香豆素化合物体内外抗狂犬病病毒的效果

Inhibition of rabies virus by coumarin in vitro and in vivo

狂犬病是由狂犬病病毒(rabies virus,RABV)引起的一种以侵害中枢神经系统为特征的高度致死性人兽共患传染病,虽然人类尝试了多种方法用于治疗狂犬病,但到目前为止,狂犬病一旦出现临床症状,死亡率仍高达100%,因此,寻找有效的抗RABV药物仍是亟待解决的问题。已有研究显示香豆素化合物(coumarin,CM)具有一定的抗病毒作用,但其对RABV的作用目前尚没有研究。首先以BHK-21细胞为模型,通过SRB、直接免疫荧光(DFA)和病毒滴度等方法,在体外筛选具有良好抗RABV作用的CM,进而从直接灭活、阻滞吸附、不同时间点对病毒抑制效果等方面探讨CM体外抗RABV的作用机制。随后构建RABV感染动物模型,观察筛选获得的CM是否可以挽救病毒感染小鼠。结果显示,CM-3(9种CM分别标记为CM-1～9)可以有效抑制RABV在宿主细胞内的复制,但不能直接灭活病毒,也不能阻滞RABV对宿主细胞的吸附;其在RABV感染48h内均可以显著抑制病毒复制,最高抑制率可达60.0%。另外,结果显示在RABV感染后3～12h内用药,CM-3的抑制效果更为显著,抑制率均为50.0%以上;随后,通过体内试验证实CM-3(50mg/kg)可将感染小鼠的存活率由0%提高至12.5%。综上,结果提示,CM-3可能通过感染后抑制病毒复制的方式发挥抗RABV的作用,而此类结构的CM有可能作为潜在的药物用于狂犬病的治疗。

Rabies is a lethal zoonotic disease which is caused by rabies virus(RABV)and died of fatal encephalitis.Although explored several methods to treat the rabies,the mortality is still around 100%once central nervous was infected and developed symptoms.Treatment of rabies remains a major challenge,therefore,requires the development of alternative strategies.Coumarin(CM)compounds have shown antiviral effects on HIV and HSV,the present study investigated its potency against infection of RABV.By using SRB,direct immunofluorescence(DFA),TCID50,qRTPCR,CM-3displayed an effectively inhibit of RABV replication in vitro,delined by 60%to the lowest within 48hpost infection,although it did not inactivate the virus directly or block the virus adsorption in host cells.Additionally,CM-3potential inhibitory effect could reach more than 50%even though the post infection 12h.After that,in vivo experiment confirmed that CM-3(50mg/kg)moderately alleviated the clinical symptoms and RABV related mortality of infected mice increased by 12.5%.Our results indicated that CM-3has an effective anti-RABV activity by inhibiting viral replication of post infection,and might be used as a potential candidate to develop an anti-RABV drug.