Browsing by Author "Paiva, Lisete S."
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- Angiotensin I-converting enzyme (ACE) inhibitory activity of Fucus spiralis macroalgae and influence of the extracts storage temperature : A short reportPublication . Paiva, Lisete S.; Lima, Elisabete; Neto, Ana I.; Baptista, JoséRecently, increasing attention has been paid to the marine algae as a natural source of novel angiotensin-I converting enzyme (ACE) inhibitors, such as the phlorotannins that are the predominant polyphenols in brown algae. This study reports, for the first time, the ACE inhibition of methanol extract/fractions from Azorean brown algae Fucus spiralis (Fs) determined by HPLC-UV method, their total phenolic content (TPC) quantified as phloroglucinol equivalents (PE) and the effect of the Fs dry powder methanol extracts (Fs-DME) storage temperature on ACE inhibition. The results indicate that the ACE inhibition of Fs-DME decreased by 28.8% and 78.2% when stored during 15 days at −80 ◦C and −13 ◦C, respectively, as compared with the activity of Fs-DME at a refrigerated temperature of 6 ◦C and assayed immediately after extraction that showed a value of 80.1 ± 2.1%. This Fs-DME sample was fractionated by ultrafiltration membranes into three molecular weight ranges (3 kDa), presenting the fraction >3 kDa remarkably high ACE inhibition (88.8 ± 2.4%), TPC value (156.6 ± 1.4 mg PE/g of dry weight fraction) and yield. Furthermore, chromatographic and spectrophotometric analyses corroborate that phenolic compounds were present in Fs methanol extract/fractions, and also revealed that phloroglucinol occurs in Fs. The results seem to suggest that Azorean Fs can be a source of powerful ACE-inhibitory phlorotannins with potential impact on public health, particularly on hypertensive patients.
- Angiotensin I-Converting Enzyme (ACE) Inhibitory Activity, Antioxidant Properties, Phenolic Content and Amino Acid Profiles of Fucus spiralis L. Protein Hydrolysate FractionsPublication . Paiva, Lisete S.; Lima, Elisabete; Neto, Ana I.; Baptista, JoséFood 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.
- Antioxidant activity of macroalgae from the AzoresPublication . Paiva, Lisete S.; Patarra, Rita F.; Neto, Ana I.; Lima, Elisabete M. C.; Baptista, José A. B.Free radical scavenging activity (FRSA) was studied to determine the antioxidant activity of 8 common macroalgae species found in the Azores. Species under study were Porphyra sp., Osmundea pinnatifida, Pterocladiella capillacea, Sphaerococcus coronopifolius and Gelidium microdon, from Rhodophyta; Ulva compressa and Chaetomorpha pachynema, from Chlorophyta and Fucus spiralis from Phaeophyta.The antioxidant activity was evaluated in methanolic extract by a decolourisation solution test of 2,2-diphenyl-1-picrylhydrazyl (DPPH), used as a stable radical. The methanolic extracts were obtained from dried biomass by sequential extractions, attaining a final concentration of 2 mg.mL-1. The FRSA values ranged from 19.54% for S. coronopifolius to 60.05% for F. spiralis with standard deviation (SD) varying between 1.41% and 6.80%. Results indicated that the studied seaweeds are a very promising source of biological active compounds with antioxidante properties. The seaweeds were collected in the Azorean islands where seawater pollution levels are low. Consequently, these seaweeds represent a valuable and good source of antioxidante material with superior beneficial effects on human health.
- Azorean macroalgae as a food supplement: determination of proteins, fiber, and total of lipids and carbohydrates content.Publication . Paiva, Lisete S.; Lima, Elisabete M. C.; Baptista, José A. B.; Patarra, Rita F.; Neto, Ana I.This study evaluates the chemical composition (proteins, fiber, total lipids, total carbohydrates and ash) os selected macroalgae common at the Azorean shores with potencial nutricional value for human food suplement. The protein content ranged from 2.86% to 18.48% of dry weight (DW) for Padina pavonica and Codium adhaerens, respectively and fiber ranged from 31.02% to 69.10% of DW for Codium adhaerens and Cystoseira humilis, respectively. The total of lipids ranged from 1.55% to 5.20% of DW for Cystoseira humulis and Codium adhaerens, respectively, and the total of carbohydrates ranged from 7,61% to 16.78% for Padina pavonica and Codium adhaerens, respectively.
- Biotechnological applications of selected macroalgaePublication . Patarra, Rita F.; Paiva, Lisete S.; Leite, João; Lima, Elisabeth; Baptista, José A. B.; Neto, Ana I.
- Biotechnological conversion of Azorean bovine cheese whey for the production of bio-energyPublication . Rego, E.; Paiva, Lisete S.; Lima, Elisabete; Baptista, JoséThe world's economies, in most countries, are heavily dependent on fossil fuels. This reliance is becoming increasingly problematic taking into account that reserves are rapidly depleting, and no less important is the strong effect of fossil fuel emissions on the global carbon cycle. […].
- Bovine Milk Formula Based on Partial Hydrolysis of Caseins by Bromelain Enzyme : Better Digestibility and Angiotensin-Converting Enzyme-Inhibitory PropertiesPublication . Medeiros, Vera; Rainha, Nuno; Paiva, Lisete S.; Lima, Elisabete; Baptista, JoséA 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.
- Bromelain, a Group of Pineapple Proteolytic Complex Enzymes (Ananas comosus) and Their Possible Therapeutic and Clinical Effects. A SummaryPublication . Varilla, Carolina; Marcone, Massimo; Paiva, Lisete S.; Baptista, JoséBromelain 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.
- Characterization and quantification of total carbohydrates of selected macroalgae from S. Miguel litoral zone.Publication . Garrido, Elena R.; Paiva, Lisete S.; Baptista, José A. B.; Patarra, Rita F.; Neto, Ana I.
- Chemical composition and biological activities of Laurus essential oils from different Macaronesian IslandsPublication . Furtado, R.; Baptista, José; Lima, Elisabete; Paiva, Lisete S.; Barroso, J. G.; Rosa, José S.; Oliveira, LuísaEssential oils (EO) and eight pure components from the fresh leaves of Laurus novocanariensis (LN) from Madeira and of Laurus azorica (LA) from four Azorean Islands (S. Miguel-SMI, S. Maria-SMA, Pico-PIC and S. Jorge-SJO) were evaluated for fumigant and contact insecticidal effects on adult stage of Mediterranean fruit fly (medfly) and for inhibition of oviposition. The chemical composition of EO were analysed by GC/MS. Oxygen-containing mono- and sesquiterpenes (mainly 1,8-cineole) dominated in LN (50%), LA-SMA (88%) and LA-SMI (57%) and mono- and sesquiterpene hydrocarbons (mainly α-pinene) dominated in LA-PIC (61%) and LA-SJO (44%). Linalool and α-terpinyl acetate were also abundant in LA-SMA and trans-cinnamyl acetate in LA-SJO. These three components and all of the Laurus' EO showed high repulsive activity against medfly oviposition. In contact assays on medfly adults, a moderate degree of mortality was observed, being the most toxic samples, in decreasing order, trans-cinnamyl acetate > α-terpinyl acetate > LA-SMI ∼ LA-SMA > LA-SJO ∼ linalool. In fumigant assays, α-terpinyl acetate was the only compound that showed some toxicity on medfly adults. According to the obtained results, the Laurus EO seem promising to be used against medfly oviposition in integrated pest management strategy.