Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: UNIPROT:P30044 (antioxidant enzyme)
8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thioredoxin reductase (TR) is a widely distributed flavoenzyme that provides reduced thioredoxin, a dithiol hydrogen donor for protein disulfide reduction and for the reduction of ribonucleotides to deoxyribonucleotides, the first unique step of DNA synthesis. Antitumor quinones were found to exhibit time- and concentration-dependent inhibition of purified rat liver TR that requires the presence of NADPH. Diaziquone initially shows competitive inhibition of the enzyme with 5,5'-dithiobis 2-nitrobenzoic acid as substrate with a Ki of 7.5 microM, which becomes non-competitive after 1 hour incubation with NADPH with a Ki of 0.5 microM. Doxorubicin shows non-competitive inhibition both initially and after 1 hr incubation with NADPH, with Ki values of 10 microM and 0.5 microM, respectively. Electron spin resonance spectroscopy showed the formation of semiquinone free radicals by TR incubated under anaerobic conditions with doxorubicin or diaziquone and NADPH. Redox cycling and formation of oxygen radicals does not play a major role in the inhibition of TR by antitumor quinones as shown by the minor effect on inhibition of removing O2, and the lack of effect of superoxide dismutase and catalase. Diaziquone causes time- and concentration-dependent inhibition of TR activity in intact A204 human rhabdomyosarcoma cells that is associated with growth inhibition. The results suggest that inhibition of TR by antitumor quinones could contribute to their growth inhibitory properties.
...
PMID:Inhibition of thioredoxin reductase (E.C. 1.6.4.5.) by antitumor quinones. 216 13

Doxorubicin and mitoxantrone were given to mice in a single dose of 15 mg/kg body wt (i.p.) and lipid peroxidation assays were carried out 3, 4 and 5 days after injection. Four days after injection, mitoxantrone induced an increase of 155% in liver spontaneous chemiluminescence and increases of 73% and 52% in malonaldehyde levels and hydroperoxide-initiated chemiluminescence of liver homogenates. Three days after injection, administration of doxorubicin produced increases of 51% and 53% in liver spontaneous chemiluminescence and malonaldehyde formation respectively, but no changes in hydroperoxide-initiated chemiluminescence of liver homogenates were observed. The hepatic levels of antioxidant enzymes were measured in mice treated with doxorubicin or mitoxantrone. Administration of mitoxantrone caused decreases of 50%, 27% and 42% in Cu-Zn superoxide dismutase, catalase and glutathione peroxidase activities, respectively. Doxorubicin also induced decreases in antioxidant enzyme levels but the effect was less marked. Our studies suggest that mitoxantrone might be more hepatotoxic than doxorubicin and that the mechanism of its toxicity would involve a reduction in antioxidant defenses.
...
PMID:Hepatotoxicity of mitoxantrone and doxorubicin. 239 34

The purpose of this study was to correlate the exercise-induced changes of oxidant stress enzymes with possible modification of the response to the putative oxidant stressor doxorubicin. Enzymatic and histological changes were studied in mice placed on a 21-wk swim training program (1 h/day, 5 days/wk) with and without anthracycline administration. Doxorubicin (4 mg/kg) was administered intravenously through a tail vein on 10 separate days over a 7-wk period (twice weekly during weeks 10, 11, 14, 15, and 16). Blood, liver, and heart levels of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GP) were measured following the 9th and 21st wk. Myocardial histomorphological observations were made by light microscopy after 21 wk. Following 9 wk of training swim-trained animals had significantly elevated levels of CAT, SOD, and GP in blood, as well as elevated GP in liver. After 21 wk, trained animals, regardless of drug status, had elevated blood CAT and SOD activity and increased liver CAT and GP. Training also produced increases in blood GP, liver SOD, and heart CAT; however, in conjunction with doxorubicin these changes were not seen. The degree of cardiotoxicity was significantly greater in the sedentary drug-treated animals than in the swim-trained drug-treated animals. The results suggest a correlation between antioxidant enzyme levels in blood and liver and the degree of damage caused by an anthracycline drug. It was concluded that exercise ameliorates severe toxic damage caused by doxorubicin administration, possibly by increasing enzymes that combat free radical damage.
...
PMID:Effect of exercise training on antioxidant enzymes and cardiotoxicity of doxorubicin. 405 7

Adriblastin was shown to activate considerably lipid peroxidation processes in the heart muscle, mostly through the suppression of antioxidant enzyme (superoxidedysmutase and catalase) activity, with myocardial contractility declining essentially as a result. Pretreatment with the synthetic antioxidant ionol prevented the adriblastin-induced depression of myocardial contractility.
...
PMID:[Prevention of disorders of the contractile function of the heart after chemical induction of lipid peroxides]. 409 16

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3), the hormonal form of vitamin D, has anticancer activity in vivo and in vitro. Doxorubicin exerts its cytotoxic effect on tumor cells mainly by two mechanisms: (a) generation of reactive oxygen species (ROS); and (b) inhibition of topoisomerase II. We studied the combined cytotoxic action of 1,25(OH)2D3 and doxorubicin on MCF-7 breast cancer cells. Pretreatement with 1,25(OH)2D3 resulted in enhanced cytotoxicity of doxorubicin. The average enhancing effect after a 72-h pretreatment with 1,25(OH)2D3 (10 nM) followed by a 24-h treatment with 1 microg/ml doxorubicin was 74+/-9% (mean +/- SE). Under these experimental conditions, 1,25(OH)2D3 on its own did not affect cell number or viability. 1,25(OH)2D3 also enhanced the cytotoxic activity of another ROS generating quinone, menadione, but did not affect cytotoxicity induced by the topoisomerase inhibitor etoposide. The antioxidant N-acetylcysteine slightly reduced the cytotoxic activity of doxorubicin but had a marked protective effect against the combined action of 1,25(OH)2D3 and doxorubicin. These results indicate that ROS are involved in the interaction between 1,25(OH)2D3 and doxorubicin. 1,25(OH)2D3 also increased doxorubicin cytotoxicity in primary cultures of rat cardiomyocytes. Treatment of MCF-7 cells with 1,25(OH)2D3 alone markedly reduced the activity, protein, and mRNA levels of the cytoplasmic antioxidant enzyme Cu/Zn superoxide dismutase, which indicated that the hormone inhibits its biosynthesis. This reduction in the antioxidant capacity of the cells could account for the synergistic interaction between 1,25(OH)2D3 and doxorubicin and may also suggest increased efficacy of 1,25(OH)2D3 or its analogues in combination with other ROS-generating anticancer therapeutic modalities.
...
PMID:1,25-Dihydroxyvitamin D3 enhances the susceptibility of breast cancer cells to doxorubicin-induced oxidative damage. 1002 76

Doxorubicin continues to be one of the most widely used anticancer agents in the clinic despite its dose-limiting side-effects. Many of doxorubicin's dose-limiting toxicities occur due to its generation of toxic oxygen species, resulting in oxidative stress. Some clinical observations have suggested that doxorubicin may have greater toxicity in older patients. The studies presented here compare basal and doxorubicin-induced antioxidant enzyme activities in brain, heart, kidney and liver tissues of Fisher 344 rats of different ages to determine whether differences in these enzymes can account for the age-dependent differences observed in doxorubicin-induced toxicity. Three groups of animals were tested, young animals (2-months-old), adult animals (10-months-old) and old animals (18-months-old). The results of these studies show that in general young and adult animals have similar levels of antioxidant enzyme activity while the older animals have less. Only in the young animals is antioxidant enzyme activity significantly increased following doxorubicin treatment suggesting that enzyme induction occurs only in the young group of animals. Lipid peroxidation is shown to have the greatest increase in the old animals following doxorubicin treatment while the young animals have the smallest increase. The results from these studies suggest that there is an increase in doxorubicin-induced oxidative damage with age and that these differences may be due to basal and drug-induced differences in tissue antioxidant enzyme activities.
...
PMID:Basal and drug-induced antioxidant enzyme activities correlate with age-dependent doxorubicin oxidative toxicity. 1090 15

Doxorubicin (Dox) is a highly effective antineoplastic antibiotic associated with a dose-limiting cardiotoxicity that may result in irreversible cardiomyopathy and heart failure. The purpose of this study was to examine the effects of low-intensity exercise training (LIET) during the course of Dox treatment on cardiac function, myosin heavy chain expression, oxidative stress, and apoptosis activation following treatment. Male Sprague-Dawley rats either remained sedentary or were exercise trained on a motorized treadmill at 15 m/min, 20 min/day, 5 days/wk (Monday through Friday) for 2 wk. During the same 2-wk period, Dox (2.5 mg/kg) or saline was administered intraperitoneally to sedentary and exercised rats 3 days/wk (Monday, Wednesday, Friday) 1-2 h following the exercise training sessions (cumulative Dox dose: 15 mg/kg). Five days following the final injections, hearts were isolated for determination of left ventricular (LV) function, lipid peroxidation, antioxidant enzyme protein expression, 72-kDa heat shock protein expression, caspase-3 activity, and myosin heavy chain isoform expression. Dox treatment significantly impaired LV function and increased caspase-3 activity in sedentary animals (P < 0.05). LIET attenuated the LV dysfunction and apoptotic signal activation induced by Dox treatment and increased glutathione peroxidase expression, but it had no significant effect on lipid peroxidation, protein expression of myosin heavy chain isoforms, 72-kDa heat shock protein, or superoxide dismutase isoforms. In conclusion, our data suggest that LIET applied during chronic Dox treatment protects against cardiac dysfunction following treatment, possibly by enhancing antioxidant defenses and inhibiting apoptosis.
...
PMID:Low-intensity exercise training during doxorubicin treatment protects against cardiotoxicity. 1621 Apr 42

Clinical use of doxorubicin continues to be challenged by its undesirable systematic toxicity, caused mainly by oxidative stress. The aim of this study was to investigate the effectiveness of fullerenol C(60)(OH)(24) polyanion nanoparticles, an antioxidant agent, against doxorubicin-induced nephro-, testicular, and pulmonary toxicity. Results obtained in vitro suggest that fullerenol's anti-proliferative property and protective effect against doxorubicin cytotoxicity are mediated by the antioxidative and radical scavenging activity. Male Wistar rats were divided into five treatment groups: the control group (I) received 0.9% NaCl (1 mL/kg, i.p.). Groups II, III, IV, and V received a single dose of doxorubicin (10 mg/kg i.p.), doxorubicin/fullerenol (100 and 50 mg/kg i.p. of fullerenol 30 min prior to 10 mg/kg i.p. of doxorubicin), and fullerenol (100 mg/kg i.p.), respectively. On the 2(nd) and 14(th) days, organ samples were taken for the measurement of lipid peroxidation and activities of superoxide dismutase, catalase, glutathione-peroxidase, -reductase, and -transferase. Doxorubicin induced a significant increase of lipid peroxidation and alterations of antioxidant enzyme activities, while the fullerenol pre-treatment prevented the effects of doxorubicin on investigated parameters. Fullerenol, applied alone, did not alter basal values of the investigated animals. Considering the mechanisms of doxorubicin toxicity, it can be concluded that fullerenol exerts its protective role by acting as a free radical sponge and/or by removing free iron through formation of fullerenol-iron complex. Results of this study support the hypothesis of testicular, pulmo-, and nephroprotective efficacy of fullerenol in preventing oxidative stress induced by doxorubicin.
...
PMID:Antioxidant properties of fullerenol C60(OH)24 in rat kidneys, testes, and lungs treated with doxorubicin. 2049 20

Doxorubicin (DXR), a highly effective chemotherapeutic agent, causes serious injury when extravasated. The injury can sometimes result in skin necrosis and ulceration, requiring surgery. The detrimental effect of DXR on the antioxidant system via free oxygen radicals is one of the mechanisms proposed in its etiology. Thus, we used melatonin, a potent antioxidant, and compared the effects with dimethylsulfoxide (DMSO), which is used in the treatment of patients with DXR-induced extravasation.Twenty-seven Wistar-albino rats were used. After intradermal injection of DXR, DMSO was injected into the extravasated area and melatonin was given intraperitoneally. On day 14 of the experiment, skin ulcers were clearly formed and samples were taken with a punch biopsy. Ulcer sizes were measured. Tissue samples were analyzed for superoxide dismutase, glutathione peroxidase, and malondialdehyde enzymes, and histopathologically evaluated.Melatonin clearly decreased MDA levels, ulcer size, and histopathologic ulcer scores in DXR extravasated tissue. DMSO also decreased MDA levels, ulcer size and histopathologic ulcer score. However, melatonin was remarkably more effective than DMSO in terms of antioxidant enzyme activity, oxidative stress, and histopathologic ulcer scores in rats. Necrosis was evident in the DXR-treated group and some slides showed necrosis involving the fascia. Histopathologic ulcer scores of the necrotic tissue decreased in the DMSO and melatonin groups. The ulcer score in the melatonin group was significantly lower than in the control group. Although the ulcer score in the DMSO group was lower than control, there was no statistically significant difference. The ulcer size in the DMSO group was significantly lower than the control group. The ulcer size in the melatonin group was significantly lower than both the DMSO and control groups.We believe that melatonin, either alone or in combination with DMSO, may be used for treating DXR extravasation. In addition, free oxygen radicals play a crucial role in the etiology of the injury, which should be considered in further studies.
...
PMID:Melatonin ameliorates doxorubicin-induced skin necrosis in rats. 2096 55

Doxorubicin (DOX) is one of the most powerful and widely prescribed chemotherapeutic agents to treat divergent human cancers. However, the clinical use of DOX is restricted due to its severe cardiotoxic side-effects. There has been ongoing search for cardioprotectants against DOX toxicity. Inorganic nitrate has emerged as a bioactive compound that can be reduced into nitrite and nitric oxide in vivo and in turn plays a therapeutic role in diseases associated with nitric oxide insufficiency or dysregulation. In this review, we describe a novel concept of using dietary supplementation of inorganic nitrate to reduce DOX-induced cardiac cellular damage and dysfunction, based on our recent promising studies in a mouse model of DOX cardiotoxicity. Our data show that chronic oral ingestion of sodium nitrate, at a dose equivalent to ~400% of the Acceptable Daily Intake of the World Health Organization, alleviated DOX-induced left ventricular dysfunction and mitochondrial respiratory chain damage. Such cardioprotective effects were associated with reduction of cardiomyocyte necrosis/apoptosis, tissue lipid peroxidation, and mitochondrial H(2)O(2) generation following DOX treatment. Furthermore, proteomic studies revealed enhanced cardiac expression of mitochondrial antioxidant enzyme - peroxiredoxin 5 in the nitrate-treated animals. These studies suggest that inorganic nitrate could be an inexpensive therapeutic agent for long-term oral administration in preventing DOX-induced cardiac toxicity and myopathy during the prolonged pathological process. Future clinical trials in the cancer patients undergoing DOX chemotherapy are warranted to translate these experimental findings into an effective new therapy in preventing the DOX-induced cardiomyopathy.
...
PMID:Dietary inorganic nitrate alleviates doxorubicin cardiotoxicity: mechanisms and implications. 2248 29


1 2 3 Next >>

---