L.SP.HXQ001菌对家兔血清胆固醇的影响

目的 探讨乳酸细菌中的明串珠菌对血清胆固醇的影响。方法 通过给实验性高胆固醇血症家兔喂L.sp.HXQ001菌液,测定其血清胆固醇含量,并与持续高脂喂饲、停高脂喂饲后自然降低血清胆固醇比较,分析其对脂代谢的影响。结果 L.sp.HXQ001菌有预防高脂饲料所引发的高胆固醇血症作用,对实验性高胆固醇血症有较好的降低血清胆醇作用。结论：L.sp.HXQ001菌显示有较好的调节血清胆固醇作用,有可能成为新的微生态调节剂,并在防治高胆固醇血症方面发挥作用。     

抗氧化乳酸菌在体外结肠环境清除羟自由基的研究

目的利用鼠肝匀浆经Fe^2＋ -VitC诱导产生丙二醛（MDA）为模型研究29株乳酸菌的抗氧化活性。方法建立体外模拟结肠发酵体系,分析3株具有不同抗氧化能力的乳酸菌（Lactobacillus paracasei Fn032,Laaobacillus rhamnosus GG,Lactobacillus sp．Fn001）在正常结肠和铁过载结肠模型中清除羟自由基效果及对肠球菌增殖的的影响,并检测3株菌螯合亚铁离子能力及其无细胞提取物超氧化物歧化酶（SOD）活性。结果体外结肠体系中羟自由基含量与肠球菌数量有显著相关性。在正常结肠环境中,3株乳酸菌清除羟自由基能力与其SOD活性一致,但与其抑制肠球菌增殖能力和螯合亚铁离子能力不一致。在高铁结肠环境中,3株乳酸菌清除羟自由基能力与它们抑制肠球菌增殖能力和螯合亚铁离子能力一致,但与SOD活性不一致。结论正常条件下乳酸菌可通过产生抗氧化酶来清除结肠自由基,铁过载条件则可增强具有铁螯和能力乳酸菌的抗氧化活性。     

香菇多糖体内抗氧化活性研究

目的：探究香菇多糖的体内抗氧化活性。方法：以灌胃生理盐水的小鼠为正常对照组,将香菇多糖药物组分为低、中、高3种剂量组。小鼠在灌胃3w后,由眼眶取血,按照试剂盒要求测定小鼠血清中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）活力以及丙二醛（MDA）含量。结果：香菇多糖可显著提高小鼠血清中SOD和GSH-Px的活力,同时减少血清中MDA含量。结论：香菇多糖对小鼠体内抗氧化活性的提高具有显著作用。     

大豆卵磷脂对小鼠的抗疲劳和抗氧化作用研究

目的：研究大豆卵磷脂的抗疲劳及抗氧化作用。方法：小鼠经口给予大豆卵磷脂30天后,采用负重游泳实验,观察记录小鼠游泳死亡时间;检测血清尿素氮、肝糖原;测定血清和肝匀浆超氧化物歧化酶（SOD）活性、谷胱甘肽过氧化物酶（GSH—Px）活力、丙二醛（MDA）含量。结果：给予大豆卵磷脂后,与对照组相比,实验组小鼠负重游泳时间明显延长,肝糖原消耗量减少,降低运动后血清尿素氮水平（P〈0．05）;升高小鼠血清和肝匀浆SOD活性及GSH-Px活力,降低MDA的含量（P〈0．05）。结论：大豆卵磷脂具有抗疲劳和抗氧化作用。     

脱氢表雄酮对大鼠脂类代谢和抗氧化作用的影响

目的：研究灌胃脱氢表雄酮（DHEA）对大鼠脂类代谢和抗氧化作用的影响。方法：选用健康雄性SD大鼠40只,随机分为4组（n=10）。对照组灌胃给予灭菌生理盐水,实验组灌胃给予20mg／kg、10mg／kg、5mg／kg体重的DHEA受试溶液,灌胃量均为1．5ml。每天一次,连续35d。实验结束后采血测定血糖（BG）、甘油三酯（TG）、总胆固醇（TO）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）,血清和肝脏超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量。结果：DHEA显著降低大鼠血糖、TG、HDL-c及血清和肝脏MDA含量,显著升高血清LDL-c含量和肝脏SOD活性,而对大鼠体重、血清TC含量和SOD活性没有显著影响。结论：DHEA具有降低大鼠血脂和增强抗氧化能力的作用。     

低温对黑线仓鼠能量代谢、抗氧化能力和氧化应激的影响

为探讨低温对机体能量代谢、器官/组织抗氧化能力和过氧化自由基水平的影响及其内在联系,本研究测定了不同时间低温和梯度低温处理的黑线仓鼠的摄食量、体重、主要内脏器官/组织的过氧化物歧化酶（SOD）、过氧化氢酶（CAT）、H₂O₂和丙二醛（MDA）水平。低温使摄食量显著增加,但未影响体重。低温暴露42 d使心脏和骨骼肌MDA水平、骨骼肌SOD活性显著升高;梯度低温使脑和肾脏H₂O₂水平、肝脏和骨骼肌SOD活性显著降低,使脑、肝脏、肺、肾脏MDA水平、脑和小肠SOD活性显著升高。抗氧化能力和过氧化自由基水平在不同器官之间相关性存在差异,同一器官内二者的相关性在肾脏为100%,肝脏66.7%,骨骼肌50.0%。结果表明：（1）过氧化自由基的产生与低温暴露的时间和程度有关;（2）不同器官/组织过氧化自由基水平不同;（3）部分器官/组织抗氧化酶活性的变化与过氧化自由基水平的变化密切相关,可能是防止过氧化损伤的主要防御系统。     

昆布（海带）对高脂血症大鼠血脂的调节作用和机制

目的：探讨昆布（海带）在实验性高脂血症大鼠中的降血脂作用和机制。方法：健康雌性Wistar大鼠40只,应用高脂饲料喂养方法建立高脂血症动物模型,海带粉饲料喂养干预治疗。生化法检测大鼠血清甘油三酯（TG）、总胆固醇（TC）、低密度脂蛋白（LDL）和高密度脂蛋白（HDL）水平。硫代巴比妥酸法和硝酸还原酶法分别检测脂质过氧化物丙二醛（MDA）和一氧化氮（NO）含量,黄嘌呤氧化酶法和化学比色法分别测定超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-PX）活性。结果：经海带干预治疗后,动物血清TG、TC和LDL水平较模型组显著降低、HDL水平显著升高（P〈0.05）。治疗组动物血清和肝组织MDA和NO水平显著低于、而SOD和GSH-PX活性均显著高于模型组（P〈0.05）。结论：海带可能影响TG、TC、LDL和HDL等组分的代谢,通过增强抗氧化SOD和GSH-PX的活性,降低体内MDA和NO的水平,发挥调节血脂水平的作用。     

缺血预处理对肢体缺血/再灌注时肺损伤的保护作用

目的：观察肢体缺血/再灌注（LI/R）时肺损伤的变化并探讨缺血预处理（IPC）对其保护作用。方法：复制家兔LI/R损伤模型,观察肢体缺血4 h再灌注4 h肺损伤的变化以及采用肢体IPC干预后对肺损伤的影响。从右颈外静脉和左颈总动脉采血,分别代表入肺血和出肺血,检测入、出肺血及肺组织超氧化物歧化酶（SOD）的活性、脂质过氧化物的代谢产物丙二醛（MDA）和一氧化氮（NO）的含量;同时测定肺组织总一氧化氮合酶（tNOS）和诱导型一氧化氮合酶（iNOS）的活性以及肢体IPC对上述指标的影响。结果：与对照组和缺血前比较,LI/R组松夹再灌注4 h入、出肺血及肺组织SOD活性明显降低,MDA和NO含量增高（P〈0.05,P〈0.01）;肺组织tNOS和iNOS活性亦升高,与对照组比较,有统计学意义（P〈0.01）。在缺血前给予IPC组,SOD活性升高,而MDA、NO含量降低,tNOS、iNOS活性也降低（P〈0.01）。相关分析显示MDA与SOD间存在明显负相关（P〈0.01）,而MDA与NO及iNOS呈显著正相关（P〈0.01）。结论：LI/R时并发的急性肺损伤与组织氧化代谢紊乱有关,IPC通过改善LI/R时肺组织氧化与抗氧化之间的平衡,进而增强肺组织的抗氧化能力,对LI/R肺损伤具有保护作用。     

油橄榄叶提取物体内外抗氧化活性研究

为评价油橄榄叶提取物的体内和体外抗氧化能力,体外抗氧化活性评价采用DPPH·和·OH清除能力实验,体内抗氧化活性评价采用D-半乳糖连续背部注射制作亚急性衰老小鼠模型,以VE为阳性对照组,油橄榄叶提取物58、116、232 mg/kg BW灌胃30 d,处死后测定MDA含量、SOD和GSH-Px活性,观察肝脏和大脑组织病理形态学的改变。结果表明,衰老小鼠MDA的含量明显升高,血清、肝组织中的SOD、GSH-Px和脑组织中的SOD活性均明显降低,与正常小鼠比较有差异(P0.05);各剂量的油橄榄叶提取物均能提高衰老小鼠血清、肝组织中的SOD、GSH-Px和脑组织中的SOD活性,并降低MDA的含量;油橄榄叶提取物可明显改善D-gal致衰老小鼠肝脏、大脑皮质和海马神经元的细胞形态和水肿情况。油橄榄叶提取物清除DPPH·和·OH的IC50分别为0.064 mg/m L和0.066 mg/m L。实验结果表明油橄榄叶提取物具有较好的抗氧化活性。     

油橄榄叶提取物体内外抗氧化活性研究北大核心CSCD

为评价油橄榄叶提取物的体内和体外抗氧化能力,体外抗氧化活性评价采用DPPH·和·OH清除能力实验,体内抗氧化活性评价采用D-半乳糖连续背部注射制作亚急性衰老小鼠模型,以VE为阳性对照组,油橄榄叶提取物58、116、232 mg/kg BW灌胃30 d,处死后测定MDA含量、SOD和GSH-Px活性,观察肝脏和大脑组织病理形态学的改变。结果表明,衰老小鼠MDA的含量明显升高,血清、肝组织中的SOD、GSH-Px和脑组织中的SOD活性均明显降低,与正常小鼠比较有差异(P<0.05);各剂量的油橄榄叶提取物均能提高衰老小鼠血清、肝组织中的SOD、GSH-Px和脑组织中的SOD活性,并降低MDA的含量;油橄榄叶提取物可明显改善D-gal致衰老小鼠肝脏、大脑皮质和海马神经元的细胞形态和水肿情况。油橄榄叶提取物清除DPPH·和·OH的IC50分别为0.064 mg/m L和0.066 mg/m L。实验结果表明油橄榄叶提取物具有较好的抗氧化活性。     

L.sp.HXQ 001 菌在小鼠肠道定植的实验研究

研究Ｌ·ｓｐ．ＨＸＱ００１菌株对小鼠的有益作用。通过对口服该菌液使之定植于小鼠肠道,分离小鼠粪便、肠段匀浆中该菌菌落及作肠段切片ＨＥ染色,肠道的正常防御机制不能杀灭该菌,并能在小鼠肠道定植,且以结肠为主。该菌定植肠段有淋巴细胞浸润,但无变性坏死等变化,显示生理性炎症反应。Ｌ．ｓｐ．ＨＸＱ００１菌株不是小鼠肠道正常菌群但仍可定植于肠道、激发机体免疫应答。有望成为新的肠道微生态调节剂。     

THE VARIATION OF ANTIOXIDANT DEFENSE SYSTEM OF Streptomyces sp. M4018 WITH RESPECT TO CARBON SOURCES

The effect of glycerol, glucose, and starch as carbon sources on the antioxidant defense system such as superoxide dismutase (SOD) and catalase (CAT) activities, pyruvate levels, and membrane lipid peroxidation (LPO) levels of Streptomyces sp. M4018, after isolation from the rhizosphere samples of Colutea arborescens and identification as a strain of S. hiroshimensis based on phenotypic and genotypic characteristics, were investigated. As an antioxidant defense enzyme, SOD activities increased up to 20 g/L of glycerol and 15 g/L of starch, while they showed negative correlation with glucose concentration. CAT activity variations of glycerol- and glucose-supplemented mediums showed significant positive correlations with the trend of SOD activities. However, CAT activity, in contrast to SOD, in Streptomyces sp. M4018 tended to decrease as the starch concentration increased. The production of pyruvate increased with respect to glycerol and starch up to 15 g/L, while it was positively correlated with glucose concentration. The highest pyruvate production was seen at 20 g/L glucose. Membrane LPO levels were negatively correlated with the activities of SOD and CAT enzymes, and the minimum LPO level was determined at 5 g/L of glucose, where SOD and CAT activities reached their maximum levels. Nevertheless, the higher SOD and CAT activities in a wider range of incubation period compared to the beginning by resulting in insignificant increases in membrane LPO levels showed the unusual antioxidant response capacities of the in Streptomyces sp. M4018 against the potentially deleterious effects of reactive oxygen species (ROS) for glycerol, glucose, and starch as carbon sources.     

转柽柳eIF1A基因烟草的耐盐性分析

目的:验证柽柳eIF1A基因的功能,为通过基因工程手段培育耐盐植物提供基础资料。方法:对转eIF1A基因的烟草和对照烟草进行不同浓度NaCl胁迫实验,测定其相对电导率、SOD活性和丙二醛含量,统计生根率、生长量和盐害程度。结果:转基因烟草的相对电导率、丙二醛含量均随盐浓度的增加而增大,但都较非转基因对照烟草低。SOD活性随着盐浓度的升高而升高,相同浓度NaCl胁迫下各转基因烟草的SOD活性均高于对照烟草的SOD活性。NaCl浓度为240mmol/L时,非转基因对照烟草不能生根,盐害指数高达67.7%;而转基因烟草均能生根,大部分转基因株系的生根率大于50%。结论:柽柳eIF1A基因的转化提高了烟草的耐盐性。     

Melatonin ameliorates carbon tetrachloride-induced hepatic fibrogenesis in rats via inhibition of oxidative stress

Melatonin is reported to exhibit a wide variety of biological effects, including antioxidant and anti-inflammatory. Evidence shows the important role of oxidative stress in the etiopathogenesis of hepatic fibrosis. The aim of this study was to investigate the protective effects of administration of melatonin in rats with carbon tetrachloride-induced fibrosis for 6 weeks. Hepatic fibrotic changes were evaluated biochemically by measuring tissue hydroxyproline levels and histopathogical examinations. Malondialdehyde (MDA), an end product of lipid peroxidation, and glutathione peroxidase (GSH-px) and superoxide dismutase (SOD) levels were evaluated in tissue homogenates by spectrophotometry. The nuclear factor-kappaB (NF-kappaB) in liver tissue was examined by immunohistochemistry. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) concentrations in Kupffer cells (KCs) culture supernatants were measured with ELISA. The rats injected subcutaneously with CCl4 for 6 weeks resulted in hepatic fibrotic changes increased hydroxyproline and MDA levels, and decreased GSH-px and SOD levels, whereas melatonin reversed these effects. Furthermore, melatonin inhibited the expression of NF-kappaB in liver tissue and decreasing production of proinflammatory cytokines such as TNF-alpha and IL-1beta from KCs in fibrotic rats. These present results suggest that melatonin ameliorates carbon tetrachloride-induced hepatic fibrogenesis in rats via inhibition of oxidative stress and proinflammatory cytokines production.     

Early memory deficits precede plaque deposition in APPswe/PS1dE9 mice: involvement of oxidative stress and cholinergic dysfunction

A large body of evidence has shown that cognitive deficits occur early, before amyloid plaque deposition, suggesting that soluble amyloid-β protein (Aβ) contributes to the development of early cognitive dysfunction in Alzheimer disease (AD). However, the underlying mechanism(s) through which soluble Aβ exerts its neurotoxicity responsible for cognitive dysfunction in the early stage of AD remains unclear so far. In this study, we used preplaque APPswe/PS1dE9 mice ages 2.5 and 3.5 months to examine alterations in cognitive function, oxidative stress, and cholinergic function. We found that only soluble Aβ, not insoluble Aβ, was detected in these preplaque APPswe/PS1dE9 mice. APPswe/PS1dE9 mice 2.5 months of age did not show any significant changes in the measures of cognitive function, oxidative stress, and cholinergic function, whereas 3.5-month-old APPswe/PS1dE9 mice exhibited spatial memory impairment in the Morris water maze, accompanied by significantly decreased acetylcholine (ACh), choline acetyltransferase (ChAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) as well as increased malondialdehyde (MDA) and protein carbonyls. In 3.5-month-old preplaque APPswe/PS1dE9 mice, correlational analyses revealed that the performance of impaired spatial memory was inversely correlated with soluble Aβ, MDA, and protein carbonyls, as well as being positively correlated with ACh, ChAT, SOD, and GSH-px; soluble Aβ level was inversely correlated with ACh, ChAT, SOD, and GSH-px, as well as being positively correlated with MDA and protein carbonyls; ACh level showed a significant positive correlation with ChAT, SOD, and GSH-px, as well as a significant inverse correlation with MDA and protein carbonyls. Collectively, this study provides direct evidence that increased oxidative damage and cholinergic dysfunction may be early pathological responses to soluble Aβ and involved in early memory deficits in the preplaque stage of AD. These findings suggest that early antioxidant therapy and improving cholinergic function may be a promising strategy to prevent or delay the onset and progression of AD.     

The variation of antioxidant defense system of Streptomyces sp. M4018 with respect to carbon sources

The effect of glycerol, glucose, and starch as carbon sources on the antioxidant defense system such as superoxide dismutase (SOD) and catalase (CAT) activities, pyruvate levels, and membrane lipid peroxidation (LPO) levels of Streptomyces sp. M4018, after isolation from the rhizosphere samples of Colutea arborescens and identification as a strain of S. hiroshimensis based on phenotypic and genotypic characteristics, were investigated. As an antioxidant defense enzyme, SOD activities increased up to 20 g/L of glycerol and 15 g/L of starch, while they showed negative correlation with glucose concentration. CAT activity variations of glycerol- and glucose-supplemented mediums showed significant positive correlations with the trend of SOD activities. However, CAT activity, in contrast to SOD, in Streptomyces sp. M4018 tended to decrease as the starch concentration increased. The production of pyruvate increased with respect to glycerol and starch up to 15 g/L, while it was positively correlated with glucose concentration. The highest pyruvate production was seen at 20 g/L glucose. Membrane LPO levels were negatively correlated with the activities of SOD and CAT enzymes, and the minimum LPO level was determined at 5 g/L of glucose, where SOD and CAT activities reached their maximum levels. Nevertheless, the higher SOD and CAT activities in a wider range of incubation period compared to the beginning by resulting in insignificant increases in membrane LPO levels showed the unusual antioxidant response capacities of the in Streptomyces sp. M4018 against the potentially deleterious effects of reactive oxygen species (ROS) for glycerol, glucose, and starch as carbon sources.     

棘孢木霉菌对钠胁迫的生理响应机制

【背景】棘孢木霉菌制剂被广泛应用于生物防治和次生盐渍化土壤的微生物修复,但是关于棘孢木霉在盐渍化胁迫条件下生长的耐盐机理及其富集盐离子的能力尚缺乏深入研究。【目的】揭示一株耐盐棘孢木霉菌(Trichodermaasperellum)CTCCSJ-W-SBW10264(T264)对钠胁迫的生理响应机制及其对钠离子的吸附和累积特性。【方法】设计梯度浓度钠胁迫培养实验,采集不同培养时期的菌丝样本,测定细胞氧化损伤相关指标H_2O_2和丙二醛(Malondialdehyde,MDA)的含量及细胞抗氧化相关酶的活性变化。【结果】钠胁迫实验表明,棘孢木霉T264能够在1.22mol/L的钠胁迫环境中生存,在低于0.25 mol/L的钠胁迫下其生长不会被明显抑制。细胞氧化损伤及氧化损伤响应相关指标的研究结果表明,培养液中钠离子浓度越高,棘孢木霉的膜系统氧化水平(MDA含量)越高,而且随着细胞中MDA和H_2O_2的累积,细胞抵御氧化损伤相关酶的活性也有明显提高,在钠盐处理24 h后,0.5、1.0和1.22 mol/L的钠离子胁迫分别使过氧化物酶(Peroxidase,POD)、超氧化物歧化酶(SuperoxideDismutase,SOD)和过氧化氢酶(Catalase,CAT)活性达到峰值,依次为36.66、3.34和233.3 U/mg。钠离子吸附和累积特性实验结果表明,棘孢木霉T264的菌丝对钠离子有强的吸附能力。在0.05 mol/L的钠离子环境中培养72 h后,菌丝表面钠离子吸附量为1 347.6 mg/g,菌丝内部钠离子累积量为218.6 mg/g,木霉菌菌丝通过菌丝表面吸附和菌丝内部累积对培养液中钠离子的去除率达到32%。【结论】T264的抗氧化损伤相关酶在其耐受钠离子胁迫过程中发挥重要作用,菌株T264对高浓度钠离子有强适应性,而且对环境中钠离子有高效的吸附和累积作用。     

Cyanobactericidal Effect of Streptomyces sp. HJC-D1 on Microcystis auruginosa

An isolated strain Streptomyces sp. HJC-D1 was applied to inhibit the growth of cyanobacterium Microcystis aeruginosa FACHB-905. The effect of Streptomyces sp. HJC-D1 culture broth on the cell integrity and physiological characteristics of M. aeruginosa FACHB-905 was investigated using the flow cytometry (FCM), enzyme activity and transmission electron microscopy (TEM) methods. Results showed that the growth of M. aeruginosa FACHB-905 was significantly inhibited, and the percentage of live cells depended on the culture broth concentration and exposure time. The activities of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) increased with exposure concentration and exposure time, and the significant increase of reactive oxygen species (ROS) led to the disruption of the subcellular structure of M. aeruginosa FACHB-905, and caused the increase of malondialdehyde (MDA). Furthermore, TEM observation suggested the presence of three stages (cell breakage, organelle release and cell death) for the cyanobactericidal process of Streptomyces sp. HJC-D1. Therefore, Streptomyces sp. HJC-D1 not only affected antioxidant enzyme activities and ROS level, but also destroyed the subcellular structure of M. aeruginosa FACHB-905, demonstrating excellent cyanobactericidal properties.     

铅锌胁迫下轮叶黑藻的吸附水平及生理响应

为探讨铅锌胁迫下轮叶黑藻(Hydrilla verticillate)的吸附水平及生理响应, 分别设置不同Pb2+(浓度梯度为0、0.01、0.05、0.10和0.20 mg/L)、Zn2+(浓度梯度为0、0.05、1.00、2.00和4.00 mg/L)浓度单一和复合胁迫轮叶黑藻28d, 测定其对铅锌的吸附量, 叶绿素a、叶绿素b、丙二醛(MDA)和总抗氧化能力(T-AOC)含量, 以及超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性变化。结果显示: 高浓度(≥1.00 mg/L)的Zn2+可促进轮叶黑藻对Pb2+的吸收, 对Zn2+的吸附主要受Zn2+处理浓度的影响; 低浓度Pb2+和Zn2+可以促进叶绿素的合成, 高浓度(浓度≥1.00 mg/L)胁迫则抑制叶绿素的合成; 受到胁迫时其抗氧化系统会迅速作出反应, 但一定浓度的Pb2+与Zn2+在单一和复合胁迫下, 抗氧化系统受限, 说明抗氧化系统不能正常运转, 机体受到损伤。研究结果为轮叶黑藻在重金属修复中的应用提供一定的理论依据。