Antiviral Potential of Polysaccharides Extracted from Marine Macroalgae of the El Jadida Atlantic Coast (Morocco)

Herpes simplex virus type 1 (HSV-1) is a globally widespread pathogen, and its increasing prevalence, associated complications, and emerging drug resistance underscore the need for novel antiviral agents. In this study, polysaccharide fractions were extracted from seven marine algae species collected from the El Jadida Atlantic Coast, Morocco, using aqueous and Soxhlet extraction methods. The antiviral activity of these extracts against HSV-1, as well as their cytotoxicity, was evaluated. All tested extracts demonstrated notable antiviral activity. Among them, the polysaccharide from Chondracanthus acicularis exhibited the strongest effect (IC 50 = 17.78 ± 2.5 μg/mL), followed by the extract from Ellisolandia elongata (IC 50 = 18,12 ± 4,8 μg/mL). Importantly, none of the extracts showed cytotoxicity at the tested concentrations. These results highlight the potential of marine algal polysaccharides as antiviral agents and provide a basis for further studies on the chemical characterization and bioactivity of polysaccharides from marine macroalgae.