Antiviral effect of Hyunggaeyungyo-tang on A549 cells infected with human coronavirus

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.