Isolation, structural characterization and biological activities of polysaccharides from Chondrus crispus

Biomedical applications often exploit the biodegradability and biocompatibility of natural polysaccharides. In this study, polysaccharide extracts from Chondrus crispus (CC) were characterized using HPLC-SEC, FTIR and 1H NMR spectroscopy. The proliferative and migrative capacities of various extracts on RAW264.7 cells, along with their impact on nitric oxide (NO) production and phagocytosis, were assessed. Polysaccharide bioactivity was also explored using HDF and HaCaT cell lines. This study additionally investigated the anti-inflammatory effects of CC fractions on Caco-2 cells, examining their impact on cytokines (TNF-α, TGF-β1) and chemokine (MCP-1) expression. CC-derived polysaccharides effectively modulated inflammatory activity and improved scratch or exclusion wound healing. Hot (95 °C) extracted polysaccharides fraction CC-2B (λ and, κ-carrageenan) stimulated RAW264.7 cell proliferation, while cold (25 °C) extracted polysaccharides fraction CC-1A (0.5 μg/μL) inhibited cell proliferation at 24 h (69.7±4.8%, p<0.001), while exhibiting increased phagocytosis activity. Furthermore, RAW264.7 cells treated with hot-extracted fraction CC-2B showed a significant reduction in LPS-stimulated NO production (p<0.0001) over 24 h. HaCaT and HDF cell proliferation were stimulated when treated with fraction CC-2B (p<0.0001). Moreover, Caco-2 cells treated with all fractions displayed enhanced TGF-β1 expression and reduced TNF-α expression at 24 h, indicating the potential of these fractions for future medical applications. Polysaccharide cold-extracted fraction (CC-1A) exhibited highly effective anticoagulant properties. All polysaccharide fractions (0.13 μg/μL) appeared to be non-cytotoxic for Caco-2 cells during 24 h. CC-derived polysaccharides have potential applications in the medical (wound healing, gastrointestinal distress), food, cosmetic, and pharmaceutical industries.