Seaweed Nutritional Value and Bioactive Properties: Insights from Ascophyllum nodosum, Palmaria palmata, and Chondrus crispus

This study investigates the nutritional composition and bioactive properties of <i>Palmaria palmata</i> (dulse), <i>Ascophyllum nodosum</i> (knotted wrack), and <i>Chondrus crispus</i> (Irish moss). Understanding the nutritional values of these seaweeds is very important due to their potential health benefits, especially their antioxidant properties and cytotoxic activities, which point to their ability to inhibit cancer cell proliferation. Comprehensive analyses were conducted to assess protein content, amino acid composition, mineral profile, fatty acids, polyphenols, total carotenoids, antioxidant activity, and cytotoxicity against cervical (HeLa), and colon (HCT-116) cell lines. <i>P. palmata</i> exhibited the highest protein content, while <i>C. crispus</i> was richest in calcium, iron, manganese, and zinc. Amino acid analysis revealed <i>C. crispus</i> as being particularly high in essential and non-essential amino acids, including alanine, glutamic acid, and glycine. <i>A. nodosum</i> and <i>C. crispus</i> were rich in polyunsaturated fatty acids (PUFAs), notably eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). <i>A. nodosum</i> showed the highest total carotenoid content. Polyphenol analysis highlighted the presence of compounds such as <i>p</i>-coumaric acid, gallic acid, and <i>p</i>-hydroxybenzoic acid across the species. Both the ethanolic and hexane <i>A. nodosum</i> extracts demonstrated the strongest antioxidant potential in DPPH^• and ABTS⁺ assays. The cytotoxicity evaluation revealed high anticancer activity of <i>A. nodosum</i> and <i>C. crispus</i> hexane extract against HeLa and HCT-116, though it employed cell cycle arrest and apoptosis. <i>A. nodosum</i> hexane extract exhibited moderate selective anticancer activity against HCT-116. These findings underscore the nutritional diversity and potential health benefits of these macroalgae (seaweed) species, suggesting their suitability as functional foods or supplements, offering diverse nutritional and therapeutic benefits.