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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.
- The mineral composition value of selected Azorean macroalgae with beneficial impact on human cardiovascular healthPublication . Paiva, Lisete S.; Lima, Elisabete M. C.; Neto, Ana I.; Batista, José A. B.In view of the current increasing demand of macroalgae for human consumption, due to its high nutritional and health-promoting value, this study determines the ash content and investigates the macromineral composition in seven selected Azorean macroalgae (the Chlorophyta Ulva compressa and Ulva rígida, the Ochrophyta Fucus spiralis and the Rhodophyta Gelidium microdon, Osmundea pinnatifida, Porphyra sp. and Pterocladiella capillacea) in order to estimate its potential impact on human cardiovascular health. The ash content of the studied macroalgae (dry weight basis) ranged from 10.70±2% (P. capillacea) to 38.61±0.7% (O. pinnatifida), which is higher than that of the most common vegetables. Thus, these macraalgae can contribute with essential microelements to human and animal nutrition. Regarding the macromineral composition, as compared to some common foods, the results revealed that F. spiralis, G. microdon, O. pinnatifida and P. capillacea presented a well-balanced Ca/Mg ratio (approx. 1:1) and consequently a potential positive effect on heartbeat regulation and myocardial infarction protection. The results also revealed that all studied macroalgae presented o low Na/K ratio (< 2) and, consequently, a potential human hypotensive effect. Thus, the results suggest that a regular consumption of the studied Azorean macroalgae, either directly or through food supplements, may have a protective effect on cardiovascular diseases, the world's most common cause of Human death.
- Seasonal Variability of the Biochemical Composition and Antioxidant Properties of Fucus spiralis at Two Azorean IslandsPublication . Paiva, Lisete S.; Lima, Elisabete; Neto, Ana I.; Baptista, JoséThis 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.
- Marine algal flora of Santa Maria Island, AzoresPublication . Neto, Ana I.; Parente, Manuela I.; Cacabelos, Eva; Costa, Ana C.; Botelho, Andrea Z.; Ballesteros, Enric; Monteiro, Sandra; Resendes, Roberto; Afonso, Pedro; Prestes, Afonso L.; Patarra, Rita F.; Álvaro, Nuno V.; Milla-Figueras, David; Neto, Raul M. A.; Azevedo, José M. N.; Moreu, IgnacioBACKGROUND: The algal flora of the Island of Santa Maria (eastern group of the Azores archipelago) has attracted interest of researchers on past occasions (Drouët 1866, Agardh 1870, Trelease 1897, Schmidt 1931, Ardré et al. 1974, Fralick and Hehre 1990, Neto et al. 1991, Morton and Britton 2000, Amen et al. 2005, Wallenstein and Neto 2006, Tittley et al. 2009, Wallenstein et al. 2009a, Wallenstein et al. 2010, Botelho et al. 2010, Torres et al. 2010, León-Cisneros et al. 2011, Martins et al. 2014, Micael et al. 2014, Rebelo et al. 2014, Ávila et al. 2015, Ávila et al. 2016, Machín-Sánchez et al. 2016, Uchman et al. 2016, Johnson et al. 2017, Parente et al. 2018). Nevertheless, the Island macroalgal flora is not well-known as published information reflects limited collections obtained in short-term visits by scientists. To overcome this, a thorough investigation, encompassing collections and presence data recording, was undertaken at both the littoral and sublittoral levels down to a depth of approximately 40 m, covering an area of approximately 64 km2. The resultant taxonomic records are listed in the present paper which also provides information on species ecology and occurrence around the Island, improving, thereby, the knowledge of the Azorean macroalgal flora at both local and regional scales. NEW INFORMATION: A total of 2329 specimens (including some taxa identified only to genus level) belonging to 261 taxa of macroalgae are registered, comprising 152 Rhodophyta, 43 Chlorophyta and 66 Ochrophyta (Phaeophyceae). Of these, 174 were identified to species level (102 Rhodophyta, 29 Chlorophyta and 43 Ochrophyta), encompassing 52 new records for the Island (30 Rhodophyta, 9 Chlorophyta and 13 Ochrophyta), 2 Macaronesian endemics (Laurencia viridis Gil-Rodríguez & Haroun; and Millerella tinerfensis (Seoane-Camba) S.M.Boo & J.M.Rico), 10 introduced (the Rhodophyta Acrothamnion preissii (Sonder) E.M.Wollaston, Antithamnion hubbsii E.Y.Dawson, Asparagopsis armata Harvey, Bonnemaisonia hamifera Hariot, Melanothamnus harveyi (Bailey) Díaz-Tapia & Maggs, Scinaia acuta M.J.Wynne and Symphyocladia marchantioides (Harvey) Falkenberg; the Chlorophyta Codium fragile subsp. fragile (Suringar) Hariot; and the Ochrophyta Hydroclathrus tilesii (Endlicher) Santiañez & M.J.Wynne, and Papenfussiella kuromo (Yendo) Inagaki) and 18 species of uncertain status (11 Rhodophyta, 3 Chlorophyta and 4 Ochrophyta).
- Nutritional and Functional Bioactivity Value of Selected Azorean Macroalgae: Ulva compressa , Ulva rigida , Gelidium microdon , and Pterocladiella capillaceaPublication . Paiva, Lisete S.; Lima, Elisabete; Neto, Ana I.; Marcone, Massimo; Baptista, JoséThis study presents information on the biochemical composition (dry weight basis), nutritional aspects, and angiotensin I-converting enzyme (ACE) inhibitory properties of selected macroalgae (Ulva compressa, Ulva rigida, Gelidium microdon, and Pterocladiella capillacea) from Azores. Moisture content was very high (83.2% to 90.0% of fresh weight). Total dietary fiber (33.7% to 41.0%) that presented a good balance of both soluble and insoluble fibers (15.5% to 19.2% and 18.2% to 21.8%, respectively) was the most abundant component in these macroalgae. Protein and ash (ranged from 15.7% to 23.4% and 10.7% to 20.7%, respectively) were the 2nd most abundant components in red and green macroalgae, respectively. Moderate soluble carbohydrate contents (14.5% to 19.8%) were found in all species. Lipid contents were low (1.0% to 4.3%), particularly in Ulva species (1.0% to 1.7%), but contained higher unsaturated fatty acids (FAs) (7.5% to 32.9% and 29.6% to 69.2% of total FA for monounsaturated fatty acid and polyunsaturated fatty acid groups, respectively) than saturated fatty acid (23.3% to 46.8% of total FA) contents. All the macroalgal proteins had high digestibility in vitro (82.2% to 89.4%, relatively to sodium caseinate), contained high quantity of essential amino acids (45.3% to 58.1% of total amino acids), but in different proportions, and were rich in aspartic and glutamic acids that together account for 17.2% to 36.2% of the total amino acids. These results suggested that regular consumption of the selected macroalgae may improve human health and revealed that they can be used for producing food supplements for human and animal nutrition and/or pharmaceuticals with potential effect on the regional economy. Furthermore, the ACE-inhibitory IC₅₀ values of 0.095 to 0.695 mg/mL for the <1 kDa protein hydrolysate fraction revealed a potential impact on hypertension disorder.
- Isolation and characterization of angiotensin I-converting enzyme (ACE) inhibitory peptides from Ulva rigida C. Agardh protein hydrolysatePublication . Paiva, Lisete S.; Lima, Elisabete; Neto, Ana I.; Baptista, JoséUlva 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 (<1 kDa, 1–3 kDa and >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.
- Guia de boas práticas para a apanha de algas nos Açores : O projeto ASPAZOR e o caso-estudo de Asparagopsis spp.Publication . Faria, João; Navas Noguera, Daniel; Prestes, Afonso L.; Cacabelos, Eva; Moreu, Ignacio; Martins, Gustavo M.; Pereira, Leonel; Neto, Ana I.As macroalgas, sendo organismos fotossintéticos, são uma fonte de oxigénio e um recetor de dióxido de carbono. Elas fornecem habitat, refugio de predadores e um ambiente seguro para a desova e viveiro de muitas espécies. São ricas em minerais e vitaminas, proteínas, aminoácidos essenciais, ácidos gordos e fibras alimentares, e por isso usadas na alimentação humana. […]. A colheita manual deve ser favorecida à colheita mecânica. […].
- Concise review of the species Pterocladiella capillacea (S.G. Gmelin) Santelices & HommersandPublication . Patarra, Rita F.; Iha, C.; Pereira, Leonel; Neto, Ana I.Pterocladiella capillacea is a well-known source of high quality bacteriological and pharmaceutical grade agar and agarose, being economically exploited in few countries. From current knowledge all raw material is collected from wild populations that are being overharvested. This resulted in a biomass shortage, and consequently the wholesale prices peaked in the last years and the future of this industry is uncertain. It is also recognized that, to date, there is not any known commercial cultivation of this species, mostly due to its slow growth. Ecologically, P. capillacea fronds act as nurseries and as a macroalgal habitat for several marine invertebrates and are an "hot spot" for opportunistic bacteria. In addition, algal fronds or parts of them are directly used as food by several marine grazers (e.g. turtles, fishes, gastropods and sea urchins). The present work compiles and updates the published information on P. capillacea biology, ecology and biotechnological potential and presents a concise review on the species distribution, morphology, anatomy, ecology, life history, productivity, effect of ecological determinants, wild and cultured stocks, harvesting and utilization.
- Pleistocene coralline algal buildups on a mid-ocean rocky shore : Insights into the MIS 5e record of the AzoresPublication . Rebelo, Ana C.; Rasser, Michael; Ramalho, Ricardo S.; Johnson, Markes E.; Melo, Carlos S.; Uchman, Alfred; Quartau, Rui; Berning, Björn; Neto, Ana I.; Mendes, Ana Rita Marques; Basso, Daniela; Ávila, Sérgio P.Located on the northern coast of Santa Maria Island (Azores Archipelago, central North Atlantic), the Lagoinhas section preserves a carbonate buildup correlated with Marine Isotope Substage (MIS) 5e, the warmest interval of the Last Interglacial. The buildup is formed mainly by crustose coralline algae (CCA) identified as Spongites sp., and some subordinate crusts of Lithophyllum sp. and Neogoniolithon sp., as well as cf. Titanoderma sp. Extant CCA buildups are not recorded in the archipelago. Herein, we describe in detail the morphological and taphonomical features of the Lagoinhas CCA buildup and interpret the environment in which it grew. Additionally, this buildup is compared with another of similar age, exposed in the Prainha-Praia do Calhau section on the island's opposite southern coast. The hydrodynamic regime appears to play a crucial role in the development of Azorean CCA buildups during the MIS 5e.
- The Azorean edible abalone Haliotis tuberculata, an alternative heavy metal-free marine resource?Publication . Torres, Paulo; Rodrigues, Armindo; Prestes, Afonso L.; Neto, Ana I.; Álvaro, Nuno V.; Martins, Gustavo M.Abalones are considered a delicacy and exploited for food worldwide. In many places, overfishing has led to the decimation of wild stocks and many are now reared in aquaculture systems. In the Azores, there is no tradition of eating abalones and Haliotis tuberculata stocks are still virtually untouched. However, as tourism in the islands grows and the stocks of other shellfish diminish, there is an increasing pressure to find alternative edible resources, leading to a rising interest in abalones. According to previous studies performed in the region, other edible species, including the local highly appreciated limpets and the giant barnacle, present high concentration levels of some heavy metals, which has been attributed to the volcanic origin of the islands. Here we analysed the metal content in the edible tissue of Haliotis tuberculata from São Miguel Island, Azores. The potential human health risks due to its consumption was assessed by estimating the average daily intake (EDI) and target hazard quotient (THQ) of metals. Similarly to other organisms in the Azores, abalones have higher than normal levels of some heavy metals, particularly cadmium, reflecting a local natural source that should be closely monitored from a public health point of view.