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Plasma oxidants and antioxidants in acute ischaemic stroke.

Plasma levels of the oxidants xanthine oxidase, nitric oxide and malondialdehyde and the antioxidants superoxide dismutase, glutathione peroxidase and glutathione reductase, together with total superoxide scavenger activity and non-enzymatic superoxide scavenger activity, were determined in 19 patients with acute ischaemic stroke and 20 controls. Compared with controls, superoxide dismutase, total superoxide scavenger activity, glutathione peroxidase and glutathione reductase activities were significantly lower, and nitric oxide and malondialdehyde levels significantly higher, in acute stroke patients. Xanthine oxidase showed a slight but non-significant increase in stroke patients compared with controls. There was no significant difference in non-enzymatic superoxide scavenger activity between the two groups. There was a positive correlation between glutathione reductase levels and Glasgow Coma Scale scores, and a negative correlation between malondialdehyde levels and non-enzymatic superoxide scavenger activity. These findings suggest that oxidative stress in patients with acute ischaemic stroke may be the result of an imbalance in oxidant/antioxidant homeostasis.

Antioxidants↗
PubMed2007

Black grape and garlic extracts protect against cyclosporine a nephrotoxicity.

The aim of this study was to determine if the natural antioxidant foods, dried black grape and garlic, protect against cyclosporine nephrotoxicity. Forty-two Sprague-Dawley rats were given Cyclosporine A (CsA) orally for 10 days, with the antioxidant food supplementation begun 3 days before CsA treatment and continued during the study period (totaling 13 days). In each group (control, CsA alone, CsA plus black grape, CsA plus aqueous garlic extract, aqueous garlic extract alone and black grape alone), there were 7 animals. At the end of the study period, the animals were sacrificed; their kidneys were removed and prepared for biochemical and histopathological investigations. Oxidant (xanthine oxidase enzyme and malondialdehyde) and antioxidant (superoxide dismutase, glutathione peroxidase and catalase enzymes) parameters were measured in the kidney tissues of the groups. Histopathological examinations of the tissues were also performed. It has been found that CsA creates oxidant load to the kidneys through both xanthine oxidase activation and impaired antioxidant defense system, which accelerates oxidation reactions in the kidney tissue. Supplementation with either dried black grape or aqueous garlic extract led to reduced malondialdehyde level in the kidney tissue possibly, by preventing oxidant reactions. In conclusion, the results suggest that impaired oxidant/antioxidant balance may play part in the CsA-induced nephrotoxicity, and some foods with high antioxidant power may ameliorate this toxicity, in agreement with studies with antioxidant vitamins.

Animals↗
PubMed1993

A carrageenan hydrogel stabilized colloidal gold multi-enzyme biosensor electrode utilizing immobilized horseradish peroxidase and cholesterol oxidase/cholesterol esterase to detect cholesterol in serum and whole blood.

The preparation of two immobilized enzyme electrodes is described. One electrode contains horseradish peroxidase absorbed to colloidal gold and deposited on a glassy carbon electrode along with cholesterol oxidase entrapped in a carrageenan hydrogel. The second electrode also includes cholesterol esterase entrapped in the carrageenan. The incorporation of ferrocene or ferrocenecarboxylic acid mediator is brought about by either evaporation on the glassy carbon electrode or, in the latter case, entrapment in the carrageenan hydrogel. Amperometric signal generation results from the HRP catalyzed turnover of H2O2, a secondary product of the cholesterol oxidase catalyzed oxidation of cholesterol. Use of these enzyme electrodes makes cholesterol detection possible in human serum, low density lipoprotein, and whole blood.

Biosensing Techniques↗
PubMed2005

Antiinflammatory effects of chiisanoside and chiisanogenin obtained from the leaves of Acanthopanax chiisanensis in the carrageenan- and Freund's complete adjuvant-induced rats.

To find the antiinflammtory constituents of Acanthopanax chiisanensis (Araliaceae) leaves, phytochemical isolation procedures were performed by activity-guided fractionation in carrageenan- and Freund's complete adjuvant (FCA) reagent-induced rat models, respectively. In the two assay system, the MeOH extract (100 and 250 mg/kg, p.o.) showed significant antiinflammtory effects. Since BuOH extract among the fractionated extracts exhibited the most potent effect, it was subjected to column chromatography to yield a main triterpene glycoside, chiisanoside (1). This compound was hydrolyzed in alkaline solution to find the biological activity of produced aglycone, chiisanogenin (1a). Oral treatment with compounds 1 and 1a produced significant antiinflammtory effects at 10 and 30 mg/kg dose, and 1a was more potent than 1. The antiiflammtory effects of the two compounds were supported by the reduction of carrageenan-induced lipid peroxidation and hydroxy radical in serum. Furthermore, treatment with 1 and 1a significantly reduced rheumatoid arthritis (RA) and C-reactive protein (CRP) factors in the rat induced by Freund's complete adjuvant reagent. Compounds, 1 and 1a, inhibited xanthine oxidase activity and increased superoxide dismutase (SOD), glutathione peroxidase and catalase indicating that both compounds scavenged reactive oxygen species (ROS).

Animals↗
PubMed2004

Effects of garlic extract consumption on plasma and erythrocyte antioxidant parameters in atherosclerotic patients.

Effects of ingesting garlic extract on plasma and erythrocyte antioxidant parameters of atherosclerotic patients were investigated in this study. Eleven patients with atherosclerosis participated in the study. They ingested a dose of 1 ml/kg body weight of garlic extract daily for 6 months (study period). Before and after this period, fasting blood samples were obtained, and oxidant (malondialdehyde, MDA and xanthine oxidase, XO) and antioxidant (superoxide dismutase, SOD and glutathione peroxidase, GSH-Px) parameters were studied in plasma and erythrocytes obtained from the patients. Blood samples obtained from 11 healthy subjects served as the controls. Plasma XO activity and MDA levels were higher, but plasma and erythrocyte GSH-Px activities were lower, in patients with atherosclerosis relative to those of the control group. Our results showed that ingestion of garlic extract leads to significantly lowered plasma and erythrocyte MDA levels in the patients even in the absence of changes in antioxidant enzyme activities. Our results also demonstrated the presence of oxidant stress in blood samples from patients with atherosclerosis, but ingesting garlic extract prevented oxidation reactions by eliminating this oxidant stress. Thus, it is possible that reduced peroxidation processes may play a part in some of the beneficial effects of garlic in atherosclerotic diseases.

Aged↗
PubMed1981

Pulsed EPR studies of peroxide-activated cytochrome c peroxidase and of the mercaptoethanol derivative of Neurospora tyrosinase.

We have measured the linear electric field effect for peroxide-activated yeast cytochrome c peroxidase and for the mercaptoethanol derivative of Neurospora tyrosinase. Although both of these materials have EPR spectra resembling those of free radicals, the linear electric field effect measurements demonstrate that there is a metal ion associated with the paramagnetic centers. In addition, we have also observed superhyperfine interactions with 14N nuclei.

Catechol Oxidase↗
PubMed1987

Corticotropin-releasing factor-containing afferents to the inferior colliculus of the rat brain.

Using a modified cobalt-glucose oxidase-diaminobenzidine (Co-GOD) method in a combination of horseradish peroxidase (HRP) retrograde tracing and immunohistochemistry, a widespread localization of corticotropin releasing factor-like immunoreactive (CRFI) structures in the rat inferior colliculus (IC), and a CRFI-containing pathway from the subthalamus and the hypothalamus to the IC have been observed. By means of the modified Co-GOD method, CRFI cells were detected in almost all the subdivisions of the IC, including the dorsomedial part of the central nucleus, the ventrolateral part of the central nucleus, the pericentral nucleus and the external nucleus. Neural processes with CRFI were observed in all of the above areas. Following HRP injection into the IC, double-labeled cells which contained a homogeneous brown immunoreaction product of CRF and a granular black reaction product of retrogradely transported HRP were identified in the lateral hypothalamic area (LH), zona incerta (ZI) and perifornical hypothalamic area (PeF). These double-labeled cells provide direct evidence for CRFI projections from the LH, ZI and PeF to the IC. Thus, the present study supports the view that CRF may act as a neurotransmitter or neuromodulator in the brain.

Animals↗
PubMed1996

Reduced enzymatic antioxidant defense mechanism in kidney tissues from gentamicin-treated guinea pigs: effects of vitamins E and C.

In this study, the activities of major enzymes participating in free radical metabolism (xanthine oxidase, XO; Cu,Zn and Mn superoxide dismutases, SOD; glutathione peroxidase, GSH-Px; catalase, CAT) were measured in kidney tissues from guinea pigs treated with gentamicin alone (200 mg/kg/day), gentamicin plus vitamin C (600 mg/kg/day), gentamicin plus vitamin E (400 mg/kg/day), and gentamicin plus vitamins C and E together for 10 days, and from animals treated with physiological saline solution alone during this period. We found no significant differences between control and gentamicin groups with respect to XO and Cu,Zn-SOD activities. However, the activities of Mn-SOD, GSH-Px, and CAT were found to be significantly depressed in the gentamicin-treated group relative to controls. In the gentamicin plus vitamin C group, the renal tissue Mn-SOD activity was found to be higher as compared with control and gentamicin groups. In this group, XO, GSH-Px and CAT activities were also higher than in the gentamicin-treated group, but no statistically significant differences existed between the values of this group and controls. Similar results were also observed in the gentamicin plus vitamin E group for Mn-SOD, GSH-Px, CAT, and XO. In this group, the Cu,Zn-SOD activity was found to be decreased as compared with control and gentamicin groups. In the gentamicin plus vitamins C and E group, the Cu,Zn-SOD activity was found to be decreased, the XO activity to be unchanged, and Mn-SOD, GSH-Px, and CAT activities to be increased as compared with the gentamicin and control groups. The results suggest that the enzymatic antioxidant defense system was significantly disturbed because of the suppressed activities of Mn-SOD, GSH-Px, and CAT in the kidney tissues from animals treated with gentamicin. However, vitamins C and E given concurrently with gentamicin completely abrogated this enzymatic suppression.

Animals↗
PubMed1983

[Comparative studies of the reliability of results in determining blood glucose by 2 methods].

Comparative studies are reported on the reliability of the results in the determination of blood glucose by glucosooxidase-peroxidase and o-toluidine methods. Both methods have a good correlation. r = 0.9575 with n = 61. The results indicate that the GOD/POD method and o-toluidine method have a good reproducibility in time and series and high accuracy. Due to the poorer toxicity of GOD/POD-method its broader implementation in routine practice is recommended.

Blood Glucose↗
PubMed1996

The role of peroxidase-catalyzed activation of aromatic amines in breast cancer.

Aromatic amines are mammary carcinogens in rodents and exposure to aromatic amines may be associated with increased risk of breast cancer in women. Peroxidases present in milk can oxidize aromatic amines to reactive electrophiles which bind to DNA and induce mutations. Hydrogen peroxide, required for peroxidase-dependent oxidations, is supplied by milk xanthine oxidase and by the respiratory burst of neutrophils, cells which are present in milk and activated by exposure to it. In this paper, I propose that lactoperoxidase and myeloperoxidase activate aromatic amines, within the breast ducts, and that these enzymes play a crucial role in the chemical induction of breast cancer.

Amines↗
PubMed1987

The bactericidal mechanisms of polymorphonuclear leukocytes against Bacteroides fragilis: significance of the oxygen-dependent system.

The mechanism by which polymorphonuclear leukocytes (PMNs) kill ingested Bacteroides fragilis was examined using PMNs from patients with chronic granulomatous disease (CGD) which is an inherited disease characterized by the defect of their PMNs in oxygen-radical generation. The phagocytosis of B. fragilis by PMNs from CGD patients was comparable to that by normal PMNs. Although CGD cells killed B. fragilis to some extent, they did so less effectively than the normal PMNS. B. fragilis was killed by a xanthine oxidase system that generates oxygen radicals. When PMNs were incubated with opsonized B. fragilis, B. fragilis triggered the release of O2- and H2O2 from normal PMNs. Thus, normal PMNs appear to kill B. fragilis by both oxygen-dependent and oxygen-independent mechanisms.

Bacteroides fragilis↗
PubMed1983

[Seasonal features of the effect of low temperature on cerebral monoamine oxidase activity and sensitivity of the rat to hyperoxia].

During winter-spring period, animals staying for three days at 2 degrees C develop changes in the substrate specificity of the rat brain mitochondria type A monoamine oxidase. Activity of the blood serum glucose-6-phosphate dehydrogenase, total peroxidase activity and extraerythrocyte hemoglobin level increase as a result of erythrocyte membrane damage. Rat hyperbaric oxygen sensitivity during this period increases. In autumn, 3-day cold exposure causes no changes in the above biochemical indices or hyperbaric oxygen sensitivity.

Acclimatization↗
PubMed1993

A discontinuous luminometric assay for monoamine oxidase.

A simple, sensitive and convenient discontinuous luminometric assay for monoamine oxidase (MAO) is described. It is based on measurement of the light production from the peroxidase-catalysed chemiluminescent oxidation of 5-amino-2,3-dihydro-1,4-phthalazinedione (luminol) by the hydrogen peroxide produced in the MAO reaction. The procedure is suitable for use with a wide range of MAO substrates, although 5-hydroxytryptamine, adrenaline and noradrenaline are too readily oxidized by hydrogen peroxide to be used. A particular advantage of this procedure is that it is applicable to the oxidation of substrates which do not yield products, such as an aldehyde or free ammonia, which form the basis of several alternative substrate-independent assay procedures. The application of the procedure to assay the oxidation of benzylamine, tyramine and 2-n-pentylaminoacetamide (milacemide) by a crude mitochondrial preparation from rat liver and purified ox liver MAO-B is demonstrated.

Animals↗
PubMed1994

Effects of a lactoperoxidase-system-containing toothpaste on dental plaque and whole saliva in vivo.

The effects of a lactoperoxidase-system-containing toothpaste. Biotene, on saliva and dental plaque were studied. In a double-blind crossover study 20 healthy volunteers used an experimental (comprising the complete peroxidase system) or a placebo (without lactoperoxidase, KSCN, and glucose oxidase) toothpaste twice daily for 2 weeks separated by a 2-week washout period. At base lines and at the end of both test periods saliva and plaque samples were collected, and plaque pH changes were monitored. Saliva was analyzed for hypothiocyanite (HOSCN/OSCN-) and thiocyanate (SCN-) concentrations and salivary peroxidase activity. The amount of total streptococci, mutans streptococci, lactobacilli, and total anaerobic flora was determined both in saliva and in plaque samples. The accumulation and the acidogenicity of plaque were also quantitated. A 2-week daily use of Biotene had no effect on salivary flow rate, peroxidase activity, HOSCN/OSCN-, SCN-, or any of the monitored bacterial counts compared with the placebo toothpaste. The accumulation of dental plaque was not affected by the lactoperoxidase-system-containing toothpaste. The acidogenicity of plaque did not change significantly, nor did the two test dentifrices differ in their ability to inhibit the plaque pH drop caused by sucrose in subjects with normal salivary flow rate.

Adolescent↗