Effectiveness of neutral electrolyzed water in inactivating HCoV-OC43 and SARS-CoV-2 on the surfaces of plastic and the medicinal plant Centella asiatica (L.) urban

Jukrapun Komaikul; Sasiporn Ruangdachsuwan; Sanjira Juntarapornchai; Duangnapa Wanlayaporn; Kunjimas Ketsuwan; Promsin Masrinoul; Suthee Yoksan; Pilaipan Puthavathana; Tharita Kitisripanya

doi:10.1016/j.heliyon.2022.e10294

Effectiveness of neutral electrolyzed water in inactivating HCoV-OC43 and SARS-CoV-2 on the surfaces of plastic and the medicinal plant Centella asiatica (L.) urban

Heliyon. 2022 Aug 20;8(8):e10294. doi: 10.1016/j.heliyon.2022.e10294. eCollection 2022 Aug.

Authors

Jukrapun Komaikul¹, Sasiporn Ruangdachsuwan¹, Sanjira Juntarapornchai¹, Duangnapa Wanlayaporn¹, Kunjimas Ketsuwan¹, Promsin Masrinoul¹, Suthee Yoksan¹, Pilaipan Puthavathana², Tharita Kitisripanya³

Affiliations

¹ Center for Vaccine Development, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand.
² Faculty of Medical Technology, Mahidol University, Thailand.
³ Department of Pharmacognosy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand.

Abstract

Concerns have been raised about viral contamination, including in crops due to the recent coronavirus disease 2019 pandemic. Limited evidence is available to support the use of sanitizing agents for human coronavirus-contaminated medicinal plants. Thus, we aimed to investigate the persistence of infectious human coronavirus OC43 (HCoV-OC43) as a SARS-CoV-2 surrogate in storage conditions and the capability of neutral electrolyzed water (NEW) to inactivate coronavirus, including in fresh plants such as C. asiatica. The levels of infectious HCoV-OC43 and the triterpenoid content of C. asiatica were quantified using a plaque assay and high-performance liquid chromatography, respectively. The results showed that the persistence of HCoV-OC43 on C. asiatica leaves is identical to that on inert polystyrene. When covered and kept at room temperature with high humidity (>90% RH), HCoV-OC43 can be stable on C. asiatica leaves for at least 24 h. NEW with 197 ppm of available chlorine concentration (ACC) was effective in inactivating both infectious HCoV-OC43 and SARS-CoV-2 in suspension (≥3.68 and ≥4.34 log reduction, respectively), and inactivated dried HCoV-OC43 on the surfaces of C. asiatica leaves (≥2.31 log reduction). Soaking C. asiatica leaves for 5 min in NEW with 205 ppm of ACC or water resulted in significantly higher asiaticoside levels (37.82 ± 0.29 and 35.32 ± 0.74 mg/g dry weight, respectively), compared to the unsoaked group (29.96 ± 0.78 mg/g dry weight). These findings suggest that although coronavirus-contaminated C. asiatica leaves can pose a risk of transmission, NEW could be an option for inactivation.

Keywords: Asiaticoside; Centella asiatica; Electrolyzed water; Human coronavirus OC43; Madecassoside; Medicinal plant; Neutral electrolyzed solution; Severe acute respiratory syndrome coronavirus 2; Surface sterilization; Virus sanitization.