The invasive alga Rugulopteryx okamurae has spread widely across European coasts, causing significant ecological and economic damage. In Portugal, mitigation strategies now include biomass valorisation within circular bioeconomy frameworks. While previous studies have identified phenolics, carotenoids, polyunsaturated fatty acids, proteins, and diterpenoids in R. okamurae , a comprehensive characterization of its lipid fraction is lacking. In this context, this study hypothesized that the lipid fraction of R. okamurae contains bioactive molecules that could support pharmaceutical, nutraceutical, or aquaculture applications. To explore this potential, lipids were extracted using the Bligh and Dyer method and evaluated for in vitro antioxidant and cytotoxic activities. Fatty acid profiling was performed by GC–MS, and untargeted lipidomics was conducted via UHPLC–HR–MS/MS. The extract showed marked antioxidant activity (FRAP: EC 50 = 1.16 mg mL⁻ 1 ) and strong cytotoxicity against tumoral cell lines (B16: EC 50 = 12.69 µg mL⁻ 1 ; HepG2: EC 50 = 23.04 µg mL⁻ 1 ; SH-SY5Y: EC 50 = 38.58 µg mL⁻ 1 ) and a non-tumoral line (HEK 293: EC₅₀ = 23.91 µg mL⁻ 1 ). Carotenoids (0.98 mg g⁻ 1 DW) and terpenoids (46.37 mg LE g⁻ 1 DW) may underlie these activities. The lipid fraction was rich in saturated (42.64%), monounsaturated (32.74%), and polyunsaturated (24.63%) fatty acids, mainly esterified into bioactive lipid classes. Bio-guided fractionation should now be pursued to isolate the cytotoxic components for antitumor evaluation, while enabling the safe exploitation of non-toxic lipid fractions in cosmeceutical, nutraceutical, or feed applications.
Trentin et al. (Fri,) studied this question.