Antivirus activity of Xiyanping Injection against Dengue virus serotype 2 in vitro and in vivo

Objective To evaluate the antivirus activity of Xiyanping Injection against Dengue virus serotype 2 (DENV2) in vitro and in vivo. Methods A human hepatoma cell line HepG2 was treated with Xiyanping Injection through different ways, including the direct inactivation of virus, the inhibition of virus entry, administration after virus exposure and combination of pre- and post-exposure administration. The supernatant and cells were harvested in different time point. Then the virus antigen positive cells were detected by indirect immunofluorescence assay (IFA), and the viral RNA was measured by quantitative real-time PCR (qPCR). Moreover, antiviral activity of Xiyanping Injection was further detected with the HepG2 transplanted SCID mice. The mice were intraperitoneally injected with different doses (1,2,4 mg/mouse) of Xiyanping Injection for 4 days following the challenge of DENV2. The organs and sera in different groups were sampled on the sixth day post infection. Then, the numbers of virus antigen positive cells in spleen, liver and sera of mice were detected by IFA, and the survival rate of each group was monitored for 14 days. Results Xiyanping Injection can inactivate DENV2 and inhibit the entry of DENV2 into cells. The replication of DENV2 was significantly inhibited by Xiyanping Injection with the aforementioned medication in a dose-dependent manner. Especially, the antivirus activity of Xiyanping Injection is superior to ribavirin injection in the early and late stage of virus infection. Attractively, Xiyanping can reduce the viral load in organs and sera, and improve the survival rate of experimental mice. Conclusion Xiyanping Injection, as a traditional Chinese herba. displayed obviously antivirus activity and wide safety range in vitro and in vivo . Our results indicate Xiyanping Injection might be a new candidate of antiviral drug for DENV infection. 摘要：目的 分别通过体外和体内实验研究喜炎平注射液对H型登革病毒( Dengue virus serotype 2, DENV2)的抗病 毒作用。 方法 体外实验以利巴韦林注射液作为阳性对照药物, 分别以灭活、抑制进人、治疗性给药以及预防联合维 持治疗的方式处理人肝癌细胞株HepG2细胞, 在不同时相点收获上清和细胞, 分别利用间接免疫荧光(indirect immunofluorescence assay, IFA)和实时荧光定量PCR(quantitative real-time PCR, qPCR)检测DENV2的病毒载量, 从而评价喜炎 平注射液的体外抗DENV2作用。体内实验以SCID小鼠为实验鼠, 腹腔注射HepG2细胞, 建立模型小鼠, 腹腔注射感染 DENV2,次日给予不同剂量(1、2、4mg/只）的喜炎平注射液, 连续给药4d,部分小鼠于感染第6日取材, 利用IFA检测实 验鼠脾、肝及血清中病毒载量, 并观察实验鼠的生存率。 结果 体外实验显示, 喜炎平注射液能够灭活DENV2,并抑制 DENV2进入细胞, 同时无论是治疗还是治疗联合预防给药, 均可对DENV2的复制具有良好的抑制作用, 即在病毒感染 早期及晚期, 喜炎平均可发挥抗病毒作用, 且优于利巴韦林。进一步在体内实验中同样显示喜炎平具有较好的抗病毒 作用, 可以降低实验鼠脾、肝及血清中病毒载量, 并可提高实验鼠的生存率。 结论 喜炎平注射液具有明显的抗 DENV2病毒的作用 , 可为DENV感染的治疗提供新的候选药物