Hesperetin blocks poxvirus replication by competitively inhibiting binding of the 5' cap of viral mRNA with eIF4E

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.