氟化氢对植物叶片中SOD酶活力和MDA含量的影响

本文研究了浓度为０．０４１ｍｇ／ｍ￣３，０．０８３ｍｇ／ｍ￣３和０．１６６ｍｇ／ｍ￣３的ＨＦ气体分别对小麦、玉米和蚕豆三种植物熏气后，植物叶片中ＳＯＤ酶活力的变化及膜脂过氧化产物ＭＤＡ含量的变化，实验结果表明高深度ＨＦ（０．１６６ｍｇ／ｍ￣３）对ＳＯＤ有抵制作用，较低浓度（０．０８３ｍｇ／ｍ￣３，０．０４１ｍｇ／ｍ￣３）下是先升后抑。在三种浓度下，叶片中ＭＤＡ含量均随熏气时间的延长而增加。三种植物对氟化氢的敏感性不同，由大到小依次为蚕豆、小麦、玉米。     

猴头子实体锰型超氧物歧化酶的纯化及其性质鉴定

猴头子实体的超氧物歧化酶仅Ｍｎ－ＳＯＤ１种,有其资源和学术研究上的意义。其粗酶液经（ＮＨ４）２ＳＯ４盐析,ＤＥ５２和ＣＭ５２离子交换柱层析,纯化到电泳单斑点均一程度,其比活性为３０９６．５ｕ／ｍｇ,活性回收率为１４．８％。纯化的Ｍｎ－ＳＯＤ分子量为４７．０ＫＤ,亚基分子量为２３．３ＫＤ。金属元素分析表明每个亚基含１个Ｍｎ原子。该酶在紫外区有２个吸收峰,分别在２１８．４ｎｍ和２７６．０ｎｍ。该酶的理     

16种伞形科药用植物对超氧自由基的清除作用

采用Ｎａ２Ｓ２Ｏ４ＮａＯＨＬｕｍｉｎｏｌ发光体系,应用智能化学发光法对１６种伞形科药用植物提取物的自由基清除能力和对酪氨酸酶的抑制能力进行筛选。实验结果表明这些伞形科药用植物大都具有清除自由基的作用,其中羌活（ＮｏｔｏｐｔｅｒｙｇｉｕｍｆｏｒｂｅｓｉｄｅＢｏｉｓ．）的“ＳＯＤ样作用”达到２９６７Ｕ／ｍｇ（原生药量）,提示这些植物具有稳定的非酶类清除自由基物质,并且“ＳＯＤ样作用”强弱与其对酪氨酸酶的抑制能力呈明显正相关。     

纯化超氧化物歧化酶的新工艺

为探索简便实用纯化ＳＯＤ的工艺路线,以人或猪血红细胞溶血上清液,经铜胺中空纤维透析器（分子量截留值为１５ｋＤ）透析和超滤,收集分子量大于１５．０ｋＤ的物质,再加热６０℃１０ｍｉｎ,离心取上清即得。Ｃｕ、ＺｎＳＯＤ和ＭｎＳＯＤ分子量分别为３２．０ｋＤ和８０．０ｋＤ。人血和猪血纯化的ＳＯＤ总收率分别为８８．２％和８９．２％,比活性分别为１７４２９Ｕ／ｍｇ和１８２２８Ｕ／ｍｇ。工艺简便实用,适于工业纯化生产。     

水杨酸对黄瓜叶片抗氧化剂酶系的调节作用

分析了水杨酸（ＳＡ）对黄瓜（ＣｕｃｕｍｉｓｓａｔｉｖｕｓＬ．）叶片抗氧化剂酶系活性及活性氧水平的调节作用。不同浓度的ＳＡ（０．５ｍｍｏｌ／Ｌ、１ｍｍｏｌ／Ｌ、２．５ｍｍｏｌ／Ｌ、５ｍｍｏｌ／Ｌ）均能显著地提高被处理叶片超氧化物歧化酶（ＳＯＤ）和过氧化物酶（ＰＯＤ）活性,而且还能诱导同株的非处理叶片中ＳＯＤ和ＰＯＤ活性增加。用１ｍｍｏｌ／ＬＳＡ处理第一片真叶,在处理后６～７２ｈ,ＰＯＤ活性增加了２２％～６７％,同株非处理的第二片真叶ＰＯＤ活性增加了１４％～８６％,但是,在ＳＡ处理后３ｈ之前以及处理９６ｈ之后,ＰＯＤ活性没有变化。ＳＡ能够显著降低超氧物阴离子含量和提高过氧化氢水平,但它对过氧化氢酶（ＣＡＴ）活性的抑制作用很弱,表明ＳＡ提高体内过氧化氢含量的原因主要是通过提高ＳＯＤ活性而不是抑制ＣＡＴ活性。同工酶分析表明,ＳＡ不能诱导新的ＳＯＤ同工酶,但可以诱导新的ＰＯＤ同工酶。     

超氧化物歧化酶全酶和脱辅基酶胍变性时失活与去折叠的比较研究

利用紫外差吸收光谱和荧光发射光谱等监测手段研究天然铜锌ＳＯＤ（ｈｏｌｏ－ＳＯＤ）和脱铜锌ＳＯＤ（ａｐｏ－ＳＯＤ）在不同浓度胍溶液中的去折叠及活力变化．结果表明ｈｏｌｏ－ＳＯＤ和ａｐｏ－ＳＯＤ分别在４．０和２．０ｍｏｌ／Ｌ胍溶液中去折叠,而分别在２．０和０．５ｍｏｌ／Ｌ胍溶液中其构象尚未发生明显改变时活性几乎完全丧失．提示金属离子对维持酶的整体及活性部位构象具有重要作用,脱去金属离子的酶分子的构象特别是活性部位的构象更易受到变性剂的破坏．     

水分亏缺下乙酰水杨酸清除小麦幼苗中O_2~的研究(简报)

通过体外ＮＢＴ光化还原系统证明,乙酰水杨酸（ＡＳＡ） 有直接清除Ｏ－·２ 的作用。ＡＳＡ 浓度大于１５０ ｍｇ·Ｌ－ １ 时可完全清除体系内的Ｏ－·２ 。水分亏缺下,０ ．０５ ％ ＡＳＡ 明显降低小麦幼苗中Ｏ－·２ 的含量。ＡＳＡ 既有直接清除Ｏ－·２ 的作用,又可通过提高ＳＯＤ 活性来清除Ｏ－·２ 。     

生长抑素对羟自由基损伤的人胃粘膜上皮细胞系GES—1的影响

目的和方法：采用人胃粘膜上皮细胞系ＧＥＳ１细胞传代培养技术,利用Ｆｅ２＋与Ｈ２Ｏ２反应生成的羟自由基（ｈｙｄｒｏｘｙｌｒａｄｉｃａｌ,ＯＨ·）建立细胞损伤模型,探讨ＯＨ·损伤人胃粘膜细胞的机制,观察生长抑素（ｓｏｍａｔｏｓｔａｔｉｎ,ＳＳ）对ＧＥＳ１细胞抗ＯＨ·损伤的影响。结果：（１）ＯＨ·可直接损伤ＧＥＳ１细胞,表现为细胞存活率下降而细胞乳酸脱氢酶（ｌａｃｔａｔｅｄｅｈｙｄｒｏｇｅｎａｓｅ,ＬＤＨ）漏出量增多;预先在细胞培养液中加入ＯＨ·特异性清除剂二甲基亚砜（５ｍｍｏｌ／Ｌ）,可预防该损伤。预先加入ＳＳ（０．０１ｍｇ／Ｌ,０．１ｍｇ／Ｌ,１．０ｍｇ／Ｌ,１０ｍｇ／Ｌ）对细胞存活率和细胞ＬＤＨ漏出量无影响;（２）加入ＯＨ·后,细胞丙二醛（ＭＤＡ）、氧化型谷胱甘肽（ＧＳＳＧ）含量上升而还原型谷胱甘肽（ＧＳＨ）含量下降。以ＳＳ０．１ｍｇ／Ｌ,１．０ｍｇ／Ｌ,１０ｍｇ／Ｌ预处理,可部分减轻上述改变。结论：ＯＨ·可直接损伤ＧＥＳ１细胞,其机制与破坏细胞的巯基稳态及加重细胞的脂质过氧化程度有关;ＳＳ可通过维持细胞的巯基稳态,部分减轻ＯＨ·所致的ＧＥＳ１细胞脂质过氧化程度。     

兔迷走复合区内微量注射TRH对奥迪氏括约肌肌电的影响及传出途径分析

目的和方法：本工作旨在研究免迷走复合区（ＤＶＣ）内ＴＲＨ对奥迪氏括约肌（ＳＯ）肌电的调节作用及外周途径。结果：（１）ＤＶＣ内注射ＴＲＨ（０．８ｎｍｏｌ,１μｌ）后,慢波电位（ＳＷ）频率不变,但锋电位频率（ＦＳＰＳＯ）及幅度（ＡＳＰＳＯ）、锋电位发生率（ＩＳＰ）明显增加．（２）ＤＶＣ内分别注射不同剂量ＴＲＨ（０．１３,０．２５,０．５０,０．８０,１．３０ｎｍｏｌ,１μｌ）后,各剂量ＴＲＨ均能引起ＦＳＰＳＯ增加。随注射剂量的增加,ＳＯ反应强度和持续时间均增加,呈现明显的剂量反应关系。（３）ＤＶＣ内注射ＴＲＨ兴奋ＦＳＰＳＯ的效应可被静脉注射阿托品（０．２ｍｇ／ｋｇ）或迷走神经切断完全阻断,但不能被静脉注射酚妥拉明（１．５ｍｇ／ｋｇ）、心得安（１．５ｍｇ／ｋｇ）或脊髓切断术所阻断。结论：ＤＶＣ内ＴＲＨ可能对ＳＯ肌电有重要的调节作用,这种作用是通过迷走神经及外周Ｍ受体介导。     

地中海拟无枝酸杆菌甲基丙二酰CoA转羧基酶的纯化及酶学特性

经硫酸铵沉淀,ＤＥＡＥ－纤维素吸附,磷酸纤维素吸附和Ｓｅｐｈａｒｏｓｅ４Ｂ分子筛层析四步从地中海拟无枝酸杆菌纯化得到电泳纯ＭＣＴ酶,酶比活力为３．２１Ｕ／ｍｇ,纯化倍数１７８,酶活回收１４．９％。酶反应的最适ｐＨ和温度分别为７．０和３５℃。纯化ＭＣＴ酶对底物丙酰ＣｏＡ和草酰乙酸的米氏常数分别为０．０２７ｍｍｏｌ／Ｌ０．０３５０９ｍｍｏｌ／Ｌ．经ＳｅｐｈａｄｅｘＧ－１５０测定酶分子量为２０００００,ＳＤＳ－取丙烯酰胺电泳凝胶显示一条分子量６８０００的亚基蛋白带,说明该酶由三个等大小亚基组成．薄层等电聚焦测定酶等电点为ｐＩ６．０．二价金属离子Ｃｏ￣（２＋）和Ｆｅ￣（３＋）促进酶活力．采用原生质体裂解的方法发现ＭＣＴ酶是可能分布于胞浆和细胞膜上．     

Antioxidant effect of the marine algae Chlorella vulgaris against naphthalene-induced oxidative stress in the albino rats

Alcoholic extract of the marine algae Chlorella vulgaris was examined for its free radical scavenging effect with reference to naphthalene-induced lipid peroxidation in serum, liver, and kidney of rats. Initially, upon naphthalene intoxication (435 mg/kg body weight, intraperitoneally), the lipid peroxidation activity increased significantly (P < 0.001), and in contrast, the enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase) and non-enzymic antioxidants (glutathione, ascorbic acid, and α-tocopherol) levels decreased remarkably. When the naphthalene stressed rats were treated with Chlorella vulgaris extract (70 mg/kg body weight, orally), the lipid peroxidation activity reduced significantly (P < 0.001) and the activities of both the enzymic and non-enzymic antioxidants increased reaching near control values. The minimum concentration (70 mg/l) of the extract that exhibited maximum (85%) free radical scavenging activity was chosen for the experimental study. The present results suggest that Chlorella vulgaris extract exerts its chemo-preventive effect by modulating the antioxidants status and lipid peroxidation during naphthalene intoxication.     

枇杷花茶水提物的镇咳、抗炎与抗氧化作用研究

采用小鼠氨水致咳法研究枇杷花茶水提物镇咳效果,以二甲苯致小鼠耳肿胀法研究其抗炎效果,并从枇杷花茶的还原能力及对超氧阴离子和羟自由基的清除作用分析枇杷花茶水提物的抗氧化效果。结果表明,枇杷花茶的水提物高剂量组(3000 mg·kg-1)、低剂量组(700 mg·kg-1)均有镇咳抗炎效果,水提物的浓度越高,效果越好。各浓度枇杷花茶水提物均表现出一定的还原能力,对于羟基自由基和超氧阴离子都有一定的清除效果。其中,20 mg·mL-1水提物还原效果最好(吸光值0.903),超过0.2 mg·mL-1抗坏血酸(吸光值0.814);10 mg·mL-1的水提物对超氧阴离子的清除率为47.32%;20 mg·mL-1水提物对于羟基自由基的清除效果非常明显,清除率为91.62%。枇杷花茶水提物镇咳、抗炎、抗氧化效果明显。     

The Relationship Between Temperature Stress Resistance and Changes of the Endogenous Scavengers of Activated Oxygen in Hybrid Rice

The seedlings of hybrid rice were exposed to low(l℃) and high (40℃) temperatures and the permeability of plasma membrane, the activities of SOD, catalase, and peroxidase were assayed and the contents of malondialdehyde (MDA), ascorbic acid and glutathione were estimated. The ability of the seedlings to scavenge activated oxygen progresively decreased with the time of exposure to low temperature, concurrently MDA gradually accumulated and the permeability of the plasma membrane decreased. The amounts of MDA increased were different in the two hybrid combinations and were not in accordance with the ability of cold resistance. Comparing the more resistant variety “Wei-you 287” with the less resistant variety “Wei-you 49”, it was found that the leakage of electrolytes, the activities of SOD, peroxidase and catalase and the content of glutathione were all higher in the more resistant variety, but the accumulation of MDA was more in the less resistant variety. Higher temperature was less harmful than lower one to the seedlings of hybrid rice. Both enzymic and non-enzymic systems scavenging activated oxygen were similarly important in protecting the seedlings from damage by such oxygen.     

Exogenous spermidine differentially alters activities of some scavenging system enzymes, H(2)O(2) and superoxide radical levels in water-stressed cucumber leaves

In order to examine whether polyamines (PAs) modify the functioning of the scavenging system and oxidative stress levels in water-stressed plants, cucumber (Cucumis sativus L.) seedlings were treated with spermidine (Spd) prior to dehydration, and stress-evoked changes in superoxide dismutase (SOD) (EC 1.15.1.1), catalase (EC 1.11.1.6), guaiacol peroxidase (EC 1.11.1.7) activities, H(2)O(2) and superoxide radical levels were determined. Free PA content during Spd treatment and during the stress period were also determined. Exogenous application of Spd differentially influenced enzymes of the antioxidative system under stress conditions; we observed an increase of guaiacol peroxidase activity, and, to a lesser degree, a reduction of SOD and catalase activities in Spd-treated plants in comparison to untreated stressed plants. Hydrogen peroxide and superoxide radical contents were also reduced in stressed plants after Spd pretreatment. These positive effects were observed in the case of 1mM Spd concentration. A higher concentration (3mM) influenced negative, more significant stress-induced changes, but a lower concentration (0.1mM) had a very limited effect. In summary, PAs are able to moderate the activities of scavenging system enzymes and to influence oxidative stress intensity.     

咖啡和绿茶的抗氧化活性研究

茶和咖啡是全世界消费最多的饮料。该工作利用电子自旋共振(ESR)技术和ABTS〔2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid)〕等方法,研究和比较了3种绿茶(龙井、碧螺春和毛峰)和3种咖啡的抗氧化活性,以及对ABTS 、DPPH、超氧阴离子、羟基自由基、单线态氧的清除作用和对脂质过氧化的抑制作用。利用高压液相色谱(HPLC)分析了绿茶中的抗氧化成分之一EGCG((-)-epigallocatechin gallate)和咖啡中的抗氧化成分之一绿原酸(chlorogenic acid5,CQA)的含量。结果发现,如果按每克剂量比较,对于清除ABTS 的能力而言,茶和咖啡水提取液对ABTS 清除能力各有千秋,咖啡水提取液的比龙井、毛峰水提取液的高,但与碧螺春无显著差异,咖啡B比咖啡A和C强;按每杯茶(3g/200mL)和咖啡(2.4g/200mL)对ABTS 的清除能力进行比较,咖啡的比龙井和毛峰的高但比碧螺春低,咖啡B比咖啡A和C强。对超氧阴离子、羟基和DPPH自由基及单线态氧的清除作用和对脂质过氧化的抑制作用的研究表明,如果按每克剂量比较,茶和咖啡水提取液没有明显区别;按每杯量进行比较时,茶水提取液比咖啡水提取液对自由基的清除能力稍强。HPLC结果表明,EGCG含量在毛峰中最高,5CQA含量在咖啡B中最高。该研究结果表明茶和咖啡中均含有丰富的抗氧化成分,并都具有较强的抗氧化活性和清除自由基能力。     

Ultrasound-assisted extraction of some branded tea: Optimization based on polyphenol content,antioxidant potential and thermodynamic study

Tea is one of the top beverages used around the world every day, which contains a high amount of polyphenols and antioxidants. The main aim of this research is to quantify some marketed black tea (Rabea, Lipton, Alkbous, Green gold and Haritham) for phenolic contents and antioxidant potential evaluation by ultrasound solvent extraction and was compared with conventional extraction. Ultrasonic extraction was optimized by considering frequencies (26 kHz, 40 kHz), temperature (30, 40 and 50 °C), and power (30, 40 and 50%) at a fixed time of 30 min. In both the ultrasonic frequencies, 40 °C temperature and 40% power combination exhibited highest cumulative yield (mg/100 g DW), total phenolic content (mg gallic acid/g DW), flavonoids (mg/g DW) and DPPH radical scavenging activity (%) in all branded tea. Within each brand of tea, at any temperature-power combination at particular frequency results were not significantly different. But, at a similar condition of temperature power results were found significantly different between two frequencies. Furthermore, ultrasonic extraction process was analyzed thermodynamically by selecting some basic parameters. Thermodynamics results showed the extraction process was feasible, spontaneous and irreversible. Also, 26 kHz ultrasonic probe is more appropriate for the extraction purpose and thermodynamically more acceptable as compared to 40 kHz ultrasonic bath. Moreover, Haritham was selected as the best tea brand due to its high polyphenol contents and antioxidant potential.     

夏秋季遮光对山东黄金芽茶树生理生化特性的影响

选用遮光率分别为55%、70%、85%的黑色、蓝色遮阳网,观测遮光后茶园小气候、茶树叶色、叶绿素荧光参数、茶树生长状况及茶叶生化成分,分析不同遮光处理对山东黄金芽生理生化特性的影响,明确适宜夏秋季的遮光方式.结果表明: 与对照相比,遮光直接降低光照强度,茶园空气温度、叶面温度明显降低,空气湿度则增高;遮光程度越大,黄金芽叶色返绿越明显,叶绿素含量增幅越大;55%遮光处理能保持品种叶色黄化特性,且生化品质较好;而70%遮光率处理茶苗生长势较好,不受光胁迫;与蓝色遮阳网相比,黑色遮光处理能更好地促进茶树生长,保持叶色黄化和提高茶叶品质.黄金芽茶树品种苗期管理宜选择黑色70%遮光率处理(日光合有效辐射为1.2～3.5万lx),以促进茶树生长;成龄后则以黑色55%遮光处理(日光合有效辐射为1.8～5.5万lx)为优,既能保证黄金芽叶色黄化又能提高茶叶生化品质,从而充分发挥其品种特色,实现优质高产目标.     

Antioxidant activity and cytotoxicity of methanol extracts from aerial parts of Korean salad plants

The aim of this investigation was to determine the content of total phenolics, antioxidant activity and cytotoxicity of methanol extracts from the aerial parts of 11 Korean medicinal salad plants. The highest total phenolic content of the methanol extracts was found in Aster scaber (17.1 mg 100 g(-1)), followed by Ixeris dentate (16.4 mg 100 g(-1)), Aster yomena (12.0 mg 100 g(-1)) and Sedum sarmentosum (9.1 mg 100 g(-1)) of FW. Methanol extracts of Ixeris dentate and Aster scaber at 50 microg mL(-1) exhibited the highest DPPH radical scavenging activity by 86.4 and 83.3%, respectively. It was registered a dose-dependent increase of DPPH free radical scavenging activity. Total phenolic content of the studied plant extracts was correlated with the DPPH radical scavenging activity. It was found by means of MTT assay, that cytotoxicity of the methanol extracts was the highest against HCT-116. Methanol extracts from Petasites japonicus (IC(50)<25.0 microg mL(-1)) showed the highest activity against HCT-116, following by Angelica gigas (34.75 microg mL(-1)), Erythronium japonicum (44.06 microg mL(-1)), and Aster scaber (54.87 microg mL(-1)). In conclusion, the studied salad plants have high total phenolics content and high antioxidant activity. These plants dose-dependently increased DPPH free radical scavenging activity. The total phenolics level was highly correlated with the free radical scavenging activity. Most of the studied salad plants have potent cytotoxicity activity. The results of this investigation suggest that the extracts of studied salad plants could be an addition to basic medicine for some diseases.     

Antioxidant and Neuroprotective Properties of Sour Tea (Hibiscus sabdariffa, calyx) and Green Tea (Camellia sinensis) on some Pro-oxidant-induced Lipid Peroxidation in Brain in vitro

Oxidative stress is the cause of neurodegenerative disorders such as Lou Gehrig’s disease, Parkinson’s disease, and Huntington’s disease; one practical way to prevent and manage neurodegenerative diseases is through the eating of food rich in antioxidants (dietary means). This present study sought to compare the ability of aqueous extract of sour tea (Hibiscus sabdariffa, calyx) and green tea (Camellia sinensis) to prevent some pro-oxidant [Fe (II), sodium nitroprusside, quinolinic acid]-induced lipid peroxidation in rat’s brain in vitro. Aqueous extracts of both teas were prepared (1 g tea in 100 ml of hot water). Thereafter, the ability of the extracts to prevent 25 μM FeSO₄, 7 μM sodium nitroprusside, and 1 mM quinolinic acid-induced lipid peroxidation in isolated rat’s brain tissue preparation was determined in vitro. Subsequently, the total phenol content, reducing power, Fe (II) chelating and OH radical scavenging ability were determined. The results of the study revealed that both teas significantly (P < 0.05) inhibit lipid peroxidation in basal and pro-oxidant-induced lipid peroxidation in the rat’s brain homogenates in a dose-dependent manner. Also, the teas had high total phenol content [sour (13.3 mg/g); green (24.5 mg/g)], reducing power, and Fe (II) chelating and OH radical scavenging ability (except sour tea). However, green tea had a significantly higher (P < 0.05) ability to inhibit lipid peroxidation in both the basal and pro-oxidant-induced lipid peroxidation in rat’s brain homogenates in vitro. Therefore, it is obvious from the study that both teas had high antioxidant properties and could inhibit Fe²⁺, sodium nitroprusside, and quinolinic acid-induced lipid peroxidation in brain. However, green tea had a higher inhibitory effect, which may probably be due to its high total phenol content, reducing power, Fe (II) chelating ability, and OH radical scavenging ability.     

基于植物rbcL基因测序对茶叶进行掺杂检验

茶叶是世界上最受人们欢迎的饮品之一,但茶叶中掺杂其他植物成分的现象时有发生。依靠传统的感官和理化检验方法难以准确判断茶叶中掺杂的植物种类。报道一种基于植物核酮糖-1,5-二磷酸羧化酶/加氧酶大亚基(rbc L)基因序列进行茶叶掺杂定性检测的方法,包括rbc L基因片段的扩增、测序和序列分析等步骤。利用所建立的方法对7份茶叶样品进行分析,发现岳阳黄茶(黄茶)和信阳毛尖(绿茶)未掺杂其他植物成分,而正山小种(红茶)、铁观音(乌龙茶)、太姥银针(白茶)、六堡茶和普洱茶(黑茶)均一定程度上混杂有其他植物成分。所建立的检测方法对样品的需求量小,操作简便,检测结果可靠性高,能定性检测各类茶叶中是否掺杂及掺杂了何种植物成分。