Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.11.1.6 (catalase)
 55,569 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have measured lipid peroxidation and the activity of antioxidant enzymes in lenses of alloxan injected rats. After 12 weeks alloxan treated rats developed lens cataract. Diabetes rats had both lower lens weight and lower level of proteins in soluble fraction of lens homogenate. Alloxan treatment is associated with a significant increase of thiobarbituric acid reactive substances and the activity of antioxidant enzymes superoxide dismutase and catalase. However, diabetes decreased the activity of glutathione peroxidase in rat lenses. These results show that alloxan, which changes antioxidant status in rat lenses, may cause complications associated with diabetes.
 ...
PMID:Alloxan induced cataract in a rat. 1181 13

The diabetogenic action of alloxan is thought to be initiated by generation of reactive oxygen species (ROS). Ascorbate can be an antioxidant in a predominantly aqueous environment, such as plasma and extracellular fluids. We have investigated the generation of ROS in the interaction of alloxan with ascorbate. Rapid oxygen consumption was observed in the reactin system of alloxan with ascorbate. The oxygen consumption was suppressed by superoxide dismutase and catalase, suggesting that superoxide and hydrogen peroxide could be generated in the reaction system. In addition, the generation of alloxan radical, an electron reductance of alloxan, and ascorbate free radical (AFR), an electron oxidant of ascorbate, was observed using electron spin resonance (ESR). Under anaerobic conditions, the ESR signal intensity of alloxan radical was significantly increased in comparison with that under aerobic conditions, whereas the intensity of AFR was significantly decreased. These results suggest that alloxan radical and AFR were generated in the reaction system of alloxan with ascorbate, and that the alloxan radical but not AFR reacted with molecular oxygen, resulting in the generation of ROS.
 ...
PMID:[Alloxan radical-induced generation of reactive oxygen species in the reaction system of alloxan with ascorbate]. 1240 Jan 64

An aqueous solution of green tea polyphenols (GTP) was found to inhibit lipid peroxidation (LP), scavenge hydroxyl and superoxide radicals in vitro. Concentration needed for 50% inhibition of superoxide, hydroxyl and LP radicals were 10, 52.5 and 136 micro g/ml, respectively. Administration of GTP (500 mg/kg b.wt.) to normal rats increased glucose tolerance significantly (P<0.005) at 60 min. GTP was also found to reduce serum glucose level in alloxan diabetic rats significantly at a dose level of 100 mg/kg b.wt. Continued daily administration (15 days) of the extract 50, 100 mg/kg b.wt. produced 29 and 44% reduction in the elevated serum glucose level produced by alloxan administration. Elevated hepatic and renal enzymes produced by alloxan were found to be reduced (P<0.001) by GTP. The serum LP levels which was increased by alloxan and was reduced by significantly (P<0.001) by the administration of 100 mg/kg b.wt. of GTP. Decreased liver glycogen, after alloxan administration showed a significant (P<0.001) increase after GTP treatment. GTP treated group showed increased antioxidant potential as seen from improvements in superoxide dismutase and glutathione levels. However catalase, LP and glutathione peroxidase levels were unchanged. These results indicate that alterations in the glucose utilizing system and oxidation status in rats increased by alloxan were partially reversed by the administration of the glutamate pyruvate transaminase.
 ...
PMID:Anti-diabetic activity of green tea polyphenols and their role in reducing oxidative stress in experimental diabetes. 1241 15

Antidiabetic and antoxidant effects of S-methyl cysteine sulfoxide (SMCS) isolated from A. cepa and two standard drugs, glibenclamide and insulin were studied and compared in alloxan diabetic rats after using each of them for treatment for two months. These drugs ameliorated the diabetic condition significantly, viz. maintenance of body weight and control of blood sugar in rats. Further they lowered the levels of malondialdehyde, hydroperoxide and conjugated dienes in tissues exhibiting antioxidant effect on lipid peroxidation in experimental diabetes. This is achieved by their stimulating effects on glucose utilization and the antioxidant enzymes, viz. superoxide dismutase and catalase. The probable mechanism of action of SMCS and glibenclamide may be partly dependent on the stimulation of insulin secretions and partly due to their individual actions. In the amelioration of diabetes the standard drugs showed a better action, but as an antioxidant SMCS proved to be a better one.
 ...
PMID:Antidiabetic and antioxidant effects of S-methyl cysteine sulfoxide isolated from onions (Allium cepa Linn) as compared to standard drugs in alloxan diabetic rats. 1258 28

Syzigium cumini commonly known as Jamun, is widely used in different parts of India for the treatment of diabetes mellitus. Oral administration of an aqueous Jamun seed extract (JSEt) for 6 weeks caused a significant decrease in lipids, thiobarbituric acid reactive substances (TBARS) and an increase in catalase and superoxide dismutase in the brain of alloxan induced diabetic rats. Oral administration of an alcoholic JSEt for 6 weeks brought back all the parameters to near normal. The effect of alcoholic JSEt (100 mg/kg) was better than aqueous JSEt (5 g/kg). The effect of both these extracts was better than glibenclamide (600 microg/kg). Thus, our study shows that S. cumini seed extracts reduce tissue damage in diabetic rat brain.
 ...
PMID:Syzigium cumini seed extracts reduce tissue damage in diabetic rat brain. 1264 17

Effects of cytotoxic agents and hydrogen peroxide were examined using pancreatic BRIN-BD11 cells and the parental insulinoma RINm5F cell line. Cell viability was determined using the MTT colorimetric assay and the TUNEL assay was used to assess apoptosis and acridine orange assay was used to determine levels of apoptosis versus necrosis. RT-PCR studies were employed to investigate the effects of the toxins on the expression of antioxidative enzymes, superoxide dismutase (SOD), glutathionine peroxidase (GPX) and catalase (CAT). Streptozotocin, hydrogen peroxide, alloxan and ninhydrin exerted time- and concentration-dependent toxic effects on BRIN-BD11 and RINm5F cells. RT-PCR showed that 90 minutes exposure of BRIN-BD11 cells or RINm5F cells to 5 mM ninhydrin down regulates SOD, GPX and CAT antioxidative enzymes. Glutathionine peroxidase gene expression was also down regulated in both types of cell by hydrogen peroxide. There were no significant differences in antioxidant gene expression after exposure to the other toxins under the conditions employed. TUNEL assay revealed that streptozotocin (8 mM) and hydrogen peroxide (125 microM) had no significant effect on the number of cells undergoing apoptosis. However after exposure to ninhydrin (5 mM) almost 100% of the non-viable BRIN-BD11 cells and around 50% of the RINm5F cells were dying by apoptosis. With the BRIN-BD11 cells there was around a 30% increase in the number of apoptotic cells compared with 50% in the RINm5F cells after exposure to alloxan (16 mM). The results indicate multiple effects of cytotoxic agents on functional integrity and antioxidant enzyme gene expression in clonal beta-cells.
 ...
PMID:Effects of cytotoxic agents on functional integrity and antioxidant enzymes in clonal beta-cells. 1268 36

The effect of sulfur dioxide (SO2) on brain antioxidant status, lipid peroxidation, and somatosensory evoked potentials (SEPs) was investigated in diabetic rats. A total of 40 rats were divided into 4 equal groups: control (C), SO2 + C (SO2), diabetic (D), and SO2 + D (DSO2). Experimental diabetes mellitus was induced by i.v. injection of alloxan at a dose of 50 mg/kg body weight. Ten ppm SO2 was administered to the rats in the sulfur dioxide groups (SO2 and DSO2) in an exposure chamber. Exposure occurred 1 hr/day, 7 days/wk, for 6 wk; control rats were exposed to filtered air during the same time periods. Although SO2 exposure markedly increased copper, zinc Superoxide dismutase activity, it significantly decreased glutathione peroxidase activity in both the diabetic and nondiabetic groups, compared with the C group. Brain catalase activity was unaltered; however, brain thiobarbituric acid reactive substances (TBARS) were elevated in all experimental groups with respect to the C group. SEP components P1, N1, P2, and N2 were significantly increased in all experimental groups, compared with the C group, and these components were also prolonged in the DSO2 group with respect to the other groups. The authors' findings suggest that exposure to SO2, because it increases lipid peroxidation, can change antioxidant enzyme activities and affect SEP components in diabetic rats.
 ...
PMID:Changes in somatosensory evoked potentials, lipid peroxidation, and antioxidant enzymes in experimental diabetes: effect of sulfur dioxide. 1274 14

Impaired homeostasis under diabetic conditions is connected with the increased production of free radicals and deficiency of antioxidative systems. The aim of this study was to analyze the effect of new oral antidiabetic drug-pioglitazone on activity of antioxidant factors and lipid peroxidation in vivo. The liver and kidney of alloxan-induced diabetic rabbits were examined after 4 and 8 weeks of treatment. After 4 weeks of diabetes the superoxide dismutase (Cu,Zn-SOD) activity in the liver was diminished while the catalase (CAT) activity and the level of ascorbic acid (AA) were elevated in comparison with the control group. Pioglitazone treatment during 4 weeks decreased the catalase activity in relation to the control diabetic animals. After 8 weeks of diabetes the CAT activity in the liver was elevated in comparison with the control group. Pioglitazone treatment during 8 weeks decreased the CAT activity and the level of lipid peroxidation products (LPO), and increased the Cu,Zn-SOD activity in relation to control diabetic animals. After 4 weeks of diabetes in the kidney the Cu,Zn-SOD activity and the level of ascorbic acid (AA) were diminished while the CAT activity and the LPO level were elevated in comparison with the control group. Pioglitazone treatment during 4 weeks increased the AA and decreased the LPO levels in relation to non-treated diabetic animals. After 8 weeks of disease the Cu,Zn-SOD activity in the kidney was diminished in comparison with the control group. Pioglitazone during 8 weeks decreased the LPO level in relation to non-treated diabetic animals. This study shows that diabetic animals undergo an important oxidative stress, which is partially corrected by pioglitazone treatment.
 ...
PMID:Effect of the new thiazolidinedione-pioglitazone on the development of oxidative stress in liver and kidney of diabetic rabbits. 1462 26

The aim of this study was to analyze the effect of the flavonoid silymarin, a free radical scavenger that prevents lipoperoxidation, on the pancreatic activity of superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and catalase (CAT) in rats with alloxan-induced diabetes mellitus. Alloxan intoxicated rats were treated with silymarin in two manners, simultaneously (four or eight doses) or 20 days after alloxan administration for 9 weeks. Alloxan elicited a transient increase in the activity of the three enzymes, which decreased after 5 days of treatment. On its own, silymarin significantly increased the activity of these enzymes. Simultaneous treatment with alloxan and silymarin also induced an increment in the activity of the enzymes followed by a delayed decrease (four doses). However, a longer treatment with silymarin (eight doses) induced a more sustained effect. Interestingly, silymarin treatment recovered to control values for the activity of the three-antioxidant enzymes that were significantly diminished after 20 days of alloxan administration. It is suggested that the protective effect of silymarin on pancreatic damage induced by alloxan may be due to an increase in the activity of antioxidant enzymes that, in addition to the glutathione system, constitute the more important defense mechanisms against damage by free radicals.
 ...
PMID:Silymarin increases antioxidant enzymes in alloxan-induced diabetes in rat pancreas. 1465 54

Oxidative stress occurs in diabetic patients and experimental models of diabetes. The ability of l-arginine to ameliorate the oxidative stress and metabolic changes after treatment with alloxan was investigated in rats. Adult male rats were injected intraperitoneally with 100 mg kg(-1) of alloxan to produce experimental oxidative stress characteristic of diabetes mellitus. Hyperglycaemia and hypercholesterolaemia were observed in serum after 7 days of alloxan treatment. This was associated with a depression of glutathione (GSH) concentration as well as superoxide dismutase (SOD) and catalase (CAT) activities in the liver and brain. In addition, the thiobarbituric acid-reactive substances (TBARS) were significantly elevated, indicating increased lipid peroxidation and oxidative stress in the same tissues. Administration of 100 mg kg(-1) l-arginine for 7 days either before or after alloxan injection significantly ameliorated the oxidative stress evidenced by a lower TBARS and a higher level of the endogenous GSH concentration and SOD and CAT activities than alloxan-treated rats. These effects were paralleled by marked protection and partial prophylaxis against alloxan-induced hyperglycaemia and cholesterolaemia. Thus, these results showed that exogenously administered l-arginine might improve the clinical manifestation of diabetes mellitus and decrease the oxidative stress in the liver and brain. In addition, the study supports the beneficial effect of l-arginine, which might be attributed to its direct, NO-dependent antioxidant capacity and/or NO-independent pathways.
 ...
PMID:L-Arginine ameliorates oxidative stress in alloxan-induced experimental diabetes mellitus. 1505 3


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>