Insulin resistance is a key pathological process in the development of type 2 diabetes,which can also lead to depression,anxiety and other symptoms.With the accelerated pace of life,food with high-energy and additives...Insulin resistance is a key pathological process in the development of type 2 diabetes,which can also lead to depression,anxiety and other symptoms.With the accelerated pace of life,food with high-energy and additives is becoming more and more common in people's diet.Propionate is a naturally existing short-chain fatty acid salt widely used as a food preservative,but studies have found that low concentrations of propionate can induce insulin resistance.Theaflavins(TFs)are characteristic components of black tea,which have hypoglycemic and lipid-lowering effects.In the present study,propionate combined with high-fat diet was used to induce insulin resistance in mice and treated them with TFs.The results showed that propionate could aggravate insulin resistance and anxiety induced by high-fat diet in mice.TFs alleviated insulin resistance and anxiety induced by propionate combined with high-fat diet by improving the disorder of metabolic gene expression and inflammation in the adipose and liver tissue,as well as neuroinflammation in the brain.Our study suggests that the food additive propionate combined with a high-fat diet may be harmful to organismal health.As a natural drug,TFs have the potential to alleviate insulin resistance induced by propionate combined with high-fat diet.展开更多
This study was carried out to characterize total residual catechins and their fractions, polyphenolic contents and antioxidant activities of black teas enriched with high levels of theaflavin-3,3’-digallate. The made...This study was carried out to characterize total residual catechins and their fractions, polyphenolic contents and antioxidant activities of black teas enriched with high levels of theaflavin-3,3’-digallate. The made teas were processed from eleven selected cultivars. A comparative study was carried out between the processed teas and those from commercially grown Kenyan cultivars in relation to the above chemical parameters. A correlation matrix analysis was also conducted to find out whether a relationship existed between the antioxidant activities and the said chemical parameters. The total residual catechins were found to range between 3.10% and 8.08%. The total polyphenol levels varied between 19.00% and 28.90%, while the antioxidant activities of the teas ranged from 82.70% to 91.70%. There was a significant p < 0.001 correlation between the antioxidant activity and total polyphenols (r = 0.8948). There was also a high correlation p < 0.001 between the antioxidant activity and total catechins (r = 0.8878). Out of the four catechin fractions, the antioxidant activity correlated most with EGCG (r = 0.8774). The total polyphenolic contents and antioxidant activities for most of the cultivars were comparable to those of the green tea reference standard. From the figures obtained, it can be concluded that the most of the newly developed black teas of the selected cultivars have higher quality and enhanced antioxidant activities and that they can be recommended for commercial production.展开更多
Theaflavins(TFs),as the major polyphenolic components of fermented tea,possess beneficial effects on human health.In this study,the effervescent tablets based on theaflavins were developed.The optimal formulation of T...Theaflavins(TFs),as the major polyphenolic components of fermented tea,possess beneficial effects on human health.In this study,the effervescent tablets based on theaflavins were developed.The optimal formulation of TF effervescent tablets was obtained by response surface methodology with the Box-Behnken design.Then,the physiochemical properties were evaluated,including hardness,friability,effervescent time and pH of the solution.At last,the antioxidant ability of TF effervescent tablets was studied through DPPH and ABTS radical scavenging assay.According to the results,the optimal formulation of the tablets contained TF powder 9.09%,disintegrating agent 43.80%(the weight ratio of citric acid and sodium bicarbonate was 1:1),aspartame 1.86%,PEG-6003%,and mannitol in balance.With the wet granulation method,the TF effervescent tablets displayed suitable hardness,fast disintegration time,good color,pleasant taste and high antioxidant activity.This study demonstrated that the TF effervescent tablets could be a valuable product for the supplement market and contribute to promoting practical application of TFs.展开更多
This study involved the selection of 11 cultivars out of 201 screened cultivars of fresh green and purple coloured tea leaves for use in the manufacture of black teas with optimized antioxidant activities. Individual ...This study involved the selection of 11 cultivars out of 201 screened cultivars of fresh green and purple coloured tea leaves for use in the manufacture of black teas with optimized antioxidant activities. Individual cultivars containing a combination of high leaf concentrations of the catechin fractions;epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) were used in the processing of theaflavin-3,3’ digallate (TF3) rich black tea. The black tea enrichment with TF3 was carried out through optimization of the processing conditions of each cultivar by varying the aeration times between 0 min and 80 min at an interval of 20 min. The differently processed teas were then assayed for the TF3 contents. The data analysis was carried out using the GENSTAT at p ≤ 0.05. The optimal processing time for Ejulu, TRFK 832/8, TRFK 831/11, TRFK 824/1, SC 31/37, SC 12/28, K-Purple and TRFK 6/8 was found to be 60 min while that of TRFK 301/6, TRFK 301/3 and TRFK 655/1 was 40 min. The optimal TF3 levels were found to range from 0.19% to 0.60%.展开更多
Theaflavins(TFs) are the dimers of a couple of epimerized catechins,which are specially formed during black tea fermentation.To explore the differences among four main TF derivatives(theaflavin(TF 1),theaflavin3-galla...Theaflavins(TFs) are the dimers of a couple of epimerized catechins,which are specially formed during black tea fermentation.To explore the differences among four main TF derivatives(theaflavin(TF 1),theaflavin3-gallate(TF 2 A),theaflavin-3'-gallate(TF 2 B),and theaflavin-3,3'-digallate(TF 3)) in scavenging reactive oxygen species(ROS) in vitro,their properties of inhibiting superoxide,singlet oxygen,hydrogen peroxide,and the hydroxyl radical,and their effects on hydroxyl radical-induced DNA oxidative damage were systematically analyzed in the present study.The results show that,compared with()-epigallocatechin gallate(EGCG),TF derivatives were good antioxidants for scavenging ROS and preventing the hydroxyl radical-induced DNA damage in vitro.TF 3 was the most positive in scavenging hydrogen peroxide and hydroxyl radical,and TF 1 suppressed superoxide.Positive antioxidant capacities of TF 2 B on singlet oxygen,hydrogen peroxide,hydroxyl radical,and the hydroxyl radical-induced DNA damage in vitro were found.The differences between the antioxidant capacities of four main TF derivatives in relation to their chemical structures were also discussed.We suggest that these activity differences among TF derivatives would be beneficial to scavenge different ROS with therapeutic potential.展开更多
Increasing evidence has shown that gut microbiota plays important roles in metabolizing large molecular polyphenols to bioavailable and bioactive microbial metabolites.Theaflavin(TF)is one of the major color compounds...Increasing evidence has shown that gut microbiota plays important roles in metabolizing large molecular polyphenols to bioavailable and bioactive microbial metabolites.Theaflavin(TF)is one of the major color compounds in black tea and has demonstrated anti-inflammation,antioxidant,and anticancer effects properties.However,little is known about the metabolism of TF by gut microbiota in vivo.In this study,following the administration of TF to mice,the C-ring cleavage metabolites,dihydro-and tetrahydro-theaflavin(DH-TF and TH-TF)were detected in mouse feces by LC-MS and validated by authentic standards from in situ chemical reaction.The observation of the C-ring cleavage metabolites in TF-treated conventionalized mice but not in germ-free(GF)mice confirmed the role of gut microbiota in cleaving the C-rings of TF.The detection of DH-TF from the anaerobic incubation of TF with catechin-converting gut bacteria,Eggerthella lenta(Eggerth),suggested that the microbes with the capacity to cleave the C-ring of catechins were able to metabolize TF following the same mechanism.Additionally,three small phenolic metabolites were detected in mouse feces,and one of them was primarily detected in SPF mice not GF mice,which revealed that TF,subsequent to the cleaved C-ring,can be further metabolized into smaller phenolic metabolites by gut microbiota.Dose-dependent production of these metabolites were observed from the administration of 100 mg/kg to 400 mg/kg body weight of TF.In conclusion,gut microbiota can metabolize TF to the open-ring metabolites and the phenolic metabolites through the C-ring cleavage in mice.展开更多
A graphical index is a numeric value corresponding to a graph which is structurally invariant and in molecular graph theory these invariants are known as topological indices. In the field of Chemical and Medical Scien...A graphical index is a numeric value corresponding to a graph which is structurally invariant and in molecular graph theory these invariants are known as topological indices. In the field of Chemical and Medical Sciences, the topological indices are used to study the chemical, biological, medical and pharmaceutical features of drugs. With reference to the previous deadly diseases, the COVID-19 pandemic has considered to be the biggest life threatening issue that modern medicines have ever tackled. COVID-19 is immedicable and even the existing treatments are only helping the certain group of sufferers. Scientists have tested available antiviral agents and got a favorable impact on recovering from pandemic. Some of these antiviral agents are remdesivir, chloroquine, hydroxychloroquine, theaflavin and dexamethasone. Keeping in view of the importance of topological indices in the study of pharmaceutical and chemical drugs, in this paper, we calculate the <em>M<sub>dn</sub></em>-Polynomial, some downhill Zagreb topological indices and some downhill Zagreb polynomials of some of the anti viral agents remdesivir, chloroquine, hydroxychloroquine, theaflavin and dexamethasone. The results thus obtained may be useful for the finding new medicine and vaccine for the treatment of COVID-19.展开更多
Theqflavin(TF) was extracted and purified from black broken tea. The purified TF possessed an absorption peak at the 363nm wavelength, and the solutions of TF remained stable under the conditions of pH3-6, below 80℃ ...Theqflavin(TF) was extracted and purified from black broken tea. The purified TF possessed an absorption peak at the 363nm wavelength, and the solutions of TF remained stable under the conditions of pH3-6, below 80℃ within 60 minutes, as well as in 1%-4% Vc and 0.05-0.5mmol /L Na_(2)SO_(3) solutions. Fading occurred in 0.05mol/L Hf)^ solution.展开更多
基金jointly supported by Special Fund for Basic Research on Scientific Instruments of the Chinese National Natural Science Foundation(62027812)National Innovation and Entrepreneurship Project for College Students(202210055092)。
文摘Insulin resistance is a key pathological process in the development of type 2 diabetes,which can also lead to depression,anxiety and other symptoms.With the accelerated pace of life,food with high-energy and additives is becoming more and more common in people's diet.Propionate is a naturally existing short-chain fatty acid salt widely used as a food preservative,but studies have found that low concentrations of propionate can induce insulin resistance.Theaflavins(TFs)are characteristic components of black tea,which have hypoglycemic and lipid-lowering effects.In the present study,propionate combined with high-fat diet was used to induce insulin resistance in mice and treated them with TFs.The results showed that propionate could aggravate insulin resistance and anxiety induced by high-fat diet in mice.TFs alleviated insulin resistance and anxiety induced by propionate combined with high-fat diet by improving the disorder of metabolic gene expression and inflammation in the adipose and liver tissue,as well as neuroinflammation in the brain.Our study suggests that the food additive propionate combined with a high-fat diet may be harmful to organismal health.As a natural drug,TFs have the potential to alleviate insulin resistance induced by propionate combined with high-fat diet.
文摘This study was carried out to characterize total residual catechins and their fractions, polyphenolic contents and antioxidant activities of black teas enriched with high levels of theaflavin-3,3’-digallate. The made teas were processed from eleven selected cultivars. A comparative study was carried out between the processed teas and those from commercially grown Kenyan cultivars in relation to the above chemical parameters. A correlation matrix analysis was also conducted to find out whether a relationship existed between the antioxidant activities and the said chemical parameters. The total residual catechins were found to range between 3.10% and 8.08%. The total polyphenol levels varied between 19.00% and 28.90%, while the antioxidant activities of the teas ranged from 82.70% to 91.70%. There was a significant p < 0.001 correlation between the antioxidant activity and total polyphenols (r = 0.8948). There was also a high correlation p < 0.001 between the antioxidant activity and total catechins (r = 0.8878). Out of the four catechin fractions, the antioxidant activity correlated most with EGCG (r = 0.8774). The total polyphenolic contents and antioxidant activities for most of the cultivars were comparable to those of the green tea reference standard. From the figures obtained, it can be concluded that the most of the newly developed black teas of the selected cultivars have higher quality and enhanced antioxidant activities and that they can be recommended for commercial production.
基金Supported by Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization,Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains Fund(2021CX06)。
文摘Theaflavins(TFs),as the major polyphenolic components of fermented tea,possess beneficial effects on human health.In this study,the effervescent tablets based on theaflavins were developed.The optimal formulation of TF effervescent tablets was obtained by response surface methodology with the Box-Behnken design.Then,the physiochemical properties were evaluated,including hardness,friability,effervescent time and pH of the solution.At last,the antioxidant ability of TF effervescent tablets was studied through DPPH and ABTS radical scavenging assay.According to the results,the optimal formulation of the tablets contained TF powder 9.09%,disintegrating agent 43.80%(the weight ratio of citric acid and sodium bicarbonate was 1:1),aspartame 1.86%,PEG-6003%,and mannitol in balance.With the wet granulation method,the TF effervescent tablets displayed suitable hardness,fast disintegration time,good color,pleasant taste and high antioxidant activity.This study demonstrated that the TF effervescent tablets could be a valuable product for the supplement market and contribute to promoting practical application of TFs.
文摘This study involved the selection of 11 cultivars out of 201 screened cultivars of fresh green and purple coloured tea leaves for use in the manufacture of black teas with optimized antioxidant activities. Individual cultivars containing a combination of high leaf concentrations of the catechin fractions;epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) were used in the processing of theaflavin-3,3’ digallate (TF3) rich black tea. The black tea enrichment with TF3 was carried out through optimization of the processing conditions of each cultivar by varying the aeration times between 0 min and 80 min at an interval of 20 min. The differently processed teas were then assayed for the TF3 contents. The data analysis was carried out using the GENSTAT at p ≤ 0.05. The optimal processing time for Ejulu, TRFK 832/8, TRFK 831/11, TRFK 824/1, SC 31/37, SC 12/28, K-Purple and TRFK 6/8 was found to be 60 min while that of TRFK 301/6, TRFK 301/3 and TRFK 655/1 was 40 min. The optimal TF3 levels were found to range from 0.19% to 0.60%.
基金Project supported by the National Natural Science Foundation of China (No. 30901002)the Fundamental Research Funds for the Central Universitiesthe China Postdoctoral Science Foundation Funded Project (No. 20070421210)
文摘Theaflavins(TFs) are the dimers of a couple of epimerized catechins,which are specially formed during black tea fermentation.To explore the differences among four main TF derivatives(theaflavin(TF 1),theaflavin3-gallate(TF 2 A),theaflavin-3'-gallate(TF 2 B),and theaflavin-3,3'-digallate(TF 3)) in scavenging reactive oxygen species(ROS) in vitro,their properties of inhibiting superoxide,singlet oxygen,hydrogen peroxide,and the hydroxyl radical,and their effects on hydroxyl radical-induced DNA oxidative damage were systematically analyzed in the present study.The results show that,compared with()-epigallocatechin gallate(EGCG),TF derivatives were good antioxidants for scavenging ROS and preventing the hydroxyl radical-induced DNA damage in vitro.TF 3 was the most positive in scavenging hydrogen peroxide and hydroxyl radical,and TF 1 suppressed superoxide.Positive antioxidant capacities of TF 2 B on singlet oxygen,hydrogen peroxide,hydroxyl radical,and the hydroxyl radical-induced DNA damage in vitro were found.The differences between the antioxidant capacities of four main TF derivatives in relation to their chemical structures were also discussed.We suggest that these activity differences among TF derivatives would be beneficial to scavenge different ROS with therapeutic potential.
文摘Increasing evidence has shown that gut microbiota plays important roles in metabolizing large molecular polyphenols to bioavailable and bioactive microbial metabolites.Theaflavin(TF)is one of the major color compounds in black tea and has demonstrated anti-inflammation,antioxidant,and anticancer effects properties.However,little is known about the metabolism of TF by gut microbiota in vivo.In this study,following the administration of TF to mice,the C-ring cleavage metabolites,dihydro-and tetrahydro-theaflavin(DH-TF and TH-TF)were detected in mouse feces by LC-MS and validated by authentic standards from in situ chemical reaction.The observation of the C-ring cleavage metabolites in TF-treated conventionalized mice but not in germ-free(GF)mice confirmed the role of gut microbiota in cleaving the C-rings of TF.The detection of DH-TF from the anaerobic incubation of TF with catechin-converting gut bacteria,Eggerthella lenta(Eggerth),suggested that the microbes with the capacity to cleave the C-ring of catechins were able to metabolize TF following the same mechanism.Additionally,three small phenolic metabolites were detected in mouse feces,and one of them was primarily detected in SPF mice not GF mice,which revealed that TF,subsequent to the cleaved C-ring,can be further metabolized into smaller phenolic metabolites by gut microbiota.Dose-dependent production of these metabolites were observed from the administration of 100 mg/kg to 400 mg/kg body weight of TF.In conclusion,gut microbiota can metabolize TF to the open-ring metabolites and the phenolic metabolites through the C-ring cleavage in mice.
文摘A graphical index is a numeric value corresponding to a graph which is structurally invariant and in molecular graph theory these invariants are known as topological indices. In the field of Chemical and Medical Sciences, the topological indices are used to study the chemical, biological, medical and pharmaceutical features of drugs. With reference to the previous deadly diseases, the COVID-19 pandemic has considered to be the biggest life threatening issue that modern medicines have ever tackled. COVID-19 is immedicable and even the existing treatments are only helping the certain group of sufferers. Scientists have tested available antiviral agents and got a favorable impact on recovering from pandemic. Some of these antiviral agents are remdesivir, chloroquine, hydroxychloroquine, theaflavin and dexamethasone. Keeping in view of the importance of topological indices in the study of pharmaceutical and chemical drugs, in this paper, we calculate the <em>M<sub>dn</sub></em>-Polynomial, some downhill Zagreb topological indices and some downhill Zagreb polynomials of some of the anti viral agents remdesivir, chloroquine, hydroxychloroquine, theaflavin and dexamethasone. The results thus obtained may be useful for the finding new medicine and vaccine for the treatment of COVID-19.
文摘Theqflavin(TF) was extracted and purified from black broken tea. The purified TF possessed an absorption peak at the 363nm wavelength, and the solutions of TF remained stable under the conditions of pH3-6, below 80℃ within 60 minutes, as well as in 1%-4% Vc and 0.05-0.5mmol /L Na_(2)SO_(3) solutions. Fading occurred in 0.05mol/L Hf)^ solution.
