Malaria remains a critical global health challenge, worsened by the emergence of drug-resistant Plasmodium falciparum strains. Marine macroalgae offer an underexplored chemical space for novel treatments; however, previous efforts have primarily focused on organic solvent extractions, leaving the potential of sustainable, water-soluble preparations overlooked. This study evaluated the antimalarial activity and safety of aqueous extracts from pelagic Sargassum fluitans and Sargassum natans obtained from seasonal strandings along the Caribbean coast of Panama. Algal species were taxonomically identified, and aqueous extracts were prepared at 50°C. In vitro antiplasmodial activity was evaluated against the P. falciparum HB3 strain using the PicoGreen assay and thin blood smear microscopy, while cytotoxicity was assessed in Vero epithelial cells via the MTT assay. Both extracts demonstrated a significant concentration-dependent inhibition of parasite growth, reaching up to 97.35% for S. fluitans and 96.37% for S. natans at 10% v/v. Microscopic observation confirmed pronounced parasitic morphological alterations without compromising host erythrocyte integrity. Crucially, the extracts displayed low cytotoxicity in Vero cells, with negligible growth inhibition (0%-8%) at the lowest concentration tested (1.25% v/v). These findings suggest the presence of selective, water-soluble bioactive compounds, validating pelagic Sargassum biomass as a promising, accessible natural candidate for antimalarial drug discovery and sustainable biotechnological development.
Correoso et al. (Fri,) studied this question.