The efficient adsorption of radioactive iodine(^(129)I and^(131)I)as nuclear waste is of great importance.Polymer nanocomposites consist of metal-organic frameworks(MOFs)developing for various pollutions sorption and ...The efficient adsorption of radioactive iodine(^(129)I and^(131)I)as nuclear waste is of great importance.Polymer nanocomposites consist of metal-organic frameworks(MOFs)developing for various pollutions sorption and separation have attracted much attention.This study reports the fabrication of magnetic polyacrylonitrile(PAN)/zeolitic imidazolate frameworks(ZIF-8)nanocomposites,PAN/ZIF-8(x%)/Fe_(3)O_(4),x=30 and 50,as iodine capture adsorbents.The PAN/ZIF-8(x%)/Fe_(3)O_(4)nanocomposite beads were fabricated via the phase inversion method,and their potential for iodine capture and separation in solution and vapor was investigated through UV-vis and weighing methods,respectively.Also,antibacterial activity of the as-prepared beads was assessed against E.coil and S.aureus.The as-fabricated compounds were studied by various techniques such as Fourier-transform infrared,X-ray diffraction,scanning electron microscope,energy-dispersive X-ray spectroscopy mapping,transmission electron microscope,N_(2)adsorption isotherm,and vibrating sample magnetometer.The iodine capture results showed that the efficiency of nanocomposites is remarkably higher than the pure PAN beads.Additionally,the asprepared nanocomposite adsorbents displayed higher capture capacities for iodine vapor(1524-4345mg·g^(-1))than iodine solution(187-295 mg·g^(-1)).The as-obtained magnetic nanocomposites can be successfully separated from polluted media by simple filtration or an external magnet,regenerated through washing with ethanol,and reused.Fast capturing,high sorption capacity,rapid separation,and good reusability make the PAN/ZIF-8(x%)/Fe_(3)O_(4)nanocomposites highly effective adsorbents for the separation of iodine from wastewater.Additionally,PAN/ZIF-8(50%)/Fe_(3)O_(4)bead can be considered as a potential new antibacterial agent for water and wastewater treatment.展开更多
Objective:To guide for selection of plants with antibacterial activity for further phytochemical works on the isolation and identification of the active compounds.Methods:Ethanolic extracts of 3 species from Malvaceae...Objective:To guide for selection of plants with antibacterial activity for further phytochemical works on the isolation and identification of the active compounds.Methods:Ethanolic extracts of 3 species from Malvaceae family were evaluated by agar disc diffusion method for antibacterial activity against some gram-positive and gram-negative bacteria(Pseudomonas aeruginosa,Listeria monocytogenes,Staphylococcus epidermidis.Staphylococcus aureus, Klebsiella pneumoniae.Salmonella typhi,Bacillus cereus.Bacillus anthracis,Escherichia coli and Streptococcus pyogenes).The extracts were obtained from aerial parts of Hibiscus rosa(H. rosa)-sinensis(leaf and flower),Alcea rosea(A.rosea) L.(leaf and flower) and Malva neglecta(M. neglecta) Wallr(flower).Results:These extracts had inhibitory effects at different concentrations (0.05,0.10,0.20 and 0.40 g/mL) against above mentioned bacteria.Escherichia coli was the most resistant strain.The highest inhibitory zone was showed by ethanolic extract of M.neglecta against Staphylococcus epidermidis(22 mm) and followed by ethanolic extract from flower of H.rosa against Staphylococcus epidermidis and Staphylococcus aureus(20 mm).The Minimum Inhibitory Concentration(MIC) and Minimum Bactericidal Concentration(MBC) values against Staphylococcus epidermidis were equal(M1C=MBC=5 mg/mL for M.neglecta extract and for H. rosa extract MIC=MBC=20 mg/mL).Conclusions:These findings suggest that these native plants have good antibacterial properties that can be used for infection control and treatment and could also be as new source for antibiotics discovery and infection treatment.展开更多
Chromolaena odorata L (Asteraceae) is a bad invasive plant, found in the humid tropics and sub-tropics worldwide. It is used against dysentery, diarrhea, malaria, wound healing, headache and toothache in traditional m...Chromolaena odorata L (Asteraceae) is a bad invasive plant, found in the humid tropics and sub-tropics worldwide. It is used against dysentery, diarrhea, malaria, wound healing, headache and toothache in traditional medicine. In the present study, we investigated the antibacterial activities of different leaves extracts of Chromolaena odorata L. (cyclohexane, dichloromethane, ethyl acetate and butanol) against four clinical diarrheal strains (Klebsiella oxytoca, Salmonella enterica, Shigella sonnei and Vibrio cholera). We demonstrated that C. odorata leaves extracts show an antibacterial activity between 0.156 and 1.25 mg/mL. Bioassay-guided chromatography by bioautography with iodonitrotetrazolium-based colorimetric assay allowed the isolation and identification of two active compounds. After the combination of RP-HPLC, mass spectrometry analysis, 1D and 2D-NMR spectroscopy, we isolated and characterized two active molecules corresponding to 3’,4’,5,6,7-Pentamethoxyflavone (Sinensetin) and4’,5,6,7-Tetramethoxyflavone (Scutellareintetramethyl ether).展开更多
Dynamic changes in mRNA expressions of liver tissue apoptosis-promoting genes Fas and Bax and apoptosis-inhibiting gene Bcl-2 of vibrio vulnificus sepsis rats were detected and the effects of antibacterial agents were...Dynamic changes in mRNA expressions of liver tissue apoptosis-promoting genes Fas and Bax and apoptosis-inhibiting gene Bcl-2 of vibrio vulnificus sepsis rats were detected and the effects of antibacterial agents were examined. The rat model with Vibrio vulnificus sepsis (VV group) was established and some of the Vibrio vulnificus sepsis rats were treated with antibacterial agents (AA group). The mRNA expressions of Fas, Bax and Bcl-2 were measured by reverse transcription polymerase chain reaction (RT-PCR). As compared with normal control group (NC group), the expressions of Fas and Bax mRNA in liver tissue at all different time points in VV group were increased significantly (P<0.05), and the highest levels of Fas and Bax mRNA expressions were 6 and 12 h after the infection, respectively. At the same time, the expression of Bcl-2 mRNA in liver tissue at all different time points in VV group were decreased significantly (P<0.05), and the lowest level of Bcl-2 mRNA expression appeared 2 h after the infection. The mRNA expressions of Bcl-2 in liver tissue 9 and 12 h after the infection in AA group were increased significantly (P<0.05) compared with NC group, while the expressions of Fas and Bax mRNA were not significantly different from those of NC group. Compared with VV group, the expression of Fas mRNA in AA group was decreased (P<0.05) and Bax mRNA was decreased significantly 12 and 16 h after the infection (P<0.05), while the expressions of Bcl-2 mRNA were increased significantly 9, 12 and 16 h after the infection (P<0.05). It is concluded that the mRNA expressions of liver tissue apoptosis-promoting genes Fas and Bax were increased remarkably in vibrio vulnificus sepsis rats, whereas the expression of apoptosis-inhibiting gene Bcl-2 mRNA was decreased obviously in sepsis rats in early stage. The treatment with cefoperazone sodium and levofloxacin lactate could inhibit the expression of Fas mRNA and Bax mRNA and enhance the expression of Bcl-2 mRNA at the same time.展开更多
Falsified antibacterial agents continue to pose serious public health problems around the world. They are notably responsible for resistance emergence in the treatment of infectious diseases that can lead to death. Th...Falsified antibacterial agents continue to pose serious public health problems around the world. They are notably responsible for resistance emergence in the treatment of infectious diseases that can lead to death. The aim of this study was to summarize the literature on the methods developed and validated to detect poor quality antibacterial agents in order to assess the impact of these available methods in the fighting against Counterfeit/substandard medicines. Thus, studies published in the time from January 2000 to July 2017, were accessible via Google Scholar and Pubmed and allowed to analyze 41 papers. The majority (30) of developed and validated methods concerned LC methods, 9 regarded UV/V is spectrophotometry and two studies simultaneously developed both methods. Antibacterial agents belonging to beta-lactams group were the most concerned by the methods developed and validated (39%), followed by quinolones (18%) and macrolides (12%). Regarding active ingredients, amoxicillin (12%) was the most concerned by the development and validation methods. In spite of several available methods to detect substandard drugs, antibacterial agents for which methods were developed and validated were the most concerned by worldwide detected non-conformities. The fight against this scourge should not be only limited by their detection, but it also requires an effective involvement of different actors notably: health authorities, international organizations, pharmaceutical industries etc.展开更多
Some antibacterial agents have been shown to neutralize the biological properties of bacterial lipopolysaccharide (LPS). The aim of this study was to eluci- date the role of gentamicin, tobramycin, imipenem, tigecycli...Some antibacterial agents have been shown to neutralize the biological properties of bacterial lipopolysaccharide (LPS). The aim of this study was to eluci- date the role of gentamicin, tobramycin, imipenem, tigecycline, and isoniazid in affecting the production of nitric oxide (NO) induced by LPS in mice. Groups of mice were injected intraperitoneally with LPS alone, antibacterial agent alone, or LPS in combination with an antibacterial agent. Serum NO levels were determined at 1, 3, 6 and 9 hours post-injection using the Griess reagent method. Thin layer chroma- tography was performed to determine if antibacterial agent—LPS interaction had occurred. All the antibacterial agents suppressed NO production. More- over, LPS-induced production of NO was suppressed by all the antibacterial agents, tobramycin and tigecycline being the most effective at 9 hours post-injection. Blocking of any of the stages leading to NO production by the antibacterial agents is suggested. Moreover, thin layer chromatograms obtained are suggestive of LPS-antibacterial agent interactions.展开更多
A highly practical and efficient preparation of 6-methy-4H-thiochromene and 7-methyl-thiochromene[2,3-d]pyrimidine derivatives was developed via a multi-component reaction of 3-methyl-thiophenol (1), aldehydes (2), an...A highly practical and efficient preparation of 6-methy-4H-thiochromene and 7-methyl-thiochromene[2,3-d]pyrimidine derivatives was developed via a multi-component reaction of 3-methyl-thiophenol (1), aldehydes (2), and malononitrile (3). A series of pyrimidine nucleoside, thiochromene[2,3-d]pyrimidine and thiochromene[2,3-d]pyrimidine-10-sulfone was efficiently obtained. These hybrid compounds were evaluated as potential antibacterial and anticancer agents and showed encouraging biological activities. Some of these derivatives showed broad-spectrum antitumour activity against the nine tumour subpanels tested, and demonstrated significant activity in the in vitro antitumour screening expressed by MG-MID log10GI50 value of -4.55, -4.67 and -4.73 of compounds 9a, 9b and 9c, respectively.展开更多
A low temperature preparation of nano TiO2 using sol-gel method was proposed. The antibacterial properties of the treatment solution and the treated cotton fabrics obtained via a dip-padding process were evaluated. XR...A low temperature preparation of nano TiO2 using sol-gel method was proposed. The antibacterial properties of the treatment solution and the treated cotton fabrics obtained via a dip-padding process were evaluated. XRD pattern shows that the nano TiO2 produced is an anatase phase. Aqueous nano-dispersion of the nano TiO2 exhibites positive results as an antibacterial finishing agent for cotton fabrics. The treatment solution possesses antibacterial rates of over 92% and 88.9% against Escherichia coli and Bacillus subtilis,respectively. The treated fabrics are slightly downgraded but still maintained over 89% and 83% of reduction towards the same bacteria. After washing for 50 times,the antibacterial performances of the treated fabric still remains at a relatively high level,indicating the durable characteristic of nano TiO2 treatment.展开更多
A series of monochlorotriazine reactive antibacterial agents were synthesised by using 2,4,4’ - trichloro -2’ - hydroxydiphenyl ether as a starting material. The spectrum analyses (UV and MS) and elementary analy-se...A series of monochlorotriazine reactive antibacterial agents were synthesised by using 2,4,4’ - trichloro -2’ - hydroxydiphenyl ether as a starting material. The spectrum analyses (UV and MS) and elementary analy-ses were also carried out. These antibacterial agents can be used as the bacteria - resistance finishing agents of the cellulose fabrics. The treated fabrics possess excellent antibacterial activity and durable wash fastness. For ex-ample , the percentages of bacterial reduction of the fab-ric finished with reactive antibacterial agent 2RSDP are 98.5%, 98. 86% and 96.67% for Staphylococcus au-reus, Escherichia coli and Pseudomonas aeruginose re-spectively. After more than 100 times of washing at 60°C, the antibacterial activity still retains at a level of about 90% of the original. The relationships between the molecular structures of the reactive antibacterial finish-ing agents and their antibacterial activities are discussed.展开更多
The diverse and large-scale application of disinfectants posed potential health risks and caused ecological damage during the 2019-nCoV pandemic,thereby increasing the demands for the development of disinfectants base...The diverse and large-scale application of disinfectants posed potential health risks and caused ecological damage during the 2019-nCoV pandemic,thereby increasing the demands for the development of disinfectants based on natural products,with low health risks and low aquatic toxicity.In the present study,a few natural naphthoquinones and their derivatives bearing the 1,4-naphthoquinone skeleton were synthesized,and their antibacterial activity against selected bacterial strains was evaluated.In vitro antibacterial activities of the compounds were investigated against Escherichia coli and Staphylococcus aureus.Under the minimum inhibitory concentration(MIC)of≤0.125μmol/L for juglone(1a),5,8-dimethoxy-1,4-naphthoquinone(1f),and 7-methyl-5-acetoxy-1,4-naphthoquinone(3),a strong antibacterial activity against S.aureus was observed.All 1,4-naphthoquinone derivatives exhibited a strong antibacterial activity,with MIC values ranging between 15.625 and 500μmol/Land ECso values rangingbetween10.56 and248.42μmol/L.Most of the synthesized compounds exhibited strong antibacterial activities against S.aureus.Among these compounds,juglone(la)showed the strongest antibacterial activity.The results from mechanistic investigations indicated that juglone,a natural naphthoquinone,caused cell death by inducing reactive oxygen species production in bacterial cells,leading to DNA damage.In addition,juglone could reduce the self-repair ability of bacterial DNA by inhibiting RecA expression.In addition to having a potent antibacterial activity,juglone exhibited low cytotoxicity in cell-based investigations.In conclusion,juglone is a strong antibacterial agent with low toxicity,indicating that its application as a bactericidal agent may be associated with low health risks and aquatic toxicity.展开更多
Cu_(2-x)S nanostructures have been intensively studied as outstanding chemodynamic therapy(CDT)and good photothermal therapy(PTT)antibacterial agents due to their highly efficient Cu(Ⅰ)-initiated Fenton-like catalyti...Cu_(2-x)S nanostructures have been intensively studied as outstanding chemodynamic therapy(CDT)and good photothermal therapy(PTT)antibacterial agents due to their highly efficient Cu(Ⅰ)-initiated Fenton-like catalytic activity and good photothermal conversion property.However,they still suffer from shortage of Cu(Ⅰ)supply in the long-term and comparatively low inherent photothermal conversion efficiency.Herein,we constructed a self-enhanced synergistic PTT/CDT nanoplatform(Cu_(1.94)S@MPN)by coating Cu_(1.94)S nanoparticles with Fe(Ⅲ)/tannic acid based metal-polyphenol networks(MPN).Activated by the acidic bacterial infection microenvironment,Cu_(1.94)S@MPN could be decomposed to continuously release Cu(Ⅱ),Fe(Ⅲ)ions and tannic acid.As the result of tannic acid-involved Cu and Fe redox cycling,Cu(Ⅰ)/Fe(Ⅱ)-rich CDT could be achieved through the highly accelerated catalytic Fenton/Fenton-like reactions.More importantly,experimental results demonstrated that Cu_(1.94)S@MPN exhibited both excellent photothermal antibacterial and photothermal-enhanced CDT properties to eradicate bacteria in vitro and in vivo.Overall,this novel nanotherapeutics has great potential to become a clinic candidate for anti-infective therapy in future.展开更多
Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity ag...Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.展开更多
Starting from sissotrin (1), a natural isoflavonoid isolated from Trifolium baccarinii (Fabaceae), one new semisynthetic derivative, 6-nitrobiochanin A (1b) and two known derivatives, 8-nitrobiochanin A (1a) and 2&quo...Starting from sissotrin (1), a natural isoflavonoid isolated from Trifolium baccarinii (Fabaceae), one new semisynthetic derivative, 6-nitrobiochanin A (1b) and two known derivatives, 8-nitrobiochanin A (1a) and 2",3",4",6"-tetraacetylsissotrin (1c) have been obtained after performing nitration and acetylation reactions. Their structures were assigned after interpretation of their spectrometric (HR-ESI-MS) and spectroscopic (NMR 1D and 2D) data and by comparison with those reported in the literature. The substrate as well as the semisynthetic derivatives were evaluated for their antibacterial activities against six strains. The results reveal that they are inactive or weakly active on the strains tested with the exception of 8-nitrobiochanin A (1a) which showed moderate activity (MIC = 62.5 μg∙mL<sup>−1</sup>) on Staphylococcus aureus ATCC 43300.展开更多
Long non-coding RNAs(lncRNAs)function as key modulators in mammalian immunity,particularly due to their involvement in lncRNA-mediated competitive endogenous RNA(ceRNA)crosstalk.Despite their recognized significance i...Long non-coding RNAs(lncRNAs)function as key modulators in mammalian immunity,particularly due to their involvement in lncRNA-mediated competitive endogenous RNA(ceRNA)crosstalk.Despite their recognized significance in mammals,research on lncRNAs in lower vertebrates remains limited.In the present study,we characterized the first immune-related lncRNA(pol-lnc78)in the teleost Japanese flounder(Paralichthys olivaceus).Results indicated that pol-lnc78 acted as a ceRNA for pol-miR-n199-3p to target the sterile alpha and armadillo motif-containing protein(SARM),the fifth discovered member of the Toll/interleukin 1(IL-1)receptor(TIR)adaptor family.This ceRNA network regulated the antibacterial responses of flounder via the Toll-like receptor(TLR)signaling pathway.Specifically,SARM acted as a negative regulator and exacerbated bacterial infection by inhibiting the expression of inflammatory cytokines IL-1βand tumor necrosis factor-α(TNF-α).Pol-miR-n199-3p reduced SARM expression by specifically interacting with the 3’untranslated region(UTR),thereby promoting SARM-dependent inflammatory cytokine expression and protecting the host against bacterial dissemination.Furthermore,pol-lnc78 sponged pol-miR-n199-3p to ameliorate the inhibition of SARM expression.During infection,the negative regulators pol-lnc78 and SARM were significantly down-regulated,while pol-miR-n199-3p was significantly up-regulated,thus favoring host antibacterial defense.These findings provide novel insights into the mechanisms underlying fish immunity and open new horizons to better understand ceRNA crosstalk in lower vertebrates.展开更多
基金financial support(SCU.SC1400.29011)from the Shahid Chamran University of Ahvaz。
文摘The efficient adsorption of radioactive iodine(^(129)I and^(131)I)as nuclear waste is of great importance.Polymer nanocomposites consist of metal-organic frameworks(MOFs)developing for various pollutions sorption and separation have attracted much attention.This study reports the fabrication of magnetic polyacrylonitrile(PAN)/zeolitic imidazolate frameworks(ZIF-8)nanocomposites,PAN/ZIF-8(x%)/Fe_(3)O_(4),x=30 and 50,as iodine capture adsorbents.The PAN/ZIF-8(x%)/Fe_(3)O_(4)nanocomposite beads were fabricated via the phase inversion method,and their potential for iodine capture and separation in solution and vapor was investigated through UV-vis and weighing methods,respectively.Also,antibacterial activity of the as-prepared beads was assessed against E.coil and S.aureus.The as-fabricated compounds were studied by various techniques such as Fourier-transform infrared,X-ray diffraction,scanning electron microscope,energy-dispersive X-ray spectroscopy mapping,transmission electron microscope,N_(2)adsorption isotherm,and vibrating sample magnetometer.The iodine capture results showed that the efficiency of nanocomposites is remarkably higher than the pure PAN beads.Additionally,the asprepared nanocomposite adsorbents displayed higher capture capacities for iodine vapor(1524-4345mg·g^(-1))than iodine solution(187-295 mg·g^(-1)).The as-obtained magnetic nanocomposites can be successfully separated from polluted media by simple filtration or an external magnet,regenerated through washing with ethanol,and reused.Fast capturing,high sorption capacity,rapid separation,and good reusability make the PAN/ZIF-8(x%)/Fe_(3)O_(4)nanocomposites highly effective adsorbents for the separation of iodine from wastewater.Additionally,PAN/ZIF-8(50%)/Fe_(3)O_(4)bead can be considered as a potential new antibacterial agent for water and wastewater treatment.
基金Shahid Chamran University for preparing research grant
文摘Objective:To guide for selection of plants with antibacterial activity for further phytochemical works on the isolation and identification of the active compounds.Methods:Ethanolic extracts of 3 species from Malvaceae family were evaluated by agar disc diffusion method for antibacterial activity against some gram-positive and gram-negative bacteria(Pseudomonas aeruginosa,Listeria monocytogenes,Staphylococcus epidermidis.Staphylococcus aureus, Klebsiella pneumoniae.Salmonella typhi,Bacillus cereus.Bacillus anthracis,Escherichia coli and Streptococcus pyogenes).The extracts were obtained from aerial parts of Hibiscus rosa(H. rosa)-sinensis(leaf and flower),Alcea rosea(A.rosea) L.(leaf and flower) and Malva neglecta(M. neglecta) Wallr(flower).Results:These extracts had inhibitory effects at different concentrations (0.05,0.10,0.20 and 0.40 g/mL) against above mentioned bacteria.Escherichia coli was the most resistant strain.The highest inhibitory zone was showed by ethanolic extract of M.neglecta against Staphylococcus epidermidis(22 mm) and followed by ethanolic extract from flower of H.rosa against Staphylococcus epidermidis and Staphylococcus aureus(20 mm).The Minimum Inhibitory Concentration(MIC) and Minimum Bactericidal Concentration(MBC) values against Staphylococcus epidermidis were equal(M1C=MBC=5 mg/mL for M.neglecta extract and for H. rosa extract MIC=MBC=20 mg/mL).Conclusions:These findings suggest that these native plants have good antibacterial properties that can be used for infection control and treatment and could also be as new source for antibiotics discovery and infection treatment.
文摘Chromolaena odorata L (Asteraceae) is a bad invasive plant, found in the humid tropics and sub-tropics worldwide. It is used against dysentery, diarrhea, malaria, wound healing, headache and toothache in traditional medicine. In the present study, we investigated the antibacterial activities of different leaves extracts of Chromolaena odorata L. (cyclohexane, dichloromethane, ethyl acetate and butanol) against four clinical diarrheal strains (Klebsiella oxytoca, Salmonella enterica, Shigella sonnei and Vibrio cholera). We demonstrated that C. odorata leaves extracts show an antibacterial activity between 0.156 and 1.25 mg/mL. Bioassay-guided chromatography by bioautography with iodonitrotetrazolium-based colorimetric assay allowed the isolation and identification of two active compounds. After the combination of RP-HPLC, mass spectrometry analysis, 1D and 2D-NMR spectroscopy, we isolated and characterized two active molecules corresponding to 3’,4’,5,6,7-Pentamethoxyflavone (Sinensetin) and4’,5,6,7-Tetramethoxyflavone (Scutellareintetramethyl ether).
基金supported by a grant for supporting key research programs from Zhejiang Province (No.07-F04)a Science and Technology Fund of Zhejiang Province (No.2005C30009)
文摘Dynamic changes in mRNA expressions of liver tissue apoptosis-promoting genes Fas and Bax and apoptosis-inhibiting gene Bcl-2 of vibrio vulnificus sepsis rats were detected and the effects of antibacterial agents were examined. The rat model with Vibrio vulnificus sepsis (VV group) was established and some of the Vibrio vulnificus sepsis rats were treated with antibacterial agents (AA group). The mRNA expressions of Fas, Bax and Bcl-2 were measured by reverse transcription polymerase chain reaction (RT-PCR). As compared with normal control group (NC group), the expressions of Fas and Bax mRNA in liver tissue at all different time points in VV group were increased significantly (P<0.05), and the highest levels of Fas and Bax mRNA expressions were 6 and 12 h after the infection, respectively. At the same time, the expression of Bcl-2 mRNA in liver tissue at all different time points in VV group were decreased significantly (P<0.05), and the lowest level of Bcl-2 mRNA expression appeared 2 h after the infection. The mRNA expressions of Bcl-2 in liver tissue 9 and 12 h after the infection in AA group were increased significantly (P<0.05) compared with NC group, while the expressions of Fas and Bax mRNA were not significantly different from those of NC group. Compared with VV group, the expression of Fas mRNA in AA group was decreased (P<0.05) and Bax mRNA was decreased significantly 12 and 16 h after the infection (P<0.05), while the expressions of Bcl-2 mRNA were increased significantly 9, 12 and 16 h after the infection (P<0.05). It is concluded that the mRNA expressions of liver tissue apoptosis-promoting genes Fas and Bax were increased remarkably in vibrio vulnificus sepsis rats, whereas the expression of apoptosis-inhibiting gene Bcl-2 mRNA was decreased obviously in sepsis rats in early stage. The treatment with cefoperazone sodium and levofloxacin lactate could inhibit the expression of Fas mRNA and Bax mRNA and enhance the expression of Bcl-2 mRNA at the same time.
文摘Falsified antibacterial agents continue to pose serious public health problems around the world. They are notably responsible for resistance emergence in the treatment of infectious diseases that can lead to death. The aim of this study was to summarize the literature on the methods developed and validated to detect poor quality antibacterial agents in order to assess the impact of these available methods in the fighting against Counterfeit/substandard medicines. Thus, studies published in the time from January 2000 to July 2017, were accessible via Google Scholar and Pubmed and allowed to analyze 41 papers. The majority (30) of developed and validated methods concerned LC methods, 9 regarded UV/V is spectrophotometry and two studies simultaneously developed both methods. Antibacterial agents belonging to beta-lactams group were the most concerned by the methods developed and validated (39%), followed by quinolones (18%) and macrolides (12%). Regarding active ingredients, amoxicillin (12%) was the most concerned by the development and validation methods. In spite of several available methods to detect substandard drugs, antibacterial agents for which methods were developed and validated were the most concerned by worldwide detected non-conformities. The fight against this scourge should not be only limited by their detection, but it also requires an effective involvement of different actors notably: health authorities, international organizations, pharmaceutical industries etc.
文摘Some antibacterial agents have been shown to neutralize the biological properties of bacterial lipopolysaccharide (LPS). The aim of this study was to eluci- date the role of gentamicin, tobramycin, imipenem, tigecycline, and isoniazid in affecting the production of nitric oxide (NO) induced by LPS in mice. Groups of mice were injected intraperitoneally with LPS alone, antibacterial agent alone, or LPS in combination with an antibacterial agent. Serum NO levels were determined at 1, 3, 6 and 9 hours post-injection using the Griess reagent method. Thin layer chroma- tography was performed to determine if antibacterial agent—LPS interaction had occurred. All the antibacterial agents suppressed NO production. More- over, LPS-induced production of NO was suppressed by all the antibacterial agents, tobramycin and tigecycline being the most effective at 9 hours post-injection. Blocking of any of the stages leading to NO production by the antibacterial agents is suggested. Moreover, thin layer chromatograms obtained are suggestive of LPS-antibacterial agent interactions.
文摘A highly practical and efficient preparation of 6-methy-4H-thiochromene and 7-methyl-thiochromene[2,3-d]pyrimidine derivatives was developed via a multi-component reaction of 3-methyl-thiophenol (1), aldehydes (2), and malononitrile (3). A series of pyrimidine nucleoside, thiochromene[2,3-d]pyrimidine and thiochromene[2,3-d]pyrimidine-10-sulfone was efficiently obtained. These hybrid compounds were evaluated as potential antibacterial and anticancer agents and showed encouraging biological activities. Some of these derivatives showed broad-spectrum antitumour activity against the nine tumour subpanels tested, and demonstrated significant activity in the in vitro antitumour screening expressed by MG-MID log10GI50 value of -4.55, -4.67 and -4.73 of compounds 9a, 9b and 9c, respectively.
基金Project (06YFJMJC02700) supported by Municipal Natural Science Foundation of Tianjin, China
文摘A low temperature preparation of nano TiO2 using sol-gel method was proposed. The antibacterial properties of the treatment solution and the treated cotton fabrics obtained via a dip-padding process were evaluated. XRD pattern shows that the nano TiO2 produced is an anatase phase. Aqueous nano-dispersion of the nano TiO2 exhibites positive results as an antibacterial finishing agent for cotton fabrics. The treatment solution possesses antibacterial rates of over 92% and 88.9% against Escherichia coli and Bacillus subtilis,respectively. The treated fabrics are slightly downgraded but still maintained over 89% and 83% of reduction towards the same bacteria. After washing for 50 times,the antibacterial performances of the treated fabric still remains at a relatively high level,indicating the durable characteristic of nano TiO2 treatment.
基金Ph.D.Research Foundation of the Ministry of National Education
文摘A series of monochlorotriazine reactive antibacterial agents were synthesised by using 2,4,4’ - trichloro -2’ - hydroxydiphenyl ether as a starting material. The spectrum analyses (UV and MS) and elementary analy-ses were also carried out. These antibacterial agents can be used as the bacteria - resistance finishing agents of the cellulose fabrics. The treated fabrics possess excellent antibacterial activity and durable wash fastness. For ex-ample , the percentages of bacterial reduction of the fab-ric finished with reactive antibacterial agent 2RSDP are 98.5%, 98. 86% and 96.67% for Staphylococcus au-reus, Escherichia coli and Pseudomonas aeruginose re-spectively. After more than 100 times of washing at 60°C, the antibacterial activity still retains at a level of about 90% of the original. The relationships between the molecular structures of the reactive antibacterial finish-ing agents and their antibacterial activities are discussed.
基金the Startup Fund for Youngman Research at SJTU(No.19X100040082)the Medical and Engineering Interdisciplinary Research Fund of Shanghai Jiao Tong University(No.20X190020002).
文摘The diverse and large-scale application of disinfectants posed potential health risks and caused ecological damage during the 2019-nCoV pandemic,thereby increasing the demands for the development of disinfectants based on natural products,with low health risks and low aquatic toxicity.In the present study,a few natural naphthoquinones and their derivatives bearing the 1,4-naphthoquinone skeleton were synthesized,and their antibacterial activity against selected bacterial strains was evaluated.In vitro antibacterial activities of the compounds were investigated against Escherichia coli and Staphylococcus aureus.Under the minimum inhibitory concentration(MIC)of≤0.125μmol/L for juglone(1a),5,8-dimethoxy-1,4-naphthoquinone(1f),and 7-methyl-5-acetoxy-1,4-naphthoquinone(3),a strong antibacterial activity against S.aureus was observed.All 1,4-naphthoquinone derivatives exhibited a strong antibacterial activity,with MIC values ranging between 15.625 and 500μmol/Land ECso values rangingbetween10.56 and248.42μmol/L.Most of the synthesized compounds exhibited strong antibacterial activities against S.aureus.Among these compounds,juglone(la)showed the strongest antibacterial activity.The results from mechanistic investigations indicated that juglone,a natural naphthoquinone,caused cell death by inducing reactive oxygen species production in bacterial cells,leading to DNA damage.In addition,juglone could reduce the self-repair ability of bacterial DNA by inhibiting RecA expression.In addition to having a potent antibacterial activity,juglone exhibited low cytotoxicity in cell-based investigations.In conclusion,juglone is a strong antibacterial agent with low toxicity,indicating that its application as a bactericidal agent may be associated with low health risks and aquatic toxicity.
基金financially supported by the National Natural Science Foundation of China (Nos. 81803723, 51903062)Guangdong Basic and Applied Basic Research Foundation (No. 2019B1515120006)+2 种基金Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2019), Innovation and Entrepreneurship Team Leads the Pilot Program of Zhanjiang (No. 2020LHJH005)Discipline Construction Project of Guangdong Medical University (No. 4SG22002G)Science and Technology Projects of Guangzhou (No. 202102020757)。
文摘Cu_(2-x)S nanostructures have been intensively studied as outstanding chemodynamic therapy(CDT)and good photothermal therapy(PTT)antibacterial agents due to their highly efficient Cu(Ⅰ)-initiated Fenton-like catalytic activity and good photothermal conversion property.However,they still suffer from shortage of Cu(Ⅰ)supply in the long-term and comparatively low inherent photothermal conversion efficiency.Herein,we constructed a self-enhanced synergistic PTT/CDT nanoplatform(Cu_(1.94)S@MPN)by coating Cu_(1.94)S nanoparticles with Fe(Ⅲ)/tannic acid based metal-polyphenol networks(MPN).Activated by the acidic bacterial infection microenvironment,Cu_(1.94)S@MPN could be decomposed to continuously release Cu(Ⅱ),Fe(Ⅲ)ions and tannic acid.As the result of tannic acid-involved Cu and Fe redox cycling,Cu(Ⅰ)/Fe(Ⅱ)-rich CDT could be achieved through the highly accelerated catalytic Fenton/Fenton-like reactions.More importantly,experimental results demonstrated that Cu_(1.94)S@MPN exhibited both excellent photothermal antibacterial and photothermal-enhanced CDT properties to eradicate bacteria in vitro and in vivo.Overall,this novel nanotherapeutics has great potential to become a clinic candidate for anti-infective therapy in future.
基金supported by National Natural Science Foundation of China(31972021)R&D Projects in Key Areas of Guangdong Province(2019B020212003)+4 种基金the Science and Technology Program of Guangzhou,China(202206010177)Guangdong key research and development program(2021B0202060001)Foshan and agricultural academy cooperation projectGuangdong Modern Agriculture project(2022KJ117)Aquatic Products Center Project of GAAS。
文摘Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.
文摘Starting from sissotrin (1), a natural isoflavonoid isolated from Trifolium baccarinii (Fabaceae), one new semisynthetic derivative, 6-nitrobiochanin A (1b) and two known derivatives, 8-nitrobiochanin A (1a) and 2",3",4",6"-tetraacetylsissotrin (1c) have been obtained after performing nitration and acetylation reactions. Their structures were assigned after interpretation of their spectrometric (HR-ESI-MS) and spectroscopic (NMR 1D and 2D) data and by comparison with those reported in the literature. The substrate as well as the semisynthetic derivatives were evaluated for their antibacterial activities against six strains. The results reveal that they are inactive or weakly active on the strains tested with the exception of 8-nitrobiochanin A (1a) which showed moderate activity (MIC = 62.5 μg∙mL<sup>−1</sup>) on Staphylococcus aureus ATCC 43300.
基金supported by the National Natural Science Foundation of China(42006082)Natural Science Foundation of Jiangsu Province of China(BK20221323)+1 种基金“JBGS”Project of Seed Industry Revitalization in Jiangsu Province(JBGS[2021]034)State Key Laboratory of Developmental Biology of Freshwater Fish(2021KF009)。
文摘Long non-coding RNAs(lncRNAs)function as key modulators in mammalian immunity,particularly due to their involvement in lncRNA-mediated competitive endogenous RNA(ceRNA)crosstalk.Despite their recognized significance in mammals,research on lncRNAs in lower vertebrates remains limited.In the present study,we characterized the first immune-related lncRNA(pol-lnc78)in the teleost Japanese flounder(Paralichthys olivaceus).Results indicated that pol-lnc78 acted as a ceRNA for pol-miR-n199-3p to target the sterile alpha and armadillo motif-containing protein(SARM),the fifth discovered member of the Toll/interleukin 1(IL-1)receptor(TIR)adaptor family.This ceRNA network regulated the antibacterial responses of flounder via the Toll-like receptor(TLR)signaling pathway.Specifically,SARM acted as a negative regulator and exacerbated bacterial infection by inhibiting the expression of inflammatory cytokines IL-1βand tumor necrosis factor-α(TNF-α).Pol-miR-n199-3p reduced SARM expression by specifically interacting with the 3’untranslated region(UTR),thereby promoting SARM-dependent inflammatory cytokine expression and protecting the host against bacterial dissemination.Furthermore,pol-lnc78 sponged pol-miR-n199-3p to ameliorate the inhibition of SARM expression.During infection,the negative regulators pol-lnc78 and SARM were significantly down-regulated,while pol-miR-n199-3p was significantly up-regulated,thus favoring host antibacterial defense.These findings provide novel insights into the mechanisms underlying fish immunity and open new horizons to better understand ceRNA crosstalk in lower vertebrates.
