Untitled

Funder

Organizational Unit

Publications

Effect of food preparations on in vitro bioactivities and chemical components of fucus vesiculosus

Publication . André, Rebeca; Guedes, Laura; Melo, Ricardo; Ascensão, Lia; Pacheco, Rita; Vaz, Pedro D.; Serralheiro, Maria Luisa

Fucus vesiculosus is a brown macroalgae used in food and generally considered safe to be consumed, according to EU Directive (EC 258/97). The aim of this study is to analyze the e_ect of food preparation on F.vesiculosus of di_erent origins on what concerns its chemical constituents and final bioactivities. The aqueous extract of the seaweeds were obtained at di_erent temperatures, similar to food preparation and then purified by SPE. The compound identification was carried out by Liquid Chromatography High Resolution Mass Spectrometry (LC-HRMS/MS) and algae extracts microstructure were observed by Scanning Electron Microscopy (SEM). The activities were determined by using antioxidant activity, inhibition of acetylcholinesterase (AChE) and 3-hidroxi-3-methyl-glutaril-CoA (HMG-CoA) reductase (HMGR) together with Caco-2 cells line simulating the intestinal barrier. The activity of AChE and the HMGR were inhibited by the extracts giving IC50 values of 15.0 _ 0.1 _g/mL and 4.2 _ 0.1 _g/mL, respectively and 45% of the cholesterol permeation inhibition. The main compounds identified were phlorotannins and peptides derivatives. The mode of preparation significantly influenced the final bioactivities. Moreover, the in vitro results suggest that the preparation of F. vesiculosus as a soup could have hypercholesterolemia lowering effect.

2020-07-17Journal article

Open access

Molecular-level changes induced by hydroxycinnamic acid derivatives in HepG2 cell line: comparison with pravastatin

Publication . RESSAISSI, Asma; Pacheco, Rita; Serralheiro, Maria Luisa

Hydroxycinnamic acid derivatives are an important class of polyphenols found in fruits, vegetables, and medicinal plants and widely consumed in human diet. In the present work, alterations of HepG2 cells biochemical profile under the effect of four hydroxycinnamic acid derivatives (caffeic acid, m-coumaric acid, chlorogenic acid and rosmarinic acid) relatively to the effect of pravastatin, a drug often prescribed to inhibit HMG-CoA reductase enzyme, the regulator enzyme in the cholesterol biosynthesis pathway, were reported. The application of FTIR spectroscopy in combination with multivariate analysis by PCA showed a similarity between pravastatin and the four hydroxycinnamic acid derivatives in metabolite profile modification expressed by various changes in proteins region, the phosphate region which mainly corresponds to nucleic acids as well as in lipids regions. FTIR structural analysis in the amide I region, using resolution enhancement methods, such as second derivative and amide I deconvolution method, revealed significant decrease in alpha-helix/random coil and intermolecular beta-sheet decreased while intramolecular beta-sheet in treated cells showed an increase. It was also noticed that the intracellular cholesterol as well as esterified ingredients such as cholesterol esters in the cell membrane decreased. Moreover, principal component analysis (PCA) of the spectral data showed that the compounds and pravastatin were well separated from untreated cells showing a different mode of action on HepG2 treated cells for each compound.

2021-10-15Journal article

Restricted access

Edible seaweeds extracts: characterization and functional properties for health conditions

Publication . Coelho, Mariana; Duarte, Ana Patrícia; Pinto, Sofia; Botelho, Hugo M.; Reis, Catarina; Serralheiro, Maria Luisa; Pacheco, Rita

Seaweeds are popular foods due to claimed beneficial health effects, but for many there is a lack of scientific evidence. In this study, extracts of the edible seaweeds Arame, Nori, and Fucus are compared. Our approach intends to clarify similarities and differences in the health properties of these seaweeds, thus contributing to target potential applications for each. Additionally, although Arame and Fucus seaweeds are highly explored, information on Nori composition and bioactivities is scarce. The aqueous extracts of the seaweeds were obtained by decoction, then fractionated and characterized according to their composition and biological activity. It was recognized that fractioning the extracts led to bioactivity reduction, suggesting a loss of bioactive compounds synergies. The Arame extract showed the highest antioxidant activity and Nori exhibited the highest potential for acetylcholinesterase inhibition. The identification of the bioactive compounds in the extracts allowed to see that these contained a mixture of phloroglucinol polymers, and it was suggested that Nori's effect on acetylcholinesterase inhibition may be associated with a smaller sized phlorotannins capable of entering the enzyme active site. Overall, these results suggest a promising potential for the use of these seaweed extracts, mainly Arame and Nori, in health improvement and management of diseases, namely those associated to oxidative stress and neurodegeneration.

2023-03-10Journal article

Open access

Exploring the Hypocholesterolemic Potential of a Fucus vesiculosus Extract: Omic Insights into Molecular Mechanisms at the Intestinal Level

Publication . Rebeca, André; Pacheco, Rita; Santos, Hugo M.; Serralheiro, Maria Luisa

High blood cholesterol levels are a major risk factor for cardiovascular diseases. A purified aqueous extract of Fucus vesiculosus, rich in phlorotannins and peptides, has been described for its potential to inhibit cholesterol biosynthesis and intestinal absorption. In this work, the effect of this extract on intestinal cells' metabolites and proteins was analysed to gain a deeper understanding of its mode of action on lipids' metabolism, particularly concerning the absorption and transport of exogenous cholesterol. Caco-2 cells, differentiated into enterocytes, were exposed to the extract, and analysed by untargeted metabolomics and proteomics. The results of the metabolomic analysis showed statistically significant differences in glutathione content of cells exposed to the extract compared to control cells, along with an increased expression of fatty acid amides in exposed cells. A proteomic analysis showed an increased expression in cells exposed to the extract compared to control cells of FAB1 and NPC1, proteins known to be involved in lipid metabolism and transport. To the extent of our knowledge, this study is the first use of untargeted metabolomics and a proteomic analysis to investigate the effects of F. vesiculosus on differentiated Caco-2 cells, offering insights into the molecular mechanism of the extract’s compounds on intestinal cells.

2024-04-20Journal article

Open access