Hesperetin blocks poxvirus replication by competitively inhibiting
binding of the 5' cap of viral mRNA with eIF4E
Abstract
In this study, hesperetin was shown to inhibit the replication of
multiple poxviruses, including buffalopox virus (BPXV), vaccinia virus,
and lumpy skin disease virus (LSDV). Hesperetin mainly suppressed viral
protein synthesis without affecting other steps of the viral life cycle
such as attachment, entry, and budding. In a chromatin
immunoprecipitation (CHIP) assay, we further demonstrated that
hesperetin-induced reduction in BPXV protein synthesis is due to
disruption of the binding of the 5’ cap of viral mRNA with the cellular
translation initiation factor eIF4E. The molecular docking and MD
simulation studies, also confirmed binding of the hesperetin with the
cap-binding pocket of eIF4E, in a similar conformation as m7GTP binds.
In a BPXV egg infection model, hesperetin was shown to suppress the
development of pock lesions on the chorioallantoic membrane, as well as
the associated mortality of the chicken embryos. Most importantly,
long-term culture of BPXV in the presence of hesperetin did not induce
the generation of drug-resistant viral mutants. In conclusion, we for
the first time demonstrated the antiviral activity of hesperetin against
poxviruses, besides providing novel mechanistic insights into the
antiviral action of hesperetin.