Browsing by Author "Alves-Silva, Jorge M."
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- Antioxidant capacities of flavones and benefits in oxidative-stress related diseasesPublication . Catarino, Marcelo D.; Alves-Silva, Jorge M.; Pereira, Olívia R.; Cardoso, Susana M.Flavonoids, a group of secondary metabolites widely distributed in the plant kingdom, have been acknowledged for their interesting medicinal properties. Among them, natural flavones, as well as some of their synthetic derivatives, have been shown to exhibit several biological activities, including antioxidant, anti-inflammatory, antitumor, anti-allergic, neuroprotective, cardioprotective and antimicrobial. The antioxidant properties of flavones allow them to demonstrate potential application as preventive and attenuating agents in oxidative stress, i.e., a biological condition that is closely associated to aging process and several diseases. Some flavones interfere in distinct oxidative-stress related events by directly reducing the levels of intracellular free radicals (hydroxyl, superoxide and nitric oxide) and/or of reactive species (e.g. hydrogen peroxide, peroxynitrite and hypochlorous acid) thus preventing their amplification and the consequent damage of other biomolecules such as lipids, proteins and DNA. Flavones can also hinder the activity of central free radical-producing enzymes, such as xanthine oxidase and nicotinamide adenine dinucleotide phosphate oxidase (NADPH-oxidase) or inducible nitric oxide synthase (iNOS) and can even modulate the intracellular levels of pro-oxidant and/or antioxidant enzymes. The evaluation of flavones antioxidant ability has been extensively determined in chemical or biological in vitro models, but in vivo therapy with individual flavones or with flavones-enriched extracts has also been reported. The present manuscript revises relevant studies focusing the preventive effects of flavones on stress-related diseases, namely the neurological and cardiovascular diseases, and diabetes and its associated complications.
- Beneficial effects of Salvia plants: correlation with bioactive componentsPublication . Afonso, Andrea Luísa Fernandes; Alves-Silva, Jorge M.; Pereira, Olívia R.; Cardoso, Susana M.Plants of the genus Salvia, also known as sage, are distributed worldwide and are commonly used for distinct purposes in culinary, cosmetic and fragrance industry, as well as in traditional medicine. Scientific data supporting the health-beneficial properties of sage have been obtained in chemical and biological (in vitro and in vivo) models, mostly using phenolicenriched extracts and essential oils and/or their purified constituents. Phenolic compounds in sage mainly comprise caffeic acid derivatives depsides together with glycosidic derivatives of the flavones luteolin and apigenin. In turn, essential oils are enriched in monoterpenes and their oxygenated derivatives (e.g a-/B-pinene, 1,8-cineole, a-/B-thujone and linalool). This chapter reviews the antioxidant, anti-inflammatory, antitumor, neuroprotective and cardioprotective potential benefits of Salvia plants, as well as the correlation to its bioactive components.
- Chromatography as a tool for identification of bioactive compounds in honeybee products of botanical originPublication . Catarino, Marcelo D.; Alves-Silva, Jorge M.; Falcão, Soraia; Vilas-Boas, Miguel; Jordão, M.; Cardoso, Susana M.Honey, propolis, and pollen are three important components of the beehive produced by honeybees mixing different plant parts (nectar, resin and pollen) with their own secretions, for further usage with different purposes in the hive. The fact that these natural products have been associated with numerous health benefits has attracted the attention of researchers resulting in a significant raise of scientific studies attesting their biological properties. Among the various constituents of honey, propolis and pollen, the phenolic compounds are the ones most frequently related to the beneficial properties of these products and hence, one of the main investigated groups. Their characterization is important to understand individual contribution(s) and synergistic effects of each compound for the overall biological effects of the bee product. To pursuit this goal, spectrophotometric techniques including HPLC, GC and TLC, alongside with the respective detection methods such as DAD, FLD and MS, have been developed and improved in order to offer better and more accurate separative performances. The aim of this review is to give an approach on the course that the chromatographic techniques have taken until the most recent trends on this field applied to the separation and characterization of the phenolic constituents of honey, propolis and bee pollen as well as an overall perspective of variability in terms of phenolic composition that can be found in the three bee products mentioned.
- Mediterranean diet: a precious tool for fighting inflammatory diseasesPublication . Catarino, Marcelo D.; Alves-Silva, Jorge M.; Pereira, Olívia R.; Cardoso, Susana M.Epidemiological studies indicate that populations who consume foods rich in specific polyphenols have lower incidence of inflammatory diseases. In turn, Mediterranean diet, claimed for its several health benefits, provides a wide range of foods which are particularly enriched sources of polyphenols, some of which known for their anti-inflammatory properties. In this context, various herbs, vegetables and fruits, as well as fruit derivative products, such as wine and virgin olive oil, are believed to have an important role preventing and/or ameliorating inflammatory conditions through diet. Additionally, they are strong candidates for anti-inflammatory drugs. In general, the anti-inflammatory properties of polyphenols involve the modulation of pro-inflammatory gene expression including cyclooxygenase, lipoxygenase, nitric oxide synthases and several pivotal cytokines such as TNF-α, interleukin-1 (IL-1) and interleukin-6 (IL-6), mainly by acting through nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling. Since inflammation is a phenomenon present in many chronic diseases including cancer, diabetes, obesity, and cardiovascular disease, the modulation of the aforementioned markers by polyphenols may positively contribute for the prevention and/or amelioration of these diseases. The present chapter focus various edible Mediterranean typical foods known for their anti-inflammatory properties, as well as the main pheno-lic constituents associated to the protection process and their underlying mechanisms of action.