飞龙掌血抗A型流感病毒活性的鉴定

Identification of antiviral activity of Toddalia asiatica against influenza type A virus

目的:鉴定中药飞龙掌血体外抗流感病毒(A/PR/8/34H1N1)活性。方法:用四唑氮化合物(MTS)测定流感病毒诱导细胞病变(CPE)方法,初筛200余种中草药提取物抗A型流感病毒活性。复筛中样品的抗病毒活性被进一步用荧光定量聚合酶链反应(PCR)测试方法验证。结果:飞龙掌血在MTS方法和定量PCR中均显示很强的抗H1N1型流感病毒活性,半数有效剂量(EC50)在MTS方法和定量PCR中分别为4.7,0.9mg·L-1。毒性实验显示半数细胞毒剂量(CC50)为187.2mg·L-1,选择指数(SI)在定量PCR测试中大于206。药物作用时间实验显示飞龙掌血与病毒同时加入细胞可获得最佳抗病毒效果,病毒感染前、后24h加入飞龙掌血仍然具有一定抗病毒作用。结论:飞龙掌血可作为抗流感病毒候选治疗药物。

Objective: To identify antiviral activity of Toddalia asiatica against influenza virus type A in vitro. Method: More than two hundreds Chinese medicinal herb extracts were screened for antiviral activities against influenza A/PR/8/34 (H1N1) virus using 3-(4,5-dimerthylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay for virus induced cytopathic effect (CPE) in a primary screening. Positive samples were picked up and were subjected to quantitative real-time polymerase chain reaction (PCR) to quantify reduction of H1N1 virus genomic RNA. Result: Toddalia asiatica showed potent antiviral activities against H1N1 virus, with 50% effective concentration (EC50) value of 4.7 mg·L-1 in MTS assay and 0.9 mg·L-1 in quantitative PCR assay respectively. The cytotoxicity test of Toddalia asiatica generated a CC50 value of 187.2 mg·L-1 and a selective index (SI) larger than 206 in quantitative PCR. Although the best antiviral activity of Toddalia asiatica was observed with co-treatment of influenza virus infection, it remained effective even when administrated 24 h before and after the initiation of infection. Conclusion: The results suggested that Toddalia asiatica compound extract could be a candidate for anti-HlNl virus agent in the treatment of influenza.