Red Cell Antioxidant Enzymes Research Articles

Red cell antioxidant enzymes and prognostic indexes in patients with burns

Red cell superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were measured in 66 burned patients (57 men, 9 women, age 16–78 years). BSAB varied from 15 to 93% and ABSI from 3 to 14 points. In the first week after injury the activity of SOD was significantly decreased as compared with the activity of the enzymes in the control group and was also below the reference values. Later the activity of SOD increased up to the normal range. The activity of CAT followed a similar pattern but the differences were not significant. No significant changes in red cell GPX were found during the monitored period. We did not find any significant association between the antioxidant enzyme activities and the markers of burns severity. On the other side there was a significant indirect association between the change of SOD activity (calculated as a difference between the first week values after the injury and the activities measured later) and BSAB.

Antimalarial and antioxidant activities of methanolic extract of Nigella sativa seeds (black cumin) in mice infected with Plasmodium yoelli nigeriensis

The antimalarial and antioxidant activities of methanolic extract of Nigella sativa seeds (MENS) were investigated against established malaria infection in vivo using Swiss albino mice. The antimalarial activity of the extract against Plasmodium yoelli nigeriensis (P. yoelli) was assessed using the Rane test procedure. Chloroquine (CQ)-treated group served as positive control. The extract, at a dose of 1.25 g/kg body weight significantly (p<0.05) suppressed P. yoelli infection in the mice by 94%, while CQ, the reference drug, produced 86% suppression when compared to the untreated group after the fifth day of treatment. P. yoelli infection caused a significant (p<0.05) increase in the levels of red cell and hepatic malondialdehyde (MDA), an index of lipid peroxidation (LPO) in the mice. Serum and hepatic LPO levels were increased by 71% and 113%, respectively, in the untreated infected mice. Furthermore, P. yoelli infection caused a significant (p<0.05) decrease in the activities of superoxide dismutase, catalase, glutathione-S-transferase and the level of reduced glutathione in tissues of the mice. Treatment with MENS significantly (p<0.05) attenuated the serum and hepatic MDA levels in P. yoelli-infected mice. In addition, MENS restored the activities of red cell antioxidant enzymes in the infected mice to near normal. Moreover, MENS was found to be more effective than CQ in parasite clearance and, in the restoration of altered biochemical indices by P. yoelli infection. These results suggest that N. sativa seeds have strong antioxidant property and, may be a good phytotherapeutic agent against Plasmodium infection in malaria.

Monitoring antioxidant enzymes in red cells during allergen immunotherapy

The aim of this report was to answer the question how specific immunotherapy influences the antioxidant enzyme system in patients with respiratory allergy and in longer perspective to find markers suitable to assess the efficacy of treatment. In open prospective randomised study 28 patients (18 females and 10 males, age 14-48 years) with seasonal respiratory allergy were treated with allergen immunotherapy. Subjects received subcutaneous therapy with allergens absorbed on calcium phoshate or aluminium hydroxide and were analyzed by the established protocol at the beginning, after three and 12 month of the treatment. In all treatment group red cell superoxide dismutase and glutathione peroxidase activities were in the normal range in allergic patients both before and during the treatment. Catalase activity in the allergic patients was lower as compared with controls and a significant increase of the enzyme activity occurred during and at the end of the treatment. In patients treated with calcium phosphate adsorbed allergen there was a continous increase of catalase activity from beginning up to the end of observation. In the case of the aluminium hydroxide treatment there was an increase from the baseline values up in the third month of the treatment and a decrease on the 12th month. In summary, the present results open the question that allergen immunotherapy may cause imbalance of oxidants and antioxidants. To support our findings larger controlled field studies are needed.

The secondary alcohol and aglycone metabolites of doxorubicin alter metabolism of human erythrocytes.

Anthracyclines, a class of antitumor drugs widely used for the treatment of solid and hematological malignancies, cause a cumulative dose-dependent cardiac toxicity whose biochemical basis is unclear. Recent studies of the role of the metabolites of anthracyclines, i.e., the alcohol metabolite doxorubicinol and aglycone metabolites, have suggested new hypotheses about the mechanisms of anthracycline cardiotoxicity. In the present study, human red blood cells were used as a cell model. Exposure (1 h at 37 C) of intact human red blood cells to doxorubicinol (40 M) and to aglycone derivatives of doxorubicin (40 M) induced, compared with untreated red cells: i) a ~2-fold stimulation of the pentose phosphate pathway (PPP) and ii) a marked inhibition of the red cell antioxidant enzymes, glutathione peroxidase (~20%) and superoxide dismutase (~60%). In contrast to doxorubicin-derived metabolites, doxorubicin itself induced a slighter PPP stimulation (~35%) and this metabolic event was not associated with any alteration in glutathione reductase, glutathione peroxidase, catalase or superoxide dismutase activity. Furthermore, the interaction of hemoglobin with doxorubicin and its metabolites induced a significant increase (~22%) in oxygen affinity compared with hemoglobin incubated without drugs. On the basis of the results obtained in the present study, a new hypothesis, involving doxorubicinol and aglycone metabolites, has been proposed to clarify the mechanisms responsible for the doxorubicin-induced red blood cell toxicity.

An insulin sensitizer improves the free radical defense system potential and insulin sensitivity in high fructose-fed rats.

Recently there has been growing interest in the effects of antioxidants on insulin activity. In the present study, we investigated the effect of metformin on free radical activity and insulin sensitivity in high fructose-fed rats, a diet that leads to insulin resistance. The animals were divided into four groups (n = 16 per group; experiment duration = 6 weeks): the control (C) group received a standard diet; the control metformin (CM) group was fed a control diet and received metformin (200 mg x kg(-1) x day(-1) in water); the fructose control (FT) group was fed a diet in which fructose composed 56.8% of the total carbohydrates; and the fructose metformin (FM) group received high-fructose diet and metformin (200 mg x kg(-1) x day(-1) in water). The glucose clamp technique was used to determine insulin sensitivity in eight animals per group. Metabolic and oxidative stress parameters were measured in the remaining rats. In the FT rats, insulin resistance, lower red cell CuZn superoxide dismutase activity and lower blood reduced glutathione were observed. Metformin treatment improved both the insulin activity and the antioxidant defense system. In the CM group, metformin had no effect on metabolic parameters, but improved red cell antioxidant enzyme activities and the blood GSH level, which suggests that it has an antioxidant activity independent of its effect on insulin activity.