Jellyfish blooms in the Mediterranean Sea: a potential source of functional novel food

The waste-to-resource approach promotes a paradigm shift in the management of jellyfishin coastal zones, where the sustainable exploitation of jellyfish blooms can be regardedas valuable source of benefits for a range of actors. In this framework, we studied threerhizostomeae jellyfish occurring in the Mediterranean Sea, the native Rhizostoma pulmoand Cotylorhiza tuberculata, and the non-indigenous species Cassiopea andromeda fortheir biomass, potentially useful as human food, and their content of bioactive compounds,with antioxidant, immunomodulatory, and anti-proliferative activities on cancer cells. R.pulmo received growing interest in western Countries where it's non-traditional food.Its organic matter, mainly composed by protein (mostly collagen), demonstrated to bevaluable source of bioactive peptides. We investigated the immunomodulatory potentialof R. pulmo protein hydrolysates, focusing on low-molecular weight peptide fractions,produced by enzymatic hydrolysis, and tested on U937-derived-macrophage cell culturesfor inflammation-related genes expression and cytokines quantification. Our analysesshowed that at non-cytotoxic concentrations, pepsin-hydrolysates significantly reducedexpression of the proinflammatory cytokine genes, IL-6 and TNF?, in a dose-response. Thezooxanthellatae C. tuberculata and C. andromeda are both characterized of high amount ofantioxidant compounds, partly due to the presence of endosymbiotic microalgae belongingto the family Symbiodiniaceae. Partially purified hydroalcoholic extracts of both jellyfishwere tested for their anti-proliferative activity and pro-apoptotic effects on human cancercells MCF7 and MB-MDA-231. These results suggest the biomass of outbreak-formingscyphozoans may represent a yet untapped resource, with potential use in food systems, inline with the goals of the blue-green growth economy.