抗IBV中药的筛选

Selection of Chinese herbal medicine for anti-infectious bronchitis virus

采用气管环组织培养法通过3种加药方式对贯众、黄芩等10种中药及复方组合进行了抗鸡传染性支气管炎病毒的筛选试验,并采用滴鼻法对SPF鸡攻毒建立鸡传染性支气管炎感染模型,应用筛选出的中药复方制剂对其进行预防和治疗试验,并进行病毒毒力测定。不同给药方式显示:将中药与病毒体外作用后接种TOC,除黄芪外,各单味中药和复方组合对IBV均具有不同程度的直接灭活作用,最小有效浓度均达到1/128以上,其中贯众达到1/4 096;在接种IBV前2 h以及接种IBV后2 h给药,黄芩、贯众、板蓝根、鱼腥草及复方中药均能明显抑制IBV的繁殖,最小有效浓度均达到1/256以上,其中贯众效果显著,达到1/2 048。人工感染防治试验显示:治疗组和预防组所分离到的病毒毒力均低于感染组,复方中药对感染传染性支气管炎病毒鸡的保护率为93.33%,治愈率为75%。表明该复方中药对鸡传染性支气管炎具有良好的预防作用和治疗作用,且预防效果强于治疗效果。

Experiment of 10 Chinese herbal medicines and complex prescription, such as Cyrtomium fortunei and Scutellaria baicalensis against IBV was carried out by three function manner with tracheal organ culture method. A model of infectious bronchitis was developed in SPF chickens by repeated intranasal infectious routes and then the experimental prevention and treatment with compound Chinese herbal medicine was conducted and the virulence of isolated virus was determined continuously. Different treating manner had different effects on TOC. All the Chinese herbal medicines except Astragalus membranaceus had direct anti-IBV action after mixed with virus in vitro,and the minimal effective concentration（MEC） were higher than 1/128,thereinto Cyrtomium fortunei was 1/4 096. Isatidis indigotica,Scutellaria baicalensis,Cyrtomium fortunei, Houttuynia cordata and complex prescription had significant inhibition effect on IBV when treated before or after TOC inoculated with IBV for 2 hours. The MEC were higher than 1/256, thereinto Cyrtomium fortunei was 1/2 048. The results of experimental prevention and treatment＂ showed that in the same day, virus virulence of the prevention group and the treatment group were lower than the infected＇control,so the compound Chinese herbal medicine could eliminated virus of infected chickens. The protection rate and cure rate of compound Chinese herbal medicine were 93.33% and 75%. The results indicated that the compound Chinese herbal medicine could prevent and treat infectious bronchitis and the prevention effect was better than the treatment effect.