Exploring the bioavailability of (poly)phenols from berries and their potential activities in humans

(Poly)phenols are the most widely distributed secondary metabolites, in plants, and, therefore, are regular constituents of human food products. The regular ingestion of (poly)phenol-containing foods has been associated with a reduced risk of acquiring chronic diseases and many studies are currently trying to corroborate this theory. However, the precise contribution of (poly)phenols to disease prevention is still unknown.(...)Fundação para a Ciência e a Tecnologia (FCT

Compostos fenólicos e sua actividade antioxidante em espécies de Juniperus:análise da produção sazonal e sob condições de stresse

Tese de mestrado, Biologia (Biologia Celular e Biotecnologia), 2009, Universidade de Lisboa, Faculdade de CiênciasGrande importância tem sido atribuída a substâncias com forte actividade antioxidante, assumidas como protectoras contra doenças degenerativas e envelhecimento, causados por espécies reactivas de oxigénio. No sentido de identificar as condições que promovem a acumulação foliar de substâncias fenólicas com antioxidante, utilizaram-se plantas das espécies Juniperus turbinata Guss., Juniperus phoenicea L. e Juniperus navicularis Gand., e das subspécies, Juniperus oxycedrus oxycedrus L. e Juniperus oxycedrus badia H. Gay. Para extractos hidroetanólicos destas plantas, determinou-se a variação anual (2008) do conteúdo em compostos fenólicos, por intermédio do método de Folin-Ciocalteau, e de flavonóides, pelo método baseado na complexação com AlCl3. Durante o mesmo período, foi também quantificada a actividade antioxidante dos extractos pelo método de ORAC. Detectou-se uma variação do conteúdo em fenóis/flavonóides ao longo do ano, com especial acumulação nos meses de Novembro e Dezembro. Nestes meses, foram registados os valores mais elevados, 113,5 mg GAE g-1 peso seco (ps) para fenóis totais em J. turbinata, e 63,3 mg CE g-1 ps para flavonóides em J. oxycedrus oxycedrus. Os valores máximos de actividade antioxidante foram registados nos meses de Maio/Junho e Agosto/Setembro, quando J. oxycedrus badia atingiu 3307 µmol TE g-1 ps. Sujeitaram-se, também, plantas dos taxa J. phoenicea, J. turbinata e J. oxycedrus badia, a stresses de seca, de salinidade elevada, de frio e pulverização com metil-jasmonato, no sentido de verificar o seu efeito na acumulação de compostos fenólicos e na actividade antioxidante dos extractos. Destacaram-se o stresse de salinidade elevada, que induziu um aumento dos compostos fenólicos em J. oxycedrus badia, sem contudo aumentar a actividade antioxidante, e a exposição ao metil-jasmonato, que induziu um aumento acentuado dos compostos fenólicos e da actividade antioxidante de extractos de J. phoenicea. De forma a conhecer os ramos da via biossintética dos polifenóis mais activos nas condições de maior acumulação de polifenóis, procedeu-se à quantificação relativa dos transcritos codificantes para algumas enzimas chave na via biossintética dos fenóis, por Real Time Polymerase Chain Reaction (PCR). Constataram-se aumentos relevantes da expressão dos genes codificantes para as enzimas fenilalanina amoníaco liase (PAL), flavanona 3-hidroxilase (F3H), antocianidina sintase (ANS) e antocianidina redutase (ANR) para J. phoenicea sujeito à exposição de metil-jasmonato e das enzimas PAL e ANR para J. oxycedrus badia sujeito a stresse salino.High importance has been given to substances with high antioxidant activity, assumed as protective against reactive oxygen species, which are causers of aging and degenerative diseases. In order to identify which conditions promote foliar accumulation of phenolic compounds with high antioxidant activity, plants belonging to the species Juniperus turbinata Guss., Juniperus phoenicea L. and Juniperus navicularis Gand., and to the subspecies Juniperus oxycedrus oxycedrus L. e Juniperus oxycedrus badia H. Gay were used. Using hydroethanolic extracts, the total phenolic and flavonoid annual (2008) variation was determined, with Folin-Ciocalteau method and the method based on AlCl3 complexation, respectively. During the same period, the extracts antioxidant activity was quantified with the ORAC method. The variation in phenols/flavonoids contents and in the antioxidant activity along the year were recorded. A higher accumulation of total phenolic compounds and flavonoids was observed in November and December. In these months, J. turbinata phenolics content reached 113,5 mg GAE g-1 dry weight (dw), whereas J. oxycedrus oxycedrus flavonoid content reached 63,3 mg CE g-1 dw. The highest values of antioxidant activity were registered in May/June and August/September, with J. oxycedrus badia reaching the highest value, 3306,6 µmol TE g-1 dw. Plants belonging to the taxa, J. phoenicea, J. turbinata and J. oxycedrus badia were exposed to drought, high salinity, and cold stresses, and elicitation with methyl jasmonate, to determine how these conditions affect phenols accumulation and antioxidant activity in the plant extracts. Of these tests, salinity stress induced an increase in phenolic content of J. oxycedrus badia, whereas methyl jasmonate not only increased phenolic content in J. phoenicea extract, but also its antioxidant activity. In order to pinpoint the most active branches of polyphenolic biosynthetic pathway under conditions of higher polyphenol accumulation, the level of transcripts encoding selected major enzymes of phenolic metabolism was assessed by Real Time Polymerase Chain Reaction (PCR). Significant increases in transcripts were observed for the enzymes phenylalanine ammonia-lyase (PAL), flavanone 3-hydroxylase (F3H), anthocyanidin synthase (ANS) e anthocyanidin reductase (ANR) for J. phoenicea exposed to methyl jasmonate, and for the enzymes PAL and ANR for J. oxycedrus badia subjected to salt stress

Glutamine and cystine-enriched diets modulate aquaporins gene expression in the small intestine of piglets

Research Areas: Science & Technology ; Other TopicsABSTRACT - The regulation of glycerol permeability in the gastrointestinal tract is crucial to control fat deposition, lipolysis and gluconeogenesis. Knowing that the amino acid glutamine is a physiological regulator of gluconeogenesis, whereas cystine promotes adiposity, herein we investigated the effects of dietary supplementation with glutamine and cystine on the serum biochemical parameters of piglets fed on amino acid-enriched diets, as well as on the transcriptional profile of membrane water and glycerol channels aquaporins (AQPs) in the ileum portion of the small intestine and its impact on intestinal permeability. Twenty male piglets with an initial body weight of 8.8 ± 0.89 kg were allocated to four dietary treatments (n = 5) and received, during a four week-period, a basal diet without supplementation (control) or supplemented with 8 kg/ton of glutamine (Gln), cystine (Cys) or the combination of the two amino acids in equal proportions (Gln + Cys). Most biochemical parameters were found improved in piglets fed Gln and Cys diet. mRNA levels of AQP3 were found predominant over the others. Both amino acids, individually or combined, were responsible for a consistent downregulation of AQP1, AQP7 and AQP10, without impacting on water permeability. Conversely, Cys enriched diet upregulated AQP3 enhancing basolateral membranes glycerol permeability and downregulating glycerol kinase (GK) of intestinal cells. Altogether, our data reveal that amino acids dietary supplementation can modulate intestinal AQPs expression and unveil AQP3 as a promising target for adipogenesis regulation.info:eu-repo/semantics/publishedVersio

Chemical characterization and bioactivity of phytochemicals from Iberian endemic Santolina semidentata and strategies for ex situ propagation

Asteraceae family members are well-known for their medicinal potential, comprising several properties that make them unique among plants. Here we focus on Santolina semidentata, an endemic plant from the Iberian Peninsula, not yet described for its medicinal properties. Phytochemical characterization of S. semidentata was performed, concerning total phenol content, flavonoid content, antioxidant capacity, HPLC-DAD profile, acetylcholinesterase inhibitory capacity, cytotoxicity and neuroprotective effect in a human neurodegeneration cell model. Moreover, essential oil composition and antifungal activity were also analised. This oil might be useful for therapeutical purposes, particularly in the treatment of dermatophytosis. S. semidentata potential for neuroprotection was revealed by acetylcholinesterase inhibitory capacity and also by an effective protective effect in human neuronal cells. Furthermore, different seed conservation protocols, as well as successful in vitro propagation were established which may be useful when integrated in a broad strategy for the conservation of these endemic plants and their sustainable use for potential biotechnological applications. The results presented here greatly contribute to value this species regarding its potential as a source of phytochemicals with prospective neuroprotective health benefits, either as alternative neuroprotective drugs or as leads for synthetizing more effective molecules.The authors wish to thank to “Fundo EDP para a Biodiversidade” for financial support. This work was also supported by “Fundação para a Ciência e a Tecnologia” through grant PEst-OE/EQB/LA0004/2011, BGCT/33418/2008, Green-it: UID/Multi/04551/2013, iNOVA4Health: UID/Multi/04462/2013 and financial support to CNS (IF/01097/20132), RP (SFRH/BD/63615/2009), IF (SFRH/BD/86584/2012) and AG (SFRH/BD/103155/2014).info:eu-repo/semantics/publishedVersio

Glutamine and cystine-enriched diets modulate aquaporins gene expression in the small intestine of piglets

Research ArticleThe regulation of glycerol permeability in the gastrointestinal tract is crucial to control fat deposition, lipolysis and gluconeogenesis. Knowing that the amino acid glutamine is a physiological regulator of gluconeogenesis, whereas cystine promotes adiposity, herein we investigated the effects of dietary supplementation with glutamine and cystine on the serum biochemical parameters of piglets fed on amino acid-enriched diets, as well as on the transcriptional profile of membrane water and glycerol channels aquaporins (AQPs) in the ileum portion of the small intestine and its impact on intestinal permeability. Twenty male piglets with an initial body weight of 8.8 ± 0.89 kg were allocated to four dietary treatments (n = 5) and received, during a four week-period, a basal diet without supplementation (control) or supplemented with 8 kg/ton of glutamine (Gln), cystine (Cys) or the combination of the two amino acids in equal proportions (Gln + Cys). Most biochemical parameters were found improved in piglets fed Gln and Cys diet. mRNA levels of AQP3 were found predominant over the others. Both amino acids, individually or combined, were responsible for a consistent downregulation of AQP1, AQP7 and AQP10, without impacting on water permeability. Conversely, Cys enriched diet upregulated AQP3 enhancing basolateral membranes glycerol permeability and downregulating glycerol kinase (GK) of intestinal cells. Altogether, our data reveal that amino acids dietary supplementation can modulate intestinal AQPs expression and unveil AQP3 as a promising target for adipogenesis regulationinfo:eu-repo/semantics/publishedVersio

Analysis of Phenolic Compounds in Portuguese Wild and Commercial Berries after Multienzyme Hydrolysis

Berry fruits are a good source of phenolic compounds and thus, potentially beneficial to health. Phenolic compounds are mainly present as a variety of conjugated forms, either with sugars via O-glycosidic bonds or with other polyols as esters. This chemodiversity makes characterization and identification highly demanding. Selected varieties of commercial blueberries, raspberries and blackberries and the two wild berries Portuguese crowberry and strawberry tree fruits were characterized for individual phenolic content by liquid chromatography–diode array detection and mass spectrometry (HPLC-DAD-MS) after hydrolysis by a novel combination of the fungal glycosidases hesperidinase and cellulase. This approach is shown to be a simple alternative to other existing methods for analysis of plant phenolic compound aglycones. The hydrolysis of glycosides and organic acid esters is efficient and less aggressive than acid and alkaline hydrolysis. This method is able to disclose new sources of dietary phenolic compounds, and the potential usefulness of Portuguese crowberry and strawberry tree fruit is herein demonstrated

Phenolic sulfates as new and highly abundant metabolites in human plasma after ingestion of a mixed berry fruit purée

Bioavailability studies are vital to assess the potential impact of bioactive compounds on human health. Although conjugated phenolic metabolites derived from colonic metabolism have been identified in the urine, the quantification and appearance of these compounds in plasma is less well studied. In this regard, it is important to further assess their potential biological activity in vivo. To address this gap, a cross-over intervention study with a mixed fruit purée (blueberry, blackberry, raspberry, strawberry tree fruit and Portuguese crowberry) and a standard polyphenol-free meal was conducted in thirteen volunteers (ten females and three males), who received each test meal once, and plasma metabolites were identified by HPLC–MS/MS. Sulfated compounds were chemically synthesised and used as standards to facilitate quantification. Gallic and caffeic acid conjugates were absorbed rapidly, reaching a maximum concentration between 1 and 2 h. The concentrations of sulfated metabolites resulting from the colonic degradation of more complex polyphenols increased in plasma from 4 h, and pyrogallol sulfate and catechol sulfate reached concentrations ranging from 5 to 20 μm at 6 h. In conclusion, phenolic sulfates reached high concentrations in plasma, as opposed to their undetected parent compounds. These compounds have potential use as biomarkers of polyphenol intake, and their biological activities need to be considered

The use of serological tests for detecting HIV infection in general clinical consultations and hospital consultations

To determine the number and type of HIV tests requested in general practice (GP) and in hospital outpatient clinics, to identify principle risk behaviors, to determine the percentage of HIV positive tests and to identify possible factors associated with the request of HIV tests. METHODS: Cross-sectional, analytical and observational study, involving 80 GPs and 45 hospital specialists in the region of Lisbon. All requests for HIV tests were analysed during a 12 month period. RESULTS: 936 HIV tests were requested, with a mean of 12.47 in GP and 0.69 in the hospital. Risk behaviors observed were mainly heterosexual contacts and intravenous drug abuse (IVDA). The motives of the requests mainly were pregnancy, risk behaviors in GP and the presence of symptoms suggesting HIV infection in the hospital. The initiative of the request came from doctors in 70% of the cases. The percentage of HIV positive tests (ELISA + Western blot) was 4.2% in GP and 32% in the hospital. According to risk behaviors, the percentage of seropositivity was 33% in homo/bisexuals, 13% in IVDA, 7% in heterosexuals with risk behaviors and 0.2% in individuals with unidentified risk behaviors. CONCLUSIONS: The patterns of request of HIV tests differ in hospital and in GP. In a significant percentage of cases, no informed consent was obtained prior to HIV testing, both in hospital and GP. This study may serve as an indicator of the need for information and education programs concerning HIV testing directed to health professionals and the general population.Objectivos: Determinar o numero e o tipo de testes serológicos para o VIH solicitados em consultas de clinica geral e em consultas hospitalares, identificar os principais comportamentos de risco, determinar a percentagem de seropositividade para o VIR e identificar possíveis factores associados ao pedido dos testes. Métodos: Estudo de observação, transversal e analítico, com a participação de 80 clínicos gerais e 45 especialistas hospitalares. Foram analisados todos os pedi dos de testes serológicos para o VIR feitos durante 1 ano. Resultados: Foram pedidos 936 testes para o VIR, sendo a media por medico de 12,47 na clinica geral e 0,69 no hospital. Os comporta mentos de risco mais vezes observados foram os contactos heterossexuais de risco e a toxicodependência. Os principais motivos de pedido foram a gravidez e a existência de comportamentos de risco na clinica geral e a suspeita de infecção VIH no hospital. A iniciativa do pedido partiu do medico em mais de 70% dos casos. Numa percentagem significativa de casos os testes foram pedidos numa fase em que poderia não ter ocorrido ainda a seropositivação. A percentagem de seropositivos para o VIR (ELISA Westernblot) foi de 4,2% nas consultas de clinica geral e 32% no hospital. A percentagem de seropositividade foi de 33% nos homo/bissexuais, 13% nos toxico dependentes, 7% nos heterossexuais com comportamento sexual de risco e 0,2% nos indivíduos sem factores de risco. Conclusões: Os padrões de pedido dos testes serológicos para o VIR são significativamente diferentes a nível da clinica geral e do hospital. Parecem verificar-se algumas atitudes menos adequadas por parte dos médicos, nomeadamente a ausência de consentimento esclarecido dos doentes antes da realização dos testes, numa percentagem significativa de casos. Estudos deste tipo podem constituir indicadores importantes da percepção do risco de infecção pelo VIR por parte da população em geral e dos próprios profissionais de saúde, permitindo avaliar da necessidade de determinados programas de intervenção, nomeadamente campanhas de informação e formação