{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,8]],"date-time":"2025-11-08T13:26:31Z","timestamp":1762608391222,"version":"build-2065373602"},"reference-count":28,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2021,8,15]],"date-time":"2021-08-15T00:00:00Z","timestamp":1628985600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100010798","name":"Sunway University","doi-asserted-by":"publisher","award":["N\/A"],"award-info":[{"award-number":["N\/A"]}],"id":[{"id":"10.13039\/501100010798","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011821","name":"Ministry of Higher Education","doi-asserted-by":"publisher","award":["FRGS\/1\/2018\/SKK11\/SYUC\/03\/3"],"award-info":[{"award-number":["FRGS\/1\/2018\/SKK11\/SYUC\/03\/3"]}],"id":[{"id":"10.13039\/501100011821","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Enterovirus A71 (EV-A71) is a major neurovirulent agent capable of causing severe hand, foot and mouth disease (HFMD) associated with neurological complications and death. Currently, no FDA-approved antiviral is available for the treatment of EV-A71 infections. The flavonoid silymarin was shown to exert virucidal effects, but the binding site on the capsid was unknown. In this study, the ligand interacting site of silymarin was determined in silico and validated in vitro. Moreover, the potential of EV-A71 to develop resistance against silymarin was further evaluated. Molecular docking of silymarin with the capsid of EV-A71 indicated that silymarin binds to viral protein 1 (VP1) of EV-A71, specifically at the GH loop of VP1. The in vitro binding of silymarin with VP1 of EV-A71 was validated using recombinant VP1 through ELISA competitive binding assay. Continuous passaging of EV-A71 in the presence of silymarin resulted in the emergence of a mutant carrying a substitution of isoleucine by threonine (I97T) at position 97 of the BC loop of EV-A71. The mutation was speculated to overcome the inhibitory effects of silymarin. This study provides functional insights into the underlying mechanism of EV-A71 inhibition by silymarin, but warrants further in vivo evaluation before being developed as a potential therapeutic agent.<\/jats:p>","DOI":"10.3390\/ijms22168757","type":"journal-article","created":{"date-parts":[[2021,8,15]],"date-time":"2021-08-15T21:43:55Z","timestamp":1629063835000},"page":"8757","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Functional Insights into Silymarin as an Antiviral Agent against Enterovirus A71 (EV-A71)"],"prefix":"10.3390","volume":"22","author":[{"given":"Salima","family":"Lalani","sequence":"first","affiliation":[{"name":"Centre for Virus and Vaccine Research, Sunway University, Subang Jaya 47500, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Malihe","family":"Masomian","sequence":"additional","affiliation":[{"name":"Centre for Virus and Vaccine Research, Sunway University, Subang Jaya 47500, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8475-6291","authenticated-orcid":false,"given":"Chit Laa","family":"Poh","sequence":"additional","affiliation":[{"name":"Centre for Virus and Vaccine Research, Sunway University, Subang Jaya 47500, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Lalani, S., and Poh, C.L. (2020). Flavonoids as Antiviral Agents for Enterovirus A71 (EV-A71). Viruses, 12.","DOI":"10.3390\/v12020184"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"534","DOI":"10.1006\/bbrc.2000.3485","article-title":"Flavonoid baicalin inhibits HIV-1 infection at the level of viral entry","volume":"276","author":"Li","year":"2000","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"5452","DOI":"10.1038\/srep05452","article-title":"Baicalin, a metabolite of baicalein with antiviral activity against dengue virus","volume":"4","author":"Moghaddam","year":"2014","journal-title":"Sci. Rep."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1016\/j.virol.2016.06.012","article-title":"The green tea molecule EGCG inhibits Zika virus entry","volume":"496","author":"Carneiro","year":"2016","journal-title":"Virology"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"6816","DOI":"10.1016\/j.bmc.2009.08.036","article-title":"Neuraminidase inhibitory activities of flavonols isolated from Rhodiola rosea roots and their in vitro anti-influenza viral activities","volume":"17","author":"Jeong","year":"2009","journal-title":"Bioorg. Med. Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"11334","DOI":"10.1128\/JVI.78.20.11334-11339.2004","article-title":"Small molecules blocking the entry of severe acute respiratory syndrome coronavirus into host cells","volume":"78","author":"Yi","year":"2004","journal-title":"J. Virol."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Wu, W., Li, R., Li, X., He, J., Jiang, S., Liu, S., and Yang, J. (2016). Quercetin as an antiviral agent inhibits influenza A virus (IAV) entry. Viruses, 8.","DOI":"10.3390\/v8010006"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1016\/j.antiviral.2007.03.008","article-title":"In vitro anti-HIV and -HSV activity and safety of sodium rutin sulfate as a microbicide candidate","volume":"75","author":"Tao","year":"2007","journal-title":"Antivir. Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1255","DOI":"10.1016\/j.phytochem.2009.06.003","article-title":"Elderberry flavonoids bind to and prevent H1N1 infection in vitro","volume":"70","author":"Roschek","year":"2009","journal-title":"Phytochemistry"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"286","DOI":"10.3389\/fmicb.2018.00286","article-title":"Enterovirus A71 Proteins: Structure and Function","volume":"9","author":"Yuan","year":"2018","journal-title":"Front. Microbiol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1644","DOI":"10.1021\/jm010536a","article-title":"Design, Synthesis, and Structure\u2212Activity Relationship of Pyridyl Imidazolidinones: A Novel Class of Potent and Selective Human Enterovirus 71 Inhibitors","volume":"45","author":"Shia","year":"2002","journal-title":"J. Med. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"6990","DOI":"10.1128\/AAC.03328-14","article-title":"The Capsid Binder Vapendavir and the Novel Protease Inhibitor SG85 Inhibit Enterovirus 71 Replication","volume":"58","author":"Tijsma","year":"2014","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Sun, L., Lee, H., Thibaut, H.J., Lanko, K., Rivero-Buceta, E., Bator, C., Martinez-Gualda, B., Dallmeier, K., Delang, L., and Leyssen, P. (2019). Viral engagement with host receptors blocked by a novel class of tryptophan dendrimers that targets the 5-fold-axis of the enterovirus-A71 capsid. PLoS Pathog., 15.","DOI":"10.1371\/journal.ppat.1007760"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3523","DOI":"10.1128\/AAC.48.9.3523-3529.2004","article-title":"Mutation in Enterovirus 71 Capsid Protein VP1 Confers Resistance to the Inhibitory Effects of Pyridyl Imidazolidinone","volume":"48","author":"Shih","year":"2004","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/j.antiviral.2017.04.006","article-title":"Characterization of three small molecule inhibitors of enterovirus 71 identified from screening of a library of natural products","volume":"143","author":"Li","year":"2017","journal-title":"Antivir. Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s12906-020-2880-2","article-title":"Antiviral activity of silymarin in comparison with baicalein against EV-A71","volume":"20","author":"Lalani","year":"2020","journal-title":"BMC Complement. Med. Ther."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"eaar5759","DOI":"10.1126\/scitranslmed.aar5759","article-title":"Prunin suppresses viral IRES activity and is a potential candidate for treating enterovirus A71 infection","volume":"11","author":"Gunaseelan","year":"2019","journal-title":"Sci. Transl. Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1016\/j.antiviral.2014.06.004","article-title":"Apigenin inhibits enterovirus 71 replication through suppressing viral IRES activity and modulating cellular JNK pathway","volume":"109","author":"Lv","year":"2014","journal-title":"Antivir. Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"424","DOI":"10.1038\/nsmb.2255","article-title":"A sensor-adaptor mechanism for enterovirus uncoating from structures of EV71","volume":"19","author":"Wang","year":"2012","journal-title":"Nat. Struct. Mol. Biol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"12084","DOI":"10.1128\/JVI.02189-15","article-title":"Single Neutralizing Monoclonal Antibodies Targeting the VP1 GH Loop of Enterovirus 71 Inhibit both Virus Attachment and Internalization during Viral Entry","volume":"89","author":"Ku","year":"2015","journal-title":"J. Virol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"692","DOI":"10.1007\/s13238-014-0087-3","article-title":"Molecular mechanism of SCARB2-mediated attachment and uncoating of EV71","volume":"5","author":"Dang","year":"2014","journal-title":"Protein Cell"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Cordey, S., Petty, T.J., Schibler, M., Martinez, Y., Gerlach, D., Van Belle, S., Turin, L., Zdobnov, E., Kaiser, L., and Tapparel, C. (2012). Identification of Site-Specific Adaptations Conferring Increased Neural Cell Tropism during Human Enterovirus 71 Infection. PLOS Pathog., 8.","DOI":"10.1371\/journal.ppat.1002826"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"9969","DOI":"10.1128\/JVI.73.12.9969-9975.1999","article-title":"Molecular Epidemiology and Evolution of Enterovirus 71 Strains Isolated from 1970 to 1998","volume":"73","author":"Brown","year":"1999","journal-title":"J. Virol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.virol.2016.11.009","article-title":"VP1 residues around the five-fold axis of enterovirus A71 mediate heparan sulfate interaction","volume":"501","author":"Tan","year":"2017","journal-title":"Virology"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2518","DOI":"10.1099\/vir.0.2008\/002915-0","article-title":"Characterization of pharmacologically active compounds that inhibit poliovirus and enterovirus 71 infectivity","volume":"89","author":"Arita","year":"2008","journal-title":"J. Gen. Virol."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Qing, J., Wang, Y., Sun, Y., Huang, J., Yan, W., Wang, J., Su, D., Ni, C., Li, J., and Rao, Z. (2014). Cyclophilin A Associates with Enterovirus-71 Virus Capsid and Plays an Essential Role in Viral Infection as an Uncoating Regulator. PLoS Pathog., 10.","DOI":"10.1371\/journal.ppat.1004422"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1186\/s12985-017-0895-1","article-title":"Geraniin extracted from the rind of Nephelium lappaceum binds to dengue virus type-2 envelope protein and inhibits early stage of virus replication","volume":"14","author":"Ahmad","year":"2017","journal-title":"Virol. J."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1016\/j.jviromet.2013.06.007","article-title":"Validation of a cell-based ELISA as a screening tool identifying anti-alphavirus small-molecule inhibitors","volume":"193","author":"Spurgers","year":"2013","journal-title":"J. Virol. Methods"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/22\/16\/8757\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:46:34Z","timestamp":1760165194000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/22\/16\/8757"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,8,15]]},"references-count":28,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2021,8]]}},"alternative-id":["ijms22168757"],"URL":"https:\/\/doi.org\/10.3390\/ijms22168757","relation":{},"ISSN":["1422-0067"],"issn-type":[{"type":"electronic","value":"1422-0067"}],"subject":[],"published":{"date-parts":[[2021,8,15]]}}}