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- Antioxidant activities, distribution of phenolics and free amino acids of Erica australis L. leaves and flowers collected in Algarve, PortugalPublication . Nunes, Ricardo; Carvalho, Isabel Saraiva deLeaves and flowers from Erica plant possess nutritional and medicinal properties. We determined the antioxidant activity, phenolic, flavonoid and amino acid profiles of the leaves and flowers of this plant. Total amino acid content varied from 28 to 49 and essential amino acids from 8 to 20mg/g for flowers and leaves, respectively, with different distributions within the plant. From 16 phenolic compounds identified, delphinidin-3-glucoside, caffeic acid and cyanidin-3,5-glucoside in leaves and pelargonidin-3,5-glucoside in flowers were the compounds in highest amount, all with over 500g/g. Although flowers had higher contents of phenolic compounds (4000g/g) than leaves (3400g/g), they showed lower antioxidant activity, indicating that the antioxidant activity depends not only on the content of phenolics, but also on their type. This study shows that this plant has the potential to be used as an extra dietary source of amino acids and phenolic compounds and its consumption may provide health benefits.
- Antioxidant and free radical scavenging activities of different plant parts from two Erica speciesPublication . Nunes, Ricardo; Anastácio, Ana; Carvalho, Isabel Saraiva deAqueous extractions from two species of Erica consumed as infusions in several countries to heal ailments were investigated for their phenolic and flavonoid contents, along with antioxidant capacity and radical scavenging capacity using total antioxidant activity, ferric-reducing antioxidant power, reducing power, 1,1-diphenyl-2-picrylhydrazyl and 2-2'-azino-bis(3 ethylbenzothiazoline-6-sulfonic acid) radicals, respectively. Antioxidant properties and total phenolic content differed significantly among these plants. Aqueous extracts of leaves possessed, on average, the highest antioxidant capacity and phenolic content (34.09 ± 10.81 mg ascorbic acid equivalent/g dry weight and 30.59 ± 10.19 mg gallic acid equivalent/g dry weight, respectively) of all three plant parts. A significant correlation (r2 = 0.952) between antioxidant capacity and total phenolic content was found, indicating that phenolic compounds are the major contributors to the antioxidant properties of these plants. Upon application of hierarchical cluster analysis to the results obtained, leaves with flowers were grouped in one cluster, whereas branches remained in another cluster, showing little interference from the collection site or species factors.
- Antibacterial, antioxidant and anti-proliferative properties and zinc content of five south Portugal herbsPublication . Nunes, Ricardo; Pasko, Pawel; Tyszka-Czochara, Malgorzata; Szewczyk, Agnieszka; Szlosarczyk, Marek; Saraiva de Carvalho, IsabelContext: Crataegus monogyna L. (Rosaceae) (CM), Equisetum telmateia L. (Equisataceae) (ET), Geranium purpureum Vil. (Geraniaceae) (GP), Mentha suaveolens Ehrh. (Lamiaceae) (MS), and Lavandula stoechas L. spp. luisieri (Lamiaceae) (LS) are all medicinal. Objective: To evaluate the antioxidant, antiproliferative and antimicrobial activities of plant extracts and quantify individual phenolics and zinc. Material and methods: Aerial part extracts were prepared with water (W), ethanol (E) and an 80% mixture (80EW). Antioxidant activity was measured with TAA, FRAP and RP methods. Phenolics were quantified with a HPLC. Zinc was quantified using voltammetry. Antibacterial activity (after 48 h) was tested using Enterococcus faecalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes. Antiproliferative activity (after 24 h) was tested using HEP G2 cells and fibroblasts. Results: Solvents influenced results; the best were E and 80EW. GP had the highest antioxidant activity (TAA and FRAP of 536.90mg AAE/g dw and 783.48mg TE/g dw, respectively). CM had the highest zinc concentration (37.21 mg/kg) and phenolic variety, with neochlorogenic acid as the most abundant (92.91 mg/100 g dw). LS was rich in rosmarinic acid (301.71 mg/100 g dw). GP and LS inhibited the most microorganisms: B. cereus, E. coli and S. aureus. GP also inhibited E. faecalis. CM had the lowest MIC: 5830 mu g/mL. The antibacterial activity is explained by the phenolics present. LS and CM showed the most significant anti-proliferative activity, which is explained by their zinc content. Conclusion: The most promising plants for further studies are CM, LS and GP.
- Identification of Predominant Phytochemical Compounds and Cytotoxic Activity of Wild Olive Leaves (Olea europaea L. ssp sylvestris) Harvested in South PortugalPublication . Makowska-Was, Justyna; Galanty, Agnieszka; Gdula-Argasinska, Joanna; Tyszka-Czochara, Malgorzata; Szewczyk, Agnieszka; Nunes, Ricardo; Carvalho, Isabel S.; Michalik, Marta; Pasko, PawelThis study has been aimed at providing a qualitative and quantitative evaluation of selected phytochemicals such as phenolic acids, flavonoids, oleuropein, fatty acids profile, and volatile oil compounds, present in wild olive leaves harvested in Portugal, as well as at determining their antioxidant and cytotoxic potential against human melanoma HTB-140 and WM793, prostate cancer DU-145 and PC-3, hepatocellular carcinoma Hep G2 cell lines, as well as normal human skin fibroblasts BJ and prostate epithelial cells PNT2. Gallic, protocatechuic, p-hydroxybenzoic, vanillic acids, apigenin 7-O-glucoside, luteolin 7-O-glucoside, and rutin were identified in olive leaves. The amount of oleuropein was equal to 22.64 g/kg dry weight. (E)-Anethole (32.35%), fenchone (11.89%), and (Z)-3-nonen-1-ol (8%) were found to be the main constituents of the oil volatile fraction, whereas palmitic, oleic, and alpha-linolenic acid were determined to be dominating fatty acids. Olive leaves methanol extract was observed to exerted a significant, selective cytotoxic effect on DU-145 and PC-3 cell lines. Except the essential oil composition, evaluated wild olive leaves, with regard to their quantitative and qualitative composition, do not substantially differ from the leaves of other cultivars grown for industrial purposes and they reveal considerable antioxidant and cytotoxic properties. Thus, the wild species may prove to be suitable for use in traditional medicine as cancer chemoprevention.
- The cholesterol 24-hydroxylase activates autophagy and decreases mutant huntingtin build-up in a neuroblastoma culture model of Huntington’s diseasePublication . Nóbrega, Clévio; Conceição, André; Costa, Rafael G; Koppenol, Rebekah; Sequeira, Raquel L.; Nunes, Ricardo; Carmo-Silva, Sara; Marcelo, Adriana; Matos, Carlos A; Betuing, Sandrine; Caboche, Jocelyne; Cartier, Nathalie; Alves, SandroObjective Compromised brain cholesterol turnover and altered regulation of brain cholesterol metabolism have been allied with some neurodegenerative diseases, including Huntington’s disease (HD). Following our previous studies in HD, in this study we aim to investigate in vitro in a neuroblastoma cellular model of HD, the effect of CYP46A1 overexpression, an essential enzyme in cholesterol metabolism, on huntingtin aggregation and levels. Results We found that CYP46A1 reduces the quantity and size of mutant huntingtin aggregates in cells, as well as the levels of mutant huntingtin protein. Additionally, our results suggest that the observed beneficial effects of CYP46A1 in HD cells are linked to the activation of autophagy. Taken together, our results further demonstrate that CYP46A1 is a pertinent target to counteract HD progression.
- Effect of Erica australis extract on Caco-2 cells, fibroblasts and selected pathogenic bacteria responsible for wound infectionPublication . Nunes, Ricardo; Rodrigues, Susana; Pasko, Pawel; Tyszka-Czochara, Malgorzata; Grenha, Ana; Carvalho, Isabel Saraiva dePlants from the genus Erica are used in many countries to treat several ailments. In this work we intend to evaluate the potential in vivo benefits of Erica australis L. by testing in vitro the effect induced by the plant extract when in contact with BJ fibroblasts (3 and 9 hours) and Caco-2 cells (3, 6 and 24 hours). Effects on five pathogenic microorganisms(Enterococcus faecalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus and Listeria monocytogenes) were also determined. It was found that the extracts enhanced fibroblast proliferation (maximum of 484% of control at 6 hour exposure) while Caco-2 cells viability was reduced in a concentration and time dependent manner (minimum of 22.3% of control at 24 hour exposure). Antimicrobial effects were also detected, with differences registered among the plant parts and solvent used, with the lowest minimum concentration for diffusion inhibition (MCDI) of 1 mg/mL. Results obtained with the fibroblasts and bacteria strongly show that this plant has potential to be used in wound healing as a stimulant of fibroblast growth and disinfection, as well as an antibiotic. Results obtained with Caco-2 cells indicate this plant also has some potential for and application as anticancer agent.