AIM:To investigate free-radical scavenger effect of n- acetylcysteine in rats intragastrically fed with ethanol. METHODS:Twenty-four rats divided into three groups were fed with ethanol (6 g/kg/day,Group 1),ethanol an...AIM:To investigate free-radical scavenger effect of n- acetylcysteine in rats intragastrically fed with ethanol. METHODS:Twenty-four rats divided into three groups were fed with ethanol (6 g/kg/day,Group 1),ethanol and n- acetylcysteine (1 g/kg,Group 2),or isocaloric dextrose (control group,Group 3) for 4 weeks.Then animals were sacrificed under ether anesthesia,and intracardiac blood and liver tissues were obtained.Measurements were made in both serum and homogenized liver tissues. Malondialdehyde (MDA) level was measured by TBARS method.Glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) levels were studied by commercial kits. Kruskal-Wallis test was used for statistical analysis. RESULTS:ALT and AST in Group 1 (154 U/L and 302 U/L, respectively) were higher than those in Group 2 (94 U/L and 155 U/L) and Group 3 (99 U/L and 168 U/L) (P=0.001 for both).Serum and tissue levels of MDA in Group 1 (1.84 nmol/mL and 96 nmol/100 mg-protein) were higher than that in Group 2 (0.91 nmol/mL and 64 nmol/100 mg protein) and Group 3 (0.94 nmol/ml and 49 nmol/100 mg-protein) (P<0.001 for both).On the other hand,serum GSH-Px level in Group 1 (8.21 U/g Hb) was lower than that in Group 2 (16 U/g Hb) and Group 3 (16 U/g-Hb) (P<0.001).Serum and liver tissue levels of SOD in Group 1 (11 U/mL and 26 U/100 rag-protein) were lower than that in Group 2 (18 U/ mL and 60 U/100 mg protein) and Group 3 (20 U/mL and 60 U/100 rag-protein) (P<0.001 for both). CONCLUSION:Ethanol-induced liver damage was associated with oxidative stress,and co-administration of n-acetylolsteine attenuates this damage effectively in rat model.展开更多
The antioxidative capacity of astaxanthin and enzyme activity of reactive oxygen eliminating enzymes such as superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX) were studied in th...The antioxidative capacity of astaxanthin and enzyme activity of reactive oxygen eliminating enzymes such as superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX) were studied in three cell types of Haematococcus pluvialis exposed to high concentrations of a superoxide anion radical (O2ˉ).The results show that defensive enzymes and astaxanthin-related mechanisms were both active in H.pluvialis during exposure to reactive oxygen species (ROS) such as Oˉ2.Astaxanthin reacted with ROS much faster than did the protective enzymes,and had the strongest antioxidative capacity to protect against lipid peroxidation.The defensive mechanisms varied significantly between the three cell types and were related to the level of astaxanthin that had accumulated in those cells.Astaxanthin-enriched red cells had the strongest antioxidative capacity,followed by brown cells,and astaxanthin-deficient green cells.Although there was no significant increase in expression of protective enzymes,the malondialdehyde (MDA) content in red cells was sustained at a low level because of the antioxidative effect of astaxanthin,which quenched Oˉ2 before the protective enzymes could act.In green cells,astaxanthin is very low or absent;therefore,scavenging of ROS is inevitably reliant on antioxidative enzymes.Accordingly,in green cells,these enzymes play the leading role in scavenging ROS,and the expression of these enzymes is rapidly increased to reduce excessive ROS.However,because ROS were constantly increased in this study,the enhance enzyme activity in the green cells was not able to repair the ROS damage,leading to elevated MDA content.Of the four defensive enzymes measured in astaxanthin-deficient green cells,SOD eliminates Oˉ2,POD eliminates H2O2,which is a by-product of SOD activity,and APX and CAT are then initiated to scavenge excessive ROS.展开更多
Isothiocyanates(ITCs) extracts were prepared from fresh broccoli.Their antioxidant properties were evaluated by using the in vitro bioassays,including superoxide anion radical( 2 O·-) ,hydroxyl radical(HO·-)...Isothiocyanates(ITCs) extracts were prepared from fresh broccoli.Their antioxidant properties were evaluated by using the in vitro bioassays,including superoxide anion radical( 2 O·-) ,hydroxyl radical(HO·-) and 2,2-diphenyl-1-picrylhydracyl(DPPH·) radical-scavenging methods,lipid peroxidation assay,and reducing power assay.The ITCs extracts exhibited significant dose-dependent antioxidant activities(P<0.01) .Its antioxidant-stability was affected by temperature and storage condition,although it was more stable than vitamin C(Vc) .GC-MS iden-tified sulforaphane in the ITCs extracts.The antioxidant activity of sulforaphane was approximately one tenth to one fifth of that of Vc.Sulforaphane was experimented to be one of dominating contributors to antioxidant capacity of ITCs extracts.However,there was no direct antioxidant activity found for benzyl isothiocyanate(BITC) in vitro. Therefore,it could be concluded that the general group(-N=C=S) was not the essential part for the antioxidant activity of sulforaphane.It is suggested that the ITCs extracts from broccoli can be developed into a promising food additive for healthy food.展开更多
Sea cucumber is a traditional nutritional food and medicinal resource with many bioactive components in China. Holothuriafuscogliva is a big sea cucumber with a rich of bioactive polysaccharides. To investigate the bi...Sea cucumber is a traditional nutritional food and medicinal resource with many bioactive components in China. Holothuriafuscogliva is a big sea cucumber with a rich of bioactive polysaccharides. To investigate the bioactivities of the polysaccharides from sea cucumber H. fuscogliva, we prepared the sulfated polysaccharides （HfP） from sea cucumber H. fuscogliva using a protease hydrolysis method. Antioxidant activities of HfP were investigated, including hydroxyl radical scavenging activity and superoxide radical scavenging activity. And, the anticoagulant activities of HfP were studied, including the activated partial thromboplastin time （APTT）, prothrombin time （PT） and thrombin time （TT）. The average molecular weight was 1 867.1 Da, with a sulfate content of 20.7%. In addition, the molar ratio of monosaccharide composition of HfP was Man： Rha： Glc A： Glc： Gal： Xyl： Fuc=0.083 6： 0.437： 0.134： 0： 1.182： 0.748： 1. It had a strong antioxidant activity, the hydroxyl and superoxide radical scavenging activity ECs0 of HfP was 3.74 and 0.037 mg/mL, respectively. It also showed a good anticoagulant activity in our study. The APTT of HfP was much higher than that of heparin sodium, and the PT and TT of HfP was close to that ofheparin sodium at a low concentration. Therefore, HfP shows a good antioxidant and anticoagulant activity and it may become a potential candidate of the natural antioxidant and anticoagulant and will have a good application future in health product or medicine industry.展开更多
Fish skin collagen hydrolysates （FSCH） were prepared from walleye pollock （Theragra chalcogramrna） using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3...Fish skin collagen hydrolysates （FSCH） were prepared from walleye pollock （Theragra chalcogramrna） using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of 〈1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical （DPPH）, superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione （GSH）. FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore FSCH may have potential applications in the medicine and food industries.展开更多
Apostichopus japonicus Selenka is an ideal tonic food that is used traditionally in many Asian countries, and it contains many bioactive substances, such as antioxidant, antimicrobial, and anticancer materials. To con...Apostichopus japonicus Selenka is an ideal tonic food that is used traditionally in many Asian countries, and it contains many bioactive substances, such as antioxidant, antimicrobial, and anticancer materials. To convert waste liquid generated during production into a useful resource, extract from waste liquid was isolated by column chromatography and studied by the pyrogallol autoxidation and 1,10-phenanthroline-Fe^2＋ oxidation methods. Results show that the extract scavenged about 91% of the superoxide anion radical at a concentration of 1.4 mg/mL and 24% of the hydroxyl radical at 3.3 mg/mL. Four compounds were isolated and identified from the extract： 2,4-dihydroxy-5-methyl-1,3-azine; 2,4-dihydroxy- 1,3-diazine; 3-O-β-D-quinovopranosyl-（1→2）-4-O-sodium sulfate-β-D-xylopranosyl]-holosta-9（11）-ene313,12β,17α-triol; and 24-ethyl-5α-cholesta-7-ene-3β-O-β-D-xylopyranoside. All of these compounds are known in A. japonicus, and were found in the waste liquid for the first time.展开更多
Based on the layer-by-layer self-assembly of positively charged cetyltrimethylammonium bromide （CTAB） wrapped gold na- norods （AuNRs） and negatively charged superoxide dismutase （SOD） from their aqueous solution...Based on the layer-by-layer self-assembly of positively charged cetyltrimethylammonium bromide （CTAB） wrapped gold na- norods （AuNRs） and negatively charged superoxide dismutase （SOD） from their aqueous solutions on cysteine modified gold electrode （Cys/Au）, a third generation electrochemical biosensor （（SOD/AuNRs）2/Cys/Au） for superoxide anion （02＂-） was developed. The two layers assembly of SOD/AuNRs can significantly enhance the direct electron transfer between SOD and the electrode. The functional enzymatic activities of the SOD offer an electrochemical approach to the determination of 02＂-. In the reductive regions, the proposed sensor exhibits excellent analytical performances, such as wide linear range （200 nM to 0.2 mM O2-）, low detection limit （100 nM O2-）, high sensitivity （22.11 nA cm-2 μM-1）, short response time （less than 5 s）, good stability and reproducibility, while no obvious interferences are caused by commonly met interfering species including hydrogen peroxide （H202）, uric acid （UA） and ascorbic acid （AA）.展开更多
基金the research Fund of the University of Istanbul,Project Number:T-589/240698
文摘AIM:To investigate free-radical scavenger effect of n- acetylcysteine in rats intragastrically fed with ethanol. METHODS:Twenty-four rats divided into three groups were fed with ethanol (6 g/kg/day,Group 1),ethanol and n- acetylcysteine (1 g/kg,Group 2),or isocaloric dextrose (control group,Group 3) for 4 weeks.Then animals were sacrificed under ether anesthesia,and intracardiac blood and liver tissues were obtained.Measurements were made in both serum and homogenized liver tissues. Malondialdehyde (MDA) level was measured by TBARS method.Glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) levels were studied by commercial kits. Kruskal-Wallis test was used for statistical analysis. RESULTS:ALT and AST in Group 1 (154 U/L and 302 U/L, respectively) were higher than those in Group 2 (94 U/L and 155 U/L) and Group 3 (99 U/L and 168 U/L) (P=0.001 for both).Serum and tissue levels of MDA in Group 1 (1.84 nmol/mL and 96 nmol/100 mg-protein) were higher than that in Group 2 (0.91 nmol/mL and 64 nmol/100 mg protein) and Group 3 (0.94 nmol/ml and 49 nmol/100 mg-protein) (P<0.001 for both).On the other hand,serum GSH-Px level in Group 1 (8.21 U/g Hb) was lower than that in Group 2 (16 U/g Hb) and Group 3 (16 U/g-Hb) (P<0.001).Serum and liver tissue levels of SOD in Group 1 (11 U/mL and 26 U/100 rag-protein) were lower than that in Group 2 (18 U/ mL and 60 U/100 mg protein) and Group 3 (20 U/mL and 60 U/100 rag-protein) (P<0.001 for both). CONCLUSION:Ethanol-induced liver damage was associated with oxidative stress,and co-administration of n-acetylolsteine attenuates this damage effectively in rat model.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (No. 2008AA09Z403)the Special Project for Marine Public Welfare Industry (No.200705010)the National Natural Science Foundation of China (No. 30771638)
文摘The antioxidative capacity of astaxanthin and enzyme activity of reactive oxygen eliminating enzymes such as superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX) were studied in three cell types of Haematococcus pluvialis exposed to high concentrations of a superoxide anion radical (O2ˉ).The results show that defensive enzymes and astaxanthin-related mechanisms were both active in H.pluvialis during exposure to reactive oxygen species (ROS) such as Oˉ2.Astaxanthin reacted with ROS much faster than did the protective enzymes,and had the strongest antioxidative capacity to protect against lipid peroxidation.The defensive mechanisms varied significantly between the three cell types and were related to the level of astaxanthin that had accumulated in those cells.Astaxanthin-enriched red cells had the strongest antioxidative capacity,followed by brown cells,and astaxanthin-deficient green cells.Although there was no significant increase in expression of protective enzymes,the malondialdehyde (MDA) content in red cells was sustained at a low level because of the antioxidative effect of astaxanthin,which quenched Oˉ2 before the protective enzymes could act.In green cells,astaxanthin is very low or absent;therefore,scavenging of ROS is inevitably reliant on antioxidative enzymes.Accordingly,in green cells,these enzymes play the leading role in scavenging ROS,and the expression of these enzymes is rapidly increased to reduce excessive ROS.However,because ROS were constantly increased in this study,the enhance enzyme activity in the green cells was not able to repair the ROS damage,leading to elevated MDA content.Of the four defensive enzymes measured in astaxanthin-deficient green cells,SOD eliminates Oˉ2,POD eliminates H2O2,which is a by-product of SOD activity,and APX and CAT are then initiated to scavenge excessive ROS.
基金Supported by the Natural Science Foundation of Zhejiang Province(Y3090135)
文摘Isothiocyanates(ITCs) extracts were prepared from fresh broccoli.Their antioxidant properties were evaluated by using the in vitro bioassays,including superoxide anion radical( 2 O·-) ,hydroxyl radical(HO·-) and 2,2-diphenyl-1-picrylhydracyl(DPPH·) radical-scavenging methods,lipid peroxidation assay,and reducing power assay.The ITCs extracts exhibited significant dose-dependent antioxidant activities(P<0.01) .Its antioxidant-stability was affected by temperature and storage condition,although it was more stable than vitamin C(Vc) .GC-MS iden-tified sulforaphane in the ITCs extracts.The antioxidant activity of sulforaphane was approximately one tenth to one fifth of that of Vc.Sulforaphane was experimented to be one of dominating contributors to antioxidant capacity of ITCs extracts.However,there was no direct antioxidant activity found for benzyl isothiocyanate(BITC) in vitro. Therefore,it could be concluded that the general group(-N=C=S) was not the essential part for the antioxidant activity of sulforaphane.It is suggested that the ITCs extracts from broccoli can be developed into a promising food additive for healthy food.
基金Supported by the Science and Technology Service Network Program of Chinese Academy of Sciences(No.KFJ-EW-STS-060)the National Special Research Fund for Non-Profit Marine Sector(No.201405038-2)+1 种基金the Scientific and Technological Innovation ProjectFinancially Supported by Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)
文摘Sea cucumber is a traditional nutritional food and medicinal resource with many bioactive components in China. Holothuriafuscogliva is a big sea cucumber with a rich of bioactive polysaccharides. To investigate the bioactivities of the polysaccharides from sea cucumber H. fuscogliva, we prepared the sulfated polysaccharides （HfP） from sea cucumber H. fuscogliva using a protease hydrolysis method. Antioxidant activities of HfP were investigated, including hydroxyl radical scavenging activity and superoxide radical scavenging activity. And, the anticoagulant activities of HfP were studied, including the activated partial thromboplastin time （APTT）, prothrombin time （PT） and thrombin time （TT）. The average molecular weight was 1 867.1 Da, with a sulfate content of 20.7%. In addition, the molar ratio of monosaccharide composition of HfP was Man： Rha： Glc A： Glc： Gal： Xyl： Fuc=0.083 6： 0.437： 0.134： 0： 1.182： 0.748： 1. It had a strong antioxidant activity, the hydroxyl and superoxide radical scavenging activity ECs0 of HfP was 3.74 and 0.037 mg/mL, respectively. It also showed a good anticoagulant activity in our study. The APTT of HfP was much higher than that of heparin sodium, and the PT and TT of HfP was close to that ofheparin sodium at a low concentration. Therefore, HfP shows a good antioxidant and anticoagulant activity and it may become a potential candidate of the natural antioxidant and anticoagulant and will have a good application future in health product or medicine industry.
基金supported by the High Technology Research and Development Program of China (No. 2006AA09Z438)the National Natural Science Foundation of China (No. 30871943).
文摘Fish skin collagen hydrolysates （FSCH） were prepared from walleye pollock （Theragra chalcogramrna） using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of 〈1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical （DPPH）, superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione （GSH）. FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore FSCH may have potential applications in the medicine and food industries.
基金Supported by the National Special Research Fund for Non-Profit Sector(Ocean)(No.201205025-5)
文摘Apostichopus japonicus Selenka is an ideal tonic food that is used traditionally in many Asian countries, and it contains many bioactive substances, such as antioxidant, antimicrobial, and anticancer materials. To convert waste liquid generated during production into a useful resource, extract from waste liquid was isolated by column chromatography and studied by the pyrogallol autoxidation and 1,10-phenanthroline-Fe^2＋ oxidation methods. Results show that the extract scavenged about 91% of the superoxide anion radical at a concentration of 1.4 mg/mL and 24% of the hydroxyl radical at 3.3 mg/mL. Four compounds were isolated and identified from the extract： 2,4-dihydroxy-5-methyl-1,3-azine; 2,4-dihydroxy- 1,3-diazine; 3-O-β-D-quinovopranosyl-（1→2）-4-O-sodium sulfate-β-D-xylopranosyl]-holosta-9（11）-ene313,12β,17α-triol; and 24-ethyl-5α-cholesta-7-ene-3β-O-β-D-xylopyranoside. All of these compounds are known in A. japonicus, and were found in the waste liquid for the first time.
基金supported by the National Natural Science Foundation of China (20805013, 20905024&21075031)the National Basic Research Program of China (2009CB421601 & 2011CB911002)the Natural Science Foundation of Hunan Province (09JJ4006 & 09JJ4007)
文摘Based on the layer-by-layer self-assembly of positively charged cetyltrimethylammonium bromide （CTAB） wrapped gold na- norods （AuNRs） and negatively charged superoxide dismutase （SOD） from their aqueous solutions on cysteine modified gold electrode （Cys/Au）, a third generation electrochemical biosensor （（SOD/AuNRs）2/Cys/Au） for superoxide anion （02＂-） was developed. The two layers assembly of SOD/AuNRs can significantly enhance the direct electron transfer between SOD and the electrode. The functional enzymatic activities of the SOD offer an electrochemical approach to the determination of 02＂-. In the reductive regions, the proposed sensor exhibits excellent analytical performances, such as wide linear range （200 nM to 0.2 mM O2-）, low detection limit （100 nM O2-）, high sensitivity （22.11 nA cm-2 μM-1）, short response time （less than 5 s）, good stability and reproducibility, while no obvious interferences are caused by commonly met interfering species including hydrogen peroxide （H202）, uric acid （UA） and ascorbic acid （AA）.
