Marek’s disease virus (MDV) is a member of alpha-herpes virus subfamily, and serotype 1 strains are the etiologic agentof Marek’s disease (MD), which is a highly contagious and infectious malignant lymphoid neoplastic disease. MD is a neoplastic disease of chickens and other gallinaceous birds. It is one of the major diseases that threatens poultry industry worldwide and causes heavy economic losses [1]. Current report showed that half of the world countries had case reports of MDV infection [2]. In recent years, many reports of the onset of MDV have also been declared in vaccinated chickens [3,4,5,6]. The virulence of MDV has been continuously evolved and gradually increased under the pressure of vaccination. In MD vaccine can prevent tumorigenesis and immunosuppression, but the virus can still replicate into fully infectious virus particles and shed cell free mature virions through skin dander and dust. Thus, the ideal MDV vaccine would be capable of controlling the replication of MDV in chickens and stopping the shedding of virions [2].
Traditional Chinese Medicine (TCM) has been widely used to treat and prevent illnesses for thousands of years. Baicalin, a flavonoid compound, is the main effective component of Scutellaria baicalensis Georgi which is one of the commonly used herbal medicine in China [7]. Previous studies have reported that baicalin exibited inhibitory effects against Herpes simplex virus 1 (HSV-1) [8]. It could inactivate free Dengue virus (DENV) particles and interfere with intracellular viral replication by affecting the attachment of DENV to host cells [9]. As a neuraminidase (NA) inhibitor, it had anti-influenza A virus infection activity [10]. It could also directly kill Newcastle disease virus (NDV) and block intracellular NDV replication. In our previous report, we showed that baicalin had antiviral effect on avian leukosis virus subgroup J through targeting virus internalization [11]. However, the inhibitory effects of baicalin on MDV infected CEF cells were not evaluated. Therefore, the present study focused on the antiviral properties of baicalin and its mechanism against MDV replication in CEFs.