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Cui-Yun YangSu-Jing Liu Shi-Wei ZhouHui-Feng Wu Jun-Bao YuChuan-Hai Xia 《Pesticide biochemistry and physiology》2011,100(1):93-103
Ethyl 2-methyl acetoacetate (EMA) is a novel allelochemical exhibiting inhibitory effects on the growth of marine unicellular alga Phaeodactylum tricornutum (P. tricornutum). Oxidative damage and antioxidant responses in P. tricornutum were investigated to elucidate the mechanism involved in EMA inhibition on algal growth. The increase in reactive oxygen species (ROS) levels and malondialdehyde (MDA) contents following exposure to EMA suggested that alga was suffered from oxidative stress and severely damaged. The decrease in cell activity and cellular inclusions suggested that cell growth was greatly inhibited. The activities of the antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxide (GSH-PX) and glutathione S-transferase (GST) increased with the exposure concentration and decreased with the prolongation of exposure time. Cellular ascorbic acid (AsA) and reduced glutathione (GSH) systems were also involved in resisting oxidative stress of EMA by altering the composition of AsA and GSH pools. EMA exposure increased the contents of AsA, GSH, dehydroascorbate (DAsA) and glutathione (GSSG). However, the regeneration rate of AsA/DAsA did not change obviously between treatments and the control, while that of GSH/GSSG decreased significantly under 14 mmol/L EMA exposure on the 3rd day. These results showed that EMA-induced oxidative damage might be responsible for EMA inhibition on P. tricornutum growth and cellular antioxidant enzymes and non-enzymatic antioxidants were improved to counteract the oxidative stress. 相似文献
994.
Jalal Pourahmad Mir-Jamal HosseiniSoudeh Bakan Mahmoud Ghazi-Khansari 《Pesticide biochemistry and physiology》2011,99(1):105-110
Paraquat is a highly toxic herbicide that is used in most countries without restriction. The cytotoxic action of paraquat is mediated by reactive radicals that are products of its metabolic reduction in cells. It has already been hypothesized that some angiotensin-converting enzyme inhibitors (e.g., captopril and enalapril) could show antioxidant and radical scavenging activity through their structural thiol groups, increasing antioxidant enzymes production or nitric oxide synthesis. In this study the hepatoprotective effect of captopril and enalapril against paraquat induced oxidative stress cytotoxicity was evaluated in isolated rat hepatocyte. Subtoxic concentrations of captopril (0.2 mM) and enalapril (0.2 mM) significantly (p < 0.05) protected the hepatocytes against paraquat (2 mM) induced oxidative stress cytotoxicity markers including: cell lysis, reactive oxygen species (ROS) generation, lipid peroxidation, glutathione depletion, mitochondrial membrane potential decrease, lysosomal membrane oxidative damage and cellular proteolysis. Moreover, we showed that non-thiol enalapril acts as well as thiol containing captopril at inhibiting oxidative stress cytotoxicity markers. Finally, our results support the hypothesis that it is the increase in nitric oxide synthesis and not the presence of the thiol group that accounts for the antioxidant activity of ACE inhibitors. 相似文献
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[目的] 对红蓼种子乙酸乙酯萃取物中具有潜在杀虫活性的化合物进行初步分析,为指导开发利用杀虫植物资源提供依据。[方法] 采用硅胶柱层析和气相色谱 质谱(GC MS)联用法,以5龄黏虫为试虫;对红蓼种子萃取物的有效杀虫活性成分进行分析,应用色谱峰面积归一法测定各组分的相对百分含量。[结果] 极性(甲醇)组分共分离出37个色谱峰,鉴定了其中的35个组分,占总含量的94.46%。弱极性(二氯甲烷)组分共分离出39个色谱峰,鉴定出39个组分。[结论] 从成分的化学结构推断,红蓼种子的杀虫活性可能存在于14种成分中,主要成分为酮、醇、开环萜和五环三萜烷类化合物。 相似文献
998.
芳氧苯氧基丙酸酯类除草剂的应用进展 总被引:2,自引:0,他引:2
芳氧苯氧基丙酸酯(简称APP)类除草剂是近二十年发展起来的活性很好的新型除草剂,用于防除一年或多年生禾本科杂草。本文主要综述了APP的发展历史、作用机理、主要品种以及应用研究进展。 相似文献
999.
鸵鸟主要性激素分泌规律的研究 总被引:2,自引:2,他引:0
本研究旨在观察鸵鸟一年中激素分泌规律与发情行为的相关性,为采精和输精掌握最准确的时间,采用放射免疫分析法(RIA)测定样品中促卵泡刺激素(FSH)、雌激素(E2)和睾酮(T)的浓度水平。结果表明:①雌鸵鸟血浆内FSH水平在一年之中呈现波动式变化,从11月开始上升,12、2、7月中出现3个明显的分泌波峰,峰值分别为114.354、130.168和144.375 mIU/mL,6月中旬达到全年中最低22.312 mIU/mL;②E2水平在1~5月都呈缓慢上升趋势,在7月突然下降到最低(18.874 pg/mL),9月达全年最高峰(367.285 pg/mL);③雄鸵鸟血浆睾酮(T)浓度从1~6月一直呈上升趋势,6月达到较高水平(121.473 ng/dL),8月达到全年中最低(77.166 pg/dL),到10月中旬达到全年最高(138.562 ng/dL);鸵鸟血浆内FSH、E2及T的浓度水平在一年之中呈现波动式变化与发情表现趋于一致。 相似文献
1000.