Abstract:

【Objective】 The purpose of the experiment is to research the effects of forsythoside A on the expression of IFN-α and Mx1 in the mouse model of PCV2 infection, and further to evaluate the antiviral activity of forsythoside A. 【Method】 The mouse models were established by infection with PCV2 and then divided into low, medium and high-dose groups, which were treated with 2, 4, 10 mg?mL-1 forsythoside A respectively, the blank control group and virus control group. Total RNA and total protein were extracted from the lung tissue of mouse in each group after 12, 24, 36 h administration. The mRNA content of IFN-α and Mx1 were detected by Real-time fluorescence quantitative PCR, and the expression of Mx1 protein was detected by Western blotting. 【Result】 IFN-α and Mx1 were no expressed in the lung tissue of mouse in the blank control group, and less expression was observed in the virus control group. With the concentration of forsythoside A increasing, the mRNA content of IFN-α and Mx1 gradually increased and parallelly correlated with each other. The highest expression of IFN-α and Mx1 was observed in the high-dose group (P＜0.001), the expression of IFN-α and Mx1 gradually decreased following the extension of time and reached the maximum after 12 h high-dose drug administration (P＜0.001). 【Conclusion】 The data showed that Kunming mice is suitable for the establishment of model which was infected with PCV2. Forsythoside A could promote the expression of IFN-α and Mx1 significantly, and played a significant antiviral activity after 12 h high-dose drug administration. It is concluded that Mx1 protein is closely related to the virus infection, and it can be used for early diagnosis of viral infection.

Key words: forsythoside A, IFN-α, Mx1, PCV2