Lipid peroxidative damage on cadmium exposure and alterations in antioxidantsystem in rat erythrocytes: A study with relation to time

Cadmium induced lipid peroxidation (LPO) and the activity of antioxidantenzymes after the administration of a single dose of CdCl 2 (0.4 mg kg body wt, ip) was studied in rat erythrocytes.Cd intoxication increased erythrocyte LPO along with a decrease insuperoxide dismutase (SOD) up to three days of Cd treatment. Thedecrease in erythrocyte catalase (CAT) activity was marked within9 h of Cd intoxication. After three days of Cd treatment, LPOdecreased towards normal, along with an increase in erythrocyteSOC and CAT activity. Blood glutathione (GSH) decreased significantlywithin 24 h of Cd treatment, followed by an increase towards normal.Erythrocyte glutathione S-transferase (GST) activity increased up to10 days of Cd intoxication, probably in an attempt to reduce Cd toxicity.Serum glutamate pyruvate transaminase (SGPT), serum alkaline phosphatase(SALP) and serum bilirubin increased up to 10 days of Cd intoxication.Blood urea increased significantly up to three days, followed by a decreasetowards normal. The results show that Cd induced LPO was associated with adecrease in antioxidant enzymes and GSH in erythrocytes; as these antioxidantsincrease in erythrocytes with recovery from Cd intoxication, the Cd inducedLPO reversed towards normal. The increase in the SGPT, SALP and serum bilirubincorrelated with LPO. The results suggest that Cd intoxication induces oxidativestress and alters the antioxidant system, resulting in oxidative damage torat erythrocytes. © Rapid Science 1998     

Stability of the anti-oxidative enzymes in aqueous and detergent solution

Activities of the anti-oxidative enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase were studied in rat tissues to determine the ability of detergents both to solubilize the enzymes and also to stabilize enzyme activity. Rat brain, heart and liver were homogenized in 0.1M KCl, 0.1% sodium dodecyl sulfate, 0.1% lubrol, or 0.1% cetyl-trimethylammonium bromide. In general lubrol was more effective than the other solutions in solubilizing GPx and catalase. Lubrol and 0.1M KCl were equally effective in solubilizing SOD. The highest enzyme activities were (1) SOD: 2484 ng/mg (brain), 2501 ng/mg (heart), and 5586 ng/mg (liver); (2) GPx: 224 mU/mg (brain), 1870 mU/mg (heart), and 7332 mU/mg (liver); (3) catalase: 2.8 mU/mg (brain), 10.6 mU/mg (heart), and 309 mU/mg (liver). While cetyl trimethylammonium bromide is marginally better than sodium dodecyl sulfate in solubilizing active enzyme, neither ionic detergent has any advantage over lubrol or 0.1M KCl. For catalase and GPx, enzyme activity loss with time is biphasic. After initial, rapid activity loss (1–5 days for GPx and 7–10 days for catalase) the differences noted among the homogenizing solutions disappear and very little if any activity loss is noted over the next 2–3 weeks. For catalase and GPx, only baseline enzyme activity from t = 0 – 3 weeks is found in the most chaotropic solution, 0.1% sodium dodecyl sulfate while biphasic activity loss is most pronounced in 0.1% lubrol. These results may indicate active GPx and catalase species stabilized by a lipid-like environment. Correlatingin vitro catalase or GPx measurements within vivo anti-oxidative protection may underestimate tissue defences.     

Antioxidant enzyme activities in subcellular fractions of larvae of the black swallowtail butterfly,Papilio polyxenes

The black swallowtail butterfly, Papilio polyxenes, larvae are specialized feeders of pro-oxidant rich plants of Apiaceae and Rutaceae. An important defense against toxic forms of oxygen species generated by ingestion of the pro-oxidants, are the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), GSH-dependent glutathione peroxidases (selenium-dependent glutathione peroxidase [GPOX] and peroxidase activity of selenium-independent glutathione-S-transferase [GT_px]), and glutathione reductase (GR). The subcellular distribution of these enzymes in black swallowtail larvae was investigated and was found to resemble the patterns described for larvae of two other lepidopteran species: the southern armyworm, Spodoptera eridania, and the cabbage looper, Trichoplusia ni. The confinement of SOD in the cytosol and mitochondria was typically eukaryotic, but the relative proportion (1:1) was markedly different from the mammalian pattern (4:1; cytosol:mitochondria). The most obvious difference between the black swallowtail and other lepidoptera as a group, and mammalian species, is in very wide intracellular distributions of CAT, GTpx, and GR in insect species. Insects possess very low levels of a GPOX-like activity which reduces both H₂O₂ and organic peroxides. Consequently, insects have elaborate activities with a wide subcellular distribution of both CAT which decomposes H₂O₂, and GTpx which decomposes organic peroxides. The reduction of peroxides is dependent on GSH, which in this process is oxidized to GSSG. GR which reduces GSSG to GSH is also of wide subcellular distribution, analogous to the distribution pattern of GTpx.     

魔芋葡甘低聚糖对小鼠抗氧化酶活性的影响

研究魔芋葡甘低聚糖对小鼠血浆和肝脏中抗氧化酶活性的影响。魔芋葡甘低聚糖能有效地降低肝脏中丙二醛(MDA)的含量,提高肝脏和血浆中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)的活性。尤以高剂量组效果最好。     

Antioxidant enzyme gene expression in congestive heart failure following mycardial infarction

Increased oxidative stress and reduction in antioxidant enzymes have been suggested to be involved in the pathophysiology of congestive heart failure subsequent to myocardial infarction (MI). The objective of the present study was to characterize changes in the mRNA abundance and protein levels for the enzymatic antioxidants, superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and catalase during the sequelae of congestive heart failure in rats. MI was produced by the ligation of the left coronary artery and hearts from controls and 1, 4 and 16 week PMI groups were analyzed. Losartan treatment (2 mg/ml in drinking water, daily) was started at 4 weeks and continued for 12 weeks. The mRNA levels for SOD were reduced by about 40% at 1-week PMI, were near to the control levels at 4-week PMI and at 16 weeks PMI, the levels were reduced by about 73% below the controls. GSHPx mRNA levels remained unchanged at all time points. The mRNA levels for catalase remained unchanged at 1 and 4 weeks PMI and were significantly reduced by about 44% at 16 weeks PMI as compared to the controls. The protein levels for MnSOD, CuZnSOD, GSHPx at 1 and 16 weeks remained unchanged in treated and untreated PMI groups. However, the protein levels for catalase was significantly increased in the control and PMI groups treated with Losartan. It is concluded that changes in the SOD and catalase activities during severe heart failure correlated with changes in mRNA for these enzymes. The precise mechanism/s for the improvement in antioxidant reserve and protein levels after Losartan treatment is/are unclear at this time.     

Paclobutrazol delayed dark-induced senescence of mung bean leaves

Sixty days old mung beans Vigna radiata (L.) Wilczek were treated with soil applied paclobutrazol, at the rate of 500 μg per 10 inch pot. After seven days of application, the plants along with untreated controls were transferred to the dark for induction of senescence. The treated plants exhibited higher chlorophyll content and activity of catalase (CAT) compared to controls. In contrast, control leaves had higher activity of peroxidase (POX) and a higher content of malondialdehyde (MDA), while superoxide dismutase (SOD) activity remained unchanged. Upon transfer to dark, chlorophyll content declined in both control and treated plants but the decline was much faster in control. The activity of CAT decreased significantly in controls while POX activity and MDA content remained higher in control than in treated plants. Paclobutrazol delayed the dark-induced senescence in attached mung bean leaves in association with the maintenance of higher activity of CAT, low activity of POX, and low MDA contents. The variation in SOD activity was not discernible with senescence levels.     

Protective effect of glutathione and selenium against alloxan induced lipid peroxidation and loss of antioxidant enzymes in erythrocytes

Alloxan is a diabetogenic drug and is known to induce diabetes through generation of free radicals. The toxic oxygen species can be detoxified by antioxidant enzyme system and thus reduce the deleterious effect of lipid peroxidation. Erythrocytes exposed to alloxan induced lipid peroxidationin vivo as well asin vitro. Although alloxan treatment produced a deleterious effect on antioxidant enzymes, pretreatment with glutathione and selenium led to a recovery of the activities of superoxide dismutase and glutathione peroxidase. However, catalase activity increased on alloxan treatment. Alloxan reduced blood glucose level significantly within 60 min but thereafter a slow and steady rise was observed.     

The effects of diazinon on lipid peroxidation and antioxidant enzymes in rat heart and ameliorating role of vitamin E and vitamin C

Diazinon is one of the most widely used organophosphate insecticides (OPIs) in agriculture and public health programs. Reactive oxygen species (ROS) caused by OPIs may be involved in the toxicity of various pesticides. The aim of this study was to investigate how diazinon affects lipid peroxidation (LPO) and the antioxidant defense system in vivo and the possible ameliorating role of vitamins E and C. For this purpose, experiments were done to study the effects of DI on LPO and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in adult rat heart. Experimental groups were: (1) control group, (2) diazinon treated (DI) group, (3) DI+vitamins E and C-treated (DI+Vit) group. The levels of malondialdehyde (MDA) and the activities of SOD and CAT increased significantly in the DI group compared with the control group. The activity of SOD and the levels of MDA decreased significantly in the DI+Vit group compared with the DI group. The differences between the DI+Vit and control groups according to the MDA levels and the activities of both SOD and CAT were statistically significant. These results suggest that treating rats with a single dose of diazinon increases LPO and some antioxidant enzyme activities in the rat myocardium and, in addition, that single-dose treatment with a combination of vitamins E and C after the administration of diazinon can reduce LPO caused by diazinon, though this treatment was not sufficiently effective to reduce the values to those in control group.     

Alleviation of NaCl Stress by Pretreatment with Phytohormones in Vigna radiata

Efficiency of pretreatment as foliar spray of indole-3-acetic acid, gibberellic acid and kinetin, each ranging from 0.1 to 10.0 μM concentration, in restoring the metabolic alterations imposed by NaCl salinity was investigated in Vigna radiata (L.) Wilczek. Glycolate oxidase, superoxide dismutase, catalase and peroxidase activities increased under stress in leaves and roots also. Malondialdehyde content and total peroxide content also increased under stress. All the three hormones used were able to overcome to variable extents the adverse effects of stress imposed by NaCl to these parameters. This revised version was published online in July 2006 with corrections to the Cover Date.     

Commentary: Oxygen Radicals, A Failure Or A Success of Evolution?

Oxygen radicals are no doubt involved in the development of many pathological states. Nevertheless, the possibility that oxygen radical production was selected for during biological evolution in order to perform useful roles in relation to cellular metabolism is contemplated; previous data on this subject are briefly reviewed. The concept of an “oxygen radical cycle” is proposed as a useful theoretical model.     

Commentary: Oxygen Radicals,A Failure Or A Success of Evolution?

Oxygen radicals are no doubt involved in the development of many pathological states. Nevertheless, the possibility that oxygen radical production was selected for during biological evolution in order to perform useful roles in relation to cellular metabolism is contemplated; previous data on this subject are briefly reviewed. The concept of an “oxygen radical cycle” is proposed as a useful theoretical model.     

Responses of antioxidative system to chilling stress in two rice cultivars differing in sensitivity

The responses of antioxidative system of rice to chilling were investigated in a tolerant cultivar, Xiangnuo-1, and a susceptible cultivar, IR-50. The electrolyte leakage and malondialdehyde content of Xiangnuo-1 were little affected by chilling treatment but those of IR-50 increased. Activities of suoperoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase, and ascorbic acid content of Xiangnuo-1 were remained high, while those of IR-50 decreased under chilling. The results indicated that higher activities of defense enzymes and higher content of antioxidant under stress were associated with tolerance to chilling.     

Thiobarbituric acid-reactive material content and enzymatic protection against peroxidative damage during the course of cryogenic rabbit brain edema

The relationship between free radicals reactions and the cell detoxifying system was investigated during the development of brain edema following a cryogenic lesion in the rabbit cerebral cortex. The amount of TBA-reactive material present six hours after freezing was less than in the controls, then increased at 48 and 96 hours. The activity of superoxide dismutase (SOD) decreased 6 hours post-injury; at the same time, we observed a stimulation of catalase activity. The glutathione peroxidase activity (GSH-Px) rose 96 hours post-lesion. The decrease of TBA-reactive products could result from an elimination rate that exceeds generation.     

Effect of drought on biomass, protein content, lipid peroxidation and antioxidant enzymes in two sesame cultivars

The effects of drought on growth, protein content, lipid peroxidation, superoxide dismutase (SOD), peroxidase (POX), catalase (CAT) and polyphenol oxidase (PPO) were studied in leaves and roots of Sesamum indicum L. cvs. Darab 14 and Yekta. Four weeks after sowing, plants were grown under soil moisture corresponding to 100, 75, 50 and 25 % field capacity for next four weeks. Fresh and dry masses, and total protein content in leaves and roots decreased obviously under drought. However, several new proteins appeared and content of some proteins was affected. Measurement of malondialdehyde content in leaves and roots showed that lipid peroxidation was lower in Yekta than in Darab 14. Severe stress increased SOD, POX, CAT and PPO activities in leaves and roots, especially in Yekta. According to the present study Yekta is more resistant to drought than Darab 14.