Phaeophyta Extracts Exhibit Antiviral Activity against Feline Calicivirus

摘要

The objective of this study was to evaluate the antiviral activity of Phaeophyta extracts against feline calicivirus (FCV), used as a norovirus surrogate. A bioassay-guided cytotoxicity and virus infectivity assay revealed that methanolic extracts ofPhaeophyta possessed significant antiviral activity against FCV. Among them, Eisenia bicyclis extract exhibited the highest antiviral activity against FCV. The 50% effective concentration of the extract (EC_(50)) inhibiting FCV viral replication by 50% was 80 mug/ mL. The extract also showed the highest selectivity index, calculated from the ratio of the median cellular cytotoxicity concentration (CC_(50)) and EC_(50), indicating antiviral efficacy against FCV. In addition, significant interruption of FCV infection was observed by pretreatment of host Crandall-Reese feline kidney cells with the E. bicyclis extract (200 mug/mL) prior to virus infection, in a dose-dependent manner.