1080Bioactive Polysaccharides from Halymenia durvillei: Structural Characterization and Functional Applications in Immunomodulation and Wound Healing

Amal D. Premarathna1,*, Michael Y. Roleda2,3, Alan T. Critchley4, and Rando Tuvikene1

1School of Natural Sciences and Health, Tallinn University, Narva mnt 29, 10120 Tallinn, Estonia.,
2Algal Ecophysiology Laboratory (AlgaE Lab), The Marine Science Institute, College of Science, University of the Philippines, Diliman 1101, Quezon City, Philippines.,
3Bolinao Marine Laboratory, UPMSI, Guiguiwanen, Luciente 1, Bolinao, Pangasinan, Philippines.,
4Verschuren Centre for Sustainability in Energy and Environment, Sydney, NS B1M 1A2, Canada.

Polysaccharides from algae have shown promising potential in various biomedical applications due to their biodegradability, biocompatibility, and non-toxic properties. In this study, we explored the bioactivity of polysaccharides extracted from Halymenia durvillei (HD, from Tomasa, Bolinao, Pangasinan) using hot (95 °C) and cold (25 °C) extraction methods. The polysaccharides were characterized by HPLC-SEC, FTIR, and 1H NMR spectroscopy. We assessed their effects on cell proliferation, migration, nitric oxide production, and phagocytosis using RAW264.7 cells, as well as their impact on inflammation and wound healing in HaCaT cells. The hot-extracted polysaccharide fraction, a highly sulfated galactan. (λ-carrageenan), significantly stimulated RAW264.7 cell proliferation and migration. In contrast, the cold-extracted fraction inhibited cell proliferation at higher concentrations (0.5 μg/μL etc.) but enhanced phagocytosis activity. Furthermore, RAW264.7 cells treated with the hot extract showed a significant reduction in LPS-stimulated nitric oxide (NO) synthesis (p<0.0001). In wound healing assays, HaCaT cells treated with HD polysaccharides exhibited significantly faster proliferation and migration (p<0.0001). Caco-2 cells exposed to the polysaccharide fractions showed elevated TGF-β1 expression and no detectable TNF-α expression at 24 h, indicating minimal inflammatory response and supporting their potential safety for future medical applications. Additionally, the anticoagulant activity of HD-derived polysaccharides was confirmed through an activated partial thromboplastin time (aPTT) test, showing a lower anticoagulant effect among the fractions tested. This study demonstrated that polysaccharides from Halymenia durvillei exhibited significant bioactivity, including promoting wound healing, enhancing immune response, and exhibiting anti-inflammatory properties. These findings suggest that HD-derived polysaccharides have potential applications in wound care, gastrointestinal health, and could be exploited in the food, cosmetic, and pharmaceutical industries.

Keywords: Carrageenan; NMR; FTIR; HPLC-SEC; Immunomodulatory; Pro-inflammatory cytokines; Anti-coagulant; wound healing.

Acknowledgment

This research was funded by Estonian Research Council grant PRG1808. The Philippines Commission on Higher Education- Leading the Advancement of Knowledge in Agriculture and Sciences (CHED-LAKAS) program through the project “Phytochemical Characterization of Macroalgae for Food and High Value Products (PhycoPRO)” funded the eucheumatoid sample collection, species barcoding, and cultivation.