甘草提取物与氯硝柳胺联合杀螺效果研究

Study of the molluscicidal action of a Glycyrrhiza uralensis Fisch.extract in combination with niclosamide

目的探讨甘草提取物与氯硝柳胺复配用药的灭螺效果,为氯硝柳胺的联合用药方案提供参考依据。方法采用室内浸杀法,观察氯硝柳胺与甘草提取物的抑螺效果,并将300mg/L和150mg/L的甘草提取物分别与不同浓度氯硝柳胺复配,在室温条件下浸泡钉螺24、48、72h,观察钉螺上爬及死亡情况,测定LC50值与增效比SR。结果氯硝柳胺浸泡钉螺24、48、72h后的LC50值分别为0.100、0.072和0.053mg/L;300mg/L甘草提取物与不同浓度的氯硝柳胺复配灭螺24、48、72h后的LC50值分别为0.029、0.017和0.011mg/L,增效比SR分别为3.45、4.24和4.82;150mg/L甘草提取物与不同浓度的氯硝柳胺复配后浸泡24、48、72h的LC50值分别为0.064、0.024和0.014mg/L,增效比SR分别为1.56、3.00和3.78。氯硝柳胺单独用药48h钉螺死亡率分别为78.9%、53.3%、32.2%、17.8%、11.1%和7.8%,与300mg/L甘草提取物联合用药48h钉螺死亡率分别为100%、83.3%、80.0%、53.3%、46.7%和23.3%,差异均有统计学意义(χ20.200=21.24,χ20.100=18.72,χ20.500=41.71,χ20.025=24.83,χ20.0125=27.69、χ20.00625=8.29,均P<0.01)。与150mg/L甘草提取物联合用药48h钉螺死亡率分别为100%、80.0%、56.7%、53.3%、43.3%和20.0%,差异均有统计学意义(χ20.200=21.24,χ20.100=14.4,χ20.500=10.89,χ20.025=24.83,χ20.0125=23.85、χ20.00625=5.62,均P<0.05)。结论甘草提取物具有显著抑制钉螺离水上爬的作用,与氯硝柳胺复配后能明显增强杀螺效果,减少氯硝柳胺的使用剂量,值得进一步研究应用。

Objective To investigate the molluscicidal action of a combination of a Glycyrrhiza uralensis Fitch.extract and niclosamide in order to provide evidence for combined drug therapy. Methods The immersion method was used in this study.In the laboratory,Oncomelania hupensis snails were immersed in a solution with different concentrations of niclosamide and Glycyrrhiza uralensis Fisch.extract at room temperature.After treatment for 24,48,and 72 h,climbing by and the mortality of O.hupensis were investigated and the LC50 and SR were determined.The same methods were then used to study a mixed solution of niclosamide and G.uralensis extract at a concentration of 300 or 150mg/L. Results The LC50 of the G.uralensis extract was 11 501,4 219.5,and 2 121.8mg/L,and the LC50 of niclosamide was0.100,0.072,and 0.053mg/L after treatment for 24,48,and 72 h,respectively.The LC50 of niclosamide decreased to0.029,0.017,and 0.011mg/L with an SR of 3.45,4.24,and 4.82 when combined with the G.uralensis extract at a concentration of 300mg/L.The LC50 of niclosamide decreased to 0.064,0.024,and 0.014mg/L with an SR of 1.56,3.00,3.78 when combined with the G.uralensis extract at a concentration of 150mg/L.With niclosamide alone,snail mortality was 78.9%,53.3%,32.2%,17.8%,11.1%,and 7.8% after treatment for 48 h.When niclosamide was combined with the G.uralensis extract at a concentration of 300 mg/L,snail mortality increased to 100%,83.3%,80.0%,53.3%,46.7%,and 23.3%.The difference in snail mortality was statistically significant（χ20.200=21.24,χ20.100=18.72,χ20.500=41.71,χ20.025=24.83,χ20.0125=27.69,χ20.00625=8.29,P〈0.01）.When niclosamide was combined with the G.uralensis extract at a concentration of 150mg/L,snail mortality increased to 100%,80.0%,56.7%,53.3%,43.3%,and 20.0%.The difference in snail mortality was statistically significant（χ20.200=21.24,χ20.100=14.4,χ2=10.89,χ20.025=24.83,χ20.0125=23.85,χ20.00625=5.62,P〈0.05）.The mixtures displayed better molluscicidal action andeffectively inhibited climbing by O.hupensis.The snail mortality rate differed significantly for niclosamide alone and niclosamide in combination with the G.uralensis extract（P〈0.01）. Conclusion The G.uralensis extract effectively inhibited climbing by O.hupensis and greatly enhanced the molluscicidal action of niclosamide.This finding warrants further study.