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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.
- BioMol4Health_Biological chemistry: longevity in a cup of teaPublication . RESSAISSI, Asma; Fale, Pedro; Pacheco, Rita; Serralheiro, Maria LuisaInfusions have been studied on what concerns Alzheimer Disease, digestive process, diet cholesterol absorption and its biosynthesis inhibition. In the first two cases the inhibition of acetylcholinesterase (AChE) has been addressed. In the last two situations, an in vitro intestinal barrier has been simulated and the inhibition of the regulator enzyme (HMGR) in cholesterol biosysnthesis pathway has been studied. AChE has been the target of infusions inhibitory activity as its inhibition has been seen to improve cognition and global functioning1 in AD suffering people and to improve the gastrointestinal motility2. Given to lab animals the compounds presente in the infusions were able to reach the brain and inhibit the enzyme3. The effect of infusions on cholesterol bioavailability pointed out that some infusions were able to reduce cholesterol permeation4 and also to have some inhibitory activity5. Studies have indicated that phenolics are able to modify the cell proteome6. The infusions have also been shown to modify the amount of cholesterol transporter proteins in cell membrane and this maybe one of possible explanations for the reduction in cholesterol transport detected under the effect of infusions, on some people ando n simulated intestinal barrier.
- Melanin: production from cheese bacteria, chemical characterization, and biological activitiesPublication . Ferraz, Ana Rita; Pacheco, Rita; Vaz, Pedro D.; Pintado, C. M. B. S.; Ascensão, Lia; Serralheiro, Maria LuisaPigments are compounds of importance to several industries, for instance, the food industry, where they can be used as additives, color intensifiers, and antioxidants. As the current trend around the world is shifting to the use of eco-friendly commodities, demand for natural dyes is increasing. Melanins are pigments that are produced by several microorganisms. Pseudomonas putida ESACB 191, isolated from goat cheese rind, was described as a brown pigment producer. This strain produces a brown pigment via the synthetic Mueller-Hinton Broth. This brown compound was extracted, purified, analyzed by FTIR and mass spectrometry, and identified as eumelanin. The maximum productivity was 1.57 mg/L/h. The bioactivity of eumelanin was evaluated as the capacity for scavenging free radicals (antioxidant activity), EC50 74.0 & PLUSMN; 0.2 mu g/mL, and as an acetylcholinesterase inhibitor, with IC50 575 & PLUSMN; 4 mu g/mL. This bacterial eumelanin did not show cytotoxicity towards A375, HeLa Kyoto, HepG2, or Caco2 cell lines. The effect of melanin on cholesterol absorption and drug interaction was evaluated in order to understand the interaction of melanin present in the cheese rind when ingested by consumers. However, it had no effect either on cholesterol absorption through an intestinal simulated barrier formed by the Caco2 cell line or with the drug ezetimibe.
- Exploring the Hypocholesterolemic Potential of a Fucus vesiculosus Extract: Omic Insights into Molecular Mechanisms at the Intestinal LevelPublication . Rebeca, André; Pacheco, Rita; Santos, Hugo M.; Serralheiro, Maria LuisaHigh 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.
- Phenolic compounds from Actinidia deliciosa leaves: Caco-2 permeability, enzyme inhibitory activity and cell protein profile studiesPublication . Henriques, Joana; Fale, Pedro; Pacheco, Rita; Florêncio, Maria Helena; Serralheiro, Maria LuisaChemical compounds from leaves of fruit-producing trees, a waste from agricultural activity can be isolated and used as a source of natural bioactive chemicals. Boiling water was used as an extractant of bioactive compounds from Actinidia deliciosa leaves and co-extracted fibres were removed with ethanol precipitation. Rutin and quercitrin were the main flavonoids identified and quantified by RP-HPLC-DAD. No cytotoxicity was detected for any of the extracts towards Caco- 2 cell line. A permeation of approx. 14% of extract components through the cells monolayer was determined. The cell protein profile of Caco-2 cells was modified when in the presence of the fibre-free extract and transketolase was the protein over-expressed in the presence of polyphenols. Acetylcholinesterase inhibitory activity was also studied, IC50 of 0.56 mg/mL was obtained with the fibre-free extract. A. deliciosa leaves are a good source of phenolic compounds and, therefore, some advantage may be taken of this agricultural residue, due to their biological activity.
- Mechanism of action and the biological activities of Nigella sativa oil componentsPublication . Silva, André Filipe C.; Haris, Parvez I.; Serralheiro, Maria Luisa; Pacheco, RitaNigella sativa seeds oil is consumed because of its health benefits. Although the oil has been studied for its properties and composition, these effects are often associated with its major compound thymoquinone, and less has been reported about the other components' contributions to the pharmacological properties and mechanism of action. The present study aimed to evaluate the oil compounds' antioxidant and anti-tumour activities, and its effect on molecular targets associated with the claimed health effects. A wide a range of biochemical and biophysical techniques were used to understand the biological activities of the oil components. Compounds such as thymoquinone and volatile monoterpenes such as alpha-thujene, alpha-pynene, sabinene and 3-carene were identified by using GC-MS. Similar high antioxidant activities were obtained for the oil and its non-volatile (NV) fraction, with enzymes inhibition and cytotoxic activity against MCF-7 and A375 cells the oil showed a strong effect but not its NV fraction. Analysis of A375 cells' proteome in contact with the oil showed increased expression of proteins POTEF and HSP 90-b suggesting that the oil's antitumor effect was due to apoptosis and cellular stress. FT-IR studies in two model proteins in contact with the oil allowed oil compounds-protein interactions to be recognized and also showed that volatiles stabilized proteins. Therefore, not only thymoquinone but also the volatile monoterpenes were important for the diversity of properties, and therefore modifications in the chemical composition of the oil, as an outcome of storage or even food preparation, may affect its biological activity.
- Phenolic profile and biological activities of decoctions from Santolina impressa, a Portuguese endemic speciesPublication . Rodrigues, Ana M.; Fale, Pedro; Madeira, Paulo; Pacheco, Rita; Florêncio, Maria Helena; Ascensão, Lia; Serralheiro, Maria LuisaSantolina impressa Hoffmanns & Link is an aromatic Asteraceae species endemic to the southwest of Portugal. It is used in folk medicine as an herbal tea for gastrointestinal ailments and mouthwash antiseptic. The present study aimed to relate the chemical composition of decoctions from the aerial parts S. impressa with their antiacetylcholinesterase, antioxidant, antimicrobial and cytotoxic activities, in an attempt to explain the traditional use of this species. LC–MS/MS analysis identified chlorogenic acid and cynarin as the main components. Antimicrobial activity of the extracts was investigated against two cariogenic bacteria:- Streptococcus sobrinus and Streptococcus mutans, and these decoctions were not cytotoxic towards Caco-2 and HepG2 cell lines. Decoctions from capitula and stems/leaves showed high AChE inhibition, with IC50 values of 328 μg/mL and 579 μg/mL, respectively. The antioxidant activity measured using the DPPH radical scavenging assay showed an EC50 of 14.7 μg/mL and 12.9 μg/mL for capitula and stems/leaves extracts, respectively. The biological activities were kept constant after in vitro digestive process and the HPLC analysis did not indicate changes in the extract’s chemical composition. The results may explain the traditional use of S. impressa decoctions for digestive problems and as a mouthwash antiseptic.
- Action of euptox A from Ageratina adenophora juice on human cell lines: a top-down study using FTIR spectroscopy and protein profilingPublication . André, Rebeca; Catarro, Joana; Freitas, Dalia; Pacheco, Rita; Oliveira, Maria Conceição; Serralheiro, Maria Luisa; Fale, PedroEuptox A, from Ageratina adenophora juice, is a toxin associated with the plant's resistance to infections, invasiveness and traditional use in cancer treatment. We used FTIR spectroscopy and protein profiling of cell lines to study the impact of euptox A on human cells, to clarify its mechanism of action in a top-down approach. Euptox A was extracted from the juice of A. adenophora. Its stability in the gastrointestinal tract was evaluated, as the compound/juice is generally taken orally. Cytotoxicity was determined in HeLa, Caco-2 and MCF7 cells, and the mechanism of action analyzed by protein and metabolite profiles using electrophoresis and FTIR spectroscopy. Euptox A resisted gastrointestinal digestion and was the most cytotoxic component of the extract for all cell lines tests. Euptox A-treated HeLa cells showed changes in protein profile, especially on 40S ribosomal protein S8 (RP), generally associated with cancer cells. FTIR profiles of treated cells diverged in the same metabolites as cells treated with cisplatin, both in metabolite directed analysis and in multivariate analysis (principal component analysis). In conclusion, euptox A in this top-down study showed a cellular impact that suggests a strong potential against cancer, acting on cancer targeted cellular characteristics.
- Biological properties of phenolic compound extracts in selected Algerian honeys-The inhibition of acetylcholinesterase and alpha-glucosidase activitiesPublication . Zaidi, Hicham; Ouchemoukh, Salim; Amessis-Ouchemoukh, Nadia; DEBBACHE-BENAIDA, NADJET; Pacheco, Rita; Serralheiro, Maria Luisa; Araujo, Maria EduardaIntroduction: Honey is used in various cultures as a traditional medicine and folkloric treatment. The aim of this study was to determine the antioxidant and the anti-inflammatory activities of 31 Algerian honeys and acetylcholinesterase (AChE) and alpha-glucosidase inhibitory activities of phenolic compounds extracts of these honeys. Methods: The anti-inflammatory activity of honey was evaluated by the method of inhibition of BSA (Bovin Serum Albumin) heat-induced denaturation. The inhibition of AChE and alpha-glucosidase by the honey extracts was evaluated by in-vitro methods. Results: The highest percentage of inhibition (85.33%) of BSA denaturation was obtained with polyfloral honey (H27). Radical scavenging activity of honey samples against 1,1-diphenyl-2-picrilhydrazyl (DPPH), and 2,2'-azinobis(-3) -ethylbenzothiazoline-6-sulfonic acid (ABTS) varied from 4.41 to 83.93% and from 2.52 to 63.24%, respectively. AChE inhibitory activity is one target to prevent neurodegenerative damage in Alzheimer's disease. AChE inhibition recorded values from 20.69 to 76.04%. alpha-glucosidase inhibitors such as acarbose is preconized for the control of hyperglycemia and prevent diabetes damages. Honey extracts demonstrated a significant inhibitory effect on alpha-glucosidase activity. Moreover, the effect of Fabacece honey (H19) (IC50 = 52.20 mu g/mL) was found to be more potent than acarbose (IC50 = 204.27 mu g/mL). Correlations were observed between antioxidants and anti-inflammatory activities, AChE and alpha-glucosidase inhibitions with total phenolic compounds and flavonoids content in honey samples. Conclusion: This study showed that honey could be exploited as a potential antioxidant and anti-inflammatory agent within therapeutic medicine.
- Cork processing wastewaters components fractioned by ultrafiltration membranes–studies of antioxidant and antitumoral activityPublication . Gomes, Luís; Borges, Carlos; Serralheiro, Maria Luisa; Minhalma, Miguel; Pacheco, RitaBACKGROUND: Cork processing wastewater is an environmental problem due to its high content of organic matter, such as sugars and non-biodegradable compounds such as polyphenols (PPs), namely tannins. Membrane technology aimed at valorisation of the wastewaters components, concentrate stream, and simultaneously offer a pre-treatment of the wastewater, permeate stream. In this work, the identification of bioactive PPs was also envisaged. Several fractions of cork processing wastewaters were generated using two cellulose acetate ultrafiltration membranes of 3 kDa and 74 kDa for PPs isolation according to nature and molecular weights. The membranes were prepared by the phase inversion method and fractionation was made in concentration and diafiltration modes. The wastewater and the fractions were analyzed in terms of total organic carbon, total phenols, tannins and total polysaccharides content and the compounds present were identified by FTIR, LC–MS and quantified by HPLC-DAD. RESULTS: Compounds such as quinic, gallic, protocatechuic, brevifolin carboxylic and ellagic acids were identified as the major compounds in cork wastewater. The wastewater and the fractions were tested for antioxidant activity and for capacity to inhibit the proliferation of the growth of human breast carcinoma cell lines, MCF-7. The fractions revealed high antioxidant activity with EC 50 values ranging from 1.174 ± 0.069 to 1.943 ± 0.179 mg/mgDPPH. The fractions demonstrated to be efficient as cell proliferation inhibitors, with values of IC50 ranging from 0.20 ± 0.003 to 0.46 ± 0.02 mg mL-1. CONCLUSION: The process reported demonstrates that PPs compounds can be recovered from cork effluent and further reused as high-value bioactive compounds.
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