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- Effect of food preparations on in vitro bioactivities and chemical components of fucus vesiculosusPublication . André, Rebeca; Guedes, Laura; Melo, Ricardo; Ascensão, Lia; Pacheco, Rita; Vaz, Pedro D.; Serralheiro, Maria LuisaFucus 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.
- Serum albumin modulates the bioactivity of rosmarinic acidPublication . Brito, Elsa; Silva, André; Fale, Pedro; Pacheco, Rita; Serralheiro, António; Haris, Parvez I.; Ascensão, Lia; Serralheiro, Maria LuisaRosmarinic acid (RA) is a phenolic compound with biological activity. The objective of the present study was to investigate whether this compound kept its biological activity in the presence of proteins. For this purpose, bovine serum albumin (BSA) was used as a model protein, and the capacity of the RA to inhibit acetylcholinesterase (AChE) and affect antioxidant activity was evaluated in the absence and presence of BSA. A mixture of phenolic compounds containing RA, obtained from a medicinal plant was added to this study. The AChE inhibitory activity of RA was reduced by *57% in the presence of BSA, while the antioxidant activity increased. These results lead to the investigation of the effect of RA on the BSA structure using Fourier transform infrared spectroscopy (FTIR). At 37 C and higher temperatures, RA caused a decrease in the temperature modifications onthe proteinstructure. Furthermore, FTIR and native-gel analysis revealed that protein aggregation/ precipitation, induced bytemperature, wasreduced in thepresence of RA. The novelty of the present work resides in thestudy of the enzyme inhibitory activity and antioxidant capacity of polyphenols, such as RA, in the presence of a protein. The findings highlight the need to consider the presence of proteins when assessing biological activities of polyphenols in vitro and that enzyme inhibitory activity may be decreased, while the antioxidant capacity remains or even increases.