We studied the overproduction of catalase (CAT) by Bacillus sp.WSHDZ-01 by oxidative stress via the feeding of ethanol and the pulse addition of H2O2. By adding 2.0% (V/V) ethanol to the culture broth, the intracellular CAT activity reached 11 151 U/mL, which was 2.5 times than that of the control (4 450 U/mL in flask). By adding 0.3% (V/V) H2O2, more extracellular CAT secreted to the culture broth, and the ratio of extracellular CAT to the total CAT increased to 27%. Based on these results, an oxidative stress strategy combining the ethanol feeding and the pulse addition of H2O2 was developed. With this strategy, the ratio of extracellular CAT to the total CAT reached 82.5%, increased by 18.6% than that of the control (without ethanol and H2O2 addition). CAT production increased to 28 990 U/mL, which was 95.5% higher than the control (14 830 U/mL in 3 L fermentor). The fermentation time decreased to 42 h, which was much shorter than that of adding ethanol or H2O2, and CAT productivity reached 470 U/(mL x h) while the control achieved 396.4 U/(mL x h).
Bacillus subtilis ; drug effects ; enzymology ; physiology ; Catalase ; biosynthesis ; Culture Media ; pharmacology ; Ethanol ; pharmacology ; Hydrogen Peroxide ; pharmacology ; Oxidative Stress

OBJECTIVETo explore the effects and mechanisms of ascorbic acid (AA) and sodium selenite (SS) on growth inhibition and redifferentiation in human gastric cancer cells.

METHODSIn the present study, trypan blue dye exclusion method was used to determine the cell growth curve and mitotic index, cell electrophoresis and colonogenic potential were used as the indexes of redifferentiation. In order to find out the mechanisms of redifferentiation, the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were assayed, the content of malondialdehyde (MDA), reduced glutathione (GSH) and H2O2 were evaluated.

RESULTSAfter treatment with AA 3 mol/L + SS 2 mu mol/L, the growth rate and mitotic index of human gastric cancer cells (MGc-803) decreased remarkably. The indexes related with cell malignancy were alleviated. For example, cell surface charge was obviously decreased, the electrophoresis rate was dropped from 2.21 to 1.15 mu m.s-1.V-1.cm-1. The indexes related with cell redifferentiation were promoted. For example, the colonogenic potential was decreased to 93.5%. These results indicated that redifferentiation of human gastric cancer cells was successfully induced by AA + SS. The activities of SOD and GPX were significantly higher, while the activity of CAT was slower in treated group than that in the control. The content of MDA was slightly decreased, GSH was sharply decreased, and H2O2 content was dramatically increased.

CONCLUSIONThese results indicated that combination of ascorbic acid and sodium selenite may induce the redifferentiation of human gastric cancer cells and inhibit cell growth by virtue of enhancing the activities of antioxidative enzymes and inducing the formation of H2O2, and altering the cell redox status. Combination of ascorbic acid and sodium selenite may be a potent anticancer agent for human gastric cancer.

Antioxidants ; pharmacology ; Ascorbic Acid ; pharmacology ; Catalase ; pharmacology ; Cell Differentiation ; Glutathione Peroxidase ; pharmacology ; Humans ; Mitotic Index ; Sodium Selenite ; pharmacology ; Stomach Neoplasms ; pathology ; Superoxide Dismutase ; pharmacology ; Tumor Cells, Cultured

The well-known detrimental effects of cadmium (Cd) on plants are chloroplast destruction, photosynthetic pigment inhibition, imbalance of essential plant nutrients, and membrane damage. Jasmonic acid (JA) is an alleviator against different stresses such as salinity and drought. However, the functional attributes of JA in plants such as the interactive effects of JA application and Cd on rapeseed in response to heavy metal stress remain unclear. JA at 50 µmol/L was observed in literature to have senescence effects in plants. In the present study, 25 µmol/L JA is observed to be a "stress ameliorating molecule" by improving the tolerance of rapeseed plants to Cd toxicity. JA reduces the Cd uptake in the leaves, thereby reducing membrane damage and malondialdehyde content and increasing the essential nutrient uptake. Furthermore, JA shields the chloroplast against the damaging effects of Cd, thereby increasing gas exchange and photosynthetic pigments. Moreover, JA modulates the antioxidant enzyme activity to strengthen the internal defense system. Our results demonstrate the function of JA in alleviating Cd toxicity and its underlying mechanism. Moreover, JA attenuates the damage of Cd to plants. This study enriches our knowledge regarding the use of and protection provided by JA in Cd stress.
Brassica napus/metabolism* ; Cadmium/toxicity* ; Catalase/metabolism* ; Cyclopentanes/pharmacology* ; Oxylipins/pharmacology* ; Photosynthesis ; Plant Leaves/metabolism* ; Superoxide Dismutase/metabolism*

The effect of antioxidants on the in vitro life span of mouse keratinocytes was investigated in this work. It was found that the life span of the keratinocytes cultured in the medium supplemented with antioxidants was extended significantly. The most beneficial antioxidant used in this work was the mercaptoethanol, followed by the catalase and SOD. However, the growth rates of keratinocytes in vitro under all the experimental conditions still declined with the culture time. It was also found that the antioxidants added in the medium were also helpful to enhance the keratinocyte colony formation. In addition, the aging kinetics of the mouse epidermal keratinocytes in vitro were analyzed, and finally the aging rate constants corresponding to antioxidants used were calculated.
Animals ; Antioxidants ; pharmacology ; Catalase ; pharmacology ; Cell Division ; drug effects ; Cells, Cultured ; Cellular Senescence ; drug effects ; Keratinocytes ; cytology ; drug effects ; Mercaptoethanol ; pharmacology ; Mice ; Superoxide Dismutase ; pharmacology

Crude elicitor of one endophytic fungi (belong to Cunninghamella sp., named AL4) induced multiple responses in Atractylodes lancea suspension cells, including rapid generation of nitric oxide (NO) and hydrogen peroxide (H2O2), sequentially followed by enhancement of essential oil production. Adding NO-specific scavenger 2-4-carboxyphenyl-4,4,5, 5-tetramethylimidazol ine-1-oxyl-3-oxide (cPTIO) and H2O2 scavenger catalase (CAT) could block elicitor-induced NO and H2O2 generation respectively, but could all partly block elicitor-induced essential oil biosynthesis. Adding NO-donor sodium nitroprusside (SNP) and H2O2 could all promote essential oil accumulation in A. lancea cells, but the effect of both was different. These results strongly suggested that NO and H2O2 may all act as signaling molecule to mediate AL4 elicitor promoting essential oil accumulation in suspension cells of A. lancea. Furthermore, adding cPTIO and CAT contemporarily could not completely inhibit essential oil accumulation induced by AL4 elicitor. This result suggested that AL4 elicitor could also promote essential oil accumulation in suspension cells of A. lancea by other means.
Atractylodes ; cytology ; metabolism ; Benzoates ; pharmacology ; Catalase ; pharmacology ; Cells, Cultured ; Cunninghamella ; physiology ; Hydrogen Peroxide ; metabolism ; Imidazoles ; pharmacology ; Nitric Oxide ; metabolism ; Oils, Volatile ; analysis ; metabolism

Reactive oxygen species such as superoxides, hydrogen peroxide (H2O2) and hydroxyl radicals have been suggested to be involved in the catalytic action of nitric oxide synthase (NOS) to produce NO from L-arginine. An examination was conducted on the effects of oxygen radical scavengers and oxygen radical-generating systems on the activity of neuronal NOS and guanylate cyclase (GC) in rat brains and NOS from the activated murine macrophage cell line J774. Catalase and superoxide dismutase (SOD) showed no significant effects on NOS or GC activity. Nitroblue tetrazolium (NBT, known as a superoxide radical scavenger) and peroxidase (POD) inhibited NOS, but their inhibitory actions were removed by increasing the concentration of arginine or NADPH respectively, in the reaction mixture. NOS and NO-dependent GC were inactivated by ascorbate/FeSO4 (a metal-catalyzed oxidation system), 2'2'-azobis-amidinopropane (a peroxy radical producer), and xanthine/xanthine oxidase (a superoxide generating system). The effects of oxygen radicals or antioxidants on the two isoforms of NOS were almost similar. However, H2O2 activated GC in a dose-dependent manner from 100 microM to 1 mM without significant effects on NOS. H2O2-induced GC activation was blocked by catalase. These results suggested that oxygen radicals inhibited NOS and GC, but H2O2 could activate GC directly.
Animal ; Antioxidants/pharmacology ; Brain/enzymology ; Catalase/pharmacology ; Cell Line ; Guanylate Cyclase/metabolism* ; Hydrogen Peroxide/pharmacology ; Macrophages/enzymology ; NADP/pharmacology ; Nitric-Oxide Synthase/metabolism* ; Nitroblue Tetrazolium/pharmacology ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species/metabolism* ; Signal Transduction ; Superoxide Dismutase/pharmacology

OBJECTIVETo investigate whether cadmium-induced oxidative stress in the kidney is influenced by zinc and selenium.

METHODSFive groups of rats were maintained: (A) Cd (CdCl2, 400 micrograms.kg-1.day-1 intraperitoneal injection); (B) Cd + Zn (ZnCl2, 20 mg.kg-1.day-1 hypodermic injection); (C) Cd + Se (Na2SeO3, 350 micrograms.kg-1.day-1 via a stomach tube); (D) Cd + Zn + Se; (E) treated with physiological saline as a sham-handled control. The rats were given treatment for a period of 4 weeks. The activities of superoxide dismutase (SOD), glutathione peroxidase (GH-Px), catalase (CAT), and the level of malondialdehyde (MDA) in the kidney tissue were measured to assess the oxidative stress. Urinary lactate dehydrogenase (LDH) activity was used as an indicator of tubular cell damage caused by lipid peroxidation.

RESULTSIn group C and D, activities of SOD (110.5 +/- 5.2, 126.8 +/- 7.0; P < 0.05) and GSH-Px (85.7 +/- 4.9, 94.6 +/- 7.3; P < 0.05) were higher than those in group A (84.7 +/- 3.3; 56.9 +/- 3.8); and in group B, only the activity of GSH-Px (80.0 +/- 4.3, P < 0.01) increased in comparison with that in group A (56.9 +/- 3.8). Significant increase of MDA (P < 0.05) was seen in group B (31.1 +/- 4.7) and C (35.0 +/- 4.1) when compared with control values (17.2 +/- 1.8). No difference was found in the level of MDA between group D (18.9 +/- 2.6) and control. The activity of LDH in urine of control group (0.06 +/- 0.02) was lower than that of group A (0.46 +/- 0.19, P < 0.05), B (0.10 +/- 0.05, P < 0.05) and C (0.14 +/- 0.07, P < 0.05), and there was no significant change between control (0.06 +/- 0.02) and group D (0.08 +/- 0.02).

CONCLUSIONZinc or selenium could partially alleviate the oxidative stress induced by cadmium in kidney, but administration cadmium in combination with zinc and selenium efficiently protects kidney from cadmium-induced oxidative damage.

Animals ; Cadmium ; adverse effects ; Catalase ; pharmacology ; Drug Interactions ; Glutathione Peroxidase ; pharmacology ; Kidney ; drug effects ; pathology ; L-Lactate Dehydrogenase ; pharmacology ; Male ; Oxidative Stress ; Rats ; Rats, Wistar ; Selenium ; pharmacology ; Superoxide Dismutase ; pharmacology ; Zinc ; pharmacology

The loss of retinal pigment epithelium (RPE) with aging is related to age-related macular degeneration (AMD). This study was conducted to investigate the mechanism of hydrogen peroxide (H2O2) induced cell death in a human retinal pigment epithelial cell line, ARPE-19. Hydrogen peroxide was added at different concentrations to ARPE-19 cells and cultured. The cytotoxicity was assayed by mitochondrial function using 3- (4, 5-dimethylthiazol-2-yl) -2, 5-diphenyl tetrazolium bromide (MTT) testing. The patterns of cell damage were assessed using an acridine orange-ethidium bromide differential staining method, in situ end labeling (ISEL) assay and transmission electron microscopy (TEM). Catalase, a major antioxidant, was used to prevent cell death. The cleavage of procaspase 3 and poly (ADP-ribose) polymerase (PARP) was determined by western blot analysis. Hydrogen peroxide significantly induced cell death in ARPE-19 cells, whereas pretreatment of the cells with catalase prevented cell death. Application of the ISEL assay and acridine orange/ethidium bromide staining demonstrated that the H2O2-induced cell death occurred by an apoptotic mechanism at lower concentrations of H2O2 (400, 500, 600 microM), whereas higher concentrations of H2O2 induced necrosis rather than apoptosis. Caspase 3 was associated with the apoptotic pathway in human RPE cell death. Western blot analysis confirmed caspase 3 activation and cleavage of substrate proteins in ARPE-19 cells treated with an H2O2 concentration of 600 microM. These results indicate that treatment with H2O2 induces apoptotic and necrotic cell death in ARPE-19, and that caspase 3 is associated with apoptotic cell death. Therefore, H2O2 may induce the destruction of RPE cells in AMD by the combined effects of apoptosis and necrosis.
Apoptosis ; Caspases/metabolism ; Catalase/pharmacology ; Cell Line ; Cell Survival/drug effects ; Enzyme Activation ; Human ; Hydrogen Peroxide/*pharmacology ; Necrosis ; Pigment Epithelium of Eye/*drug effects/enzymology/pathology/*physiology

The effectiveness of several sulfhydryl compounds in the treatment of paraquat intoxication has been previously tested based on their antioxidant ability. However, practical guidelines for their clinical use remain to be determined. As a preliminary pharmacokinetic study on sulfhydryl compounds, we attempted to establish the optimal concentration of N-acetyl-L-cysteine, glutathione, superoxide dismutase, and catalase. We measured the antioxidant effect of these antioxidants in normal pooled plasma and on intracellular reactive oxygen species (ROS) induced by paraquat. N-acetyl-L-cysteine begins to suppress the production of ROS in plasma at concentrations as low as 5 mM, with the suppression being maximal at 40 mM. In the same way, glutathione increased the total antioxidant status in plasma at concentrations of 5-40 mM in a dose-dependent manner. Complete suppression of ROS in plasma induced by exposure to 500 micrometer paraquat for 40 min was observed when using 40 mM N-acetyl-L-cysteine and 5 mM glutathione. These concentrations are comparable with 50 units of catalase, which reduced ROS at concentrations of 5-100 units. Further pharmacokinetic study into the systemic administration of these antioxidants is necessary, using effective concentrations of 5-40 mM for both N-acetyl-L-cysteine and glutathione, and 1-50 units of catalase.
Acetylcysteine/*pharmacology ; Animals ; Antioxidants/pharmacokinetics/*pharmacology ; Ascorbic Acid/metabolism ; Catalase/metabolism ; Dose-Response Relationship, Drug ; Free Radical Scavengers/pharmacology ; Glutathione/metabolism/*pharmacology ; Human ; Mice ; NIH 3T3 Cells ; Paraquat/pharmacology ; Reactive Oxygen Species ; Serum/*drug effects ; Support, Non-U.S. Gov't

OBJECTIVETo study the abnormal reactions of a series of free radicals and the oxidative damages induced by free radical abnormal reactions in the bodies of patients with chronic glomerulonephritis.

METHODSEighty chronic glomerulonephritis patients (CGNP) and eighty healthy adult volunteers (HAV) were enrolled in a random control study, in which concentrations of nitric oxide (NO) in plasma, lipoperoxides (LPO) in plasma and in erythrocytes, and vitamin C (VC), vitamin E (VE) and beta-carotene (beta-CAR) in plasma as well as activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in erythrocytes were determined with spectrophotometric assays.

RESULTSCompared with the average values of the above biochemical parameters in the HAV group, the average values of NO in plasma, and LPO in plasma and erythrocytes in the CGNP group were significantly increased (P = 0.0001), while those of VC, VE and beta-CAR in plasma as well as those of SOD, CAT and GPX in erythrocytes in the CGNP group were significantly decreased (P = 0.0001). Pearson product-moment correlation analysis showed that with increase of the concentration of blood creatinine as well as prolongation of the course of disease in the CGNP, the concentrations of NO in plasma, and LPO in plasma and erythrocytes in the CGNP increased gradually, while the concentrations of VC, VE and beta-CAR in plasma as well as the activities of SOD, CAT and GPX in erythrocytes in the CGNP decreased gradually (P = 0.002454-0.000001). The relative risk ratio (RR) of the above biochemical parameters reflecting oxidative damages in the bodies of CGNP ranged from 6.061 to 72.429. The reliability coefficient (alpha) that the above biochemical parameters were used to reflect the oxidative damages of the CGNP was 0.8137, standardized item alpha = 0.9728, Hotelling's T-Squared = 1135680.191, F = 53274.6478, P = 0.000001.

CONCLUSIONSThe findings in this study show that in the bodies of CGNP a series of free radical chain reactions result in severe pathological aggravation and induce oxidative damages in their bodies. Therefore, suitable dose of antioxidants should be supplemented to them so as to alleviate oxidative damages in their bodies.

Adult ; Antioxidants ; pharmacology ; therapeutic use ; Catalase ; pharmacology ; Chronic Disease ; Erythrocytes ; enzymology ; Female ; Free Radicals ; adverse effects ; Glomerulonephritis ; physiopathology ; Glutathione Peroxidase ; pharmacology ; Humans ; Lipid Peroxidation ; Male ; Nitric Oxide ; adverse effects ; analysis ; Oxidation-Reduction ; Oxidative Stress ; Superoxide Dismutase ; pharmacology