夹竹桃对钉螺的毒杀作用及机理研究

血吸虫病（Schistosomiasis）是严重危害人民身体健康的疾病…。疫区的淡水资源既不能作为饮用、洗涤等生活安全用水,也不能作为农田灌溉、水产养殖等生产安全用水,不但极大地制约了国家经济的发展,同时还限制了人们生活、生产活动的自由,严重威胁着人们的身体健康和生命。此外,大规模使用氯硝柳胺等化学灭螺剂所导致的化学污染比血吸虫、生活垃圾以及工业三废等造成的污染面积更大、     

夹竹桃灭钉螺效果初报

1　引　　言在防治血吸虫病的过程中 ,人们一直致力于消灭其唯一中间宿主钉螺 .近年来长江中下游生态环境破坏严重 ,一些地方有螺面积扩大 ,疫情回升 .常用化学药物灭螺法虽有较明显的灭螺效果 ,但也造成了严重的环境污染 .90年代以来生物灭螺开始成为比较活跃的研究领域 ,在筛选灭螺植物 ,提取植物灭螺活性成分和利用植物他感作用灭螺等方面已取得了许多成绩[1～ 4 ,7,8] .目前 ,植物灭螺难以推广的主要问题在于利用新鲜植物材料灭螺常需要较高的浓度 ,而原料来源往往有限 ;提取植物灭螺活性成分制作灭螺剂的成本较高 ,难以广泛应用 .因此 …     

夹竹桃科植物中强心苷的分布及其药理活性研究进展

本文概述了夹竹桃科植物中强心苷的分布及国内外从夹竹桃科植物中分离得到的强心苷类化合物药理活性研究进展。     

益母草（Leonurus artemisia）灭螺效果研究

本实验研充分别采用益母草的根、茎、叶的0．10、0．25、0．50、2．00、1．00g／L和水苏碱的0．20、0．40、0．60、0．80、1．00g/L 5个不同浓度梯度的处理液处理钉螺,设清水和0．001g／L浓度的氯硝柳胺溶液为对照。结果表明：（1）益母草各部分的水浸液均有很好的灭螺效果。用不同浓度的处理液浸杀钉螺,在不同时间的处理下,钉螺死亡率存在差异,其钉螺死亡率是随处理浓度的增加和时间的延长呈上升趋势,0．5g／L以上的益母草根、茎、叶、化水浸液和浓度达0．60g／L以上的水苏碱处理液均可达到100％的明显毒杀钉螺致死效果,与通常使用浓度0．0001g／L氯硝柳胺溶液的灭螺效果相当,不过益母苹根、茎、叶水浸液的毒效较氯硝柳胺略慢,用0．0001g／L氯硝柳胺溶液处理钉螺2—3d可达100％的死亡率,而用0．5g／L以上的益母草根、茎、叶水浸液水溶液处理需要3—5d才能达到同样的效果;灭螺效果顺序依次为：叶〉茎〉根。（2）钉螺趋避性研究表明水苏碱和益母草根、茎和叶的处理液对钉螺具有明显的驱逐作用,而盐酸益母草碱几乎没有作用。由此获得化感作用植物益母草灭螺的化学生态学证据。为研制新的具中国特色的植物成份灭螺剂打下了基础。并为合成仿生灭螺剂以及最终构建生态工程中强化感作用植物群落灭螺提供理论依据。     

益母草(Leonurus artemisia) 灭螺效果研究

本实验研究分别采用益母草的根、茎、叶的0.10、0.25、0.50、2.00、1.00g/L和水苏碱的0.20、0.40、0.60、0.80、1.00g/L5个不同浓度梯度的处理液处理钉螺,设清水和0.001g/L浓度的氯硝柳胺溶液为对照。结果表明:(1)益母草各部分的水浸液均有很好的灭螺效果,用不同浓度的处理液浸杀钉螺,在不同时间的处理下,钉螺死亡率存在差异,其钉螺死亡率是随处理浓度的增加和时间的延长呈上升趋势,0.5g/L以上的益母草根、茎、叶、化水浸液和浓度达0.60g/L以上的水苏碱处理液均可达到100%的明显毒杀钉螺致死效果,与通常使用浓度0.0001g/L氯硝柳胺溶液的灭螺效果相当,不过益母草根、茎、叶水浸液的毒效较氯硝柳胺略慢,用0.0001g/L氯硝柳胺溶液处理钉螺2~3d可达100%的死亡率,而用0.5g/L以上的益母草根、茎、叶水浸液水溶液处理需要3~5d才能达到同样的效果;灭螺效果顺序依次为:叶>茎>根。(2)钉螺趋避性研究表明水苏碱和益母草根、茎和叶的处理液对钉螺具有明显的驱逐作用,而盐酸益母草碱几乎没有作用。由此获得化感作用植物益母草灭螺的化学生态学证据,为研制新的具中国特色的植物成份灭螺剂打下了基础,并为合成仿生灭螺剂以及最终构建生态工程中强化感作用植物群落灭螺提供理论依据。     

利用植物他感作用灭螺效果的研究

通过调查有螺滩地林下植被的演变和乌柏（Ｓａｐｉｕｍｓｅｂｉｐｅｒｕｍ）、枫杨（Ｐｔｅｒｏｃａｒｙａｓｔｅｎｏｐｔｅｒａ）等滩地造林树种的灭螺效果发现,鸡矢藤（Ｐａｅｄｅｒｉａｓｃａｎｄｅｎｓ）、水芹（Ｏｅｎａｎｔｈｅｊａｖａｎｉｃａ）的个体数量与钉螺的数量呈正相关关系,Ｘ２分别为１２．８和１１．２（ａ＜０．０２）,而益母草（Ｌｅｏｎｕｒｕｓａｒｔｅｍｉｓｉａ）、问荆（Ｅｑｕｉｓｅｔｕｍａｒｖｅｎｓｅ）、酸模叶蓼（Ｒｕｍｅｘａｃｅｔｏｓａ）、打碗花（Ｃａｌｙｓｔｅｇｉａｈｅｄｅｒａｃｅａ）、紫云英（Ａｓｔｒａｇａｌｕｓｓｉｎｉｃｕｓ）等与钉螺的数量呈负相关关系（ａ＜０．０２）经过一个汛期,枫杨、乌柏叶片使钉螺死亡率从草滩对照的２％升至４３．３％和４４．１％     

樟树水浸液的灭螺效果

研究了新鲜樟树的茎皮、根皮和叶的水浸液对钉螺的杀灭效果。结果表明：通过一定时间的处理,樟树水浸液对钉螺有明显的毒杀作用。其中,0．5％以上的茎皮和根皮的水浸液对钉螺具有35％-100％的毒杀作用;处理时间在72h时,死螺率可达80％-100％。0．5％的樟树根皮水浸液浸泡72h时,死螺率为95％;1％的樟树根皮水浸液浸泡72h时,死螺率为100％。当用同种水浸液浸泡时,钉螺死亡率随水浸液浓度的增加而升高;随着浸泡时间的延长,钉螺的死亡率也升高。     

枫杨水浸液灭螺实验研究

采用枫杨的新鲜根皮、茎皮和叶的水浸液处理螺,并用五氯酚钠溶液处理和清水饲养钉螺实验作对照,结果表明,５％以上的枫杨各部水浸液对钉螺个有２０－１００％的毒杀致死作用,处理时间在２４０ｈ左右时,其经可达９３．５－１００％,含２．５％的新鲜枫杨叶和２．５％的新鲜乌桕叶、池杉叶、樟叶、羊蹄全株、青蒿全株等的混浸液,处理钉螺２４０ｈ亦分别具有９６．７％、９３．３％、８０％、１００％、８６．７％的灭螺效果。     

夹竹桃对钉螺酯酶同工酶作用的初步分析

夹竹桃 (Nerium indicum)为夹竹桃科 (Apocynaceae)常绿大灌木 ,被广泛栽培用于观赏、绿化〔1〕。因其资源广泛 ,取材方便 ,叶含强心苷、欧夹竹桃苷等有效成分 ,可杀虫 〔2 ,3〕,故被我们用作杀钉螺 (Oncomelania hupensis)试验材料。从试验结果发现其有较强的杀螺作用 ,但其杀螺的机理尚不明。因此 ,为探讨其杀螺的生理生化机制 ,笔者从钉螺对外界环境反应强烈 〔4〕且具有解毒作用的酯酶 〔5,6〕着手 ,报道夹竹桃对钉螺酯酶同工酶的作用。1 　材料和方法1 .1　材料夹竹桃于 1 998年 4月采自湖北大学校内 ,取其当年萌生枝上部叶 ,洗净 ,…     

钉螺对夹竹桃化感物质三萜总皂甙毒理作用的反应

本文分别用0.02 mg/L-0.1mg/L系列浓度的夹竹桃三萜总皂甙水溶液处理钉螺 ,设无氯清水饲养与浓度为1 mg/L 氯硝柳胺溶液浸杀对照,研究夹竹桃三萜总皂甙是否为夹竹桃灭螺的化感物质及其作用机理.结果表明:用不同浓度梯度的夹竹桃三萜总皂甙水溶液处理钉螺均有一定的杀灭作用, 对试验数据进行概率单位回归分析,表明浸杀处理2、3、 4和5 d的LC50分别为78.31、30.26、20.50、14.19 mg/L,其对应的95%置信区间分别为 63.60-108.19、9.49-44.42、2.86-30.90、0.23-22.79 mg/L;以不同处理浓度、时间下钉螺的死亡率为因变量,对夹竹桃三萜总皂甙水溶液浸杀灭螺效果进行方差分析,结果显示夹竹桃三萜总皂甙的浓度、处理时间的长短对钉螺的死亡率均有极显著的作用效果,并且药液浓度与处理时间之间的交互效应也极显著.扫描电镜观察结果显示40 mg/L浓度处理后钉螺软体表层呈现明显的损伤;透射电镜观察40 mg/L浓度处理后钉螺样品发现24 h后肝细胞核肿胀,核仁消失,核质稀疏,内质网断裂,线粒体增多;当处理时间延长到48 h时,损伤加重,内质网几乎全部囊泡化,细胞核开始破裂,线粒体也破裂;处理24 h后钉螺小肠表面的微绒毛排列有些不整齐,有一小部分微绒毛出现脱落,肠周缘细胞出现肿胀,细胞核出现少量小空泡;处理48 h时的钉螺小肠表面微绒毛排列明显不整齐,大部分微绒毛脱落,肠周缘细胞肿胀明显,有大量空泡,有时还出现游离核,胞质内的细胞器有大小不等的空泡样变性 ,细胞器结构已无法辨别,严重变性,胞膜不完整.采用聚丙稀酰胺电泳技术分离经40 mg/ L夹竹桃三萜总皂甙水溶液处理1、2、3、4、5 d后的钉螺样品的酯酶同工酶,处理1-2 d后酶的活性比清水对照增强,应激反应明显,而处理达3 d时酶的活性开始下降,5 d时,酶谱带数及其色泽与用1 mg/L氯硝柳胺水溶液处理1 d的对照相当.本研究获得化感作用植物夹竹桃灭螺的超微结构证据[动物学报 54(3):489-499,2008].     

夹竹桃灭钉螺效果初报

A laboratory experiment at 20±5℃ shows that the water extract of fresh Nerium indicum had an obvious effect on killing Oncomelania hupensis. Treated with 0.1% water extract for four days, the mortality of O. hupensis was up to 100%. The effect of different tissues of N. indicum on O. hupensis was in order of stem phloem>leaf>root phloem>flower. The effect of N. indicum on O. hupensis was about ten times higher than that of Pterocarya stenoptera and Rumex japonicus, and was equal to that of 1×10^-3mg·L^-1 niclosamidum.     

Isoform-specific stimulation of cardiac Na/K pumps by nanomolar concentrations of glycosides

It is well-known that micromolar to millimolar concentrations of cardiac glycosides inhibit Na/K pump activity, however, some early reports suggested nanomolar concentrations of these glycosides stimulate activity. These early reports were based on indirect measurements in multicellular preparations, hence, there was some uncertainty whether ion accumulation/depletion rather than pump stimulation caused the observations. Here, we utilize the whole-cell patch-clamp technique on isolated cardiac myocytes to directly measure Na/K pump current (I(P)) in conditions that minimize the possibility of ion accumulation/depletion causing the observed effects. In guinea pig ventricular myocytes, nanomolar concentrations of dihydro-ouabain (DHO) caused an outward current that appeared to be due to stimulation of I(P) because of the following: (1) it was absent in 0 mM [K(+)](o), as was I(P); (2) it was absent in 0 mM [Na(+)](i), as was I(P); (3) at reduced [Na(+)](i), the outward current was reduced in proportion to the reduction in I(P); (4) it was eliminated by intracellular vanadate, as was I(P). Our previous work suggested guinea pig ventricular myocytes coexpress the alpha(1)- and alpha(2)-isoforms of the Na/K pumps. The stimulation of I(P) appears to be through stimulation of the high glycoside affinity alpha(2)-isoform and not the alpha(1)-isoform because of the following: (1) regulatory signals that specifically increased activity of the alpha(2)-isoform increased the amplitude of the stimulation; (2) regulatory signals that specifically altered the activity of the alpha(1)-isoform did not affect the stimulation; (3) changes in [K(+)](o) that affected activity of the alpha(1)-isoform, but not the alpha(2)-isoform, did not affect the stimulation; (4) myocytes from one group of guinea pigs expressed the alpha(1)-isoform but not the alpha(2)-isoform, and these myocytes did not show the stimulation. At 10 nM DHO, total I(P) increased by 35 +/- 10% (mean +/- SD, n = 18). If one accepts the hypothesis that this increase is due to stimulation of just the alpha(2)-isoform, then activity of the alpha(2)-isoform increased by 107 +/- 30%. In the guinea pig myocytes, nanomolar ouabain as well as DHO stimulated the alpha(2)-isoform, but both the stimulatory and inhibitory concentrations of ouabain were approximately 10-fold lower than those for DHO. Stimulation of I(P) by nanomolar DHO was observed in canine atrial and ventricular myocytes, which express the alpha(1)- and alpha(3)-isoforms of the Na/K pumps, suggesting the other high glycoside affinity isoform (the alpha(3)-isoform) also was stimulated by nanomolar concentrations of DHO. Human atrial and ventricular myocytes express all three isoforms, but isoform affinity for glycosides is too similar to separate their activity. Nevertheless, nanomolar DHO caused a stimulation of I(P) that was very similar to that seen in other species. Thus, in all species studied, nanomolar DHO caused stimulation of I(P), and where the contributions of the high glycoside affinity alpha(2)- and alpha(3)-isoforms could be separated from that of the alpha(1)-isoform, it was only the high glycoside affinity isoform that was stimulated. These observations support early reports that nanomolar concentrations of glycosides stimulate Na/K pump activity, and suggest a novel mechanism of isoform-specific regulation of I(P) in heart by nanomolar concentrations of endogenous ouabain-like molecules.     

Intracellular distribution of cardiac glycosides in leaves of Convallaria majalis

In order to investigate the intracellular distribution of the cardiac glycosides in leaves of Convallaria majalis, cell organelles were prepared by several methods. After mechanical disruption of the cells and differential centrifugation, the cardenolide content obtained was determined using the Baljet reaction. Most of the cardiac glycoside fraction was found in the soluble supernatant. However, a low but significant amount was also found in the 10 000g particles. Protoplasts and vacuoles were prepared by enzymic digestion of leaves. The cardenolide to protein ratio of vacuoles was far higher than that of protoplasts or the cytoplasmic fraction. The cardenolide content of isolated vacuoles relative to their number agreed well with the corresponding value obtained for protoplasts. This demonstrates clearly that cardiac glycosides are stored predominantly in the vacuoles of Convallaria majalis.     

基于LAI的东亚飞蝗发生面积的预测模型

20世纪80年代以来东亚飞蝗在我国再度猖獗危害,及时、准确地监测东亚飞蝗的危害状况,对于东亚飞蝗的有效防治有重要意义.以河北省黄骅市为研究区,从光学模型的建立机理为着眼点,定量分析和对比了4种由植被冠层孔隙度反演LAI的算法.结果表明,LAI与植被指数之间呈明显的正相关关系,即随着LAI的增大,植被指数也在增大;在4种估算方法中,LAI-2000算法最适用于研究区植被LAI的估算.此外,还分析了LAI与飞蝗发生面积的关系,发现两者呈负相关.并在此基础上建立了飞蝗发生面积的预测模型,即：ALO=-aln（LAI）＋b,其中,a、b为调节系数.     

Cardiac glycosides of the root bark of Nerium odorum

In addition to the known odorosides, the β-d-digitaloside and β-d-glucosyl-(1 → 4)-β-d-digitaloside of uzarigenin were isolated from the root bark of Nerium odorum. Odoroside B was obtained in remarkably high yield among the digitoxigenin and uzarigenin glycosides. With the aid of polyamide column chromatography, oleandrigenin β-gentiobiosyl-(1 → 4)-β-d-digitaloside ( = 16-O-acetylneogitostin) was isolated along with other oleandrigenin glycosides.     

Spirostanol glycosides from Asparagus plumosus

Three spirostanol glycosides were isolated from a methanol extract of the leaves of Asparagus plumosus and characterized.