Microalgae-derived bioactive compounds - A natural ally in cancer immunotherapy

Microalgae, a diverse group of photosynthetic microorganisms, have emerged as a promising source of bioactive compounds with significant therapeutic potential. While extensively studied for their applications in nutrition, biofuels, and cosmetics, their role in immunomodulation, particularly in cancer therapy, remains underexplored. This review delves into the intricate relationship between the immune system and cancer, emphasizing the dual role of immune surveillance and immune escape in tumor progression. We highlight the unique potential of microalgae-derived metabolites such as phycocyanin from Spirulina platensis, sulfated polysaccharides from Porphyridium cruentum, fucoxanthin from Phaeodactylum tricornutum, and eicosapentaenoic acid (EPA) from Nannochloropsis spp. in enhancing anti-tumor immunity, modulating the tumor microenvironment, and overcoming immune suppression. These compounds have demonstrated preclinical efficacy in activating macrophages, promoting dendritic cell maturation, stimulating cytotoxic T lymphocytes, and enhancing natural killer (NK) cell activity. Unlike conventional immunotherapies, which often induce adverse effects and resistance, these compounds offer a dual action potential as they exhibit direct antitumor and immune activation properties. In addition to this, algal compounds are natural, potentially less toxic alternatives with multi-targeted immunomodulatory effects. This review stands apart from existing literature by comprehensively integrating insights into cancer immune-editing with the emerging role of microalgae in immune-based therapies. We suggest microalgae as a novel and sustainable approach for upcoming cancer immunotherapy research and chemical application by bridging the gap between marine biotechnology and oncology.