青藏高原“黑土滩”常见毒草对甘肃马先蒿的化感作用

以青藏高原"黑土滩"典型毒草黄花棘豆(Oxytropis ochrocephala)、瑞香狼毒(Stellera chamaejasme)、黄帚橐吾(Ligularia virgaurea)、密花香薷(Elsholtzia densa)和南山蒿(Artemisia nanschanica)为供体材料,在实验室条件下测试了它们的根、茎、叶水浸提液对甘肃马先蒿(Pedicularis kansuensis)的化感作用,以期寻找对甘肃马先蒿种子萌发和幼苗生长具有生态化感抑制作用的植物种类及部位。结果表明,随着5种毒草各器官水浸提液浓度的升高,其对甘肃马先蒿化感作用增强;且同一植物在测试浓度相同的条件下,表现为叶、根的水浸提液对甘肃马先蒿种子和幼苗的抑制作用强于茎的浸提液。从5种毒草化感作用的综合表现看,黄花棘豆的叶和根、南山蒿的叶在浸提液浓度为25 g/L时对甘肃马先蒿幼苗生长的抑制作用显著大于其他毒草;当作用浓度升至100 g/L时,对甘肃马先蒿种子萌发和幼苗生长都表现出致死作用。因此,对黄花棘豆叶、根和南山蒿叶等植物器官的化感作用应作进一步的研究,将有望开发出针对甘肃马先蒿的专用生物源控制剂。     

高寒地区白苞筋骨草对几种禾草的化感作用

采用青藏高原“黑土滩”次生毒杂草群落的优势植物——白苞筋骨草（Aerba lupulin）地上部分和地下部分水浸液,对青藏高原高寒地区4种禾草种子萌发、幼苗生长的抑制作用进行了分析。结果表明：白苞筋骨草地上部分水浸液对4种禾草种子萌发和幼苗生长具有显著抑制作用（P<0.05）,地下部分水浸液的化感抑制作用不显著（P>0.05）;4种牧草种子萌发对白苞筋骨草水浸提物敏感性强弱顺序为：垂穗披碱草（Elymus nutans）＞老芒麦（E. sibiricus）＞冷地早熟禾（Poa crymophila）＞中华羊茅 （Festuca sinensis）,禾草幼苗生长对白苞筋骨草水浸液的敏感性强弱顺序为：垂穗披碱草＞中华羊茅＞老芒麦＞冷地早熟禾;整体上,4种牧草对白苞筋骨草化感作用的敏感性强弱顺序为：垂穗披碱草＞老芒麦＞冷地早熟禾＞中华羊茅;4种牧草幼苗生长对白苞筋骨草的水浸液敏感性弱于种子萌发。白苞筋骨草的化感抑制作用是高寒地区毒杂草在退化草地蔓延,并最终形成"黑土滩"次生毒杂草群落的一个因素。     

12种有毒植物的化感效应比较研究

以油菜、燕麦、反枝苋和狗尾草为受体,采用室内生物测定法和盆栽法,研究了甘肃天祝天然草地12种有毒植物的化感作用.结果表明:离体条件下,黄花棘豆、臭蒿、节烈角茴香和露蕊乌头植株水浸液对4种受体植物化感作用较强,其综合化感效应值(M)分别为-0.781 5、-0.685 9、-0.667 0和-0.643 2;其次是密花香薷、醉马草、美丽凤毛菊、甘肃马先蒿、迷果芹和异叶青兰,其M值均低于-0.4;对受体植物化感作用较弱的是乳白香青(M值为-0.343 9)和铁棒锤(M值为-0.262 5).黄花棘豆植株对盆栽的油菜、燕麦、反枝苋和狗尾草幼苗生长有较强的抑制作用,综合化感效应M值分别为-0.529 6、-0.356 2、-0.520 1和-0.588 4.可见黄花棘豆表现出较强的化感作用,具有一定的开发利用价值.     

瑞香狼毒对青藏高原东部高寒草甸主要物种花粉萌发和种子结实的花粉化感效应

花粉化感是一类特殊的化感作用,能够抑制其它物种的花粉萌发和种子结实。研究了瑞香狼毒(Stellera chamaejasme)花粉水浸提液对其它物种花粉萌发和种子结实的潜在化感抑制作用,包括:在实验室中,用一系列浓度的狼毒花粉水浸提液对与它同花期的其它6个物种(秦艽(Gentiana macrophylla Pall.var.fetissowii),湿生扁蕾(Gentianopsis paludosa(Hook.f.)Ma var.paludosa),鳞叶龙胆(Gentiana squarrosa Ledeb.),椭圆叶花锚(Halenia elliptica D.Don var.elliptica),高原毛茛(Ranunculustanguticus(Maxim.)Ovcz.var.tanguticus)和鹅绒委陵菜(Potentilla anserina L.var.anserina))以及自身花粉进行测试,测定花粉萌发率;在野外,在其它4个物种(秦艽,湿生扁蕾,鳞叶龙胆和椭圆叶花锚)的柱头上施用上述浓度的狼毒花粉水浸提液,观察种子结实率。实验室的花粉萌发试验证明,狼毒花粉对自身花粉萌发没有自毒作用,而其它受试的所有物种的花粉萌发率随着狼毒花粉浸提液浓度的增加呈显著地非线性降低。大约3个狼毒花粉的浸提液就可以抑制受试的多数物种的50%的花粉萌发。在野外试验中,发现受试的4个物种种子结实率随狼毒花粉浸提液浓度的增加呈显著地非线性降低。狼毒可能通过花粉化感对其周围其它物种的有性繁殖存在抑制作用,但其它物种可能通过花期在季节或昼夜上的分异避免受到狼毒花粉化感作用的影响,或者通过无性繁殖来维持种群繁衍。     

本氏针茅根际土提取物对本氏针茅及其优势种种子萌发的影响

以本氏针茅及其优势种大针茅和百里香种子为受体,采用生物检测的方法研究了0(对照)、0.1、0.2和0.5g/mL本氏针茅根际土甲醇浸提液和水浸提液对3种受体种子萌发的影响,以探究草地演替过程中物种间的生态关系和化感作用的表现形式。结果显示:(1)甲醇浸提液对3种受体种子的发芽均有抑制作用;水浸提液对本氏针茅发芽有促进作用,对百里香有部分促进作用,而对大针茅有抑制作用。(2)甲醇浸提液对本氏针茅和大针茅胚根和胚芽生长无显著影响,而抑制百里香胚根和胚芽的生长;水浸提液对本氏针茅胚根生长无显著影响,对本氏针茅胚芽生长具有显著促进作用,而对其它两种受体胚根和胚芽均无显著影响。(3)各种浓度甲醇浸提液对大针茅和百里香生长表现出了化感综合抑制效应,对本氏针茅生长于0.2g/mL时表现出化感综合抑制效应,其它2种浓度(0.1、0.5g/mL)表现为化感综合促进效应;水浸提液对本氏针茅和百里香表现为化感综合促进效应,而对大针茅表现为化感综合抑制效应。研究表明,本氏针茅根际土甲醇浸提液和水浸提液的化感物质存在差异;不同受体对同一浸提液反应不同,同一受体对不同浸提液的反应也不同。     

黄瓜种子及其萌发期的化感作用研究

以大白菜、萝卜、番茄和黄瓜种子为受体,采用实验室培养皿种子发芽生物测试法研究了黄瓜种子浸提液、种子萌发、胚根和芽苗分泌物、芽苗腐解物和芽苗浸提液的化感效应。结果表明:(1)黄瓜种子浸提液对大白菜、萝卜、番茄和黄瓜种子萌发均有化感抑制作用,即黄瓜种子内含有某些化感抑制物质。(2)在水浸提过的黄瓜种子萌发过程中,它不仅对其近邻套种的大白菜、萝卜和番茄种子萌发产生化感抑制作用,而且其胚根和芽苗分泌物对后茬播种的4种蔬菜种子发芽也表现出不同程度的化感抑制作用;黄瓜芽苗腐解物和芽苗水浸提液也对各受体蔬菜种子发芽与生长产生不同程度的化感抑制作用,且随着腐解芽苗量的增加或浸提液浓度的升高,各受体蔬菜种子的发芽指标值、化感效应指数值和综合效应值随之降低。(3)黄瓜种子浸提液及芽苗各器官的化感物质对黄瓜种子的萌发与生长产生了自毒作用,且黄瓜芽苗腐解物、芽苗浸提液、胚根及芽苗分泌物对受体黄瓜的自毒作用均为最大。研究发现,黄瓜种子浸提液、种子萌发时期以及芽苗各器官的化感物质主要是通过抑制受体胚根的生长而起化感抑制作用,即受体蔬菜种子胚根对化感效应最为敏感;因黄瓜种子及萌发期释放化感物质的途径有所不同,导致受体大白菜、萝卜、黄瓜和番茄的化感响应也不相同;在黄瓜种子萌发和芽苗生长的早期,化感物质即开始在芽苗体内进行合成与积累,一部分可通过胚根和芽苗分泌途径释放到环境中,另一部分可通过芽苗腐解途径释放化感物质,并对受体蔬菜种子萌发与生长表现出较强的化感抑制作用。     

加拿大一枝黄花根系和根际土壤水浸液对萝卜和白菜种子萌发及幼苗生长的影响

用加拿大一枝黄花根系及根际土壤水浸液对白菜和萝卜的化感作用进行了研究。结果表明,加拿大一枝黄花根系水浸液和根际土壤水浸液对白菜和萝卜种子的萌发具有抑制作用。根际土壤水浸液对白策和萝卜幼苗生长具有促进作用,而对其胚根的伸长生长则具有显著的抑制作用。0．05g／mL根系水浸液处理显著抑制萝卜幼根的伸长,但其它浓度对白菜和萝卜幼苗生长和根系伸长的影响不明显。实验还表明高浓度的根系水浸液和根际土壤水浸液明显抑制白菜和萝卜的根系脱氢酶活性和硝酸还原酶活性。     

不同年龄瑞香狼毒的根水提液对青藏高原高寒草甸4 种常见植物的化感作用

瑞香狼毒是我国主要的草地毒害草, 也是青藏高原高寒草甸危害最为严重的草地毒害草之一。已有研究表明, 狼毒根系及其器官具有化感作用, 但是对不同年龄狼毒植株化感作用的差异尚未见报道。研究选取2 个年龄段(3-5 龄与8-10 龄)的狼毒植株, 对比研究了其根系水提液对4 种高寒草甸常见植物垂穗披碱草(Elymus nutans)、歪头菜(Vicia unijuga)、草玉梅(Anemone rivularis)、川西翠雀(Delphinium tongolense)种子和幼苗生理与生长的化感作用。结果显示: 狼毒根系水提液提高了4种植物种子内脯氨酸含量和质膜透性含量以及幼苗苗内丙二醛(MDA)和超氧化物歧化酶(SOD)含量, 降低了4 种植物萌发种子体内可溶性糖和可溶性蛋白含量, 并且有效的抑制4 种植物根系与幼苗的生长。同等浓度的根系水提液, 8-10 龄的狼毒对4种常见植物种子和幼苗的生长与生理的化感作用大于3-5 龄的狼毒所产生的化感作用, 其中8-10 龄狼毒稀释10 倍根系水提液对部分植物种子与幼苗的生理和生长的化感作用与3-5 龄狼毒根系水提原液所产生的化感作用相似。研究表明瑞香狼毒随年龄增加化感作用增强, 8-10 龄狼毒比3-5 龄狼毒在群落竞争中有更大的竞争优势, 其高龄狼毒较低浓度的根系水提液产生了与低龄狼毒较高浓度的水提液相似的化感效应。     

黄花棘豆水提液对燕麦的化感作用及其机理研究

以燕麦种子和幼苗为受体,采用室内培养皿法、室内盆栽法和生化分析法,研究了甘肃天祝草地有毒植物黄花棘豆水浸提液对燕麦种子、幼苗的化感作用及其作用机理.结果表明:(1)黄花棘豆水提液均可抑制燕麦种子萌发和幼苗生长,且化感抑制作用随着水提液浓度的增大显著增强;燕麦幼苗根在高浓度的黄花棘豆水提液作用下表现出畸形.(2)随着水提液浓度的增大,根尖有丝分裂逐渐减弱及分裂高峰时间逐渐推迟,种子淀粉酶活性也逐渐下降.(3)燕麦幼苗茎叶部和根部的可溶性糖、可溶性蛋白和叶绿素的含量随着水提液浓度的增大以及作用时间的延长逐渐降低,丙二醛含量则逐渐升高.(4)随着黄花棘豆水提液浓度的增大,其对燕麦幼苗过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性的抑制作用逐渐增强,随着作用时间的延长抑制作用逐渐减弱.研究发现,黄花棘豆水提液通过降低燕麦幼苗渗透调节物质含量,抑制保护性酶活性,增加膜脂过氧化伤害,导致根尖细胞分裂缓慢,抑制燕麦种子萌发和幼苗生长,从而表现出化感作用,且化感作用随着浓度的增加而增强.     

黄花蒿对4种受体植物的化感作用研究

采用室内生物测定法,以小麦、燕麦、黄瓜和萝卜为受体,研究了黄花蒿对受体植物的化感作用,结果显示:黄花蒿水浸提液对小麦、燕麦的化感综合效应(SE)为56.29、57.17;其地上部淋溶物对小麦和黄瓜表现为抑制作用,对燕麦和萝卜表现为促进作用;其茎叶挥发物对4种受体植物根长生长有较强的抑制作用;其残体分解物前10d对受体有很强的抑制作用,根系分泌物对小麦和燕麦抑制作用较强,对萝卜和黄瓜表现为促进作用。结果表明,黄花蒿5种不同途径来源的化感物质对4种受体植物都有不同程度的化感作用,且黄花蒿主要是通过地上部淋溶、挥发向环境中释放化感物质,其次是通过根系分泌物对授体植物产生化感作用。     

中药提取物对酵母菌抗真菌活性研究

目的探讨6味中药2种方法提取成分对酵母菌的抑菌和杀菌作用。方法采用药基琼脂稀释法,测定6味中药水提和醇提成分对白念珠菌和糠秕马拉色菌的MIC和MFC。结果对白念珠菌：水提黄连、醇提黄柏、醇提土槿皮MIC范围分别为0．625—1．25mg／mL、0．625～1．25mg/mL、0．313—0．625mg／mL;均值均为0．625mg／mL;对糠秕马拉色菌：水提和醇提黄连MIC范围分别为0．625～1．25mg／mL和1．25mg／mL,均值均为1．25mg／mL。对白念珠菌：醇提土槿皮MFC范围0．625～2．5mg/mL,均值0．625rag／mL。结论水提黄连、醇提黄柏和土槿皮对白念珠菌有较强抑菌作用,其中醇提土槿皮有较强杀菌作用。水提和醇提黄连对糠秕马拉色菌有较强抑菌作用。     

生姜水浸液对生姜幼苗根际土壤酶活性、微生物群落结构及土壤养分的影响

本文以生姜为材料,研究生姜不同部位（根茎、茎和叶）、不同浓度（10、20、40和80 g L-1）的水浸液对生姜幼苗根际土的微生物数量、土壤酶活性及土壤养分含量的影响,并通过HPLC定量分析了生姜各部位水浸液中所含酚酸类（香草酸、丁香酸、对羟基苯甲酸、香豆酸和阿魏酸）、香豆素类（伞花内脂和7-甲氧基香豆素）化合物的含量。结果表明：三种生姜水浸液对所测六种土壤酶活性均产生了不同程度的影响,其中影响最大的是酸性磷酸酶和蔗糖酶,在10 g L-1 时就达到了显著性差异水平,并且所有酶均有随着水浸液浓度的增加而呈增大的趋势;相同部位的水浸液随着浓度的增加,细菌和真菌的数量呈增加趋势,而放线菌的数量呈减少趋势;三种生姜水浸液均随着浓度的增加降低了土壤中有机质的含量,加剧了土壤中硝态氮含量的积累,根茎水浸液对土壤有效磷、速效钾和铵态氮均显示出低浓度提高其含量而高浓度降低其含量的趋势,而茎和叶水浸液则随着浓度的增加均降低了其含量。生姜水浸液中主要化感成分包括：根茎水浸液主要是丁香酸和伞花内脂;茎水浸液主要是阿魏酸,且其含量最高为73.4 ug/g;叶水浸液除了阿魏酸,其他六种物质均被检测出,但含量较高的主要有丁香酸、伞花内脂和香豆酸。     

Biological screening of traditional preparations from some medicinal plants used as antidiarrhoeal in Kinshasa, Congo.

Forty six aqueous extracts from 38 medicinal plant species belonging to different families were selected on the basis of their traditional medicinal use as antidiarrhoeic agents. They were submitted in a broad biological screening including antibacterial, antiamoebic and antispasmodic activities. The results of the testing have indicated that 37 extracts (80.43%), 33 (71.74%) and 32 (69.54%) exhibited some level of antibacterial, antiamoebic and antispasmodic activity respectively. Only 8 plant extracts (17.39%) would act as antidiarrhoeic agents by a triple pronounced antibacterial, antiamoebic and antispasmodic action. They include aqueous extracts from Euphorbia hirta whole plant, leaves of Psidium guajava and Tithonia diversifolia, root bark of Alchornea cordifolia, Heinsia pulchella, Paropsia brazzeana, Rauwolfia obscura and Voacanga africana.     

Allelopathic Potential and Mechanism of Rosebay Willowherb [<i>Chamaenerion angustifolium</i> (L.) Scop.] Demonstrated on Model Plant Lettuce

Allelopathic plants are important resources for the discovery of bioherbicides. Rosebay willowherb [Chamaenerion angustifolium (L.) Scop. syn. Epilobium angustifolium L.] widely distributes in Western Asia, Europe, and North America, and behaves as a dominant species within the community due to the production of substances that restrict growth of other plants. This study aims at investigating the allelopathic potential of rosebay willowherb by evaluation of the effects of aqueous extracts from different parts on seed germination and seedling growth in lettuce (Lactuca sativa L.), as well as measuring the accumulation of reactive oxygen species and structural analysis of root tips via scanning electron and transmission electron microscopy. It was observed that the aqueous extracts from the leaves of rosebay willowherb had the strongest inhibitory effect on the germination index, germination energy and total germination of lettuce seeds, followed by capsular fruits and flowers, and the inhibition effect of stems was the weakest. All aqueous extracts (100 mg/mL) showed a significant inhibitory effect on radicle elongation of lettuce seedlings. Additionally, after treatment with the aqueous extract of rosebay willowherb leaves, accumulation of reactive oxygen species increased in columella cells, which correlated with disruption of root tip structure.     

几个树种枝叶水浸液处理杉木6年后其生物量及分配

分别用杉木、木荷、丝栗栲,马尾松枝叶不同浓度水浸液处理杉木6年后测定其各器官的生物量及其分配,结果表明丝栗栲,马尾松,木荷水浸液处理杉木6年后,各器官的生物量有不同程度的提高,随着浓度加大其促进作用增强,在低浓度时有利于皮、枝和枯枝落叶生物量分配率,高浓度时有利于叶、根、干的生物量分配率,杉木水浸液处理杉木6年后,各器官生物量有不同程度的降低,随着浓度加大其抑制作用增加,在低浓度时有利于叶、皮、根,枝和干等各器官生物量分配率,高浓度时有利于枯枝落叶生物量分配率。     

Anti-acetylcholinesterase activities of traditional Chinese medicine for treating Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss and cognitive impairment. It is the most common type of dementia in the ageing population due to a severe loss of cholinergic neurons in selected brain area. At present, acetylcholinesterase inhibitors (AChEI) are the first group of drugs approved by the FDA to treat mild to moderate Alzheimer's disease. Most of these drugs such as huperzine and galanthamine are originally isolated from plants. In this study, the AChE inhibitory activities from extracts of Chinese medicinal herbs that have traditionally been prescribed to treat insomnia and brain function disorders were examined in a 96-well plate assay based on Ellman's method. Both ethanol and aqueous extracts of 26 traditional Chinese medicinal herbs were tested. Inhibitory effects were expressed as the percentage of inhibition. For the herbal extracts that were shown to exert a significant inhibition, dose-dependent inhibitory assays were also performed. Ethanol and aqueous extracts of six herbs were found to have high AChE inhibitory activities in a dose-dependent manner. The IC(50) of these herbal extracts on inhibition of AChE are at around 5-85mum/ml. The results of this study indicate that there is a great potential to search for novel usage of these medicinal herbs for the treatment of AD.     

基于生态位理论的典型草原铁杆蒿种群化感作用

运用改进的Levins生态位宽度指数和Pianka生态位重叠指数,研究了典型草原草地建群种与优势种之间的生态竞争关系;并利用建群种(铁杆蒿)茎叶浸提液对不同优势种的化感种子进行发芽试验,分析铁杆蒿的化感潜力及其在封育草地中的生态地位.结果表明:封育草地中,本氏针茅的生态位最宽(0.99),其次为百里香(0.94)、铁杆蒿(0.82)和大针茅(0.76),赖草最窄(0.73);铁杆蒿与本氏针茅、本氏针茅与百里香、百里香与大针茅、铁杆蒿与百里香之间的生态位重叠值分别为0.90、0.95、0.94和0.86.不同浓度的铁杆蒿浸提液对植物的化感作用强度不同,表现为“低促高抑”.铁杆蒿浸提液对本氏针茅幼苗根系生长的化感促进作用要强于百里香,而对百里香幼苗芽生长的抑制作用要强于本氏针茅.甲醇浸提液的化感作用要强于水浸提液.铁杆蒿、本氏针茅、百里香和大针茅之间高的生态位重叠,说明该草地群落将继续向本氏针茅群落演替,铁杆蒿群落仅是一个重要的过渡演替阶段.铁杆蒿的化感作用在其中担负着驱动力的角色.     

Differential pathogenicity of two entomopathogenic bacteria,Photorhabdus temperata subsp. temperata and Xenorhabdus nematophila against the red flour beetle,Tribolium castaneum

Two entomopathogenic bacteria, Photorhabdus temperata subsp. temperata (Ptt) and Xenorhabdus nematophila (Xn), are symbiotically associated with the nematodes, Heterorhabdis megidis and Steinernema carpocapsae, respectively. There is little information on natural host ranges of the nematodes, but a significant difference in pathogenicity was observed between these two bacteria against the red flour beetle, Tribolium castaneum, in which Ptt exhibited more than six times higher pathogenicity than Xn. The pathogenic difference was not due to their inhibitory effect on phospholipase A₂ activity that is required for expression of immune response of T. castaneum. The culture broths of both bacterial species had insecticidal activities when injected into the hemocoel. When the bacterial culture broths were fractionated into aqueous and organic extracts, most insecticidal activity remained in the aqueous extracts. The aqueous extracts of two bacteria contained proteins which showed different profiles.     

反枝苋水浸提液与挥发油对黄瓜根尖的影响

采用悬空气法研究了在入侵植物反枝苋(Amaranthus retroflexus L.)水浸提液和挥发油作用下,黄瓜根缘细胞活性、根冠果胶甲基酯酶(PME)、根尖过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)以及丙二醛(MDA)含量的变化规律.结果表明:反枝苋水浸提液对黄瓜根的生长无显著性影响而挥发油显著抑制黄瓜根的生长,且随浓度增大抑制作用显著增强.PME活性随着水浸提液浓度的增大呈先上升后下降趋势,而随着挥发油浓度的升高呈现逐渐上升的趋势;水浸提液和挥发油均降低了对根缘细胞的存活率,这种抑制作用随浓度的增加而增大;随着处理液浓度增大,黄瓜根尖中MDA含量、CAT活性整体表现为增加,SOD活性先升高后降低,POD活性与对照差异不显著.反枝苋挥发油的化感效应大于水浸提液的化感效应.     

Anthelmintic efficacy of Achillea millifolium against gastrointestinal nematodes of sheep: in vitro and in vivo studies

Achillea millifolium Linn., commonly called 'Pehl-ghasa', is used by farmers in traditional animal health care as a vermifuge. The objective of this study was to evaluate the anthelmintic efficacy of crude aqueous extracts and crude ethanolic extracts of entire A. millifolium against the gastrointestinal nematodes of sheep. The worm motility inhibition assay was used for in vitro studies and faecal egg count reduction assay was used for in vivo studies. In vitro studies revealed significant anthelmintic effects of aqueous extracts and ethanolic extracts on live Haemonchus contortus worms (P < 0.05) as evident from their paralysis and/or death at 8 h post exposure. Aqueous extracts of A. millifolium resulted in a mean worm motility inhibition of 94.44%, while ethanolic extracts resulted in mean worm motility inhibition of 88.88%. The mean mortality index of aqueous extracts was 0.95 while for ethanolic extracts it was 0.9. The lethal concentration 50 was 0.05 mg ml(-1) for aqueous extracts and 0.11 mg ml(-1) for ethanolic extracts. The in vivo anthelmintic activity of aqueous and ethanolic extracts of A. millifolium demonstrated a maximum (88.40%) nematode egg count reduction in sheep treated with aqueous extracts at 2 g kg(-1) body weight on day 15 after treatment. Ethanolic extracts resulted in a maximum of 76.53% reduction in faecal egg counts on day 15 after treatment with 2 g kg(-1) body weight. Thus, the aqueous extracts exhibited greater anthelmintic activity under both in vitro and in vivo conditions, and could be due to the presence of water-soluble active principle/s in A. millifolium. It is concluded that the entire plant of A. millifolium possesses significant anthelmintic activity and could be a potential alternative for treating cases of helminth infections in ruminants.