Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km 15.5 Carretera Mérida-Xmatkuil, Yucatán, Mérida C.P. 97315, Mexico.
INRAE UMR 1225 Interactions Hôte Agents Pathogènes, 23 Chemin des Capelles, Toulouse F31076, France.
Vet Parasitol. 2024 Jun;328:110184. doi: 10.1016/j.vetpar.2024.110184. Epub 2024 Apr 10.
This study applied the in vitro rumen exsheathment test (IVRET) to evaluate the exsheathment kinetics of Haemonchus contortus infective larvae (L) incubated in ruminal liquor (RL) containing acetone:water extracts of Acacia pennatula (AP), Gymnopodium floribundum (GF), Havardia albicans (HA) or Lysiloma latisiliquum (LL). The role of polyphenols in the biological activity of the evaluated extracts was also determined. Larvae were incubated in RL either alone or added with a different plant extract (AP, GF, HA, or LL) at 1200 μg/mL. Polyethylene glycol (PEG) was added to block polyphenols in each treatment (RL+PEG, AP+PEG, GF+PEG, HA+PEG, and LL+PEG). After incubation times of 0, 1, 3, 6, 9, and 24 h, the exsheathment process was stopped to count the number of ensheathed and exsheathed L. A Log-Logistic model was used to determine the L exsheathment kinetics in the different RL treatments. The inflection point of the respective kinetic curves, which indicates the time to reach 50 % exsheathed L (T), was the only parameter that differed when comparing the exsheathment models (99 % probability of difference). The T values obtained for GF, HA, and LL treatments (T = 7.11 - 7.58 h) were higher in comparison to the T of RL (5.72 h) (≥ 70 % probability of difference). The L incubated in RL added with GF, HA, and LL extracts delayed their exsheathment at 3 and 6 h of incubation (28.71 - 48.06 % exsheathment reduction) compared to the RL treatment. The T value for AP, AP+PEG, GF+PEG, HA+PEG, and LL+PEG were similar to RL and RL+PEG (T = 5.34 - 6.97 h). In conclusion, the IVRET can be used to identify plants with the potential to delay the exsheathment of H. contortus L in the ruminal liquor. The acetone:water extracts of G. floribundum, H. albicans, and L. latisiliquum delayed the T of H. contortus exsheathment, which was evident at 3 and 6 h of incubation in ruminal liquor. The observed exsheathment delay was attributed to the polyphenol content of the extracts.
本研究应用体外瘤胃液蜕膜试验（IVRET）评估在含有丙酮：水提取物的 Acacia pennatula（AP）、Gymnopodium floribundum（GF）、Havardia albicans（HA）或 Lysiloma latisiliquum（LL）瘤胃液中孵育的旋毛虫感染幼虫（L）的蜕膜动力学。还确定了多酚在评估提取物的生物活性中的作用。幼虫在 RL 中单独孵育或添加不同的植物提取物（AP、GF、HA 或 LL）1200μg/mL。在每个处理中添加聚乙二醇（PEG）以阻止多酚（RL+PEG、AP+PEG、GF+PEG、HA+PEG 和 LL+PEG）。孵育 0、1、3、6、9 和 24 h 后，停止蜕膜过程以计数包埋和蜕膜的 L 数量。使用对数逻辑模型确定不同 RL 处理中 L 的蜕膜动力学。各自动力学曲线的拐点，即达到 50%蜕膜 L 的时间（T），是比较蜕膜模型时唯一不同的参数（99%差异概率）。与 RL（T=5.72 h）相比，GF、HA 和 LL 处理的 T 值（T=7.11-7.58 h）更高（差异概率≥70%）。在 3 和 6 h 孵育时，与 RL 处理相比，GF、HA 和 LL 提取物孵育的 L 延迟了蜕膜（蜕膜减少 28.71-48.06%）（T=5.34-6.97 h）。AP、AP+PEG、GF+PEG、HA+PEG 和 LL+PEG 的 T 值与 RL 和 RL+PEG 相似。综上所述，IVRET 可用于鉴定潜在的植物，以延缓瘤胃液中 H. contortus L 的蜕膜。丙酮：水提取物的 G. floribundum、H. albicans 和 L. latisiliquum 延迟了 H. contortus 的蜕膜时间，这在 3 和 6 h 孵育时在瘤胃液中很明显。观察到的蜕膜延迟归因于提取物中的多酚含量。
