Therapeutic Potential of Neopyropia yezoensis: An Updated Review

<i>Neopyropia</i> (<i>N.</i>) <i>yezoensis</i> is a widely cultivated red alga in East Asia and valued worldwide for its rich bioactive constituents recognized for their health benefits, including polsaccharides, porphyrans, pigments, phenolic compounds, phycobiliproteins, polyunsaturated fatty acids, myosporin-like amino acids, and both synthetic and recombinant peptides. This review summarizes the current knowledge regarding the therapeutic potential of <i>N. yezoensis</i> extracts and their bioactive compounds. Based on in vitro, ex vitro, and in vivo experimental data (including those on <i>Drosophila melanogaster</i> larvae), this review comprehensively discusses its antioxidant, anti-inflammatory, neuroprotective, anti-atopic dermatitis, anti-colitis, anticancer, anti-aging, anti-atrophy, metabolic health-promoting effects, improving renal health, proliferating, anti-osteoarthritic, anti-allergic, antibacterial, and antivirus activities. The prebiotic effect of <i>N. yezoensis</i> porphyran through modulation of the gut microbiota was also investigated. Studies have indicated that protein hydrolysates and peptides derived from <i>N. yezoensis</i> with low molecular weights and aromatic and/or hydrophobic amino acids contribute significantly to these diverse bioactivities. Although <i>N. yezoensis</i> has shown promising bioactivity in preclinical models, validated clinical data in humans are currently lacking. Future research should prioritize the design and implementation of well-controlled human clinical trials to fully explore their therapeutic potential.