Bioprospecting Phaeodactylum tricornutum as a source of lipids with anti-inflammatory and antioxidant potential

• Autor(a) principal: Batista, Joana Florência Gonçalves
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/36687
• topic: Microalgae; Phaeodactylum tricornutum; Omega-3 fatty acids; Polar lipids; Bioactivity; Anti-inflammatory activity; Antioxidant activity

Phaeodactylum tricornutum is a microalga with a high content of omega-3 polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA), and these omega-3 PUFA are mainly esterified on polar lipids, such as glycolipids, phospholipids, and betaine lipids. Omega-3 PUFA are well-known for their health benefits, namely in preventing inflammation-related non-communicable diseases. Nevertheless, the polar lipid content of this microalga remains poorly explored. Therefore, this work aimed (a) bioprospecting the extracts of P. tricornutum extract (provided by Allmicroalgae) obtained using ethanol ultrasound-probe assisted extraction and dichloromethane/methanol (2:1), and both glycolipid-enriched, phospholipid+betaine lipids-enriched fractions as source of add-value polar lipids with anti-inflammatory and antioxidant properties and (b) correlate the bioactive potential with the polar lipid composition, obtained using C18 LC-ESI-MS/MS lipidomic approach for a comprehensive identification and characterization of the polar lipid profile. Phaeodactylum tricornutum extracts and the polar lipids-enriched fractions revealed anti-inflammatory potential, through the inhibition of COX-2 enzymatic activity, in chemico, and by decreasing of the nitric oxide production, and the transcription of pro-inflammatory genes Il1b, Tnfα, Nos2 e Ptgs2, in vitro in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The extracts and enriched fractions also revealed antioxidant activity by scavenging both ABTS●+ e DPPH● radicals, in chemico. Thus, the results gathered with the polar lipids-enriched fractions demonstrated these lipids to play an important role in the anti-inflammatory and antioxidant activities displayed by the extracts. The characterisation of the lipid profile from both extracts and polar lipids-enriched fractions evidenced the high abundance of molecular species containing EPA and the presence of several lipid species previously reported with bioactivity. Thus, the results obtained in this work showed that P. tricornutum is a source of compounds with bioactive potential, including polar lipids with a high content of EPA, contributing to the valorisation of this microalga as potential source of raw material or ingredients. Additionally, EtOH+UAE extracts were shown to be a suitable alternative to obtain food-grade extracts enriched in polar lipids for potential use in several biotechnological sectors such as industry food, pharmaceutical and nutraceuticals.