Botswana College of Agriculture, Private Bag 0027, Gaborone, Botswana.
Vet Parasitol. 2013 Oct 18;197(1-2):160-7. doi: 10.1016/j.vetpar.2013.07.004. Epub 2013 Jul 12.
The effect of condensed tannins (CT) extracted from forage plants from Botswana on the free-living stages of a number of species of gastrointestinal nematode parasites derived from infected sheep were investigated using in vitro assays. Fresh samples of five different plants (Viscum rotundifolium, Viscum verrucosum, Tapinanthus oleifolius, Grewia flava and Ipomoea sinensis) were collected over two summers (February 2009 and 2010). Fractionation of each crude extract on a Sephadex LH-20 column yielded low molecular weight phenolics and CT-containing fractions. The effect of each purified CT fraction on parasites was evaluated using either egg hatch, larval development or larval migration inhibition assays. Three gastrointestinal nematode species (Haemonchus contortus, Trichostrongylus colubriformis and Teladorsagia circumcincta) derived from infected sheep were evaluated in the study. CT from V. rotundifolium and I. sinensis fractions from samples collected in 2009 and 2010 did not inhibit larval development. However, CT isolated from V. verrucosum, T. oleifolius and G. flava collected in 2009 completely inhibited the development of all parasite species. These CT fractions were more potent in inhibiting larval development of H. contortus than fractions from the same plant species collected in 2010. However, a slight effect on larval migration was observed with some CT extracts. The results suggest that CT extracts of some forage plants from Botswana have anti-parasitic properties in vitro, and that further research is required to determine any in vivo efficacy from feeding the plants to goats in a field situation.
从博茨瓦纳的草料植物中提取的缩合单宁（CT）对来源于感染绵羊的一些胃肠道线虫寄生虫自由生活阶段的影响，通过体外试验进行了研究。在两个夏季（2009 年 2 月和 2010 年 2 月）采集了五种不同植物（Viscum rotundifolium、Viscum verrucosum、Tapinanthus oleifolius、Grewia flava 和 Ipomoea sinensis）的新鲜样本。对每个粗提取物在 Sephadex LH-20 柱上进行分级分离，得到低分子量酚类和含 CT 的部分。使用卵孵化、幼虫发育或幼虫迁移抑制试验评估每个纯化 CT 部分对寄生虫的影响。本研究评估了来源于感染绵羊的三种胃肠道线虫（扭毛线虫、圆线虫和卷曲泰勒虫）。2009 年和 2010 年采集的 V. rotundifolium 和 I. sinensis 样本的 CT 部分不抑制幼虫发育。然而，2009 年采集的 V. verrucosum、T. oleifolius 和 G. flava 的 CT 分离物完全抑制了所有寄生虫物种的发育。这些 CT 部分在抑制 H. contortus 的幼虫发育方面比同年采集的同一植物种的 CT 部分更有效。然而，一些 CT 提取物对幼虫迁移有轻微影响。结果表明，博茨瓦纳一些草料植物的 CT 提取物在体外具有抗寄生虫特性，需要进一步研究以确定在田间条件下给山羊喂食植物的任何体内功效。
