Antifilarial activity of marine sponge Haliclona oculata against experimental Brugia malayi infection

► Methanol extract of marine sponge (Haliclona oculata) was lethal to Brugia malayi. ► Chloroform fraction was most effective antifilarial both in vitro and in vivo. ► The activity was localized in a chromatographic fraction of chloroform fraction. ► Extracts showed lethality to both adult worm and mf in vitro and in vivo. ► The test samples were active in both primary and secondary in vivo screens.