连翘水提液体外对禽流感病毒增殖及炎症因子表达的抑制效应

旨在评估连翘体外抗H5N1和H9N2禽流感病毒（avian influenza viruses，AIVs）增殖及其介导炎症的效果，本试验制备了连翘水提液，首先采用CCK-8法测定了连翘水提液对DF-1细胞的安全浓度，并通过3种处理方法（药液预处理病毒后感染细胞、先感染病毒后给药、先给药后感染病毒）来筛选连翘水提液的最佳给药方式；在最佳给药方式下，使用TCID₅₀法检测禽流感病毒H5N1和H9N2的增殖情况，并采用qRT-PCR检测了炎症相关趋化因子和细胞因子的表达变化。结果显示，连翘水提液对DF-1细胞的最高安全浓度为4 mg·mL^-1；先感染病毒后给药是最佳的给药方式；在最佳给药方式下，连翘水提液能显著降低H5N1和H9N2 AIVs在各个时间点的病毒滴度，并呈剂量依赖性关系；与对照组相比，H5N1 AIV给药组中CX3CL1、IL8L1、CCL5、SCYA4、IL1β、IL-6和TNF-α的表达显著降低，H9N2 AIV给药组中CX3CL1、IL8L1、CCL5、IFN-β、IL-6和TNF-α的表达也有类似的下降趋势。这表明连翘能够抑制H5N1和H9N2 AIVs在DF-1细胞中的增殖，降低炎症相关细胞因子的表达，有良好的抗炎和抗病毒活性。

Inhibitory Effect of Forsythiae Fructus Aqueous Extracts on the Proliferation of Avian Influenza Virus and the Expression of Inflammation Factors in vitro

To evaluate the effect of Forsythia Fructus on the proliferation of H5N1 and H9N2 avian influenza viruses(AIVs) and their mediated inflammation in vitro. The aqueous extract of Forsythiae Fructus was prepared in this experiment, and CCK-8 method was used to examine the cytotoxicity of Forsythiae Fructus aqueous extract to DF-1 cells, firstly. Three methods of treatments including infection after co-incubation of the AIVs and Forsythiae Fructus aqueous extract, treatment of cells by Forsythiae Fructus aqueous extract post virus infection and administration method treatment of cells by Forsythiae Fructus aqueous extract prior to virus inoculation were used to screen the optimal administration method of the of Forsythiae Fructus aqueous extract. TCID₅₀ method was used to detect the proliferation of H5N1 and H9N2 avian influenza viruses and the expression changes of inflammatory chemokines and cytokines were detected by qRT-PCR under the optimal administration method. The results indicated that Forsythiae Fructus aqueous extract showed no cytotoxicity to DF-1 cells below the concentration of 4 mg·mL^-1 and treatment of Forsythiae Fructus aqueous extract post virus infection was the optimal administration method. Forsythiae Fructus aqueous extract significantly reduced the virus titers of H5N1 and H9N2 AIVs at various time points in a concentration-dependent manner. The expression of CX3CL1, IL8L1, CCL5, SCYA4, IFN-α, IL-1β, IL-6 and TNF-α decreased significantly in H5N1 AIV treated by the aqueous extract group compared with the control. While in H9N2 AIV group, the expression of CX3CL1, IL8L1, CCL5, IFN-β, IL-6 and TNF-α showed a similar trend. These results indicated that Forsythiae Fructus has shown promising antiviral and antiinflammation activity by inhibiting the proliferation of H5N1 and H9N2 AIVs in DF-1 cells and reducing the expression of inflammation related cytokine genes.