{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T16:57:49Z","timestamp":1785430669290,"version":"3.56.0"},"reference-count":26,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T00:00:00Z","timestamp":1784505600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100017170","name":"Thailand Science Research and Innovation","doi-asserted-by":"publisher","award":["FRB690042\/0162"],"award-info":[{"award-number":["FRB690042\/0162"]}],"id":[{"id":"10.13039\/501100017170","id-type":"DOI","asserted-by":"publisher"}]},{"award":["FRB690042\/0162"],"award-info":[{"award-number":["FRB690042\/0162"]}],"id":[{"id":"https:\/\/ror.org\/000025p04","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002842","name":"Fundamental Fund 2026","doi-asserted-by":"publisher","award":["214482"],"award-info":[{"award-number":["214482"]}],"id":[{"id":"10.13039\/501100002842","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002842","name":"Chiang Mai University","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100002842","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/05m2fqn25","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Viral infections remain a major threat to poultry health and production worldwide, highlighting the need for novel antiviral strategies. This study evaluated the in vitro antiviral and virucidal activities of six Thai medicinal plant extracts against herpesvirus of turkey (HVT), a non-oncogenic avian herpesvirus widely used as a live vaccine vector and employed here as a preliminary in vitro screening model. Cytotoxicity, total phenolic content (TPC), and antioxidant capacity were assessed using the MTT, Folin\u2013Ciocalteu, DPPH, ABTS, and FRAP assays. Among the tested extracts, Caesalpinia sappan (CS) and Persicaria odorata (PO) exhibited the highest TPC and antioxidant activities and were selected for further antiviral evaluation. Both extracts significantly reduced HVT infectivity, infectious viral titers, and intracellular viral DNA levels in DF-1 cells (p &lt; 0.01). CS produced lower infectious viral titers (1.995 \u00d7 104 TCID50\/mL) than PO (8.24 \u00d7 104 TCID50\/mL); however, both extracts significantly reduced viral titers compared with the untreated control (1.78 \u00d7 106 TCID50\/mL). In the virucidal assay, pre-incubation of HVT with CS and PO significantly reduced infectious virus titers to 4.64 \u00d7 104 and 2.15 \u00d7 104 TCID50\/mL, respectively, compared with the untreated control (1.47 \u00d7 106 TCID50\/mL) (p &lt; 0.01). These findings identify C. sappan and P. odorata as promising sources of plant-derived compounds for future investigation as antiviral agents against avian herpesviruses. However, additional studies using virulent MDV-1, independent biological replicates, and in vivo models are required before their potential application to Marek\u2019s disease control can be established.<\/jats:p>","DOI":"10.3390\/ani16142241","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T06:09:09Z","timestamp":1784527749000},"page":"2241","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["In Vitro Screening of Thai Medicinal Plants Identifies Antiviral Candidates Against an Avian Herpesvirus"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2278-4793","authenticated-orcid":false,"given":"Nisachon","family":"Apinda","sequence":"first","affiliation":[{"name":"Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"},{"name":"Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6297-2890","authenticated-orcid":false,"given":"Chaiwat","family":"Arjin","sequence":"additional","affiliation":[{"name":"Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, 239, Huaykaew Road, Suthep, Muang, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nattanita","family":"Luekamlang","sequence":"additional","affiliation":[{"name":"Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nonpawit","family":"Sirirungruangsarn","sequence":"additional","affiliation":[{"name":"Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Phonlakit","family":"Saetiew","sequence":"additional","affiliation":[{"name":"Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0126-0758","authenticated-orcid":false,"given":"Anucha","family":"Muenthaisong","sequence":"additional","affiliation":[{"name":"Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"},{"name":"Office of Research Administration, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5311-2220","authenticated-orcid":false,"given":"Pongpisid","family":"Koonyosying","sequence":"additional","affiliation":[{"name":"Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"},{"name":"Faculty of Medicine, Nation University, Chiang Mai 50210, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-8747-2912","authenticated-orcid":false,"given":"Kanokwan","family":"Sangkakam","sequence":"additional","affiliation":[{"name":"Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Usanisa","family":"Konkhon","sequence":"additional","affiliation":[{"name":"Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Panuwat","family":"Yamsakul","sequence":"additional","affiliation":[{"name":"Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7648-2662","authenticated-orcid":false,"given":"Wasana","family":"Chaisri","sequence":"additional","affiliation":[{"name":"Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2329-8802","authenticated-orcid":false,"given":"Nattawooti","family":"Sthitmatee","sequence":"additional","affiliation":[{"name":"Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"},{"name":"Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1186\/s13567-016-0404-3","article-title":"Marek\u2019s disease in chickens: A review with focus on immunology","volume":"47","author":"Boodhoo","year":"2016","journal-title":"Vet. Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1080\/03079457.2011.646238","article-title":"The long view: 40 years of Marek\u2019s disease research and Avian Pathology","volume":"41","author":"Biggs","year":"2012","journal-title":"Avian Pathol."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Sun, G.R., Zhang, Y.P., Lv, H.C., Zhou, L.Y., Cui, H.Y., Gao, Y.L., Qi, X.L., Wang, Y.Q., Li, K., and Gao, L. (2017). A Chinese Variant Marek\u2019s Disease Virus Strain with Divergence between Virulence and Vaccine Resistance. Viruses, 9.","DOI":"10.3390\/v9040071"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Yang, F., Feng, C., Yao, Y., Qin, A., Shao, H., and Qian, K. (2020). Antiviral effect of baicalin on Marek\u2019s disease virus in CEF cells. BMC Vet. Res., 16.","DOI":"10.1186\/s12917-020-02595-x"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"4797","DOI":"10.5455\/OVJ.2025.v15.i10.2","article-title":"Marek\u2019s disease: A global challenge to poultry health and productivity","volume":"15","author":"Mulyati","year":"2025","journal-title":"Open Vet. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1016\/j.antiviral.2017.06.010","article-title":"Anti-herpes simplex virus type 1 activity of Houttuynoid A, a flavonoid from Houttuynia cordata Thunb","volume":"144","author":"Li","year":"2017","journal-title":"Antivir. Res."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Arjin, C., Pringproa, K., Hongsibsong, S., Ruksiriwanich, W., Seel-Audom, M., Mekchay, S., and Sringarm, K. (2020). In vitro screening antiviral activity of Thai medicinal plants against porcine reproductive and respiratory syndrome virus. BMC Vet. Res., 16.","DOI":"10.1186\/s12917-020-02320-8"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Vij, T., Anil, P.P., Shams, R., Dash, K.K., Kalsi, R., Pandey, V.K., Hars\u00e1nyi, E., Kov\u00e1cs, B., and Shaikh, A.M. (2023). A Comprehensive Review on Bioactive Compounds Found in Caesalpinia sappan. Molecules, 28.","DOI":"10.3390\/molecules28176247"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1016\/j.jep.2009.09.040","article-title":"Analgesic and anti-inflammatory effects of Cassia siamea Lam. stem bark extracts","volume":"127","author":"Banzouzi","year":"2010","journal-title":"J. Ethnopharmacol."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Akmal, M.N., Abdel Aziz, I., and Nur Azlina, M.F. (2023). Piper sarmentosum Roxb. methanolic extract prevents stress-induced gastric ulcer by modulating oxidative stress and inflammation. Front. Pharmacol., 13.","DOI":"10.3389\/fphar.2022.971443"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"49","DOI":"10.5344\/ajev.1977.28.1.49","article-title":"Total phenol analysis: Automation and comparison with manual methods","volume":"28","author":"Slinkard","year":"1977","journal-title":"Am. J. Enol. Vitic."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/j.foodchem.2007.05.065","article-title":"Antioxidative activity of Mungoong, an extract paste, from the cephalothorax of white shrimp (Litopenaeus vannamei)","volume":"106","author":"Binsan","year":"2008","journal-title":"Food Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/S0023-6438(95)80008-5","article-title":"Use of a free radical method to evaluate antioxidant activity","volume":"28","author":"Cuvelier","year":"1995","journal-title":"LWT-Food Sci. Technol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/S0076-6879(99)99005-5","article-title":"Ferric reducing\/antioxidant power assay: Direct measure of total antioxidant activity of biological fluids and modified version for simultaneous measurement of total antioxidant power and ascorbic acid concentration","volume":"299","author":"Benzie","year":"1999","journal-title":"Methods Enzymol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Apinda, N., Yao, Y., Zhang, Y., Muenthaisong, A., Sangkakam, K., Nambooppha, B., Rittipornlertrak, A., Koonyosying, P., Nair, V., and Sthitmatee, N. (2023). Efficiency of NHEJ-CRISPR\/Cas9 and Cre-LoxP engineered recombinant Turkey herpesvirus expressing Pasteurella multocida OmpH protein for fowl cholera prevention in ducks. Vaccines, 11.","DOI":"10.3390\/vaccines11091498"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/0022-1759(83)90303-4","article-title":"Rapid colorimetric assay for cellular growth and survival: Application to proliferation and cytotoxicity assays","volume":"65","author":"Mosmann","year":"1983","journal-title":"J. Immunol. Methods"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"769","DOI":"10.1099\/vir.0.81498-0","article-title":"Herpesvirus of turkey reconstituted from bacterial artificial chromosome clones induces protection against Marek\u2019s disease","volume":"87","author":"Baigent","year":"2006","journal-title":"J. Gen. Virol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.jviromet.2004.03.006","article-title":"Differential amplification and quantitation of Marek\u2019s disease viruses using real-time polymerase chain reaction","volume":"119","author":"Islam","year":"2004","journal-title":"J. Virol. Methods"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Co\u015fkun, N., Demir, R., Canbolat, A.A., Sar\u0131ta\u015f, S., Pekdemir, B., Bechelany, M., and Karav, S. (2025). Polyphenols as Antiviral Agents: Their Potential Against a Range of Virus Types. Nutrients, 17.","DOI":"10.3390\/nu17142325"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Arjin, C., Hongsibsong, S., Pringproa, K., Seel-Audom, M., Ruksiriwanich, W., Sutan, K., Sommano, S.R., and Sringarm, K. (2021). Effect of Ethanolic Caesalpinia sappan Fraction on In Vitro Antiviral Activity against Porcine Reproductive and Respiratory Syndrome Virus. Vet. Sci., 8.","DOI":"10.3390\/vetsci8060106"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"962","DOI":"10.1128\/AAC.00825-07","article-title":"Epigallocatechin Gallate Inactivates Clinical Isolates of Herpes Simplex Virus","volume":"52","author":"Xu","year":"2008","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"21595","DOI":"10.1038\/s41598-022-26206-x","article-title":"Brazilin from Caesalpinia sappan inhibits viral infection against PRRSV via CD163\u0394SRCR5 MARC-145 cells: An in silico and in vitro studies","volume":"12","author":"Arjin","year":"2022","journal-title":"Sci. Rep."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"012029","DOI":"10.1088\/1757-899X\/991\/1\/012029","article-title":"Phytochemical Screening, Antioxidant Activities, Total Phenolics and Flavonoids content of Leaves from Persicaria odorata Polygonaceae","volume":"991","author":"Nguyen","year":"2020","journal-title":"IOP Conf. Ser. Mater. Sci. Eng."},{"key":"ref_24","first-page":"175","article-title":"Investigation of twenty selected medicinal plants from Malaysia for anti-Chikungunya virus activity","volume":"19","author":"Chan","year":"2016","journal-title":"Int. Microbiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"111596","DOI":"10.1016\/j.biopha.2021.111596","article-title":"Antiviral activities of flavonoids","volume":"140","author":"Badshah","year":"2021","journal-title":"Biomed. Pharmacother."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"\u0160udomov\u00e1, M., and Hassan, S.T.S. (2023). Flavonoids with Anti-Herpes Simplex Virus Properties: Deciphering Their Mechanisms in Disrupting the Viral Life Cycle. Viruses, 15.","DOI":"10.3390\/v15122340"}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/14\/2241\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T04:11:00Z","timestamp":1784693460000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/14\/2241"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,20]]},"references-count":26,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["ani16142241"],"URL":"https:\/\/doi.org\/10.3390\/ani16142241","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,20]]}}}