Jundee RabablertJuree CharoenteeraboonSupathra TiewchareonNatthapol RabablertWeesuda MakittithornNantarat ChutipanyapornSupoth RajchakamVirach JunnuSutee YoksanSiriraj HospitalSilpakorn UniversityMahidol University2022-08-042022-08-042021-01-01Science, Engineering and Health Studies. Vol.15, (2021)263000872-s2.0-85128739203https://repository.li.mahidol.ac.th/handle/20.500.14594/79392Infection of Japanese encephalitis virus (JEV) generates brain swelling, namely Japanese encephalitis (JE) in human. This virus is spread by Culex spp. mosquitoes and causes 30% case-fatality rate in Asia and Western Pacific regions annually. No specific cure for the disease is available. Andrographis paniculate methanolic extract and its purified andrographolide exhibit anti-inflammatory and antiviral properties. Our study is focused to antiviral activity of A. paniculate extracts and its elements against JEV in vitro. Half-maximal cytotoxicity (CC50) and the maximum non-toxic doses (MNTD) of A. paniculata in SK-NMC and LLC-MK2 are less than the CC50 and MNTD of andrographolide in SK-NMC and LLC-MK2 at 3 days-post treatment by MTT colorimetric assay. Both A. paniculata and andrographolide have antiviral effect by simultaneous treatment more than pre-treatment and post-treatment at 3 days-post treatment by time-of-addition assay. Antiviral action of these agents interfered virus attachment and had virucidal activity. The results indicated that A. paniculata and andrographolide have the potential antiviral activity against JEV.Mahidol UniversityMultidisciplinaryArticleSCOPUS10.14456/10.14456/sehs.2021.25