Percorrer por autor "Alves, Rita C."
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- Antioxidant properties of flowers and vegetative parts of wild Taraxacum sect. RuderaliaPublication . Dias, Maria Inês; Barros, Lillian; Sousa, Maria João; Alves, Rita C.; Oliveira, Beatriz; Ferreira, Isabel C.F.R.The species of the genus Taraxacum are known as dendalion (due to the shape of the leaves) and are commonly found in the Northern Hemisphere, in inhabiting fields and roadsides with warmer temperatures. Dendalion infusion and decoction are used in traditional medicine to treat kidney disease, dyspepsia, arthritic and rheumatic complaints, skin problems like eczema and even diabetes mellitus. Besides the pharmaceutical uses, the whole plant is included in many food products [1]. One of the most commonly consumed species is T. officinale; however, traditional collectors have sometimes difficulties in distinguish different Taraxacum species. In the present study, two samples of wild Taraxacum sect. Rudera/ia collected in Bragan9a, flowers and vegetative parts, were studied for their antioxidant activity. Free radicals (DPPH- 2,2-diphenyl-1- picrylhydrazyl) scavenging activity, reducing power and lipid peroxidation inhibition were evaluated on the methanolic extract, infusion and decoction of dandelion samples. The results of the antioxidant activity of the flowers and vegetative parts were very similar. Decoctions of both samples showed the highest DPPH scavenging activity (EC50= 0.42 and 0.12 mg/ml for flowers and vegetative parts, respectively). The decoction of vegetative parts also showed the highest reducing power (EC50= 0.16 mg/ml). The decoction of flowers and the infusion of vegetative parts showed very similar results for 13-carotene bleaching inhibition (EC50= 0.40 and 0.46 mg/ml, respectively) .The methanolic extract of vegetative parts showed the highest activity in TSARS (thiobarbituric acid reactive substances) assay (EC50= 0.13 mg/ml), although the infusion revealed also a low EC50 value for the same assay (0.16 mg/ml). As far as we know, there are no previously studies on the comparison of the antioxidant activity of different extracts and parts of this species of dendalion. More studies will be conducted to evaluate the activity against human tumour cell lines and to characterize the bioactive compounds present in the different extracts.
- Aplicação de um método cromatográfico para a determinação de vitamina E em Prunus dulcisPublication . Barreira, João C.M.; Alves, Rita C.; Casal, Susana; Ferreira, Isabel C.F.R.; Oliveira, Beatriz; Pereira, J.A.
- Caracterização química de amostras silvestres e comerciais de Achillea millefolium L.Publication . Dias, Maria Inês; Barros, Lillian; Carvalho, Ana Maria; Alves, Rita C.; Oliveira, Beatriz; Ferreira, Isabel C.F.R.As plantas medicinais têm vindo a ser usadas desde tempos ancestrais e surgem hoje em dia como uma alternativa aos produtos sintéticos, devido à sua riqueza em compostos bioativos [1]. Achillea millefolium L. pertence à família das Asteraceae e é vulgarmente conhecida como milefólio ou milfolhada, sendo muito comum em prados, caminhos, campos de cultivo e quintais. Disseminada por toda a Europa, as suas infusões, decocções e extractos alcoólicos são muito utilizados no tratamento de problemas digestivos, diabetes e doenças hepatobiliares, mostrando também propriedades antitumorais, antimicrobianas, anti-inflamatórias e antioxidantes [2, 3]. No presente trabalho, foram caracterizadas amostras comerciais e silvestres de A. millefolium em termos de composição nutricional e perfil em açúcares livres, ácidos orgânicos, ácidos gordos e tocoferóis, determinados por técnicas cromatográficas acopladas a diferentes detectores (HPLC-RI, HPLC-PDA, GC-FID e HPLC-fluorescência, respetivamente). Os hidratos de carbono, seguidos das proteínas, foram os macronutrientes maioritários em ambas as amostras. A amostra comercial mostrou um teor mais elevado de gordura (ácidos gordos saturados, especialmente ácido palmítico, C16:0), proteínas, cinzas, valor energético e açúcares totais (incluindo frutose, sacarose e trealose). A amostra silvestre revelou maior conteúdo em hidratos de carbono; também revelou a presença de rafinose (não tendo sido detetada na amostra comercial), ácidos gordos polinsaturados (maioritariamente ácido linoleico, C18:2n-6) e ácidos orgânicos (incluindo os ácidos málico, oxálico e quínico). Relativamente aos tocoferóis, ambas as amostras revelaram um perfil muito semelhante, apesar da amostra silvestre ter mostrado uma maior concentração em tocoferóis totais; o γ- tocoferol foi a isoforma mais abundante, enquanto o δ-tocoferol não foi detetado nas amostras estudadas. Os resultados obtidos são uma prova clara que as plantas usadas na medicina tradicional podem ter aplicabilidade não só em produtos caseiros mas também na indústria alimentar e farmacêutica como fonte de compostos bioativos.
- Caracterização química de amostras silvestres e comerciais de Achillea millefolium L.Publication . Dias, Maria Inês; Barros, Lillian; Carvalho, Ana Maria; Alves, Rita C.; Oliveira, Beatriz; Ferreira, Isabel C.F.R.As plantas medicinais têm vindo a ser usadas desde tempos ancestrais e surgem hoje em dia como uma alternativa aos produtos sintéticos, devido à sua riqueza em compostos bioativos. Achillea millefolium L. pertence à família das Asteraceae e é vulgarmente conhecida como milefólio ou milfolhada, sendo muito comum em prados, caminhos, campos de cultivo e quintais. No presente trabalho, foram caracterizadas amostras comerciais e silvestres de A. millefolium em termos de composição nutricional e perfil em açúcares livres, ácidos orgânicos, ácidos gordos e tocoferóis, determinados por técnicas cromatográficas acopladas a diferentes detectores (HPLC -RI, HPLC -PDA, GC -FID e HPLC -fluorescência, respetivamente). Os hidratos de carbono, seguidos das proteínas, foram os macronutrientes maioritários em ambas as amostras. A amostra comercial mostrou um teor mais elevado de gordura, proteínas, cinzas, valor energético e açúcares totais A amostra silvestre revelou maior conteúdo em hidratos de carbono; também revelou a presença de rafinose, ácidos gordos polinsaturados e ácidos orgânicos. Relativamente aos tocoferóis, ambas as amostras revelaram um perfil muito semelhante, apesar da amostra silvestre ter mostrado uma maior concentração em tocoferóis totais. Os resultados obtidos são uma prova clara que as plantas usadas na medicina tradicional podem ter aplicabilidade não só em produtos caseiros mas também na indústria alimentar e farmacêutica como fonte de compostos bioativos.
- Chemical composition of wild and commercial Achillea millefolium L. and bioactivity of the methanolic extract, infusion and decoctionPublication . Dias, Maria Inês; Barros, Lillian; Dueñas, Montserrat; Pereira, Eliana; Carvalho, Ana Maria; Alves, Rita C.; Oliveira, Beatriz; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.Medicinal plants used in folk medicine are being increasingly studied and used on pharmaceutical, food and nutraceutical fields. Herein, wild and commercial samples of Achillea millefolium L. (yarrow) were chemically characterized with respect to their macronutrients, free sugars, organic acids, fatty acids and tocopherols. Furthermore, in vitro antioxidant properties (free radicals scavenging activity, reducing power and lipid peroxidation inhibition) and antitumour potential (against breast, lung, cervical and hepatocellular carcinoma cell lines) of their methanolic extract, infusion and decoction (the most consumed forms) was evaluated and compared to the corresponding phenolic profile obtained by high performance liquid chromatography and mass spectrometry. Data obtained showed that the chemical profiles of wild and commercial samples, and also their methanolic extract, infusion and decoction were similar, varying only in the quantities found. Commercial yarrow have higher content of fat and saturated fatty acids, proteins, ash, energy value, sugars and flavonoids, while the wild sample revealed higher levels of carbohydrates, organic acids, unsaturated fatty acids, tocopherols and phenolic acids. The heterogeneity among the antioxidant and antitumour results of the samples and some low correlations with total phenolic compounds indicates that specific compounds, rather than the totality of them, are involved in the bioactive properties of samples.
- Chromatographic analysis of individual phenolic compounds in flowers and vegetative parts of wild Taraxacum sect. RuderaliaPublication . Dias, Maria Inês; Barros, Lillian; Alves, Rita C.; Oliveira, Beatriz; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.The vast genus of Taraxacum species, commonly known as dandelion, is often found in warm regions of the northern hemisphere. Used since ancient times in folk medicine for their curative properties, dandelion presents very interesting bioactive properties111• The incessant search and investigation for new and safe bioactive compounds is, nowadays, a milestone for ethnomedicine. In the present work, the individual phenolic profile of the methanolic extracts, infusions and decoctions of flowers and vegetative parts of wild Taraxacum sect Ruderalia was evaluated by HPLC-DAD/ESI-MS, and compared. Hydroxycinnamic acid derivatives were the major phenolic acids found in the samples, including caffeic acid derivatives, caffeoylquinic acid derivatives and chicoric acid; the latter was the main compound in all the preparations of vegetative parts and also in flowers decoction. Regarding flavonoids, it was only possible to tentatively identify luteolin derivatives on flowers and quercetin and luteolin derivatives on vegetative parts. The flowers methanolic extract showed the highest flavonoids content, mainly luteolin 0-hexoside (11.06 mg/g extract), while the vegetative parts extract gave the highest phenolic acids content (43.24 mg/g extract), mainly chicoric acid and its derivatives followed by caffeic acid and its derivatives. All the preparations showed similar phenolic profile although the methanolic extracts gave higher contents on total phenolics followed by infusions and decoctions. As far as we know, there are no previously reports on the comparison of the phenolic profile in different parts and preparations of dendalion. Due to the bioactive potential of phenolic compounds, further studies should be conducted in order to evaluate the role of the mentioned compounds in bioactivity of dendalion.
- A comparative study of bioactive properties of wild and commercial Achillea millefolium L.Publication . Dias, Maria Inês; Barros, Lillian; Carvalho, Ana Maria; Alves, Rita C.; Oliveira, Beatriz; Ferreira, Isabel C.F.R.Achillea millefolium L., commonly known as yarrow, is a medicinal plant with high bioactive value. Its infusion, decoction and alcoholic extract are widely used in Europe to treat digestive and intestinal problems, but also due to their antitumor, antimicrobial, anti-inflammatory and antioxidant properties [1]. In the present work, methanolic extract, infusion and decoction of wild and commercial yarrow were studied for their antioxidant properties and antitumor potential, evaluated by free radicals scavenging activity, reducing power and lipid peroxidation inhibition and by estimation of the growth inhibitory activity in human tumor cell lines, respectively. Overall, cultivated yarrow showed the highest antioxidant activity, presenting the lowest EC50 values. Decoctions of both samples revealed the highest DPPH scavenging activity (0.25 and 0.20 mg/ml, respectively), 13-carotene bleaching inhibition {0.18 and 0.22 mg/ml) and TBARS inhibition (0.04 and 0.08 mg/ml), while infusions presented the highest reducing power (0.12 and 0.13 mg/ml). The samples showed a higher lipid peroxidation inhibition, but a lower DPPH scavenging activity than methanolic extract of A. millefolium from Turkey (892.67 and 45.60 11g/ml, respectively) [2]. The infusion of wild yarrow showed the highest potential against breast (MCF-7; 8 150=17.04 1-Jg/ml) and hepatocellular (HepG2; 37.60 1-Jg/ml) carcinoma cell lines, while the methanolic extract of commercial yarrow was most potent against non-small cell lung (NCI H460; 26.64 IJg/ml), colon (HCT-15, 13.90 1-Jg/ml) and cervical (Hela, 19.68 IJg/ml) carcinoma cell lines. The results obtained with the decoction and infusion of cultivated yarrow against MCF-7 line are consistent with the ones reported with ethanolic extract of A. millefolium from Iran (8150=64 .078 1-Jg/ml) [3].This is a groundbreaking study on the comparison of different extracts of A. millefolium, showing that medicinal plants can be used not only in traditional medicine but also as a source of bioactive products, namely antioxidants and antitumorals.
- Detailed Phytochemical Composition, Cyto-/Hepatotoxicity, and Antioxidant/Anti-Inflammatory Profile of Moroccan Spices: A Study on Coriander, Caraway, and Mystical CuminPublication . Bouzaid, Hiba; Espírito Santo, Liliana; Ferreira, Diana M.; Machado, Susana; Costa, Anabela S.G.; Dias, Maria Inês; Calhelha, Ricardo C.; Barros, Lillian; Chater, Oumaima; Rodi, Youssef Kandri; Errachidi, Faouzi; Chahdi, Fouad Ouazzani; Oliveira, Beatriz; Alves, Rita C.Coriander, caraway, and mystical cumin are famous for their aromatic properties and widely used in Moroccan cuisine. The nutritional/phytochemical composition of their seeds (used for food flavoring and preservation) were compared. Their antioxidant, anti-inflammatory, cytotoxic and hepatotoxic effects were also explored. The fat content was similar among the samples (13%), with monounsaturated fatty acids being predominant. The coriander and mystical cumin seeds were extremely rich in C18:1n9c (81 and 85%, respectively) while, in the caraway, C18:1n12 (25%) was found together with C18:1n9c (32%). The caraway seeds also presented a higher proportion of C18:2n6c (34%) than the other seeds (13 and 8%, correspondingly). γ-Tocotrienol was the major vitamin E form in all the samples. The caraway seeds contained double the amount of protein (~18%) compared to the other seeds (~8%) but, qualitatively, the amino acid profiles among all seeds were similar. The seeds were also rich in dietary fiber (40–53%); however, differences were found in their fiber profiles. Caraway showed the highest antioxidant profile and anti-inflammatory activity and an LC-DAD-ESI/MSn analysis revealed great differences in the phenolic profiles of the samples. Cytotoxicity (NCI-H460, AGS, MCF-7, and CaCo2) and hepatotoxicity (RAW264.7) were not observed. In sum, besides their flavoring/preservation properties, these seeds are also relevant source of bioactive compounds with health-promoting activities.
- Exploring plant tissue culture to improve the production of phenolic compounds: a reviewPublication . Dias, Maria Inês; Sousa, Maria João; Alves, Rita C.; Ferreira, Isabel C.F.R.Plant tissue and organ culture has been extensively used from the beginning of the XX century for the study and comprehension of some primary biological mechanisms such as morphogenesis. However, with the increasing demand of the market for novel products derived from plants, in vitro culture became a reliable technique for the mass production of plant material. Moreover, the potential to use this technique for the production of some bioactive compounds, such as phenolic compounds, is immense since it allows the manipulation of the biosynthetic routes to increase the production and accumulation of specific compounds. This work intends to make a brief historical review of in vitro culture, highlighting its use for the production of bioactive compounds. Also, emphasizes the importance of phenolic compounds for the consumer as well reviews the metabolic pathways involved in its production in plant cells. Furthermore, it was carried out a comprehensive study on the work developed for the production of plant phenolic compounds in in vitro cultures, as well as on the type of elicitors used to increase of the same production; also a brief highlighting of the phenolic compounds which serve as elicitors. There are numerous reports directed to the production of phenolic extracts in in vitro plant cultures, however there is a lack in the production of individual phenolic compounds mainly due to the complexity of the biosynthetic routes and extraction procedures. Elicitation procedures are often used to increase the production of phenolics, archieving in most cases higher yields than in non-elicitated cultures. The increasing production of bioactive phenolic extracts/compounds allows for their further applicability, namely in the industry of functional foods or in pharmaceutical/medical fields.
- Improving bioactive compounds extractability of Amorphophallus paeoniifolius (Dennst.) NicolsonPublication . Costa, Anabela S.G.; Barreira, João C.M.; Ruas, Adilson; Vinha, Ana F.; Pimentel, Filipa B.; Alves, Rita C.; Ferreira, Isabel C.F.R.; Oliveira, BeatrizElephant foot yam (Amorphophallus paeoniifolius (Dennst.) Nicolson) is an underground, unbranched deciduous plant that produces a large tubercle (rhizome) with recognized health effects. In this study, the influence of solvent nature (water, water/etanol (1:1) and absolute ethanol) and processing type (fresh, lyophilized and boiled) on the antioxidant activity and bioactive compounds extractability of elephant foot yam was evaluated. Extracts were compared for their contents in total phenolics, flavonoids and tannins. Moreover, their antioxidant capacity was assessed by the ferric reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH▪) scavenging capacity assays. Phenolics (154 mg GAE/L) and tannins (109 mg GAE/L) were maximized in lyophilized samples extracted with the hydroalcoholic solvent, which attained also the highest FRAP value (711 mg FSE/L). In turn, flavonoids reached the highest yields in lyophilized samples (95 mg ECE/L) extracted with pure ethanol, as well as the highest DPPH▪ scavenging activity. These findings might have practical applications to define the best processing methodology regarding the enhancement of elephant foot yam, either for prompt consumption, as well as to develop food supplements or pharmaceutical related products.