Antiviral effect of the seaweed Osmundaria obtusiloba against the Zika virus

Zika virus (ZIKV), a mosquito-borne member of the family Flaviviridae, is a human pathogen of global significance.Recently, ZIKV, has become a public health problem with increases in numbers of cases and a strong association between ZIKV outbreaks and the spread of cases of Guillain-Barré Syndrome and microcephaly.In this study, the extracts of the seaweed Osmundaria obtusiloba (O.obtusiloba) (native to the Brazilian coast) against ZIKV using Vero cells was evaluated.The seaweed extract tested inhibited ZIKV replication in a dose-dependent manner at low concentrations with EC 50 values of 1.82 μg/mL and a selective index (SI) of 288.Other results showed that this extract had significant virucidal effects.In addition, when the extract and Ribavirin were used concomitantly there was a significant synergistic effect.Our promising results suggest that extracts of O. obtusiloba are excellent candidates for further studies, and that marine algae are potentially important sources for the development of novel anti-ZIKV agents.