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1.
Nitric oxide (NO) a free radical having both cytoprotective as well as tumor promoting agent is formed from l-arginine by converting it to l-citrulline via nitric oxide synthase enzymes. The reaction product of nitric oxide with superoxide generates potent oxidizing agent, peroxynitrite which is the main mediator of tissue and cellular injury. Peroxynitrite is reactive towards many biomolecules which includes amino acids, nucleic acid bases; metal containing compounds, etc. NO metabolites may play a key role in mediating many of the genotoxic/carcinogenic effects as DNA damage, protein or lipid modification, etc. The basic reactions of nitric oxide can be divided as direct effect of the radical where it alone plays a role in either damaging or protecting the cell milieu and an indirect effect in which the byproducts of nitric oxide formed by convergence of two independent radical generating pathways play the role in biological reactions which mainly involve oxidative and nitrosative stress. Nitric oxide is also capable of directly interacting with mitochondria through inhibition of respiration or by permeability transition. Reaction of nitric oxide with metal ions include its direct interaction with the metals or with oxo complexes thereby reducing them to lower valent state. Excessive production of nitric oxide can be studied by inhibiting the synthetic pathway of nitric oxide using both selective or specific nitric oxide synthase inhibitor or non-selective nitric oxide synthase inhibitor with respect to isoforms of nitric oxide.  相似文献   

2.
Free radical mediated pathological processes may have a role in schizophrenia. Free radicals (oxy radicals, such as superoxide, hydroxyl ions and nitric oxide) cause cell injury, when they are generated in excess or when the antioxidant defense is impaired. Both these processes seem to be affected in schizophrenia. In this study we investigated erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities as antioxidant enzymes, malondialdehyde (MDA) as a sign of lipid peroxidation in schizophrenic patients. Activities of superoxide dismutase, catalase and malondialdehyde were greater in patients compared with the control group which may reflect increased oxidative stress in the brain tissue of schizophrenics. In the patient group erythrocyte SOD and CAT activities were weakly negative correlated with MDA concentration. These data reveal that antioxidant defense mechanisms might be impaired in schizophrenic patients. These findings also provide a theoretical basis for the development of novel therapeutic strategies, such as antioxidant supplementation.  相似文献   

3.
Crystal aggregation and retention are critical events for the formation of kidney stones. There is a close association between crystal development and free radical activity in vivo. In the present study 30 subjects presenting with urolithiasis were included. Serum levels of total lipid peroxides, nitric oxide (as nitrite), α-tocopherol, plasma ascorbic acid (vitamin C) and erythrocyte superoxide dismutase activity were measured. These findings were compared with 30 age matched control subjects irrespective of sex. Student's ‘t’ test was applied for statistical analysis. There was a significant increase in lipid peroxides (p<0.001), where as significant decrease in nitrite (p<0.01) and α-tocopherol (p<0.001) levels were observed. Plasma ascorbate (p>0.05) and erythrocyte superoxide dismutase activity (p>0.05) was also found to be decreased but the difference was not statistically significant which suggests that oxidative stress is evident in urolithiasis with depletion in antioxidant status where as decrease in nitric oxide may be less abetting in disease condition.  相似文献   

4.
Picrorhiza kurrooa is mentioned in Ayurveda for the treatment of many disorders, but it has not been subjected to systematic scientific investigations to assess its antidiabetic effect. The oral administration of aqueous and methanol extracts of P. kurrooa rhizomes (250 and 500 mg / kg body weight / day) for 15 days significantly reduced blood glucose, glycosylated haemoglobin and increased total hemoglobin, plasma insulin in alloxan-induced diabetes in albino rats. The treatment also showed significant correction in the level of nitric oxide radicals, superoxide radicals, peroxynitrite radical, lipid peroxidation, glutathione, glutathione reductase, glutathione-S-transferase, glutathione peroxidase, superoxide dismutase and catalase in the pancreas of alloxan diabetic rats.  相似文献   

5.
Hemodialysis represents a chronic stress status for its recipients. Many hypotheses state that this may be associated with oxidative stress. Thus, there may be deficiency of antioxidants like erythrocytic superoxide dismutase, catalase, vitamin E or increased generation of free radicals like superoxide anions. A study was carried out to investigate oxidant and antioxidant status in chronic renal failure patients undergoing hemodialysis and effect of vitamin E supplementation on these two status. Blood samples were collected from patients before and after hemodialysis and from controls. The samples were analyzed for quantitation of MDA as index of lipid peroxide, nitric oxide, vitamin E, vitamin C and enzymatic antioxidants namely erythrocyte SOD and catalase. As compared to controls, the levels of serum MDA were significantly increased and activities of erythrocyte SOD and catalase, levels of serum nitric oxide, serum vitamin E and plasma vitamin C were significantly decreased both before and after hemodialysis. The efficiency of vitamin E therapy in hemodialysis patients was assessed by re-evaluating oxidant and antioxidant status of same patients after supplementation of vitamin E. Vitamin E supplementation caused decrease in serum MDA and increase in levels of serum nitric oxide, vitamin E, vitamin C and activities of erythrocytic SOD and catalase. Our results suggest the presence of oxidative stress and the possible preventive role of vitamin E therapy in hemodialysis patients.  相似文献   

6.
Pretreatment of an ethanolic extract of leaf ofPiper betle linn at a dose of 200mg/kg body weight, orally administered to rats for ten consecutive days, was found to possess a significant protective action against gastric lesions induced by indomethacin. The extract pretreatment resulted in significant increase in superoxide dismutase (SOD) and catalase (CAT) activity, increase in mucus, hexosamine and total thiol group content, but marked reduction in oxidatively damaged protein and peroxidised lipid levels as compared to untreated ulcerated control. The extract was also found to possess both superoxide and hydroxyl free radical scavenging action. The present observations establish the efficacy of the extract in prevention of experimentally induced peptic ulcer by indomethacin and antioxidant property appears to be predominantly responsible for such cytoprotective activity in the experimental model.  相似文献   

7.
This study was undertaken to evaluate the levels of plasma magnesium, lipid peroxides, nitric oxide end products, erythrocyte membrane lipid peroxides, erythrocyte reduced glutathione and erythrocyte superoxide dismutase activity in type-2 diabetes mellitus patients. 60 patients with type-2 diabetes mellitus and 30 healthy control subjects were included in this study. Among 60 type-2 diabetic patients, 30 patients were without complication and 30 patients were with various complications. Decreased levels of plasma magnesium, erythrocyte reduced glutathione and erythrocyte superoxide dismutase activity while increased levels of plasma lipid peroxides, nitric oxide end products and erythrocyte membrane lipid peroxides were observed in patients with type-2 diabetes mellitus. We propose that, under the shadow of hypomagnesaemia, there is excessive production of reactive oxygen species and reactive nitrogen species as reflected by elevated lipid peroxides and nitric oxide end products concomitant with dwindled antioxidants and suggest their association with late complications in type-2 diabetes mellitus.  相似文献   

8.
The effect of Emblica officinalis fruit extract (EFE) against alcohol-induced hepatic damage in rats was investigated in the present study. In vitro studies showed that EFE possesses antioxidant as well nitric oxide (NO) scavenging activity. In vivo administration of alcohol (5 g/kg b.wt/day) for 60 days resulted increased liver lipid peroxidation, protein carbonyls, nitrite plus nitrate levels. Alcohol administration also significantly lowers the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase and reduced glutathione as compared with control rats. Administration of EFE (250 mg/kg body weight) to alcoholic rats significantly brought the plasma enzymes towards near normal level and also significantly reduced the levels of lipid peroxidation, protein carbonyls and restored the enzymic and non-enzymatic antioxidants level. This observation was supplemented by histopathological examination in liver. Our data indicate that the tannoid, flavonoid and NO scavenging compounds present in EFE may offer protection against free radical mediated oxidative stress in rat hepatocytes of animals with alcohol-induced liver injury.  相似文献   

9.
Iron is an essential nutrient for a number of cellular activities. However, excess cellular iron can be toxic by producing reactive oxygen species (ROS) such as superoxide anion (O2−) and hydroxyl radical (HO·) that damage proteins, lipids and DNA. Mutagenic and genotoxic end products of lipid peroxidation can induce the decline of mitochondrial respiration and are associated with various human ailments including aging, neurodegenerative disorders, cancer etc. Zingiber officinale Roscoe (ginger) is a widely used spice around the world. The protective effect of aqueous ethanol extract of Z. officinale against ROS-induced in vitro lipid peroxidation and DNA damage was evaluated in this study. The lipid peroxidation was induced by hydroxyl radical generated from Fenton’s reaction in rat liver and brain homogenates and mitochondrial fraction (isolated from rat liver). The DNA protection was evaluated using H2O2-induced changes in pBR-322 plasmid and Fenton reaction-induced DNA fragmentation in rat liver. The results indicated that Z. officinale significantly (P<0.001) protected the lipid peroxidation in all the tissue homogenate/mitochondria. The extract at 2 and 0.5 mg/ml could protect 92 % of the lipid peroxidation in brain homogenate and liver mitochondria respectively. The percent inhibition of lipid peroxidation at 1mg/ml of Z. officinale in the liver homogenate was 94 %. However, the extract could partially alleviate the DNA damage. The protective mechanism can be correlated to the radical scavenging property of Z. officinale. The results of the study suggest the possible nutraceutical role of Z. officinale against the oxidative stress induced human ailments.  相似文献   

10.
Normal polymorpho nuclear leucocytes (PMNL) when assaulted with diabetic serum factorin-vitro, recorded enhanced generation of oxygen free radical, and lysosomal degranulation. It also caused a decrease in the cytosolic superoxide dismutase activity. Time-plot studies revealed PMNL susceptibility to diabetic serum factor for oxidative injury and concomitant decrease in SOD, consequential for lysosomal degranulation.  相似文献   

11.
The present study was undertaken to evaluate the levels of serum lipid peroxide, nitric oxide end poducts, erythrocytic superoxide dismutase activity and serum α 1-antitrypsin in smokers. Total 90 active cigarette smokers were subdivided into Group I (subjects with smoking habit of less than 10 cigarettes per day) and Group II (with smoking habit of more than 10 cigarettes per day). In both groups lipid peroxide and nitric oxide end products were significantly increased with significantly decrease in erythrocytic superoxide dismutase activity and serum α 1-antitrypsin as compared to controls. Our findings show enhanced oxidative stress and reduced α 1-antitrypsin in cigarette smokers. Further increase in number of cigarettes per day exacerbates the oxidative stress with decrease in α 1-antitrypsin.  相似文献   

12.
Oxidative stress in Parkinson’s disease   总被引：1，自引：0，他引：1  
Oxidative stress contributes to the cascade, leading to dopamine cell degeneration in Parkinson’s disease. However, oxidative stress is intimately linked to other components of the degenerative process, such as mitochondrial dysfunction, excitotoxicity, nitric oxide toxicity and inflammation. It is therefore difficult to determine whether oxidative stress leads to or is a consequence of, these events. Oxidative stress was assessed by estimating lipid peroxidation product in the form of thiobarbituric acid reactive substances, nitric oxide in the form of nitrite & nitrate. Enzymatic antioxidants in the form of superoxide dismutase, glutathione peroxidase, catalase, ceruloplasmin and non enzymatic antioxidant vitamins e.g. vitamin E and C in either serum or plasma or erythrocyte in 40 patients of Parkinson’s disease in the age group 40–80 years. Trace elements e.g. copper, zinc and selenium were also estimated. Plasma thiobarbituric acid reactive substances and nitric oxide levels were Significantly high but superoxide dismutase, glutathione peroxidase, catalase, ceruloplasmin, vitamin-E, vitamin-C, copper, zinc and selenium levels were significantly low in Parkinson’s disease when compared with control subjects. Present study showed that elevated oxidative stress may be playing a role in dopaminergic neuronal loss in substentia nigra pars compacta and involved in pathogenesis of the Parkinson’s disease.  相似文献   

13.
Guggulsterone, a mixture of cis (E) and trans (Z) isomers (7∶3 w/w) was synthesized from 16-DPA. The isomers were separated by column chromatography and evaluated for cardioprotective and antioxidant activities. Myocardial necrosis induced by isoproterenol in rats caused marked increase in serum creatine phosphokinase and glutamate pyruvate transaminase. Simultaneously in ischemic heart, phospholipase, xanthine oxidase and lipid peroxides were enhanced following depletion of glycogen, phospholipids and cholesterol. Treatment with guggulsterone and its both isomers at the dose of 50 mg/kg po., significantly protected cardiac damage as assessed by the reversal of blood and heart biochemical parameters in ischemic rats. The cardioprotective activity of guggulsterone and of both the isomers were compared with that of gemfibrozil at the same doses. Guggulsterone and both the isomers at tested concentrations (5–20mM) inhibited oxidative degradation of lipids in human low-density lipoprotein and rat liver microsomes induced by metal ionsin vitro. The drug counteracted against the generation of superoxide anions (O2) and hydroxyl radicals (OH−) in non-enzymic test systems. It is suggested that cardioprotective and antioxidant activities of synthetic guggulsterone and guggulsterone obtained from gum resinCommiphora mukul that contains isomers E & Z in the ratio of 46∶54w/w are the same.  相似文献   

14.
Ocimum sanctum leaves have been traditionally used in treatment of diabetes mellitus. Dietary supplementation of fresh tulsi leaves in a dose of 2 gm/kg BW for 30 days led to significant lowering of blood glucose levels in test group. Intake ofOcimum sanctum also led to significant increase in levels of superoxide dismutase, reduced glutathione and total thiols, but marked reduction in peroxiodised lipid levels as compared to untreated control group. The leaves were found to possess both superoxide and hydroxyl free radical scavenging action. The present observations establish the efficacy ofOcimum sanctum leaves in lowering blood glucose levels and antioxidant property appears to be predominantly responsible for hypoglycemic effect.  相似文献   

15.
In the present study, the role of serum lipid peroxide and serum nitric oxide as oxidants and erythrocytic superoxide dismutase & serum vitamin E as antioxidants were determined in the 50 neonates with hypoxic ischaemic encephalopathy. (HIE) as against 25 healthy neonates as controls 50 patients of HIE were further divided into two groups i. e. mild and moderate HIE patients. All subjects were in the age group of 37–41 weeks of gestation. The levels of serum lipid peroxide, serum nitric oxide and erythrocytic superoxide dismutase were significantly elevated in both groups of neonates with HIE than those of controls (P<0.001), whereas serum vitamin E levels were significantly decreased in both groups of HIE patients than those of controls (P<0.001). A positive correlation was obtained between serum lipid peroxide and erythrocytic superoxide dismutase (r=+0.86). Alterations in the status of oxidants and antioxidants indicate role of free radicals in the development of HIE.  相似文献   

16.
4mg and 8mg monosodium glutamate per gram body weight was administered subcutaneously for 6 consecutive days to normal adult male mice and its effect was seen on 31st day after the last injection on some antioxidant enzymes in heart. A significant dose dependent increase in lipid peroxidation and xanthine oxidase level was observed, whereas the activity of free radical scavenging enzymes such as superoxide dismutase and catalase was decreased in both monosodium glutamate treated groups (Group-2 and Group-3). So, the present work suggested that monosodium glutamate at dose level of 4mg/g body weight and above induced oxidative stress in the cardiac tissue by changing the activity of free radical initiating enzyme such as xanthine oxidase and scavenging enzymes like superoxide dismutase and catalase.  相似文献   

17.
The antidyslipidemic activity of Hibiscus rosa sinensis (Malvaceae) root extract has been studied in alloxan induced diabetic rats. In this model, oral administration of root extract (500 mg/kg bw. p.o.) for 15 days resulted in significant decreased in the levels of blood glucose, plasma lipids and reactivated post heparin lipoprotein lipase activity in alloxan induced diabetic rats. Furthermore, the root extract (50–500 μg) when tested for its antioxidant activity, inhibited the generation of super oxide anions and hydroxyl radicals, in both enzymic and non enzymic systems in vitro. The results of the present study demonstrated antidyslipidemic and antioxidant activities in root extract of H. rosa sinensis which could be used in prevention of diabetic-dyslipidemia and related complications.  相似文献   

18.
A total of 75 healthy male dry cell industry workers exposed to carbon for 5, 8 and 10 years were compared with 48 controls matched for age and economic status with respect to free radical generation, lipid peroxidation and antioxidant levels. Lymphocytes were seperated from the whole blood and used for estimation of free radicals and antioxidants. Plasma lipid peroxidation products were estimated in the form of thiobarbituric acid reactive substances. Significant increase in free radical generation and lipid peroxidation products were observed in carbon exposed population than controls, and the increase was found to be significant with increase in the period of exposure. The levels of antioxidants i.e., superoxide dismutase (SOD) and catalase were found to decrease with the increase in exposure to carbon in industrial workers. These results suggest that exposure to carbon augments free radical generation, lipid peroxidation and promotes decline in antioxidant enzymes.  相似文献   

19.
New findings on organization of blood cell cytoskeleton represent an exciting aspect of modem cell biology and hematology, which is an interesting investigation to study diabetes. The present study was undertaken in 150 subjects. Out of these, 30 subjects were controls (Group I) and 30 were type-2 diabetics without any complication (Group II), while remaining 90 subjects were type-2 diabetics with complication (Group III). We determined erythrocyte spectrin and hemoglobin glycosylation and also estimated plasma lipid peroxide, nitric oxide and erythrocyte glutathione peroxidase activity to assess the status of oxidative stress. There was a significant increase in spectrin (P<0.001) and hemoglobin (P<0.001) glycosylation in Group II and III as compared to Group I and spectrin glycosylation was nearly three times more as compared to hemoglobin, whereas plasma levels of lipid peroxide (P<0.001) as well as nitric oxide (P<0.001) were found to be significantly increased and GPx activity (P<0.001) was significantly decreased in Group II and III as compared to Group I. However, it was also observed that spectrin (P>0.05) and hemoglobin (P>0.05) glycosylation was not significantly different in Group II and III. In contrast, there was significant rise in lipid peroxide (P<0.001), nitric oxide (P<0.001) and fall in GPx activity (P<0.001) in Group III when compared to Group II. Increased erythrocyte protein glycosylation and oxidative stress is clearly evident from our study. However, to understand the exact interplay between these two mechanisms, further studies are required.  相似文献   

20.
The aim of this study was to monitor serum nitric oxide levels at various times, intraoperatively and following liver transplantation in humans. Nitric oxide production was assessed by cadmium reduction method in 15 patients undergoing liver transplantation. We observed strong correlation between nitric oxide production and allograft rejection. Sustained rise in nitric oxide level after transplantation might provide an indication of acute allograft rejection. Therefore measurement of nitric oxide, a stable end product appears to be an excellent marker that can help in the development of strategies intended to improve graft viability and patient’s survival.  相似文献   

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