Remote control enzyme technology is widely used today through resonance. In this study, we showed that the use of frequencies of the catalase enzyme itself to increase enzymatic rate is successful not only in test tub...Remote control enzyme technology is widely used today through resonance. In this study, we showed that the use of frequencies of the catalase enzyme itself to increase enzymatic rate is successful not only in test tubes but also remotely. The present study also suggests that, under optimal temperature, the use of bovine catalase frequency (the specific frequency of that enzyme) has a superior rate promoting vibration than the human catalase frequency, and so increases very significantly the chemical rate of bovine catalase (about 120% at 40˚C). It also suggests that bovine catalase subjected to bovine and human frequencies with catalase bound NADP+ experienced more resonance weight towards NADP+ and so were more slowly reduced back to catalase bound NADPH, increasing compound II formation rate, and slowing down the catalase activity rate.展开更多
Catalase is an enzyme that scavenges hydrogen peroxide in the body and has the role of protecting the organism from oxidative stress. Since catalase activity is associated with various diseases, including diabetes, sk...Catalase is an enzyme that scavenges hydrogen peroxide in the body and has the role of protecting the organism from oxidative stress. Since catalase activity is associated with various diseases, including diabetes, skin diseases like vitiligo, renal failure, and heart failure, it is important to measure its activity. However, it has been difficult to accurately evaluate catalase activity alone, because there are other substances in vivo, such as iron ions, that decompose hydrogen peroxide in addition to catalase. To solve this problem, we conducted a study to develop a method to correctly measure catalase activity from samples containing impurities with hydrogen peroxide removal activity. In this study, catalase inhibitors were added to bovine catalase solution, ferric chloride solution, cell lysates of control cells and experimentally generated catalase knockdown cells (CAT KD), and these mixtures were reacted with hydrogen peroxide to determine the percentage of hydrogen peroxide remaining in the reaction solution after a certain time. The catalase inhibitors used, 3-amino-1H-1,2,4-triazole (3-AT) and sodium azide (NaN3), inhibited the removal of hydrogen peroxide by bovine catalase at a high rate in in-vitro experiments. However, these catalase inhibitors did not inhibit hydrogen peroxide removal in the Fenton reaction of iron ion and hydrogen peroxide in in-vitro experiments. On the other hand, hydrogen peroxide removal by cell lysate was inhibited by the addition of 3-AT or NaN3. The inhibitory effect was equivalent or superior to that of CAT KD cells, in which catalase was experimentally knocked down. These results suggested that 3-AT and NaN3 specifically inhibit hydrogen peroxide removal of catalase. Through these studies, we found that when cell lysate with a catalase inhibitor was mixed with hydrogen peroxide, hydrogen peroxide that was not removed by catalase inhibition remained in the test tube after a certain time, and this residual hydrogen peroxide reflected the hydrogen peroxide removal activity of catalase. By measuring this unremoved hydrogen peroxide, it was possible to evaluate catalase activity from samples containing impurities that have hydrogen peroxide removal properties.展开更多
[Objective] This work was aimed to explore the mechanism of Hg2+ toxicity on plants.[Method]Activities of peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)were investigated in wheat(Triticum aestivum L.)seedl...[Objective] This work was aimed to explore the mechanism of Hg2+ toxicity on plants.[Method]Activities of peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)were investigated in wheat(Triticum aestivum L.)seedlings under Hg2+ stress at different concentrations.[Result]① There were no obvious effects on the growth of seedlings when the concentration of Hg2+ was lower than 0.10 mmol/L.However,toxic effects on the growth of seedling were observed when the concentration of Hg2+ was higher than 0.10 mmol/L.② Different tissues showed different resistant ability in response to Hg2+ stress.The leaves and roots of wheat seedlings were more insensitive to Hg2+ toxicity.③ CAT was more sensitive to Hg2+ stress compared to POD and SOD.[Conclusion]The toxic effect was related to the concentration of Hg2+(0.10 mmol/L).The higher concentration of Hg2+ could affect the expression of POD,CAT,and SOD isozymes in the leaves,roots of wheat seedlings and germinated seeds,which further affect the normal metabolism of membrane lipid and inhibit the growth of wheat seedlings at last.展开更多
Two different cDNA clones (Sscat1 and Sscat2) encoding catalase, the primary important H2O2-scavenging enzyme, were isolated from a AZap-cDNA library constructed from a 400 mmol/L NaCl-treated library of Suaeda salsa ...Two different cDNA clones (Sscat1 and Sscat2) encoding catalase, the primary important H2O2-scavenging enzyme, were isolated from a AZap-cDNA library constructed from a 400 mmol/L NaCl-treated library of Suaeda salsa ( L.) Pall aerial tissue. Sscat1 (1.7 kb) contains a full open reading frame of 492 amino acids and Sscat2 (1.1 kb) is a partial clone. BLAST analysis indicates that the two clones share 71.9% identity in nucleotide sequence and 75% identity in deduced amino acid sequence within the last 287 amino acid residues of Sscat1. Southern blotting analysis showed that Sscat1 is multicopy in S. salsa genome, while Sscat2 is a single copy gene. Northern blotting analysis showed a rapid increase in the steady-level of both genes in roots after 48 It salt treatment, but only Sscat1 was induced in salinity treated leaves. Time-course analysis carried out in leaves confirmed that Sscat1 was induced by salt stress, in contrast to Sscat2. These implied that the expression of Sscat1 and Sscat2 genes are differentially regulated in S. salsa. The activity of total catalase is dramatically increased in response to salt stress.展开更多
[Objective] The research aimed to study the correlations between catalase（CAT） and ascorbate peroxidase（ASP） and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua ...[Objective] The research aimed to study the correlations between catalase（CAT） and ascorbate peroxidase（ASP） and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua No.11 as materials,the changes of rice seedlings under the treatment conditions of Cd,Cd＋CAT inhibitor,Cd＋APX inhibitor were studied.[Result] Under Cd stress,inhibition of CAT activity caused the significant inhibition on the growth of aerial parts,decreased the number of adventitious roots and lateral roots,but it can significant promote the elongation growth of adventitious roots and lateral roots.Moreover,the length of the first lateral root from root tip on the primary roots and adventitious roots was also increased than control.When APX activity was inhibited,the growth changes of rice were similar with that treated by CAT inhibitor.[Conclusion] CAT and APX may play important roles in the regulation of rice root system growth in both non-stress and Cd-stressed rice展开更多
The impact of chromium（Ⅲ） and （Ⅵ） forms on soil catalase activity was presented. The Orthic Podzol, Haplic Phaeozem and Mollic Gleysol from different depths were used in the experiment. The soil samples were ame...The impact of chromium（Ⅲ） and （Ⅵ） forms on soil catalase activity was presented. The Orthic Podzol, Haplic Phaeozem and Mollic Gleysol from different depths were used in the experiment. The soil samples were amended with solution of Cr（Ⅲ） using CrCl3, and with Cr（Ⅵ） using K2Cr2O7 in the concentration range from 0 to 20 mg/kg, whereas the samples without the addition of chromium served as control. Catalase activity was assayed by one of the commonly used spectrophotometric methods. As it was demonstrated in the experiment, both Cr（Ⅲ） and Cr（Ⅵ） have an ability to reduce soil catalase activity. A chromium dosage of 20 mg/kg caused the inhibition of catalase activity and the corresponding contamination levels ranged from 75% to 92% for Cr（Ⅲ） and 68% to 76% for Cr（Ⅵ）, with relation to the control. Catalase activity reached maximum in the soil material from surface layers （0-25 cm）, typically characterized by the highest content of organic matter creating favorable conditions for microorganisms.展开更多
Objective:To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation,changes in catalase activities and hepatic biochemical marker levels in blood plasma.Meth...Objective:To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation,changes in catalase activities and hepatic biochemical marker levels in blood plasma.Methods:Oxidative stress was induced by oral administration of ethanol(20%w/v) at a dosage of 5 niL/kg bw in rats.After 28 days of treatment,the rats were fasted overnight and sacrificed by cervical dislocation.Blood was collected with a 2 mL syringe by cardiac puncture and was centrifuged at 3000 rpm for 10 min.The plasma was analyzed to evaluate malondialdehyde(MDA),catalase activity,aspartate aminotransferase(AST),alkaline phosphatase(ALP) and alanine aminotransferase(ALT) concentrations.Results:Administration of alcohol caused a drastic increase(87.74%) in MDA level compared with the control.Pineapple peel extract significantly reduced the MDA level by 60.16%at 2.S mL/kg bw.Rats fed alcohol only had the highest catalase activity,treatment with pineapple peel extract at 2.5 mL/kg bw however, reduced the activity.Increased AST,ALP and ALT activities were observed in rats fed alcohol only respectively,treatment with pineapple peel extract drastically reduced their activities. Conclusions:The positive modulation of lipid peroxidation,catalase activities as well as hepatic biomarker levels of blood plasma by the methanolic extract of pineapple peels under alcoholinduced oxidative stress is an indication of its protective ability in the management of alcoholinduced toxicity.展开更多
Total dissolved gas supersaturation(TDGS) appears when the pressures of gases in a solution exceed the barometric pressures.TDGS is often caused by flood discharge at dams.It may lead to gas bubble disease(GBD) for fi...Total dissolved gas supersaturation(TDGS) appears when the pressures of gases in a solution exceed the barometric pressures.TDGS is often caused by flood discharge at dams.It may lead to gas bubble disease(GBD) for fish and biochemical responses of selected fish and other aquatic organisms.The purpose of this study was to determine the impact of long-term TDGS levels on the growth and biochemical responses of rock carp(Procypris rabaudi Tchang) dwelling in the upper reaches of the Yangtze River.Three-year-old rock carp were exposed to TDGS levels at 100%,104%,108%,112%,and 116% for 42 d.Samples were taken every 7 d after the start of the trial in order to determine catalase(CAT) and superoxide dismutase(SOD) activities in gill and muscle tissues.Samples were taken at Days 0 and 42 of exposure to determine growth rate.Little effect was found on growth rate in all treatment groups.SOD and CAT activities varied in different tissues,according to time of exposure and TDGS levels.The biochemical response of fish exposed to TDGS was more obvious in gill tissue than in muscle tissue.Surveys of SOD and CAT activities in different tissues offer important information about the effect of TDGS on the rare fish in the Yangtze River,and may help evaluate the risk to the aquatic eco-environment and aquatic ecosystem in the downstream of the Yangtze River.展开更多
Total dissolved gas(TDG) supersaturation caused by dam sluicing can result in gas bubble trauma(GBT) in fish and threaten their survival.In the present study,Chinese suckers(Myxocyprinus asiaticus Bleeker) were expose...Total dissolved gas(TDG) supersaturation caused by dam sluicing can result in gas bubble trauma(GBT) in fish and threaten their survival.In the present study,Chinese suckers(Myxocyprinus asiaticus Bleeker) were exposed to TDG supersaturated water at levels ranging from 120% to 145% for 48 h.The median lethal concentration(LC 50) and the median lethal time(LT 50) were determined to evaluate acute lethal effects on Chinese suckers.The results showed that the LC 50 values of 4,6,8,and 10 h were 142%,137%,135%,and 130%,respectively.The LT 50 values were 3.2,4.7,7.8,9.2,and 43.4 h,respectively,when TDG supersaturated levels were 145%,140%,135%,130%,and 125%.Furthermore,the biological responses in Chinese suckers were studied by assaying the catalase(CAT) activities in gills and muscles at the supersaturation level of 140% within LT 50.The CAT activities in the gills and muscle tissues exhibited a regularity of a decrease after an increase.CAT activities in the muscles were increased significantly at 3/5LT 50(P<0.05) and then came back to the normal level.However,there were no significant differences between the treatment group(TDG level of 140%) and the control group(TDG level of 100%) on CAT activities in the gills before 3/5LT 50(P>0.05),but the activities were significantly lower than the normal level at 4/5LT 50 and LT 50(P<0.05).展开更多
Various inflammatory stimuli are able to modify or even"re-program"the mitochondrial metabolism that results in generation of reactive oxygen species.In noncommunicable chronic diseases such as atheroscleros...Various inflammatory stimuli are able to modify or even"re-program"the mitochondrial metabolism that results in generation of reactive oxygen species.In noncommunicable chronic diseases such as atherosclerosis and other cardiovascular pathologies,type 2 diabetes and metabolic syndrome,these modifications become systemic and are characterized by chronic inflammation and,in particular,"neuroinflammation"in the central nervous system.The processes associated with chronic inflammation are frequently grouped into"vicious circles"which are able to stimulate each other constantly amplifying the pathological events.These circles are evidently observed in Alzheimer's disease,atherosclerosis,type 2 diabetes,metabolic syndrome and,possibly,other associated pathologies.Furthermore,chronic inflammation in peripheral tissues is frequently concomitant to Alzheimer's disease.This is supposedly associated with some common genetic polymorphisms,for example,Apolipoprotein-Eε4 allele carriers with Alzheimer's disease can also develop atherosclerosis.Notably,in the transgenic mice expressing the recombinant mitochondria targeted catalase,that removes hydrogen peroxide from mitochondria,demonstrates the significant pathology amelioration and health improvements.In addition,the beneficial effects of some natural products from the xanthophyll family,astaxanthin and fucoxanthin,which are able to target the reactive oxygen species at cellular or mitochondrial membranes,have been demonstrated in both animal and human studies.We propose that the normalization of mitochondrial functions could play a key role in the treatment of neurodegenerative disorders and other noncommunicable diseases associated with chronic inflammation in ageing.Furthermore,some prospective drugs based on mitochondria targeted catalase or xanthophylls could be used as an effective treatment of these pathologies,especially at early stages of their development.展开更多
Catalase （CAT） and selenium-dependent glutathione peroxidase （Se-GPx） play a vital role in protecting organisms against various oxidative stresses by eliminating H202, The objective of this paper is to evaluate th...Catalase （CAT） and selenium-dependent glutathione peroxidase （Se-GPx） play a vital role in protecting organisms against various oxidative stresses by eliminating H202, The objective of this paper is to evaluate the roles of these antioxidant molecules in the ridgetail white prawn Exopalaemon carinicauda in response to low salinity stress. A complementary DNA （cDNA） containing the complete coding sequence of CAT was cloned from the hepatopancreas using reverse-transcription polymerase chain reaction （RT-PCR） and rapid amplification of cDNA ends. The full-length cDNA of CAT （2 649 bp） contains a 5＇-untranslated region （UTR） of 78 bp, a 3＇- UTR of 1 017 bp, with a poly （A） tail, and an open reading frame of 1 554 bp encoding a 517-amino-acid polypeptide with predicted molecular mass of 58.46 kDa and estimated isoelectric point of 6.64. This CAT sequence contained the proximal active site signature （60FDRERIPERWHAKGAG76）, proximal heme-ligand signature sequence （350RLFSYPDTH358） and three catalytic amino acid residues （His71, Asn144 and Tyr354）. Sequence comparison showed that the CAT deduced amino acid sequence of E. carinicauda shared 68%-92% of identities with those of other species. Quantitative real-time PCR analysis revealed that CAT mRNA was widely expressed in the hepatopancreas （highest）, hemocyte, eyestalk, heart, gill, muscle, ovary and stomach. Under low salinity stress, CAT and GPx mRNA expression levels both in the gill and hepatopancreas increased significantly at the first 48 h and 6 h respectively, indicating a tissue- and time-dependent antioxidant response in E. carinicauda. All these results indicate that E. carinicauda CAT is a member of the CAT family and might be involved in the acute response against low salinity stress.展开更多
The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of H202 in nico...The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of H202 in nicotinamide adenine dinucleotide phosphate （NADPH） oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac 1 was dependent on the levels of intracellular H202. Puerarin blocked the phosphorylation of extracellular regulated protein kinases （ERK）1/2, abolished activator protein （AP）-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of H202-dependent Racl activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregu- lation of catalase expression and H202-dependent Racl activation.展开更多
OBJECTIVE： This study investigated the effects of allylpyrocatechol （APC）, the major component in ethanolic extract of Piper betle, on key oxidative stress resistance enzymes important for the survival of Staphyloc...OBJECTIVE： This study investigated the effects of allylpyrocatechol （APC）, the major component in ethanolic extract of Piper betle, on key oxidative stress resistance enzymes important for the survival of Staphylococcus aureus, a major pathogen in the human host. METHODS： Effects of APC on expressions of genes encoding catalase （katA）, superoxide dismutases （SODs）, including soda and sodM, and alkyl hydroperoxide reductase （ahpC） in S. aureus were quantitated by RT-qPCR in reference to gyrA and 16S rRNA. Corresponding activities of the enzymes were also investigated. The Livak analysis was performed for verification of gene-fold expression data. Effects of APC on intracellular and extracellular reactive oxygen species （ROS） levels were determined using the nitroblue tetrazolium （NBT） reduction assay. RESULTS： APC-treated S. aureus cells had higher sodA and sodM transcripts at 1.5-fold and 0.7-fold expressions respectively with corresponding increase in total SOD activity of 12.24 U/mL compared to untreated cells, 10.85 U/mL （P〈0.05）. Expression of ahpC was highest in APC-treated cells with 5.5-fold increased expression compared to untreated cells （P〈0.05）. Correspondingly, ahpC activity was higher in APC-treated cells at 0.672 （A310nm） compared to untreated cells which was 0.394 （A310nm）. In contrast, katA expression was 1.48-fold and 0.33-fold lower respectively relative to gyrA and 16S rRNA. Further, APC-treated cells showed decreased catalase activity of 1.8 × 10^-4 （U/L or μmol/（min.L）） compared to untreated cells, which was 4.8 × 10^-4 U/L （P〈0.05）. Absorbance readings （A575nm） for the NBT reduction assay were 0.709 and 0.695 respectively for untreated and treated cells, which indicated the presence of ROS. APC-treated S. aureus cells had lower ROS levels both extracellularly and intracellularly, but larger amounts remained intracellularly compared to extracellular levels with absorbances of 0.457 and 0.137 respectively （P〈0.05）. CONCLUSION： APC induced expressions of both sodA and sodM, resulting in increased total SOD activity in S. aureus. Higher sodA expression indicated stress induced intracellularly involving O2, presumably leading to higher intracellular pools of H2O2. A concommittant decrease in katA expression and catalase activity possibly induced ahpC expression, which was increased the highest in APC-treated cells. Our findings suggest that in the absence of catalase, cells are propelled to seek an alternatepathway involving ahpC to reduce stress invoked by O2- and H2O2. Although APC reduced levels of ROS, significant amounts eluded its antioxidative action and remained intracellularly, which adds to oxidative stress in treated cells.展开更多
Objective This paper aims to assess the interaction between common variations in catalase（CAT） polymorphic gene and environmental factors for antioxidant defense enzyme in modulating individual susceptibility to col...Objective This paper aims to assess the interaction between common variations in catalase（CAT） polymorphic gene and environmental factors for antioxidant defense enzyme in modulating individual susceptibility to colorectal cancer（CRC）.Methods A case-control study with 880 colorectal cancer cases and 848 controls was conducted to investigate whether variations in the catalase（CAT） gene,one of the genes involved in scavenging oxidative stress,influenced susceptibility to CRC.Results The interaction between life style and genotypes as well as with their effects on colorectal cancer was deduced from the present study.Significant difference（P=0.01） was identified in the distribution of CAT genotype between the colorectal cancer cases and the controls.The CRC cases had significantly lower mean activity than the controls（P〈0.01）.Correlation analyses revealed statistically significant correlations between CAT activity and CAT genotype（P〈0.01）.Conclusion The risk of CRC was associated with smoking,low vegetable consumption,high pork and poultry consumptions,and low or high BMI.This is the first study reporting an association of polymorphism CAT-21A〉T with colorectal cancer.Low CAT activity was associated with an increased risk of CRC;however,no evidence was found to support an association between CAT-21A〉T polymorphism and CRC risk.展开更多
BACKGROUND：Mailuoning, a Chinese herb, has been widely used in China to treat acute ischemic stroke, and the major component exhibits anti-oxidative effects. However, the precise anti-oxidation pathway remains uncert...BACKGROUND：Mailuoning, a Chinese herb, has been widely used in China to treat acute ischemic stroke, and the major component exhibits anti-oxidative effects. However, the precise anti-oxidation pathway remains uncertain.OBJECTIVE：To validate the protective effects of Mailuoning on H202-induced primary cortical neuron injury in embryonic mice.DESIGN, TIME AND SETTING：Comparative observation and in v#ro experiments were performed at the Jiangsu Key Laboratory for Molecular Medicine from January 2008 to September 2009.MATERIALS：Mailuoning （Nanjing Jinling Medical Company, China）, reactive oxygen species （ROS） kit （Beyotime Biotechnology, China）, superoxide dismutase （SOD）, Cu/Zn SOD kit, malondialdehyde （MDA） kits （Nanjing Jiancheng, China）, mitochondrial membrane potential （GMS10013.1, GENMED, USA） and catalase activity assay kit （Beyotime Biotechnology, China） were utilized for the present study.METHODS：Mouse embryonic cortical neurons were isolated and cultured with culture medium containing H2O2 （80 μmol/L） and/or Mailuoning （1.25 μg/mL） for 24 hours.MAIN OUTCOME MEASURES：Neuronal viability and death were detected by methyl thiazolyl tetrazdium and flow cytometry; ROS production was determined by flow cytometry; mitochondriai membrane potential was detected using fluorescent staining; SOD activity was detected using a modified nitroblue tetrazolium method; Cu/Zn SOD and catalase activity was detected by spectrophotometry; and MDA was determined using the lipid peroxidation method.RESULTS：H2O2 increased ROS production and MDA concentration （P 〈 0.05）, and decreased mitochondrial membrane potential, SOD, Cu/Zn SOD and catalase activity （P 〈 0.05）; the number of surviving neurons （P 〈 0.05） was also reduced. Mai/uoning reversed these changes.CONCLUSION：Mailuoning protects H2O2-induced injury in cortical cells by inhibiting ROS and MDA, increasing depolarization of mitochondrial membrane, and enhancing SOD and catalase activity.展开更多
Highly sensitive catalase electrodes for sensing hydrogen peroxide have been fabricated based on polypyrrole films with microcontainers. The microcontainers have a cup-like morphology and are arranged in a density of ...Highly sensitive catalase electrodes for sensing hydrogen peroxide have been fabricated based on polypyrrole films with microcontainers. The microcontainers have a cup-like morphology and are arranged in a density of 4000 units cm^-2. Catalase was immobilized into the polypyrrole films with microcontainers （Ppy-mc）, which were coated on a Pt substrate electrode. The catalase/Ppy-mc/Pt electrode showed linear response to hydrogen peroxide in the range of 0-18 mmol/L at a potential of-0.3 V （versus SCE）. Its sensitivity was measured to be approximately 3.64 μA （mmol/L） ^-1 cm^- 2, which is about two times that of the electrode fabricated from a flat Ppy film （catalase/Ppy-flat/Pt electrode）. The electrode is highly selective for hydrogen peroxide and its sensitivity is interfered by potential interferents such as ascorbic acid, urea and fructose. Furthermore, such catalase electrodes showed long-term storage stability of 15 days under dry conditions at 4℃.展开更多
The advantages of measuring hepatic oxidative status in liver biopsy are that it helps in diagnosis of hepatic dysfunction, reflects the degree of deterioration in the liver tissues, and helps to determine the severit...The advantages of measuring hepatic oxidative status in liver biopsy are that it helps in diagnosis of hepatic dysfunction, reflects the degree of deterioration in the liver tissues, and helps to determine the severity of hepatic injury. We aimed to study the oxidative stress state in children with chronic hepatitis by using indirect approach in which antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) are determined in the liver tissue. The present study included 21 children and adolescents (12 males, 9 females) suffering from chronic hepatitis. Patients were selected from the Hepatology Clinic, New Children’s Hospital, Cairo University from November 2006 till 2009 and compared with a group of 7 children who happened to have incidental normal liver biopsy. Children with chronic hepatitis had mean age 8.12 ± 1.15 years. It was further subdivided into 2 subgroups: chronic viral heaptitis (n = 13) and cryptogenic hepatitis (n = 8). GPX, SOD and CAT levels were measured in fresh liver tissue (cell free homogenates) using ELISA. In chronic hepatitis group;there was a significant increase in the hepatic GPX activity (38.59 ± 35.82 nmol/min/ml) as compared to the control group (10.62 ± 6.68 nmol/min/ml). Also a significant correlation was observed between SOD and both ALT (r = 0.87, p < 0.05) and AST (r = 0.74, p < 0.05). GPX correlated with ALT (r = 0.80, p < 0.05) level in the chronic viral hepatitis subgroup. Our findings suggest that oxidative stress could play a role in the pathogenesis of chronic hepatitis. These preliminary results are encouraging to conduct more extensive clinical studies combining antioxidant therapy with various treatments.展开更多
文摘Remote control enzyme technology is widely used today through resonance. In this study, we showed that the use of frequencies of the catalase enzyme itself to increase enzymatic rate is successful not only in test tubes but also remotely. The present study also suggests that, under optimal temperature, the use of bovine catalase frequency (the specific frequency of that enzyme) has a superior rate promoting vibration than the human catalase frequency, and so increases very significantly the chemical rate of bovine catalase (about 120% at 40˚C). It also suggests that bovine catalase subjected to bovine and human frequencies with catalase bound NADP+ experienced more resonance weight towards NADP+ and so were more slowly reduced back to catalase bound NADPH, increasing compound II formation rate, and slowing down the catalase activity rate.
文摘Catalase is an enzyme that scavenges hydrogen peroxide in the body and has the role of protecting the organism from oxidative stress. Since catalase activity is associated with various diseases, including diabetes, skin diseases like vitiligo, renal failure, and heart failure, it is important to measure its activity. However, it has been difficult to accurately evaluate catalase activity alone, because there are other substances in vivo, such as iron ions, that decompose hydrogen peroxide in addition to catalase. To solve this problem, we conducted a study to develop a method to correctly measure catalase activity from samples containing impurities with hydrogen peroxide removal activity. In this study, catalase inhibitors were added to bovine catalase solution, ferric chloride solution, cell lysates of control cells and experimentally generated catalase knockdown cells (CAT KD), and these mixtures were reacted with hydrogen peroxide to determine the percentage of hydrogen peroxide remaining in the reaction solution after a certain time. The catalase inhibitors used, 3-amino-1H-1,2,4-triazole (3-AT) and sodium azide (NaN3), inhibited the removal of hydrogen peroxide by bovine catalase at a high rate in in-vitro experiments. However, these catalase inhibitors did not inhibit hydrogen peroxide removal in the Fenton reaction of iron ion and hydrogen peroxide in in-vitro experiments. On the other hand, hydrogen peroxide removal by cell lysate was inhibited by the addition of 3-AT or NaN3. The inhibitory effect was equivalent or superior to that of CAT KD cells, in which catalase was experimentally knocked down. These results suggested that 3-AT and NaN3 specifically inhibit hydrogen peroxide removal of catalase. Through these studies, we found that when cell lysate with a catalase inhibitor was mixed with hydrogen peroxide, hydrogen peroxide that was not removed by catalase inhibition remained in the test tube after a certain time, and this residual hydrogen peroxide reflected the hydrogen peroxide removal activity of catalase. By measuring this unremoved hydrogen peroxide, it was possible to evaluate catalase activity from samples containing impurities that have hydrogen peroxide removal properties.
文摘[Objective] This work was aimed to explore the mechanism of Hg2+ toxicity on plants.[Method]Activities of peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)were investigated in wheat(Triticum aestivum L.)seedlings under Hg2+ stress at different concentrations.[Result]① There were no obvious effects on the growth of seedlings when the concentration of Hg2+ was lower than 0.10 mmol/L.However,toxic effects on the growth of seedling were observed when the concentration of Hg2+ was higher than 0.10 mmol/L.② Different tissues showed different resistant ability in response to Hg2+ stress.The leaves and roots of wheat seedlings were more insensitive to Hg2+ toxicity.③ CAT was more sensitive to Hg2+ stress compared to POD and SOD.[Conclusion]The toxic effect was related to the concentration of Hg2+(0.10 mmol/L).The higher concentration of Hg2+ could affect the expression of POD,CAT,and SOD isozymes in the leaves,roots of wheat seedlings and germinated seeds,which further affect the normal metabolism of membrane lipid and inhibit the growth of wheat seedlings at last.
文摘Two different cDNA clones (Sscat1 and Sscat2) encoding catalase, the primary important H2O2-scavenging enzyme, were isolated from a AZap-cDNA library constructed from a 400 mmol/L NaCl-treated library of Suaeda salsa ( L.) Pall aerial tissue. Sscat1 (1.7 kb) contains a full open reading frame of 492 amino acids and Sscat2 (1.1 kb) is a partial clone. BLAST analysis indicates that the two clones share 71.9% identity in nucleotide sequence and 75% identity in deduced amino acid sequence within the last 287 amino acid residues of Sscat1. Southern blotting analysis showed that Sscat1 is multicopy in S. salsa genome, while Sscat2 is a single copy gene. Northern blotting analysis showed a rapid increase in the steady-level of both genes in roots after 48 It salt treatment, but only Sscat1 was induced in salinity treated leaves. Time-course analysis carried out in leaves confirmed that Sscat1 was induced by salt stress, in contrast to Sscat2. These implied that the expression of Sscat1 and Sscat2 genes are differentially regulated in S. salsa. The activity of total catalase is dramatically increased in response to salt stress.
基金Supported by National Natural Science Foundation of China(30671126)~~
文摘[Objective] The research aimed to study the correlations between catalase（CAT） and ascorbate peroxidase（ASP） and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua No.11 as materials,the changes of rice seedlings under the treatment conditions of Cd,Cd＋CAT inhibitor,Cd＋APX inhibitor were studied.[Result] Under Cd stress,inhibition of CAT activity caused the significant inhibition on the growth of aerial parts,decreased the number of adventitious roots and lateral roots,but it can significant promote the elongation growth of adventitious roots and lateral roots.Moreover,the length of the first lateral root from root tip on the primary roots and adventitious roots was also increased than control.When APX activity was inhibited,the growth changes of rice were similar with that treated by CAT inhibitor.[Conclusion] CAT and APX may play important roles in the regulation of rice root system growth in both non-stress and Cd-stressed rice
文摘The impact of chromium（Ⅲ） and （Ⅵ） forms on soil catalase activity was presented. The Orthic Podzol, Haplic Phaeozem and Mollic Gleysol from different depths were used in the experiment. The soil samples were amended with solution of Cr（Ⅲ） using CrCl3, and with Cr（Ⅵ） using K2Cr2O7 in the concentration range from 0 to 20 mg/kg, whereas the samples without the addition of chromium served as control. Catalase activity was assayed by one of the commonly used spectrophotometric methods. As it was demonstrated in the experiment, both Cr（Ⅲ） and Cr（Ⅵ） have an ability to reduce soil catalase activity. A chromium dosage of 20 mg/kg caused the inhibition of catalase activity and the corresponding contamination levels ranged from 75% to 92% for Cr（Ⅲ） and 68% to 76% for Cr（Ⅵ）, with relation to the control. Catalase activity reached maximum in the soil material from surface layers （0-25 cm）, typically characterized by the highest content of organic matter creating favorable conditions for microorganisms.
文摘Objective:To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation,changes in catalase activities and hepatic biochemical marker levels in blood plasma.Methods:Oxidative stress was induced by oral administration of ethanol(20%w/v) at a dosage of 5 niL/kg bw in rats.After 28 days of treatment,the rats were fasted overnight and sacrificed by cervical dislocation.Blood was collected with a 2 mL syringe by cardiac puncture and was centrifuged at 3000 rpm for 10 min.The plasma was analyzed to evaluate malondialdehyde(MDA),catalase activity,aspartate aminotransferase(AST),alkaline phosphatase(ALP) and alanine aminotransferase(ALT) concentrations.Results:Administration of alcohol caused a drastic increase(87.74%) in MDA level compared with the control.Pineapple peel extract significantly reduced the MDA level by 60.16%at 2.S mL/kg bw.Rats fed alcohol only had the highest catalase activity,treatment with pineapple peel extract at 2.5 mL/kg bw however, reduced the activity.Increased AST,ALP and ALT activities were observed in rats fed alcohol only respectively,treatment with pineapple peel extract drastically reduced their activities. Conclusions:The positive modulation of lipid peroxidation,catalase activities as well as hepatic biomarker levels of blood plasma by the methanolic extract of pineapple peels under alcoholinduced oxidative stress is an indication of its protective ability in the management of alcoholinduced toxicity.
基金Project (No. 50979063) supported by the National Natural Science Foundation of China
文摘Total dissolved gas supersaturation(TDGS) appears when the pressures of gases in a solution exceed the barometric pressures.TDGS is often caused by flood discharge at dams.It may lead to gas bubble disease(GBD) for fish and biochemical responses of selected fish and other aquatic organisms.The purpose of this study was to determine the impact of long-term TDGS levels on the growth and biochemical responses of rock carp(Procypris rabaudi Tchang) dwelling in the upper reaches of the Yangtze River.Three-year-old rock carp were exposed to TDGS levels at 100%,104%,108%,112%,and 116% for 42 d.Samples were taken every 7 d after the start of the trial in order to determine catalase(CAT) and superoxide dismutase(SOD) activities in gill and muscle tissues.Samples were taken at Days 0 and 42 of exposure to determine growth rate.Little effect was found on growth rate in all treatment groups.SOD and CAT activities varied in different tissues,according to time of exposure and TDGS levels.The biochemical response of fish exposed to TDGS was more obvious in gill tissue than in muscle tissue.Surveys of SOD and CAT activities in different tissues offer important information about the effect of TDGS on the rare fish in the Yangtze River,and may help evaluate the risk to the aquatic eco-environment and aquatic ecosystem in the downstream of the Yangtze River.
基金Project supported by the National Natural Science Foundation ofChina (No. 50979063)the Scientific Research Foundation for Young Teachers of Xihua University (No. Z1120412),China
文摘Total dissolved gas(TDG) supersaturation caused by dam sluicing can result in gas bubble trauma(GBT) in fish and threaten their survival.In the present study,Chinese suckers(Myxocyprinus asiaticus Bleeker) were exposed to TDG supersaturated water at levels ranging from 120% to 145% for 48 h.The median lethal concentration(LC 50) and the median lethal time(LT 50) were determined to evaluate acute lethal effects on Chinese suckers.The results showed that the LC 50 values of 4,6,8,and 10 h were 142%,137%,135%,and 130%,respectively.The LT 50 values were 3.2,4.7,7.8,9.2,and 43.4 h,respectively,when TDG supersaturated levels were 145%,140%,135%,130%,and 125%.Furthermore,the biological responses in Chinese suckers were studied by assaying the catalase(CAT) activities in gills and muscles at the supersaturation level of 140% within LT 50.The CAT activities in the gills and muscle tissues exhibited a regularity of a decrease after an increase.CAT activities in the muscles were increased significantly at 3/5LT 50(P<0.05) and then came back to the normal level.However,there were no significant differences between the treatment group(TDG level of 140%) and the control group(TDG level of 100%) on CAT activities in the gills before 3/5LT 50(P>0.05),but the activities were significantly lower than the normal level at 4/5LT 50 and LT 50(P<0.05).
文摘Various inflammatory stimuli are able to modify or even"re-program"the mitochondrial metabolism that results in generation of reactive oxygen species.In noncommunicable chronic diseases such as atherosclerosis and other cardiovascular pathologies,type 2 diabetes and metabolic syndrome,these modifications become systemic and are characterized by chronic inflammation and,in particular,"neuroinflammation"in the central nervous system.The processes associated with chronic inflammation are frequently grouped into"vicious circles"which are able to stimulate each other constantly amplifying the pathological events.These circles are evidently observed in Alzheimer's disease,atherosclerosis,type 2 diabetes,metabolic syndrome and,possibly,other associated pathologies.Furthermore,chronic inflammation in peripheral tissues is frequently concomitant to Alzheimer's disease.This is supposedly associated with some common genetic polymorphisms,for example,Apolipoprotein-Eε4 allele carriers with Alzheimer's disease can also develop atherosclerosis.Notably,in the transgenic mice expressing the recombinant mitochondria targeted catalase,that removes hydrogen peroxide from mitochondria,demonstrates the significant pathology amelioration and health improvements.In addition,the beneficial effects of some natural products from the xanthophyll family,astaxanthin and fucoxanthin,which are able to target the reactive oxygen species at cellular or mitochondrial membranes,have been demonstrated in both animal and human studies.We propose that the normalization of mitochondrial functions could play a key role in the treatment of neurodegenerative disorders and other noncommunicable diseases associated with chronic inflammation in ageing.Furthermore,some prospective drugs based on mitochondria targeted catalase or xanthophylls could be used as an effective treatment of these pathologies,especially at early stages of their development.
基金The Modern Agro-industry Technology Research System under contract No.CARS-47the National High-tech R&D Program(863 Program) of China under contract No.2012AA10A409+1 种基金the Special Fund for Independent Innovation of Shandong Province under contract No.2013CX80202the Special Fund for Agro-scientific Research in the Public Interest under contract No.201103034
文摘Catalase （CAT） and selenium-dependent glutathione peroxidase （Se-GPx） play a vital role in protecting organisms against various oxidative stresses by eliminating H202, The objective of this paper is to evaluate the roles of these antioxidant molecules in the ridgetail white prawn Exopalaemon carinicauda in response to low salinity stress. A complementary DNA （cDNA） containing the complete coding sequence of CAT was cloned from the hepatopancreas using reverse-transcription polymerase chain reaction （RT-PCR） and rapid amplification of cDNA ends. The full-length cDNA of CAT （2 649 bp） contains a 5＇-untranslated region （UTR） of 78 bp, a 3＇- UTR of 1 017 bp, with a poly （A） tail, and an open reading frame of 1 554 bp encoding a 517-amino-acid polypeptide with predicted molecular mass of 58.46 kDa and estimated isoelectric point of 6.64. This CAT sequence contained the proximal active site signature （60FDRERIPERWHAKGAG76）, proximal heme-ligand signature sequence （350RLFSYPDTH358） and three catalytic amino acid residues （His71, Asn144 and Tyr354）. Sequence comparison showed that the CAT deduced amino acid sequence of E. carinicauda shared 68%-92% of identities with those of other species. Quantitative real-time PCR analysis revealed that CAT mRNA was widely expressed in the hepatopancreas （highest）, hemocyte, eyestalk, heart, gill, muscle, ovary and stomach. Under low salinity stress, CAT and GPx mRNA expression levels both in the gill and hepatopancreas increased significantly at the first 48 h and 6 h respectively, indicating a tissue- and time-dependent antioxidant response in E. carinicauda. All these results indicate that E. carinicauda CAT is a member of the CAT family and might be involved in the acute response against low salinity stress.
基金supported by the National S&T Major Special Project on Major New Drug Innovation(No.2012ZX09301002-001-015)the National Natural Science Foundation of China(No.30772284)
文摘The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of H202 in nicotinamide adenine dinucleotide phosphate （NADPH） oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac 1 was dependent on the levels of intracellular H202. Puerarin blocked the phosphorylation of extracellular regulated protein kinases （ERK）1/2, abolished activator protein （AP）-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of H202-dependent Racl activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregu- lation of catalase expression and H202-dependent Racl activation.
基金the Faculty of Health Sciences,MARA University of Technology(UiTM) SelangorPuncak Alam and UiTM LESTARI grant(600-IRMI/ MYRA 5/3/LESTARI(16/2016) for the funds provided to complete this study
文摘OBJECTIVE： This study investigated the effects of allylpyrocatechol （APC）, the major component in ethanolic extract of Piper betle, on key oxidative stress resistance enzymes important for the survival of Staphylococcus aureus, a major pathogen in the human host. METHODS： Effects of APC on expressions of genes encoding catalase （katA）, superoxide dismutases （SODs）, including soda and sodM, and alkyl hydroperoxide reductase （ahpC） in S. aureus were quantitated by RT-qPCR in reference to gyrA and 16S rRNA. Corresponding activities of the enzymes were also investigated. The Livak analysis was performed for verification of gene-fold expression data. Effects of APC on intracellular and extracellular reactive oxygen species （ROS） levels were determined using the nitroblue tetrazolium （NBT） reduction assay. RESULTS： APC-treated S. aureus cells had higher sodA and sodM transcripts at 1.5-fold and 0.7-fold expressions respectively with corresponding increase in total SOD activity of 12.24 U/mL compared to untreated cells, 10.85 U/mL （P〈0.05）. Expression of ahpC was highest in APC-treated cells with 5.5-fold increased expression compared to untreated cells （P〈0.05）. Correspondingly, ahpC activity was higher in APC-treated cells at 0.672 （A310nm） compared to untreated cells which was 0.394 （A310nm）. In contrast, katA expression was 1.48-fold and 0.33-fold lower respectively relative to gyrA and 16S rRNA. Further, APC-treated cells showed decreased catalase activity of 1.8 × 10^-4 （U/L or μmol/（min.L）） compared to untreated cells, which was 4.8 × 10^-4 U/L （P〈0.05）. Absorbance readings （A575nm） for the NBT reduction assay were 0.709 and 0.695 respectively for untreated and treated cells, which indicated the presence of ROS. APC-treated S. aureus cells had lower ROS levels both extracellularly and intracellularly, but larger amounts remained intracellularly compared to extracellular levels with absorbances of 0.457 and 0.137 respectively （P〈0.05）. CONCLUSION： APC induced expressions of both sodA and sodM, resulting in increased total SOD activity in S. aureus. Higher sodA expression indicated stress induced intracellularly involving O2, presumably leading to higher intracellular pools of H2O2. A concommittant decrease in katA expression and catalase activity possibly induced ahpC expression, which was increased the highest in APC-treated cells. Our findings suggest that in the absence of catalase, cells are propelled to seek an alternatepathway involving ahpC to reduce stress invoked by O2- and H2O2. Although APC reduced levels of ROS, significant amounts eluded its antioxidative action and remained intracellularly, which adds to oxidative stress in treated cells.
基金supported by the National Pos-doctoral Foundation of China grant 20090451016Heilongjiang Province Pos-doctoral Foundation grant LRB08-485Heilongjiang Province Natural Science Foundation of grant D2007-29
文摘Objective This paper aims to assess the interaction between common variations in catalase（CAT） polymorphic gene and environmental factors for antioxidant defense enzyme in modulating individual susceptibility to colorectal cancer（CRC）.Methods A case-control study with 880 colorectal cancer cases and 848 controls was conducted to investigate whether variations in the catalase（CAT） gene,one of the genes involved in scavenging oxidative stress,influenced susceptibility to CRC.Results The interaction between life style and genotypes as well as with their effects on colorectal cancer was deduced from the present study.Significant difference（P=0.01） was identified in the distribution of CAT genotype between the colorectal cancer cases and the controls.The CRC cases had significantly lower mean activity than the controls（P〈0.01）.Correlation analyses revealed statistically significant correlations between CAT activity and CAT genotype（P〈0.01）.Conclusion The risk of CRC was associated with smoking,low vegetable consumption,high pork and poultry consumptions,and low or high BMI.This is the first study reporting an association of polymorphism CAT-21A〉T with colorectal cancer.Low CAT activity was associated with an increased risk of CRC;however,no evidence was found to support an association between CAT-21A〉T polymorphism and CRC risk.
基金Supported by the Doctoral Program Foundation of the Ministry of Education of China,No. 20060284044the Outstanding Medical Scholar Program of Jiangsu Province,No. RC2007006the Medical Science and Technology Development Program of Nanjing,No. YKK08070
文摘BACKGROUND：Mailuoning, a Chinese herb, has been widely used in China to treat acute ischemic stroke, and the major component exhibits anti-oxidative effects. However, the precise anti-oxidation pathway remains uncertain.OBJECTIVE：To validate the protective effects of Mailuoning on H202-induced primary cortical neuron injury in embryonic mice.DESIGN, TIME AND SETTING：Comparative observation and in v#ro experiments were performed at the Jiangsu Key Laboratory for Molecular Medicine from January 2008 to September 2009.MATERIALS：Mailuoning （Nanjing Jinling Medical Company, China）, reactive oxygen species （ROS） kit （Beyotime Biotechnology, China）, superoxide dismutase （SOD）, Cu/Zn SOD kit, malondialdehyde （MDA） kits （Nanjing Jiancheng, China）, mitochondrial membrane potential （GMS10013.1, GENMED, USA） and catalase activity assay kit （Beyotime Biotechnology, China） were utilized for the present study.METHODS：Mouse embryonic cortical neurons were isolated and cultured with culture medium containing H2O2 （80 μmol/L） and/or Mailuoning （1.25 μg/mL） for 24 hours.MAIN OUTCOME MEASURES：Neuronal viability and death were detected by methyl thiazolyl tetrazdium and flow cytometry; ROS production was determined by flow cytometry; mitochondriai membrane potential was detected using fluorescent staining; SOD activity was detected using a modified nitroblue tetrazolium method; Cu/Zn SOD and catalase activity was detected by spectrophotometry; and MDA was determined using the lipid peroxidation method.RESULTS：H2O2 increased ROS production and MDA concentration （P 〈 0.05）, and decreased mitochondrial membrane potential, SOD, Cu/Zn SOD and catalase activity （P 〈 0.05）; the number of surviving neurons （P 〈 0.05） was also reduced. Mai/uoning reversed these changes.CONCLUSION：Mailuoning protects H2O2-induced injury in cortical cells by inhibiting ROS and MDA, increasing depolarization of mitochondrial membrane, and enhancing SOD and catalase activity.
基金This project was supported by the National Natural Science Foundation of China (Nos. 50533030, 20374034 and 50225311) and 973 projects (No. 2003CB615700).
文摘Highly sensitive catalase electrodes for sensing hydrogen peroxide have been fabricated based on polypyrrole films with microcontainers. The microcontainers have a cup-like morphology and are arranged in a density of 4000 units cm^-2. Catalase was immobilized into the polypyrrole films with microcontainers （Ppy-mc）, which were coated on a Pt substrate electrode. The catalase/Ppy-mc/Pt electrode showed linear response to hydrogen peroxide in the range of 0-18 mmol/L at a potential of-0.3 V （versus SCE）. Its sensitivity was measured to be approximately 3.64 μA （mmol/L） ^-1 cm^- 2, which is about two times that of the electrode fabricated from a flat Ppy film （catalase/Ppy-flat/Pt electrode）. The electrode is highly selective for hydrogen peroxide and its sensitivity is interfered by potential interferents such as ascorbic acid, urea and fructose. Furthermore, such catalase electrodes showed long-term storage stability of 15 days under dry conditions at 4℃.
文摘The advantages of measuring hepatic oxidative status in liver biopsy are that it helps in diagnosis of hepatic dysfunction, reflects the degree of deterioration in the liver tissues, and helps to determine the severity of hepatic injury. We aimed to study the oxidative stress state in children with chronic hepatitis by using indirect approach in which antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) are determined in the liver tissue. The present study included 21 children and adolescents (12 males, 9 females) suffering from chronic hepatitis. Patients were selected from the Hepatology Clinic, New Children’s Hospital, Cairo University from November 2006 till 2009 and compared with a group of 7 children who happened to have incidental normal liver biopsy. Children with chronic hepatitis had mean age 8.12 ± 1.15 years. It was further subdivided into 2 subgroups: chronic viral heaptitis (n = 13) and cryptogenic hepatitis (n = 8). GPX, SOD and CAT levels were measured in fresh liver tissue (cell free homogenates) using ELISA. In chronic hepatitis group;there was a significant increase in the hepatic GPX activity (38.59 ± 35.82 nmol/min/ml) as compared to the control group (10.62 ± 6.68 nmol/min/ml). Also a significant correlation was observed between SOD and both ALT (r = 0.87, p < 0.05) and AST (r = 0.74, p < 0.05). GPX correlated with ALT (r = 0.80, p < 0.05) level in the chronic viral hepatitis subgroup. Our findings suggest that oxidative stress could play a role in the pathogenesis of chronic hepatitis. These preliminary results are encouraging to conduct more extensive clinical studies combining antioxidant therapy with various treatments.
