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 molecules 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. There are already more than 5800 secondary metabolites isolated and described from soft corals and these compounds have been frequently investigated in relation to their possible anticancer effect by testing their cytotoxic and antiproliferative activity against cancer cell lines. In the recently published review, we focused on Alcyoniidae, one of the largest octocoral families. From this research, 344 cytotoxic compounds were found, most of which have been discovered in the last 20 years as a demonstration that it is a research field that has exploded in recent times. 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 positive control in the various studies against specific cancer lines. The research project we have started 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. At this point we will define the possible mechanism of action of these compounds by study of the cellular target, of the mechanism that reduces cell viability, and of the biochemical pathways activate by these compounds. Finally, the ultimate aim is the identification of possible lead molecules for preclinical studies as a potential anticancer therapy. Soft corals may be still considered unexploited since the number of published works looks still small when compared to the vastness of biodiversity available. Furthermore, at the present time there is still no molecule deriving from these organisms which have reached the stages of pharmaceutical studies, unlike other organisms such as mollusks and sponges. So, this project and research group aims to be a turning point from this point of view.