Microalgae are recognized as a relevant source of bioactive compounds. Among these bioactive products, lipids, mainly glycolipids, have been shown to present immunomodulatory properties with the potential to mitigate chronic inflammation. This study aimed to evaluate the anti-inflammatory effect of polar lipids isolated from Nannochloropsis oceanica and Chlorococcum amblystomatis. Three fractions enriched in (1) digalactosyldiacylglycerol (DGDG) and sulfoquinovosyldiacylglycerol (SQDG), (2) monogalactosyldiacylglycerol (MGDG), and (3) diacylglyceryl-trimethylhomoserine (DGTS) and phospholipids (PL) were obtained from the total lipid extracts (TE) of N. oceanica and C. amblystomatis, and their anti-inflammatory effect was assessed by analyzing their capacity to counteract nitric oxide (NO) production and transcription of pro-inflammatory genes Nos2, Ptgs2, Tnfa, and Il1b in lipopolysaccharide (LPS)-activated macrophages. For both microalgae, TE and Fractions 1 and 3 strongly inhibited NO production, although to different extents. A strong reduction in the LPS-induced transcription of Nos2, Ptgs2, Tnfa, and Il1b was observed for N. oceanica and C. amblystomatis lipids. The most active fractions were the DGTS-and-PL-enriched fraction from N. oceanica and the DGDG-and-SQDG-enriched fraction from C. amblystomatis. Our results reveal that microalgae lipids have strong anti-inflammatory capacity and may be explored as functional ingredients or nutraceuticals, offering a natural solution to tackle chronic inflammation-associated diseases.

Dunaliella salina is a green microalga extensively explored for β-carotene production, while knowledge of its lipid composition is still limited and poorly investigated. Among lipids, polar lipids have been highlighted as bioactive phytochemicals with health-promoting properties. This research aimed to provide an in-depth lipidome profiling of D. salina using liquid and gas chromatography coupled with mass spectrometry. The lipid content was 6.8%, including phospholipids, glycolipids, betaine lipids, sphingolipids, triglycerides, diglycerides, and pigments. Among the total esterified fatty acids, 13.6% were 18:3 omega-3 and 14.7% were 18:1 omega-9. The lipid extract of D. salina showed anti-inflammatory activity by inhibiting cyclooxygenase-2 activity at 100 µg/mL, dose-dependent antioxidant scavenging activity, and antidiabetic activity by inhibiting α-glucosidase activity at 25 and 125 µg/mL. In conclusion, the lipid extract of D. salina has the potential to be used as a functional food ingredient or in the nutraceutical and cosmeceutical industries.

The red alga Gelidium corneum is commonly harvested for agar extraction, producing significant biomass residue that remains underutilized. Gelidium corneum and its residue represent promising sources of high-value compounds, including lipid ingredients, encompassing omega-3 and omega-6 polyunsaturated fatty acids, with potential applications in foods and cosmetics. Algae lipids are quite diverse and complex, however the lipidome of G. corneum and its residue, along with their bioactive potential, remain largely unexplored. This study characterized the lipid signatures of G. corneum and its residue after agar extraction using reversed-phase liquid chromatography-tandem mass spectrometry (C18-RP-HPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) for esterified fatty acids (FAs) profiling. Despite low lipid content (<1% dry weight), G. corneum exhibited a higher glycolipid content, while the residue was richer in phospholipids and triacylglycerols. Nine FAs were identified, with FA 20:4 n-6 and FA 20:5 n-3 more abundant in G. corneum, and FA 18:1 n-9 and FA 18:2 n-6 in the residue, highlighting their nutritional and functional values. Their lipid profile comprised more than 400 lipid molecular species, following the trend of more glycolipids in G. corneum and phospholipids in the residue. Complex lipids with bioactive properties were identified in both matrices, expanding our knowledge of the lipid signature of this seaweed. Gelidium corneum lipids showed higher antioxidant scavenging activity and great anti-inflammatory potential by inhibiting cyclooxygenase-2 activity. Although neither matrix inhibited α-amylase, residue lipids effectively inhibited α-glucosidase activity. These findings emphasize G. corneum and its residue as sources of high-value lipids for sustainable biotechnological applications, including foods, nutraceuticals and cosmetics.