Bioprospecting of Maldivian soft coral: chemical ecology and cytotoxic activity of their secondary metabolites with a focus on the biochemical investigation of their effect against anticancer cell lines

Marine environments, and especially coral reefs, are the source of a wide range of bioactive natural products with structurally unique features. So far, more than 36,000 compounds from marine micro and macroorganisms have been isolated and more than 1000 new products are discovered every year. Since the 70s, from corals, as the target of study for drug discovery, many natural products with diverse and important biological activities of interest for human health have been isolated and characterized. In particular, soft corals have received specific attention as they produce a greater number of secondary metabolites since they do not possess a calcium carbonate exoskeleton, and consequently, they can survive in competitive environments thanks to their chemical defense strategy. These compounds isolated from soft corals have been frequently investigated concerning their possible anticancer effect. In our recently published review, we focused on Alcyoniidae, one of the largest octocoral families. From this research, 344 cytotoxic compounds were found, 70% of which have been discovered in the last 10 years as a demonstration that it is a research field that has exploded in recent times also thanks to rapid improvements in analytical technology, which provides access to the structural elucidation of unknown compounds even when present at trace concentration levels. Confirming the potential of this research area, 21 of these secondary metabolites displayed comparable and even higher cytotoxic activity than the chemotherapy drug used as a positive control in the various studies against specific cancer lines. Our research project will soon lead us to the identification and chemical characterization of new bioactive compounds extracted from Maldivian soft corals. Among these secondary metabolites we will define the most active ones based on the in vitro cytotoxicity test (MTT assay) on different cancer cell lines and will determine the possible mechanism of action by the study of the cellular target, of the mechanism that reduces cell viability, and of the biochemical pathways activated by these compounds. Finally, the ultimate aim is the identification