Changes in Antioxidant Enzyme Activities and Malondialdehyde(MDA) Content of Rice with Blast Resistance Induced by Ag-antibiotic 702

The paper was to explore the effect of rice blast resistance induced by Ag-antibiotic 702 on antioxidant enzyme activities and malondialdehyde（ MDA）content. At three-leaf and one-heart stage of Luliangyou 996,15 μg/mL Ag-antibiotic 702 was sprayed,while Validamycin and distilled water were sprayed as positive control and negative control,respectively. The antioxidant enzyme（ SOD,POD,PPO,CAT and PAL） activities and malondialdehyde（ MDA） content in rice leaves were determined every 24 h within 168 h post spraying. Compared with CK,the MDA content and activities of the five antioxidant enzymes increased in Agantibiotic 702 treatment,Validamycin treatment and M. grisea inoculation treatment. The MDA content and SOD,CAT and POD activities in Ag-antibiotic 702 treatment were significantly higher than those in M. grisea inoculation treatment in early stage,and the APX and LOX activities increased more remarkably and rapidly. The induction effect of Ag-antibiotic 702 could reach or exceed that of Validamycin treatment. Ag-antibiotic 702 enhanced the resistance to rice blast because MDA content and antioxidant enzymes activities were improved in rice leaves. Therefore,the increase of rice blast resistance induced by Ag-antibiotic 702 in rice was positively correlated with the increase of MDA content and antioxidant enzymes activities in rice leaves.

PD-L1单抗加强紫杉醇联合香菇多糖体外抗人乳腺癌MDA-MB-231作用

目的 探讨程序性细胞死亡-配体1(PD-L1)单抗、紫杉醇(PTX)联合香菇多糖(LNT)体外对人乳腺癌细胞(MDA-MB-231)的作用。方法 将MDA-MB-231、人外周血单个核细胞(PBMC)和MDA-MB-231+PBMC共培养,随机分为对照组、PTX组、LNT组、MPDL3280A(PD-L1单抗)组、PTX+LNT组和PTX+LNT+MPDL3280A组。采用CCK8检测细胞的活性;流式细胞术检测MHC-I和PD-L1的表达;ELISA试剂盒检测IFN-γ和TNF-α的含量。结果 与对照组相比,PTX组、MPDL3280A组、PTX+LNT组及PTX+LNT+MPDL3280A组显著抑制MDA-MB-231的活性(P<0.01);LNT组和PTX+LNT+MPDL3280A组显著促进PBMC的免疫作用(P<0.05,P<0.01);PTX+LNT+MPDL3280A组显著抑制MDA-MB-231+PBMC共培养MDA-MB-231的活性(0.56±0.16 vs. 0.39±0.13,P<0.05);LNT显著促进MDA-MB-231上PD-L1的表达和PBMC分泌IFN-γ(P<0.05)。结论 PD-L1单抗通过阻断PD-L1与PD-1之间的作用,提高免疫,促进PTX联合LNT的体外抗三阴性乳腺癌作用。

Measurement of Malondialdehyde as a Biomarker of Lipid Oxidation in Fish

Oxidative reactions are key part of the stress response in marine organisms, which are exposed to a wide variety of environmental stressors. Lipid peroxidation (LPO) occurs in response to oxidant attack, giving rise to unsaturated aldehydes as malondialdehyde (MDA), the main biomarker for LPO assessment. Levels of MDA are measured in biological samples of different fish matrices to determine the oxidative effect of physical or chemical agents, particularly represented by metals. The most used assay is the spectrophotometric determination of thiobarbituric acid (TBA) as MDA-TBA2 adduct. Selectivity is enhanced by separating the adduct by chromatographic methods such as high-performance liquid chromatography or by using alternative derivatization reagents. Because, in biological organism, MDA is found free or protein bound, the two forms should be measured, and the extraction procedures are a crucial step in the processing of the biological sample. This review focused on MDA determination procedures used to assess the effect of experimental and environmental stress induced in fish.

烟草疫霉侵害对嫁接烟株叶片相关防御酶活性和MDA含量的影响

应用嫁接技术改善作物对病害的抗性已有成功的案例。为了探索烟草嫁接组合(嫁接烟株)在烟草疫霉(Phytophthora nicotianae)侵害下,叶片中主要相关防御酶活性、MDA含量的变化及其与嫁接烟株抗性的关系,以抗黑胫病品种P-KRK26和中感品种G279为砧木、感病品种红花大金元(红大)为接穗的嫁接烟株及自根苗为试验材料,通过盆栽接种烟草疫霉,分析了PAL、PPO、SOD、CAT、POD等防御酶活性和MDA含量的变化特点。结果表明:接种烟草疫霉后,接穗自根苗红花大金元(红大)、砧木自根苗P-KRK26、G279,以及嫁接组合P-KRK26+红大、G279+红大植株叶片中PAL、PPO、CAT、POD活性均有不同程度的升高,嫁接组合P-KRK26+红大、G279+红大叶片中防御酶的增加幅度多介于其接穗自根苗和砧木自根苗之间或显著大于自根苗。嫁接烟株叶片中SOD活性呈现先降低后升高的变化趋势,SOD酶在峰值时的下降幅度均显著小于其接穗自根苗和砧木自根苗。各处理烟草叶片中MDA含量均有不同程度的升高,嫁接烟株叶片MDA含量的增加幅度介于接穗自根苗和砧木自根苗之间。其中,嫁接烟株叶片的PPO、CAT活性的增加幅度与其对烟草疫霉侵害的抗性呈正相关,但嫁接烟株的抗性与PAL、POD、SOD活性和MDA含量的提高幅度并不相关,说明上述指标可能不是嫁接烟株抗病的直接因素。

Bioinformatics and Activity Analysis of Antioxidant Enzymes in Wheat Seedlings under Salt Stress and Their Malondialdehyde Content Changes

[Objectives]This study was conducted to improve crop yield and select excellent wheat varieties.[Methods]Wheat seedlings were treated with different concentrations of NaCl solution,and the activities of superoxide dismutase(SOD)and peroxidase(POD)and the content changes of malondialdehyde(MDA)in the leaves of seedlings were determined.A control group(distilled water)and three treatment groups(NaCl concentrations of 1,2 and 3 mmol/L)were set up.When the wheat seedlings grew to two leaves and one heart,they should be treated with different concentrations of NaCl solution(the wheat seedlings grew uniformly,and 20 ml of each NaCl concentration was used for treatment of wheat).When the wheat seedlings grew to four leaves and one heart under stress,samples were taken separately,once every 2 d,for three times,with 5 g of leaves each time.The SOD and POD activities and MDA content of seedlings in the control group and treatment groups were determined,and related protein sequences were analyzed by bioinformatics,including signal peptide prediction,transmembrane domain prediction,phosphorylation prediction and protein structure prediction.[Results]Under NaCl stress,the growth rates of seedling length and root length of wheat decreased obviously,and SOD and POD in leaves decreased,while the MDA content in leaves after treatment increased compared with the control group.SOD had no signal peptide,while POD had signal peptides and a transmembrane region.SOD and POD were different in terms of secondary and tertiary structures and the number of phosphorylation sites.[Conclusions]These results lays a solid theoretical foundation and application prospect for the study on salt tolerance mechanism of wheat seedlings in the later stage.

The Comparison of Contents of Malondialdehyde and Proline in the Area of Karst Area in Northweastern Guangxi Province

[Objective] To select excellent pioneer species of better ecological and economical comprehensive benefits from the common rock hill plants in Karst area in northwestern Guangxi Province.[Method] Determine the contents of malondialdehyde and proline in leaves of 65 strains of plants by thiobarbituric acid method and sultosalicylic acid method,analyze the relevance of the contents of malondialdehyde and proline by mathematics statistics and analyze the 65 kinds of rock hill plants by clustering [Result] The contents of malondialdehyde and proline are 0.005 2-0.038 1 μmol/g.There are comparably significant differences in the contents of malondialdehyde in different plants;The determination of proline contents in plant＇s leaves are 4.347-374.956 μg/ml.There are also significant differences in proline of different leaves of rock hill plants.The contents of malondialdehyde and proline can be used as a reference point in selecting pioneer plants in Karst area.But when we select the pioneer plants,not only the biological characters of the species themselves should be taken into consideration,but also the differences of Karst area environment,ecological and biological benefits and the reasonable distribution of species.[Conclusion] Pistacia chinensis,Zenia insignis,Acacia confusa,Itoa orientalis and Sophora japonica can be used as the first choices of excellent pioneer plants in Karst area in northwestern area which comparably consists with the real situation of afforestation of rock hills and recovery of plants in Guangxi.

糖尿病视网膜病变患者SDF-1、HO-1及MDA水平变化及与IL-6、TNF-α、CRP的相关性

目的 分析糖尿病视网膜病变(DR)患者基质细胞衍生因子(SDF-1)、血红素加氧酶-1(HO-1)及丙二醛(MDA)水平变化及与白介素-6(IL-6)、肿瘤坏死因子(TNF-α)、C反应蛋白(CRP)的相关性。方法 选取2020年5月至2023年1月解放军总医院收治的131例DR患者为DR组,另选取同期在本院住院的2型糖尿病患者100例为非DR组。比较两组SDF-1、HO-1、MDA水平;比较两组IL-6、TNF-α、CRP水平;比较不同分期DR患者SDF-1、HO-1、MDA水平;采用Logistic回归分析影响DR发生的相关因素,分析DR组患者SDF-1、HO-1、MDA水平与IL-6、TNF-α、CRP的相关性。结果 DR组SDF-1、HO-1水平比非DR组低,MDA水平比非DR组高,差异有统计学意义(P<0.05);DR组IL-6、TNF-α、CRP水平均比非DR组高,差异有统计学意义(P<0.05);SDF-1、HO-1水平:Ⅰ~Ⅱ期>Ⅲ~Ⅳ期>Ⅴ~Ⅵ期,MDA水平:Ⅰ~Ⅱ期<Ⅲ~Ⅳ期<Ⅴ~Ⅵ期,差异有统计学意义(P<0.05);经Logistic多因素分析显示,性别为女、BMI≥24 km/m2、合并患有高血压、高血脂、IL-6>1.17 mg/mL、TNF-α>30 ng/L、CRP>10 ng/mL、SDF-1>2 ng/mL、HO-1<125 ng/mL、MDA>4.06μmol/mL均是影响DR发生的独立危险因素(P<0.05);血清炎性因子IL-6、TNF-α、CRP与SDF-1、HO-1呈负相关,与MDA呈正相关,且均为中度相关(P<0.05)。结论 SDF-1、HO-1、MDA、IL-6、CRP、TNF-α水平与DR的发生、发展有一定关系,通过检测上述指标水平可为进一步探讨DR的发病机制和治疗方法提供新的思路。

不同预后的抗MDA5抗体阳性IIMs患者肺部HRCT定量指标与临床研究

目的:比较分析不同预后的抗黑色素瘤分化相关基因5(MDA5)抗体阳性特发性炎性肌病(IIMs)患者的肺部HRCT定量指标与临床表现。方法:回顾性分析2017年2月至2022年11月首都医科大学附属北京世纪坛医院收治的19例MDA5抗体阳性IIMs患者的临床及影像学数据,将患者按预后不同分为预后良好组(14例)及预后不良(插管或死亡)组(5例),比较两组患者的临床及实验室指标、间质性肺病(ILD)类型及CT量化指标。结果:预后良好及不良组患者在性别、癌胚抗原、血氧饱和度、淋巴细胞百分比、单核细胞百分比、中性粒细胞百分比、淋巴细胞、中性粒细胞水平上差异具有统计学意义。预后不良组出现呼吸系统异常改变的比例更高。在ILD类型方面,预后不良组患者以急性间质性肺炎(AIP)样病变为主、预后良好组患者以非特异性间质性肺炎(NSIP)样病变为主,两组存在统计学差异。预后不良组半定量评分更高,全肺病灶体积更高且全肺病灶占比更高差异具有统计学意义。Spearman相关分析结果显示,血氧饱和度、单核细胞百分比与半定量评分、全肺病灶体积及全肺病灶占比呈负相关,癌胚抗原、中性粒细胞百分比、中性粒细胞与半定量评分、全肺病灶体积及全肺病灶占比呈正相关。结论:不同预后的MDA5抗体阳性IIMs患者的肺部HRCT定量指标、临床表现及实验室指标有差异,为临床诊疗提供了相应支持。

补肾活血汤及其拆方对MDA-MB-231乳腺癌细胞增殖、迁移、侵袭能力及其CXCR4表达的影响

目的探讨补肾活血汤及其拆方组(补肾组、活血组)对人乳腺癌MDA-MB-231细胞增殖、迁移、侵袭能力及CXCR4蛋白表达的影响。方法分别以补肾活血汤(1.23 g/mL、1.845 g/mL、2.46 g/mL)、补肾中药(0.873 g/mL、1.31 g/mL、1.746 g/mL)、活血中药(0.36 g/mL、0.54 g/mL、0.72 g/mL)汤剂灌胃SD雄性大鼠,制备含药血清。以乳腺癌细胞MDA-MB-231为研究对象,分为对照组,补肾活血汤高、中、低浓度组,补肾中药高、中、低浓度组,活血中药高、中、低浓度组,紫杉醇组。采用MTT法探究上述各组MDA-MB-231细胞增殖活力;细胞划痕试验、Transwell小室侵袭实验检测对照组、补肾活血汤高浓度组、补肾中药高浓度组、活血中药高浓度组、紫杉醇组MDA-MB-231细胞迁移、侵袭能力;Western blot法检测各组高浓度药物对MDA-MB-231细胞中CXCR4蛋白表达的影响。结果与对照组比较,补肾活血汤低、中、高浓度,补肾中药中、高浓度,活血中药中、高浓度以及紫杉醇可显著抑制MDA-MB-231细胞增殖活性;补肾活血汤高浓度、活血中药高浓度、补肾中药高浓度和紫杉醇均显著抑制MDA-MB-231细胞迁移、侵袭能力(P<0.05或P<0.01)和CXCR4蛋白表达水平(P<0.05),其中,补肾活血汤高浓度组和紫杉醇组效果更佳(P<0.05)。结论补肾活血汤可抑制人乳腺癌MDA-MB-231细胞的增殖、侵袭、迁移能力,可能与下调MDA-MB-231细胞表面CXCR4蛋白表达水平相关。

Mapping of QTLs for Leaf Malondialdehyde Content Associated with Stress Tolerance in Rice

Malondialdehyde （MDA） is the final product of lipid peroxidation, and MDA content can reflect the stress tolerance of plants. To map QTLs conditioning the MDA content in rice leaves, a recombinant inbred line （RIL） population with 247 lines derived from an indica-indica cross Zhenshan 97BxMilyang 46, and a linkage map consisting of 207 DNA markers were used. The RIL population showed a transgressive segregation in the MDA content of rice leaves. Two QTLs for the MDA content in rice leaves were detected in the intervals RG532-RG811 and RG381-RG236 on chromosome 1, with the additive effects from maternal and paternal parents, accounting for 4.33% and 4.62% of phenotype variations, respectively.

Changes of c-fos, Malondialdehyde and Lactate in Brain Tissue after Global Cerebral Ischemia under Different Brain Temperatures

Summary： Under global cerebral ischemia, the effect of different brain temperature on cerebral ischemic injury was studied. Male Sprague-Dawley rats were divided into normothermic （37-38℃） ischemia, mild hypothermic （31 32℃） ischemia, hyperthermic （41-42℃） ischemia and sham-operated groups. Global cerebral ischemia was established using the Pulsinelli four-vessel occlusion model and brain temperature was maintained at defined level for 60 min after 20omin ischemia. The expression of c-fos protein and the levels of malondialdehyde （MDA） and lactate in brain regions were detected by immunochemistry and spectrophotometrical methods, respectively. C-fos positive neurons were found in the hippocampus and cerebral cortex after cerebral ischemia reperfusion. Mild hypothermia increased the expression of c-fos protein in both areas, whereas hyperthermia decreased the expression of c-los protein in the hippocampus at 24 h reperfusion, and the cerebral cortex at 48 h reperfusion when compared to normothermic conditions. In normothermic, mild hypothermic and hyperthermic ischemia groups, the levels of MDA and lactate in brain tissue were increased at 24, 48 and 72 h reperfusion fol- lowing 20-min ischemia as compared with the sham-operated group （P〈0.01）. The levels of MDA and lactate in mild hypothermic group were significantly lower than those in normothermic group （P〈0.01）. It is suggested that brain temperature influences the translation of the immunoreactive protein product of c-fos after global cerebral ischemia, and MDA and lactate are also affected by hypothermia and hyperthermia.

子痫前期患者血清MDA、TMAO、PLGF的水平变化及诊断价值

目的探讨子痫前期患者血清丙二醛(MDA)、氧化三甲胺(TMAO)、胎盘生长因子(PLGF)的水平变化及诊断价值。方法选取2020年10月至2022年10月唐山市妇幼保健院收治的75例子痫前期患者作为研究组,选取同期体检的75例健康孕妇作为对照组。采用酶联免疫吸附试验法检测两组血清MDA、TMAO、PLGF水平,根据病情程度将子痫前期患者分为轻度子痫前期组(n=50)和重度子痫前期组(n=25)。比较对照组和研究组、轻度子痫前期组和重度子痫前期组血清MDA、TMAO、PLGF水平,采用Logistic回归分析子痫前期病情严重程度的影响因素,采用受试者工作特征(ROC)曲线分析血清MDA、TMAO、PLGF水平对子痫前期的诊断价值。结果研究组收缩压、舒张压、24 h尿蛋白水平均高于对照组(P<0.05)。研究组血清MDA、TMAO水平均高于对照组,血清PLGF水平低于对照组(P<0.05)。重度子痫前期组血清MDA、TMAO水平均高于轻度子痫前期组,血清PLGF水平低于轻度子痫前期组(P<0.05)。Logistic回归分析结果显示,MDA、TMAO是子痫前期重度的危险因素(P<0.05),PLGF是子痫前期重度的保护因素(P<0.05)。血清MDA、TMAO、PLGF三者联合诊断效能高于各指标单独诊断(P<0.05)。结论子痫前期患者血清MDA、TMAO水平显著升高,PLGF水平显著降低,三者联合诊断效能高于各指标单独诊断。

豪洛捷乳腺结节真空旋切术对乳腺结节患者5-HT MDA及TNF-α的影响

目的:探讨豪洛捷乳腺结节真空旋切术对乳腺结节患者神经递质5-羟色胺(5-hydroxytryptamine,5-HT)、丙二醛(Malondialdehyde,MDA)及肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)的影响。方法:回顾性分析择取2020年4月至2023年5月期间,本院收治的乳腺结节患者148例,经纳入、排除标准剔除46例病例,最终纳入102例病例,依据手术方式不同分为对照组(n=50,传统小切口术治疗)及实验组(n=52,豪洛捷乳腺结节真空旋切术治疗)。对比两组手术观察指标、治疗前后5-HT、MDA及TNF-α水平变化、术后恢复良好率、并发症发生率及结节复发率。结果:与对照组相比较,实验组切口长度更短,术后住院天数、失血量更少,手术总时长更短(P<0.05)。治疗前至治疗后3d的5-HT、MDA及TNF-α水平均上升,治疗后3d至治疗后7d的5-HT、MDA及TNF-α水平均下降(P<0.05),且在治疗后1d、3d、7d时,实验组5-HT、MDA及TNF-α水平比对照组低(P<0.05)。对照组、实验组恢复良好率分别为78.00%、92.31%,实验组恢复良好率更高(P<0.05)。两组结节复发率比较,差异无统计学意义(P>0.05),实验组并发症发生率(5.76%)比对照组(20.00%)低(P<0.05)。结论:豪洛捷乳腺结节真空旋切术对乳腺结节患者5-HT、MDA及TNF-α水平影响相对较小,且并发症发生率低,在促进患者术后早期康复中有积极作用。

Increased plasma malondialdehyde and fructosamine in anemic H pylori infected patients:Effect of treatment

AIM： TO unravel the possible association of malondialdehyde （MDA） and fructosamine in anemic H pylori infected patients and to observe the alteration in MDA and fructosamine levels in these patients after treatment for one month. METHODS： Fructosamine, MDA and glucose were estimated in 22 anemic H pylori infected patients and 16 healthy controls. Hematological parameters were also evaluated in both the groups using Sysmex-K-100 automated cell counter. The H pylori infected patients were randomly divided into two groups. Hpylori infected patients in Group Ⅰ received both iron supplementation and anti-H pylori therapy, while patients in Group Ⅱ received only iron supplementation. All the biochemical and hematological parameters were estimated after one month of treatment. RESULTS： In anemic H pylori infected patients, while MDA （5.41 ± 2.16 vs 2.26 ± 0.50; P 〈 0.05） and fructosamine （2.64 ± 0.93 vs 1.60 ± 0.35; P 〈 0.05） were significantly increased, iron （32.72 ± 14.93 vs 110.25 ± 26.58; P 〈 0.05）, hemoglobin （6.9 ± 2.6 vs 12.66 ± 0.74; P 〈 0.05） and ferritin （28.82 ± 16.27 vs 140.43 ± 30.72; P 〈 0.05） levels were significantly decreased compared with the controls. With partial correlation analysis, fructosamine was found to have a significant positive correlation with MDA. In Group I, while MDA level decreased significantly （3.11 ± 1.73 vs 5.50 ± 2.46; P 〈 0.05）, there was a significant increase in iron （84.09 ± 29.51 vs 36.09 ± 17.81; P 〈 0.05）, hemoglobin （10.40 ± 1.11 vs 7.42 ± 1.90; P 〈 0.05） and ferritin （116.91 ± 63.34 vs 30.46 ± 17.81; P 〈 0.05） levels after one month. There was no significant change in the levels of fructosamine in group Ⅰ after treatment. Similarly, no significant alterations were noted in the levels of IDA, fructosamine, hemoglobin or ferritin in Group Ⅱ patients after one month of treatment. CONCLUSION： An increased level of fructosamine and MDA was found in anemic H pylori infected patients. Present data supports the premise that lipid peroxides per se do play a role in the glycation of plasma proteins. Furthermore, the findings from this study indicate that treatment for both anemia and H pylori infections is required for lowering the levels of lipid peroxides in these patients.

Effect of in ovo ghrelin administration on serum malondialdehyde level in newly-hatched chickens

Objective:To investigate effects of in ovo ghrelin administration on serum malondialdehyde(MDA)level in newly-hatched chickens.Methods:Fertilized eggs were divided into 7 groups:group Tl as control(without injection),group T2(in ovo injected with 50 ng/egg ghrelin on day 5),group T3(in ovo injected with 100 ng/egg ghrelin on day 5),group T4(in ovo injected with 50 ng/egg ghrelin on day 10),group T5(in ovo injected with 100 ng/egg ghrelin on day 10),group T6(in ovo injected with solvent:1%acetic acid,without ghrelin on day 5)and group T7(in ovo injected with solvent without ghrelin on day 10).After hatching,serum MDA concentrations were determined.Results:Chrelin administrated groups(T2,T3,T4 and T5)had lower serum MDA level in comparison with control group(T1)or solvent injected groups(T6 and T7).T2 and T3(ghrelin injection on day 5)had significantly lower MDA concentrations(4.10 and 4.60 nmol/mL,respectively)in comparison with other groups.In T4 and T5,MDA levels were lower than T1,T6 and T7(non-ghrelin administrated groups)(9.53 and 9.50 in comparison with 10.73,10.03 and 10.13 nmol/mL)and were higher than T2and T3.Conclusions:It can be concluded that in ovo administration of ghrelin can have antioxidative protection and reduce serum MDA level.Ghrelin administration on day 5 of incubation is more efficient.

Regulation of Content of Malondialdehyde by Siqi Decoction via Increasing Activity of Superoxide Dismutase in Blood Serum of Rats with Myocardial Ischemia

Effect of Siqi decoction on myocardial ischemia is to prevent cardiac myocyte membrane from damage associated with oxygen free radicals related to NO. To research the regulatoin of the content of malondialdehyde by Siqi decoction, an index of lipid peroxidation, via increasing activity of superoxide dismutase in blood serum of rats with Myocardial Ischemia, the model of myocardium ischemia was made in Wistar rats with posterior pituitary injection through vein in tail. Siqi decoction, Diaoxinxuekang（DK） and Fufangdanshenpian（FD）, the latter two drugs of which are effective TCM drugs of anti-myocardial ischemia at present, were administrated to the rats with myocardium ischemia for 5 days to compare the effect of them on myocardium ischemia as reference drugs via measuring the changes of the content of malondialdehyde and the activity of superoxide dismutase in the rat blood serum with myocardial ischemia. There were a remarkable increase in the activity of superoxide dismutase and a decrease in the content of malondialdehyde in the serum of the rats administered Siqi decoction compared with those of the rats in control group, p〈0.05. The contents of MDA in the serum of the prevention group rats in the experiments are lower than those of the cure group rats. Anti-Myocardium Ischemia mechanism of Siqi decoction is the regulation of the content of malondialdehyde via increasing activity of superoxide dismutase in the serum of Rats with myocardial ischemia and stimulating the activity of NOS in serum so as to increase NO concentration.

αB-crystallin malondialdehyde,superoxide dismutase, and lutathione peroxidase changes in X-ray irradiated rat lens

AIM: To evaluate αB-crystallin malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) changes in X-ray irradiated rat lens. METHODS: Eight-week-old Sprague-Dawley male rats received X-ray irradiation to the head with rest of the body protected. The exposure dose ranged from 2 to 25 Grays (Gy). The cataract status were examined by slit lamp and rated with 'four-grade systems' post-irradiation. The lens MDA level, and the activities of SOD and GPx were measured in a short-term experiment post-irradiation, and αB-crystallin protein levels were quantified. RESULTS: The lenses of normal control and the X-ray irradiated groups with the dose up to 10 Gy remained transparent throughout the experiment. The lens first appeared tiny scatters, and even lamellar opacities in the posterior capsule 45 days post-irradiation with the dose of 15 Gy, and progressed slowly to the advance stage of cataract; while, for the higher dose (25 Gy), the opacity of lens appeared much earlier, and progressed more rapidly to mature stage of cataract within 1 month. At the end of the observation (90 days post-irradiation), almost all lenses became complete opacity with the higher dose (25 Gy). The degree of lens opacity was rated accordingly. The lens MDA level was increased, and SOD and GPx activities were decreased with a dose-dependent manner post-irradiation. The αB-crystallin protein level was decreased dose-dependently at the end point of observation. CONCLUSION: Oxidative events and αB-crystallin may play important roles in the pathogenesis of cataract in X-ray irradiated rat lens.

Variations of antioxidant enzyme activity and malondialdehyde content in nemertean Cephalothrix hongkongiensis after exposure to heavy metals

The antioxidant enzyme activity and malondialdehyde(MDA) content of Cephalothrix hongkongiensis were studied to assess variations in the biochemical/physiological parameters of nemerteans under heavy metal stress.Worms were exposed to copper,zinc and cadmium solutions at different concentrations,and the activity of three antioxidant enzymes,catalase(CAT),superoxide dismutase(SOD),and glutathione peroxidase(GPX),and MDA content were measured.The results show that the activity of each enzyme changed immediately after exposure to heavy metals.CAT was invariably inhibited throughout the experimental period,while the SOD activity was significantly elevated by exposure to Cu^(2+) for 48h,but then decreased.SOD was inhibited by Zn^(2+) during the first 12h of exposure,but activated when exposed for longer periods.Under Cd^(2+) stress,SOD activity decreased within 72h.GPX activity varied greatly,being significantly increased by both Cu^(2+) and Zn^(2+),but significantly inhibited by Cd^(2+) in the first 12-24h after exposure.MDA content increased on Cu^(2+) exposure,but normally decreased on Zn^(2+) exposure.MDA content followed an increase-decrease-increase pattern under Cd^(2+) stress.In conclusion,the antioxidant system of this nemertean is sensitive to heavy metals,and its CAT activity may be a potential biomarker for monitoring heavy metal levels in the environment.

Protective effect of melatonin against multistress condition induced lipid peroxidation via measurement of gastric mucosal lesion and plasma malondialdehyde levels in rats

AIM： To study the protective effect of a natural antioxidant, melatonin, against multistress condition induced lipid peroxidation v/a determination of gastric damage and plasma malondialdehyde （MDA） level by high performance liquid chromatography in rats. METHODS： We compared indomethacin-induced gastric damage and MDA plasma level in three groups of rats： unoperated, bile duct ligated and sham-operated and evaluated the role of the melatonin on gastric damage and plasma MDA level. Indomethacin and melatonin were injected intraperitoneally in doses of 50 mg/kg and 20 mg/kg, respectively. Animals were killed 4 h after indomethacin injection. RESULTS： Indomethacin induced more severe gastric damage and plasma MDA level in bile duct ligated animals was significantly higher （3.1±0.04 μmol/L） than sham （2.8±0.04 μmol/L） and unoperated animals （1.4±0.08 μmol/L）. Pretreatment with melatonin reduced indomethacin-induced gastric damage and plasma MDA level. CONCLUSION： Considering the results of this study, we suggest that in multistress conditions the intensity of gastric damage and the plasma MDA level are great and melatonin reduces the negative effect of lipid peroxidation and cell damage by oxidative stress in multistress conditions due to its antioxidizing activity.

Oxidative modification of malondialdehyde influences the structure and emulsification properties of egg yolk high-density lipoprotein

Malondialdehyde(MDA)represents secondary active oxidation products in lipid peroxidation.This research used MDA to establish a simulated oxidation system to study its effects on egg yolk high-density lipoprotein(EYHDL)structure and emulsifying properties.It was shown that incubation of EYHDL with MDA resulted in protein carbonylation and a gradual reduction in the sulfhydryl content.Fourier transform infrared spectroscopy(FT-IR),and fluorescence spectroscopy indicated that MDA oxidation would destroy the ordered structure of EYHDL and the structural stability of the protein.Oxidation might result in the intermolecular cross-linking of EYHDL and the formation of oxidized aggregates,leading to a reduction in surface hydrophobicity.For the EYHDL emulsion modified by MDA oxidation,it could be seen that the emulsion stratification was evident at the macroscopic level,and the grain diameter of the EYHDL emulsion was observed to increase with the MDA concentration by inverted fluorescence microscopy.The emulsification activity(EAI)and emulsification stability(ESI)of EYHDL were decreased by malondialdehyde oxidation modification,which may be due to the decrease of protein surface hydrophobicity and oxidation aggregation.