RESUMO
In recent years, scientists have become aware that human microbiota, in general, and gut microbiota, in particular, play a major role in human health and diseases, such as obesity and diabetes, among others. A large number of evidence has come to light regarding the beneficial effects, either for the host or the gut microbiota, of some foods and food ingredients or biochemical compounds. Among these, the most promising seem to be polysaccharides (PS) or their derivatives, and they include the dietary fibers. Some of these PS can be found in seaweeds and microalgae, some being soluble fibers, such as alginates, fucoidans, carrageenans and exopolysaccharides, that are not fermented, at least not completely, by colonic microbiota. This review gives an overview of the importance of the dietary fibers, as well as the benefits of prebiotics, to human health. The potential of the PS from marine macro- and microalgae to act as prebiotics is discussed, and the different techniques to obtain oligosaccharides from PS are presented. The mechanisms of the benefits of fiber, in general, and the types and benefits of algal fibers in human health are highlighted. The findings of some recent studies that present the potential effects of prebiotics on animal models of algal biomass and their extracts, as well as oligo- and polysaccharides, are presented. In the future, the possibility of using prebiotics to modulate the microbiome, and, consequently, prevent certain human diseases is foreseen.
Assuntos
Microalgas/química , Prebióticos/administração & dosagem , Alga Marinha/química , Animais , Fibras na Dieta/administração & dosagem , Microbioma Gastrointestinal/fisiologia , Humanos , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologiaRESUMO
Epidemiological studies have shown a relation between antioxidants and the prevention of several chronic diseases. Microalgae are a potential novel source of bioactive molecules, including a wide range of different carotenoids that can be used as nutraceuticals, food supplements and novel food products. The objective of this review is (i) to update the research that has been carried out on the most known carotenoids produced by marine microalgae, including reporting on their high potentialities to produce other less known important compounds; (ii) to compile the work that has been done in order to establish some relationship between carotenoids and oxidative protection and treatment; (iii) to summarize the association of oxidative stress and the various reactive species including free radicals with several human diseases; and (iv) to provide evidence of the potential of carotenoids from marine microalgae to be used as therapeutics to treat or prevent these oxidative stress-related diseases.
Assuntos
Carotenoides/farmacologia , Carotenoides/uso terapêutico , Doença Crônica/prevenção & controle , Microalgas/metabolismo , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Produtos Biológicos/metabolismo , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Carotenoides/metabolismo , Humanos , Estresse Oxidativo/efeitos dos fármacosRESUMO
This review focuses on and discusses the primary phytochemicals present in microalgal biomass - carotenoids, phenolic compounds, antioxidant vitamins, sterols, and polyunsaturated fatty acids - and also on the exopolysaccharides, which are produced by some types of microalgae and may play a significant role in the prevention of cardiovascular diseases (CVD) and strokes. We have listed several preclinical trials and clinical studies supporting the health benefits that most of these compounds may provide. Microalgae are very easy to grow and are not vulnerable to contaminants when grown under controlled conditions. Proper handling and growth conditions may improve the production of phytochemicals. Therefore, they may represent an excellent source of nutraceuticals and food supplements once their safety as a food supplement has been confirmed.
Assuntos
Anti-Inflamatórios/química , Antioxidantes/química , Doenças Cardiovasculares/prevenção & controle , Suplementos Nutricionais , Microalgas/química , Acidente Vascular Cerebral/prevenção & controle , Animais , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/uso terapêutico , Antioxidantes/isolamento & purificação , Antioxidantes/uso terapêutico , Suplementos Nutricionais/análise , Humanos , Microalgas/crescimento & desenvolvimentoRESUMO
AIMS: The influence of two culture media and three different concentrations of sulphate in the medium on the growth of two strains of Porphyridium cruentum and on the production, composition and viscoelastic characteristics, and antimicrobial properties of the sulphated exopolysaccharide (EPS) were studied. MAIN METHODS: A Bohlin C50 rheometer was used to evaluate the viscosity and elasticity of the EPS solutions. HSV virus, types 1 and 2, Vaccinia virus and Vesicular stomatitis virus were used along with two Gram-negative (Escherichia coli and Salmonella enteritidis) and one Gram-positive (Staphylococcus aureus) bacteria, for testing the antimicrobial activity of EPS. KEY-FINDINGS: The growth of microalgae was higher in NTIP medium and the production of EPS was enhanced by sulphate 21mM. The protein content of the EPS was enhanced by the addition of sulphate 52mM and 104mM; this concentration also induced an increase in sulphate content of the EPS. However, neither the contents of EPS in carbohydrates and uronic acids were affected by the culture medium supplementation in sulphate. In general, the EPS from the Spanish strain presented a higher antiviral activity than the EPS from the Israeli strain. All EPS extracts revealed a strong activity against V. stomatitis virus, higher than the activity of all chemical compounds tested. The EPS from the Israeli strain also presented antibacterial activity against S. enteritidis. SIGNIFICANCE: Enrichment of the culture medium with sulphate improved protein and sulphate content of EPS. EPS extracts presented a relevant activity against V. stomatitis virus and S. enteritidis bacterium.
Assuntos
Antibacterianos/química , Antivirais/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Porphyridium/química , Sulfatos/química , Antibacterianos/isolamento & purificação , Antivirais/isolamento & purificação , Antivirais/farmacologia , Meios de Cultura/química , Elasticidade/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/isolamento & purificação , Porphyridium/crescimento & desenvolvimento , Viscosidade/efeitos dos fármacosRESUMO
Marine microalgae and cyanobacteria are very rich in several chemical compounds and, therefore, they may be used in several biological applications related with health benefits, among others. This review brings the research up-to-date on the bioactive compounds produced by marine unicellular algae, directly or indirectly related to human health. It covers and goes through the most studied applications of substances such as PUFA, sterols, proteins and enzymes, vitamins and pigments, in areas so diverse as human and animal nutrition, therapeutics, and aquaculture. The great potential of marine microalgae and the biocoumpounds they produce are discussed in this review.