Polysaccharides and flavonoids from seaweeds: A natural arsenal against drug-resistant malaria

Seaweed, a rich source of bioactive compounds, has garnered attention for its potential antimalarial properties, particularly through the action of polysaccharides and flavonoids. This review explores the mechanisms by which these compounds inhibit the growth of Plasmodium parasites, responsible for malaria. Sulfated polysaccharides, especially fucoidan derived from brown seaweeds, have demonstrated significant antimalarial activity by preventing the invasion of erythrocytes and suppressing parasite growth. Additionally, polysaccharides from various seaweed species, such as Sargassum and Gracilaria , have shown the capacity to enhance the immune response. Flavonoids, known for their antioxidant and anti-inflammatory properties, also exhibit antiplasmodial activity through mechanisms that may include interference with the parasite's life cycle. The review emphasizes the importance of extraction methods on the bioactivity of these compounds and discusses their potential as therapeutic agents against malaria. While promising, developing seaweed-derived antimalarial compounds faces challenges requiring further research to elucidate their mechanisms and optimize their efficacy. • Seaweed-derived polysaccharides like fucoidan inhibit Plasmodium by blocking red blood cell invasion and boosting immunity. • Flavonoids from marine algae disrupt Plasmodium metabolism and lifecycle, showing promise as low-toxicity antimalarials. • Seaweed compounds exhibit dual-stage activity, targeting both liver and blood stages of Plasmodium development. • Certain seaweed bioactives counteract drug-resistant malaria by modulating parasite enzymes and host pathways. • Extraction methods and compound composition influence the potency of seaweed metabolites in antimalarial therapy.