Background: To investigate the anti-influenza mechanism of punicalagin and its inhibitory effects on influenza virus proteins, we conducted molecular docking studies targeting 11 viral proteins. Additionally, molecular dynamics simulations were performed for the protein with the lowest free energy and the minimum concentration required for binding in a simulated environment. Methods: The molecular structure and data of punicalagin were obtained from the PubChem database and converted into a PDB file. FASTA sequences of viral proteins were retrieved from UniProt, and their PDB structures were predicted using the I-TASSER server. Molecular docking was performed using AutoDock 4.2 software, while molecular dynamics simulations were conducted with Gromacs 2022 software. Results: The PB1-F2 protein exhibited the best inhibitory performance, with a binding energy of -5.76 kcal/mol and the lowest inhibition constant (Ki). Docking of punicalagin to the PB1-F2 protein led to a significant decrease in the average total energy (TE), radius of gyration (Rg), and root mean square deviation (RMSD), as well as alterations in the secondary structure of the protein (P < 0.001). The most prominent secondary structural change was a reduction in coil structures and an increase in turn structures. Conclusions: Punicalagin displayed a strong binding affinity for the PB1-F2 protein compared to other influenza viral proteins. Considering the role of PB1-F2 in exacerbating inflammation caused by influenza, punicalagin may mitigate inflammation in patients by modulating the activity of this protein.
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