{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,28]],"date-time":"2026-10-28T22:22:23Z","timestamp":1793226143284,"version":"4.5.0"},"reference-count":40,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,8,13]],"date-time":"2025-08-13T00:00:00Z","timestamp":1755043200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>Dengue virus (DENV), a mosquito-borne flavivirus, leads to over 390 million annual infections worldwide, and there are no approved antivirals so far. Rhododendron mariae (RM), a traditional Chinese herb abundant in flavonoids and triterpenoids, is used to treat respiratory disorders, yet its antiviral potential has been little explored. This study sought to assess the activity and mechanism of RM-1, an extract from RM, against DENV.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>In vitro, plaque reduction assays in BHK-21 cells were used to determine RM-1\u2019s half-maximal effective concentration (EC50) against DENV-2. Its broad-spectrum activity against the four DENV serotypes was tested in Vero and Huh7 cells. In vivo, DENV-infected suckling mice were given RM-1 (10 mg\/kg), with monitoring of viral loads, histology, and survival. Mechanistic studies included attachment assays and molecular docking to find potential targets.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>RM-1 strongly inhibited DENV-2 (EC50=2.24 \u03bcg\/mL) and showed dose-dependent activity against all four serotypes by blocking viral attachment. In infected mice, RM-1 lessened disease severity, reduced tissue lesions, lowered viral loads in serum, brain and spleen, and boosted survival rates. It targeted DENV envelope protein domain III (ED III), which is critical for host attachment.<\/jats:p><\/jats:sec><jats:sec><jats:title>Discussion<\/jats:title><jats:p>This is the first report that RM-1 acts as a novel DENV attachment inhibitor by targeting ED III. These findings show RM-1\u2019s promise as an anti-dengue therapeutic, supporting traditional herbs as sources of antivirals for flavivirus drug development.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fimmu.2025.1663878","type":"journal-article","created":{"date-parts":[[2025,8,13]],"date-time":"2025-08-13T04:15:57Z","timestamp":1755058557000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Identification of Rhododendron mariae extraction as a new attachment inhibitor against dengue virus by targeting the envelope protein domain III"],"prefix":"10.3389","volume":"16","author":[{"given":"Chunyang","family":"Tian","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuanru","family":"Zheng","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dongkai","family":"Tang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haiyan","family":"Tian","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lingzhu","family":"Shi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xuemei","family":"He","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianhai","family":"Yu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lijun","family":"Yan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huihui","family":"Cao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Zhao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junshan","family":"Liu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Linzhong","family":"Yu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zibin","family":"Lu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,8,13]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(14)60572-9","article-title":"Dengue","volume":"385","author":"Guzman","year":"2015","journal-title":"Lancet"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1002\/cyto.a.24047","article-title":"Dengue fever, COVID-19 (SARS-coV-2), and antibody-dependent enhancement (ADE): A perspective","volume":"97","author":"Ulrich","year":"2020","journal-title":"Cytometry A"},{"key":"B3","doi-asserted-by":"publisher","first-page":"54","DOI":"10.1016\/j.bcp.2018.04.008","article-title":"Dengue virus NS2 and NS4: Minor proteins, mammoth roles","volume":"154","author":"Gopala Reddy","year":"2018","journal-title":"Biochem Pharmacol"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1038\/nature12060","article-title":"The global distribution and burden of dengue","volume":"496","author":"Bhatt","year":"2013","journal-title":"Nature"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2011.07.022","article-title":"The pathogenesis of dengue","volume":"29","author":"Whitehorn","year":"2011","journal-title":"Vaccine"},{"key":"B6","doi-asserted-by":"publisher","first-page":"6803098","DOI":"10.1155\/2016\/6803098","article-title":"Dengue fever: causes, complications, and vaccine strategies","volume":"2016","author":"Khetarpal","year":"2016","journal-title":"J Immunol Res"},{"key":"B7","doi-asserted-by":"publisher","first-page":"79","DOI":"10.13728\/j.1673-6427.2018.02.022","article-title":"The research progress of rhododendron mariae","volume":"32","author":"Xia","year":"2018","journal-title":"Chin Med J Res Prac"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.3321\/j.issn:1001-5302.2009.07.019","article-title":"Analysis of flavonoids in Rhododendron mariae by UPLC\/Q-TOF-MS","volume":"34","author":"Huang","year":"2009","journal-title":"Zhongguo Zhong Yao Za Zhi"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1039\/C7OB01055A","article-title":"Isolation and identification of l\/d-lactate-conjugated bufadienolides from toad eggs revealing lactate racemization in amphibians","volume":"15","author":"Zhou","year":"2017","journal-title":"Org Biomol Chem"},{"key":"B10","doi-asserted-by":"publisher","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":"B11","doi-asserted-by":"publisher","DOI":"10.1016\/j.antiviral.2018.11.011","article-title":"Tomatidine, a novel antiviral compound towards dengue virus","volume":"161","author":"Diosa-Toro","year":"2019","journal-title":"Antiviral Res"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1016\/j.phymed.2018.03.018","article-title":"Tatanan A from the Acorus calamus L. root inhibited dengue virus proliferation and infections","volume":"42","author":"Yao","year":"2018","journal-title":"Phytomedicine"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1111\/bph.14129","article-title":"Shikonin inhibits myeloid differentiation protein 2 to prevent LPS-induced acute lung injury","volume":"175","author":"Zhang","year":"2018","journal-title":"Br J Pharmacol"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1016\/j.lfs.2018.03.033","article-title":"Cappariloside A shows antiviral and better anti-inflammatory effects against influenza virus via regulating host IFN signaling, in vitro and vivo","volume":"200","author":"Li","year":"2018","journal-title":"Life Sci"},{"key":"B15","doi-asserted-by":"publisher","first-page":"14","DOI":"10.1016\/j.bcp.2017.01.005","article-title":"Pharmacological intervention for dengue virus infection","volume":"129","author":"Lai","year":"2017","journal-title":"Biochem Pharmacol"},{"key":"B16","doi-asserted-by":"publisher","first-page":"323","DOI":"10.20944\/preprints201908.0057.v1","article-title":"Hijacking the host immune cells by dengue virus: molecular interplay of receptors and dengue virus envelope","volume":"7","author":"Begum","year":"2019","journal-title":"Microorganisms"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1005277","article-title":"Dengue virus non-structural protein 1 modulates infectious particle production via interaction with the structural proteins","volume":"11","author":"Scaturro","year":"2015","journal-title":"PLoS Pathog"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1016\/j.antiviral.2017.02.015","article-title":"AR-12 suppresses dengue virus replication by down-regulation of PI3K\/AKT and GRP78","volume":"142","author":"Chen","year":"2017","journal-title":"Antiviral Res"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.3390\/molecules26010005","article-title":"Andrographolide, an anti-inflammatory multitarget drug: all roads lead to cellular metabolism","volume":"26","author":"Burgos","year":"2020","journal-title":"Molecules (Basel Switzerland)"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.3390\/molecules25215037","article-title":"Andrographolide and its 14-aryloxy analogues inhibit zika and dengue virus infection","volume":"25","author":"Li","year":"2020","journal-title":"Molecules (Basel Switzerland)"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1093\/femsre\/fuu004","article-title":"Receptors and routes of dengue virus entry into the host cells","volume":"39","author":"Cruz-Oliveira","year":"2015","journal-title":"FEMS Microbiol Rev"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.02367-17","article-title":"The amphibian antimicrobial peptide temporin B inhibits in vitro herpes simplex virus 1 infection","volume":"62","author":"Marcocci","year":"2018","journal-title":"Antimicrob Agents Chemother"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1136\/gutjnl-2015-310421","article-title":"Hepatitis C virus treatment in the real world: optimizing treatment and access to therapies","volume":"64","author":"Zoulim","year":"2015","journal-title":"Gut"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.1592\/phco.21.17.1352.34419","article-title":"Lopinavir-Ritonavir: a new protease inhibitor","volume":"21","author":"Mangum","year":"2001","journal-title":"Pharmacotherapy"},{"key":"B25","doi-asserted-by":"publisher","first-page":"106408","DOI":"10.1016\/j.bioorg.2023.106408","article-title":"Piperazine-derived small molecules as potential Flaviviridae NS3 protease inhibitors. In vitro antiviral activity evaluation against Zika and Dengue viruses","volume":"133","author":"Del Rosario Garc\u00eda-Lozano","year":"2023","journal-title":"Bioorganic Chem"},{"key":"B26","doi-asserted-by":"publisher","first-page":"84","DOI":"10.1016\/j.antiviral.2014.04.006","article-title":"Arbidol as a broad-spectrum antiviral: an update","volume":"107","author":"Blaising","year":"2014","journal-title":"Antiviral Res"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1021\/jm980263s","article-title":"Potent anti-HIV (type 1 and type 2) activity of polyoxometalates: structure-activity relationship and mechanism of action","volume":"43","author":"Witvrouw","year":"2000","journal-title":"J Med Chem"},{"key":"B28","doi-asserted-by":"publisher","first-page":"27670","DOI":"10.1038\/srep27670","article-title":"Microglia retard dengue virus-induced acute viral encephalitis","volume":"6","author":"Tsai","year":"2016","journal-title":"Sci Rep"},{"key":"B29","doi-asserted-by":"publisher","first-page":"28","DOI":"10.1016\/j.antiviral.2018.05.002","article-title":"Minocycline suppresses dengue virus replication by down-regulation of macrophage migration inhibitory factor-induced autophagy","volume":"155","author":"Lai","year":"2018","journal-title":"Antiviral Res"},{"key":"B30","doi-asserted-by":"publisher","DOI":"10.1128\/JVI.00062-06","article-title":"Murine model for dengue virus-induced lethal disease with increased vascular permeability","volume":"80","author":"Shresta","year":"2006","journal-title":"J Virol"},{"key":"B31","doi-asserted-by":"publisher","first-page":"81","DOI":"10.1080\/08923970701282726","article-title":"Activation of cytotoxic T lymphocyte responses and attenuation of tumor growth in vivo by Andrographis paniculata extract and andrographolide","volume":"29","author":"Sheeja","year":"2007","journal-title":"Immunopharmacol Immunotoxicol"},{"key":"B32","doi-asserted-by":"publisher","DOI":"10.1016\/j.intimp.2006.12.008","article-title":"Modulation of immune response in mice immunized with an inactivated Salmonella vaccine and gavaged with Andrographis paniculata extract or andrographolide","volume":"7","author":"Xu","year":"2007","journal-title":"Int Immunopharmacol"},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.1038\/375291a0","article-title":"The envelope glycoprotein from tick-borne encephalitis virus at 2 A resolution","volume":"375","author":"Rey","year":"1995","journal-title":"Nature"},{"key":"B34","doi-asserted-by":"publisher","DOI":"10.1016\/j.str.2004.06.019","article-title":"Conformational changes of the flavivirus E glycoprotein","volume":"12","author":"Zhang","year":"2004","journal-title":"Structure"},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.1128\/JVI.75.16.7769-7773.2001","article-title":"Monoclonal antibodies that bind to domain III of dengue virus E glycoprotein are the most efficient blockers of virus adsorption to Vero cells","volume":"75","author":"Crill","year":"2001","journal-title":"J Virol"},{"key":"B36","doi-asserted-by":"publisher","DOI":"10.1128\/JVI.78.1.378-388.2004","article-title":"An external loop region of domain III of dengue virus type 2 envelope protein is involved in serotype-specific binding to mosquito but not mammalian cells","volume":"78","author":"Hung","year":"2004","journal-title":"J Virol"},{"key":"B37","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/j.micinf.2006.09.009","article-title":"The envelope glycoprotein domain III of dengue virus serotypes 1 and 2 inhibit virus entry","volume":"9","author":"Chin","year":"2007","journal-title":"Microbes Infect"},{"key":"B38","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.02130-19","article-title":"Tryptophan trimers and tetramers inhibit dengue and zika virus replication by interfering with viral attachment processes","volume":"64","author":"Fikatas","year":"2020","journal-title":"Antimicrob Agents Chemother"},{"key":"B39","doi-asserted-by":"publisher","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":"Abdul Ahmad","year":"2017","journal-title":"Virol J"},{"key":"B40","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0074035","article-title":"Sulfated Escherichia coli K5 polysaccharide derivatives inhibit dengue virus infection of human microvascular endothelial cells by interacting with the viral envelope protein E domain III","volume":"8","author":"Vervaeke","year":"2013","journal-title":"PLoS One"}],"container-title":["Frontiers in Immunology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1663878\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,13]],"date-time":"2025-08-13T04:16:00Z","timestamp":1755058560000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1663878\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,13]]},"references-count":40,"alternative-id":["10.3389\/fimmu.2025.1663878"],"URL":"https:\/\/doi.org\/10.3389\/fimmu.2025.1663878","relation":{},"ISSN":["1664-3224"],"issn-type":[{"value":"1664-3224","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,8,13]]},"article-number":"1663878"}}