A large amount of free radicals can be generated in human body during metabolic process.These free radicals can result in oxidative stress and homeostasis imbalance,even some chronic diseases and cancers if they are n...A large amount of free radicals can be generated in human body during metabolic process.These free radicals can result in oxidative stress and homeostasis imbalance,even some chronic diseases and cancers if they are not promptly removed.Currently,many studies devote to exploring and utilizing natural antioxidants to remove excessive free radicals in human body,thus realizing the prevention and treatment of diseases.In the present study,the major species of natural antioxidants in foods that are benefit for the prevention and treatments of diseases have been summarized.Meanwhile,the research progress and future development have also been proposed.All of these studies,on the one hand,can provide a theoretical basis for the development of drugs and healthy foods;on the other hand,can offer novel development ideas for food industry,especially for food additive industry.展开更多
pRST98 is a chimeric plasmid isolated from Salmonella enterica serovar Typhi(S.typhi)that mediates the functions of drug resistance and virulence.Previously,we reported that Salmonella plasmid virulence(spv)genes were...pRST98 is a chimeric plasmid isolated from Salmonella enterica serovar Typhi(S.typhi)that mediates the functions of drug resistance and virulence.Previously,we reported that Salmonella plasmid virulence(spv)genes were present in S.typhi.In our current study,we investigated whether plasmid pRST98 exhibits significant cytotoxicity in macrophages.pRST98 was transferred into the avirulent Salmonella enterica serovar Typhimurium(S.typhimurium)strain RIA to create the transconjugant pRST98/RIA.The standard S.typhimurium virulent strain SR-11,which carries a 100-kb virulence plasmid,was used as a positive control.The bacterial strains were incubated with a murine macrophage-like cell line(J774A.1)in vitro.Apoptosis of J774A.1 cells was examined by electron microscopy and flow cytometry after annexin-V/propidium iodide labeling,and the survival of Salmonella strains in J774A.1 cells was determined.Results showed that macrophages infected with strain pRST98/RIA displayed greater levels of apoptosis than those infected with RIA and that pRST98 may increase bacterial survival in macrophages.Further studies showed that the pRST98-induced death of macrophages was associated with the loss of mitochondrial membrane potential and that pRST98 may activate caspase-9 and then caspase-3.The research data indicate that the virulence of bacteria that contain the pRST98 plasmid is enhanced;the presence of this plasmid increases the survival of the bacterial pathogen and acts through the mitochondrial pathway to mediate macrophage apoptosis.展开更多
文摘A large amount of free radicals can be generated in human body during metabolic process.These free radicals can result in oxidative stress and homeostasis imbalance,even some chronic diseases and cancers if they are not promptly removed.Currently,many studies devote to exploring and utilizing natural antioxidants to remove excessive free radicals in human body,thus realizing the prevention and treatment of diseases.In the present study,the major species of natural antioxidants in foods that are benefit for the prevention and treatments of diseases have been summarized.Meanwhile,the research progress and future development have also been proposed.All of these studies,on the one hand,can provide a theoretical basis for the development of drugs and healthy foods;on the other hand,can offer novel development ideas for food industry,especially for food additive industry.
基金supported by the Natural Science Foundation of China(No.30972768)the Special and General Postdoctoral Science Foundation of China(No.200902529 and No.20080430178)+1 种基金the Natural Science Foundation of Jiangsu High Education Institute of China(No.08KJB310009)the Social Development Science Foundation of Suzhou City of China(No.SS08025).
文摘pRST98 is a chimeric plasmid isolated from Salmonella enterica serovar Typhi(S.typhi)that mediates the functions of drug resistance and virulence.Previously,we reported that Salmonella plasmid virulence(spv)genes were present in S.typhi.In our current study,we investigated whether plasmid pRST98 exhibits significant cytotoxicity in macrophages.pRST98 was transferred into the avirulent Salmonella enterica serovar Typhimurium(S.typhimurium)strain RIA to create the transconjugant pRST98/RIA.The standard S.typhimurium virulent strain SR-11,which carries a 100-kb virulence plasmid,was used as a positive control.The bacterial strains were incubated with a murine macrophage-like cell line(J774A.1)in vitro.Apoptosis of J774A.1 cells was examined by electron microscopy and flow cytometry after annexin-V/propidium iodide labeling,and the survival of Salmonella strains in J774A.1 cells was determined.Results showed that macrophages infected with strain pRST98/RIA displayed greater levels of apoptosis than those infected with RIA and that pRST98 may increase bacterial survival in macrophages.Further studies showed that the pRST98-induced death of macrophages was associated with the loss of mitochondrial membrane potential and that pRST98 may activate caspase-9 and then caspase-3.The research data indicate that the virulence of bacteria that contain the pRST98 plasmid is enhanced;the presence of this plasmid increases the survival of the bacterial pathogen and acts through the mitochondrial pathway to mediate macrophage apoptosis.
