维生素E、牛黄酸等抗氧化剂对博莱霉素致突变性的拮抗作用

目的观察抗氧化剂(维生素E、牛黄酸、二甲亚砜和维生素C)针对博莱霉素(Bleomycin,BLM)的拮抗作用.方法在人外周血淋巴细胞培养物中注入一定剂量的BLM并一定剂量的抗氧化剂,然后观察淋巴细胞的姐妹染色单体交换率(sister chromatid exchanges,SCE rate)的变化.结果维生素E浓度为5μl/ml时,可显著地拮抗BLM(28.6 nmol/ml)的致突变作用(P＜0.05);而维生素E浓度为10μl/ml时,可极显著地拮抗BLM的作用(P＜0.01);当加入牛黄酸的终浓度为100和200μg/rl时,均可显著地拮抗BLM(28.6nmol/m1)的致突变作用(P＜0.05).结论一定剂量的维生素E和牛黄酸对BLM的致突变性存在着拮抗作用.     

Dimethoate induced oxidative damage and histopathological changes in lung of adult rats: modulatory effects of selenium and/or vitamin E

Objective To determine the efficiency of selenium and/or vitamin E to alleviate lung oxidative damage induced by dimethoate,an organophosphorus compound.Methods Adult Wistar rats were exposed during 30 days either to dimethoate (0.2 g/L of drinking water),dimethoate+selenium (0.5 mg/kg of diet),dimethoate+vitamin E (100 mg/kg of diet),or dimet hoate+selenium+vitamin E.Results Exposure to dimethoate caused oxidative stress in lung evidenced by an increase of malondialdehyde,protein carbonyl groups and advanced oxidation protein products.An increase in glutathione peroxidase,superoxide dismutase,catalase and a decrease in acetylcholinesterase and butyrylcholinesterase activities,glutathione,non-protein thiols and vitamins C levels were observed.Histopathological changes in lung tissue were noted as emphysema,hemorrhages and hemosiderin deposits.Co-administration of selenium or vitamin E to the diet of dimethoate treated rats ameliorated the biochemical parameters as well as histological impairments.The joint effect of these elements was more powerful in antagonizing dimethoate-induced lung oxidative damage.Conclusion We concluded that selenium and vitamin E ameliorated the toxic effects of this pesticide in lung tissue suggesting their role as potential antioxidants.     

Vitamin E, selenium and methionine supplementation of dystrophogenic diets for pigs

Forty-eight weanling S.P.F. Yorshire pigs were used to study the influence of supplemental vitamin E (25 IU per kg of diet) selenium (0.5 ppm in diet) and methionine (0.1% in diet) on the incidence of hepatosis dietetica and mulberry heart disease when fed a torula yeast-corn diet. Vitamin E and/or selenium increased pig survival. Supplemental selenium resulted in increased liver selenium concentrations. No hepatosis dietetica was observed in any of the pigs. The addition of vitamin E and/or selenium at the levels used did not reduce the frequency of myocardial lesions; however, they prevented skeletal muscular dystrophy and exudative diathesis. The myocardial lesions were less severe in supplemented pigs compared with unsupplemented controls.     

Protective action of selenium and manganese on xanthine and xanthine oxidase induced oxidative damage to cultured heart cells.

Ventricular myocytes from neonatal Wistar rats were cultured with 80% Dulbecoo's modified Eagle medium and 20% fetal bovine serum. An appropriate amount of xanthine and xanthine oxidase was added to the culture medium to increase the content of free radicals in cardiac cells. Variation in action potential and input impedance of cardiac myocytes indicated the oxidative damage to the membrane. The ultrastructure of heart cells, characteristically the myofilaments and mitochondria, was damaged. Electron spin resonance measurement demonstrated that xanthine and xanthine oxidase elevated the free radical content, while selenium (Se) and manganese (Mn) reduced the free radicals in cultured heart cells. Supplementation of 0.173 microgram/ml Se and 0.1 microgram/ml Mn into the culture medium separately or simultaneously antagonized the damage induced by xanthine and xanthine oxidase. The possible mechanism might be the production of superoxide anion free radical leading to free radical damage to cardiac cells. Se and Mn might play a role as scavengers through glutathione peroxidase and superoxide dismutase respectively and thus protect cardiac cells from free radical damage.

     

抗氧化剂对Ox—LDL诱导内皮细胞Bcl-2蛋白表达的影响

目的　探讨抗氧化剂Se和VitE对Ox -LDL诱导体外培养的牛主动脉内皮细胞Bcl -2蛋白的影响。　方法　Ox -LDL与VitE、Se处理牛主动脉内皮细胞后 ,通过流式细胞仪和DNA电泳检测细胞凋亡 ,采用Westernblot检测Bcl -2蛋白表达。　结果　Ox -LDL作用内皮细胞后 ,DNA电泳呈明显梯度条带 :加入Se和VitE后 ,内皮细胞平均凋亡率较Ox -LDL组明显降低 (P <0 .0 5 ) ,Westernblot检测Bcl -2蛋白表达明显增加 (P <0 .0 5 )。　结论　Se和VitE能减少Ox -LDL诱导体外培养的牛主动脉内皮细胞凋亡 ,其作用机制与上调Bcl -2蛋白表达有关     

维生素E抑制3T3-L1前脂肪细胞的分化

目的:研究维生素E对3T3-L1前脂肪细胞增殖和分化的影响。方法:利用MTT研究维生素E对3T3-L1前脂肪细胞增殖的影响,利用油红O染色法测定维生素E对3T3-L1前脂肪细胞分化的影响。结果:维生素E对3T3-L1前脂肪细胞增殖无影响,10～100μmol/L维生素E能抑制3T3-L1前脂肪细胞的分化。结论:维生素E对前脂肪细胞分化具有抑制作用。     

钌卟啉03及04对鼻咽癌细胞1及2、结肠癌SW480细胞体外增殖和凋亡的影响

目的 探讨新型钌卟啉化合物(Rup)-03、Rup-04对高分化鼻咽癌细胞(CNE)-1、低分化CNE-2和结肠癌SW480细胞体外增殖和凋亡的影响.方法 经光照和不同浓度(10-10 mol/L、10-9 mol/L、10-8 mol/L、10-7 mol/L、10-6 mol/L、10-5 mol/L)Rup-03或Rup-04联合作用后,联合磺酞罗丹明B法和吉姆萨染色法观察CNE-1、CNE-2和SW480细胞的形态学变化及其增殖和凋亡的情况,邻苯三酚自氧化法和Griess法测定其超氧阴离子和NO表达.结果 随着Rup-03、Rup-04作用浓度的升高,CNE-1、CNE-2和SW480细胞凋亡增多,对超氧阴离子的清除能力降低,细胞内NO表达升高(均P<0.05),且Rup-03对3种肿瘤细胞的光动力抑制作用均强于Rup-04(P<0.05).结论 Rup-03和Rup-04均对CNE-1、CNE-2和SW480肿瘤细胞有浓度依赖性的促凋亡作用,其抗肿瘤机制可能与Rup-03、Rup-04产生自由基诱导细胞凋亡有关.     

维生素B12对氧化应激损伤下神经细胞的保护机制

目的：探索维生素B12预处理对H2O2诱导下的神经细胞损伤的保护作用及自噬和凋亡蛋白表达的影响。方法：将大鼠肾上腺髓质嗜铬瘤分化细胞（PC12）分为对照组（Control组）RPMI 1640培养、损伤组（H2O2组）RPMI 1640培养并加入200 μmol/L的H2O2刺激,维生素B12保护组（H2O2+VitB12组）RPMI 1640培养加入200 μmol/L维生素B12预处理和200 μmol/L的H2O2刺激。24 h后检测细胞的活性,Western blot和免疫荧光检测凋亡及自噬相关蛋白表达水平。结果：与Control组比较,H2O2组的细胞存活率、细胞DNA复制水平降低,Bcl-2和P62蛋白的表达量下降,Bax、ATG-5和LC3蛋白的表达量明显上升,胞浆内LC3的激活数量上升（均P＜0.05)。与H2O2组比较,H2O2+VitB12组细胞存活率和细胞DNA复制水平上升,Bcl-2和P62蛋白的表达量上升,Bax、ATG-5和LC3蛋白的表达量显著下降,胞浆内LC3的激活数量下降（均P＜0.05)。结论：维生素B12能通过调控自噬抑制氧化应激诱导下的细胞凋亡。     

硒对3T3-L1前脂肪细胞增殖和分化的影响

目的:研究硒对3T3-L1前脂肪细胞增殖和分化的影响。方法:培养3T3-L1前脂肪细胞,分为对照组、低硒组、中硒组和高硒组(亚硒酸钠浓度分别为0、0.01、0.1和1μmol/L),采用四甲基偶氮唑盐比色(MTT)法检测硒对3T3-L1前脂肪细胞增殖的影响,利用油红O染色法测定硒对3T3-L1前脂肪细胞分化的影响。结果:在增殖实验中,与对照组相比,各处理组的OD值降低,并具有剂量依赖性(P<0.05);在分化实验中,各处理组的OD值与对照组差异无统计学意义(P>0.05)。结论:硒能抑制3T3-L1前脂肪细胞的增殖,而对其分化无影响。     

探讨流式细胞仪测定不同浓度维生素K3对肝癌细胞凋亡周期的影响

目的:对维生素K3诱导肝癌细胞分子凋亡机制进行初步探讨从而达到指导临床肝癌治疗的作用。方法:对人类肝癌细胞株HCC-9204进行培养并选取对数生长期的肝癌细胞,不同浓度及时间的维生素K3进行诱导,通过荧光染色法在激光共聚焦显微镜下观察凋亡细胞核形态。CKK-8法对维生素K3抑制HCC-9204细胞增值,使用流式细胞仪检测细胞凋亡率、凋亡周期及细胞膜Fas表达情况。结果:经维生素K3进行诱导CCK-8检验肝癌细胞比率明显下降,自身生长抑制率上升且呈现明显的计量依赖性,荧光染色后发现细胞凋亡中期细胞凋亡细胞核呈现波纹状或折缝样,有部分染色质出现浓缩,中晚期凋亡细胞核染色质呈现高度凝聚且边缘化,细胞核裂解呈现碎块状并产生凋亡小体。流式细胞仪检测不同浓度VK3作用的肝癌细胞珠HCC-9204在48h时2μmol/L凋亡率为31.44%,5μmol/L凋亡率为62.81%,10μmol/L凋亡率为76.89%,20μmol/L凋亡率为89.24%,25μmol/L凋亡率为93.58%。结论:维生素K3诱导肝癌细胞凋亡48h时呈现明显浓度计量依赖性,荧光染色法在能动速度态观察差细胞核凋亡变化并可以进行定量、定性分析。     

维生素E通过抑制铁坏死减少放射性神经损伤

目的 背景 探索维生素E在海马神经元放射性损伤过程中的作用并探讨其可能机制。方法 HT-22细胞及U251细胞体外培养，分别设置对照组：细胞正常培养；单纯放疗组（RT）：放射线单次照射8 Gy；VE组：维生素E（200 μmol/L）处理24 h；Fer-1 组：铁坏死抑制剂（Ferrostatin-1，5 μmol/L）处理24 h；RT+VE组：放疗联合维生素E处理；RT+Fer-1组：放疗联合铁坏死抑制剂处理；RT + ZVAD 组：放疗联合凋亡抑制剂（ZVAD-FMK, 2 μmol/L）处理；RT + Necro-1 组：放疗联合坏死性凋亡抑制剂（nerosulfonamide, 100 μmol/L）处理。MTT实验测定各组细胞生长情况。检测铁坏死相关氧化应激指标包括还原型谷胱甘肽（GSH）、丙二醛（MDA）、脂质活性氧簇（Lipid ROS）以及细胞内铁离子水平评估各组细胞铁坏死状态。实验小鼠根据随机数表法随机分为4组（3只/组）：对照组：小鼠正常喂养；VE组：维生素E（500 U/kg）饮食喂养6周；RT组：小鼠全脑单次16 Gy照射；RT+VE组：放疗联合维生素E处理。观察各组小鼠水迷宫实验的探索时间及探索距离评估小鼠认知功能状况。结果 与RT组相比，RT+VE组HT-22细胞存活增加（P<0.05），U251无明显改变（P>0.05）；RT+Fer-1组HT-22细胞存活也明显增加（P<0.05），RT+ZVAD组和RT+Nerco-1组HT-22细胞存活无改变（P>0.05）。与对照组相比，RT组HT-22细胞铁坏死相关氧化应激水平上 升，包括GSH下降、MDA及Lipid ROS水平上升，细胞内铁离子水平增加（P<0.05）；而与RT组相比，RT+VE组及RT+Fer-1组能逆转铁坏死相关氧化应激水平改变（P<0.05）。与对照组及VE组比较，RT组小鼠水迷宫实验中游行的距离和探索时间较RT组明显增加（P<0.05）；RT+VE组小鼠相比于RT组水迷宫探索距离及时间均有明显下降（P<0.05）。结论 铁坏死，而非凋亡和坏死性凋亡，是海马神经元放射性损伤过程中的重要因素，维生素E能通过抑制铁坏死减少放射性神经损伤。     

硒对紫外线诱导HLF细胞凋亡的保护作用

目的：探讨紫外线诱导人HLF细胞凋亡时DNA降解特点，以及硒对紫外线诱导细胞凋亡的保护作用。方法：紫外线分别照射体外培养的人肺成纤维细胞3min和5min，同时添加亚硒酸钠（8ng/ml），设立对照组。利用吖啶橙荧光染料染色鉴定凋亡细胞，利用琼脂糖凝胶电泳检测DNA ladder。结果：紫外线可以诱导人肺成纤维细胞（28代）凋亡，作用存在时间效应关系。紫外线诱导人肺成纤维细胞凋亡时，未出现典型的DNA ladder现象。硒对于紫外线诱导的细胞凋亡有显著的抑制作用。结论：DNA ladder不能作为细胞凋亡的唯一的标志，紫外线诱导的细胞凋亡与DNA ladder的出现并不总是一致的。硒具有拮抗紫外线诱导的细胞凋亡作用。     

齐墩果酸对损伤血管内皮细胞的保护作用及其机制探讨

目的:探讨齐墩果酸(oleanic acid,OA)对过氧化氢(hydrogen peroxide,H2O2)诱导人血管内皮细胞(human umbilical vein endothelial cells,HUVECs)损伤的保护作用及其机制?方法:培养HUVECs,分为正常组?H2O2模型组?H2O2+OA (0.25 ?滋mol/L)组?H2O2+OA (0.50 ?滋mol/L)组?H2O2+OA (1.00 ?滋mol/L)组?H2O2+维生素C(1.50 mmol/L)组?各组培养24 h后,通过MTT法检测细胞增殖能力,酶生化法测定上清液中的乳酸脱氢酶(lactate dehydrogenase,LDH)和一氧化氮(nitric oxide,NO)含量,酶生化法测定细胞裂解液中的丙二醛(malondialdehyde,MDA)含量?谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)和超氧化物歧化酶(superoxide dismutase,SOD)活力,流式细胞仪测细胞内活性氧(reactive oxygen species,ROS)和细胞凋亡率?结果:OA能够恢复H2O2损伤的细胞活力,减轻H2O2诱导的LDH释放,减少H2O2诱导的MDA生成,恢复H2O2损伤的GSH-Px和SOD活力,清除H2O2诱导的ROS,减轻H2O2诱导的细胞凋亡,提高HUVECs细胞NO的生成?结论:OA对损伤血管内皮细胞有保护作用,这与OA能够启动HUVECs细胞内抗氧化防御机制,清除细胞内的ROS,提高HUVECs细胞NO的生成,抑制H2O2诱导的HUVECs细胞凋亡有关?     

硒化壳聚糖对K562细胞的作用及其与NF-КB信号分子的关系

目的:研究硒化壳聚糖对慢性粒细胞白血病细胞株K562增殖的影响,并且探讨这种影响与NF-КB信号分子的关系。方法:MTT法检测硒化壳聚糖对细胞增殖的影响,AO/EB荧光染色用来观察药物对细胞的凋亡作用。Westernblot的方法检测蛋白含量的变化。结果:硒化壳聚糖对K562细胞抑制作用呈量效、时效关系,硒化壳聚糖200mg/L作用48h对K562细胞的抑制率高达90.7±10%;并使细胞出现明显的凋亡现象。Westernblot的实验结果表明硒化壳聚糖使K562细胞NF-КB蛋白含量明显减少,且呈量效关系。结论:硒化壳聚糖可减少进入细胞核内NF-КB的蛋白含量从而下调其下游基因表达,最终抑制K562细胞增殖,诱导细胞发生凋亡。     

冬凌草甲素对活性氧自由基的清除作用(英文)

目的：研究冬凌草甲素对不同模型系统产生的活性氧自由基的清除作用。方法：自由基检测用电子自旋共振自由基旋捕集技术和化学发光法。结果：二种方法检测均发现Ｏｒｉｄ明显清除黄嘌呤／黄嘌呤氧化酶系统产生的超氧自由基（Ｏ－２）以及Ｆｅｎｔｏｎ反应中的羟自由基（·ＯＨ）．Ｏｒｉｄ１７０ｍｏｌ／Ｌ对Ｏ－２和·ＯＨ的清除率分别为４９４％和７５２％。Ｏｒｉｄ对多形核白细胞（ＰＭＮ）呼吸爆发时产生活性氧自由基同样显示明显清除作用。在本实验条件下,Ｏｒｉｄ并不影响ＰＭＮ呼吸爆发时的氧消耗。结论：Ｏｒｉｄ可能是一个抗氧化剂。     

Effects of free radicals and amyloid β protein on the currents of expressed rat receptors in Xenopus oocytes

Objective To investigate the effects of free radicals (FRs) and amyloid β protein 1-40 ( Aβ(1-40)) on the functions of expressed neurotransmitter receptors (NRs) i n Xenopus oocytes.Methods Total RNA and messenger RNA (mRNA) was prepared from 3-month-old Wistar rat br ain tissues with Promega kits and microinjected into maturated Xenopus oocyt es (stages Ⅴ-Ⅵ) with 50 nl (50 ng) for each oocyte. The microinjec ted oocy tes were incubated with modifiedBath’s solution at 19.0℃±1.0℃ for receptor expression and their currents were recorded with double electrode voltage clamp technique. Superoxide anion free radicals (SAFRs) were produced via a reaction system (HPXXO) with hypoxanthine (HPX, 0.05 mol/L) and xanthine oxidase (XO, 0.1 U/L). In order to observe the effects of Aβ and SAFRs on the e xpressed glutamate receptor, HPX/XO and Aβ(1-40) were added to incubation solution at 12 h, 24 h and 96 h before recording.Results The results showed that the oocytes expressed functional NRs originating from ra t brain tissues. These NRs included muscarinic acetylcholine (mACh), glutamate (Glu), dopamine (DA), serotonin (5-HT) and γ-aminobutyric acid (GABA). T he c urrent characteristics of expressed receptors were inward currents carried by ch loride ion with their equibrilium potentials close to -22 mV. The extent of ef fect on the current of expressed glutamate receptor from rat brain was different among different Aβ concentrations and incubation times. Aβ(1-40) at a c oncentration of 20 nmol/L had little effect on the currents of expressed rat br ain glutamate receptors up to 24 h of incubation period; but the currents of gl utamate receptor were significantly decreased (25% off, P&lt;0.01) in the trea tment of 60 nmol/L Aβ(1-40) over 24 h. Moreover, when 20 nmol/L Aβ (1-40) was co-incubated over 12 h with SAFRs produced by the reaction syste m of HPXXO, it was found that the currents of expressed rat bra in glutamate rec eptors had been changed markedly. When the oocytes were co-treated with 60 nm ol/L Aβ(1-40) and SAFRs over a period of 12 h, the currents of glutamate receptor significantly decreased (21% off, P&lt;0.05), and the decreased perce ntage reached 52% over 24 h co-treatment with 60 nmol/L Aβ(1-40) and SA FRs. In addition, vitamin E had a partial effect against this inhi bitory effect.Conclusion The results suggest that Aβ has a kind of inhibitory effect upon the current of the glutamate receptor, similar to the effects of free radicals. The effects c an be antagonized by vitamin E. These imply that Aβ may play a role via inhibi ting receptor function in the pathophysiology of Alzheimer’s disease.     

硒对镉转化人支气管上皮细胞系16HBE凋亡和癌基因表达的影响

目的研究在体外染毒条件下硒对镉转化人支气管上皮细胞系16HBE凋亡和癌基因表达的影响。方法用0.625、1.25、2.5和5.0μmol/L亚硒酸钠染毒镉转化16HBE细胞24h,用流式细胞术检测凋亡,用RT-PCR检测p53,bcl-2和bax表达。结果 0.625、1.25、2.5和5.0μmol/L亚硒酸钠染毒镉转化16HBE细胞后,随硒剂量升高细胞凋亡率增高,相关系数r=0.987 9(P<0.01),并且在1.25、2.5和5.0μmol/L亚硒酸钠剂量组的凋亡率与对照组相比差异具有统计学意义(P<0.05或P<0.01)。亚硒酸钠可以抑制镉转化16HBE细胞p53和bcl-2的表达(P<0.05或P<0.01),bax表达虽有所增强但P>0.05。进行相关性分析,细胞凋亡与p53和bcl-2表达呈负相关,相关系数r分别为-0.923 6(P<0.01)和-0.862 1(P<0.05),而细胞凋亡与bax表达呈正相关,相关系数r=0.781 8(P<0.05)。p53表达和bcl-2表达呈正相关,相关系数r=0.894 1(P<0.05)。p53、bcl-2表达和bax表达之间呈显著负相关,相关系数分别为-0.822 2(P<0.05)和-0.961 3(P<0.01)。结论亚硒酸钠处理镉转化16HBE细胞,通过使p53和bcl-2表达下调、bax表达上调,诱导细胞凋亡从而起到抑制细胞恶性转化的作用。     

Synergistic effect of zinc and vitamin A on T cell functions

Objective To determine whether supplementation of zinc and vitamin A may improve the function of T cells in human PBMC. Methods T cells were separated and cultured in vitro,supplemented with either Zn or vitamin A alone,or both Zn and vitamin A(10-6 mol/L,10-5 mol/L,10-4 mol/L). After harvesting,cell proliferation,cell cycle,apoptosis,expression or function of cell-surface molecules,such as CD3 ,CD4 ,and CD8 were detected. Results Higher proliferation level and lower apoptosis level were observed in cells supplemented with both Zn and vitamin A,showing the strongest effect(P<0.05). Zn-supplement increased the CD4 /CD3 cell percentage,and simultaneously decreased the CD8 /CD3 cell population. VA-supplement showed the opposite effect in comparison with Zn-supplement. Conclusion T-cell function can be improved,depending on the zinc and/or vitamin A supplemented.     

不同价态锰对神经细胞的毒性比较以及硒的保护作用

目的研究不同价态锰化合物对神经母细胞瘤细胞(SH-SY5Y)DNA损伤作用、细胞凋亡和细胞周期的影响,以及抗氧化剂硒的保护作用,从而探讨锰的神经毒作用机制。方法将培养的SH-SY5Y细胞随机分为染毒的二价锰和三价锰化合物(0.5 mmol/L)组、空白对照组、硒干预组。培养24 h后应用单细胞凝胶电泳检测细胞DNA链断裂情况。48 h后用流式细胞仪测定细胞凋亡率、细胞周期分布。结果三价锰组DNA损伤程度比二价锰组严重。二价锰和三价锰组均出现亚二倍体的凋亡峰;细胞周期分布也发生改变,与对照组相比S期细胞明显增多,差异有统计学意义(P<0.01);三价锰比二价锰更易引起细胞凋亡(P<0.01)和细胞周期变化(P<0.05)。硒可降低锰化合物引起的细胞DNA损伤、凋亡率和细胞周期中S期细胞数。结论不同价态锰对神经细胞均有损伤作用,且三价锰大于二价锰。硒对锰致细胞DNA损伤、凋亡和细胞周期改变有一定的保护作用,提示氧化应激可能参与了锰的毒作用。