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  • A comparative study of the in vitro enzyme inhibitory and antioxidant activities of Butea monosperma (Lam.) Taub. and Sesbania grandiflora (L.) Poiret from Pakistan: New sources of natural products for public health problems
    Publication . Baessa, M.; Rodrigues, Maria João; Pereira, Catarina; Santos, T.; Neng, N. da Rosa; Nogueira, J. M. F.; Barreira, Luísa; Varela, J.; Ahmed, H.; Asif, S.; Boukhari, S. A.; Kayani, W. K.; Ahmad, Khawaja Shafique; Zengin, G.; Mollica, A.; Custódio, Luísa
    Infusions, decoctions and tinctures were prepared from flowers of Butea monosperma (Lam.) Taub. and Sesbania grandiflora (L.) Poiret and evaluated for in vitro inhibition of enzymes implicated on the onset of neurological diseases (acetylcholinesterase: AChE and butyrylcholinesterase: BuChE), diabetes (alpha-glucosidase and alpha-amylase), obesity (lipase) and skin hyperpigmentation (tyrosinase). Extracts were also appraised for radical scavenging activity (RSA) on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, and for metal chelating activity on copper and iron ions. Samples were evaluated for their total contents in different phenolics groups by spectrophotometric methods, for phenolic profile by high performance liquid chromatography e diode array detection (HPLC-DAD) and for mineral contents by microwave plasma-atomic emission spectrometry (MP-AE). Regarding B. monosperma, the tincture allowed for a moderate inhibition of AChE, the decoction was able to inhibit alpha-glucosidase and no activity was observed towards BuChE, alpha-amylase or lipase. All extracts had a low or moderate inhibition towards tyrosinase, and significant RSA and metal chelating potential. As for S. grandiflora, only the decoction inhibited AChE, none of the extracts was able to inhibit BuChE, all samples inhibited alpha-glucosidase and infusions and decoctions had similar inhibitory properties towards alpha-amylase. None of the extracts was active against lipase, but all were able to inhibit tyrosinase. Extracts had also significant RSA, moderate copper chelation and decoctions had the capacity to chelate iron. The most abundant macroelements in both species were potassium and calcium, while iron was the prevalent microelement, especially in B. monosperma. Both species had significant levels of phenolic compounds, and the main components in decoctions and infusions of B. monosperma were syringic and salicylic acids, while the major compound identified in tinctures was the flavonoid luteolin-7-O-glucoside. In S. grandiflora the most abundant were chlorogenic and neochlorogenic acids and catechin hydrate. Molecular docking studies on the most abundant molecules in S. grandiflora, (+)-catechin, chlorogenic acid and neochlorogenic acid, indicate that these compounds are able to dock to alpha-glucosidase in a similar manner than acarbose. Our results suggest that flowers of both species are a promising source of high value-added compounds with enzyme inhibitory and antioxidant properties. (c) 2018 SAAB. Published by Elsevier B.V. All rights reserved.
  • Exploring Caralluma europaea (Guss.) NEBr. as a potential source of bioactive molecules: In vitro antioxidant and antidiabetic properties, and phenolic profile of crude extracts and fractions
    Publication . Dra, Loubna Ait; Rodrigues, Maria Joao; Neng, Nuno da Rosa; Nogueira, Jose M. F.; Elamine, Youssef; Aghraz, Abdellah; Markouk, Mohamed; Larhsini, Mustapha; Custódio, Luísa
    Caralluma europaea (Guss.) N.E.Br is a succulent medicinal species used in the Moroccan traditional medicine for its anticancer and antidiabetic properties. In this work, this species was explored for the in vitro antidiabetic and antioxidant properties of crude methanol and dichloromethane extracts, and obtained fractions, from its aerial organs. In vitro antidiabetic properties were evaluated towards baker's yeast and rat's intestinal alpha-glucosidase, and alpha-amylase. Four in vitro methods were used to appraise the antioxidant potential, namely radical scavenging activity (RSA) on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and iron and copper chelating assays. Finally, the profile of the main phenolic compounds present in the samples was assessed by high-performance liquid chromatography equipped with diodearray detection (HPLC-DAD). The highest inhibition of baker's yeast alpha-glucosidase was obtained with the methanol extract (87%), and its fractions, with a maximum inhibition of 83% at the concentration of 10 mg/ml. The most significant inhibition of mammalian alpha-glucosidase was obtained with the dichloromethane crude extract (85%), and corresponding fractions at 10 mg/ml. Moderate activity was achieved with the two extracts against a-amylase (52-53%) at 10 mg/ml, but no relevant activity was detected for most fractions. Crude extracts had a significant RSA against DPPH and ABTS, with range values of 83-98% (methanol extracts) and 53-80% (dichloromethane extracts). Fractions from the methanol extract were more active against tested radicals. Crude extracts had chelating activity on both metals, and the highest copper chelation was achieved with the methanol extract, while the dichloromethane extract and the majority of fractions from both extracts presented the highest iron chelation at 10 mg/ml. A total of 21 phenolic compounds were identified and quantified by HPLC-DAD in the samples, and the main compounds detected were catechine hydrate and salicylic and caffeic acids. Our results suggest that C. europaea extracts contain compounds with in vitro antioxidant and antidiabetic properties with potential applications in the pharmaceutical and food industries.
  • New insights into the phytochemical profile and biological properties of Lycium intricatum Bois. (Solanaceae)
    Publication . Bendjedou, Houaria; Benamar, Houari; Bennaceur, Malika; Rodrigues, Maria João; Pereira, Catarina Guerreiro; Trentin, Riccardo; L, Custódio
    This work aimed to boost the valorisation of Lycium intricatum Boiss. L. as a source of high added value bioproducts. For that purpose, leaves and root ethanol extracts and fractions (chloroform, ethyl acetate, n-butanol, and water) were prepared and evaluated for radical scavenging activity (RSA) on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,20 -azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, ferric reducing antioxidant power (FRAP), and metal chelating potential against copper and iron ions. Extracts were also appraised for in vitro inhibition of enzymes implicated on the onset of neurological diseases (acetylcholinesterase: AChE and butyrylcholinesterase: BuChE), type-2 diabetes mellitus (T2DM, α-glucosidase), obesity/acne (lipase), and skin hyperpigmentation/food oxidation (tyrosinase). The total content of phenolics (TPC), flavonoids (TFC), and hydrolysable tannins (THTC) was evaluated by colorimetric methods, while the phenolic profile was determined by high-performance liquid chromatography, coupled to a diode-array ultraviolet detector (HPLCUV-DAD). Extracts had significant RSA and FRAP, and moderate copper chelation, but no iron chelating capacity. Samples had a higher activity towards α-glucosidase and tyrosinase, especially those from roots, a low capacity to inhibit AChE, and no activity towards BuChE and lipase. The ethyl acetate fraction of roots had the highest TPC and THTC, whereas the ethyl acetate fraction of leaves had the highest flavonoid levels. Gallic, gentisic, ferulic, and trans-cinnamic acids were identified in both organs. The results suggest that L. intricatum is a promising source of bioactive compounds with food, pharmaceutical, and biomedical applications.
  • Biological activities and chemical composition of methanolic extracts of selected Autochthonous microalgae strains from the Red Sea
    Publication . Pereira, Hugo; Custodio, Luisa; Rodrigues, Maria Joao; Bruno De Sousa, Carolina; Oliveira, Marta; Barreira, Luísa; Neng, Nuno da Rosa; Florencio Nogueira, Jose Manuel; Alrokayan, Salman A.; Mouffouk, Fouzi; Abu-Salah, Khalid M.; Ben-Hamadou, Radhouan; Varela, João
    Four lipid-rich microalgal species from the Red Sea belonging to three different genera (Nannochloris, Picochlorum and Desmochloris), previously isolated as novel biodiesel feedstocks, were bioprospected for high-value, bioactive molecules. Methanol extracts were thus prepared from freeze-dried biomass and screened for different biological activities. Nannochloris sp. SBL1 and Desmochloris sp. SBL3 had the highest radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, and the best copper and iron chelating activities. All species had potent butyrylcholinesterase inhibitory activity (>50%) and mildly inhibited tyrosinase. Picochlorum sp. SBL2 and Nannochloris sp. SBL4 extracts significantly reduced the viability of tumoral (HepG2 and HeLa) cells with lower toxicity against the non-tumoral murine stromal (S17) cells. Nannochloris sp. SBL1 significantly reduced the viability of Leishmania infantum down to 62% (250 mu g/mL). Picochlorum sp. SBL2 had the highest total phenolic content, the major phenolic compounds identified being salicylic, coumaric and gallic acids. Neoxanthin, violaxanthin, zeaxanthin, lutein and -carotene were identified in the extracts of all strains, while canthaxanthin was only identified in Picochlorum sp. SBL2. Taken together, these results strongly suggest that the microalgae included in this work could be used as sources of added-value products that could be used to upgrade the final biomass value.
  • Searching for new sources of innovative products for the food industry within halophyte aromatic plants: In vitro antioxidant activity and phenolic and mineral contents of infusions and decoctions of Crithmum maritimum L.
    Publication . Pereira, Catarina Guerreiro; Barreira, Luísa; Neng, Nuno da Rosa; Florencio Nogueira, Jose Manuel; Marques, Catia; Santos, Tamara; Varela, J.; Custódio, Luísa
    Aromatic halophyte plants are an outstanding source of bioactive compounds and natural products with potential use in the food industry. This work reports the in vitro antioxidant activity, toxicity, poly phenolic profile and mineral contents of infusions and decoctions from stems, leaves and flowers of Crithmum maritimum L, an aromatic and edible maritime halophyte (sea fennel). Aspalathus linearis (Burm.f.) Dahlg. (rooibos) herbal tea was used as a reference. Sea fennel's tisanes, particularly from leaves, were rich in phenolic compounds and five of them (p-hydroxybenzoic and ferulic acids, epicatechin, pyrocatechol and 4-hydroxybenzaldehyde) were here described in C maritimum for the first time. Chlorogenic acid was the dominant phenolic determined. Na was the most abundant mineral in all tisanes followed by Ca and Mg in leaves' tisanes and K in flowers. Sea fennel's samples had a similar antioxidant activity than those from A. linearis, and had no significant toxicity towards four different mammalian cell lines. Altogether, our results suggest that sea fennel can be a source of products and/or molecules for the food industry with antioxidant properties and minerals in the form, for example, of innovative health-promoting herbal beverages.
  • In vitro and in silico approaches to appraise Polygonum maritimum L. as a source of innovative products with anti-ageing potential
    Publication . Rodrigues, Maria Joao; Slusarczyk, Sylwester; Pecio, Łukasz; Matkowski, Adam; Salmas, Ramin Ekhteiari; Durdagi, Serdar; Pereira, Catarina; Varela, J.; Barreira, Luísa; Custódio, Luísa
    Different Polygonum species have in vitro neuroprotective properties and are traditionally used for their anti-ageing benefits. In this context this work explored for the first time P. maritimum (sea knotgrass) as a potential source of natural products with industrial application as cognitive enhancers with anti-ageing potential. For that purpose methanol and dichloromethane extracts were prepared from leaves and roots of that species and evaluated for in vitro neuroprotective effects through the inhibition on acetyl- (AChE) and butyrylcholinesterase (BuChE), protection against hydrogen peroxide (H2O2)-induced cytoxicity on neuroblastoma cells and lipopolysaccharide (LPS)-induced neuroinflammation on microglia cells. The extracts were chemically characterized by ultra-high-pressure liquid chromatography (UHPLC) coupled to tandem mass spectrometry (MS/MS) and docking studies were performed on the identified compounds. Methanol extracts had the highest activity in AChE (leaves: IC50 = 0.27 mg/mL; roots: IC50 = 0.17 mg/mL) and BuChE (leaves: IC50 = 0.62 mg/mL; roots: IC50 = 0.61 mg/mL) inhibition, as well as reduction of nitric oxide (NO) production in LPS-treated microglia (leaves: IC50 = 4.17 μg/mL; roots: IC50 = 9.95 μg/mL). Methanol extracts prevented oxidative stress-induced cytotoxicity in SH-SY5Y cells when applied simultaneously with H2O2, whereas cells pre-treated with the dichloromethane extracts had increased viability. Fifteen flavonoids were identified and showed favorable binding energies to AChE and BuChE binding pockets. These data suggests P. maritimum as a promising source of natural products and/or molecules with cognitive enhancement and anti-ageing properties.
  • Juncaceae species as sources of innovative bioactive compounds for the food industry: In vitro antioxidant activity, neuroprotective properties and in silico studies
    Publication . Rodrigues, Maria João; Gangadhar N. Katkam, Dr.; Zengin, Gokhan; Mollica, Adriano; Varela, João; Barreira, Luísa; L, Custódio
    Several Juncus species are traditionally used as sedative and to treat health problems like insomnia. This work was based on the hypothesis that Juncus acutus, J. maritimus and J. inflexus may have molecules with bioactivities relevant for the improvement of cognitive functions and thus with potential use as food additives and/or nutraceuticals. Therefore leaves and roots extracts of those species were evaluated for radical scavenging (RSA) and metal chelating activities, and for in vitro inhibition of acetyl-(AChE) and butyrylcholinesterase (BuChE). The bioactive compound was isolated and identified by HPLC-DAD, and its anticholinesterase capacity was determined by different assays. Docking studies were performed to elucidate its inhibitory mechanism. The dichloromethane root extract of J. acutus had the highest RSA against DPPH and ABTS radicals, and the dichloromethane extract of J. maritimus leaves had the uppermost FRAP. The dichloromethane extract from J. acutus leaves had the strongest BuChE inhibition. Juncunol was the bioactive compound, exhibiting dual anticholinesterase capacity on enzyme-based assays and AChE inhibition in neuronal and glial cells in vitro. Molecular docking studies indicate juncunol as a competitive reversible inhibitor. Our results suggest that Juncus spp. can be sources of bioactive compounds with application in the food industry as cognitive-enhancer nutraceuticals. (C) 2017 Elsevier Ltd. All rights reserved.
  • If you cannot beat them, join them: exploring the fruits of the invasive species Carpobrotus edulis (L.) NE Br as a source of bioactive products
    Publication . Castañeda-Loaiza, Viana; Placines, Chloé; Rodrigues, Maria João; Pereira, Catarina; Zengin, Gokhan; Uysal, Ahmet; Jeko, Jozsef; Cziaky, Zoltan; Reis, Catarina Pinto; Gaspar, Maria Manuela; Custódio, Luísa
    The halophyte species Carpobrotus edulis (L.) N.E. Br, also known as Hottentot-fig, is one of the 20 most aggressive invasive species of coastal areas worldwide. It is native to South Africa, where it is used in traditional medicine for the treatment of several diseases, including tuberculosis and acquired immunodeficiency syndrome (AIDS) caused by the human immunodeficiency virus (HIV). Aiming at a sustainable use of its biomass as a value-added product, this work reports for the first time the in vitro antioxidant, anti-microbial, enzymatic inhibitory properties and toxicity of peel and flesh extracts of Hottentot-fig mature fruits. The extracts' chemical composition was also determined by spectrophotometric methods (total contents of phenolics: TPC; flavonoids: TFC and tannins: TTC), and by high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS/MS). The peels' extracts had generally the highest TPC, TFC and TTC, especially the ethanol ones (TPC: 272.82 mg gallic acid equivalents (GAE)/g dry weight (DW), TFC: 1.58 mg quercetin equivalents (QE)/g DW and TTC: 20.3 mg catechin equivalents (CE)/g DW). The peels' extracts also had the highest diversity of compounds, mostly phenolic acids, flavonoids, and coumarins, as identified by HPLC-ESI-MS/MS. Some molecules were specific to a particular fruit part, for example, coumaric acid and uvaol in the peel, and vanillin and kaempferol-O-(rhamnosyl)hexosylhexoside in the flesh. Some compounds are here described for the first time in Hottentot-fig, such as azelaic acid and emodin. The peel's extracts had the highest anti radical activity, especially the ethanol and acetone towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) (half maximal inhibitory concentration (IC50) values of 0.59 and 0.88 mg/mL, respectively), and the acetone extract against 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) (IC50 = 0.56 mg/mL). Samples had nil capacity to chelate iron, a low copper chelation potential, but a significant capacity to reduce iron, especially the ethanol (IC50 = 0.09 mg/mL) and the acetone extracts of peels (IC50 = 0.10 mg/mL) and flesh (IC50 = 0.11 mg/mL) and also the water peel's extracts (IC50 = 0.18 mg/mL). Samples had nil to low activity towards the enzymes acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), alpha-amylase and alpha-glucosidase, but displayed a strong inhibition of tyrosinase, especially the ethanol peel's extracts (29.55 mg kojic acid equivalents (KAE)/g). Samples had nil to low in vitro toxicity towards human keratinocytes. All together our results suggests possible novel biotechnological applications of Hottentot-fig fruits as sources of innovative bioactive ingredients for the food, cosmetic, agriculture and/or pharmaceutical industries.
  • Biochemical profile and in vitro neuroprotective properties of Carpobrotus edulis L., a medicinal and edible halophyte native to the coast of South Africa
    Publication . Rocha, M. I.; J, Nogueira-Rodrigues; Pereira, C.; Pereira, H.; Silva, Manuela F. G. M.; da Rosa Neng, N.; Nogueira, J. M. F.; Varela, J.; Barreira, Luísa; Custódio,
    This work reports the nutritional profile and in vitro neuroprotective properties of leaves of Carpobrotus edulis L, a medicinal and edible succulent species native to the coast of South Africa. Biomass was evaluated for proximate composition and for contents in carotenoids, liposoluble pigments and minerals. Hexane, dichloromethane, ethyl acetate and methanol extracts were prepared by Soxhlet extraction from dried biomass and evaluated for in vitro inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), capacity to attenuate hydrogen peroxide (H2O2)-induced injury in the human dopaminergic cell line SH-SY5Y and for anti-neuroinflammatory potential on lipopolysaccharide (LPS)-stimulated microglia cells. Extracts were evaluated for antioxidant activity by four complementary methods, total content of phenolics, tannins and flavonoids. Finally the profile of the main phenolic compounds was determined by high performance liquid chromatography with diode array detection (HPLC-DAD). C edulis has a high moisture content, high levels of crude protein, fibre, ash, carotenoids, calcium and iron and a low fat level. The extracts were able to efficiently scavenge the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), reduce iron and chelate copper and iron ions, and exhibited different levels of phenolic compounds in the order ethyl acetate > methanol > dichloromethane > hexane. The main compounds detected were gallic and salicylic acids and quercetin, all in the ethyl acetate extract. The extracts allowed a dual and potent inhibition of AChE and BuChE. The dichloromethane and methanol extracts had the strongest capacity to prevent cell death induced by H2O2, and the methanol extract had anti-neuronflammatory properties. All together our results suggest that consumption of leaves of C edulis can contribute for a balanced diet, and that they may add to the improvement of cognitive functions. It also suggests possible novel biotechnological applications of C. edulis such as source of molecules and/or products for the food and/or pharmaceutical industries. Studies aiming to the isolation and identification of the bioactive compounds are already in progress. (C) 2017 SAAB. Published by Elsevier B.V. All rights reserved.
  • Dietary natural plant extracts can promote growth and modulate oxidative status of Senegalese Sole Postlarvae under standard/challenge conditions
    Publication . Xavier, Maria João; Conceição, Luís E. C.; Valente, Luisa M. P.; Colen, R.; Rodrigues, Andreia C. M.; Rocha, Rui J. M.; L, Custódio; Carballo, Carlos; Manchado, Manuel; Engrola, Sofia
    Plant extracts are known for their high content and diversity of polyphenols, which can improve fish oxidative status. A growth trial with Senegalese sole postlarvae (45 days after hatching) fed with one of four experimental diets—control (CTRL), and supplemented with curcumin (CC), green tea (GT), and grape seed (GS) extracts—was performed to assess if supplementation could improve growth performance and oxidative status. At the end of the growth trial, postlarvae were submitted to a thermal stress to assess their robustness. Sole growth was improved by CC and GS diets when compared to those fed the CTRL. CC and CTRL postlarvae presented the lowest oxidative damage (lipid peroxidation and protein carbonylation values). Stress-related biomarkers (heat shock protein 70 and glutathione-S-transferase) decreased in CC fish compared to those fed the CTRL diet, which might be due to a direct antioxidant capacity. In contrast, oxidative damage increased in GT and GS sole reared in standard conditions. However, after a thermal stress, GT and GS diets prevented the increase of protein carbonylation content and the decrease of antioxidant glutathione, depending on exposure time. Overall, dietary supplementation with natural extracts modulated oxidative status and stress response after a short/long-term exposure to temperature.