Antiviral Effect of Hyunggaeyungyo-tang on A549 Cells Infected with Human Coronavirus

Abstract Background Herbal medicine is widely recommended to treat viral infectious diseases. Over 123,000,000 individuals have been infected with the coronavirus since a worldwide pandemic was declared in March 2020. We conducted this research to confirm the potential of herbal medicine as a treatment for coronavirus. Methods We infected the A549 cell line with beta coronavirus OC43 then treated with 100 μg/mL Hyunggaeyungyo-tang (HGYGT) or distilled water with a control of HGYGT. We measured the mRNA expression levels of pro-inflammatory cytokines and interferon stimulated genes (ISGs) to confirm the effectiveness of HGYGT upon coronavirus infection. Results We found the effects of HYGYT decrease the expression level of pPKR, peIF2α, IFI6, IFI44, IFI44L, IFI27, IRF7, OASL and ISG15 when administered to cells with coronavirus infection. The expressions of IL-1, TNF-α, COX-2, NF-κB, iNOS and IKK mRNA were also significantly decreased in the HGYGT group than in the control group. Conclusion Through the reduction of the amount of coronavirus RNA, our research indicates that HGYGT has antiviral effects. The reduction of IKK and iNOS mRNA levels indicate that HGYGT reduces coronavirus RNA expression and may inhibits the replication of coronavirus by acting on NF-kB/Rel pathways to protect oxidative injury. In addition, decreases in mRNA expression levels of pro-inflammatory cytokines indicate that the HGYGT may relieve the symptoms of coronavirus infections.