Screening for polar lipids, antioxidant, and anti-inflammatory activities ofGloeothecesp. lipid extracts pursuing new phytochemicals from cyanobacteria

Cyanobacteria are photosynthetic organisms that produce a variety of molecules with beneficial properties for applications in fields such as food and feed, pharmaceuticals, and industrial chemicals. In particular, polar lipids from algae are gaining interest because they have been associated with bioactive properties and health benefits. Cyanobacteria have been little studied, particularly in the case ofGloeothecesp. whose polar lipidome is unknown. We have used a high-resolution liquid chromatography mass spectrometry-based approach to identify the polar lipidome ofGloeothecesp. and have also evaluated their antioxidant and anti-inflammatory potential. Results obtained allowed the identification of 162 lipid molecular species from glycolipids, betaine lipids, and phospholipid categories. These molecular species were esterified to fatty acids (FA) with C16 and C18 chain length and with a degree of unsaturation (DoU) ranging between 0 and 4. Some of the lipid species identified in the lipidome are recognized for their bioactive properties. Therefore, the antioxidant capacity of the polar lipid extracts was evaluated against superoxide (O-2(center dot-)) and nitric oxide ((NO)-N-center dot) radicals and the anti-inflammatory capacity using the COX-2 Enzyme Activity Assay Kit. The lipid extracts displayed antioxidant capacity toward O(2)(center dot-)and(center dot)NO radicals in a dose-dependent manner with IC(50)of 939.8 +/- 15.6 and 1033.7 +/- 17.9 mu g mL(-1), respectively. The extracts showed anti-inflammatory activity by the inhibition of the conversion of arachidonic acid to prostaglandin H2 (PGH2) via inhibition of COX-2, with the lowest concentration tested of 10 mu g mL(-1)inhibiting the production of PGH2 by about 58%. Overall, these results suggest that the extracts fromGloeothececould be a source of natural product, fostering increasing interest of cyanobacterial exploitation to produce food and metabolites with potential bioactive properties useful for nutraceutical, cosmetics, and medicinal applications.