This article aims to explain the inhibitory mechanism of thinned-young apple polyphenols(YAP)toward Fusobacterium nucleatum(F.nucleatum),Porphyromonas gingivalis(P.gingivalis)and Prevotella intermedia(P.intermedia).YA...This article aims to explain the inhibitory mechanism of thinned-young apple polyphenols(YAP)toward Fusobacterium nucleatum(F.nucleatum),Porphyromonas gingivalis(P.gingivalis)and Prevotella intermedia(P.intermedia).YAP has optimal antibacterial concentration against F.nucleatum(10.00 mg/mL),P.gingivalis(8.00 mg/mL)and P.intermedia(8.00 mg/mL),with viability of 47.97%,38.01%and 36.94%,respectively.Scanning electron microscopy(SEM)and confocal laser scanning microscopy(CLSM)observation revealed that YAP could cause the morphological changes of the halitosis-related bacterial cells and induce cell apoptosis.With the increase of YAP treatment concentrations,the permeability of the outer membranes(OM)and inner membranes(IM)of halitosis-related bacteria dramatically increased,resulting in the release of proteins and nucleic acids.In addition,bacterial cell membrane potential(MP)decreased after exposure to YAP.The results of this study provide new antibacterial agents for halitosis-related bacteria and find a new way for the development of thinned-young apples.展开更多
What is known about this topic?Dengue fever is an acute febrile illness caused by four types of dengue virus(DENV 1–4),and is a mosquitoborne infectious disease.The incidence of dengue has increased dramatically arou...What is known about this topic?Dengue fever is an acute febrile illness caused by four types of dengue virus(DENV 1–4),and is a mosquitoborne infectious disease.The incidence of dengue has increased dramatically around the world in recent decades.An estimated of 3.9 billion people in 128 countries are at risk of infection with dengue viruses,70%of whom are in Asia.In 2017,the first local infections of dengue virus(DENV-2)in Jiangxi Province was reported in Zhanggong District,Ganzhou City.What is added by this report?From August to September 2019,the first dengue outbreak happened in Xin’gan County,where 81 local dengue fever cases were reported,35 were laboratoryconfirmed cases,and 46 were clinically-diagnosed cases;all cases were dengue virus type 1.The DENV-virus strains isolated from the cases of Xin’gan County were close to the strains isolated in Singapore(MF033254|25657|Singapore|2016)and Henan(MK905537|He nan201903|China:Henan Province|2019).What are the implications for public health practice?The outbreak might have been caused by imported cases or covert infections.The outbreak in Xin’gan County indicated that more proactive countermeasures should be taken during the dengue epidemic period such as intensifying surveillance for dengue cases,virus serotype,and Aedes vector density and strengthening cooperation with customs and tourism departments.Moreover,the outbreak should prompt training in medical institutions and improved ability for doctor’s to diagnose dengue fever,which is very important for early detection of dengue cases and taking preventive measures.展开更多
Although the catabolic pathway of some flavonoids in the human colon has been elucidated,knowledge of related gut microbes and responsible enzymes is still limited.In this study,a phloretin hydrolase gene(phy)from Fla...Although the catabolic pathway of some flavonoids in the human colon has been elucidated,knowledge of related gut microbes and responsible enzymes is still limited.In this study,a phloretin hydrolase gene(phy)from Flavonifractor plautii(F.plautii)was synthesized and heterologously expressed in Escherichia coli BL21(E.coli BL 21).Phloretin hydrolase(PHY)was purified from cell extracts of recombinant E.coli BL21,and PHY's molecular weight was about 32 kDa.The purified PHY effectively cleaved phloretin into 3-(4-hydroxyphenyl)propionic acid(HPPA)and phloroglucinol(PG).PHY's kinetic parameters were determined:Km was 2.8×10−3±0.4 mM and Vmax was 411.2±7.1 U/mg.Besides,PHY's optimal temperature and pH were 50°C and 7.5,respectively,and PHY exhibited 75%activity after 5 h at 50°C.Furthermore,PHY's activity was inhibited in the presence of Ba2+,Cu2+,and Fe2+,while Mg2+slightly elevated PHY's activity.Finally,the catalytic model between phloretin and PHY was built using molecular docking,and PHY's conformational changes were further demonstrated through the multispectral techniques.This study is conducive to understanding phloretin metabolism in the colon and adding a valuable source of PHY for food industry application.展开更多
基金supported by the National Natural Science Foundation of China(No.31701563)the Key Research and Development Program of Shaanxi Province(No.2019NY-124)+1 种基金Ministry of Education(XGZX 2021G08)the Fundamental Research Funds for the Central Universities at Shaanxi Normal University(1301031057).
文摘This article aims to explain the inhibitory mechanism of thinned-young apple polyphenols(YAP)toward Fusobacterium nucleatum(F.nucleatum),Porphyromonas gingivalis(P.gingivalis)and Prevotella intermedia(P.intermedia).YAP has optimal antibacterial concentration against F.nucleatum(10.00 mg/mL),P.gingivalis(8.00 mg/mL)and P.intermedia(8.00 mg/mL),with viability of 47.97%,38.01%and 36.94%,respectively.Scanning electron microscopy(SEM)and confocal laser scanning microscopy(CLSM)observation revealed that YAP could cause the morphological changes of the halitosis-related bacterial cells and induce cell apoptosis.With the increase of YAP treatment concentrations,the permeability of the outer membranes(OM)and inner membranes(IM)of halitosis-related bacteria dramatically increased,resulting in the release of proteins and nucleic acids.In addition,bacterial cell membrane potential(MP)decreased after exposure to YAP.The results of this study provide new antibacterial agents for halitosis-related bacteria and find a new way for the development of thinned-young apples.
文摘What is known about this topic?Dengue fever is an acute febrile illness caused by four types of dengue virus(DENV 1–4),and is a mosquitoborne infectious disease.The incidence of dengue has increased dramatically around the world in recent decades.An estimated of 3.9 billion people in 128 countries are at risk of infection with dengue viruses,70%of whom are in Asia.In 2017,the first local infections of dengue virus(DENV-2)in Jiangxi Province was reported in Zhanggong District,Ganzhou City.What is added by this report?From August to September 2019,the first dengue outbreak happened in Xin’gan County,where 81 local dengue fever cases were reported,35 were laboratoryconfirmed cases,and 46 were clinically-diagnosed cases;all cases were dengue virus type 1.The DENV-virus strains isolated from the cases of Xin’gan County were close to the strains isolated in Singapore(MF033254|25657|Singapore|2016)and Henan(MK905537|He nan201903|China:Henan Province|2019).What are the implications for public health practice?The outbreak might have been caused by imported cases or covert infections.The outbreak in Xin’gan County indicated that more proactive countermeasures should be taken during the dengue epidemic period such as intensifying surveillance for dengue cases,virus serotype,and Aedes vector density and strengthening cooperation with customs and tourism departments.Moreover,the outbreak should prompt training in medical institutions and improved ability for doctor’s to diagnose dengue fever,which is very important for early detection of dengue cases and taking preventive measures.
基金supported by the National Natural Science Foundation(31972089)the 2020 Team Innovation Project from the Fundamental Scientific Research Special Capital Fund of the National Universities,China(GK202001008).
文摘Although the catabolic pathway of some flavonoids in the human colon has been elucidated,knowledge of related gut microbes and responsible enzymes is still limited.In this study,a phloretin hydrolase gene(phy)from Flavonifractor plautii(F.plautii)was synthesized and heterologously expressed in Escherichia coli BL21(E.coli BL 21).Phloretin hydrolase(PHY)was purified from cell extracts of recombinant E.coli BL21,and PHY's molecular weight was about 32 kDa.The purified PHY effectively cleaved phloretin into 3-(4-hydroxyphenyl)propionic acid(HPPA)and phloroglucinol(PG).PHY's kinetic parameters were determined:Km was 2.8×10−3±0.4 mM and Vmax was 411.2±7.1 U/mg.Besides,PHY's optimal temperature and pH were 50°C and 7.5,respectively,and PHY exhibited 75%activity after 5 h at 50°C.Furthermore,PHY's activity was inhibited in the presence of Ba2+,Cu2+,and Fe2+,while Mg2+slightly elevated PHY's activity.Finally,the catalytic model between phloretin and PHY was built using molecular docking,and PHY's conformational changes were further demonstrated through the multispectral techniques.This study is conducive to understanding phloretin metabolism in the colon and adding a valuable source of PHY for food industry application.
