Chrysin Suppresses DIV1 Replication and Alleviates Oxidative Stress in Litopenaeus vannamei Through DIV1 dUTPase ‐Associated Antiviral Activity

Decapod iridescent Virus 1 (DIV1) poses a major threat to crustacean aquaculture, yet effective antiviral agents remain limited. In this study, a biochemical screening assay was established using recombinant DIV1 dUTPase, a predicted viral enzyme selected as a biochemical screening target. Screening of 108 laboratory-preserved medicinal-plant crude extracts and subsequent evaluation of monomeric compounds identified chrysin as a candidate inhibitor. In the recombinant-enzyme assay, chrysin inhibited DIV1 dUTPase activity. In DIV1-infected Litopenaeus vannamei, chrysin treatment reduced viral loads and improved survival after challenge. Relative to the DIV1-infected control, chrysin treatment was also associated with higher SOD and CAT activities, GSH content and T-AOC. These findings support further evaluation of chrysin as an anti-DIV1 lead compound.