苦楝提取物对捻转血矛线虫卵和幼虫活性的影响

Effect of Melia azedarach Extract on the Egg and Larva Activity of Haemonchus contortus

为初步探讨苦楝对捻转血矛线虫的作用,本试验通过观察苦楝提取物对虫卵和幼虫活性及形态变化的影响,评估其对捻转血矛线虫的驱虫活性,以期为家畜捻转血矛线虫病的防控及植物驱虫药物的研发奠定基础。试验对苦楝水提取物和乙醇提取物设置5个浓度(25、12.5、6.25、3.125、1.562 mg/mL)进行虫卵孵化试验和幼虫活性试验,对不同浓度药物处理的虫卵及幼虫进行计数,并观察药物作用后虫卵和幼虫的孵化状态及形态变化。结果显示,正常孵育的虫卵和幼虫活力良好,苦楝提取物作用48 h后,虫卵呈未孵化、半孵化状态,发育至桑葚期、蝌蚪期及幼虫期死亡,并且各浓度苦楝水提物和醇提物对虫卵均具有抑制作用,其中苦楝皮醇提物对虫卵孵化的抑制效果最佳,在浓度25 mg/mL时,对虫卵孵化的抑制率高达98.2%,在12.5 mg/mL时,苦楝子醇提物对虫卵的抑制率极显著高于苦楝皮醇提取物(P<0.01)。苦楝子提取物对感染性三期幼虫的致死效果较差,在50 mg/mL时对幼虫有较高致死率(82.6%)。苦楝皮水提取物在浓度为50 mg/mL时对幼虫的致死效果尤为突出,幼虫死亡率为97.0%,死亡的幼虫呈“直线型”或“弓型”。经方差分析,在12.5~50 mg/mL浓度范围内,相同浓度苦楝水提取物之间的致死率存在显著或极显著差异(P<0.05;P<0.01),同浓度苦楝醇提取物对幼虫的致死率存在极显著性差异(P<0.01)。综上所述,苦楝提取物对体外的捻转血矛线虫卵和感染性三期幼虫的活性均有抑制作用,其中25 mg/mL苦楝皮醇提物对虫卵孵化的抑制效果最佳,50 mg/mL苦楝皮水提物对感染性三期幼虫的致死作用最好。

In order to study the effect of Melia azedarach on Haemonchus contortus,this experiment was to observe the effect of Melia azedarach extract on the activity and morphological changes of eggs and larvae,and to evaluate its repellent activity on Haemonchus contortus,so as to lay a foundation for the prevention and control of Haemonchus contortus disease in domestic animals and the research and development of plant repellents.In the experiment,5 concentrations(25,12.5,6.25,3.125 and 1.562 mg/mL)of water extract and ethanol extract of Melia azedarach were set for egg hatching test and larva activity test.The eggs and larva treated with different concentrations of drugs were counted,and the hatching state and morphological change of eggs and larva were observed after the action of drugs.The results showed that the activity of the eggs and larvae was good.48 h after the action of Melia azedarach extract,the eggs were in the state of non hatching and half hatching,and developed to the stage of mulberry,tadpole and larval death.The water extract and alcohol extract of Melia azedarach at different concentrations inhibited the hatching of the eggs,and the inhibitory effect of alcohol extract of Meliae on the hatching of the eggs was the best.At the concentration of 25 mg/mL,the alcohol extract of Meliae inhibited the hatching of the eggs,and the inhibition rate of hatching was 98.2%.At 12.5 mg/mL,the inhibitory rate of wormwood extract on worm eggs was significantly higher than that of oxydermal extract(P<0.01).The lethal effect of Melia azedarach seed extract on infective third stage larvae was poor,only at 50 mg/mL,it had a higher lethal rate to larvae,and the mortality rate was 82.6%.When the concentration of water extract of Meliae was 50 mg/mL,its lethal effect on larva was particularly prominent,the mortality rate of larva was 97.0%,and the dead larva was“linear”or“bow”.By variance analysis,in the range of 12.5 to 50 mg/mL,there was a significant or extremely significant difference in the lethality rate between the water extracts of Melia azedarach at the same concentration(P<0.05;P<0.01).There were extremely significant differences in lethal rate of larva between the alcohol extract at the same concentration(P<0.01).In conclusion,Melia azedarach extract could inhibit the activity of eggs and infective third stage larvae of Haemonchus twist in vitro.Among them,25 mg/mL Meliae alcohol extract had the best inhibitory effect on egg hatching,and 50 mg/mL Meliae water extract had the best lethal effect on infective third stage larvae.