The problem of water and sulfur poisoning in flue gas atmosphere remains a significant obstacle for low-temperature deNO_(x) catalysts.This study investigated the sulfation mechanism of the CoMn_(2)O_(4)/CeTiO_(x)(CMC...The problem of water and sulfur poisoning in flue gas atmosphere remains a significant obstacle for low-temperature deNO_(x) catalysts.This study investigated the sulfation mechanism of the CoMn_(2)O_(4)/CeTiO_(x)(CMCT)catalyst during the selective catalytic reduction of NO_(x) with NH3 under conditions containing H2O and SO_(2) at 150℃.Employing a comprehensive suite of time-resolved analysis and characterization techniques,the evolution of sulfate species was systematically categorized into three stages:initial rapid surface sulfate accumulation,the transformation of surface sulfates to bulk metal sulfates,and partial sulfates decomposition after the removal of H2O and SO_(2).These findings indicate that bulk metal sulfates irreversibly deactivate the catalyst by distorting active component lattices and consuming oxygen vacancies,whereas surface sulfates(including ammonium sulfates and surface-coordinated metal sulfates)cause reversible performance loss through decomposition.Furthermore,the competitive adsorption of H2O and SO_(2) significantly influences the catalytic efficiency,with H2O suppressing SO_(2) adsorption while simultaneously enhancing the formation of Brönsted acid sites.This research underscores the critical role of sulfate dynamics on catalyst performance,revealing the enhanced SO_(2) resistance of the Eley-Rideal mechanism facilitated by the Ce-Ti support relative to the Langmuir-Hinshelwood pathway.Collectively,the study unravels the complex interplay of sulfate dynamics influencing catalyst performance and provides potential approaches to mitigate deactivation in demanding atmospheric conditions.展开更多
Rho kinase （ROCK） was the first downstream Rho effector found to mediate RhoA-induced actin cytoskeletal changes through effects on myosin light chain phosphorylation. There is abundant evidence that the ROCK pathwa...Rho kinase （ROCK） was the first downstream Rho effector found to mediate RhoA-induced actin cytoskeletal changes through effects on myosin light chain phosphorylation. There is abundant evidence that the ROCK pathway participates in the pathogenesis of retinal endothelial injury and proliferative epiretinal membrane traction. In this study, we investigated the effect of the ROCK pathway inhibitor Y-27632 on retinal Müller cells subjected to hypoxia or oxidative stress. Müller cells were subjected to hypoxia or oxidative stress by exposure to CoCl2 or H2O2. After a 24-hour treatment with Y-27632, the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide assay was used to assess the survival of Müller cells. Hoechst 33258 was used to detect apoptosis, while 2′,7′-dichlorodihydrofluorescein diacetate was used to measure reactive oxygen species generation. A transwell chamber system was used to examine the migration ability of Müller cells. Western blot assay was used to detect the expression levels of α-smooth muscle actin, glutamine synthetase and vimentin. After treatment with Y-27632, Müller cells subjected to hypoxia or oxidative stress exhibited a morphology similar to control cells. Y-27632 reduced apoptosis, α-smooth muscle actin expression and reactive oxygen species generation under oxidative stress, and it reduced cell migration under hypoxia. Y-27632 also upregulated glutamine synthetase expression under hypoxia but did not impact vimentin expression. These findings suggest that Y-27632 protects Müller cells against cellular injury caused by oxidative stress and hypoxia by inhibiting the ROCK pathway.展开更多
The aim of this study was to investigate the possible protective effects and mechanisms of 20-hydroxyecdysone, an insect steroid hormone, on HEO2-induced cytotoxicity in human neuroblastoma SH-SYSY cells. Pretreatment...The aim of this study was to investigate the possible protective effects and mechanisms of 20-hydroxyecdysone, an insect steroid hormone, on HEO2-induced cytotoxicity in human neuroblastoma SH-SYSY cells. Pretreatment with 20-hydroxyecdysone significantly elevated the cell viability and decreased LDH leakage in H2O2-treated SH-SY5Y cells. 20-Hydroxyecdysone also dramatically reduced malondialdehyde （MDA） contents and enhanced the superoxide dismutase （SOD） activities under oxidative stress conditions. Furthermore, 20-hydroxyecdysone pretreatment inhibited apoptosis by decreasing the Bax/Bcl-2 ratio and attenuating the activation of caspase-3. These results suggest that 20-hydroxyecdysone can protect SH-SYSY cells against H2O2-induced cytotoxicity and might potentially be used to treat neurodegenerative diseases induced by oxidative stress and anontosis.展开更多
Liver diseases with the central pathogenetic mechanism of oxidative stress are one of the main causes of mortality worldwide.Therefore,dihydroquinoline derivatives,which are precursors of hepatoprotectors and have ant...Liver diseases with the central pathogenetic mechanism of oxidative stress are one of the main causes of mortality worldwide.Therefore,dihydroquinoline derivatives,which are precursors of hepatoprotectors and have antioxidant activity,are of interest.We have previously found that some compounds in this class have the ability to normalize redox homeostasis under experimental conditions.Here,we initially analyzed the hepatoprotective potential of the dihydroquinoline derivative 1-benzoyl-6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline(BHDQ)for carbon tetrachloride(CCl4)-induced liver injury in rats.Results suggested that BHDQ normalized the alanine aminotransferase,aspartate aminotransferase,and gamma-glutamyl transpeptidase in serum.We also observed an improvement in liver tissue morphology related to BHDQ.Animals with CCl4-induced liver injuries treated with BHDQ had less oxidative stress compared to animals with CCl4-induced liver injury.BHDQ promoted activation changes in superoxide dismutase,catalase,glutathione peroxidase,glutathione reductase,and glutathione transferase on control values in animals with CCl4-induced liver injury.BHDQ also activated gene transcription in Sod1 and Gpx1 via nuclear factor erythroid 2-related factor 2 and forkhead box protein O1 factors.Therefore,the compound of concern has a hepatoprotective effect by inhibiting the development of necrotic processes in the liver tissue,through antioxidation.展开更多
Eucommia ulmoides Oliv.(EuO),also known as Duzhong,native to China,has been reported to have antioxidative function,but its cellular mechanism is not fully examined yet.We investigated inhibitory effects of EuO leaf e...Eucommia ulmoides Oliv.(EuO),also known as Duzhong,native to China,has been reported to have antioxidative function,but its cellular mechanism is not fully examined yet.We investigated inhibitory effects of EuO leaf ethanol extracts on H2O2-induced apoptosis in rat osteoblastic MC3T3-E1 cells and underlying mechanisms.Locally-grown Duzhong leaves were extracted with ethanol.MC3T3-E1 cells were treated with EuO (6.25,12.5,25,50,and 100 μg/ml) for 24 h,and then H2O2 (800 μmol/L) for an additional 24 h.Cell survival rate,percentage of apoptosis,and expressions of caspases 3,6,7,and 9 were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay,microscopic analysis,Western blotting,and reverse transcription polymerase chain reaction (RT-PCR).The final EuO leaf ethanol extract powder was detected to contain caffeotannic acid at 58 mg/g and geniposide at 3.45 mg/g by high performance liquid chromatography (HPLC).EuO remarkably restrained cell oxidative damage and increased cell survival rate in a dose-dependent manner: 0 μg/ml,0.21;6.25 μg/ml,0.28;12.5 μg/ml,0.31;25 μg/ml,0.48;50 μg/ml,0.54;and 100 μg/ml,0.66 (P<0.05),with the half-effective concentration being around 25 μg/ml.MTT results were confirmed by microscopic analysis.Western blotting and RT-PCR analyses showed that the expressions of caspases 3,6,7,and 9 were significantly decreased in the EuO-treated cells compared with the control (EuOand H2O2-free) (P<0.05),with the half-effective concentration of EuO ranging from 12.5 to 25 μg/ml.We conclude that the ethanol-extracted EuO leaf extracts promoted the growth of MC3T3-E1 cells,and suppressed the H2O2-induced apoptosis in a rat MC3T3-E1 osteogenic cell model,likely due to the inhibition of caspases’ activities.The results indicate that EuO is a potent antioxidant,which may contribute to its many cellular protective functions,including the promotion of bone growth.展开更多
The activation of adsorbed CO is an important step in CO hydrogenation. The results from TPSR of pre-adsorbed CO with H2 and syngas suggested that the presence of H2 increased the amount of CO adsorption and accelerat...The activation of adsorbed CO is an important step in CO hydrogenation. The results from TPSR of pre-adsorbed CO with H2 and syngas suggested that the presence of H2 increased the amount of CO adsorption and accelerated CO dissociation. The H2 was adsorbed first, and activated to form H＊ over metal sites, then reacted with carbonaceous species. The oxygen species for CO2 formation in the presence of hydrogen was mostly OH^＊, which reacted with adsorbed CO subsequently via CO^＊＋OH^＊ → CO2^＊＋H^＊; however, the direct CO dissociation was not excluded in CO hydrogenation. The dissociation of C-O bond in the presence of H2 proceeded by a concerted mechanism, which assisted the Boudourd reaction of adsorbed CO on the surface via CO^＊＋2H^＊ → CH^＊＋OH^＊. The formation of the surface species （CH） from adsorbed CO proceeded as indicated with the participation of surface hydrogen, was favored in the initial step of the Fischer-Tropsch synthesis.展开更多
The mitogen-activated protein kinase （MAPK） cascade is one of the a pivotal role in the regulation of stress and developmental signals in plants. major and evolutionally conserved signaling pathways and plays Here, ...The mitogen-activated protein kinase （MAPK） cascade is one of the a pivotal role in the regulation of stress and developmental signals in plants. major and evolutionally conserved signaling pathways and plays Here, we identified one gene, GhMPK6, encoding an MAPK protein in cotton. GFP fluorescence assay demonstrated that GhMAPK6 is a cytoplasm localized protein. Quantitative RT-PCR analysis revealed that mRNA accumulation of GhMPK6 was significantly promoted by abscisic acid （ABA）. Overexpression of GhMPK6 gene in the T-DNA insertion mutant atmkkl （SALK_015914） conferred a wild-type phenotype to the transgenic plants in response to ABA. Under ABA treatment, cotyledon greening/expansion in GhMPK6 transgenic lines and wild type was significantly inhibited, whereas the atmkkl mutant showed a relatively high cotyledon greening/expansion ratio. Furthermore, CAT1 expression and H2O2 levels in leaves of GhMPK6 transgenic lines and wild type were remarkably higher than those of atmkkl mutant with ABA treatment. Collectively, our results suggested that GhMPK6 may play an important role in ABA-induced CAT1 expression and H2O2 production.展开更多
This study investigated the intervention effects of Lactobacillus casei LC2W in murine(SPF C57BL/c)challenge infection models induced by Escherichia coli O157:H7.Mice were fed streptomycin with water for 3 days prior ...This study investigated the intervention effects of Lactobacillus casei LC2W in murine(SPF C57BL/c)challenge infection models induced by Escherichia coli O157:H7.Mice were fed streptomycin with water for 3 days prior to intragastric gavage by E.coli O157:H7(Control)or L.casei LC2W together with E.coli O157:H7(Intervention)to explore the role of L.casei LC2W by biochemical indicators,histological evaluation,expression of colonic pro-inflammatory and intestinal barrier factors related to enteritis.Results showed that the administration of L.casei LC2W was able to alleviate the symptoms of colitis induced by E.coli O157:H7,exhibiting lower weight loss as well as more intact colon tissue.Furthermore,L.casei LC2W could down-regulate the expression of pro-inflammatory cytokines(TNF-α,IL-6,and IL-1β)and protect the intestinal barrier function by improving the level of MUC2,ZO-1 and E-cadherin 1 compared to the control group.These results demonstrate that L.casei LC2W can reduce the severity of E.coli O157:H7 infection,and suggest L.casei LC2W may maintain the immune balance and intestinal barrier to reduce colitis.In addition,we found the effect of intervention is similar to that of prevention,which is better than that of treatment.展开更多
Primary cultures of rat cortical neurons were treated with H2O2 in an in vitro model of free radical neurotoxicity. Flavonoids extracted from the stems and leaves of Scutellaria baicalensis Georgi, known as SSF, at co...Primary cultures of rat cortical neurons were treated with H2O2 in an in vitro model of free radical neurotoxicity. Flavonoids extracted from the stems and leaves of Scutellaria baicalensis Georgi, known as SSF, at concentrations of 18.98, 37.36 and 75.92 μg/mL, protected neurons against H2O2 injury in a dose-dependent manner. SSF increased cell survival, reduced lactate dehydrogenase release and inhibited malondialdehyde production. SSF also inhibited reductions in superoxide dismutase, glutathione peroxidase and Na＋-K＋-ATPase activities. These results in-dicate that SSF can protect rat cortical neurons against H2O2-induced oxidative injury.展开更多
BACKGROUND： Extracts of ginkgo biloba leaves （EGB） and its metabolites have been reported to enhance brain function and nerve behavior. It has also been hypothesized that they can protect neurons from oxidative str...BACKGROUND： Extracts of ginkgo biloba leaves （EGB） and its metabolites have been reported to enhance brain function and nerve behavior. It has also been hypothesized that they can protect neurons from oxidative stress. OBJECTIVE： To investigate protective effects of EGB on peroxide （H2O2）-induced oxidative stress damage in PC12 cells. DESIGN： Observational contrast study. SETTING： Department ofPathophysiology, Guangdong Pharmacological College. MATERIALS： EGB was provided by Xi＇an Fujie Biotechnological Development Company; 1640 culture medium, methylthiazolyl tetrazolium （MTT）, trypsin and dimathyl sulfoxide （DMSO） by Sigma Company; PC12 cell strain by Cell Center of Medical College of Zhongshan University; calf serum by Hangzhou Sijiqing Bioengineering Company; lactate dehydrogenase （LDH） kit by Nanjing Jiancheng Bioengineering Research Institute. METHODS： The experiment was carried out in Department of Cell Biology of Guangdong Pharmacological College from June to December 2005. ①Cell culture： PC12 cells were cultured in 1640 medium containing 200 g/L fetal calf serum. The cells were diluted to 1 × 10^7 L^-1 and washed every two days. Those cells were used to experiment until they grew in logarithm on solid wall. ② Grouping and intervention： PC12 cells （1 × 10^8L^-1） were plated in 96-well plates with the density of 200 μ L/hole and divided into three groups： normal control group （routinely adding media）, H2O2 group （treating with media and H2O2 for 20 hours） and EGB group （adding media, 100μmol/L EGB and 100 μmol/L H2O2）. ③ MTT assay： PC12 cells （1 × 10^8L^-1） were plated in 96-well plates and divided into three groups with 8 holes for each group. Under sterile condition, cells were added with 5 g/L MTT （100μL） and cultured for 4 hours. And then, 200 μ L DMSO fluid was added and shaken for 30 minutes until blue crystal products formed were dissolved soundly ④ Experimental evaluation： Absorbance （A） at 630 nm was measured and LDH activity was measured at the same time. MAIN OUTCOME MEASURES： Results of MTT assay and LDH activity. RESULTS： ① Results of MTT assay： A value was lower in the H2O2 group than that in the normal control group （P 〈 0.01）, while A value was higher in the EGB group than that in the H2O2 group （P 〈 0.01）. ② LDH activity： LDH activity was higher in the H2O2 group than that in the normal control group （P 〈 0.01 ）, while LDH activity was lower in the EGB group than that in the H2O2 group （P 〈 0.01）. CONCLUSION： EGB can inhibit H2O2-induced oxidative stress damage in PC12 cells possibly by preventing damage to the cell membrane.展开更多
Objective To investigate the protective effects of Jiawei Danshen Decoction(加味丹参饮,JWDSD)on myocardial ischemia-reperfusion injury(MIRI)via the regulation of serum Hydrogen sulfide(H2S)and cardiac Beclin1,light Ch...Objective To investigate the protective effects of Jiawei Danshen Decoction(加味丹参饮,JWDSD)on myocardial ischemia-reperfusion injury(MIRI)via the regulation of serum Hydrogen sulfide(H2S)and cardiac Beclin1,light Chain 3 A/B(LC3 A/B),p62,and autophagy protein5(ATG5).Methods Seventy specific pathogen free(SPF)Sprague-Dawley(SD)rats were randomly assigned to seven groups(n=10 in each group),including normal control,sham operation,MIRI model(model),ischemic preconditioning,Na HS,JWDSD,and JWDSD+CSE inhibitor(JWDSD+PPG)groups,and orally administered the indicated drugs for 14 d.Two hours after the last administration,the left anterior decreased branch of the coronary artery of each rat in model,Na HS,JWDSD,and JWDSD+PPG groups was ligated for 30 min and subsequently reperfused for 90 min to establish the MIRI model,and the rats in the sham operation group were only exposed to the thorax after surgery without coronary ligation.Blood samples were collected to detect H2S levels using an enzyme-linked immunosorbent assay(ELISA).Heart tissues were harvested for histopathological and immunohistochemical examination and quantitative reverse transcription polymerase chain reaction analysis of Beclin1 and ATG5 m RNA expression and Western blot analysis of Beclin1,LC3 A/B,and p62 protein expression.Results(1)The serum H2S content in model group rats was significantly reduced(P<0.01),JWDSD significantly increased the serum H2S content of model group rats(P<0.01),and the CSE inhibitor(PPG)significantly reduced H2S levels in the JWDSD group rats(P<0.01).(2)Compared with the normal control group,the myocardial tissue necrosis and cell destruction occurred in the MIRI model group,and JWDSD could alleviate the myocardial tissue necrosis of model rats,but the ameliorative effect of JWDSD could be reversed by PPG.(3)Beclin1,LC3 A/B,and p62 expression levels in the heart tissues of the model group were significantly increased(P<0.001),whereas decreased by JWDSD(P<0.05,P<0.01,and P<0.001,respectively),and the inhibitory effects of JWDSD on Beclin1,LC3 A/B,and p62 expression were partially reversed by PPG(P<0.01,P<0.05,and P<0.01,respectively).(4)The expression levels of autophagy-related genes Beclin1 and ATG5 were significantly increased in the model group(P<0.001).JWDSD clearly downregulated the expression levels of Beclin1 and ATG5(P<0.05 and P<0.001,respectively),which were reversed by PPG(P<0.001).Conclusion Our experimental data show that JWDSD can exhibit an anti-MIRI role by increasing endogenous H2S generation,and downregulating the expression of Beclin1,LC3 A/B,p62 and ATG5,which are related to inhibiting autophagy signaling.展开更多
文摘The problem of water and sulfur poisoning in flue gas atmosphere remains a significant obstacle for low-temperature deNO_(x) catalysts.This study investigated the sulfation mechanism of the CoMn_(2)O_(4)/CeTiO_(x)(CMCT)catalyst during the selective catalytic reduction of NO_(x) with NH3 under conditions containing H2O and SO_(2) at 150℃.Employing a comprehensive suite of time-resolved analysis and characterization techniques,the evolution of sulfate species was systematically categorized into three stages:initial rapid surface sulfate accumulation,the transformation of surface sulfates to bulk metal sulfates,and partial sulfates decomposition after the removal of H2O and SO_(2).These findings indicate that bulk metal sulfates irreversibly deactivate the catalyst by distorting active component lattices and consuming oxygen vacancies,whereas surface sulfates(including ammonium sulfates and surface-coordinated metal sulfates)cause reversible performance loss through decomposition.Furthermore,the competitive adsorption of H2O and SO_(2) significantly influences the catalytic efficiency,with H2O suppressing SO_(2) adsorption while simultaneously enhancing the formation of Brönsted acid sites.This research underscores the critical role of sulfate dynamics on catalyst performance,revealing the enhanced SO_(2) resistance of the Eley-Rideal mechanism facilitated by the Ce-Ti support relative to the Langmuir-Hinshelwood pathway.Collectively,the study unravels the complex interplay of sulfate dynamics influencing catalyst performance and provides potential approaches to mitigate deactivation in demanding atmospheric conditions.
基金financially supported by the Scientific and Technological Project of Shaanxi Province of China,No.2016SF-010
文摘Rho kinase （ROCK） was the first downstream Rho effector found to mediate RhoA-induced actin cytoskeletal changes through effects on myosin light chain phosphorylation. There is abundant evidence that the ROCK pathway participates in the pathogenesis of retinal endothelial injury and proliferative epiretinal membrane traction. In this study, we investigated the effect of the ROCK pathway inhibitor Y-27632 on retinal Müller cells subjected to hypoxia or oxidative stress. Müller cells were subjected to hypoxia or oxidative stress by exposure to CoCl2 or H2O2. After a 24-hour treatment with Y-27632, the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide assay was used to assess the survival of Müller cells. Hoechst 33258 was used to detect apoptosis, while 2′,7′-dichlorodihydrofluorescein diacetate was used to measure reactive oxygen species generation. A transwell chamber system was used to examine the migration ability of Müller cells. Western blot assay was used to detect the expression levels of α-smooth muscle actin, glutamine synthetase and vimentin. After treatment with Y-27632, Müller cells subjected to hypoxia or oxidative stress exhibited a morphology similar to control cells. Y-27632 reduced apoptosis, α-smooth muscle actin expression and reactive oxygen species generation under oxidative stress, and it reduced cell migration under hypoxia. Y-27632 also upregulated glutamine synthetase expression under hypoxia but did not impact vimentin expression. These findings suggest that Y-27632 protects Müller cells against cellular injury caused by oxidative stress and hypoxia by inhibiting the ROCK pathway.
文摘The aim of this study was to investigate the possible protective effects and mechanisms of 20-hydroxyecdysone, an insect steroid hormone, on HEO2-induced cytotoxicity in human neuroblastoma SH-SYSY cells. Pretreatment with 20-hydroxyecdysone significantly elevated the cell viability and decreased LDH leakage in H2O2-treated SH-SY5Y cells. 20-Hydroxyecdysone also dramatically reduced malondialdehyde （MDA） contents and enhanced the superoxide dismutase （SOD） activities under oxidative stress conditions. Furthermore, 20-hydroxyecdysone pretreatment inhibited apoptosis by decreasing the Bax/Bcl-2 ratio and attenuating the activation of caspase-3. These results suggest that 20-hydroxyecdysone can protect SH-SYSY cells against H2O2-induced cytotoxicity and might potentially be used to treat neurodegenerative diseases induced by oxidative stress and anontosis.
基金supported by the Russian Foundation for Basic Research (Grant No. 20-04-00526А)
文摘Liver diseases with the central pathogenetic mechanism of oxidative stress are one of the main causes of mortality worldwide.Therefore,dihydroquinoline derivatives,which are precursors of hepatoprotectors and have antioxidant activity,are of interest.We have previously found that some compounds in this class have the ability to normalize redox homeostasis under experimental conditions.Here,we initially analyzed the hepatoprotective potential of the dihydroquinoline derivative 1-benzoyl-6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline(BHDQ)for carbon tetrachloride(CCl4)-induced liver injury in rats.Results suggested that BHDQ normalized the alanine aminotransferase,aspartate aminotransferase,and gamma-glutamyl transpeptidase in serum.We also observed an improvement in liver tissue morphology related to BHDQ.Animals with CCl4-induced liver injuries treated with BHDQ had less oxidative stress compared to animals with CCl4-induced liver injury.BHDQ promoted activation changes in superoxide dismutase,catalase,glutathione peroxidase,glutathione reductase,and glutathione transferase on control values in animals with CCl4-induced liver injury.BHDQ also activated gene transcription in Sod1 and Gpx1 via nuclear factor erythroid 2-related factor 2 and forkhead box protein O1 factors.Therefore,the compound of concern has a hepatoprotective effect by inhibiting the development of necrotic processes in the liver tissue,through antioxidation.
基金Project (No.2007C33030) supported by the Science and Technology Program of Zhejiang Province,China
文摘Eucommia ulmoides Oliv.(EuO),also known as Duzhong,native to China,has been reported to have antioxidative function,but its cellular mechanism is not fully examined yet.We investigated inhibitory effects of EuO leaf ethanol extracts on H2O2-induced apoptosis in rat osteoblastic MC3T3-E1 cells and underlying mechanisms.Locally-grown Duzhong leaves were extracted with ethanol.MC3T3-E1 cells were treated with EuO (6.25,12.5,25,50,and 100 μg/ml) for 24 h,and then H2O2 (800 μmol/L) for an additional 24 h.Cell survival rate,percentage of apoptosis,and expressions of caspases 3,6,7,and 9 were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay,microscopic analysis,Western blotting,and reverse transcription polymerase chain reaction (RT-PCR).The final EuO leaf ethanol extract powder was detected to contain caffeotannic acid at 58 mg/g and geniposide at 3.45 mg/g by high performance liquid chromatography (HPLC).EuO remarkably restrained cell oxidative damage and increased cell survival rate in a dose-dependent manner: 0 μg/ml,0.21;6.25 μg/ml,0.28;12.5 μg/ml,0.31;25 μg/ml,0.48;50 μg/ml,0.54;and 100 μg/ml,0.66 (P<0.05),with the half-effective concentration being around 25 μg/ml.MTT results were confirmed by microscopic analysis.Western blotting and RT-PCR analyses showed that the expressions of caspases 3,6,7,and 9 were significantly decreased in the EuO-treated cells compared with the control (EuOand H2O2-free) (P<0.05),with the half-effective concentration of EuO ranging from 12.5 to 25 μg/ml.We conclude that the ethanol-extracted EuO leaf extracts promoted the growth of MC3T3-E1 cells,and suppressed the H2O2-induced apoptosis in a rat MC3T3-E1 osteogenic cell model,likely due to the inhibition of caspases’ activities.The results indicate that EuO is a potent antioxidant,which may contribute to its many cellular protective functions,including the promotion of bone growth.
基金The National Key Project for Basic Research of China(973 Project)(No.2005CB221402)China National Petroleum Corporation
文摘The activation of adsorbed CO is an important step in CO hydrogenation. The results from TPSR of pre-adsorbed CO with H2 and syngas suggested that the presence of H2 increased the amount of CO adsorption and accelerated CO dissociation. The H2 was adsorbed first, and activated to form H＊ over metal sites, then reacted with carbonaceous species. The oxygen species for CO2 formation in the presence of hydrogen was mostly OH^＊, which reacted with adsorbed CO subsequently via CO^＊＋OH^＊ → CO2^＊＋H^＊; however, the direct CO dissociation was not excluded in CO hydrogenation. The dissociation of C-O bond in the presence of H2 proceeded by a concerted mechanism, which assisted the Boudourd reaction of adsorbed CO on the surface via CO^＊＋2H^＊ → CH^＊＋OH^＊. The formation of the surface species （CH） from adsorbed CO proceeded as indicated with the participation of surface hydrogen, was favored in the initial step of the Fischer-Tropsch synthesis.
基金supported by the project from Ministry of Agriculture of China for transgenic research(Nos. 2009ZX08009-117B and 2011 ZX08009-003)Ministry of Education of China(Nos.20070511001 and 200805111023)
文摘The mitogen-activated protein kinase （MAPK） cascade is one of the a pivotal role in the regulation of stress and developmental signals in plants. major and evolutionally conserved signaling pathways and plays Here, we identified one gene, GhMPK6, encoding an MAPK protein in cotton. GFP fluorescence assay demonstrated that GhMAPK6 is a cytoplasm localized protein. Quantitative RT-PCR analysis revealed that mRNA accumulation of GhMPK6 was significantly promoted by abscisic acid （ABA）. Overexpression of GhMPK6 gene in the T-DNA insertion mutant atmkkl （SALK_015914） conferred a wild-type phenotype to the transgenic plants in response to ABA. Under ABA treatment, cotyledon greening/expansion in GhMPK6 transgenic lines and wild type was significantly inhibited, whereas the atmkkl mutant showed a relatively high cotyledon greening/expansion ratio. Furthermore, CAT1 expression and H2O2 levels in leaves of GhMPK6 transgenic lines and wild type were remarkably higher than those of atmkkl mutant with ABA treatment. Collectively, our results suggested that GhMPK6 may play an important role in ABA-induced CAT1 expression and H2O2 production.
基金supported by the National Key Research and Development Program of China(No.2018YFD0501600)National Natural Science Foundation of China(No.31972056)Shanghai Agriculture Applied Technology Development Program,China(Grant No.2019-02-08-00-07-F01152).
文摘This study investigated the intervention effects of Lactobacillus casei LC2W in murine(SPF C57BL/c)challenge infection models induced by Escherichia coli O157:H7.Mice were fed streptomycin with water for 3 days prior to intragastric gavage by E.coli O157:H7(Control)or L.casei LC2W together with E.coli O157:H7(Intervention)to explore the role of L.casei LC2W by biochemical indicators,histological evaluation,expression of colonic pro-inflammatory and intestinal barrier factors related to enteritis.Results showed that the administration of L.casei LC2W was able to alleviate the symptoms of colitis induced by E.coli O157:H7,exhibiting lower weight loss as well as more intact colon tissue.Furthermore,L.casei LC2W could down-regulate the expression of pro-inflammatory cytokines(TNF-α,IL-6,and IL-1β)and protect the intestinal barrier function by improving the level of MUC2,ZO-1 and E-cadherin 1 compared to the control group.These results demonstrate that L.casei LC2W can reduce the severity of E.coli O157:H7 infection,and suggest L.casei LC2W may maintain the immune balance and intestinal barrier to reduce colitis.In addition,we found the effect of intervention is similar to that of prevention,which is better than that of treatment.
基金the State Administration of Traditional Chinese Medicine, People’s Republic of China, No.02-03-ZP18Hebei Provincial Education Department,No. 20015Hebei Provincial Hundred Outstanding Innovated Talents, First Batch
文摘Primary cultures of rat cortical neurons were treated with H2O2 in an in vitro model of free radical neurotoxicity. Flavonoids extracted from the stems and leaves of Scutellaria baicalensis Georgi, known as SSF, at concentrations of 18.98, 37.36 and 75.92 μg/mL, protected neurons against H2O2 injury in a dose-dependent manner. SSF increased cell survival, reduced lactate dehydrogenase release and inhibited malondialdehyde production. SSF also inhibited reductions in superoxide dismutase, glutathione peroxidase and Na＋-K＋-ATPase activities. These results in-dicate that SSF can protect rat cortical neurons against H2O2-induced oxidative injury.
基金Initial Funding for Doctor from Guangdong Science and Technology Bureau, No. 06300709Initial Funding for Doctor from Guangdong Pharmaceutical College, No. 43543096
文摘BACKGROUND： Extracts of ginkgo biloba leaves （EGB） and its metabolites have been reported to enhance brain function and nerve behavior. It has also been hypothesized that they can protect neurons from oxidative stress. OBJECTIVE： To investigate protective effects of EGB on peroxide （H2O2）-induced oxidative stress damage in PC12 cells. DESIGN： Observational contrast study. SETTING： Department ofPathophysiology, Guangdong Pharmacological College. MATERIALS： EGB was provided by Xi＇an Fujie Biotechnological Development Company; 1640 culture medium, methylthiazolyl tetrazolium （MTT）, trypsin and dimathyl sulfoxide （DMSO） by Sigma Company; PC12 cell strain by Cell Center of Medical College of Zhongshan University; calf serum by Hangzhou Sijiqing Bioengineering Company; lactate dehydrogenase （LDH） kit by Nanjing Jiancheng Bioengineering Research Institute. METHODS： The experiment was carried out in Department of Cell Biology of Guangdong Pharmacological College from June to December 2005. ①Cell culture： PC12 cells were cultured in 1640 medium containing 200 g/L fetal calf serum. The cells were diluted to 1 × 10^7 L^-1 and washed every two days. Those cells were used to experiment until they grew in logarithm on solid wall. ② Grouping and intervention： PC12 cells （1 × 10^8L^-1） were plated in 96-well plates with the density of 200 μ L/hole and divided into three groups： normal control group （routinely adding media）, H2O2 group （treating with media and H2O2 for 20 hours） and EGB group （adding media, 100μmol/L EGB and 100 μmol/L H2O2）. ③ MTT assay： PC12 cells （1 × 10^8L^-1） were plated in 96-well plates and divided into three groups with 8 holes for each group. Under sterile condition, cells were added with 5 g/L MTT （100μL） and cultured for 4 hours. And then, 200 μ L DMSO fluid was added and shaken for 30 minutes until blue crystal products formed were dissolved soundly ④ Experimental evaluation： Absorbance （A） at 630 nm was measured and LDH activity was measured at the same time. MAIN OUTCOME MEASURES： Results of MTT assay and LDH activity. RESULTS： ① Results of MTT assay： A value was lower in the H2O2 group than that in the normal control group （P 〈 0.01）, while A value was higher in the EGB group than that in the H2O2 group （P 〈 0.01）. ② LDH activity： LDH activity was higher in the H2O2 group than that in the normal control group （P 〈 0.01 ）, while LDH activity was lower in the EGB group than that in the H2O2 group （P 〈 0.01）. CONCLUSION： EGB can inhibit H2O2-induced oxidative stress damage in PC12 cells possibly by preventing damage to the cell membrane.
基金funding support from the National Natural Science Foundation of China(No.81704065)Hunan Provincial Natural Science Foundation(No.2019JJ40225)+1 种基金the Scientific Research Project of Education Department of Hunan Province(No.19B415,No.19C1393 and No.20C1392)Hunan Provincial Scientific Research Project of Chinese Medicine(No.2020015)。
文摘Objective To investigate the protective effects of Jiawei Danshen Decoction(加味丹参饮,JWDSD)on myocardial ischemia-reperfusion injury(MIRI)via the regulation of serum Hydrogen sulfide(H2S)and cardiac Beclin1,light Chain 3 A/B(LC3 A/B),p62,and autophagy protein5(ATG5).Methods Seventy specific pathogen free(SPF)Sprague-Dawley(SD)rats were randomly assigned to seven groups(n=10 in each group),including normal control,sham operation,MIRI model(model),ischemic preconditioning,Na HS,JWDSD,and JWDSD+CSE inhibitor(JWDSD+PPG)groups,and orally administered the indicated drugs for 14 d.Two hours after the last administration,the left anterior decreased branch of the coronary artery of each rat in model,Na HS,JWDSD,and JWDSD+PPG groups was ligated for 30 min and subsequently reperfused for 90 min to establish the MIRI model,and the rats in the sham operation group were only exposed to the thorax after surgery without coronary ligation.Blood samples were collected to detect H2S levels using an enzyme-linked immunosorbent assay(ELISA).Heart tissues were harvested for histopathological and immunohistochemical examination and quantitative reverse transcription polymerase chain reaction analysis of Beclin1 and ATG5 m RNA expression and Western blot analysis of Beclin1,LC3 A/B,and p62 protein expression.Results(1)The serum H2S content in model group rats was significantly reduced(P<0.01),JWDSD significantly increased the serum H2S content of model group rats(P<0.01),and the CSE inhibitor(PPG)significantly reduced H2S levels in the JWDSD group rats(P<0.01).(2)Compared with the normal control group,the myocardial tissue necrosis and cell destruction occurred in the MIRI model group,and JWDSD could alleviate the myocardial tissue necrosis of model rats,but the ameliorative effect of JWDSD could be reversed by PPG.(3)Beclin1,LC3 A/B,and p62 expression levels in the heart tissues of the model group were significantly increased(P<0.001),whereas decreased by JWDSD(P<0.05,P<0.01,and P<0.001,respectively),and the inhibitory effects of JWDSD on Beclin1,LC3 A/B,and p62 expression were partially reversed by PPG(P<0.01,P<0.05,and P<0.01,respectively).(4)The expression levels of autophagy-related genes Beclin1 and ATG5 were significantly increased in the model group(P<0.001).JWDSD clearly downregulated the expression levels of Beclin1 and ATG5(P<0.05 and P<0.001,respectively),which were reversed by PPG(P<0.001).Conclusion Our experimental data show that JWDSD can exhibit an anti-MIRI role by increasing endogenous H2S generation,and downregulating the expression of Beclin1,LC3 A/B,p62 and ATG5,which are related to inhibiting autophagy signaling.
