Epicatechin(EC)was used in this study to antagonize the cognitive dysfunction caused by lead(Pb)exposure in mice.Eight-week-old male Kunming mice were treated with PbCl_(2)(20 mg/kg)and/or EC(50 mg/kg)by gavage admini...Epicatechin(EC)was used in this study to antagonize the cognitive dysfunction caused by lead(Pb)exposure in mice.Eight-week-old male Kunming mice were treated with PbCl_(2)(20 mg/kg)and/or EC(50 mg/kg)by gavage administration for 4 weeks.Morris water maze test showed that EC could improve memory dysfunction induced by Pb.EC antagonized Ca^(2+)overload,activated Nrf2 signaling pathway and reduced the accumulation of Pb in the brain and serum,which suggested that EC might alter Pb distribution in mice.In vitro,spectroscopic analysis,potentiometric titration and docking studies were applied to inquiry into the interaction between bovine serum albumin(BSA)and Pb^(2+)in presence or absence of EC.EC was proved to chelate Pb^(2+)and reduced the interaction between BSA and Pb^(2+).In summary,EC might protect Pb-induced cognitive impairment by activating Nrf2 signaling pathway,and suppressing Pb accumulation via interference on the binding of Pb to albumin.展开更多
Catechin and epicatechin are two isomeric flavonoids. Despite the vital properties highlighted by numerous scientific studies, very little data is available on the intrinsic reactivity of these compounds. To provide m...Catechin and epicatechin are two isomeric flavonoids. Despite the vital properties highlighted by numerous scientific studies, very little data is available on the intrinsic reactivity of these compounds. To provide more details on the stability and reactivity of catechin and epicatechin, this study is performed by means of theoretical calculation methods. For this purpose, geometry optimizations and frequency calculations at the B3LYP/6-31 + G (d, p) level of theory has been carried out and Natural Bond Orbital (NBO) analysis and VEDA (Vibrational Energy Distribution Analysis). The geometric and energy parameters and NBO analysis show that catechin appears more stable than epicatechin. The hydroxyl group position on the ring C of the catechol structure represents a factor that influences this relative stability. The global and local reactivity parameters reveal that epicatechin becomes more reactive than catechin. They indicate that their hydroxyl groups correspond to their most receptive sites. Fukui indices, VEDA and acidity study establish that O28–H29 remains the most reactive.展开更多
Epicatechin gallate(ECG)is one of the polyphenolic compounds and has attracted much attention due to its various bioactivities.In this study,the neuroprotective eff ect of ECG against H_(2)O_(2)-induced oxidative inju...Epicatechin gallate(ECG)is one of the polyphenolic compounds and has attracted much attention due to its various bioactivities.In this study,the neuroprotective eff ect of ECG against H_(2)O_(2)-induced oxidative injury in PC12 cells as well as the possible mechanisms were investigated.Cell viability was determined by MTT assay.The differentially expressed genes(DEGs),GO enrichment,and KEGG enrichment were analyzed to explore the mechanism of ECG against H_(2)O_(2)-induced oxidative injury by using the RNA-seq method.Finally,the change in the cell cycle was analyzed by fl ow cytometry.H_(2)O_(2)(400-1200μmol/L)inhibited the cell viability in a concentration-dependent manner.ECG(6-150μmol/L)eff ectively attenuated the H_(2)O_(2)-induced decrease in cell viability.RNA-seq analysis showed that ECG regulated 1058 coexpressed DEGs.GO enrichment analysis showed that the cellular component was the dominant group after ECG treatment.KEGG analysis showed that the cell cycle,fanconi anemia pathway,and homologous recombination were the important pathways for ECG in improving H_(2)O_(2)-induced oxidative injury and 28 coexpressed DEGs in the cell cycle pathway were summarized.Finally,cell cycle analysis also proved that ECG improved H_(2)O_(2)-induced cell cycle arrest in the G2/M phase.Our present study demonstrated that ECG attenuated H_(2)O_(2)-induced neurologic oxidative damage by multiple modulatory mechanisms at the molecular transcription level.These fi ndings provide new insights for further study of the molecular mechanism of the neuroprotection of ECG.展开更多
Hypertension is a major problem worldwide. There is much evidence to suggest that reactive oxygen species (ROS) radical may play a role in the development of organ damage associated with cardiovascular disease and hyp...Hypertension is a major problem worldwide. There is much evidence to suggest that reactive oxygen species (ROS) radical may play a role in the development of organ damage associated with cardiovascular disease and hypertension. (-)Epicatechin, a member of tea catechins belonging to flavonoid group, is known to be a potent anti-oxidant. The study has been undertaken to evaluate the effect of (-)epicatechin on markers of oxidative stress: reduced glutathione (GSH) and membrane sulfhydryl (-SH) groups in erythrocytes from hypertensive patients. The effect of (-)epicatechin was also compared with a known anti-oxidant L-ascorbic acid. The erythrocyte intracellular GSH content and membrane -SH group content were significantly (P<0.01) decreased in hypertensive subjects. In vitro incubation with (-)epicatechin caused an increase in GSH and -SH content, the effect was more pronounced in hypertensive erythrocytes. Similar results were obtained with L-ascorbic acid. The observed decrease in the level of GSH and -SH groups in hypertension is an indicator of oxidative stress condition. Observation of an increase in red cell GSH content and the protection of membrane -SH group oxidation by (-)epicatechin in hypertensive subjects is a convincing reason to suggest that high dietary intake of foods rich in catechins may help to reduce oxidative stress and concomitant free radical damage in hypertensive patients.展开更多
The interaction between BSA and epicatechin was studied using fluorescence quenching titrations combined with trilinear decomposition method and excitation-emission matrix(EEM)fluorescence.The resolved spectra were hi...The interaction between BSA and epicatechin was studied using fluorescence quenching titrations combined with trilinear decomposition method and excitation-emission matrix(EEM)fluorescence.The resolved spectra were highly similar with the actual ones which indicated that the resolved results were reliable.The relevant parameters of the binding process were obtained by quantifying each substance in the complicated mixtures in situ.The quenching was static quenching,epicatechin had a weak interaction with BSA and the binding site was one.The total concentration and the free concentration of quenchers had different effect on the system.The results demonstrated that the method exploited in this article is a useful tool to investigate complicated interactions,avoiding complicated pretreatment and simplify experimental procedure.展开更多
目的:建立HPLC一测多评法(quantitative analysis of multi-components by single marker,QAMS)同时测定蒙药孟根·沃斯-18丸中没食子酸、表儿茶素、鞣花酸、杨梅素、肉桂酸、丁香酚、橙黄决明素、甘松新酮、α-细辛脑和大黄酚等10...目的:建立HPLC一测多评法(quantitative analysis of multi-components by single marker,QAMS)同时测定蒙药孟根·沃斯-18丸中没食子酸、表儿茶素、鞣花酸、杨梅素、肉桂酸、丁香酚、橙黄决明素、甘松新酮、α-细辛脑和大黄酚等10种成分,并验证该方法在蒙药孟根·沃斯-18丸质量分析中应用的可行性。方法:采用Agilent Eclipse Plus C_(18)色谱柱(250 mm×4.6 mm,5μm),流动相为乙腈(A)-0.2%磷酸溶液(B),梯度洗脱(0~60 min,5%A→25%A,波长210 nm;60~80 min,25%A→36%A,波长280 nm;80~145 min,36%A→75%A,波长250 nm),流速为1.0 mL·min^(-1);柱温为40℃。以鞣花酸为内参物,建立与其他9种待测成分的相对校正因子(f_(s/i)),采用f_(s/i)计算各成分的质量分数,同时用外标法(external standard method,ESM)测定,比较2种方法测定结果,评价QAMS在蒙药孟根·沃斯-18丸中应用的准确性。结果:蒙药孟根·沃斯-18丸中没食子酸、表儿茶素、杨梅素、肉桂酸、丁香酚、橙黄决明素、甘松新酮、α-细辛脑和大黄酚9种成分的fs/i重现性良好,分别为0.2422,0.2315,0.3199,0.2565,1.9699,1.2089,1.2602,0.5605和1.2132,QAMS,ESM所得结果接近。结论:该方法简便、稳定、重复性良好,可用于孟根·沃斯-18丸的质量控制。展开更多
Coronavirus disease-19(COVID-19)is the ongoing pandemic affecting millions of people worldwide.Several vaccine candidates have been designed and developed for the causative virus,SARS-CoV-2.However high mu-tation rate...Coronavirus disease-19(COVID-19)is the ongoing pandemic affecting millions of people worldwide.Several vaccine candidates have been designed and developed for the causative virus,SARS-CoV-2.However high mu-tation rate in the viral genome and the emergence of new variants have challenged the effectiveness of these vaccines developed for previous strains.Hence,screening and identification of anti-SARS-CoV-2 agents having multi-target potency would be more impactful in the prevention of the disease.Epicatechin gallate(ECG)is a green tea polyphenol having various medicinal properties,including anti-oxidative and anti-inflammatory effects.However its role as anti-SARS-CoV-2 agent is not clear.Hence the present in silico study aims to investigate the binding potential of ECG with several proteins which are critical to SARS-CoV-2 entry and replication within the host cell.Molecular docking analyses have revealed that ECG could potentially block several amino acid residues of entry factors in host cells,spike protein,and many non-structural proteins through Hydrogen bonds and hy-drophobic interactions.Such interactions with vital proteins could inhibit SARS-CoV-2 entry and its subsequent replication into the host.Therefore,ECG could be a potential therapeutic agent for the prevention of COVID-19.However,the findings of the present study demand further validation in animal models.展开更多
基金supported by the National Key Research and Development Program of China under Grant(2022YFF1102800)the Graduate Scientific Research Innovation Project of Tianji(2022SKY109)+1 种基金the Project of Tianjin Science and Technology Program(22JCYBJC00360)the Project of Tianjin Science and Technology Program(21ZYJDJC00060)。
文摘Epicatechin(EC)was used in this study to antagonize the cognitive dysfunction caused by lead(Pb)exposure in mice.Eight-week-old male Kunming mice were treated with PbCl_(2)(20 mg/kg)and/or EC(50 mg/kg)by gavage administration for 4 weeks.Morris water maze test showed that EC could improve memory dysfunction induced by Pb.EC antagonized Ca^(2+)overload,activated Nrf2 signaling pathway and reduced the accumulation of Pb in the brain and serum,which suggested that EC might alter Pb distribution in mice.In vitro,spectroscopic analysis,potentiometric titration and docking studies were applied to inquiry into the interaction between bovine serum albumin(BSA)and Pb^(2+)in presence or absence of EC.EC was proved to chelate Pb^(2+)and reduced the interaction between BSA and Pb^(2+).In summary,EC might protect Pb-induced cognitive impairment by activating Nrf2 signaling pathway,and suppressing Pb accumulation via interference on the binding of Pb to albumin.
文摘Catechin and epicatechin are two isomeric flavonoids. Despite the vital properties highlighted by numerous scientific studies, very little data is available on the intrinsic reactivity of these compounds. To provide more details on the stability and reactivity of catechin and epicatechin, this study is performed by means of theoretical calculation methods. For this purpose, geometry optimizations and frequency calculations at the B3LYP/6-31 + G (d, p) level of theory has been carried out and Natural Bond Orbital (NBO) analysis and VEDA (Vibrational Energy Distribution Analysis). The geometric and energy parameters and NBO analysis show that catechin appears more stable than epicatechin. The hydroxyl group position on the ring C of the catechol structure represents a factor that influences this relative stability. The global and local reactivity parameters reveal that epicatechin becomes more reactive than catechin. They indicate that their hydroxyl groups correspond to their most receptive sites. Fukui indices, VEDA and acidity study establish that O28–H29 remains the most reactive.
基金This work was supported by College Students Innovation and Entrepreneurship Training Program in 2021(No.202110163003).
文摘Epicatechin gallate(ECG)is one of the polyphenolic compounds and has attracted much attention due to its various bioactivities.In this study,the neuroprotective eff ect of ECG against H_(2)O_(2)-induced oxidative injury in PC12 cells as well as the possible mechanisms were investigated.Cell viability was determined by MTT assay.The differentially expressed genes(DEGs),GO enrichment,and KEGG enrichment were analyzed to explore the mechanism of ECG against H_(2)O_(2)-induced oxidative injury by using the RNA-seq method.Finally,the change in the cell cycle was analyzed by fl ow cytometry.H_(2)O_(2)(400-1200μmol/L)inhibited the cell viability in a concentration-dependent manner.ECG(6-150μmol/L)eff ectively attenuated the H_(2)O_(2)-induced decrease in cell viability.RNA-seq analysis showed that ECG regulated 1058 coexpressed DEGs.GO enrichment analysis showed that the cellular component was the dominant group after ECG treatment.KEGG analysis showed that the cell cycle,fanconi anemia pathway,and homologous recombination were the important pathways for ECG in improving H_(2)O_(2)-induced oxidative injury and 28 coexpressed DEGs in the cell cycle pathway were summarized.Finally,cell cycle analysis also proved that ECG improved H_(2)O_(2)-induced cell cycle arrest in the G2/M phase.Our present study demonstrated that ECG attenuated H_(2)O_(2)-induced neurologic oxidative damage by multiple modulatory mechanisms at the molecular transcription level.These fi ndings provide new insights for further study of the molecular mechanism of the neuroprotection of ECG.
文摘Hypertension is a major problem worldwide. There is much evidence to suggest that reactive oxygen species (ROS) radical may play a role in the development of organ damage associated with cardiovascular disease and hypertension. (-)Epicatechin, a member of tea catechins belonging to flavonoid group, is known to be a potent anti-oxidant. The study has been undertaken to evaluate the effect of (-)epicatechin on markers of oxidative stress: reduced glutathione (GSH) and membrane sulfhydryl (-SH) groups in erythrocytes from hypertensive patients. The effect of (-)epicatechin was also compared with a known anti-oxidant L-ascorbic acid. The erythrocyte intracellular GSH content and membrane -SH group content were significantly (P<0.01) decreased in hypertensive subjects. In vitro incubation with (-)epicatechin caused an increase in GSH and -SH content, the effect was more pronounced in hypertensive erythrocytes. Similar results were obtained with L-ascorbic acid. The observed decrease in the level of GSH and -SH groups in hypertension is an indicator of oxidative stress condition. Observation of an increase in red cell GSH content and the protection of membrane -SH group oxidation by (-)epicatechin in hypertensive subjects is a convincing reason to suggest that high dietary intake of foods rich in catechins may help to reduce oxidative stress and concomitant free radical damage in hypertensive patients.
基金financially supported by the National Natural Science Foundation of China(21175041)the National Basic Research Program of China(2012CB910602)
文摘The interaction between BSA and epicatechin was studied using fluorescence quenching titrations combined with trilinear decomposition method and excitation-emission matrix(EEM)fluorescence.The resolved spectra were highly similar with the actual ones which indicated that the resolved results were reliable.The relevant parameters of the binding process were obtained by quantifying each substance in the complicated mixtures in situ.The quenching was static quenching,epicatechin had a weak interaction with BSA and the binding site was one.The total concentration and the free concentration of quenchers had different effect on the system.The results demonstrated that the method exploited in this article is a useful tool to investigate complicated interactions,avoiding complicated pretreatment and simplify experimental procedure.
文摘目的:建立HPLC一测多评法(quantitative analysis of multi-components by single marker,QAMS)同时测定蒙药孟根·沃斯-18丸中没食子酸、表儿茶素、鞣花酸、杨梅素、肉桂酸、丁香酚、橙黄决明素、甘松新酮、α-细辛脑和大黄酚等10种成分,并验证该方法在蒙药孟根·沃斯-18丸质量分析中应用的可行性。方法:采用Agilent Eclipse Plus C_(18)色谱柱(250 mm×4.6 mm,5μm),流动相为乙腈(A)-0.2%磷酸溶液(B),梯度洗脱(0~60 min,5%A→25%A,波长210 nm;60~80 min,25%A→36%A,波长280 nm;80~145 min,36%A→75%A,波长250 nm),流速为1.0 mL·min^(-1);柱温为40℃。以鞣花酸为内参物,建立与其他9种待测成分的相对校正因子(f_(s/i)),采用f_(s/i)计算各成分的质量分数,同时用外标法(external standard method,ESM)测定,比较2种方法测定结果,评价QAMS在蒙药孟根·沃斯-18丸中应用的准确性。结果:蒙药孟根·沃斯-18丸中没食子酸、表儿茶素、杨梅素、肉桂酸、丁香酚、橙黄决明素、甘松新酮、α-细辛脑和大黄酚9种成分的fs/i重现性良好,分别为0.2422,0.2315,0.3199,0.2565,1.9699,1.2089,1.2602,0.5605和1.2132,QAMS,ESM所得结果接近。结论:该方法简便、稳定、重复性良好,可用于孟根·沃斯-18丸的质量控制。
文摘Coronavirus disease-19(COVID-19)is the ongoing pandemic affecting millions of people worldwide.Several vaccine candidates have been designed and developed for the causative virus,SARS-CoV-2.However high mu-tation rate in the viral genome and the emergence of new variants have challenged the effectiveness of these vaccines developed for previous strains.Hence,screening and identification of anti-SARS-CoV-2 agents having multi-target potency would be more impactful in the prevention of the disease.Epicatechin gallate(ECG)is a green tea polyphenol having various medicinal properties,including anti-oxidative and anti-inflammatory effects.However its role as anti-SARS-CoV-2 agent is not clear.Hence the present in silico study aims to investigate the binding potential of ECG with several proteins which are critical to SARS-CoV-2 entry and replication within the host cell.Molecular docking analyses have revealed that ECG could potentially block several amino acid residues of entry factors in host cells,spike protein,and many non-structural proteins through Hydrogen bonds and hy-drophobic interactions.Such interactions with vital proteins could inhibit SARS-CoV-2 entry and its subsequent replication into the host.Therefore,ECG could be a potential therapeutic agent for the prevention of COVID-19.However,the findings of the present study demand further validation in animal models.
