Copper-based drugs inhibit infectious bronchitis virus (IBV) in vitro and in vivo

Infectious bronchitis (IB) is an acute respiratory disease caused by the infectious bronchitis virus (IBV), spreads rapidly and manifests with diverse clinical signs, posing a major significant to the poultry industry. Metal ions such as copper are known to possess notable antiviral properties. Therefore, we evaluated the potential efficacy of copper-based pharmaceuticals against IBV. Results demonstrated that the copper-based drugs significantly protected DF-1 cells from IBV-M41 infection, markedly increasing cell activity and reducing IBV N-gene level. Furthermore, these drugs enhanced antiviral immunity and exhibited anti-apoptotic activity in vitro. In addition, these drugs increased the survival rates of infected chicken embryos and chicks while reducing developmental disruptions, thereby demonstrating robust antiviral effects. Pathological examinations revealed that lesions in the lungs, trachea, kidneys, spleen and other organs of treated groups improved to varying degrees, with a down-regulation of IBV N-gene level in chicks. Our study showed that the copper-based drugs exhibited anti-IBV-M41 both in vitro and in vivo, which provides a theoretical and experimental basis for exploring the anti-coronaviral effects of metal-based drug candidates.