Antioxidant activity ofcurculigo orchioides in carbon tetrachloride—induced hepatopathy in rats

In this study antioxidant activity of methanol extract of rhizomes ofCurculigo orchioides (MEC) was investigated using carbon tetrachloride (CCl₄)-intoxicated rat liver as the experimental model. The hepatotoxic rats were administered MEC for 90 days (daily, orally at the dose of 70 mg per kg body weight). Lipid peroxidation (LPO) in CCl₄-intoxicated rats was evidenced by a marked increment in the levels of thiobarbituric acid reactive substances (TBARS) and diene conjugates (CD), and also a distinct diminution in glutathione (GSH) content in the liver. In CCl₄+MEC—treated rats these biochemical parameters attained an almost normal level. The decreased activity of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GRD) in CCl₄—intoxicated rats, and its retrieval towards near normalcy in CCl₄+MEC—administered rats revealed the efficacy of MEC in combating oxidative stress due to hepatic damage. Elevated level of glutathione transferase(GTS) observed in hepatotoxic rats too showed signs of retuming towards normalcy in MEC co-administered animals, thus corroborating the antioxidant efficacy of MEC. The findings provide a rationale for further studies on isolation of active principles and its pharmacological evaluation.     

冷激诱导耐冷性过程中小麦幼苗抗氧化酶的变化

采用小麦幼苗为材料，研究了冷激诱导抗冷性过程中超氧化物歧化酶（SOD），过氧化氢酶（CAT），抗坏血酸专一性过氧化物酶（APX）、愈创木酚过氧化物酶（GPX）四种抗氧化酶活性的变化，结果发现冷激可以提高SOD，CAT，APX，GPX四种抗氧化酶的活性，表明冷激诱导的抗冷性与SOD，CAT，APX，GPX四种抗氧化酶活性增加有关，暗示SOD，CAT，APX，GPX四种抗氧化酶在冷激诱导小麦幼苗抗冷性的形成过程中起重要作用。     

纳米酶：结合天然酶和人工催化的力量

纳米酶代表了一类新型人工酶和生物催化剂,打破了无机与有机生命的界限。它既有纳米材料的理化特性,也有独特的类酶催化活性。同时,这些理化特性有可能会调控催化活性,使得纳米酶跟天然酶、传统的模拟酶和化学催化剂区别开来。纳米酶有比较好的稳定性、耐高温、低温、耐酸碱、活性可调且多功能,目前受到了广泛关注,在生物医药、环境治理、绿色农业、新能源等领域展现出巨大的应用前景,并初步形成了相应的学科框架。为了更好地推动纳米酶的发展,拓展对纳米酶的认识,文章回顾了纳米酶发现,分析凝练了纳米酶的学科特点及其结构,综述了纳米酶的应用,并展望了未来的发展趋势。     

Cd胁迫对水稻根际和非根际土壤酶活性的影响研究

通过根袋法盆栽实验,研究了重金属Cd胁迫对水稻根际和非根际土壤酶活性的影响。结果表明,随着Cd浓度的增加,根际和非根际土壤呼吸强度增加,但增幅变小,根际呼吸强度大于非根际且差异显著。在梯度浓度的Cd胁迫下,根际和非根际脲酶、蔗糖酶活性随Cd浓度增加均表现出先升后降的趋势;5mg kg-1施Cd处理,根际和非根际的脲酶、蔗糖酶活性最强,在Cd浓度为30mg kg-1时,根际和非根际土壤中蔗糖酶、过氧化氢酶、非根际脲酶活性受到抑制,但抑制率各不相同;三种酶在根际土壤中的活性普遍高于非根际土壤;土壤酶对Cd污染的敏感度依次为蔗糖酶＞脲酶＞过氧化氢酶,蔗糖酶、脲酶可作检测土壤Cd污染的指示酶。低浓度Cd刺激使根系更加活力旺盛,根系形态指标对Cd胁迫敏感顺序为：根尖数＞根体积＞根表面积＞根长＞平均直径。     

白灵菇多糖抗氧化性质的研究

对白灵菇子实体与茵丝体的多糖提取工艺及多糖抗氧化性质进行了研究.子实体多糖提取工艺为:超声波处理时间15 min,热水温度90 ℃,提取时间1.5 h,醇沉浓度60%.茵丝体多糖提取工艺为:超声波提取时间15 min,热水温度95℃,提取时间2 h,醇沉浓度80%.子实体与菌丝体粗多糖对氧自由基的清除活性均不高,对羟基自由基清除活性比较高,且随着浓度的增高,清除羟基自由基的能力不断上升,呈一定的剂量-效应关系.     

耐力训练及限食对老龄大鼠骨骼肌线粒体氧化及抗氧化水平影响的比较研究

目的:观察长期耐力训练及限食对老龄大鼠骨骼肌线粒体氧化及抗氧化水平的影响,比较其单独及协同作用,为"线粒体衰老"学说提供一定的理论依据。方法:32只17月龄雄性SD大鼠分为4组:安静组(Control,C)、限食组(Caloric-Restricted,CR)、运动组(Exercise,E)和限食加运动组(Caloric-restricted and Exercise,E+CR),训练方式为跑台运动,中等运动强度(64%VO2max,15m/min,60分钟/天,每周5天),限食摄入的标准为正常摄入组的60%,共训练及限食12周,相同月龄对照组正常饲养。12周后于末次训练后取大鼠骨骼肌分别进行线粒体氧化损伤水平及抗氧化水平测定。结果:CR组、E组和CR+E组骨骼肌线粒体丙二醛(malondialdehyde,MDA)含量显著降低,锰超氧化物歧化酶(manganese-containing superoxide dismutase,MnSOD)活性显著增加,谷胱甘肽过氧化物酶(glutathion peroxidase,GSH-PX)活性显著增加;E组和CR+E组骨骼肌线粒体过氧化氢酶(catalase,CAT)活性显著增加。结论:耐力训练提高机体的抗氧化水平,同时使细胞机能节省化,耗氧量相对下降而减少了自由基的产生,限食减弱了机体的氧化应激,减少了自由基的产生,阻止了脂质过氧化,同时限食动员了一系列的适应性的网络防御机制,增加了抗氧化水平,加强了防御。耐力运动在机体抗氧化能力上明显强于限食作用,而耐力运动与限食的协同作用对某些抗氧化酶的影响强于其单独作用的影响。     

Enzyme activity and myoglobin concentration in rat myocardium and skeletal muscles after passive intermittent simulated altitude exposure

Abstract

We studied the effect of intermittent hypobaric hypoxia exposure on lactate dehydrogenase and citrate synthase activities, together with myoglobin content, of rat myocardium, tibialis anterior, and diaphragm muscles. The intermittent hypoxia exposure programme consisted of daily 4-h sessions in a hypobaric chamber (5000 m) over a period of 22 days. Samples were taken at the end of the programme, and 20 and 40 days later, and compared with those of control animals. In myocardium, lactate dehydrogenase activity was significantly depressed in animals 20 days post-exposure (314.6 ± 15.3 IU · g^?1) compared with control animals (400 ± 14.3 IU · g^?1), while citrate synthase activity and myoglobin concentration showed a significant stepwise increase from control animals (88.2 ± 3.6 IU · g^?1 and 4.38 ± 0.13 μm · mg^?1) to animals 20 days (104.7 ± 3.7 IU · g^?1 and 5.01 ± 0.17 μm · mg^?1) and 40 days post-exposure (108.8 ± 6.5 IU · g^?1 and 5.11 ± 0.22 μm · mg^?1). In contrast, no differences were found in diaphragm and tibialis anterior muscles. Our results show that intermittent hypobaric hypoxia exposure increased the oxidative character of myocardium even 20 days after the hypoxic stimulus has ceased, and that this effect lasts for more than 40 days for citrate synthase activity and myoglobin concentration. These findings support our previous results on skeletal and cardiac muscle capillarization after passive intermittent simulated altitude exposure, thus providing morphofunctional and biochemical evidence for increased cardiac aerobic efficiency.     

Physical Activity as a Natural Antioxidant Booster and its Effect on a Healthy Life Span

Abstract

The recent Surgeon General's report (U.S. Department of Health and Human Services, 1996) promotes regular physical activity to enhance health. A possible mechanism by which physical activity contributes to a healthy life span is via enhanced antioxidant status. The purpose of this paper is to summarize findings from human studies on life span, health, antioxidants, and the effectiveness of physical activity as a natural antioxidant booster. Epidemiological studies concur that some antioxidants are inversely related to mortality. A single bout of exercise elevates some antioxidant enzyme and coenzyme activities. Regular physical activity enhances some antioxidants; however, strenuous exercise may diminish others. Results generally show that antioxidants play a mediating role in the way in which physical activity positively affects a healthy life span.     

Protective influence of vitamin E on the antioxidant defence system in the whole blood and liver of normal and alloxan-induced diabetic rats

The effect of oral administration of vitamin E for twenty-eight consecutive days on blood glucose, reduced glutathione levels, antioxidant enzymes (superoxide dismutase and catalase activities), and levels of malondialdehyde (as an index of free radical-mediated lipid peroxidation) was observed in the whole blood and liver of normal and alloxan-induced diabetic rats. It was found that oral administration of vitamin E significantly (p<0.05) lowered the blood glucose level and increased the body weight of the diabetic rats. The activities of superoxide dismutase and levels of reduced glutathione increased significantly (p<0.05) while the level of lipid peroxidation decreased.     

植物水分胁迫与活性氧保护酶

介绍了植物体活性氧酶促保护系统的组成及其对不同水分胁迫条件的响应，并对今后进一步的研究作出了展望。