营养缺乏与脂质过氧化的关系

人体必需的营养素如含硫氨基酸、维生素A、B_2、C、E、辅酶Q等以及微量元素铜、锌、锰、硒等均有抗氧化作用;果糖能加重脂质过氧化作用,葡萄糖或淀粉则有减轻脂质过氧化作用。这些抗氧化营养素缺乏时,机体抗氧化能力下降,多不饱和脂肪酸发生脂质过氧化而导致组织、细胞等损害。因此,在治疗这些营养缺乏病时,不仅要补给所缺乏的营养素,而且还要给予其他抗氧化剂,以协同作用,取得较好的治疗效果。     

脂质过氧化与癌肿形成

脂质过氧化与癌肿形成许小波（浙江医科大学医学系,杭州３１０００３）关键词脂质过氧化,癌肿形成自从１９５４年Ｈｏｒｇｅｒ和Ｐｈｉｌｐｏｔ认识到生物脂质过氧化和自由基形成在细胞膜损伤中的可能重要作用后,其在生化、营养、药理等各个领域都得到了广泛而深入的研...     

人参皂甙对急性肾衰大鼠抗脂质过氧化的作用

我们最近观察到早期注射人参皂甙可改善初发期急性肾衰大鼠的肾功能,减轻并促进修复肾脏病变。鉴于肌注甘油引起急性肾衰的机制,可能有肾缺血的作用存在,而缺血组织的微循环障碍,可生成脂质过氧化物而导致组织损伤。邓惠玲和张均田报道人参皂甙能抑制大鼠肝脏和脑微粒...     

红葡萄酒对大鼠肝脏抗氧化酶和脂质过氧化的影响

选用雄性SD大鼠,分别灌胃红葡萄酒、酒精及水。实验90 d中每隔30 d处死一批动物,测定大鼠肝脏匀浆组织中的超氧化物歧化酶(Superoxide dismutase SOD)、过氧化氢酶(Catalase CAT)、谷胱甘肽过氧化物酶(Glutathione peroxidase GSH-Px)活性和脂质过氧化产物丙二醛(Malondialdehyde MDA)含量变化。观察摄入红葡萄酒后大鼠肝脏抗氧化酶活性变化及对肝脏脂质过氧化的影响。结果表明,红葡萄酒能提高SOD活性,且SOD活性与灌胃时间、剂量有一定关系;长期红葡萄酒和酒精摄入可诱导CAT活性增强,加剧肝脏的脂质过氧化(LPO)作用;红葡萄酒组、酒精组0.63、1.25 g/kg剂量GSH-Px活性均明显升高(P<0.05),酒精组1.88 g/kg剂量有极显著性差异(P<0.01);试验初期,红葡萄酒大剂量显著降低肝脏中MDA的含量。试验中期,红葡萄酒中大剂量显著降低MDA含量。试验末期,红葡萄酒大剂量和酒精中大剂量显著升高肝脏中MDA含量。     

丹参酮对心肌肌质网脂质过氧化过程中脂类自由基的清除作用

应用自旋捕集方法和化学发光方法研究天然抗氧化剂丹参酮（Ｔａｎｓｈｉｎｏｎｅ）对心肌肌质网膜脂质过氧化过程中产生的脂类自由基的清除作用。发现在一定的浓度范围内,丹参酮对脂质过氧化有较好的保护作用,在丹参酮浓度大于１ｍｇ／ｍｇ蛋白时,对脂类自由基清除率可达６０％。丹参酮对肌质网膜脂质过氧化的保护机理可能是通过清除脂类自由基而阻断脂质过氧化的链式反应,而不是清除氧自由基而防止脂质过氧化的启动。     

改良硫代巴比妥酸荧光法测定血清过氧化脂质

对目前使用的过氧化脂质（LPO）硫代巴比妥酸（TBA）荧光测定法进行了改进．血清样本在冰醋酸存在的条件下,100℃水解60min,LPO释放的雨二醛（MDA）与TBA形成复合物,用甲醇沉淀血清蛋白质并减少非特异性干扰,以λ_ex＝515nm、λ_em＝550ｎｍ测定MDA－TBA复合物的荧光强度．此法操作简便、快速,结果准确,荧光稳定．LPO含量（以MDA表示）在0～20μmol／L与荧光强度呈线性关系（r＝0．9994）,最低检测限为0．16μmol／L,回收率为105．08％,重复性CV＝4．23％．     

生物系统中脂质过氧化检测方法的评述

生物体系中脂质过氧化的检测方法是脂质过氧化反应机理研究能否取得成功的关键因素之一.检测生物体系中脂质过氧化的方法有多种,但各种检测方法在不同的实验中都显示出一定的优缺点,近年来应用较多并且很有前途的实验方法是高压液相色谱法以及化学发光法等.     

脂质过氧化对细胞衰老的延缓作用（Ⅱ）

本文以传代培养的人胚肺成纤维细胞为研究对象,以Ｆｅ＾２＋／维生素Ｃ为诱发脂质过氧化的体系,研究了脂质过氧化对细胞衰老的影响。结果表明适当低水平的脂质过氧化可以明显改善细胞形态,延缓细胞退变性形态特征的出现;并使细胞存活期延长２－８天。随着细胞传代数的增加,对照组和处理组细胞中超氧物歧化酶活力下降,但处理细胞中ＳＯＤ活力并不高于对照组,说明ＳＯＤ至少在某些情况下对延缓细胞衰老并不起主要作用。     

Role of Pinoline and Melatonin in Stabilizing Hepatic Microsomal Membranes against Oxidative Stress

We investigated the influence of pinoline (0.01–1.5 mM) on microsomal membrane fluiditybefore and after rigidity was induced by oxidative stress. In addition, we tested the effect ofpinoline in the presence of 1 mM melatonin. The fluidity in rat hepatic microsomes wasmonitored using fluorescence spectroscopy and it was compared to the inhibition ofmalonaldehyde (MDA) plus 4-hydroxyalkenals (4-HDA) production as a reflection of lipid peroxidation.Below 0.6 mM, pinoline inhibited membrane rigidity in a manner parallel to its inhibitoryeffect on MDA + 4–HDA formation. At concentrations between 1–1.5 mM, pinoline wasless effective in stabilizing microsomal membranes than was predicted from its inhibition oflipid peroxidation. The addition of 1 mM melatonin enhanced the membrane-stabilizing activityof pinoline (0.01–0.6 mM). This cooperative effect was not observed for concentrations ofpinoline between 1–1.5 mM. When pinoline was tested without induced oxidative damage,1–1.5 mM pinoline maintained membrane fluidity at the same level as that recorded afterinduced lipid peroxidation. The results suggest that pinoline may be another pineal moleculethat prevents membrane rigidity mediated by lipid peroxidation and this ability is enhancedby melatonin.     

The Antioxidative Effect of Fullerenes during the Peroxidation of Methyl Linoleate in Toluene

The antioxidative effect of fullerenes C₆₀ and C₇₀ was examined by measuring the inhibition of methyl linoleate (MeL) peroxidation in toluene initiated by 2,2′-azobis(2,4-dimethylvaleronitrile) (AMVN). The fullerenes retarded the formation of MeL hydroperoxides and lowered the rate of propagation. The reaction rates of fullerenes with AMVN-derived peroxyl radicals were much higher than that of MeL. These results indicate that fullerenes can act as retarders of lipid peroxidation, though their activity is low compared with that of α-tocopherol.     

Phosphorus Improves Arsenic Phytoremediation by Anadenanthera Peregrina by Alleviating Induced Oxidative Stress

Due to similarities in their chemical behaviors, studies examining interactions between arsenic (As)—in special arsenate—and phosphorus (P) are important for better understanding arsenate uptake, toxicity, and accumulation in plants. We evaluated the effects of phosphate addition on plant biomass and on arsenate and phosphate uptake by Anadenanthera peregrina, an important Brazilian savanna legume. Plants were grown for 35 days in substrates that received combinations of 0, 10, 50, and 100 mg kg^?1 arsenate and 0, 200, and 400 mg kg^?1 phosphate. The addition of P increased the arsenic-phytoremediation capacity of A. peregrina by increasing As accumulation, while also alleviating As-induced oxidative stress. Arsenate phytotoxicity in A. peregrina is due to lipid peroxidation, but not hydrogen peroxide accumulation. Added P also increased the activity of important reactive oxygen species-scavenging enzymes (catalase and ascorbate peroxidase) that help prevent lipid peroxidation in leaves. Our findings suggest that applying P represents a feasible strategy for more efficient As phytoremediation using A. peregrina.     

Expression of antioxidant enzymes in rat kidney during ischemia-reperfusion injury

The effect of ischemia-reperfusion on activity, protein and m-RNA levels of catalase, copper-zinc and manganese containing superoxide dismutases and glutathione peroxidase, the enzymes that are involved in free radical detoxification was studied in rat kidney. Ischemia alone did not alter either the activities or protein levels of superoxide dismutase and glutathione peroxidase. However, catalase activity was found to be inhibited to 82% of control. The inhibition of catalase was due to the inactivation of the enzyme as there was no significant change in enzyme protein level. Reperfusion following ischemia, however, led to a significant decrease in both the activities as well as the protein levels of all the antioxidant enzymes. The observed overall decrease in total superoxide dismutase activity was the net effect of a decrease in copper-zinc superoxide dismutase while manganese superoxide dismutase activity was found to be increased following reperfusion. This observed increased manganese superoxide dismutase activity was the result of its increased protein level. The mRNA levels for catalase, superoxide dismutases, and glutathione peroxidase were observed to be increased (100–145% of controls) following ischemia; reperfusion of ischemic kidneys, however, resulted in a significant decrease in the levels of mRNAs coding for all the enzymes except manganese superoxide dismutase which remained high. These results suggest that in tissue, the down regulation of the antioxidant enzyme system could be responsible for the pathophysiology of ischemia-reperfusion injury.     

氮肥、钙肥和盐处理在冬小麦融冻胁迫适应中的生理调控作用

采用盆栽法种植冬小麦(烟农19号),在出苗7d后分别用氮肥(60mmol/L NH4CO3)、钙肥(100 mmol/L CaCl2)和NaCl(100 mmol/L)处理,生长30 d后开始冻融处理(15℃,0℃,-15℃,0℃,15℃各处理3h).结果表明,在融冻和冻融胁迫过程中冬小麦叶片细胞膜透性变化和膜脂过氧化程度与温度变化呈显著负相关(R=-0.89**,R=-0.85**).与对照相比,经氮肥、钙肥和盐处理的冬小麦叶片细胞膜透性和丙二醛含量较低,而SOD、CAT和POD活力均较高,这表明施肥能降低细胞膜脂过氧化作用,提高细胞膜抗氧化能力.但不同肥料和盐处理在冬小麦融冻胁迫中对渗透调节物质的调节作用存在差异.施氮肥使冬小麦叶片脯氨酸和可溶性蛋白质含量分别高于对照44.3％和23.6％,可溶性糖含量低于对照(-17.3％);而钙肥和盐处理却使冬小麦叶片可溶性糖含量高于对照(57.5％和37.1％).研究表明,氮肥通过调节氮代谢提高脯氨酸和蛋白质含量,钙肥通过促进糖代谢提高可溶性糖含量.因此,冬季给冬小麦幼苗施一定的混合肥,不仅可促使植物细胞积累较多的渗透调节物质防止细胞结冰,激活体内保护酶系统防止细胞膜脂过氧化,而且施肥还可促使来年春季幼苗的快速返青健壮生长.通过合理施肥改善植物的代谢提高作物的抗融冻能力,这可能是目前投资少,见效快的有效途径.     

Lipid peroxide induced DNA damage: protection by turmeric (Curcuma longa)

Summary Liposomal lipid peroxidation and peroxide induced DNA damage were investigated. Inhibition of lipid peroxidation was studied using 400 µM uric acid, -carotene, -tocopherol, curcumin and butylated hydroxyanisole (BHA). Curcumin, the active principle of turmeric (Curcuma longa), was as effective an antioxidant as BHA. An aqueous extract of turmeric was also found to be an effective inhibitor. The inhibition obtained using this aqueous extract, incorporated into the liposome itself, was 70% at 300 ng/µ1 This indicates the presence of yet another antioxidant in turmeric besides the lipophilic curcumin. The aqueous antioxidant extended 80% protection to DNA against peroxidative injury at 100 ng/µl. This component of turmeric is being characterised and investigated as an antioxidant/anticlastogen and as an antipromoter.Abbreviations GT₁b Trisialoganglioside - TBS Tris Buffered Saline - PBS Phosphate Buffered Saline - TBA Thio Barbituric acid - BHA Butylated Hydroxy Anisole - EDTA Ethylene Diamine Tetra Acetic Acid     

Effect of cadmium on lipid peroxidation and activities of antioxidant enzymes in growing pigs

Malondialdehyde (MDA), glutathione (GSH) content, total antioxidant capacity (T-AOC) levels, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione transferase (GST) activities were studied in serum, liver, and kidney of growing pigs after graded doses of cadmium administration in diets. One hundred ninety-two barrows (Duroc x Landrace x Yorkshire), with similar initial body weight 27.67±1.33 kg, were randomly allotted into 4 different treatments with 3 replications (16 pigs per replication). The treatments received the same basal diet added with 0, 0.5, 5.0, and 10.0 mg/kg cadmium (as CdCl₂), respectively. The results showed pigs treated with 10 mg/kg cadmium significantly decreased average daily gain (ADG) (p<0.05) and increased feed/gain ratio (F/G) (p<0.05) compared to the control. In this treatment, the contents of MDA increased significantly (p<0.05), GSH concentrations, T-AOC levels, and the activities of SOD, GSH-PX, and GST decreased significantly (p<0.05). The results indicate 10 mg/kg cadmium could decrease pig antioxidant capacity after extended exposure and cadmium-induced increase lipid peroxidation might not be only the result of the possibility of lower level of GSH but could also be as a result of direct action of cadmium on peroxidation reaction.     

冬季融冻过程中白三叶叶片抗氧化酶活力和渗透调节物含量变化与抗冻性的关系

入冬气温大幅变化引起的冻融既是抗冻植物抗冻力形成的重要阶段也是非抗冻植物大量死亡的主要原因,但是抗冻植物为何能在冬季融冻条件下生存的生理机理尚不清楚。以生长在烟台地区抗冻白三叶(Trifolium repens)为材料,分析研究了不同微生态环境下生长的白三叶在冬季融冻过程中叶片抗氧化物酶活性、渗透调节物含量、丙二醛和细胞膜透性的变化,以了解它们在白三叶抗冻中的作用。结果表明:在气温突然下降至零度以下(融-冻阶段),三样地白三叶叶片冻结,叶片细胞膜透性在经历短暂下降后迅速急剧增加2倍,MDA含量增加85%,叶片中脯氨酸和蛋白质含量、抗氧化酶(过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD))活力增加。在气温上升至日均温零度以上(冻-融阶段), 叶片开始融化,白三叶叶片膜透性、丙二醛和脯氨酸含量、POD和CAT活力先增加后降低,SOD活力和蛋白质含量持续增加。由此可见,快速增强的抗氧化物酶活力和快速增加的渗透调节物及时清除氧自由基防止细胞内膜脂过氧化保护了细胞膜的完整性而使细胞能在冷冻条件下生存,这可能是白三叶能在反复融冻过程中正常生长的重要生理机理。