Studies on Free Radical EPR,Superoxide Dismutase Water-soluble Lipidperoxide in Tears

By means of electron paramagnetic resonance(EPR), chemistry luminescence and fluorescent spectroscopy, the free radical, superoxide dismutase and water soluble lipid peroxide in tears of normal eyes(150 eyes, 100 cases), Moorens ulcer(9 eyes), coreal grafts rejection(16 eyes) were studied. The results showed that the spin density of the free radical was 36(±058)×1012 spins/mL tear, the content of the superoxide dismutase(SOD) was 384(±145) ng/mL tear, the opposite fluorescent density of the water soluble lipid peroxide was 12912(±1691) U/mL tear in normal tears. The normal values are 25—48×1012 spins/mL tear for free radical, 239—529 ng/mL tear for SOD, 9598—16225 U/mL tear for water soluble lipid peroxide. There are significant differences in different eyes, different sexes and different ages. The free radical and lipid peroxide are higher obviously in the tears of patients with Moorens ulcer and rejected corneal grafts, compared with those of the normal control subjects(P<001), SOD is lower evidently(P<001). The above fact shows the pathogenic mechanism of Moorens ulcer and keractoplasty rejection is significantly related to toxicities injuring effect of the free radical. These results have provided important experimental data for studying lacrimalogy and new methods for clinical diagnosis and treatrment.

Superoxide dismutase prevents development of adenocarcinoma in a rat model of Barrett's esophagus

AIM: To test whether antioxidant treatment could prevent the progression of Barrett's esophagus to adenocarcinoma.METHODS: In a rat model of gastroduodenoesophageal reflux by esophagojejunal anastomosis with gastric preservation, groups of 6-10 rats were randomized to receive treatment with superoxide dismutase (SOD) or vehicle and followed up for 4 mo. Rat's esophagus was assessed by histological analysis, superoxide anion and peroxinitrite generation, SOD levels and DNA oxidative damage.RESULTS: All rats undergoing esophagojejunostomy developed extensive esophageal mucosal ulceration and inflammation by mo 4. The process was associated with a progressive presence of intestinal metaplasia beyondthe anastomotic area (9% 1st mo and 50% 4th mo) (94% at the anastomotic level) and adenocarcinoma(11% 1st mo and 60% 4th mo). These changes were associated with superoxide anion and peroxinitrite mucosal generation, an early and significant increase of DNA oxidative damage and a significant decrease in SOD levels (P＜0.05). Exogenous administration of SOD decreased mucosal superoxide levels, increased mucosal SOD levels and reduced the risk of developing intestinal metaplasia beyond the anastomotic area (odds ratio = 0.326; 95%CI: 0.108-0.981; P = 0.046),and esophageal adenocarcinoma (odds ratio = 0.243;95%CI: 0.073-0.804; P = 0.021).CONCLUSION: Superoxide dismutase prevents the progression of esophagitis to Barrett's esophagus and adenocarcinoma in this rat model of gastrointestinal reflux, supporting a role of antioxidants in the chemoprevention of esophageal adenocarcinoma.

Effect of superoxide dismutase and malondialdehyde metabolic changes on carcinogenesis of gastric carcinoma

AIM: To investigate the relationship between the superoxide dismutase (SOD), malondialdehyde (MDA)metabolic changes and the gastric carcinogenesis.METHODS: The SOD activity and MDA content were measured in the gastric tissues from the focus center,peripheral and far-end areas of gastric carcinoma (n = 52)and gastric ulcer (n = 10). All the tissues were subjected to routine histological examinations and classifications.RESULTS: The SOD activity was greatly reduced but the MDA content was markedly increased in the center areas of the non-mucous gastric carcinoma (non-MGC); and the poorly differentiated gastric carcinoma varied. The SOD activity was gradually decreased and the MDA content was gradually increased in the tissues from the focus far-end, peripheral to center areas of non-MGC. Both of the SOD activity and the MDA content were significantly declined and were respectively at same low level in the tissues from the focus center, peripheral, and far-end area with the mucous gastric carcinoma (MGC). In contrast to the gastric ulcer and grade Ⅰ or Ⅱ of non-MGC, the same level of the SOD activity and the MDA content were found in the focus center areas. Between non-lvlGC (groups A-D) and gastric ulcer (group F), the differences of SOD activity and MDA content were very noticeable in the gastric tissues from the focus peripheral and far-end areas, in which the SOD activity showed noticeable increase and the MDA content showed noticeable decrease in the gastric ulcer.CONCLUSION: The active free radical reaction in the gastric tissues can induce the carcinogenesis of non-MGC.The utmost low ability of antioxidation in the gastric tissues can induce the carcinogenesis of MGC. The metabolic change of the free radicals centralized mostly in the center of ulcerated lesions only, which suggested the ability of antioxidation was declined only in these lesions. However,the metabolism of free radicals varied significantly and the ability of antioxidation declined not only in the local focus area but also in the abroad gastric tissues with gastric carcinoma.

Effects of leukemia inhibitory factor and basic fibroblast growth factor on free radicals and endogenous stem cell proliferation in a mouse model of cerebral infarction

The present study established a mouse model of cerebral infarction by middle cerebral artery occlusion, and monitored the effect of 25 tJg/kg leukemia inhibitory factor and （or） basic fibroblast growth factor administration 2 hours after model establishment. Results showed that following administration, the number of endogenous neural stem cells in the infarct area significantly increased, malondialdehyde content in brain tissue homogenates significantly decreased, nitric oxide content, glutathione peroxidase and superoxide dismutase activity significantly elevated, and mouse motor function significantly improved as confirmed by the rotarod and bar grab tests. In particular, the effect of leukemia inhibitory factor in combination with basic fibroblast growth factor was the most significant. Results indicate that leukemia inhibitory factor and basic fibroblast growth factor can improve the microenvironment after cerebral infarction by altering free radical levels, improving the quantity of endogenous neural stem cells, and promoting neurological function of mice with cerebral infarction.

Traditional Chinese medicine “Qing Yi Tang” alleviates oxygen free radical injury in acute necrotizing pancreatitis

ＴｒａｄｉｔｉｏｎａｌＣｈｉｎｅｓｅｍｅｄｉｃｉｎｅ“ＱｉｎｇＹｉＴａｎｇ”ａｌｅｖｉａｔｅｓｏｘｙｇｅｎｆｒｅｅｒａｄｉｃａｌｉｎｊｕｒｙｉｎａｃｕｔｅｎｅｃｒｏｔｉｚｉｎｇｐａｎｃｒｅａｔｉｔｉｓＬＩＺｈａｎＬｉａｎｇ１，ＷＵＣｈｅｎｇＴａｎ...

Effects of Longyanshen polysaccharides on free radical metabolism in senescence accelerated-prone mice

BACKGROUND： Along with aging, antioxidase activity decreases and oxygen-derived free radicals greatly accumulate, resulting in cellular senescence, or even cell death. This is manifested by hypomnesia and disordered metabolism of free radicals. Studies have reported that Longyanshen polysaccharides have the function of antioxidation and improved brain memory. OBJECTIVE： To observe the effects of Longyanshen polysaccharides on free radical metabolism in brain tissue to verify the anti-aging mechanisms in senescence accelerated-prone （SAMP8） mice. DESIGN, TIME AND SETTING： The randomized, controlled, biochemical experiment was performed in the Department of Pharmacology and Scientific Experimental Center of Guangxi Medical University （China） from September 2005 to January 2008. MATERIALS： Forty SAMP8 mice were randomized into four groups： SAMP8 control group, as well as low-, mid-, and high-dose polysaccharide, with 10 mice in each group. Ten senescence accelerated-resistantprone （SAMR 1） mice served as the normal control group. Longyanshen polysaccharides, extracted from the medical plant Longyanshen, were supplied by the Department of Pharmacology, Guangxi Medical University Superoxide dismutase （SOD）, glutathione peroxidase （GSH-Px）, malonaldehyde （MDA）, nitric oxide （NO）, and total protein test kitwere purchased from Nanjing Jiancheng Bioengineering Institute （China）. METHODS： SAMP8 mice were used to establish a dementia animal model. SAMP8 and SAMR1 control mice were administered 30 mL/kg saline. The low-, middle-, and high-dose polysaccharide groups were administered 45, 90, and 180 mg/kg Longyanshen polysaccharides, respectively. Each group was treated by intragastric administration, once daily, for 50 continuous days. MAIN OUTCOME MEASURES： One hour after the last administration, mouse brain tissues were collected, and retro orbital blood sampling was performed. Spectrophotometry was used to measure SOD and GSH-Px activity, as well as MDA and NO concentration in sera and brains of SAMP8 mice. RESULTS： SOD and GSH-Px activity decreased significantly, and MDA and NO concentration increased significantly, in SAMP8 control group brain tissues, compared with the SAMP1 control group （P 〈 0.05）. Compared with the SAMP8 control group, Longyanshen polysaccharide-treated groups exhibited enhanced SOD and GSH-Px activity, as well as decreased MDA and NO concentration, in serum and brain tissue （P 〈 0.05）. Longyanshen polysaccharides exerted a similar effect on SOD, GSH-Px, MDA, and NO concentrations in serum and brain tissues of SAMP8 mice. CONCLUSION： Longyanshen polysaccharides scavenged free radicals effectively, reduced NO concentration and ameliorated NO toxicity, thereby influenced aging and stress, as well as improving memory capacity in the brain.

Effects of transection of cervical sympathetic trunk on cerebral infarct volume and oxygen free radical levels in rats with focal cerebral ischemia/reperfusion injury

BACKGROUND： Stellate ganglion block （SGB） plays a protective role on the brain, but the precise mechanism of action is not clear. OBJECTIVE： To simulate SGB by transection of the cervical sympathetic trunk （TCST） and to investigate the TCST effects on changes in cerebral infarct volume and oxygen free radical levels in rats with focal cerebral ischemia/reperfusion injury. DESIGN, TIME AND SETTING： A complete randomized control animal experiment was performed at the Institute of Neurological Diseases of Taihe Hospital, Yunyang Medical College from February to December 2005. MATERIALS： A total of 101 healthy Wistar rats, weighing 280-320 g, of both genders, aged 17-18 weeks, were used in this study. 2, 3, 5-triphenyltetrazolium chloride （TTC） was purchased from Changsha Hongyuan Biological Company. Superoxide dismutase （SOD）, malondialdehyde （MDA） and nitric oxide （NO） assay kits were provided by Nanjing Jiancheng Bioengineering Institute. METHODS： Rats were randomly divided into a TCST group, a model group and a sham operation group. Successful models were included in the final analysis, with at least 20 rats in each group. After TCST, rat models of focal cerebral ischemia/reperfusion injury were established in the TCST group by receiving middle cerebral artery occlusion （MCAO） by the intraluminal suture method for 2 hours, followed by 24 hours of reperfusion. Rat models of focal cerebral ischemia/reperfusion injury were made in the model group. Rats in the sham operation group underwent experimental procedures as for the model group, threading depth of 10 mm, and middle cerebral artery was not ligated. MAIN OUTCOME MEASURES： Brain tissue sections of ten rats from each group were used to measure cerebral infarct volume by TTC staining. Brain tissue homogenate of another ten rats from each group was used to detect SOD activities, MDA contents and NO levels. Rat neurological function was assessed by neurobehavioral measures. RESULTS： Cerebral infarct volume was bigger in the model group than in the TCST group （P 〈 0.05）. Twenty four hours after cerebral ischemia/reperfusion, SOD activities were lower, whereas MDA contents and NO levels were higher in the TCST and model groups, compared with the sham operation group （P 〈 0.05 or P 〈 0.01）. Compared with the model group, SOD activities were higher, whereas MDA contents and NO levels were lower in the TCST group （P 〈 0.05）. CONCLUSION： After TCST, cerebral infarct volume is reduced, SOD activities are increased, and MDA contents and NO levels are decreased compared to the model group in rats with focal cerebral ischemia/reperfusion injury. These changes may be associated with TCST.

Effect of Acupuncture on Free Radicals in Rats with Early Experimental Spinal Cord Injury

Effect of acupuncture on free radicals after spinal cord injury was observed in rats with experimental spinal cord injury (SCI). Results indicated that within 24 hours after SCI malondialdehyde (MDA) increased progressively, 2 hours after SCI it reached the peak; and the superoxide dismutase (SOD) activity decreased significantly at the same hours, the decrease being the most marked 2-6 hours after SCI. The MDA content in the acupuncture group was significantly lower (P<0.05) and the SOD activity higher (P<0.01) than that of the control group respectively. It is suggested that acupuncture inhibits production of MDA and increases the SOD activity.……

Superoxide-like Cu/GO single-atom catalysts nanozyme with high specificity and activity for removing superoxide free radicals

Although nanozyme has become an emerging area of research attracting extensive attention recently,the activity and specificity of currently reported nanozymes are generally lower than those of natural enzymes.Developing highly active and specific nanozymes is therefore extremely necessary and also remains a great challenge.Superoxide dismutase(SOD)catalyzes the disproportionation of cytotoxic O_(2)·^(−)into hydrogen peroxide and oxygen,and plays an important role in reducing human oxidative stress.In this work,we prepare Cu single-atom catalysts(Cu/GO SACs,GO=graphene oxide)through a simple and low-cost strategy at room temperature using Cu foam and graphene oxide.Cu/GO SACs can maintain excellent catalytic activity under harsh environment.Compared with the natural enzyme,SOD-like Cu/GO SAC nanozyme has higher catalytic activity and meanwhile,it does not possess the common properties of other mimic enzymes often existing in nanomaterials.Based on the excellent SOD-like enzyme activity of Cu/GO SACs,it successfully eliminates the active oxygen in cigarette smoke.This work not only provides a new idea for the design and synthesis of nanozymes with excellent SOD mimetic properties,but also is promising in the treatment of lung injury and inflammatory diseases related to free radical production.

垂体后叶素性心肌缺血模型再探

本实验从自由基角度用垂体后叶素(Pit)性心肌缺血模型观察了小鼠心肌营养性血流(NBF),氧自由基(OFR)浓度,丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性的动态变化。结果表明;在Pit引起NBF显著降低的同时OFR浓度显著上升,MDA含量显著增加,SOD活性显著下降。提示Pit性心肌缺血模型有异常显著的自由基反应,这在抗心肌缺血损伤研究中为筛选某些氧自由清除剂提供了方便、廉价、在体的动物模型。

四逆汤对缺血心肌NBF,OFR浓度SOD活性及MDA含量的影响

从自由基角度在小鼠垂体后叶素(Pit)性心肌缺血模型上探讨了四逆汤保护缺血心肌的可能性,结果表明四逆汤显著降低缺血心肌的OFR浓度和MDA含量,显著增加心肌NBF和SOD活性,提示四逆汤可显著减少自由基损伤性因子,改善缺血心肌的灌流,增强自由基清除能力,该方剂可能对缺血心肌产生积极的保护作用。

渗透胁迫对花生幼叶活性氧伤害和膜脂过氧化作用的影响

对 3种不同抗旱性的花生栽培品种进行渗透胁迫处理。结果表明 :渗透胁迫使花生幼叶水势 ( ΨL)下降 ,花生幼叶的 O- 2 · 产生速率随渗透胁迫处理强度加大而增加 ,MDA含量以及 SOD、POD和 CAT的活性水平变化与 O- 2 · 产生速率的变化趋势相似。 MDA含量明显增高 ,其过程与水势呈负相关与 RPMP呈正相关 ,均达极显著水平。渗透胁迫处理过程中 ,GSH和 As A含量下降。与泉花 1 0号和汕油 71相比 ,白皮 1号 RPMP增加幅度、O- 2 · 产生速率和 MDA含量增加幅度都明显较小。SOD、POD和 CAT的活性水平下降较缓 ,GSH含量呈先增加后下降趋势 ,As A含量下降较慢。综合分析表明 ,白皮

脑损伤后脑组织自由基变化的实验研究

为了解脑损伤后自由基含量的变化及其与脑水肿之间的关系 ,将 4 2只SD大鼠分为正常组、假手术组、手术组 3组。采用黄嘌呤氧化酶法测定损伤灶周围脑组织匀浆中的超氧化物歧化酶 (SOD)活力 ,硫代巴比妥酸法测定丙二醛 (MDA)含量 ,双缩脲法测定组织蛋白 ,干湿法测定脑组织含水量。结果显示 ,假手术组与正常组比较无明显差异 ,颅脑损伤后损伤灶周围脑组织匀浆中SOD活力下降 ,72h达最低值 ,然后缓慢回升 ,但一直低于假手术组与正常组 (P <0 .0 5 ) ;脑组织匀浆中MDA的含量在伤后迅速上升 ,72h达最高值 ,后虽有下降 ,但一直处于较高水平。上述变化与假手术组和正常组比较有明显差异 (P <0 .0 5 )。大鼠脑损伤后损伤灶周围脑组织中SOD在 7d内持续降低 ,MDA持续升高 。

递增负荷运动至力竭大鼠肾脏自由基产生及氧化抗氧化能力的研究

以大鼠增负荷力竭性运动为模型，利用低温电子自旋共振（ＳＥＲ）技术，分别于安静时、运动中、运动后即刻、运动后３０ｍｉｎ、２ｈ、４ｈ、８ｈ提取大鼠肾组织，测定氧自由基（ＯＦＲ）信号强度，同时测定ＳＯＤ活力和ＭＤＡ含量，结果表明：①运动后恢复期３０ｍｉｎ，肾脏ＯＦＲ信号强度升高明显，提示运动性肾缺血及恢复期再灌注诱导的黄嘌呤氧化酶机制可能是肾组织ＯＦＲ生成的主要来源；②在运动过程中及恢复期ＯＦＲ改变与ＳＯＤ变化趋势基本吻合，提示肾内源性ＳＯＤ在防止ＯＦＲ损伤中起重要作用；③肾脏ＭＤＡ于运动后２ｈ出现峰值，而ＯＦＲ则于恢复期３０ｍｉｎ升至最高，说明除肾脏自身产生活性氧诱导脂质过氧化以外。

抗衰老口服液对自然衰老大鼠自由基的影响

目的:探讨中草药复方制剂抗衰老口服液(AOP)对自然衰老大鼠自由基的清除作用及其机制。方法:健康自然衰老Wistar大鼠(22月龄)40只,分为5组:对照组,AOP低、中、高剂量组,青春宝抗衰老片(QCB)组。灌胃给药,每天1次,30 d后大鼠断头处死,取血,分离血浆;取心肌组织和脑组织,液氮冻存。检测血浆超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、丙二醛(MDA)、一氧化氮(NO),脑组织腺苷三磷酸酶(ATPE)以及心肌脂褐素的含量。结果:AOP中、高剂量组和QCB组大鼠血浆SOD含量、CAT含量、大脑皮层中ATP酶的含量均高于对照组(P<0.05);血浆NO含量、MDA含量、心肌脂褐质含量均低于对照组(P<0.05)。结论:中、高剂量AOP可减少自然衰老大鼠血浆自由基的产生、加速自由基的清除,促进脑组织能量代谢,具有抗衰老的生物学作用。

超氧化物歧化酶(SOD)的研究和应用进展

超氧化物歧化酶(SOD)是一类广泛存在于动物、植物、微生物中的金属酶,是化学生物界研究的热点之一。作为生物体内自由基的清洁剂,SOD对生物体(包括人体)具有重要的功能作用。

增龄对小鼠心肌氧自由基浓度、超氧化物歧化酶活性及丙二醛含量的影响

以心肌氧自由基(OFR)浓度、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量为指标,观察了增龄对心肌自由基反应的影响。结果表明:(1)心肌OFR浓度随增龄上升,至13、17月龄时达到显著水平(P<0.05):(2)心肌SOD活性随增龄下降,至13、17月龄时达到显著水平(P<0.05);(3)心肌MDA含量随增龄而增加,至13、17月龄时增加显著(P<0.05,P<0.01);(4)老年小鼠(17月龄)心肌SOD活性与OFR浓度呈高度显著的负相关关系(P<0.01),而MDA含量与OFR浓度呈显著的正相关关系(P<0.05)。上述结果表明,随增龄心肌自由基损伤性因素(OFR—MDA)增加,而保护性因素(SOD)减弱,这可能是老化心脏在结构、功能、代谢方面发生衰退的原因之一。

补阳还五汤治疗冠心病的临床研究及其作用机制探讨

１０２例冠心病（ＣＨＤ）患者随机分为中药补阳还五汤治疗组和西药对照组进行临床研究。结果：（１）补阳还五汤组患者血清脂质过氧化物（ＬＰＯ）、载脂蛋白Ｂ１００（ａｐｏＢ１００）水平及ＬＰ０／超氧化物歧化酶（ＳＯＤ）、ａｐｏＢ１００／ａｐｏＡ１比值明显降低，而血清ＳＯＤ、ａｐｏＡ１水平明显升高；（２）补阳还五汤缓解心绞痛的效果与对照组相似，但心电图改善优于对照组。提示补阳还五汤具有治疗ＣＨＤ的作用，抗脂质过氮化和调节载脂蛋白代谢可能是其重要的作用机制。

大鼠精索静脉曲张对睾丸氧自由基和LPO浓度的影响

应用成年Ｗｉｓｔａｒ大鼠制作精索静脉曲张动物模型，术后３月，处死动物取出睾丸。以电子自旋共振（ＥＳＲ）法测试睾丸组织的氧自由基相对自旋浓度，ＴＢＡ法和化学发光法分别检测过氧化脂质（ＬＰＯ）含量、超氧化物歧化酶（ＳＯＤ）水平。实验结果表明，精索静脉曲张组（ＶＧ）左、右睾丸氧自由基自旋浓度明显高于假手术对照组（ＣＧ）（Ｐ＜Ｏ．０５）；ＶＧ双睾ＬＰＯ含量显著高于ＣＧ（Ｐ＜０．０１）；睾丸氧自由基相对自旋浓度和ＬＰＯ含量呈明显正相关（ｒ＝０．５４，Ｐ＜０．０５）；．ＶＧ双睾ＳＯＤ水平均显著低于ＣＧ（Ｐ＜０．０１）；睾丸ＳＯＤ水平与氧自由基自旋浓度呈显著负相关（ｒ＝－０．９１，Ｐ＜０．０１）。上述结果提示：精索静脉曲张大鼠睾丸组织中含有大量的氧自由基和ＬＰＯ，损伤睾丸细胞及其各级生物膜，会导致睾丸生精功能紊乱造成不育，而睾丸氧自由基清除障碍可能是氧自由基浓度增高继之ＬＰＯ含量增多的重要机制之一。

急性CO中毒患者血清SOD、GSH-Px活性及MDA水平的变化及其意义

目的 探讨急性一氧化碳中毒 (ACOP)患者血清丙二醛 (MDA)水平、谷胱甘肽过氧化物酶 (GSH -Px)及超氧化物歧化酶 (SOD)活性的变化 ,了解ACOP时自由基氧化损伤在其病理机制中的作用。方法 选择不同中毒程度的ACOP患者70例 ,分别于入院即刻、12、2 4、4 8、72h抽血测定血清中MDA水平及SOD、GSH -Px的活性。结果 ACOP时 ,中度CO中毒组与轻度中毒组比较 ,血清MDA水平升高 ,但不具有显著性意义 (P >0 0 5 ) ;重度中毒组与中度中毒组比较 ,MDA水平显著性升高 (P <0 0 5 ) ,且 2 4、4 8h仍维持在较高水平。中度中毒组与轻度中毒组比较 ,血清SOD及GSH -Px活性水平降低 ,但不具有显著性意义 (P >0 0 5 ) ;重度中毒组与中度中毒组比较 ,SOD及GSH -Px活性水平显著性降低 (P <0 0 5 )。结论 ACOP时血清MDA水平升高 ,SOD及GSH -Px活性降低 ,提示ACOP时存在着严重自由基氧化损伤的病理过程 ,为ACOP治疗过程中抗氧化治疗提供了依据。同时 ,血清MDA水平和SOD及GSH -Px活性也可作为中毒损伤程度评估、预后判定的指标之一。