Bioactive Sulfated Polysaccharides from Green Algae Codium tomentosum Stackhouse, 1797: Structural Characterization and Therapeutic Potential

Overview & Synopsis

Marine seaweeds are recognized as a rich source of structurally diverse bioactive compounds, particularly sulfated polysaccharides with promising biomedical applications. In the present study, a sulfated polysaccharide Codium tomentosum fraction (PSCT) was extracted from the Moroccan green seaweed Codium tomentosum and subjected to comprehensive chemical, structural, and biological characterization. The extraction yield reached 22.01%, and the polysaccharide fraction was mainly composed of neutral sugars (66.84%), along with significant levels of sulfate groups (8.73%) and uronic acids (4.13%). Monosaccharide analysis revealed a predominance of galactose and arabinose, indicating a complex heteropolysaccharide structure. Spectroscopic and morphological analyses (FTIR, XRD, UV–Vis, and SEM–EDS) suggested predominantly amorphous characteristics and confirmed the sulfated profile of the extract. Biological evaluation demonstrated that PSCT exhibits multifunctional bioactivities. The extract showed notable antiviral activity against Herpes Simplex Virus 1 (HSV1), with an EC50 value of 12.22 ± 2.90 µg/mL and no detectable cytotoxicity (CC50 > 200.00 µg/mL). In addition, PSCT displayed strong antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans, with remarkably low MIC values ranging from 0.05 to 0.78 mg/mL. Furthermore, antioxidant assays revealed concentration-dependent activity, with up to 68% DPPH radical scavenging and an IC50 of 1.25 mg/mL, indicating a moderate antioxidant potential, along with notable reducing power in the FRAP assay. Overall, these findings highlight the potential of C. tomentosum-derived polysaccharides as multifunctional natural agents with antiviral, antimicrobial, and antioxidant properties, supporting their prospective application in pharmaceutical and biomedical fields.