scholarly journals Significance of alterations in hepatic antioxidant enzymes. Primacy of glutathione peroxidase

1988 ◽  
Vol 251 (3) ◽  
pp. 913-917 ◽  
Author(s):  
T W Simmons ◽  
I S Jamall

The relative contributions of catalase and the selenoenzyme glutathione peroxidase (GSH-Px) were elucidated in the rat liver by selectively modulating the activities of these enzymes using dietary selenium (Se) and the catalase inhibitor 3-amino-1,2,4-triazole (3-AT). Increased peroxidation occurred only in Se-deficient rats with markedly reduced cytosolic and mitochondrial GSH-Px activities. Although 3-AT treatment resulted in a 75% reduction of hepatic catalase activity and also a 20% reduction of both cytosolic and mitochondrial superoxide dismutase (SOD) activity, no incremental increase in peroxidation was observed over that associated with Se deficiency. In Se-deficient animals, treatment with 3-AT resulted in a doubling of cytosolic GSH-Px. This was associated with a 49% elevation in hepatic Se suggesting that increased Se may have contributed to the enhanced GSH-Px activity. These results suggest that GSH-Px plays the pivotal role in preventing hepatic peroxidation. Furthermore, the effects of 3-AT in vivo are not restricted to inhibition of catalase activity insofar as it also affects cytosolic GSH-Px activity and cytosolic and mitochondrial SOD activities.

Hepatology ◽  
2010 ◽  
Vol 52 (1) ◽  
pp. 303-312 ◽  
Author(s):  
M. Isabel Lucena ◽  
Elena García-Martín ◽  
Raúl J. Andrade ◽  
Carmen Martínez ◽  
Camilla Stephens ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
De-Lu Ma ◽  
Mai Chen ◽  
Chen X. Su ◽  
Brett J. West

Deacetylasperulosidic acid (DAA) is a major phytochemical constituent ofMorinda citrifolia(noni) fruit. Noni juice has demonstrated antioxidant activityin vivoand in human trials. To evaluate the role of DAA in this antioxidant activity, Wistar rats were fed 0 (control group), 15, 30, or 60 mg/kg body weight per day for 7 days. Afterwards, serum malondialdehyde concentration and superoxide dismutase and glutathione peroxidase activities were measured and compared among groups. A dose-dependent reduction in malondialdehyde was evident as well as a dose-dependent increase in superoxide dismutase activity. DAA ingestion did not influence serum glutathione peroxidase activity. These results suggest that DAA contributes to the antioxidant activity of noni juice by increasing superoxide dismutase activity. The fact that malondialdehyde concentrations declined with increased DAA dose, despite the lack of glutathione peroxidase-inducing activity, suggests that DAA may also increase catalase activity. It has been previously reported that noni juice increases catalase activityin vivobut additional research is required to confirm the effect of DAA on catalase. Even so, the current findings do explain a possible mechanism of action for the antioxidant properties of noni juice that have been observed in human clinical trials.


HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 546-548
Author(s):  
Suping Zhou ◽  
Roger J. Sauvé ◽  
Margaret T. Mmbaga ◽  
Chaim Frenkel

Leucanthemum maximum `Silver Princess' plants, that were gradually acclimated for 7 days at 10 °C followed by 28 days at 7 °C, were subjected to the following cold treatments: 30 days at 4 °C; 4 or 5 days at 0 °C and for 3 hours at –1 °C to identify cold inducible proteins that may be responsible for cold tolerance in this cold tolerant species. Change in antioxidant enzymes activity in fully expanded leaves was assessed after each treatment. Catalase activity began to increase after 30 days at 4 °C and reached its peak after a 5-day exposure to 0 °C. The activity of cellular glutathione peroxidase and glutathione reductase significantly increased after a 4-day exposure to 0 °C. Changes in activity of four active superoxide dismutase isoforms, one basic guaiacol peroxidase and two o-dianisine peroxidase isoforms were also detected following the full series of cold treatments (30 days at 4 °C; 4 or 5 days at 0 °C and for 3 hours at –1 °C).


1991 ◽  
Vol 37 (11) ◽  
pp. 1932-1937 ◽  
Author(s):  
L Guemouri ◽  
Y Artur ◽  
B Herbeth ◽  
C Jeandel ◽  
G Cuny ◽  
...  

Abstract We studied the biological variability of blood superoxide dismutase (SOD; EC 1.15.1.1), glutathione peroxidase (GPX; EC 1.11.1.9), and catalase (CAT; EC 1.11.1.6) in a sample of 1836 apparently health subjects, ages 4-97 years. SOD and GPX activities were assayed in plasma (P) and erythrocytes (E) by automated methods, and CAT was measured in erythrocytes by a manual technique. No statistically significant variation of these antioxidant enzyme activities according to gender was demonstrated, except for E-GPX, which was slightly but significantly higher in women than in men (P less than 0.001). Activities appear rather stable in adults less than 65 years old, but decrease for most enzymes in the elderly. There is no evidence that weight, blood pressure, or menopause influences the antioxidant enzymes' activities. In girls ages 10-14 years, E-SOD activity is reduced by 16% (P less than 0.05) after menarche. Variations related to smoking and alcohol consumption are slight and concern only P-SOD and P-GPX, respectively. Conversely, intake of some drugs (e.g., anti-inflammatory agents, antidepressants, and thyroid hormones) modifies activity of some of the three enzymes. E-SOD positively correlates with P-SOD (r = 0.216, P less than 0.001) and E-CAT (r = 0.123, P less than 0.001), and E-GPX with P-GPX (r = 0.218, P less than 0.001). Finally, we propose reference intervals for activities of the three antioxidant enzymes in blood in individuals less than 65 years old.


2005 ◽  
Vol 75 (4) ◽  
pp. 227-234 ◽  
Author(s):  
Hosotani ◽  
Yoshida ◽  
Kitagawa

To evaluate the effects of supplementing diets with carotenoid and ascorbic acid (AsA) on the antioxidative ability of Osteogenic Disorder-Shionogi (ODS) rats, we added synthetic b-carotene (bC), AsA, and powders of persimmon (Ka) and pods (Po) containing bC and AsA to the diet and obtained the following results. The urinary 8-hydroxydeoxyguanosine (8-OHdG) concentration was low in the –betaC•AsA and +AsA groups but high in the +betaC. AsA, +Ka, and +Po groups. The thiobarbituric acid-reactive substances (TBARS) in both the liver and skin were higher in the –betaC•AsA group than in the +betaC•AsA group and were low in the +Ka and +Po groups. As antioxidant enzymes, glutathione peroxidase (GSH-Px) activity was high in the +betaC•AsA group, low in the –betaC•AsA group in both the skin and liver, and also high in the + Ka and +Po group in the liver. Superoxide dismutase (SOD) activity was high in the –betaC•AsA group and low in the +betaC•AsA and +Ka groups in both the skin and liver. Catalase (CAT) activity in the liver was low in the –betaC•AsA, + AsA, and +betaC groups and high in the +betaC•AsA and + Po groups. These results confirmed that the administration of betaC, AsA, and persimmons and pods increases antioxidative ability in the skin and liver of ultraviolet-b(UV-B)-irradiated ODS rats.


2012 ◽  
Vol 93 (1) ◽  
pp. 116-119
Author(s):  
F Kh Kamilov ◽  
A N Mamtsev ◽  
V N Kozlov ◽  
G M Abdullina ◽  
O V Lobyreva

Aim. To determine the activity of antioxidant enzymes in rat liver tissue on the background of thiamazole hypothyroidism, and also after its correction with iodine-containing organo-mineral complexes. Methods. Studies were conducted on rats, which were divided into four groups: the first group - the control, in animals of the second, third and fourth groups hypothyroidism was induced by daily intragastric administration of thiamazole at a dose 2.5 mg per 100 g body weight for the duration of 3 weeks. Beginning from the 22-day of the experiment the animals of the fourth group for the duration of a month received a biologically active additive in a dose that provides the daily requirement of iodine in rats, while the animals of the third group were on the standard diet of the vivarium. The activity of superoxide dismutase and glutathione peroxidase was determined using a set of reagents «RANSOD Randox» manufactured by «Laboratories Ltd.», the catalase activity was determined by the method of M.A. Korolyuk. Results. Experimental hypothyroidism in rats was characterized by a decrease in the concentrations of free thyroxine, an increase in the content of total triiodothyronine and thyroid-stimulating hormone. In animals treated with tiamazol, the superoxide dismutase activity was 85.6% of the activity level of the control animals, glutathione activity - 77.3% of the level of intact animals. The catalase activity in hypothyroidism decreased significantly - down to 40% of the control level (p ≤0.001). In the liver homogenate of rats, treated for 1 month with «iodine biopolymer» after hypothyroidism induction, the superoxide dismutase activity almost reached the control values and accounted for 95.5% of the activity of intact animals. The activity of glutathione peroxidase and catalase, was even slightly higher than the control values, reaching 115.6 and 112.7% of levels of activity in the control group, respectively (p ≤0,05). At the same time in the animals, which were on a standard diet, the activity of the studied enzymes remained below the control values, with the catalase activity - significantly lower (49.9% of the control, p ≤0,001). Conclusion. The introduction of an iodine-containing biologically active compound on the background of hypothyroidism made it possible to restore the activity of thyroid-dependant antioxidant enzymes, to normalize the functional state of the pituitary-thyroid system and to inhibit the processes of lipid peroxidation in the liver the of animals.


2020 ◽  
Vol 13 (1) ◽  
pp. 76-83
Author(s):  
Aline Maria Brito Lucas ◽  
Joana Varlla de Lacerda Alexandre ◽  
Maria Thalyne Silva Araújo ◽  
Cicera Edna Barbosa David ◽  
Yuana Ivia Ponte Viana ◽  
...  

Background: Cardiac hypertrophy involves marked wall thickening or chamber enlargement. If sustained, this condition will lead to dysfunctional mitochondria and oxidative stress. Mitochondria have ATP-sensitive K+ channels (mitoKATP) in the inner membrane that modulate the redox status of the cell. Objective: We investigated the in vivo effects of mitoKATP opening on oxidative stress in isoproterenol- induced cardiac hypertrophy. Methods: Cardiac hypertrophy was induced in Swiss mice treated intraperitoneally with isoproterenol (ISO - 30 mg/kg/day) for 8 days. From day 4, diazoxide (DZX - 5 mg/kg/day) was used in order to open mitoKATP (a clinically relevant therapy scheme) and 5-hydroxydecanoate (5HD - 5 mg/kg/day) or glibenclamide (GLI - 3 mg/kg/day) were used as mitoKATP blockers. Results: Isoproterenol-treated mice had elevated heart weight/tibia length ratios (HW/TL). Additionally, hypertrophic hearts had elevated levels of carbonylated proteins and Thiobarbituric Acid Reactive Substances (TBARS), markers of protein and lipid oxidation. In contrast, mitoKATP opening with DZX avoided ISO effects on gross hypertrophic markers (HW/TL), carbonylated proteins and TBARS, in a manner reversed by 5HD and GLI. Moreover, DZX improved mitochondrial superoxide dismutase activity. This effect was also blocked by 5HD and GLI. Additionally, ex vivo treatment of isoproterenol- induced hypertrophic cardiac tissue with DZX decreased H2O2 production in a manner sensitive to 5HD, indicating that this drug also acutely avoids oxidative stress. Conclusion: Our results suggest that diazoxide blocks oxidative stress and reverses cardiac hypertrophy. This pharmacological intervention could be a potential therapeutic strategy to prevent oxidative stress associated with cardiac hypertrophy.


Sign in / Sign up

Export Citation Format

Share Document