Arthrospira maxima extract prevents and cures Zika virus infection: In vitro analysis with VERO cells

Zika virus (ZIKV) infections have increased in recent years due to the lack of vaccines, specific antiviral treatments, and the difficulty controlling Aedes vectors. This infection leads to serious neurological disorders, such as microcephaly and Guillain-Barre <acute accent> syndrome. Although higher plants are widely recognized as sources of bioactive compounds, there is relatively limited knowledge of such molecules in algae and microalgae. In this article, we evaluated Arthrospira maxima extract for its antiviral properties against ZIKV. We performed in vitro experiments in African green monkey kidney (VERO) cells. A. maxima extract showed a strong dose -dependent inhibition of ZIKV replication. Based on the half -maximal effective concentration, microalgal extract (1.65 +/- 0.08 mu g/mL) was more effective than the reference drug ribavirin (3.4 +/- 0.8 mu g/mL). The cytotoxicity assay showed that the microalgal extract was safer than ribavirin: The selectivity index of the extract was 5 times higher than ribavirin. The microalgal extract also had a protective and preventive role in inhibiting ZIKV binding to VERO cells. After pretreating these cells with 2.5, 5, 10, or 20 mu g/mL of A. maxima extract for 2 h, the highest concentration had inhibited approximately 80 % viral adsorption. Finally, to investigate the direct impacts of A. maxima extract on the virus, we incubated ZIKV with 10 mu g/mL of extract before infection (-2 or - 1 h), during infection, and at 2-8 h post infection. There was unprecedented virucidal activity of A. maxima algal extract against ZIKV at all times. In conclusion, A. maxima extract counteracts viral exertion and exerts virucidal activity to prevent ZIKV infection.