Potential effects of L-NAME on alcohol-induced oxidative stress

AIM: Nitric oxide (NO) is a highly reactive oxidant synthesized from L-arginine by nitric oxide synthase (NOS). NO may cause injury through the generation of potent radicals. Nw-nitro-L-arginine methyl ester (L-NAME) is a non-selective inhibitor of NOS. We aimed to evaluate whether L-NAME treatment had protective effects against oxidative stress in rats intragastrically fed with ethanol during a 4 wk-period. METHODS: Thirty-six male Wistar rats were divided into 3 equal groups: group 1 (control group-isocaloric dextrose was given), group 2 (6 g/kg·d ethanol-induced group) and group 3 (both ethanol 6 g/kg·d and L-NAME 500 mg/L in drinking water-given group). Animals were sacrificed at the end of 4 wk-experimental period, and intracardiac blood and liver tissues were obtained. Biochemical measurements were performed both in plasma and in homogenized liver tissues. Alanine amino transferase (ALT), aspartate amino transferase (AST), malondialdehyde (MDA), NO, superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels were measured by spectrophotometry. RESULTS: ALT and AST in group 2 (62 U/L and 128 U/L, respectively) were higher than those in group 1 (24 U/L and 38 U/L) and group 3 (37 U/L and 81 U/L) (P<0.001 for both). Plasma and tissue levels of MDA in group 2 (4.66 μmol/L and 0.55 μmol/mg protein) were higher than in group 1 (2.65 μmol/L and 0.34 nmol/mg protein) and group 3 (3.43 μmol/L and 0.36 nmol/mg protein) (P<0.001 for both). Plasma and liver tissue levels of NO in group 2 (54.67 μmol/L and 586.50 nmol/mg protein) were higher than in group 1 (34.67 μmol/L and 435.33 nmol/mg protein) and group 3 (27.50 μmool/L and 412.75 nmol/mg protein ) (P<0.001 for both). Plasma and liver tissue SOD activities in group 2 (15.25 U/mL and 5.38 U/ mg protein, respectively) were lower than in group 1 (20.00 U/mL and 8.13 U/ mg protein) and group 3 (19.00 U/mL and 6.93 U/ mg protein) (P<0.001 for both). Plasma and liver tissue CAT activities in group 2 (145 U/mL and 37 U/ mg protein, respectively) were lower than in group 1 (176 U/mL and 73 U/mg protein) and group 3 (167 U/mL and 61 U/mg protein) (P<0.001 for both). Meanwhile, erythrocytes and liver tissue levels of GSH in group 2 (4.12 mg/g Hb and 5.38 nmol/mg protein, respectively) were lower than in group 1 (5.52 mg/g Hb and 4.49 nmol/mg protein) and group 3 (5.64 mg/g Hb and 4.18 nmol/mg protein) (P<0.001 for both). CONCLUSION: Our findings show that L-NAME may produce a restorative effect on ethanol-induced liver damage via decreasing oxidative stress and increasing antioxidant status.     

Protective effect of pineapple (Ananas cosmosus) peel extract on alcohol–induced oxidative stress in brain tissues of male albino rats

ObjectiveTo investigate the ability of pineapple peels to protect against alcohol-induced oxidative stress in brain tissues using male albino rat models.MethodsResponse surface methodology (RSM) was used to design a series of experiments to optimize treatment conditions with the aim of investigating the protective effect of pineapple peel extract on alcohol-induced oxidative stress in brain tissues. Oxidative stress was induced by oral administration of ethanol (20% w/v) at a dosage of 5 mL/kg bw. The treatment lasted for 28 days. At the end of the treatment, the rats were fasted overnight and sacrificed by cervical dislocation. Tissue homogenates were used for the assessment of protein concentration, reduced glutathione (GSH) content, catalase, and SOD.ResultsAlcohol administration caused a significant decrease (P>0.05) in GSH level in the group which was only fed alcohol. Treatment with pineapple peel extracts caused increase in GSH level in alcohol fed groups. No significant difference (P<0.05) was observed in SOD levels of the negative control and group fed on only pineapple peel extract. Elevated level of catalase was observed in the negative control but pineapple peel extract significantly reduced the levels.ConclusionsThis study indicates the protective effect of pineapple peel against alcohol-induced oxidative stress in brain tissues.     

Serum biochemical responses under oxidative stress of aspartame in wistar albino rats

ObjectiveTo study whether the oral administration of aspartame (40 mg/kg body weight) for 15 d, 30 d and 90 d have any effect on marker enzymes, some selective liver and kidney function parameter, lipid peroxidation and antioxidant status in serum. To mimic human methanol metabolism, folate deficient animals were used.MethodAnimal weight, complete hemogram, marker enzyme in serum, some selected serum profile reflect liver and kidney function, plasma corticosterone level, and in serum, lipid peroxidation, nitric oxide, enzymatic and non-enzymatic antioxidant level was measured .ResultAfter 15 d of aspartame administration animals showed a significant change in marker enzymes, and antioxidant level. However, after repeated long term administration (30 d and 90 d) showed a significant change in some selected serum profile reflects liver and kidney function, along with marker enzymes, and antioxidant level.ConclusionsThis study concludes that oral administration of aspartame (40 mg/kg body weight) causes oxidative stress in Wistar albino rats by altering their oxidant/antioxidant balance.     

氧化应激在大鼠创伤性脑损伤后应激性肝损害中的作用

目的:探讨氧化应激(OS)在大鼠创伤性脑损伤(TBI)后应激性肝损害(HSI)中的作用.方法:用改良Allen法建立TBI模型.40只健康Wister大鼠随机分为5组,正常对照组、颅脑致伤后6、12、24、48 h时相组.酶学法检测血清ATL和AST水平,ABC-ELISA法测定血清TNF-α水平.硫代巴比妥酸法测定MDA水平变化,化学发光法测定SOD水平变化.光镜及电镜下观察肝脏组织学改变.结果:颅脑致伤后12 h,各组血ALT和AST、TNF-α水平及肝组织MDA明显增加,肝组织SOD显著减少,与对照组比较差异均显著(252.92±56.29 vs 41.17±7.88;283.12±45.28vs 45.22±6.57;1138.27±212.02 vs 210.56±28.22;15.21±0.36 vs 6.14±0.25;78.13±3.12vs 135.58±5.58,P<0.01或0.05);TBI各组光镜和电镜可观察到肝组织不同程度受损.结论:TBI后早期可出现HSI,OS可能参与了其发病过程.     

Influence of sex hormonal status on alcohol-induced oxidative injury in male and female rat liver

BACKGROUND: Oxidative stress contributes to the development of liver injury after chronic alcohol intake. Women exhibit greater sensitivity to alcohol-induced liver disease than do men. The aim of the study was to determine the relationship between the sex hormone status of male and female rats and the degree of alcohol-induced oxidative stress in the liver. METHODS: Male and female rats were pair-fed a liquid diet that contained 36% of their total daily calories as ethanol (EtOH group) or maltose (control group). Blood and liver samples were collected at the end of 8 weeks of diet. RESULTS: Male EtOH rats experienced a reduction in plasma testosterone (T) and an increase in estradiol (E2) levels, with an increase in their calculated E2/T ratio with respect to their controls. Malonaldehyde (MDA) levels, an index of lipid peroxidation, and protein carbonyl content, an index of protein oxidation, in the liver were greater among the EtOH groups in females than in males. In males, an inverse correlation was found between hepatic MDA and circulating T levels, and a direct correlation was disclosed between MDA and estradiol levels. In addition, the hepatic histopathological score correlated inversely with the plasma T levels and directly with the calculated E2/T ratio, an index of feminization. CONCLUSIONS: Alcohol-induced oxidative injury, which contributes to hepatic injury in both male and female rats, is enhanced in females compared with males. A role for plasma T levels in protecting male rat liver from ethanol-induced oxidative injury can be hypothesized.     

A critical period in lifespan of male rats coincides with increased oxidative stress

The oxidative stress theory of aging has provided the best possible explanation for the processes which accompany aging and has received much support, however, in the last few years there have been questions regarding the validity of this theory. We have conducted experiments to determine an array of oxidative stress parameters in blood of male rats at various intervals (1, 4, 8, 12, 18 and 24 months) during their entire lifespan. Established protocols were used to measure plasma antioxidant capacity, erythrocyte plasma membrane redox system (PMRS), lipid and protein oxidation in erythrocytes and plasma, and erythrocyte glutathione (GSH). Our results on the total plasma antioxidant potential, PMRS in erythrocytes, protein and lipid peroxidation, and intracellular reduced GSH provide evidence that oxidative stress is minimal till approximately one-third of the total lifespan (8 months) and there is a spurt in oxidative stress between 8 and 12 months. The identification of a period (corresponding to 8–12 months) in the lifespan of rats coinciding with an spurt in oxidative stress is an interesting finding. No such report is available in humans or in any other model systems during aging.     

应激对大鼠心肌硫氧还蛋白还原酶表达的影响

目的 探讨硫氧还蛋白还原酶在大鼠心肌抗氧化应激反应中的作用。方法 将Wistar大鼠冰泳5min，采用Northern blot和Western blot检测大鼠冰泳前后心肌硫氧还蛋白还原酶的表达情况。结果 应激后大鼠心肌中硫氧还蛋白还原酶的基因和蛋白表达均增加。结论 硫氧还蛋白还原酶增加有利于大鼠心肌对应激损伤的预防与修复。     

Effect of acute and chronic stress on testosterone secretion in male rats

The effect of acute and chronic stress on serum testosterone was studied in adult male Wistar rats. Acute noise-light stress and the presence of a dog, but not change of room, raised serum testosterone. This testosterone was of gonadal origin since noise-light stress did not increase serum testosterone in castrated rats. Chronic noise-light did not modify either testes weight or serum testosterone. This suggests that chronic stress did not necessarily lead to impairment of endocrine function of the testes in the rat.     

应激对大鼠心肌线粒体型硫氧还蛋白还原酶表达的影响

目的探讨线粒体型硫氧还蛋白还原酶（mitochondrial thioredoxin reductase，TR2）在大鼠心肌抗氧化应激反应中的作用。方法将Wistar雄性大鼠分成非应激组和应激组，应激组大鼠在处死前一天在冰水浴中泳动5min，采用Northern blot和Western blot检测大鼠心肌线粒体型硫氧还蛋白还原酶和蛋白的表达。结果应激组大鼠心肌中线粒体型硫氧还蛋白还原酶基因和蛋白表达均高于非应激组。结论线粒体型硫氧还蛋白还原酶基因和蛋白表达的增加有利于大鼠心肌抗氧化损伤。     

Preventive and curative effect of methanolic extract of Gardenia gummifera Linn. f. on thioacetamide induced oxidative stress in rats

ObjectiveTo evaluate the antioxidant and antihepatotoxic effect of methanolic extract of Gardenia gummifera Linn. f. root (MEGG) on thioacetamide (TAA) induced oxidative stress in male Wistar rats.MethodsIn the preventive study, rats were administered with 125 and 250 mg/kg of MEGG for 9 days prior to TAA administration (100 mg/kg s.c.). In post-treatment groups, rats were treated with MEGG at doses of 125 and 250 mg/kg, 2, 24 and 48 h after TAA intoxication. Silymarin was used as a standard drug control (100 mg/kg). Hepatotoxicity was assessed by quantifying the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). The antioxidant potential of MEGG was evaluated by the estimation of catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), reduced glutathione (GSH) and lipid peroxidation [thiobarbituric acid reactive substances (TBARS)] in hepatic and renal tissues. Histopathological changes were also evaluated.ResultsMEGG significantly (P≤0.05) prevented the elevation of serum AST, ALT, ALP, LDH and tissue malondialdehyde levels in both experimental groups, when compared to the TAA alone treated groups. The rats receiving TAA plus MEGG exhibited significant (P≤0.05) increases in hepatic and renal antioxidant activities including GSH, GST, GR, GPx and CAT levels. Quantification of histopathological changes also supported the dose dependent protective effects of MEGG.ConclusionsThese observations suggest that MEGG has dose dependent hepatoprotective and antioxidant effect against TAA induced oxidative stress.     

模拟失重对大鼠实验性胃溃疡氧化应激状态的影响

目的探讨模拟失重对乙酸诱导的大鼠实验性胃溃疡氧化应激状态的影响及可能机制。方法 32只SD大鼠随机分为4组,即尾部悬吊7 d组、尾部悬吊14 d组和相应的同步对照组。采用乙酸烧灼法制备大鼠慢性胃溃疡模型,造模后第3天悬吊组大鼠采用尾悬吊法建立模拟失重动物模型。游标卡尺检测胃溃疡面积,生化比色法测定大鼠血清中丙二醛(MDA)含量,超氧化物岐化酶(SOD)及谷胱甘肽过氧化物酶(GSH-Px)活性。结果与对照7 d组相比,悬吊7 d组大鼠溃疡面积显著增大(t=5.661,P<0.01);与对照14 d组比较,悬吊14 d组溃疡面积显著增大(t=4.233,P<0.01),血清MDA含量及SOD活性显著增高(t=2.641,P<0.05,t=5.758,P<0.01);与悬吊7 d组比较,悬吊14 d组溃疡面积显著减小(t=3.805,P<0.01),血清MDA含量及SOD活性显著增高。血清GSH-PX活性差异无统计学意义(P<0.05)。结论模拟失重可加重溃疡氧化应激反应,延迟溃疡愈合。     

改变血红素加氧酶-1水平对糖尿病大鼠氧化应激状态及肾功能的影响

目的 探讨血红素加氧酶-1(HO-1)对糖尿病(DM)大鼠氧化应激状态及肾功能的影响.方法 以链脲佐菌素诱导DM大鼠模型.SD大鼠分成4组:对照组、DM组、正铁血红素Hemin(HO-1)诱导剂组、ZnPP(HO-1抑制剂)组.检测血清总抗氧化能力(TAOC)、丙二醛(MDA)含量和尿白蛋白排泄率(UEA);RT-PCR法检测肾脏组织TNF-α和HO-1mRNA表达水平.结果 Hemin组血清总抗氧化能力与DM组相比明显增高;而给予ZnPP后DM大鼠MDA含量增加,总抗氧化能力降低;DM大鼠UEA上升(P均<0.01),并随病程延长而加重.Hemin组UEA与DM 5 w组相比已有下降趋势,但尚无统计学差异(P>0.05);ZnPP组大鼠UEA明显增高(P<0.01);与对照组相比,DM大鼠肾组织TNF-α及HO-1 mRNA表达增加;应用Hemin后DM大鼠肾脏组织TNF-α表达减少(P<0.01).结论提高DM大鼠肾脏HO-1表达水平可以改善肾组织氧化应激状态、延缓肾功能障碍.     

Effect of increased gastric mucosal histamine on alcohol-induced gastric damage in rats

The aim of this study was to determine whether the cytoprotective effect of prostaglandin might be mediated, at least in part, by inhibition of intramucosal histamine release. Intragastric instillation of increasing concentrations of ethanol in 150 mM HCl resulted in increasing lesion scores and increasing histamine release into the gastric content. Pretreatment with 16,16-dimethyl prostaglandin E2 significantly reduced both lesion scores and gastric histamine output. The intragastric instillation of histamine with tracer [14C]histamine either with or after 50% ethanol resulted in significant gastric tissue uptake of histamine and increased acid secretion. However this had no effect on lesion score, protein output or the protective effect of prostaglandin pretreatment. We conclude that the cytoprotective effect of 16,16-dimethyl prostaglandin E2 in the rat is independent of intramucosal histamine release.     

应激大鼠胃黏膜氧化应激指标受褪黑素影响的研究

目的探讨褪黑素干预应激大鼠胃黏膜氧化应激指标影响的研究.方法采用浸水-束缚(WIR)应激实验复制大鼠应激性溃疡模型.应激前30 min,MT(melatonin)5、20mg·kg-1和应激组大鼠分别腹腔注射MT 5、20mg·kg-1和等体积生理盐水.应激6h后,观察各组大鼠胃黏膜病变情况,对溃疡指数(UI)进行评分,同时检测各组大鼠胃黏膜内丙二醛(MDA)含量、胃黏膜超氧化物歧化酶(SOD)活性和还原型谷胱甘肽(GSH)水平.结果WIR应激6h后,应激组大鼠胃黏膜MDA水平显著高于对照组(P＜0.01).MT 5、20mg·kg-1组较应激组MDA水平显著下降(P＜0.01),且MT 20mg·kg-1组显著低于MT 5mg·kg-1组(P＜0.01).应激组大鼠SOD、GSH活性较对照组明显降低(P＜0.01),MT 5、20mg·kg-1组较应激组SOD、GSH活性有升高趋势.比较各组UI发现,MT 5、20mg·kg-1组UI显著低于应激组(P＜0.01),其中MT 20mg·kg-1组UI显著低于MT 5mg·kg-1组(P＜0.05).结论褪黑素通过其抗氧化的作用对应激大鼠胃黏膜损伤起保护作用.     

芒果苷对缺氧缺血性脑损伤大鼠氧化应激反应及神经细胞凋亡的影响

目的研究芒果苷通过PI3K/Akt/mTOR途径对缺氧缺血性脑损伤大鼠的氧化应激反应及神经细胞凋亡的影响。方法将144只SD新生大鼠按随机原则分为6组,空白对照组、模型组、阳性对照组、芒果苷低剂量组、芒果苷中剂量组和芒果苷高剂量组,每组24只。除空白对照组外其他各组复制缺氧缺血性脑损伤大鼠模型,造模后空白对照组和模型组给予等体积的生理盐水,阳性对照组给予尼莫地平[0.4 mg/(kg·d)],芒果苷低、中、高剂量组分别给予芒果苷50、100、200 mg/(kg·d),连续给药4周。检测各组大鼠神经功能损伤评分;干湿重法检测各组大鼠脑组织含水量;HE染色观察大鼠脑组织的病理形态学改变;原位细胞凋亡检测(TUNEL)大鼠脑组织神经元凋亡情况;生化检测法测定脑组织中超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)和总抗氧化能力(T-AOC)活力;采用实时荧光定量PCR(Real-time PCR)测定大鼠脑组织内PI3K/Akt/mTOR mRNA表达;运用蛋白免疫印迹法(Western blot)检测脑组织中Caspase-3、Bcl-2、Bcl-xL、Bad、Bax蛋白含量。结果模型组大鼠的神经损伤评分、脑组织含水量、神经细胞凋亡数、MDA含量、PI3K表达及Caspase-3含量显著高于空白对照组,完整的神经元数量及脑组织中SOD、GSH-Px、T-AOC含量、Akt、mTOR表达及Bcl-2、Bcl-xL、Bad含量显著低于空白对照组(P0.01);各药物组大鼠的神经损伤评分、脑组织含水量、神经细胞凋亡数、MDA含量、PI3K表达及Caspase-3含量显著低于模型组,完整的神经元数量及脑组织中SOD、GSH-Px、T-AOC含量、Akt、mTOR表达及Bcl-2、Bcl-xL、Bad含量显著高于模型组(P0.01)。结论芒果苷通过下调Caspase-3的表达、上调Bcl-2和Bcl-xL的表达,增强PI3K/Akt/mTOR通路的表达来增强神经保护作用,抑制神经细胞凋亡,提高神经细胞存活率。     

Effect of atorvastatin on serum oxidative stress and N-terminal brain natriuretic peptide expression in rats

Objective:To investigate the effect of atorvastatin on serum oxidative stress and N-terminal brain natriuretic peptide expression in rats.Methods:A total of 40 healthy male SD rats were randomly divided into the sham group(Croup A,n=10,saline 5 mL/d),ischemia-reperfusion group(Group B,n=10,saline S mL/d),atorvastatin group(Group C,n=10.atorvastatin 20 mg/kg·d),atorvastatin + N-amino-arginine group(Group D,n=10,atorvastatin 20 mg/kg·d + N-amino arginine 15 mg/kg).Myocardial ischemia-reperfusion rat model was eslablished after 3 days of gavage.N-amino arginine 15 mg/kg was given by tail vein injection 15 min before ischemia.After reperfusion,enzymology indicators such us creatine kinase(CK) and lactate dehydrogenase and the oxidative stress parameters such as nitric oxide(NO),malondialdehyde(MDA) and total superoxide dismutase(TSOD),and n-terminal pro-brain natriuretic peptide(NT-proBNP)expression was detected by immunohistochemistry.Results:LDH and CK levels of group A were significantly lower than the outer three groups,and group B was the highest.There was significant difference between group B and group C(P0.05),and no significant difference between group B and group D(P0.05).MDA levels in group B were significantly higher than the other three groups.The lowest was group A,followed by group C,the difference among groups was significantly(P0.05).TSOD and NO levels in group B was the lowest,the level in group A was the highest,followed by group C,the difference among groups was significant(P0.05).NT-proBNP level in group B was significantly higher than the other three groups,the lowest was group A,followed by group C,the difference among groups was significant(P0.05).Conclusions:Atorvastatin has a protective effect on the myocardial injury in the myocardial ischemia and reperfusion rats.It can increase NO synthesis and decrease MDA content,increase serum TSOD activity and the oxidative stress effect,meanwhile protect myocardial cells and reduce myocardial injury.