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- Efficacy, Stability, and Safety Evaluation of New Polyphenolic Xanthones Towards Identification of Bioactive Compounds to Fight Skin PhotoagingPublication . Resende, Diana I. S. P.; Almeida, Mariana C.; Maciel, Bruna; Carmo, Helena; Lobo, José Sousa; Dal Pozzo, Carlotta; Cravo, Sara M.; Rosa, Gonçalo P.; Kane-Pagès, Aida; Barreto, Maria do Carmo; Almeida, Isabel F.; Sousa, Maria Emília de; Pinto, Madalena M. M.Antioxidants have long been used in the cosmetic industry to prevent skin photoaging, which is mediated by oxidative stress, making the search for new antioxidant compounds highly desirable in this field. Naturally occurring xanthones are polyphenolic compounds that can be found in microorganisms, fungi, lichens, and some higher plants. This class of polyphenols has a privileged scaffold that grants them several biological activities. We have previously identified simple oxygenated xanthones as promising antioxidants and disclosed as hit, 1,2-dihydroxyxanthone (1). Herein, we synthesized and studied the potential of xanthones with different polyoxygenated patterns as skin antiphotoaging ingredients. In the DPPH antioxidant assay, two newly synthesized derivatives showed IC₅₀ values in the same range as ascorbic acid. The synthesized xanthones were discovered to be excellent tyrosinase inhibitors and weak to moderate collagenase and elastase inhibitors but no activity was revealed against hyaluronidase. Their metal-chelating effect (FeCl₃ and CuCl₂) as well as their stability at different pH values were characterized to understand their potential to be used as future cosmetic active agents. Among the synthesized polyoxygenated xanthones, 1,2-dihydroxyxanthone (1) was reinforced as the most promising, exhibiting a dual ability to protect the skin against UV damage by combining antioxidant/metal-chelating properties with UV-filter capacity and revealed to be more stable in the pH range that is close to the pH of the skin. Lastly, the phototoxicity of 1,2-dihydroxyxanthone (1) was evaluated in a human keratinocyte cell line and no phototoxicity was observed in the concentration range tested.
- Kaempferol Derivatives from Hedychium gardnerianum : Unveiling the Potential of an Invasive PlantPublication . Tavares, Wilson R.; Barreto, Maria do Carmo; Seca, Ana M. L.The therapeutic properties of plants and of their secondary metabolites are a current research topic of great interest. Considering that Hedychium species are used in folk medicine around the globe, Hedychium gardnerianum Sheppard ex Ker Gawl., an extremely aggressive invasive plant in Hawaii and in Azores, was selected and phytochemically studied in order to search for natural compounds with interesting biological activities. […].
- Chemical Composition and Phytopharmaceuticals : An Overview of the Caulerpa and Cystoseira GeneraPublication . Rosa, Gonçalo P.; Barreto, Maria do Carmo; Seca, Ana M. L.; Pinto, Diana C. G. A.In recent years, macroalgae attracted increasing attention from many industries of diverse branches such as plastics, cosmetics, pharmaceuticals, and food. This interest is due to the diverse chemical composition existing within the various macroalgae classes, which offer the possibility of finding a wide array of primary and secondary metabolites with exciting properties and great potential for pharmacological applications. Caulerpa spp. and Cystoseira spp. produce a wide array of exciting compounds that have been isolated and showed a broad range of biological activities such as anti-inflammatory, antibiotic, antiprotozoal, antitumor, cytotoxic activities, among others. These compounds present high biomedical potential, constituting natural structures that could serve as scaffolds for designing novel leads for pharmacological purposes. However, Caulerpa and Cystoseira species and their cosmetic potential are still understudied, which shows a great research opportunity.
- Uncharted Source of Medicinal Products : The Case of the Hedychium GenusPublication . Tavares, Wilson R.; Barreto, Maria do Carmo; Seca, Ana M. L.A current research topic of great interest is the study of the therapeutic properties of plants and of their bioactive secondary metabolites. Plants have been used to treat all types of health problems from allergies to cancer, in addition to their use in the perfumery industry and as food. Hedychium species are among those plants used in folk medicine in several countries and several works have been reported to verify if and how effectively these plants exert the effects reported in folk medicine, studying their essential oils, extracts and pure secondary metabolites. Hedychium coronarium and Hedychium spicatum are the most studied species. Interesting compounds have been identified like coronarin D, which possesses antibacterial, antifungal and antitumor activities, as well as isocoronarin D, linalool and villosin that exhibit better cytotoxicity towards tumor cell lines than the reference compounds used, with villosin not affecting the non-tumor cell line. Linalool and α-pinene are the most active compounds found in Hedychium essential oils, while β-pinene is identified as the most widespread compound, being reported in 12 different Hedychium species. Since only some Hedychium species have been investigated, this review hopes to shed some light on the uncharted territory that is the Hedychium genus.
- Valorization of Seaweed Wracks : Inclusion as Additive in Diets for Grass Carp (Ctenopharyngodon idella)Publication . Galindo, Ana; Rodríguez, Covadonga; Reis, Diana B.; Marrero, Manuel; Acosta, Nieves G.; Barreto, Maria do Carmo; Jiménez, Ignacio A.; Urioste, Jaime de; Venuleo, Marianna; Pérez, José A.Macroalgae have been recently described as a potential ingredient for aquafeeds, exerting several physiological benefits. Grass carp (Ctenopharyngodon idella) is a freshwater species, which has been the major fish species produced in the world in the last years. In order to determine the potential use of macroalgal wracks in fish feeding, C. idella juveniles were fed with an extruded commercial diet (CD) or the CD supplemented with 7% of a wind dried-powder (1 mm) from either a multispecific macroalgal wrack (CD + MU7) or a monospecific macroalgal wrack (CD + MO7) obtained from Gran Canaria island (Spain) coasts. After 100 days of feeding, survival, fish weight, and body indexes were determined, and muscle, liver, and digestive tract samples were collected. The total antioxidant capacity of macroalgal wracks was analyzed by assesing the antioxidant defense response and digestive enzymes activity in fish. Finally, muscle proximate composition, lipid classes (LC), and fatty acid (FA) profiles were also studied. Our results suggest that dietary inclusion of macroalgal wracks does not have negative effects on growth, proximate, and lipid composition, antioxidative status, or digestive capacity of C. idella. In fact, both macroalgal wracks caused a general lower fat deposition, and the multispecific wrack enhanced catalase activity in the liver.
- Aqueous and Ethanolic Plant Extracts as Bio-Insecticides : Establishing a Bridge between Raw Scientific Data and Practical RealityPublication . Tavares, Wilson R.; Barreto, Maria do Carmo; Seca, Ana M. L.Global demand for food production is causing pressure to produce faster and bigger crop yields, leading to a rampant use of synthetical pesticides. To combat the nefarious consequences of its uses, a search for effective alternatives began in the last decades and is currently ongoing. Nature is seen as the main source of answers to crop protection problems, supported by several examples of plants/extracts used for this purpose in traditional agriculture. The literature reviewed allowed the identification of 95 plants whose extracts exhibit insecticide activity and can be used as bio-pesticides contributing to sustainable agriculture. The option for ethanol and/or water extracts is more environmentally friendly and resorts to easily accessible solvents, which can be reproduced by farmers themselves. This enables a bridge to be established between raw scientific data and a more practical reality. Azadirachta indica, Capsicum annuum, Nicotiana tabacum and Tagetes erecta are the most researched plants and have the potential to be viable options in the pest management approach. Azadirachta indica showed the most promising results and Brevicoryne brassicae was the most targeted pest species, being tested against the aqueous and/or ethanolic extracts of 23 different plants. Maceration using dried material (usually leaves) is the extraction method preferred by the majority of authors.
- Valorization of Macaronesia Beach-Cast Seaweeds : Secondary Metabolites and Antiaging ActivityPublication . Seca, Ana M. L.; Faustino, Luís M. M.; Viveiros, Mariana Moniz; Rosa, Gonçalo P.; Barreto, Maria do CarmoBeach-cast seaweeds are a seasonal phenomenon consisting of the accumulation of large tons of algae on beaches, which is unpleasant for beach users and affects the tourism industry, mainly because tourists often interpret stranded natural litter as lowering beach quality, especially if the material starts to decompose. These beach casts are always variable mixtures of different species of seagrass and seaweeds. The present work aimed to contribute to the valorisation of this biomass by studying its chemical composition and bioactivities that reveal its potential in the pharmaceutical and/or cosmeceutical industries. […].
- Laurus Azorica Leaves : Sesquiterpene Lactones and Antiaging ActivityPublication . Viveiros, Mariana Moniz; Barreto, Maria do Carmo; Seca, Ana M. L.Plants are a relevant source of biologically active compounds for skin protection. Laurus azorica (Seub.) Franco, an endemic species from Azores, was traditionally used as a disinfectant, and the oil from its berries was used to treat wounds. This species is barely studied concerning its chemical constituents and biological activities. In this study, three sesquiterpene lactones, costunolide, 11,13-dehydrosantonin and reynosin, were isolated for the first time on the hexane fraction of the ethanol extract from Laurus azorica leaves by chromatographic techniques. […].
- A Green and Simple Protocol for Extraction and Application of a Peroxidase-Rich Enzymatic ExtractPublication . Rosa, Gonçalo P.; Barreto, Maria do Carmo; Pinto, Diana C. G. A.; Seca, Ana M. L.Recently there is a great social expectation that scientists should produce more sustainable and environmentally friendly chemical processes. Within this necessity, biocatalysis presents many attractive features because reactions are often performed in water, under mild conditions, the catalyst is biodegradable and can be obtained from renewable raw materials. In this work, we propose a simple, rapid and low-cost method for the preparation and application of an enzymatic extract from turnip root. The protocol described includes (1) the preparation of the enzymatic extract, (2) the procedure for the assessment of the more favorable working parameters (temperature, pH) and (3) the methodology for the application of the extract as the catalyst for biotransformation reactions. We anticipate that the protocol in this research will provide a simple way for obtaining an enzymatic extract which can operate efficiently under mild conditions and can effectively catalyze the biotransformation of simple phenols.
- Bioaccumulation and potential ecotoxicological effects of trace metals along a management intensity gradient in volcanic pasturelandsPublication . Parelho, Carolina Paula Furtado de Medeiros; Rodrigues, Armindo; Barreto, Maria do Carmo; Cruz, José Virgílio; Rasche, Frank; Silva, Luís; Garcia, PatríciaThe particularities of volcanic soils raise the need to better understand the link between soil agricultural management intensity and trace metal bioaccumulation. The Azores are a region characterized by volcanic soils, which were changed in different degrees according to the intensity of the agricultural practices. The main objective of this study was to assess the potential ecotoxicological effects of the trace metals present in volcanic pastureland soils along a gradient of management intensity (i.e., semi-natural, permanent and reseeded), using earthworms (Eisenia fetida) as biological indicators. For this purpose earthworms were exposed during 7, 14, 28 and 56 days to soils from the three types of pastures. At each exposure time, we quantified trace element bioaccumulation (As, Cd, Co, Cr, Cu, Hg, Li, Mn, Mo, Ni, Pb, Rb, U, V and Zn) and the activities of superoxide dismutase and acetylcholinesterase in earthworm tissues. Overall, the results showed that the type of pastureland management significantly increased the soil contents in trace metals: V, Co, Ni and Zn in semi-natural pasturelands; As, Cd and Hg in reseeded pasturelands; and, Rb and U in both permanent and reseeded pasturelands. The soil physicochemical properties observed in the reseeded pastureland systems (higher electric conductivity values associated with a moderately acid pH value) modulated the metal bioavailability, from soil to biota, leading to a greater Hg bioaccumulation in earthworm tissues. The long-term exposure (56 days) of earthworms to reseeded pastureland soil was associated with adverse biological effects (intensification of AChE activity and decrease of SOD activity), encompassing key processes such as neurotransmission and antioxidant defence mechanisms in resident soil biota (earthworms). This study point towards the increased importance of semi-natural and permanent pastureland management, over the intensive management (reseeded pasturelands), in favour of more sustainable ecosystems.
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