea can be picked for about 50 d. The average content of amino acids in tea from western Guizhou was 0.9%-2.9% higher than the national average,and the average content of polyphenols was 10.9% lower than the national average maximum,while the average content of caffeine was 1.4% lower than the national average maximum. In the first ten days of February,the temperature in the western tea area began to rise,which was earlier than Meitan,Duyun,Leishan tea areas and had a larger warming range,which was conducive to the germination of tea trees. The average temperature of ten days in the western tea area from middle May to early July was lower than that of Meitan,Duyun and Leishan tea areas,and the temperature rise was not violent,which was conducive to the growth of summer shoots and vigorous growth of tea buds. The ten-day average temperature of the western tea area from the first ten days of August to the last ten days of September was lower than Meitan,Duyun and Leishan tea areas,and its precipitation was more than Meitan,Duyun and Leishan tea areas,and the number of rainy and foggy days was more. The climate conditions are favorable for the formation of tea quality.
文摘Black tea and green tea are the most important tea in the world.In this paper we analyze the relationship of the world green price and black tea price.The results show that:in the world tea markets,the world black tea price and the world green tea price have no co-integration,independent of the curve segmentation.In the major green tea countries,there are co-integration relationships between China and Japan,China and Brazil,Japan and Brazil,while Vietnam has a first-order stationary sequence.In the major black tea countries,Sri Lanka and India have no co-integration,Sri Lanka and Indonesia no co-integration,India and Indonesia no co-integration,Sri Lanka and Kenya have co-integration,India and Kenya have co-integration,Kenya and Indonesia have co-integration.
基金Key Project of Philosophy and Social Science Research in Colleges and Universities of Hubei Province(18ZD030)Cultivation Project of Hubei University of Science and Technology(2020-21X12)Open Fund of Enan Cultural Research Center,Hubei Provincial Key Research Base of Humanities and Social Sciences(2018-19XZE04)。
文摘In this paper,single-factor experiments and orthogonal experiment were conducted to optimize the water bath extraction of polyphenols from Qing Brick Tea,and the optimal extraction conditions obtained were as follows:solvent of 50%ethanol,solid/liquid ratio of 1∶30,temperature of 80℃,and time of 6 min.Under the optimal water bath extraction conditions,polyphenols in fresh tea leaves,fresh tea petioles,fresh tea blades,finished brick tea,finished tea petioles,finished tea blades,tea dregs after brewing and tea dregs after boiling were extracted,respectively.It was found that the quality fraction of polyphenols extracted from fresh tea leaves was the highest,with the best extraction effect.The extraction effect of leaf blades was better than that of leaf petioles,and the extraction effect of tea dregs after brewing was better than that of tea dregs after boiling.