Salicornia europaea L. as a Marine Bioactive Resource: Phytochemical Profile, Health Mechanisms, and Functional Applications in Precision Nutrition

Marine halophytes are gaining attention as a source of plant-derived bioactive compounds with potential applications across nutraceuticals, functional foods, and preventive nutrition. Among them, Salicornia europaea L. is a coastal succulent whose adaptation to hypersaline environments shapes a distinctive phytochemical profile of pharmacological interest. This narrative review integrates current evidence on the bioactive composition, mechanistic activities, and translational relevance of S. europaea and related Salicornia species. Their secondary metabolome includes flavonols, isorhamnetin glycosides, hydroxycinnamic acids, oleanane-type triterpene saponins, fermentable polysaccharides, carotenoids, and a mineral-rich ionic matrix. Reported activities span antioxidant, anti-inflammatory, vascular-protective, anti-adipogenic, glycaemic-modulating, antimicrobial, and microbiome-related effects, mediated through pathways involving NF-κB, PPAR-γ, endothelial nitric oxide signalling, and short-chain fatty acid production. Beyond its individual phytochemical components, the matrix as a whole may also support sodium-reduction strategies in food formulation, providing a complementary nutritional rationale for its incorporation as a functional ingredient. Despite a coherent body of mechanistic and preclinical findings, clinical evidence remains limited, particularly regarding long-term efficacy, dose standardisation, and bioavailability in humans. Future work should prioritise adequately powered intervention trials and standardised characterisation of marine halophyte bioactives to clarify their evidence-based role in functional food development and future precision nutrition applications.