In search for new potential inhibitors some new fluorine substituted thiobarbituric acid derivatives (2-4, 7, 8) and their fused/isolated heterobicyclic nitrogen systems (5, 6, 9, 10, 11, 12) have been synthesized fro...In search for new potential inhibitors some new fluorine substituted thiobarbituric acid derivatives (2-4, 7, 8) and their fused/isolated heterobicyclic nitrogen systems (5, 6, 9, 10, 11, 12) have been synthesized from heterocyclization of fluorinated 1,3-diketoamine (1) with CS2 followed by ring closure reactions with primary nitrogen reagents. Structures of the targets have been established from elemental analysis and spectral data. Some synthesized systems have been evaluated as anti-HIV-1 and of cyclin-dependent kinase 2 (CDK2) for cell tumor division.展开更多
Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo g...Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metaI ions, in most of the studied chelates, and that the two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 were coordinated either in the enol or the keto form. IR spetra also showed that Fe(III)-, Ni(II)-, Mn(II)-, VO(II)-L1 and Cu(II)-L2 chelates behaved in a bidentate manner, in contrast with the two (1:1) M:L cobalt chelates with the two ligands are tridentate.TG analysis indicated the presence of three to twelve water molecules of hydration eliminated on heating up to 150℃ and one or two coordinated water molecules removed at 150~180℃.The octahedral structure is proposed fOr all the chelates, except Cu(II)-L2 and Ni(II)-L1 chelates which have square planar geometry, based on their electronic spectra展开更多
A series of 5-arylidene thiobarbituric acids were prepared from aromatic aldehydes and thiobarbituric acid in water without catalyst conditions in good yields. The structures were characterized by elemental analysis,...A series of 5-arylidene thiobarbituric acids were prepared from aromatic aldehydes and thiobarbituric acid in water without catalyst conditions in good yields. The structures were characterized by elemental analysis, IR and 1H NMR spectra.展开更多
AIM: Oxygen free radical mediated tissue damage is well established in pathogenesis of acute pancreatitis (AP).Whether nitric oxide (NO) plays a deleterious or a protective role is unknown. In alcohol-induced AP, we s...AIM: Oxygen free radical mediated tissue damage is well established in pathogenesis of acute pancreatitis (AP).Whether nitric oxide (NO) plays a deleterious or a protective role is unknown. In alcohol-induced AP, we studied NO, lipooxidative damage and glutathione in pancreas, lung and circulation.METHODS: AP was induced in rats (n = 25) by injection of ethyl alcohol into the common biliary duct. A sham laparatomy was performed in controls (n = 15). After 24 h the animals were killed, blood and tissue sampling were done.RESULTS: Histopathologic evidence confirmed the development of AP. Marked changes were observed in the pulmonary tissue. Compared with controls, the AP group displayed higher values for NO metabolites in pancreas and lungs, and thiobarbituric acid reactive substances in circulation. Glutathione was lower in pancreas and in circulation. Glutathione and NO were positively correlated in pancreas and lungs of controls but negatively correlated in circulation of experimental group. In the experimental group, plasma thiobarbituric acid reactive substances were negatively correlated with pancreas thiobarbituric acid reactive substances but positively correlated with pancreas NO.CONCLUSION: NO increases in both pancreas and lungs in AP and NO contributes to the pathogenesis of AP under oxidative stress.展开更多
AIM: To examine the protective effect of estradiol on the cultured hepatocytes under oxidative stress. METHODS: Hepatocytes of rat were isolated by using perfusion method, and oxidative stress was induced by a serum-f...AIM: To examine the protective effect of estradiol on the cultured hepatocytes under oxidative stress. METHODS: Hepatocytes of rat were isolated by using perfusion method, and oxidative stress was induced by a serum-free medium and FeNTA. MDA level was determined with TBA method. Cell damage was assessed by LDH assay. Apoptosis of hepatocytes was assessed with cytoflowmetric analysis. Expression of Bcl-xl in cultured hepatocytes was detected by Western blot. The radical-scavenging activity of estradiol was valued by its ability to scavenge the stable free radical of DDPH. RESULTS: Oxidative stress increased LDH from 168 +/- 25 x 10(-6)IU.cell(-1) to 780 +/- 62 x 10(-6)IU.cell(-1) and MDA(from 0.28 +/- 0.07 x 10(-6)nmol.cell(-1) to 1.35 +/- 0.12 x 10(-6)nmol.cell(-1)) levels in cultured hepatocyte, and estradiol inhibited both LDH and MDA production in a dose dependent manner. In the presence of estradiol 10(-6)mol.L(-1), 10( -7 )mol.L(-1) and 10(-8)mol.L(-1),the LDH levels are 410 +/- 53 x 10(-6)IU.cell(-1) (P【0.01 vs oxidative group), 530 +/- 37 X 10(-6)IU.cell(-1 ) (P【0.01 vs oxidative group), 687+/-42 x 10(-6)IU.cell(-1) (P【0.05 vs oxidative group) respectively, and the MDA level are 0.71+/-0.12 x 10(-6)nmol.cell(-1) (P【0.01 vs oxidative group),0.97+/-0.11 x 10(-6)nmol.cell(-1 )(P【0.01 vs oxidative group) and 1.27+/-0.19 x 10(-6)nmol.cell(-1) respectively. Estradiol suppressed apoptosis of hepatocytes induced by oxidative stress, administration of estradiol(10(-6)mol/L)decreased the apoptotic rate of hepatocytes under oxidative stress from 18.6 +/- 1.2% to 6.5 +/-2.5%, P【0.01. Bcl-xl expression was related to the degree of liver cell damage due to oxidative stress, and estradiol showed a protective action. CONCLUSION: Estradiol protects hepatocytes from oxidative damage by means of its antioxidant activity.展开更多
AIM: There is increasing evidence that alcohol-induced liverdamage may be associated with increased oxidative stress.We aimed to investigate free-radical scavenger effect of n-acetylcysteine in rats intragastrically f...AIM: There is increasing evidence that alcohol-induced liverdamage may be associated with increased oxidative stress.We aimed to investigate free-radical scavenger effect of n-acetylcysteine in rats intragastrically fed with ethanol.METHODS: Twenty-four rats divided into three groups werefed 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 weresacrificed under ether anesthesia, intracardiac blood andliver tissues were obtained. Measurements were performedboth in serum and in homogenized liver tissues.Malondialdehyde (MDA) level was measured by TBARSmethod. Glutathione peroxidase (GSH-Px) and superoxidedismutase (SOD) levels were studied by commercial kits.Kruskal-Wallis test was used for statistical analysis.RESULTS: ALT and AST in Group 1 (154 U/Land 302 U/L,respectively) were higher than those in Group 2 (94 U/L and155 U/L) and Group 3 (99 U/L and 168 U/L) (P＝0.001 forboth). Serum and tissue levels of MDA in Group 1 (1.84 nmol/mL and 96 nmol/100 mg-protein) were higher than 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 forboth). On the other hand, serum GSH-Px level in Group 1(8.21 U/g-Hb) was lower than Group 2 (16 U/g-Hb) andGroup 3 (16 U/g-Hb) (P＜0.001). Serum and liver tissue levelsof SOD in Group 1 (11 U/mL and 26 U/100 mg-protein)were lower than Group 2 (18 U/mL and 60 U/100 mg-protein)and Group 3 (20 U/mL and 60 U/100 mg-protein) (P＜0.001for both).CONCLUSION: This study demonstrated that ethanol-induced liver damage is associated with oxidative stress,and co-administration of n-acetylcysteine attenuates thisdamage effectively in rat model.展开更多
AIM: To assess the levels of antioxidant capacity and oxidative damage in blood of chronic pancreatitis (CP) patients in comparison with those in healthy control sub- jects, by using several different analytical techn...AIM: To assess the levels of antioxidant capacity and oxidative damage in blood of chronic pancreatitis (CP) patients in comparison with those in healthy control sub- jects, by using several different analytical techniques. METHODS: Thirty-five CP patients and 35 healthy con- trol subjects were investigated prospectively with re- spect to plasma levels of thiols, ferric reducing ability of plasma (FRAP, i.e. antioxidant capacity), levels of protein carbonyls and thiobarbituric acid reactive substances (TBARS). Additionally, we evaluated the production of reactive oxygen species (ROS) in whole blood. RESULTS: The antioxidative thiols including cysteine, cysteinylglycine and glutathione were significantly lower in CP patients. In addition, the non-enzymatic antioxi- dant capacity was significantly lower in CP patients, which correlated with the amount of oxidative protein (protein carbonyls) and the extent of lipid damage (TBARS), both were significantly higher in CP patients. The ROS production in whole blood after stimulation with phorbol 12-myritate 13-acetaat, demonstrated a strong tendency to produce more ROS in CP patients. CONCLUSION: Oxidative stress may contribute to the pathogenesis of chronic pancreatitis by decreasing anti- oxidant capacity and increasing oxidative damage in CP patients may be a rationale for intervention with antioxi- dant therapy.展开更多
Sodium erythorbate, antioxidant and curing accelerator, used in meat products, have no vitamin functionality. Ascorbic acid （AA）, in contrast, is a powerful antioxidant, but very unstable. The application of encapsu...Sodium erythorbate, antioxidant and curing accelerator, used in meat products, have no vitamin functionality. Ascorbic acid （AA）, in contrast, is a powerful antioxidant, but very unstable. The application of encapsulated AA in frankfurters could allow the incorporation of an antioxidant with vitamin functionality and improved stability. The aim of this study was to evaluate the application ofAA microcapsules in frankfurters and the effects of their application on the product. Different analyses were conducted. The values obtained for mass loss, moisture content, water activity, pH and instrumental color were not significantly different among the treatments. The frankfurters containing the microcapsutes exhibited the lowest hardness value （approximately 5,000 g）, resulting in better scores in the sensory analysis. It was possible to apply the AA microcapsules without compromising the oxidative stability and physicochemical characteristics of the product, providing a promising method for protecting AA and producing fortified frankfurters.展开更多
The freshwater fish Carassius auratus was chosen as an experimental subject, and their hepatic biochemical responses to the medium-term exposure of Benzo（k）fluoranthene （BkF） alone and in combination with PCB 118 ...The freshwater fish Carassius auratus was chosen as an experimental subject, and their hepatic biochemical responses to the medium-term exposure of Benzo（k）fluoranthene （BkF） alone and in combination with PCB 118 and dichlorodiphenyltrichloroethane （DDT） were investigated by measuring the reduced glutathione （GSH）, glutathione S-transferase （GST）, and thiobarbituric acid reactive substances （TBARS）, to assess sublethal effects. The hepatic GSH content was significantly inhibited by organic pollutants, alone and in mixtures, while the TBARS content was significantly induced after three days of exposure. Bell-shaped concentration-response charts of GST activities were obtained. Significant dose-response relationships were found for hepatic GSH and TBARS contents of all concentrations and for the GST activity, except at the highest concentration. The GSH content, GST activity, and TBARS content in Carassius auratus were confirmed as useful biomarkers of exposure to organic pollutions.展开更多
Bis-thiobarbiturate derivatives 1-15 have been synthesized, characterized by 1HNMR and El-MS and screened for urease inhibition. All compounds showed various degree of urease inhibitory activity with iC50 values rangi...Bis-thiobarbiturate derivatives 1-15 have been synthesized, characterized by 1HNMR and El-MS and screened for urease inhibition. All compounds showed various degree of urease inhibitory activity with iC50 values ranging 7.45 ± 0.12 - 74.24 ± 0.81 μmol/L while the standard thiourea behaved normally （ICso = 21.10 ±0.12）. Compounds I （IC50= 7.45 ± 0.12 ]μmol/L）, 9 （IC50 =18,17 ± 1.03 bmol/L） and 13 （IC50= 8.61 ± 0.45 bmol/L） showed excellent urease inhibitory activity in the series. Molecular modeling studies were performed to understand the binding site with the bimetallic nickel center of the enzyme. Structure-activity relationship has also been established for these compounds. This study identified bis- thiobarbiturate as a novel class of urease inhibitors.展开更多
The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species （TBARS） assay, total phenol...The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species （TBARS） assay, total phenol content, evaluation of reactive oxygen species （ROS） in liver mitochondria, Fe2＋ chelating and 2,2-diphenyl-lpicrylhydrazyl （DPPH） scavenging activities. Both extracts had high antioxidant properties and could inhibit FeE＋ and sodium nitroprusside lipid peroxidation in the liver. Total phenol content of ethyl acetate fraction and aqueous extract were 4.50 ±2.26 and 1.21±3.12 mg/g, respectively. Both extracts had a maximal effect at the lowest concentrations tested （15 μg/mL for ethyl acetate and 150 μg/mL for the aqueous）. Ethyl acetate fraction showed that the highest values of antioxidant activity is probably associated with its high phenolic content, Fe2＋ chelating and DPPH scavenging activities. It is therefore concluded that ethyl acetate fraction and to a less extent the aqueous fractions are potent inhibitor of lipid peroxidation.展开更多
Objective:To investigate the effect of oxidized transitional metal（ferric and cupric） ions on the amino acids.Methods:25 mmol/L hydroxyproline and 25 mmol/L histidine were incubated with 50μL Fe<sup>3+</su...Objective:To investigate the effect of oxidized transitional metal（ferric and cupric） ions on the amino acids.Methods:25 mmol/L hydroxyproline and 25 mmol/L histidine were incubated with 50μL Fe<sup>3+</sup> and Cu<sup>2+</sup> ions at pH 7.4 and 37℃for 30 mins in separate test tubes.Then 500μL of 1% thiobarbituricacid（TBA） was added to the incubated amino acids followed by addition of 500μL of glacial acetic acid.The resultant mixture was vortexed and heated at 100℃for 30 min.Absorbance readings were noted after cooling to room temperature.The experiment was repeated in the presence of various reagents,like hydroxyl radical scavengers,antioxidant enzymes,and reducing agents and metal ion chelators.Results:The pink chromogen formed with the absorbance maxima at 524 nm,AND shifted to 560 nm in alkaline pH.The absorbance was expressed as TBAadduct in MDA units.The TBA-adduct decreased in the presence of reducing agents and metal ion chelators.Antioxidant enzymes and hydroxyl radical scavengers did not show any effect. Conclusion:Transitional metal ions in their oxidized state showed significant damage to amino acids,hydroxyproline and histidine.The results indicate the possible role played by high-valent oxo-iron species,ferryl and perferry radicals in damaging biomolecules.展开更多
Virgin coconut meal (VCM) was used for the development of ready-to-eat Indian traditional sweet meat commonly known as “ladoo” both with and without sorbic acid (0.3%). The different ingredients were optimized follo...Virgin coconut meal (VCM) was used for the development of ready-to-eat Indian traditional sweet meat commonly known as “ladoo” both with and without sorbic acid (0.3%). The different ingredients were optimized following re-sponse surface methodology with three independent variables i.e. sugar, water and VCM and sensory attributes as responses. The changes in the quality of VCM ladoo packed in polypropylene (PP, 75 μ) and laminates of metalized polyester (MP, 75 μ) were monitored during storage to establish the shelf life under ambient temperature conditions (15?C - 34?C). Samples without added potassium sorbate spoiled within three weeks of storage due to mold growth and fermented odour. VCM ladoo containing sorbic acid did not support any microbial growth during storage up to 4 months, however, during storage samples packed in PP lost moisture and became hard and brittle, while those packed in MP remained soft. Peroxide and thiobarbituric acid values were higher in PP packed samples as compared to those packed in MP. Sorbic acid degraded during storage of ladoo and the rate of degradation was higher in PP packed ladoos than that in MP packed ones.展开更多
Oxidative reactions are key part of the stress response in marine organisms, which are exposed to a wide variety of environmental stressors. Lipid peroxidation (LPO) occurs in response to oxidant attack, giving rise t...Oxidative reactions are key part of the stress response in marine organisms, which are exposed to a wide variety of environmental stressors. Lipid peroxidation (LPO) occurs in response to oxidant attack, giving rise to unsaturated aldehydes as malondialdehyde (MDA), the main biomarker for LPO assessment. Levels of MDA are measured in biological samples of different fish matrices to determine the oxidative effect of physical or chemical agents, particularly represented by metals. The most used assay is the spectrophotometric determination of thiobarbituric acid (TBA) as MDA-TBA2 adduct. Selectivity is enhanced by separating the adduct by chromatographic methods such as high-performance liquid chromatography or by using alternative derivatization reagents. Because, in biological organism, MDA is found free or protein bound, the two forms should be measured, and the extraction procedures are a crucial step in the processing of the biological sample. This review focused on MDA determination procedures used to assess the effect of experimental and environmental stress induced in fish.展开更多
The relationships among desiccation sensitivities of Antiaris toxicaria seeds and axes, changes in activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, catalase （CAT）, glutathione reductase （GR...The relationships among desiccation sensitivities of Antiaris toxicaria seeds and axes, changes in activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, catalase （CAT）, glutathione reductase （GR） and dehydroascorbate reductase, （DHAR）, production rate of superoxide radical （.O2^-）, and the contents of hydrogen peroxide （H2O2） and thiobarbituric acid （TBA）-reactive substance were studied. Desiccation tolerance of seeds and axes decreased with dehydration. Desiccation tolerance of axes was higher than that of seeds, and that of epicotyls was higher than radicles. Activities of SOD, CAT and DHAR of seeds increased during the initial phase of dehydration, and then decreased with further dehydration, whereas activities of APX and GR decreased with dehydration. These five enzyme activities of axes, however, increased during the initial phase of dehydration, and then decreased with further dehydration. The rate of superoxide radical production, and the contents of H2O2 and TBA-reacUve products of seeds and axes gradually increased with dehydration. These results show that the A. toxicaria seed is a typical recalcitrant seed. Loss of desiccation tolerance in seeds and axes was correlated with the increase in .O2- production rate, content of H2O2 and TBA-reactive products, and the decline of antioxidant enzyme activities of seeds and axes.展开更多
Objective:To assess potential of quercetin and etodolac to treat oxidative stress in neuronal death and inflammation in Alzheimer’s disease of AlCl3 induced rat models.All results of this AlCl_(3)model are compared w...Objective:To assess potential of quercetin and etodolac to treat oxidative stress in neuronal death and inflammation in Alzheimer’s disease of AlCl3 induced rat models.All results of this AlCl_(3)model are compared with those obtained in controls.Methods:Wistar rats,housed in a controlled environment were treated with aluminum chloride(4.2 mg/kg of body weight,i.p.)for 28 d rather than oral to ensure neurotoxic concentration in hippocampus and hypothalamic region,part highly active in memory control and cognition,while control group was injected with saline.Estimation of thiobarbituric acid reactive substance,superoxide dismutase,reduced glutathione and acetylcholine levels gave estimation of neuronal damage.Low(20 mg/kg and 25 mg/kg)and high(40 mg/kg and 50 mg/kg)doses of quercetin and etodolac were administered to the test groups respectively.Histopathology study was conducted to perform relative study.Results:Co-administration of quercetin and etodolac either alone or in combination prevented the changes in biochemical markers of Alzheimer’s disease,but significant results(P<0.05)were seen when a combination of two was administered at low dose levels.Good correlation was developed between chemical estimations and histopathology study.Conclusions:Our findings suggest a combined role of anti-oxidant and cyclooxygenase inhibitor in protection of neural degeneration and inflammation due to oxidative stress.展开更多
文摘In search for new potential inhibitors some new fluorine substituted thiobarbituric acid derivatives (2-4, 7, 8) and their fused/isolated heterobicyclic nitrogen systems (5, 6, 9, 10, 11, 12) have been synthesized from heterocyclization of fluorinated 1,3-diketoamine (1) with CS2 followed by ring closure reactions with primary nitrogen reagents. Structures of the targets have been established from elemental analysis and spectral data. Some synthesized systems have been evaluated as anti-HIV-1 and of cyclin-dependent kinase 2 (CDK2) for cell tumor division.
文摘Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metaI ions, in most of the studied chelates, and that the two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 were coordinated either in the enol or the keto form. IR spetra also showed that Fe(III)-, Ni(II)-, Mn(II)-, VO(II)-L1 and Cu(II)-L2 chelates behaved in a bidentate manner, in contrast with the two (1:1) M:L cobalt chelates with the two ligands are tridentate.TG analysis indicated the presence of three to twelve water molecules of hydration eliminated on heating up to 150℃ and one or two coordinated water molecules removed at 150~180℃.The octahedral structure is proposed fOr all the chelates, except Cu(II)-L2 and Ni(II)-L1 chelates which have square planar geometry, based on their electronic spectra
基金the Natural Science Foundation of Shaan’xi Province(No.2000H03)for support of this work.
文摘A series of 5-arylidene thiobarbituric acids were prepared from aromatic aldehydes and thiobarbituric acid in water without catalyst conditions in good yields. The structures were characterized by elemental analysis, IR and 1H NMR spectra.
文摘AIM: Oxygen free radical mediated tissue damage is well established in pathogenesis of acute pancreatitis (AP).Whether nitric oxide (NO) plays a deleterious or a protective role is unknown. In alcohol-induced AP, we studied NO, lipooxidative damage and glutathione in pancreas, lung and circulation.METHODS: AP was induced in rats (n = 25) by injection of ethyl alcohol into the common biliary duct. A sham laparatomy was performed in controls (n = 15). After 24 h the animals were killed, blood and tissue sampling were done.RESULTS: Histopathologic evidence confirmed the development of AP. Marked changes were observed in the pulmonary tissue. Compared with controls, the AP group displayed higher values for NO metabolites in pancreas and lungs, and thiobarbituric acid reactive substances in circulation. Glutathione was lower in pancreas and in circulation. Glutathione and NO were positively correlated in pancreas and lungs of controls but negatively correlated in circulation of experimental group. In the experimental group, plasma thiobarbituric acid reactive substances were negatively correlated with pancreas thiobarbituric acid reactive substances but positively correlated with pancreas NO.CONCLUSION: NO increases in both pancreas and lungs in AP and NO contributes to the pathogenesis of AP under oxidative stress.
文摘AIM: To examine the protective effect of estradiol on the cultured hepatocytes under oxidative stress. METHODS: Hepatocytes of rat were isolated by using perfusion method, and oxidative stress was induced by a serum-free medium and FeNTA. MDA level was determined with TBA method. Cell damage was assessed by LDH assay. Apoptosis of hepatocytes was assessed with cytoflowmetric analysis. Expression of Bcl-xl in cultured hepatocytes was detected by Western blot. The radical-scavenging activity of estradiol was valued by its ability to scavenge the stable free radical of DDPH. RESULTS: Oxidative stress increased LDH from 168 +/- 25 x 10(-6)IU.cell(-1) to 780 +/- 62 x 10(-6)IU.cell(-1) and MDA(from 0.28 +/- 0.07 x 10(-6)nmol.cell(-1) to 1.35 +/- 0.12 x 10(-6)nmol.cell(-1)) levels in cultured hepatocyte, and estradiol inhibited both LDH and MDA production in a dose dependent manner. In the presence of estradiol 10(-6)mol.L(-1), 10( -7 )mol.L(-1) and 10(-8)mol.L(-1),the LDH levels are 410 +/- 53 x 10(-6)IU.cell(-1) (P【0.01 vs oxidative group), 530 +/- 37 X 10(-6)IU.cell(-1 ) (P【0.01 vs oxidative group), 687+/-42 x 10(-6)IU.cell(-1) (P【0.05 vs oxidative group) respectively, and the MDA level are 0.71+/-0.12 x 10(-6)nmol.cell(-1) (P【0.01 vs oxidative group),0.97+/-0.11 x 10(-6)nmol.cell(-1 )(P【0.01 vs oxidative group) and 1.27+/-0.19 x 10(-6)nmol.cell(-1) respectively. Estradiol suppressed apoptosis of hepatocytes induced by oxidative stress, administration of estradiol(10(-6)mol/L)decreased the apoptotic rate of hepatocytes under oxidative stress from 18.6 +/- 1.2% to 6.5 +/-2.5%, P【0.01. Bcl-xl expression was related to the degree of liver cell damage due to oxidative stress, and estradiol showed a protective action. CONCLUSION: Estradiol protects hepatocytes from oxidative damage by means of its antioxidant activity.
基金the research Fund of the University of Istanbul.No: T-589/240698
文摘AIM: There is increasing evidence that alcohol-induced liverdamage may be associated with increased oxidative stress.We aimed to investigate free-radical scavenger effect of n-acetylcysteine in rats intragastrically fed with ethanol.METHODS: Twenty-four rats divided into three groups werefed 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 weresacrificed under ether anesthesia, intracardiac blood andliver tissues were obtained. Measurements were performedboth in serum and in homogenized liver tissues.Malondialdehyde (MDA) level was measured by TBARSmethod. Glutathione peroxidase (GSH-Px) and superoxidedismutase (SOD) levels were studied by commercial kits.Kruskal-Wallis test was used for statistical analysis.RESULTS: ALT and AST in Group 1 (154 U/Land 302 U/L,respectively) were higher than those in Group 2 (94 U/L and155 U/L) and Group 3 (99 U/L and 168 U/L) (P＝0.001 forboth). Serum and tissue levels of MDA in Group 1 (1.84 nmol/mL and 96 nmol/100 mg-protein) were higher than 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 forboth). On the other hand, serum GSH-Px level in Group 1(8.21 U/g-Hb) was lower than Group 2 (16 U/g-Hb) andGroup 3 (16 U/g-Hb) (P＜0.001). Serum and liver tissue levelsof SOD in Group 1 (11 U/mL and 26 U/100 mg-protein)were lower than Group 2 (18 U/mL and 60 U/100 mg-protein)and Group 3 (20 U/mL and 60 U/100 mg-protein) (P＜0.001for both).CONCLUSION: This study demonstrated that ethanol-induced liver damage is associated with oxidative stress,and co-administration of n-acetylcysteine attenuates thisdamage effectively in rat model.
基金Supported by a grant from the Dutch Foundation of Digestive Diseases
文摘AIM: To assess the levels of antioxidant capacity and oxidative damage in blood of chronic pancreatitis (CP) patients in comparison with those in healthy control sub- jects, by using several different analytical techniques. METHODS: Thirty-five CP patients and 35 healthy con- trol subjects were investigated prospectively with re- spect to plasma levels of thiols, ferric reducing ability of plasma (FRAP, i.e. antioxidant capacity), levels of protein carbonyls and thiobarbituric acid reactive substances (TBARS). Additionally, we evaluated the production of reactive oxygen species (ROS) in whole blood. RESULTS: The antioxidative thiols including cysteine, cysteinylglycine and glutathione were significantly lower in CP patients. In addition, the non-enzymatic antioxi- dant capacity was significantly lower in CP patients, which correlated with the amount of oxidative protein (protein carbonyls) and the extent of lipid damage (TBARS), both were significantly higher in CP patients. The ROS production in whole blood after stimulation with phorbol 12-myritate 13-acetaat, demonstrated a strong tendency to produce more ROS in CP patients. CONCLUSION: Oxidative stress may contribute to the pathogenesis of chronic pancreatitis by decreasing anti- oxidant capacity and increasing oxidative damage in CP patients may be a rationale for intervention with antioxi- dant therapy.
文摘Sodium erythorbate, antioxidant and curing accelerator, used in meat products, have no vitamin functionality. Ascorbic acid （AA）, in contrast, is a powerful antioxidant, but very unstable. The application of encapsulated AA in frankfurters could allow the incorporation of an antioxidant with vitamin functionality and improved stability. The aim of this study was to evaluate the application ofAA microcapsules in frankfurters and the effects of their application on the product. Different analyses were conducted. The values obtained for mass loss, moisture content, water activity, pH and instrumental color were not significantly different among the treatments. The frankfurters containing the microcapsutes exhibited the lowest hardness value （approximately 5,000 g）, resulting in better scores in the sensory analysis. It was possible to apply the AA microcapsules without compromising the oxidative stability and physicochemical characteristics of the product, providing a promising method for protecting AA and producing fortified frankfurters.
基金supported by the Special Fund for Public Welfare Industry of Ministry of Water Resources of China(Grant No201001056)the Project of Jiangxi Provincial Department of Science and Technology (Grant No2010BSA20300)the Project of Jiangxi Provincial Department of Education(Grants No GJJ11246 and GJJ11636)
文摘The freshwater fish Carassius auratus was chosen as an experimental subject, and their hepatic biochemical responses to the medium-term exposure of Benzo（k）fluoranthene （BkF） alone and in combination with PCB 118 and dichlorodiphenyltrichloroethane （DDT） were investigated by measuring the reduced glutathione （GSH）, glutathione S-transferase （GST）, and thiobarbituric acid reactive substances （TBARS）, to assess sublethal effects. The hepatic GSH content was significantly inhibited by organic pollutants, alone and in mixtures, while the TBARS content was significantly induced after three days of exposure. Bell-shaped concentration-response charts of GST activities were obtained. Significant dose-response relationships were found for hepatic GSH and TBARS contents of all concentrations and for the GST activity, except at the highest concentration. The GSH content, GST activity, and TBARS content in Carassius auratus were confirmed as useful biomarkers of exposure to organic pollutions.
基金HEC Pakistan, Department of Chemistry, COMSATS Abbottabad,for this project
文摘Bis-thiobarbiturate derivatives 1-15 have been synthesized, characterized by 1HNMR and El-MS and screened for urease inhibition. All compounds showed various degree of urease inhibitory activity with iC50 values ranging 7.45 ± 0.12 - 74.24 ± 0.81 μmol/L while the standard thiourea behaved normally （ICso = 21.10 ±0.12）. Compounds I （IC50= 7.45 ± 0.12 ]μmol/L）, 9 （IC50 =18,17 ± 1.03 bmol/L） and 13 （IC50= 8.61 ± 0.45 bmol/L） showed excellent urease inhibitory activity in the series. Molecular modeling studies were performed to understand the binding site with the bimetallic nickel center of the enzyme. Structure-activity relationship has also been established for these compounds. This study identified bis- thiobarbiturate as a novel class of urease inhibitors.
文摘The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species （TBARS） assay, total phenol content, evaluation of reactive oxygen species （ROS） in liver mitochondria, Fe2＋ chelating and 2,2-diphenyl-lpicrylhydrazyl （DPPH） scavenging activities. Both extracts had high antioxidant properties and could inhibit FeE＋ and sodium nitroprusside lipid peroxidation in the liver. Total phenol content of ethyl acetate fraction and aqueous extract were 4.50 ±2.26 and 1.21±3.12 mg/g, respectively. Both extracts had a maximal effect at the lowest concentrations tested （15 μg/mL for ethyl acetate and 150 μg/mL for the aqueous）. Ethyl acetate fraction showed that the highest values of antioxidant activity is probably associated with its high phenolic content, Fe2＋ chelating and DPPH scavenging activities. It is therefore concluded that ethyl acetate fraction and to a less extent the aqueous fractions are potent inhibitor of lipid peroxidation.
文摘Objective:To investigate the effect of oxidized transitional metal（ferric and cupric） ions on the amino acids.Methods:25 mmol/L hydroxyproline and 25 mmol/L histidine were incubated with 50μL Fe<sup>3+</sup> and Cu<sup>2+</sup> ions at pH 7.4 and 37℃for 30 mins in separate test tubes.Then 500μL of 1% thiobarbituricacid（TBA） was added to the incubated amino acids followed by addition of 500μL of glacial acetic acid.The resultant mixture was vortexed and heated at 100℃for 30 min.Absorbance readings were noted after cooling to room temperature.The experiment was repeated in the presence of various reagents,like hydroxyl radical scavengers,antioxidant enzymes,and reducing agents and metal ion chelators.Results:The pink chromogen formed with the absorbance maxima at 524 nm,AND shifted to 560 nm in alkaline pH.The absorbance was expressed as TBAadduct in MDA units.The TBA-adduct decreased in the presence of reducing agents and metal ion chelators.Antioxidant enzymes and hydroxyl radical scavengers did not show any effect. Conclusion:Transitional metal ions in their oxidized state showed significant damage to amino acids,hydroxyproline and histidine.The results indicate the possible role played by high-valent oxo-iron species,ferryl and perferry radicals in damaging biomolecules.
文摘Virgin coconut meal (VCM) was used for the development of ready-to-eat Indian traditional sweet meat commonly known as “ladoo” both with and without sorbic acid (0.3%). The different ingredients were optimized following re-sponse surface methodology with three independent variables i.e. sugar, water and VCM and sensory attributes as responses. The changes in the quality of VCM ladoo packed in polypropylene (PP, 75 μ) and laminates of metalized polyester (MP, 75 μ) were monitored during storage to establish the shelf life under ambient temperature conditions (15?C - 34?C). Samples without added potassium sorbate spoiled within three weeks of storage due to mold growth and fermented odour. VCM ladoo containing sorbic acid did not support any microbial growth during storage up to 4 months, however, during storage samples packed in PP lost moisture and became hard and brittle, while those packed in MP remained soft. Peroxide and thiobarbituric acid values were higher in PP packed samples as compared to those packed in MP. Sorbic acid degraded during storage of ladoo and the rate of degradation was higher in PP packed ladoos than that in MP packed ones.
文摘Oxidative reactions are key part of the stress response in marine organisms, which are exposed to a wide variety of environmental stressors. Lipid peroxidation (LPO) occurs in response to oxidant attack, giving rise to unsaturated aldehydes as malondialdehyde (MDA), the main biomarker for LPO assessment. Levels of MDA are measured in biological samples of different fish matrices to determine the oxidative effect of physical or chemical agents, particularly represented by metals. The most used assay is the spectrophotometric determination of thiobarbituric acid (TBA) as MDA-TBA2 adduct. Selectivity is enhanced by separating the adduct by chromatographic methods such as high-performance liquid chromatography or by using alternative derivatization reagents. Because, in biological organism, MDA is found free or protein bound, the two forms should be measured, and the extraction procedures are a crucial step in the processing of the biological sample. This review focused on MDA determination procedures used to assess the effect of experimental and environmental stress induced in fish.
基金Supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (KSCX2-YW-Z-058)the National Natural Science Foundation of China (30470183).
文摘The relationships among desiccation sensitivities of Antiaris toxicaria seeds and axes, changes in activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, catalase （CAT）, glutathione reductase （GR） and dehydroascorbate reductase, （DHAR）, production rate of superoxide radical （.O2^-）, and the contents of hydrogen peroxide （H2O2） and thiobarbituric acid （TBA）-reactive substance were studied. Desiccation tolerance of seeds and axes decreased with dehydration. Desiccation tolerance of axes was higher than that of seeds, and that of epicotyls was higher than radicles. Activities of SOD, CAT and DHAR of seeds increased during the initial phase of dehydration, and then decreased with further dehydration, whereas activities of APX and GR decreased with dehydration. These five enzyme activities of axes, however, increased during the initial phase of dehydration, and then decreased with further dehydration. The rate of superoxide radical production, and the contents of H2O2 and TBA-reacUve products of seeds and axes gradually increased with dehydration. These results show that the A. toxicaria seed is a typical recalcitrant seed. Loss of desiccation tolerance in seeds and axes was correlated with the increase in .O2- production rate, content of H2O2 and TBA-reactive products, and the decline of antioxidant enzyme activities of seeds and axes.
基金Supported by ASBASJS Memorial College of Pharmacy Bela,Ropar(Punjab)(Grant No.ASBASJSCOP/PTU PROJ/AR/2010-2011/09).
文摘Objective:To assess potential of quercetin and etodolac to treat oxidative stress in neuronal death and inflammation in Alzheimer’s disease of AlCl3 induced rat models.All results of this AlCl_(3)model are compared with those obtained in controls.Methods:Wistar rats,housed in a controlled environment were treated with aluminum chloride(4.2 mg/kg of body weight,i.p.)for 28 d rather than oral to ensure neurotoxic concentration in hippocampus and hypothalamic region,part highly active in memory control and cognition,while control group was injected with saline.Estimation of thiobarbituric acid reactive substance,superoxide dismutase,reduced glutathione and acetylcholine levels gave estimation of neuronal damage.Low(20 mg/kg and 25 mg/kg)and high(40 mg/kg and 50 mg/kg)doses of quercetin and etodolac were administered to the test groups respectively.Histopathology study was conducted to perform relative study.Results:Co-administration of quercetin and etodolac either alone or in combination prevented the changes in biochemical markers of Alzheimer’s disease,but significant results(P<0.05)were seen when a combination of two was administered at low dose levels.Good correlation was developed between chemical estimations and histopathology study.Conclusions:Our findings suggest a combined role of anti-oxidant and cyclooxygenase inhibitor in protection of neural degeneration and inflammation due to oxidative stress.
