Unexplored Marine-Derived Microbial Metabolites as Next-Generation Antiparasitic Agents: Phytochemistry, Mechanistic Insights, and Translational Prospects

Background

Marine-derived microbial metabolites have emerged as an underexplored but exceptionally promising source of antiparasitic agents. Over the past two decades, intensive efforts in natural product discovery have revealed structurally unique compounds ranging from alkaloids, peptides, and polyketides to glycolipids and nucleoside analogues that exhibit potent activity against protozoan and helminthic parasites. In this review, we systematically evaluated the phytochemical diversity, pharmacological mechanisms, and toxicological considerations of these marine metabolites, with emphasis on compounds targeting Plasmodium, Leishmania, Trypanosoma, Toxoplasma, Entamoeba, and Schistosoma species.

Materials and Methods

This review systematically collated and critically analyzed published literature from PubMed, Scopus, and Web of Science focusing on marine microbial metabolites with antiparasitic activity. Data were integrated on phytochemical classes, biosynthetic origins, mechanisms of action, in vitro and in vivo efficacy, selectivity indices, toxicological evaluations, and translational feasibility.

Results

Diverse compounds including alkaloids (manzamine A, renieramycin A), nucleoside analogues (tubercidin), β-lactones (salinosporamide A), lipodepsipeptides (gallinamide A), and glycolipids (sulfoquinovosyl diacylglycerols) demonstrated potent activity against protozoan and helminthic parasites, with IC₅₀ values ranging from nanomolar to low micromolar. Mechanistic insights revealed proteasome inhibition, cysteine protease blockade, DNA synthesis interference, mitochondrial disruption, and membrane destabilization as key antiparasitic strategies. Preclinical studies indicated encouraging selectivity indices and tolerable host cytotoxicity for several scaffolds.

Conclusion

Marine microbial metabolites constitute a chemically diverse and pharmacologically valuable frontier for antiparasitic drug discovery. By integrating phytochemistry, pharmacology, and toxicology, this review highlights their translational potential and emphasizes future directions including biosynthetic engineering, SAR-guided analog design, and standardized in vivo validation to accelerate progression into clinical pipelines.