Macroalgas da costa Açoriana : fonte de antioxidantes naturais

A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues.[...]. Um estudo realizado em 2012 na Universidade dos Açores por Paiva e colaboradores teve como objetivo a determinação da atividade antioxidante de oito das macroalgas mais comuns do litoral dos Açores, tendo em conta os baixos níveis de poluição da agua do mar e o potencial da sua utilização para o consumo humano e/ou para a extração de novos compostos de elevado valor acrescentado para as industrias alimentares e farmacêutica. Este estudo revelou que algumas macroalgas apresentam elevada atividade antioxidante, nomeadamente Fucus spiralis e Gelidium microdon. Fucus spiralis, conhecida como “tremoço do mar”, e tradicionalmente consumida por populações de algumas ilhas sendo considerada um petisco regional, e Gelidium microdon, conhecida como “musgão”, foi durante muito tempo utilizada para exportação e posterior produção de agar. […].info:eu-repo/semantics/publishedVersio

Bromelain, a Group of Pineapple Proteolytic Complex Enzymes (Ananas comosus) and Their Possible Therapeutic and Clinical Effects. A Summary

Bromelain is a complex combination of multiple endopeptidases of thiol and other compounds derived from the pineapple fruit, stem and/or root. Fruit bromelain and stem bromelain are produced completely distinctly and comprise unique compounds of enzymes, and the descriptor "Bromelain" originally referred in actuality to stem bromelain. Due to the efficacy of oral administration in the body, as a safe phytotherapeutic medication, bromelain was commonly suited for patients due to lack of compromise in its peptidase efficacy and the absence of undesired side effects. Various in vivo and in vitro studies have shown that they are anti-edematous, anti-inflammatory, anti-cancerous, anti-thrombotic, fibrinolytic, and facilitate the death of apoptotic cells. The pharmacological properties of bromelain are in part, related to its arachidonate cascade modulation, inhibition of platelet aggregation, such as interference with malignant cell growth; anti-inflammatory action; fibrinolytic activity; skin debridement properties, and reduction of the severe effects of SARS-Cov-2. In this paper, we concentrated primarily on the potential of bromelain's important characteristics and meditative and therapeutic effects, along with the possible mechanism of action.info:eu-repo/semantics/publishedVersio

The surplus value of Azorean Camellia sinensis flowers as an important contributor affecting the nutraceutical benefits of green tea quality

Leaves from Camellia sinensis have been used to make teas for a long time, however, less attention has been paid to the flowers, which is a waste of an abundant resource that should be valorized. This study evaluates the representative tea metabolites content (dry weight basis) and antioxidant properties of Azorean C. sinensis flowers as compared to commercial Gorreana green tea (GorGT), the only one produced in Europe. We determined the variability of catechins, caffeine and L-theanine (THEA) by RP-HPLC/DAD and the confirmation of THEA by GC/MS. The antioxidants activities were determined by FRSA, FRAP and FIC methods. The total phenolics and total flavonoids were determined by the Folin-Ciocalteu and colorimetric methodologies. The results showed that flowers presented higher L-theanine (5.88 mg/g) but lower caffeine (4.10 mg/g) contents than GorGT (2.59 and 12.42 mg/g, respectively) and, therefore, a lower caffeine/theanine ratio (0.70 versus 4.80). The esterified catechins content (in percentage of total catechins) showed similar values for flowers (85.34%) and GorGT (86.45%), and the individual catechins decreased as follows: epigallocatechin-3-gallate > epicatechin-3-gallate ≫ gallocatecin-3-gallate. In antioxidant assays, GorGT presented better FRSA and FRAP but similar FIC as compared to flowers. Also, the total phenolics and flavonoids contents of dried extract presented higher values in GorGT: 321.56 mg gallic acid equivalents (GAE)/g and 47.17 mg rutin equivalents (RE)/g as compared to 141.94 mg GAE/g and 24.14 mg RE/g, respectively, for flowers. This study represents the first contribute to Azorean C. sinensis flowers valorization as a new-added material with nutraceutical benefits.info:eu-repo/semantics/publishedVersio

Screening for novel Angiotensin I - Converting Enzyme (ACE) inhibitory peptides from Azorean Macroalgae: Extraction, purification, characterization and evaluation of their antihypertensive activity

Jornadas "Ciência nos Açores – que futuro? Tema Ciências Naturais e Ambiente", Ponta Delgada, 7-8 de Junho de 2013.A descoberta de inibidores naturais da ECA como alternativa às drogas sintéticas tem-se tornado de suma importância na prevenção da hipertensão. O sistema Renina-Angiotensina desempenha um papel importante na regulação da pressão arterial, em particular na ativação da enzima conversora da angiotensina I (ECA), que converte esta na angiotensina II, um ente vasoconstritor, sendo portanto, a inibição da atividade da ECA importante na prevenção da hipertensão. O presente estudo visa contribuir para: (i)a investigação in vitro das propriedades inibitórias da ECA pelos péptidos obtidos das macroalgas mais abundantes dos Açores; (ii) a extração e purificação dos péptidos inibidores da ECA, bem como a determinação do seu perfil de aminoácidos; (iii) a valorização das macroalgas açorianas, com possível impacto na saúde públi - ca, tendo em conta o potencial dos derivados proteicos destas para a produção de alimentos funcionais e/ou produtos farmacêuticos que previnam a hipertensão; (iv) a comparação da atividade inibitória da ECA dos novos produtos biológicos marinhos (péptidos) com os anti-hipertensivos comer - ciais (sintéticos) prescritos aos pacientes e (v) a determinação da composição bioquímica das macroalgas selecionadas. A descoberta no final deste projeto, de constituintes novos das macroalgas dos Açores, particularmente os péptidos inibidores da ECA, terá um impacto para o desenvolvimento futuro da economia regional, e deverá representar um incentivo para a conservação de um ambiente marinho “limpo” e para a proteção da sua biodiversidade. Os resultados podem tam - bém contribuir para uma redução substancial dos fundos destinados aos pacientes hipertensos, especialmente os que são suportados pelo Serviço Regional de Saúde.ABSTRACT: There is a trend towards the searching for natural ACE inhibitors as alternatives to the synthetic drugs prescribed for hypertension. The rennin angiotensin system plays an important role in the regulation of blood pressure particularly with Angiotensin I-Converting Enzyme (ACE) that converts angiotensin I to angiotensin II, a potent vasoconstrictor. Therefore, the inhibition of ACE activity is a major focus in the prevention ofhypertension. The present study aims to contribute to: (i) the searching of the peptides from the most abundant Azorean macroalgae by the evaluation in vitro of their ACE inhibitory properties; (ii) the extraction, purification of the referred peptides and their amino acids profile determination; (iii) the valorization of Azorean macroalgae, with potential impact on public health taking into account the algae´s protein-derivative products for producing functional foods and/or pharmaceutical formulations that prevent hypertension; (iv) the comparison of the ACE inhibitory activity of the novel marine bio-products (peptides) with the prescribed synthetic commercial antihypertensive drugs and v) the determination of the biochemical composition of the selected Azorean macroalgae. At the end of this project, the discovery of such novel macroalgae’s components, particularly the ACE inhibitory peptides, will have the potential for future economic development which in turn can provide an incentive for the conservation of the biodiversity and for the maintenance of a clean environment ocean around the Azores Islands as a natural resource that must be preserved. The results may also contribute to the reduction of funds allocated for hypertensive patients, particularly the ones that are supported by the Regional Health Public Service

Angiotensin I-Converting Enzyme (ACE) Inhibitory Activity, Antioxidant Properties, Phenolic Content and Amino Acid Profiles of Fucus spiralis L. Protein Hydrolysate Fractions

Food protein-derived hydrolysates with multi-bioactivities such as antihypertensive and antioxidant properties have recently received special attention since both activities can play significant roles in preventing cardiovascular diseases. This study reports, for the first time, the angiotensin I-converting enzyme (ACE)-inhibition and antioxidant properties of ultrafiltrate fractions (UF) with different molecular weight ranges (<1, 1–3 and ≥3 kDa) obtained from Fucus spiralis protein hydrolysate (FSPH) digested with cellulase–bromelain. The amino acids profile, recovery yield, protein, peptide and total phenolic contents of these FSPH-UF, and the in vitro digestibility of F. spiralis crude protein were also investigated. FSPH-UF ≥3 kDa presented remarkably higher ACE-inhibition, yield, peptide and polyphenolic (phlorotannins) contents. Antioxidant analysis showed that FSPH-UF <1 kDa and ≥3 kDa exhibited significantly higher scavenging of 2,2-diphenyl-1-picrylhydrazyl radical and ferrous ion-chelating (FIC) activity. FSPH-UF ≥3 kDa had also notably higher ferric reducing antioxidant power (FRAP). Strong correlations were observed between ACE-inhibition and antioxidant activities (FIC and FRAP). The results suggest that ACE-inhibition and antioxidant properties of FSPH-UF may be due to the bioactive peptides and polyphenols released during the enzymatic hydrolysis. In conclusion, this study shows the potential use of defined size FSPH-UF for the prevention/treatment of hypertension and/or oxidative stress-related diseases.This study was financially supported by cE3c funding (Ref: UID/BIA/00329/2013). Lisete Paiva was supported by a doctoral grant (Ref: M3.1.2/F/014/2011) awarded by FRC (Fundo Regional da Ciência).info:eu-repo/semantics/publishedVersio

Isolation and characterization of angiotensin I-converting enzyme (ACE) inhibitory peptides from Ulva rigida C. Agardh protein hydrolysate

Ulva rigida protein was hydrolysed with pepsin plus bromelain after a screening of nine enzymes for optimal proteolysis. This hydrolysate, presenting ACE-inhibitory activity with an IC₅₀ value of 0.483 mg/mL, was fractionated by ultrafiltration membranes into three molecular weight ranges (3 kDa). The <1 kDa fraction that exhibited the highest activity (IC₅₀: 0.095 mg/mL) was purified using size-exclusion chromatography and reversed-phase high-performance liquid chromatography, yielding two active ACE-inhibitory purified peptides. Edman degradation revealed its amino acid sequences to be IP and AFL with IC₅₀ values of 0.020 and 0.023 mg/mL, respectively. Both peptides were synthesized to confirm the structure and to validate their ACE-inhibitory activities. Lineweaver–Burk plots suggest that IP acts as a non-competitive and AFL as a competitive ACE-inhibitors. Stability assays showed that both peptides are heat-stable and AFL is hydrolysed by intestinal mucosa peptidases to FL with IC₅₀ value of 0.004 mg/mL that acts as a non-competitive ACE-inhibitor. The results suggest that these peptides might have a potential use in the preparation of antihypertensive drugs or functional foods.This study was financially supported by funds from CIRN (Centro de Investigação de Recursos Naturais, University of the Azores) and by cE3c funding (Ref: UID/BIA/00329/2013). Lisete Paiva was supported by a doctoral grant (Ref: M3.1.2/F/014/2011) awarded by FRC (Fundo Regional da Ciência).info:eu-repo/semantics/publishedVersio

Propriedades bioativas de macroalgas comuns nos Açores

A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. Como e do conhecimento geral, a hipertensão e um dos maiores fatores de risco das doenças cardiovasculares e esta estimado que afeta cerca de 25% da população mundial. Existem varias drogas sintéticas no mercado utilizadas para o seu controlo e prevenção, mas todas apresentam vários efeitos secundários adversos, o que promove a necessidade de encontrar alternativas naturais que evitem ou reduzam estes efeitos secundários. Neste sentido, tem-se desenvolvido investigação na Universidade dos Açores, no Laboratório de Tecnologia Alimentar, sobre a composição nutricional e as atividades biológicas, nomeadamente antioxidantes e anti-hipertensivas, de macroalgas comuns nos Açores, com o objetivo de promover estas espécies como potencial fonte de compostos nutricionais e farmacêuticos importantes. Esta investigação, desenvolvida no âmbito de um projeto de Doutoramento financiado pelo Fundo Regional da Ciência e Tecnologia resultou em informação inovadora, já apresentada a comunidade científica nacional e internacional e já publicada em revistas científicas com revisão por pares. […].info:eu-repo/semantics/publishedVersio

Seasonal Variability of the Biochemical Composition and Antioxidant Properties of Fucus spiralis at Two Azorean Islands

This study evaluates, for the first time, the seasonal (winter and summer) and geographical (São Miguel–SMG and Santa Maria–SMA Islands) variability of Fucus spiralis (Fs) biochemical composition (dry weight basis) and antioxidant properties. Protein and carbohydrates presented higher values in Fs-SMGwinter, lipids, total dietary fiber, and energy value in Fs-SMAsummer, and ash and soluble dietary fiber/insoluble dietary fiber ratio in Fs-SMAwinter. The fatty acid (FA) profiles showed a lower SFA in Fs-SMGsummer, whereas MUFA and PUFA presented higher values in Fs-SMGsummer and Fs-SMGwinter, respectively. Excellent dietary ratios of n6/n3 PUFA and hypocholesterolemic/hypercholesterolemic FA were found, with lower values in Fs-SMAwinter and higher in Fs-SMGsummer, respectively. The highest total phenolics was found in Fs-SMAsummer acetone:water extract and total flavonoids showed the higher value in Fs-SMGwinter methanol extract. The best free radical-scavenging activity was observed in the Fs-SMAwinter methanol (EC50 = 0.045 mg/mL) and acetone: water (EC50 = 0.059 mg/mL) extracts. The ferric-reducing antioxidant power showed the best results in Fs-SMAwinter methanol extract (EC50 = 0.016 mg/mL) and Fs-SMAsummer acetone:water extract (EC50 = 0.017 mg/mL). The best ferrous ion-chelating activity was found in Fs-SMGwinter acetone:water extract. Overall, results revealed that F. spiralis nutritional and functional bioactivity values have geographical and seasonal variations and that its regular consumption may add benefits to human health.This study was financially supported by cE3c funding (Ref: UID/BIA/00329/2013). Lisete Paiva was supported by a doctoral grant (Ref: M3.1.2/F/014/2011) awarded by FRC (Fundo Regional da Ciência).info:eu-repo/semantics/publishedVersio

Bovine Milk Formula Based on Partial Hydrolysis of Caseins by Bromelain Enzyme : Better Digestibility and Angiotensin-Converting Enzyme-Inhibitory Properties

A new methodology was developed using bromelain as a proteolytic enzyme for the production of a partially hydrolyzed bovine milk formula, without changing the milk's organoleptic and nutritional properties. This study also revealed that the in vitro angiotensin-converting enzyme inhibition increased in the modified milk as compared with the control sample, showing the highest angiotensin-converting enzyme-inhibitory activity for fractions with molecular weights between 3 and 10 kg mol⁻¹. The Lineweaver-Burk plot revealed that the produced milk formula acted as a non-competitive inhibitor, as determined by high performance liquid chromatography.The authors are indebted to Uniao de Cooperativas Agricolas de Lacticinios e Produtores de Leite da Ilha de S. Miguel (UNILEITE), Arrifes, Ponta Delgada, Azores, for the milk samples. Financial support for graduate studies (Vera Medeiros) was provided by Azores University, UNILEITE, and the Government of Azores.info:eu-repo/semantics/publishedVersio

Variability of antioxidant properties, catechins, caffeine, L-theanine and other amino acids in different plant parts of Azorean Camellia sinensis

During Camellia sinensis tea processing, manufacturers usually remove the internodes, which are classified as waste. This study presents the first determination of plant part contribution, particularly internodes, to green tea quality, in order to find the best blend to maximize impact on human health. Catechins, caffeine and free amino acid (FAA) profiles were determined by RP-HPLC/DAD, total phenolics (TPC) and total flavonoids (TFC) by FolinCiocalteu and colorimetric methodologies, respectively, and antioxidant activities by free radical-scavenging activity (FRSA), ferric-reducing antioxidant power (FRAP) and ferrous ion-chelating (FIC) methods. Individual esterified catechins content decreased as follows: epicatechin-3-gallate > epigallocatechin-3-gallate ≫ gallocatecin-3-gallate, and epicatechin derivatives content ranged from 63.91 to 91.22% of total catechins. Caffeine content was higher in internodes. L-theanine, histidine, asparagine, phenylalanine, glutamic acid and methionine were the major FAAs, and internodes contained the highest amounts of L-theanine and histidine (17 and 13.73 mg/g of sample, respectively). TPC ranged from 201.51 to 265.48 mg gallic acid equivalents/g dry extract (DE) and TFC ranged from 23.84 to 72.02 mg rutin equivalents/g DE. Internodes presented the lowest FRSA (EC50 ¼ 6.10–13.50 μg/mL), FRAP (EC50 ¼ 5.70–11.40 μg/mL) and FIC activity (36.96–79.21%). Bud presented the highest FRSA and FRAP, and budþ1stþ2ndleaves þ internodes the highest FIC activity. The results revealed the potential contribution of the internodes to green tea quality and, consequently, to human health.This study was supported by PO Açores 2020 and by the Community Structural Funds FEDER and FSE for the 2014-2020 programming period, with implementation in the Azores Region, under the project "ACORES-01-0247-FEDER-000014".info:eu-repo/semantics/publishedVersio