Melia azedarach is commonly used in traditional and folk medicine in Korea and China to treat a variety of diseases including diarrheal, diabetic, rheumatic, and hypertensive disease. The aim of this study was to determine the potential prophylactic and therapeutic effects of Melia azedarach against a broad spectrum of viruses in in vitro cell culture model and the protective effect against different influenza A subtypes in BALB/c mice model. An effective dose of pre-treatment, co-treatment, and post-treatment of Melia azedarach significantly reduced the replication of coxsackievirus, herpes simplex virus, influenza A virus, enterovirus, and bovine rhinovirus in both epithelial and macrophage cell lines. Melia azedarach treatment remarkably promoted the phosphorylation of the key molecules associated with the type-1 interferon and NF-κB signaling pathways. Furthermore, it induced the secretion of type-1 interferon and pro-inflammatory cytokines and the subsequent stimulation of the antiviral state in both epithelial and macrophage cells. Interestingly, oral inoculation of an effective dose of herb extract significantly improved viral clearance in the lungs of BALB/c mice, thus exhibiting protection against several subtypes of influenza A virus. Together with our results indicate that an extracts of Melia azedarach and its components could exhibit a potential natural source of an antiviral drug candidate for a broad spectrum of viruses in animal and humans.

Introduction
Materials and Methods
    Preparation of Melia azedarach
    Cells and viruses
    Inhibition of virus replication in Melia azedarachtreated epithelial and macrophage cells
    Virus titration of treated cell and cell supernatant
    Detection of IFN-β and IL-6 in Melia azedarachtreated cells by enzyme-linked immunosorbentassay (ELISA)
    Quantitative RT-PCR (qRT-PCR)
    Effects of Melia azedarach on Type I IFN relatedprotein phosphorylation in RAW264.7 cells (Immunoblotanalysis)
    Oral administration of Melia azedarach and viralchallenge in BALB/c mice
    Lung virus titer
    Statistical analysis
Results
    Pre-treatment effect of Melia azedarach in differentcell lines
    Co-treatment effect of Melia azedarach in differentcell lines
    Post-treatment effect of Melia azedarach in differentcell lines
    Melia azedarach induces the secretion of IFNs, apro-inflammatory cytokine, and activates the signalingmolecules of the type I IFN and NF-κBsignaling pathway
    Melia azedarach induces IFN and pro-inflammatorycytokines gene transcription in the treated cells
    Orally-administrated Melia azedarach enhances thesurvival of influenza A virus-infected mice
Discussion
References

• N. A. Nadeeka Nethmini(College of Veterinary Medicine, Chungnam National University)
• Myun Soo Kim(R&D Division, VITABIO)
• Kiramage Chathuranga(College of Veterinary Medicine, Chungnam National University)
• Jin Yeul Ma(Korean Medicine (KM) Application Center, Korea Institute of Oriental Medicine)
• Hongik Kim(R&D Division, VITABIO)
• Jong-Soo Lee(College of Veterinary Medicine, Chungnam National University) Corresponding author