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1.
The effect of methionine or citrate on antioxidant defense system has been studied in urolithic rat. Liver weight and its protein concentration did not change in the rats fed with calculi producing diet (CPD) when compared to normal diet fed rats. Feeding rats along with citrate (c-CPD) or methionine (m-CPD) improved their body weight gain. Liver microsomes and mitochondria fractions of CPD and c-CPD fed groups showed increased susceptibility for lipid peroxidation in presence of ascorbate and t-butyl hydroperoxide when compared to either control or m-CPD fed groups. Increased superoxide dismutase and xanthine oxidase activities, decreased catalase, glutathione peroxidase and glucose-6-phosphate dehydrogenase activities, decreased concentrations of reduced glutathione, total thiols, ascorbic acid and vitamin-E and increased formation of hydroxyl radical, hydroperoxides and diene conjugates were observed in the liver of both CPD fed group as well as c-CPD fed group. Except SOD and xanthine oxidase, all other parameters were normalized in m-CPD fed group. This suggested that feeding methionine reduced the susceptibility for lipid peroxidation by restoration of the level of free radical scavengers.  相似文献   

2.
Antiradical activity of nimesulide, a commonly used COX-2 specific inhibitor, was estimated in vitro by 1, 1 diphenyl-2-picrylhydrazyl (DPPH) assay, nitroblue tetrazolium reduction assay and lipid peroxidation assay, respectively. The biochemistry of antioxidant functions of nimesulide was also investigated under control and inflammatory conditions, caused by intratracheal instillation of lipopolysaccharide (LPS). Pro-inflammatory conditions generally end up in oxidative insults, which have been suggested to be the cause of multiple organ failure in inflammation. A primary defense, constituted of antioxidant enzymes, against this oxidative damage has evolved in the body. In this study, male Wistar rats were orally administered with nimesulide (9 mg/kg/twice daily for 1 week), followed by intratracheal instillation with 2 microg of LPS and after 18 hr, antioxidant defense system and lipid peroxidation were measured in liver, lungs and kidneys. Nimesulide pretreatment was found to protect the tissue from enhanced levels of lipid peroxidation, and also stimulated the levels of glutathione-S-transferase (GST) in liver and glutathione reductase in kidneys. Surprisingly, nimesulide oral feeding also significantly suppressed superoxide dismutase (SOD) activity in all the three organs. Although, in our study, nimesulide proved to be an inducer of GST (a marker for chemoprevention) and a scavenger of superoxide anions at higher concentrations (> 250 microM), but the relevance of suppression of SOD enzyme activity, which may contribute to the drug's toxic effects cannot be ignored. The work suggests that further long term studies are needed to confirm nimesulide as a safe drug.  相似文献   

3.
Exposure of isolated rat hepatocytes to allyl alcohol (AA), diethyl maleate (DEM) and bromoisovalerylurea (BIU) induced lipid peroxidation, depletion of free protein thiols to about 50% of the control value and cell death. Vitamin E completely prevented lipid peroxidation, protein thiol depletion and cell death. A low concentration (0.1 mM) of the lipophylic disulfide, disulfiram (DSF), also prevented the induction of lipid peroxidation by the hepatotoxins; however, in the presence of DSF, protein thiol depletion and cell death occurred more rapidly. Incubation of cells with a high concentration (10 mM) of DSF alone led to 100% depletion of protein thiols and cell death, which could not be prevented by vitamin E. The level of free protein thiols in cells, decreased to 50% by exposure to AA, DEM and BIU, could be reversed to 75% of the initial level by dithiothreitol (DTT) treatment, indicating that the protein thiols were partially modified into disulfides and partially into other, stable thiol adducts. The 100% depletion of protein thiols by DSF was completely reversed by DTT treatment. The involvement of lipid peroxidation in protein thiol depletion was studied by measuring the effect of a lipid peroxidation product, 4-hydroxynonenal (4-HNE), on protein thiols in a cell free liver fraction. 4-HNE did not induce lipid peroxidation in this system, but protein thiols were depleted to 30% of the initial value, irrespective of the presence of vitamin E. DTT treatment could reverse this for only 25%. Similar, DSF-induced protein thiol depletion could be reversed completely by DTT. We conclude that (at least) two types of protein thiol modifications can occur after exposure of hepatocytes to toxic compounds: one due to interaction of endogeneously generated lipid peroxidation products with protein thiols, which is not reversible by the action of DTT, and one due to a disulfide interchange between disulfides like DSF and protein thiols, which can be reversed by the action of DTT.  相似文献   

4.
The effect of dipalmitoyl phosphatidylcholine (DPPC) and its structural fragments--phosphatidic acid (PA) and choline chloride--on the ascorbate-dependent mice liver microsomal lipid peroxidation (LP) has been studied at the different LP rate. At DPPC, PA and choline chloride introduction into the incubation medium before the onset of peroxidation induction DPPC causes the more considerable inhibition of LP than PA each separate fragment. The inhibition effect of DPPC is lower than PA or choline chloride when DPPC, PA and choline chloride added on the background of developing process of peroxidation (e.i. after LP induction). A specific regulatory role of PC in the normal cell membrane LP process and during pathologic development is under discussion.  相似文献   

5.
吴鑫  周茜  唐珊珊  陈作红 《菌物学报》2016,35(10):1244-1249
鹅膏肽类毒素是蘑菇中毒导致死亡的最主要因素,用于鹅膏中毒治疗的解毒药物已有大量报道,水飞蓟宾(silibinin,SIL)被认为是目前最有效的解毒药物。灵芝作为我国传统的中药真菌,具有良好的保肝护肝作用。本文开展灵芝主要活性成分灵芝总三萜(Ganoderma total triterpenoids,GTT)和对照药物水飞蓟宾对α-鹅膏毒肽(α-amanitin,α-AMA)中毒小鼠所致肝损伤的保护作用及其抗氧化机理研究,结果表明α-鹅膏毒肽中毒小鼠经灵芝总三萜和水飞蓟宾治疗后小鼠血清中的ALT和AST活性显著降低,小鼠死亡率降低40%-50%,病理组织切片观察表明能明显减轻肝组织损伤的程度,说明灵芝总三萜与水飞蓟宾一样,对α-鹅膏毒肽中毒小鼠的肝具有很好的保护作用。灵芝总三萜给药组和水飞蓟宾给药组能显著增加肝组织中SOD和CAT的活性,显著降低肝脏中MDA含量,表明灵芝总三萜和水飞蓟宾具有抗氧化和自由基清除剂作用,能减轻α-鹅膏毒肽所引起的脂质过氧化伤害作用。  相似文献   

6.
The administration of a single dose of diethyl maleate (DEM) to fed rats elicited a drastic decrease in the content of reduced glutathione (GSH) both in liver and lung tissues after 6 h of treatment. Cellular GSH depletion induced by DEM was accompanied by a marked increase in pulmonary lipid peroxidation which was completely abolished by (+)-cyanidanol-3, without changes in the liver. Superoxide dismutase (SOD) activity remained unchanged in both tissues in this situation. Hepatic and pulmonary GSH depletion induced by a second dose of DEM given 24 h later produced a further increase in lung lipid peroxidation and a diminution of pulmonary SOD activity. In this condition, hepatic lipid peroxidation and SOD activity were not altered. These results indicate that lung and liver tissues exhibit a different lipid peroxidative response to chemically-induced GSH depletion.  相似文献   

7.
The effect of exercise on oxidant stress and on alterations in antioxidant defense in elderly has been investigated extensively. However, the impact of regularly performed long-term physical activity starting from adulthood and prolonged up to the old age is not yet clear. We have investigated the changes in the activities of antioxidant enzymes - superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) - and lipid peroxidation in various tissues of rats which had performed (old-trained) or had not performed (old-control) regular swimming exercise for one year. These animals were compared with young-sedentary rats. Increased lipid peroxidation was observed with ageing in all tissues (heart, liver, kidney, striated muscle) and swimming had no additional effect on this elevation of lipid peroxidation. Heart and striated muscle SOD activites, and striated muscle CAT activity increased as a consequence of ageing, whereas kidney and liver CAT activities, as well as GPx activities in kidney, liver, lung and heart were significantly decreased compared to young controls. Lung and heart SOD, liver CAT activities as well as GPx activities in liver, lung and heart were increased significantly in rats which performed exercise during ageing, compared to the old-control group. These findings suggest that lifelong exercise can improve the antioxidant defense in many tissues without constituting any additional oxidant stress.  相似文献   

8.
This study evaluates the hepatoprotective effect of carotenoids against isoniazid (INH) and rifampicin (RIF). Thirty-six adult rats were divided into the following 4 groups: (1) control group treated with normal saline; (2) INH + RIF group treated with 50?mg·(kg body mass)-1·day-1 of INH and RIF each; (3) INH + RIF+ carotenoids group treated with 50?mg·(kg body mass)-1·day-1 of INH and RIF each and 10?mg·(kg body mass)-1·day-1 of carotenoids; and (4) carotenoids group treated with 10?mg·(kg body mass)-1·day-1 of carotenoids for 28?days intragastrically. Oxidative stress and antioxidant levels in liver and blood, liver histology and change in transaminases were measured in all the above-mentioned groups. There was an increase in lipid peroxidation with a reduction in thiols, catalase, and superoxide dismutase (SOD) in the liver and blood of rats accompanied by an increase in transaminases, bilirubin, and alkaline phosphatase. Treatment with carotenoids along with INH + RIF partially reversed lipid peroxidation, thiols, catalase, and SOD in the liver and blood of rats. Elevated levels of the enzymes in serum were also reversed partially by this treatment. The degree of necrosis, portal triaditis, and inflammation were also lowered in the carotenoids group. In conclusion, carotenoids supplementation in INH + RIF treated rats showed partial protection.  相似文献   

9.
The effects of selenium (Se) on antioxidant defense system in liver and kidneys of rats with cadmium (Cd)-induced toxicity were examined. Cd exposure (15 mg Cd/kg b.m./day as CdCl(2) for 4 weeks) resulted in increased lipid peroxidation (LP) in both organs (p<0.005 and p<0.01). Vitamin C (Vit C) was decreased in the liver (p<0.005), whereas vitamin E (Vit E) was increased in the liver and kidneys (p<0.005 and p<0.05) of Cd-exposed animals. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were decreased in both tissues (p<0.05 and p<0.005), whereas catalase (CAT) activity was decreased only in liver (p<0.005). Glutathione S-transferase (GST) increased in both tissues (p<0.005 and p<0.01). Treatment with Se (0.5 mg Se/kg b.m./day as Na(2)SeO(3) for 4 weeks) significantly increased liver and kidneys SOD and GSH-Px activities (p<0.05 to p<0.005), as well as CAT and GST activities only in the liver (p<0.01). In animals exposed to Se, both the concentrations of Vit C (p<0.01) and Vit E (p<0.005) were increased in both tissues. Co-treatment with Se resulted in reversal of oxidative stress with significant decline in analyzed tissues Cd burden. Our results show that Se may ameliorate Cd-induced oxidative stress by decreasing LP and altering antioxidant defense system in rat liver and kidneys and that Se demonstrates the protective effect from cadmium-induced oxidative damage.  相似文献   

10.
The effect of elevated levels of dietary cadmium on lipid peroxidation in the liver and kidneys of a small rodent, the bank vole, was determined in the present study. Males and females, aged 1 month, were given diets containing 0.40 and 80 mg Cd per kg; liver and kidneys were removed for TBA-RS as well as iron, copper, zinc, cadmium and metallothionein analyses at the end of 6 weeks. Dietary Cd significantly decreased the TBA-RS level in the liver and kidneys of both sexes; however, this effect appeared to be dose-dependent only for the male liver. The changes in hepatic and renal TBA-RS paralleled closely those of tissue iron. Copper concentration decreased significantly only in the male liver, while hepatic and renal zinc were not influenced by dietary Cd. The concentrations of Cd and metallothionein in the liver and kidneys increased significantly in a dose-dependent fashion. Regression analysis confirmed that TBA-RS in both organs correlated closely with iron. The data suggest that dietary Cd decreases hepatic and renal lipid peroxidation indirectly, through lowering the tissue iron concentration.  相似文献   

11.
In this study, the modulator effect of caffeic acid phenethyl ester (CAPE) on the oxidative nephrotoxicity of gentamicin in the kidneys of rats was investigated by determining indices of lipid peroxidation and the activities of antioxidant enzymes as well as by histological analyses. Forty female Wistar albino rats were randomly divided into four groups, namely control, gentamicin, CAPE, and gentamicin plus CAPE. On the 12th day of the study, all rats were sacrificed and then blood samples and kidneys were taken. Lipid peroxidation and nitric oxide levels, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) enzyme activities, and histological evaluation were measured in kidneys of rats. Levels of blood urea nitrogen and creatinine were studied in serum. CAPE with gentamicin caused decreases in lipid peroxidation, nitric oxide, urea nitrogen, and creatinine levels, although it caused increases in CAT, GSH-Px, and SOD activities when compared with gentamicin alone. In addition, on histological evaluation, the renal damage caused by gentamicin alone appeared much higher than that caused by CAPE plus gentamicin. It is concluded that oxidative stress plays a critical role in causing gentamicin nephrotoxicity and that this nephrotoxicity may be significantly reduced by CAPE.  相似文献   

12.
The effect of the liver mitogen, lead nitrate [Pb(NO3)2], on protein-undernutrition-induced increased lipid peroxidation and reduced antioxidants levels was investigated in rats. Animals were divided into four groups: A, B, C, and D of five animals each. Animals in groups C and D were placed on a low-protein diet (5% casein) and animals in groups A and B were maintained on a normal diet (16% casein) for 14 wk and fed ad libitum. Animals in groups B and D were each given a single intravenous injection of Pb(NO3)2 (100 μmol/kg body weight) 72 h before sacrifice. The results confirm that protein undernutrition (PU) induced an increase in lipid peroxidation with concomitant reductions in catalase (CAT) activity, glutathione (GSH) level, and superoxide dismutase (SOD) activity. Lead (Pb) treatment, however, provoked increased lipid peroxidation, CAT activity, and GSH level but resulted in reduced SOD activity in both normal and PU-rats. These results suggest that Pb exacerbates liver lipid peroxidation in PU rats and suggests the involvement of free radicals in the pathogenesis of Pb poisoning. In addition, the results show that Pb affects well-fed and PU rats in similar ways but that the CAT activity of PU rats is more sensitive to the effect of Pb than that of normal rats.  相似文献   

13.
镉长期暴露对黑斑蛙的氧化胁迫和抗氧化能力的影响   总被引:1,自引:0,他引:1  
在实验条件下,将黑斑蛙暴露于12.5mg/L和25.0mg/L浓度的镉溶液中30d,分别测定了黑斑蛙在暴露10、20和30d时肝、肾组织中镉(Cd)含量、过氧化产物丙二醛(MDA)的含量、还原型谷胱甘肽(GSH)含量和超氧化物歧化酶(SOD)活性,以探讨镉对机体的脂质过氧化作用及机体的抗氧化损伤机制。实验结果表明,不同剂量组黑斑蛙肝、肾镉含量、MDA含量均随着镉暴露时间的延长而升高,且肝MDA含量与镉在肝中的蓄积量呈显著正相关(R^2=0.8643,n=9)。肝脏GSH含量随镉暴露时间的延长而被显著诱导,且与MDA含量呈显著正相关(R^2=0.5933,n=9);肾GSH含量则随暴露时间的延长而显著下降,与MDA含量呈显著负相关(R^2=0.8609,n=9)。不同剂量组肝SOD活性随镉暴露时间的延长而升高,肾SOD活性在高剂量组随镉暴露时间的延长表现为先升高后回落下降的趋势。可见,在镉的长期暴露下,细胞膜过氧化增强是镉伤害机体的主要原因,而GSH含量、SOD活性的升高则可能是机体抗过氧化的机理之一。  相似文献   

14.
果醋对高脂小鼠血脂和肝脏脂质过氧化的影响   总被引:1,自引:0,他引:1  
本文目的在于研究果醋对高脂小鼠血脂和肝脏脂质过氧化的影响。长期饲喂高脂饲料造成小鼠高血脂和肝脏脂质过氧化模型,预防性给予果醋,测定血清中总胆固醇(TC),甘油三酯(TG),低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C)的含量;测定肝脏中脂质过氧化终产物丙二醛(地A)的含量和超氧化物歧化酶(SOD)的活性。结果证明果醋可以明显降低高脂小鼠血清中TC,LDL含量和肝脏组织中MDA含量,提高肝脏组织SOD活性。  相似文献   

15.
During studies of the mechanism by which hemolysis is induced in irradiated human erythrocytes in vitro, several inducements of membrane lipid peroxidation and protective effects of vitamin E (V.E) and superoxide dismutase (SOD) were investigated. Findings were: (1) Before hemolysis, K+ release from erythrocytes induced by radiation stimulated hemolysis but was inhibited by V.E or SOD. (2) Lipid peroxidation of mitochondria induced by Fe3+, ADP, and superoxide (O2-) generating system, and lipid peroxidation of microsome induced by O2- generating system, were also inhibited by V.E or SOD. (3) X-ray or 60Co gamma-ray radiation stimulated lipid peroxidation of liver homogenate, microsome, and liposome. Some of this peroxidation was inhibited by V.E. or SOD. These results suggest that O2- and/or OH formation by radiation induces membrane lipid peroxidation, which causes deterioration of membrane resulting in change of ion permeability and consequent hemolysis.  相似文献   

16.
The indirect effect of rat skin ultraviolet (UV) irradiation on lipid peroxidation and enzymatic systems of the liver has been studied. The processes of lipid peroxidation have been intensified after 72 hours of UV-irradiation, which is evidently due both to the activation of enzymatic system of initiation and propagation of lipid peroxidation and to the parallel decrease of the activity of enzymatic system regulation of given process in liver.  相似文献   

17.
Radioprotective effect of aqueous extract of Ocimum sanctum (40 mg/kg body weight, for 15 days) in mice exposed to high-doses (3.7 MBq) of oral 131iodine was investigated by studying the organ weights, lipid peroxidation and antioxidant defense enzymes in various target organs like liver, kidneys, salivary glands and stomach at 24 hr after exposure in adult Swiss mice. The mean weight of the salivary glands showed significant increase after 131iodine administration. 131iodine exposure significantly increased lipid peroxidation in kidneys and salivary glands in comparison to control animals. Pretreatment with O. sanctum in radioiodine exposed group showed significant reduction in lipid peroxidation in both kidneys and salivary glands. In liver, reduced glutathione (GSH) levels showed significant reduction after radioiodine exposure while pretreatment with O. sanctum exhibited less depletion in GSH level even after 131iodine exposure. However, no such changes were observed in stomach. The results indicate the possibility of using aqueous extract of O. sanctum for ameliorating 131Iodine induced damage to the salivary glands.  相似文献   

18.
In recent years, N-acetyl-L-cysteine (NAC) has been widely investigated as a potentially useful protective and antioxidative agent to be applied in many pathological states. The aim of the present work was further evaluation of the mechanisms of the NAC protective effect under carbon tetrachloride-induced acute liver injuries in rats. The rat treatment with CCl4 (4 g/kg, intragastrically) caused pronounced hepatolysis observed as an increase in blood plasma bilirubin levels and hepatic enzyme activities, which agreed with numerous previous observations. The rat intoxication was accompanied by an enhancement of membrane lipid peroxidation (1.4-fold) and protein oxidative damage (protein carbonyl group and mixed protein-glutathione disulphide formations) in the rat liver. The levels of nitric oxide in blood plasma and liver tissue significantly increased (5.3- and 1.5-fold, respectively) as blood plasma triacylglycerols decreased (1.6-fold). The NAC administration to control and intoxicated animals (three times at doses of 150 mg/kg) elevated low-molecular-weight thiols in the liver. The NAC administration under CCl4-induced intoxication prevented oxidative damage of liver cells, decreased membrane lipid peroxidation, protein carbonyls and mixed protein-glutathione disulphides formation, and partially normalized plasma triacylglycerols. At the same time the NAC treatment of intoxicated animals did not produce a marked decrease of the elevated levels of blood plasma ALT and AST activities and bilirubin. The in vitro exposure of human red blood cells to NAC increased the cellular low-molecular-weight thiol levels and retarded tert-butylhydroperoxide-induced cellular thiol depletion and membrane lipid peroxidation as well as effectively inhibited hypochlorous acid-induced erythrocyte lysis. Thus, NAC can replenish non-protein cellular thiols and protect membrane lipids and proteins due to its direct radical-scavenging properties, but it did not attenuate hepatotoxicity in the acute rat CCl4-intoxication model.  相似文献   

19.
Superoxide dismutases (SOD) mimetics have been shown to be protective against cell injury caused by reactive oxygen species. The objective of this study was to investigate the effects of the manganese (III) tetrakis(N-methyl-2-pyridyl)porphyrin (MnTMPyP) on CYP2E1-dependent toxicity. The synergistic toxicity of iron and arachidonic acid has been associated with oxidative stress and lipid peroxidation in HepG2 cells that overexpress CYP2E1. Iron plus arachidonic acid caused loss of viability, increased lipid peroxidation and reactive oxygen species generation, and mitochondrial membrane injury in these cells. MnTMPyP partially protected against the decrease in cell viability, the enhanced lipid peroxidation and oxygen radical production, and the loss of mitochondrial membrane potential. The effect of MnTMPyP on arachidonic acid (absence of iron) toxicity was also evaluated. Arachidonic acid also caused toxicity, lipid peroxidation and reduction of the mitochondrial membrane potential. However, in this model, all of these alterations were actually enhanced by MnTMPyP. MnTMPyP also enhanced toxicity in CYP2E1-expressing HepG2 cells depleted of reduced glutathione (GSH). MnCl(2) had little or no effect on the toxicity by arachidonic acid, and MnTMPyP itself did not peroxidize arachidonic acid. MnTMPyP, an SOD mimetic that also scavenges hydrogen peroxide and peroxynitrite, thus showed an antioxidant and protective effect against iron plus arachidonic acid toxicity, but a pro-oxidant and cytotoxic effect against arachidonic acid toxicity in CYP2E1-expressing cells. These different actions may relate to the ability of MnTMPyP to either scavenge or produce free radicals in cells depending upon the prevailing MnTMPyP oxidation-reduction pathways. MnTMPyP and related manganese porphyrin compounds may have potential clinical utility against diseases associated with the overproduction of reactive oxygen species such as ethanol-induced liver injury but it is clear that further investigation of all the pathways of manganese porphyrin oxidation-reduction are necessary.  相似文献   

20.
The herb, Cajanus indicus L, is well known for its hepatoprotective action. A 43 kD protein has been isolated, purified and partially sequenced from the leaves of this herb. A number of in vivo and in vitro studies carried out in our laboratory suggest that this protein might be a major component responsible for the hepatoprotective action of the herb. Our successive studies have been designed to evaluate the potential efficacy of this protein in protecting the hepatic as well as renal tissues from the sodium fluoride (NaF) induced oxidative stress. The experimental groups of mice were exposed to NaF at a dose of 600 ppm through drinking water for one week. This exposure significantly altered the activities of the antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione reductase (GR) and the cellular metabolites such as reduced glutathione (GSH), oxidized glutathione (GSSG), total thiols, lipid peroxidation end products in liver and kidney compared to the normal mice. Intraperitoneal administration of the protein at a dose of 2 mg/kg body weight for seven days followed by NaF treatment (600 ppm for next seven days) normalized the activities of the hepato-renal antioxidant enzymes, the level of cellular metabolites and lipid peroxidation end products. Post treatment with the protein for four days showed that it could help recovering the damages after NaF administration. Time-course study suggests that the protein could stimulate the recovery of both the organs faster than natural process. Effects of a known antioxidant, vitamin E, and a non-relevant protein, bovine serum albumin (BSA) have been included in the study to validate the experimental data. Combining all, result suggests that NaF could induce severe oxidative stress both in the liver and kidney tissues in mice and the protein possessed the ability to attenuate that hepato-renal toxic effect of NaF probably via its antioxidant activity.  相似文献   

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