Percorrer por autor "Gonçalves, Sandra"
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- Accumulation of phenolic compounds in in vitro cultures and wild plants of Lavandula viridis L'Her and their antioxidant and anti-cholinesterase potentialPublication . Costa, Patrícia; Gonçalves, Sandra; Valentão, Patrícia; Andrade, Paula B.; Romano, AnabelaIn this study, we evaluated the phenolic profile, antioxidant and anti-cholinesterase potential of different extracts from wild plants and in vitro cultures of Lavandula viridis L'Her. The HPLC-DAD analysis allowed the identification and quantification of 3-0-caffeoylquinic, 4-0-caffeoylquinic, 5-0-caffeoylquinic and rosmarinic acids, and luteolin and pinocembrin. Water/ethanol extract from in vitro cultures contained the highest amount of the identified phenolic compounds (51652.92 mg/kg). To investigate the antioxidant activity we used Trolox equivalent antioxidant capacity, oxygen radical absorbance capacity, Fe2+ chelation activity and the inhibition of Fe2+-induced lipid peroxidation in mouse brain homogenates (in vitro). Overall, all the extracts from both wild plants and in vitro cultures exhibited ability to scavenge free radicals, to chelate Fe2+ and to protect against lipid peroxidation. In addition, the extracts from L. viridis were active in inhibiting both acetylcholinesterase and butyrylcholinesterase (Ellman's method). Our findings suggest that L. viridis in vitro cultures represent a promising alternative for the production of active metabolites with antioxidant and anti-cholinesterase activity. (C) 2013 Elsevier Ltd. All rights reserved.
- Allelopathic effects of extracts from several plant species on seed germination and seedlings growth of Lactuca sativa LPublication . Gonçalves, Sandra; Franco, J.; Romano, AnabelaThe ability of a plant species to inhibit germination of other plants is an untapped resource for weed control in crops that could revolutionize organic crop production. The main objective of this study was to evaluate the allelopathic potential of aqueous (5 and 10%, w/v) and methanolic (50mg ml-1) extracts from several plant species (Arbustus unedo L., Ericaceae; Daphne gnidium L., Thymeleaceae; Myrtus communis L., Myrtaceae; Olea europea L., Oleaceae; Pistacia lentiscus L., Anacardiacceae; Quercus suber L., Fagaceae; Ruscus aculeatus L., Liliaceae, Rhododendron ponticum subsp baeticum (Boissier & Reuter) Handel-Mazzetti, Ericaceae) on seed germination and seedling growth of Lactuca sativa. To test the phytotoxicity 500µl of the extract were added separately over filter papers (9cm diameter) in Petri dishes. It was observed that methanolic extracts from M. communis and R. aculeatus completely inhibited seed germination, and almost all the extracts tested reduced seed germination and/or seedling growth. The inhibition of root growth was generally higher than of shoot growth, with the highest percentages of root inhibition being observed with the aqueous extracts of D. gnidium (80 and 72% for the extract at 5 and 10%, respectively) and R. aculeatus (74 and 78%), and with the methanolic extract of Q. suber (74%). Besides inhibiting seedling growth other morphological abnormalities occurred in the presence of the extracts. Roots of treated plants were thicker with a brownish color as compared to controls. Studies are being conducted to investigate the phytotoxic effect of the extracts on physiological and biochemical processes during germination and seedlings growth.
- Aluminum inhibits root growth and induces hydrogen peroxide accumulation in Plantago algarbiensis and P. almogravensis seedlingsPublication . Martins, Neusa; Gonçalves, Sandra; Romano, AnabelaWe have evaluated the impact of aluminum (Al) on germination, relative root growth, Al accumulation in roots tips, H2O2 levels, plasma membrane integrity, pigment levels, protein content, and the activities of superoxide dismutase (SOD) and catalase (CAT) in seedlings of the endangered Portuguese species Plantago algarbiensis and Plantago almogravensis. We found that up to 400 μM Al had no impact on the germination percentage in either species but inhibited root growth in a concentration-dependent manner (more severely in P. algarbiensis). Al accumulation in the root tips of both species was concentration dependent up to 200 μM but declined thereafter despite the absence of membrane damage. We observed a concentration-dependent induction of SOD activity but no change in CAT activity resulting in the accumulation of H2O2 (a known growth inhibitor), although its impact in P. almogravensis may be partially ameliorated by the accumulation of carotenoid pigments. Our data suggest an association between Al uptake, H2O2 production, and the inhibition of root growth during early seedling development in P. algarbiensis and P. almogravensis, although the latter is more tolerant towards higher concentrations of the metal. © 2013 Springer-Verlag Wien.
- An efficient in vitro propagation protocol for Pinguicula lusitanica, a rare insectivorous plantPublication . Gonçalves, Sandra; Escapa, Ana Luísa; Grevenstuk, Tomás; Romano, AnabelaIn this study, an efficient protocol was developed for in vitro propagation of Pinguicula lusitanica L., a rare insectivorous plant with pharmacological value and limited reproductive capacity. The effects of two concentrations (0.1 and 0.5 mg l-1) of a range of plant growth regulators, including cytokinins (BA, KIN, and ZEA) and auxins (IAA, IBA, and NAA), and three concentrations of MS medium macronutrients (total, 1/2 and 1/4MS) on proliferation and rooting, were investigated. P. lusitanica shoots showed abundant proliferation and rooting capacity, both of which were significantly influenced by MS medium strength. The use of 1/2MS supplemented with 0.5 mg l-1 BA or KIN ensure a 29-fold rate of proliferation. Best rooting frequency and higher root number and length were attained in 1/4MS medium containing 0.2 mg l-1 IAA. Sixty percent of the plantlets were successfully acclimatized to ex vitro conditions, exhibiting normal development. These plantlets can be used to replenish declining populations in the wild and/or for the extraction of bioactive compounds, reducing pressure on wild stocks.
- Analysis of the volatiles emitted by whole flowers and isolated flower organs of the carob tree using HS-SPME-GC/MSPublication . Custódio, Luísa; Serra, Hugo; Nogueira, José Manuel F.; Gonçalves, Sandra; Romano, AnabelaThe volatiles emitted by fresh whole flowers and isolated flower organs of male, female, and hermaphrodite carob trees (Ceratonia siliqua L.; Leguminosae)were analyzed by headspace solid-phase microextraction followed by capillary gas chromatography and mass spectrometry. The headspace of carob flowers is mainly constituted of high amounts of monoterpenes and sesquiterpenes, and more than 25 compounds were identified. The gender and cultivar affected both the qualitative profile and the relative abundances of the volatiles of whole flowers and isolated floral organs. Linalool and its derivatives (cis-linalool furan oxide, 2,2,6-trimethyl-3-keto-6-vinyltetrahydropyran, cis-linalool pyran oxide, and trans-linalool furan oxide), a-pinene, and a-farnesene were the dominant volatiles. Female flowers had a higher diversity of volatile compounds than males and hermaphrodites, but a lower abundance of the major ones. Similarly, the floral scent of female flowers of cv. Mulata had a higher content of volatiles but a lower abundance of the major ones, when compared to cv. Galhosa. In each of the three gender types of flowers, the nectary disks seemed to be the major source of volatiles.
- Anti-obesogenic effects of plant natural products: A focus on Korean traditional foodsPublication . Das, Gitishree; Jiménez Ortega, Luis Alfonso; Gonçalves, Sandra; Heredia, J. Basilio; Pereira, Maria de Lourdes Gomes; Shin, Han-Seung; Romano, Anabela; Jayanta Kumar PatraNatural products from food can play an important role in obesity management. Korean traditional food (KTF), characterized by a high inclusion of fresh or prepared vegetables, a reasonable contribution of fish, pulses, and with very little amount of meat, is one of the most recognized cuisines for its nutritional quality, diversity, and flavor. The traditional Korean food contains relevant phytochemicals and probiotic microorganisms with anticancer, anti-mutagenic, antioxidant, and anti-obesogenic properties. Scope: Obesity is a chronic degenerative pathology which causes adverse effects on health, low quality of life, and social costs. The use of fermentation as a conservation/preparation method increases the functional value of KTF, conferring new medicinal properties such as anti-obesogenic. Key findings and conclusions: This review article summarizes data about the anti-obesogenic properties of phytochemicals and KTF. Reviewed results indicated that several phytochemicals present in KTF (e.g., flavonoids, saponins, terpenes) exerted anti-obesogenic effects due to their antioxidant, anti-inflammatory, inhibition of enzymes related to lipid and carbohydrate metabolism, inflection of lipid homeostasis, thermogenic, life cycle of adipocyte, and appetite suppression. Besides, both in vivo and medical research have showed that fermented products extensively included in KTF have a positive effect on the reduction of obesity through different mechanisms particularly by altering human metabolism and affecting gut microbiota. Some molecular mechanisms among these anti-obesogenic agents, are referred in research, focused on the search for phytochemicals that can intervene with leptin sensitizers, GLP1/glucagon dual agonists, GIP/GLP1/glucagon tri-agonists, amylin/calcitonin dual agonists, Y2R agonists, GIP/GLP1 dual agonists, drugs targeting the ghrelin pathway, and GLP1R agonists. Overall, the current review highlights the anti-obesogenic impact of KTF in accordance with the low rate of obesity in the Korean population.
- Antimicrobial activity of Drosophyllum lusitanicum, an endemic Mediterranean insectivorous plantPublication . Gonçalves, Sandra; Quintas, Célia; Gaspar, Maria Nelma; Nogueira, José Manuel F.; Romano, AnabelaThe aim of this study was to evaluate the antimicrobial activity of Drosophyllum lusitanicum leaf extract against various yeasts and bacteria species, including both standard and clinically isolated strains. The extract exhibited strong antimicrobial activity against all the tested yeast strains with inhibition zones ranging 23.67–42.23mm and with minimum inhibitory concentration (MIC) values ranging 31–63 mgL 1. All the Gram-positive bacteria studied were inhibited by the extract, showing inhibition zones ranging 17.67–43.00mm and MIC values comprising between 15.6 and 250 mgL 1. In contrast, the growth of the tested Gram-negative bacteria was not significantly affected by the extract. Among the microorganisms tested, Staphylococcus epidermidis ATCC 12228 was the most sensitive, presenting the lowest MIC value (15.6 mgL 1), while Enterococcus faecalis ATCC 29212 was the most tolerant (250 mgL 1). The extract of D. lusitanicum was analysed by gas chromatography-mass spectrometry and the major constituent found was plumbagin.
- Antioxidant activity and inhibitory effect of L. viridis extract on Fe2+-induced lipid peroxidation in brain homogenatesPublication . Costa, Patrícia; Gonçalves, Sandra; Romano, AnabelaThe brain is particularly susceptible to oxidative stress damaging effects due such events as the high consumption of oxygen, limited concentration of antioxidants and a relatively high degree of polyunsaturated fatty acids that are particularly good substrates for peroxidation reactions [1–3]. Oxidative stress could lead to damage biological target molecules, affecting the cellular function and integrity [4]. The ability of natural antioxidants, mainly phenolic compounds, to protect cells from oxidative stress has been previously demonstrated [5]. In this work, the methanol extract from Lavandula viridis L'Hér. (Lamiaceae), a xerophytic aromatic shrub endemic to the south-west Iberian Peninsula [6], was investigated for its effect on deoxyribose degradation, its reducing properties, Fe2+-chelating ability and total phenol content. The capacity of this extract to prevent Fe2+-induced lipid peroxidation in mouse brain (in vitro) was also evaluated. L. viridis extract showed Fe2+ chelating activity, reducing power and the ability to prevent Fe2+/H2O2-induced decomposition of deoxyribose in a dose-dependent manner. This extract also revealed a high phenol content (893.01±17.09µmol gallic acid equivalents/g extract) evaluated by Folin-Ciocalteu method. Moreover, in brain homogenates, the methanol extract of L. viridis caused a high decrease in the MDA production in both the basal and the Fe2+-induced lipid peroxidation. The effective protective properties of L. viridis could be attributed to its higher phenol content, Fe2+ chelating ability, reducing properties and HO· radical scavenging ability. The findings suggest that methanol extract from L. viridis could be a potential source of natural antioxidants.
- Antioxidant activity and verbascoside content in extracts from two uninvestigated endemic Plantago spp.Publication . Gonçalves, Sandra; Grevenstuk, Tomás; Martins, Neusa; Romano, AnabelaThis work describes for the first time the antioxidant activity of extracts from wild plants and in vitro cultures of two previously uninvestigated Plantago spp. endemic to Portugal, Plantago algarbiensis Samp. and Plantago almogravensis Franco. The Well-known and widely distributed species Plantago lagopus L. was also studied for comparison. Although the extracts from the three species exhibited radical scavenging and iron-reducing properties, the extracts from the two endemic species showed greater activity irrespectively of plant material source. Both P. algarbiensis extracts showed similar antioxidant activity whereas, in the case of P. almogravensis higher activity was observed for extracts from wild plants compared to extracts from in vitro cultures. Liquid chromatography-diode array detection analyses indicate verbascoside as a major constituent of all extracts and the highest content was obtained from in vitro cultures algarbiensis. In addition, a high correlation-between-the anti-oxidant-activity measured with three. methods and the total phenolic content was found, but no correlation was observed between antioxidant activity and verbascoside content. The results suggest that P. algarbiensis and P. almogravensis are sources of health-beneficial phytochemicals and indicate that in vitro cultures represent a promising alternative for the biosynthesis of verbascoside. (C) 2014 Elsevier B.V. All rights reserved.
- Antioxidant and anti-cholinesterase activities of Lavandula viridis L’Hér extracts after in vitro gastrointestinal digestionPublication . Costa, Patrícia; Grevenstuk, Tomás; Costa, Ana M. Rosa da; Gonçalves, Sandra; Romano, AnabelaLavandula viridis L’Hér is an aromatic shrub with relevant biological activities associated to the presence ofphenolic compounds. However, these compounds must be bioavailable to exert their biological function.Therefore, in this study, we investigated the influence of the L. viridis extract matrices on the digestion ofthe main component rosmarinic acid and their antioxidant and anti-cholinesterase activities after in vitrogastrointestinal digestion. Overall, the antioxidant and anti-cholinesterase activities were assured afterin vitro gastrointestinal processes and we observed that the L. viridis extract matrices have an importantrole in the bioactive effects of their main compound, rosmarinic acid. The L. viridis extracts and rosmarinicacid did not show any toxic effect on colon adenocarcinoma Caco-2 cell viability. Finally, the compoundsfrom L. viridis extracts were not metabolized by Caco-2 cells and were not able to permeate into them.