Antiviral Activity of Chlorophyll Extracts from sp., a Marine Microalga, Against Zika Virus Infection.

Recent advancements in the large-scale cultivation of sp. in Korea have enabled year-round production of this marine microalgae. This study explores the potential industrial applications of sp. biomass by investigating the antiviral properties of its extracts and primary components. The antiviral effects of sp. extracts were evaluated in Zika virus (ZIKV)-infected cells. Following extensive isolation and purification, the main compounds were characterized using liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) analyses. Their antiviral activities were confirmed using in vitro and in silico tests. sp. extracts reduced infectious viral particles and non-structural protein 1 messenger RNA levels in ZIKV-infected cells without inducing cytotoxicity. Additionally, they modulated the interferon-mediated immune system responses. sp. extracts are composed of four main chlorophylls: chlorophyll a, chlorin e-13-15-dimethyl-17-phytyl ester, hydroxychlorophyll a, and hydroxypheophytin a. Among them, chlorophyll a, chlorin e-13-15-dimethyl-17-phytyl ester, and hydroxypheophytin showed the antiviral activities in ZIKV-infected cells and molecular docking simulations predicted interactions between these chlorophylls and ZIKV. Our findings suggest that sp. chlorophyll extracts exert antiviral effects against ZIKV and could serve as potential therapeutic candidates against ZIKV infection.