藏药甘青乌头抗单纯疱疹病毒Ⅱ型体内外作用研究

 目的探讨藏药甘青乌头抗单纯疱疹病毒Ⅱ型(HSV-2)的作用和机制。方法MTT法测定甘青乌头对Vero细胞的毒性,采用细胞病变法和蚀斑法测定甘青乌头体外抗病毒活性,以半数抑制浓度和治疗指数为评价指标;定量荧光PCR法和蚀斑法考察甘青乌头体外抗病毒作用机制。用HSV-2建立小鼠脑炎模型,对甘青乌头体内抗单纯疱疹病毒的抗病毒活性进行评价。结果甘青乌头对Vero细胞的半数中毒浓度(CC₅₀)为5.57 g·L^-1。细胞病变法和蚀斑法测得甘青乌头的半数有效浓度(EC₅₀)分别为2.25,1.68 g·L^-1,治疗指数TI分别为2.47,3.32。LD₅₀值为0.85 g·kg^-1。甘青乌头延长了小鼠的平均存活时间,对小鼠的死亡显示出10%的保护率。甘青乌头能直接灭活HSV-2,能够显著抑制HSV-2的感染性;对病毒吸附到细胞没有抑制作用,能抑制HSV-2大分子的增值。抑制HSV-2 DNA合成的抑制倍数达102。结论甘青乌头体外具有较强的抗HSV-2的活性,抗病毒作用是通过抑制病毒复制循环的各个环节起作用的。

Evaluation of Antiviral Activity of Tibetan Medicine Aconitum tanguticum Against Herpes Simplex Virus type Ⅱ in Vitro and in Vivo

OBJECTIVE To evaluate the antiviral effect and mechanisms of Tibetan herbal medicine A.tanguticum against Herpes simplex virus Ⅱ.METHODS The cytotoxicity was assayed by MTT colorimetry.The antiviral effective rate was investigated using cytopathic effect(CPE) and plaque reduction assay.50% effective concentration(EC₅₀) and treatment index(TI) were used to estimate the index of antiviral activity.The mode of action and molecular mechanism were investigated with real-time PCR and plaque reduction assay.Mouse model with herpes encephalitis was established to evaluate the antiviral efficacy in vivo.RESULTS The 50% cytotoxic concentration(CC50) value of A.tanguticum was 5.57 g·L^-1.The EC₅₀ values were 2.25 and 1.68 g·L^-1 using cytopathic effect method and plaque reduction assay respectively.The therapeutic indexes(TI) were 2.47 and 3.32,respectively.The LD₅₀ of A.tanguticum was 0.85 g·kg^-1.A.tanguticum prolonged mean survival times and the reduced protected rate of mice was 10%.A.tanguticum diminished virus infectivity significantly,while had no effect on virus attachment to Vero cell,and inhibited biosynthesis of HSV-2 in cells.A.tanguticum inhibited DNA replication of HSV-2 and produce 102 folds reduction in virus titre.CONCLUSION A.tanguticum possesses strong anti-HSV-2 activity in vitro.The antiviral mechanisms are related to different stage of virus replication.