Composition, in vitro antioxidant and angiotensin-converting enzyme inhibitory effects of lipids isolated from fifteen species of seaweeds

In this study, the lipid profile, in vitro antioxidant and angiotensin-converting enzyme (ACE) inhibitory effect of lipid extracts from 15 species of seaweed were evaluated. The lipid content varied from 0.7 ± 0.1 to 3.9 ± 0.3 g/100g dry weight. Brown seaweeds showed high levels of neutral lipids, whereas red seaweeds contained more polar lipids. Most of the sterols were in free form than the esterified form. The levels of polyunsaturated fatty acids (PUFAs) ranged from 8.1 ± 0.1% to 54.6 ± 6.9%, with α-linolenic acid (C18:3n-3) and eicosapentaenoic acid (C20:5n-3) being the primary ω-3 PUFAs, while arachidonic acid (C20:4n-6) was the main ω-6 PUFA. Lipid extracts from Polysiphonia platycarpa, Chondria cornuta and Sargassum boveanum showed the highest radical scavenging activity, whereas Padina gymnospora and Ulva lactuca had the highest iron chelating activity. Lipid extracts from B. pulmosa and P. gymnospora showed the highest protection against lipid oxidation and angiotensin-converting enzyme inhibition. These macroalgal lipids can be used as a potential source of bioactive compounds for food and pharma.