DCFQE - Artigos em Revistas Internacionais / Articles in International Journals
Permanent URI for this collection
Artigo ou um editorial publicado numa revista científica.
(Aceite; Publicado; Actualizado).
Pesquisar Copyright
Browse
Browsing DCFQE - Artigos em Revistas Internacionais / Articles in International Journals by Title
Now showing 1 - 10 of 46
Results Per Page
Sort Options
- Applications of sesquiterpene lactones : a review of some potential success casesPublication . Moujir, Laila M.; Callies, Oliver; Sousa, Pedro M. C.; Sharopov, Farukh; Seca, Ana M. L.Sesquiterpene lactones, a vast range of terpenoids isolated from Asteraceae species, exhibit a broad spectrum of biological effects and several of them are already commercially available, such as artemisinin. Here the most recent and impactful results of in vivo, preclinical and clinical studies involving a selection of ten sesquiterpene lactones (alantolactone, arglabin, costunolide, cynaropicrin, helenalin, inuviscolide, lactucin, parthenolide, thapsigargin and tomentosin) are presented and discussed, along with some of their derivatives. In the authors’ opinion, these compounds have been neglected compared to others, although they could be of great use in developing important new pharmaceutical products. The selected sesquiterpenes show promising anticancer and anti-inflammatory effects, acting on various targets. Moreover, they exhibit antifungal, anxiolytic, analgesic, and antitrypanosomal activities. Several studies discussed here clearly show the potential that some of them have in combination therapy, as sensitizing agents to facilitate and enhance the action of drugs in clinical use. The derivatives show greater pharmacological value since they have better pharmacokinetics, stability, potency, and/or selectivity. All these natural terpenoids and their derivatives exhibit properties that invite further research by the scientific community.
- Asparagopsis Genus : What We Really Know About Its Biological Activities and Chemical CompositionPublication . Ponte, José M. S.; Seca, Ana M. L.; Barreto, Maria do CarmoAlthough the genus Asparagopsis includes only two taxonomically accepted species, the published literature is unanimous about the invasive nature of this genus in different regions of the globe, and about the availability of large amounts of biomass for which it is important to find a commercial application. This review shows that extracts from Asparagospsis species have already been evaluated for antioxidant, antibacterial, antifungal, antiviral, antifouling, cytotoxic, antimethanogenic and enzyme-inhibitory activity. However, the tables presented herein show, with few exceptions, that the activity level displayed is generally low when compared with positive controls. Studies involving pure compounds being identified in Asparagopsis species are rare. The chemical compositions of most of the evaluated extracts are unknown. At best, the families of the compounds present are suggested. This review also shows that the volatile halogenated compounds, fatty acids and sterols that are biosynthesized by the Asparagopsis species are relatively well known. Many other non-volatile metabolites (halogen compounds, flavonoids, other phenolic compounds) seem to be produced by these species, but their chemical structures and properties haven’been investigated. This shows how much remains to be investigated regarding the secondary-metabolite composition of these species, suggesting further studies following more targeted methodologies.
- Bio-Guided Optimization of Cystoseira abies-marina Cosmeceuticals Extraction by Advanced TechnologiesPublication . Rosa, Gonçalo P.; Peixoto, Andreia F.; Barreto, Maria do Carmo; Seca, Ana M. L.; Pinto, Diana C. G. A.Cystoseira abies-marina (reclassified as Gongolaria abies-marina) is a brown seaweed species rich in meroterpenoids, presenting interesting antioxidant, antitumor, and anti-inflammatory activities. However, there is still a lot to uncover regarding the bioactive potential of this species, as evidenced by the lack of records of antiaging activities from Cystoseira abies-marina, making this macroalga an excellent candidate for studies of its cosmeceutical potential. Ultrasound-(UAE) and microwave-assisted extraction (MAE) are advanced sustainable technologies that are very efficient in enhancing bioactive compound extraction. Applying these extraction techniques to a new biological matrix often calls for optimizing the parameters toward the best extraction yield. Since Cystoseira abies-marina is a new matrix for both UAE and MAE techniques, the present work proposes the optimization of the extraction process, using a novel approach: instead of only focusing on increasing the yield, the goal of this work is to determine the parameters for UAE and MAE that lead to extracts with better antiaging activities. For this bio-guided approach, several Cystoseira abies-marina extracts were prepared by UAE and MAE under varying conditions of solvent, time, and algae/solvent ratios. Their antiaging activities were then determined, and all the results combined to unveil the conditions yielding extracts with higher cosmeceutical potential. Using statistical tools, it was found that, for UAE, the best conditions were ethyl acetate, 15 min, and a ratio of 1:4, which led to an extract with high yield, and causing the strong inhibition of tyrosinase and elastase. In turn, ethanol, 10 min, and a ratio of 1:4 were the best conditions for MAE, leading to the extract with the best antioxidant activity. The results show that the proposed bio-guided approach was effective in obtaining extracts with high cosmeceutical potential, unveiling the possibility of modulating an extract’s activity by changing the extraction method.
- Biochemical study of attached macroalgae from the Madeira Archipelago and beach-cast macroalgae from the Canary Islands: multivariate analysis to determine bioresource potentialPublication . Nunes, Nuno; Valente, Sofia; Ferraz, Sónia; Barreto, Maria do Carmo; Carvalho, Miguel A. A. Pinheiro deFifteen attached macroalgae from the Madeira Archipelago, comprising three green, three red and nine brown algal species, as well as two beach-cast macroalgal samples, collected along the north shore of Gran Canaria, were assessed for their biochemical properties. The analysis included the determination of total minerals, total carbohydrates, protein, lipids, chlorophyll a, total carotenoids, total phenolic content, fucoxanthin and phycobilins (allophycocyanin, phycocyanin and phycoerythrin). The results showed a high variability of biochemical composition, allowing for the targetting of specific bioresources for particular purposes, including functional foods. This work provides the foundation for a biorefinery strategy implementation plan, for which specific macroalgae may be targeted for valuable and beneficial compounds.
- 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.
- 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.
- Comparative Analysis of the Polyphenols, Caffeine, and Antioxidant Activities of Green Tea, White Tea, and Flowers from Azorean Camellia sinensis Varieties Affected by Different Harvested and Processing ConditionsPublication . Paiva, Lisete S.; Rego, Clara; Lima, Elisabete; Marcone, Massimo; Baptista, JoséThis study evaluates the polyphenol profiles as well as caffeine (dry weight basis), and antioxidant activities of green tea (GTs), white tea (WTs), and flowers (Fl) samples from Azorean Camellia sinensis varieties affected by different harvested and processing conditions. Epicatechins derivatives, determined by RP-HPLC/PDAD, presented higher values in GTs with respect to WTs, decreasing as follows: epigallocatechin-3-gallate > epicatechin-3-gallate epicatechin >> epigallocatechin, and higher values in summer and early autumn than in spring. This was also accompanied by an in consistent withering time pattern. Esterified catechins were higher in all samples (100.8–312.3 mg/g) with respect to non-esterified catechins (15.1–37.7 mg/g). Caffeine (6.2–27.7 mg/g) decreased as follows: WTs > GTs >> Fl, and inconsistent seasonal and withering patterns were observed among the WTs. Total phenolics (125.9–295.4 mg gallic acid equivalents/g dried extract) and total flavonoids (35.2–69.7 mg rutin equivalents/g dried extract), determined by Folin–Ciocalteu and colorimetric methodologies, were higher in GTs than in WTs and Fl. Concerning the antioxidant patterns, the free radical scavenging activity (FRSA) and ferric reducing antioxidant power (FRAP) presented EC50 values ranges from 3.6 to 17.3 µg/mL and 4.8 to 16.5 µg/mL, respectively, and ferrous ion-chelating (FIC) activity ranged from 47.1 to 82.8%, highlighting that FRSA was better than butylated hydroxytoluene (BHT). Tea leaves exhibited, in general, higher activities with respect to tea Fl, and the WT sample plucked in summer and withered for 23 h showed the highest FRAP and FIC activity. In conclusion, this study shows the characteristic variation of GTs, WTs, and Fl of two tea varieties and may support crop quality improvement and promote the valorization of tea Fl.
- Comparison of Apolipoprotein E polymorphism and other atherosclerotic risk factors in two Portuguese populations: the Influence of InsularityPublication . Lopes, Paula Alexandra; Gaspar, Gisela; Napoleão, Patrícia; Santos, Maria Cristina; Pavão, Maria Leonor; Viegas-Crespo, Ana MariaO principal objectivo deste estudo é o de pesquisar o efeito da insularidade nos polimorfismos da apolipoproteína (apo) E em indivíduos saudáveis do continente (Lisboa) e de Ponta Delgada (Ilha de S. Miguel, Arquipélago dos Açores). Adicionalmente, estudar a distribuição dos seus genótipos em doentes com aterosclerose da Ilha de S. Miguel. Em Lisboa, a distribuição dos genótipos da apo E foi a seguinte: e3/e3 > e3/e4 > e2/e3 > e4/e4, ao passo que em Ponta Delgada e independentemente da condição fisiológica foi: e3/e3 > e2/e3 > e3/e4. Distintas frequências genotípicas foram observadas entre homens e mulheres no grupo saudável de Ponta Delgada. O índice de massa corporal, hipertensão arterial e perfil lipídico, factores de risco associados ao processo aterosclerótico, revelaram algumas diferenças quando avaliados em função dos grupos alélicos. Neste estudo, os genótipos de risco da apo E, e2/e2 and e2/e4, não foram contabilizados. Curiosamente a proporção dos genótipos nas mulheres foi heterogénea nos 3 grupos estudados.
- Comparison of Azorean tea theanine to teas from other origins by HPLC/DAD/FD. Effect of fermentation, drying temperature, drying time and shoot maturityPublication . Baptista, José; Lima, Elisabete; Paiva, Lisete S.; Andrade, Ana L.; Alves, Maria G.The objectives of the present study were the determination of theanine (a specific amino acid of tea leaves with repercussion in human neuronal activity) by HPLC with o-phthaldialdehyde derivatisation prior analysis and comparison of its level in samples from different origins or from the same origin (Azores Islands) but with different processing conditions (fermentation, drying temperature and drying time) and shoot maturity. The results revealed a higher level of theanine in the Azorean green tea (3.10%), the only one produced in Europe, as compared with the Chinese, Japanese, Korean and Taiwan green teas that have an average theanine content of 1.52%, 1.34%, 0.89% and 2.76% of the dry weight (dw) of tea leaves, respectively. The fermentation for a longer period of time results in less theanine remaining (2.28% and 3.10% of dw for fermented and non-fermented tea, respectively). The drying temperature and time of the drying process have an inversely strong effect (4.45% and 5.65% of dw for dried at 55 °C during 8.50 h and at 40 °C during 7.10 h, respectively). The younger tea shoots have a higher theanine content than mature leaves (7.02% and 6.10% of dw, respectively). Our data suggested that a new type of Azorean theanine-rich tea may be produced by modifying the manufacturing processes of the younger tea shoots.