72 research outputs found
Dose-dependent protective and inductive effects of xanthohumol on oxidative DNA damage in Saccharomyces cerevisiae
The effect of xanthohumol, a prenylflavonoid isolated from the hop plant (Humulus lupulus L.), on Saccharomyces cerevisiae DNA oxidative damage and viability was evaluated. Yeast cultures under oxidative stress, induced by H2O2, displayed stronger growth in the presence of 5 mg/L of xanthohumol than cultures with only H2O2. Likewise, DNA damage assessed by the comet assay was significantly lower in cells co-incubated with xanthohu- mol and H2O2. Accordingly, fluorescence of dichlorofluorescein in cells treated with H2O2 and xanthohumol was considerably lower than in cells exclusively treated with H2O2, in- dicative of a reactive oxygen species scavenging mechanism and consequent formation of oxidation products, as detected by mass spectrometry. However, at concentrations above 5 mg/L, xanthohumol elicited an opposite effect, leading to a slower growth rate and signifi- cant increase in DNA damage. A yeast yap1 deletion mutant strain sensitive to oxidative stress grew more slowly in the presence of at least 5 mg/L of xanthohumol than cultures of the wild type, suggesting that xanthohumol toxicity is mediated by oxidative stress. This evidence provides further insight into the impact of xanthohumol on yeast cells, support- ing dose-dependent antioxidant/antigenotoxic and prooxidant/genotoxic effects.This work was funded by FEDER through the Operational
Programme for Competitiveness Factors – COMPETE
and by National Funds through FCT – Foundation
for Science and Technology, under the projects UID/
QUI/50006/2013 and NORTE-07-0124-FEDER-000069. DC
wishes to acknowledge FCT for his PhD studentship
(SFRH/BD/79939/2011). BJ acknowledges the support of
FCT through project PTDC/AAC-AMB/120940/2010 'MYCOFAT'.
DC wishes to acknowledge FCT for his PhD studentship
(SFRH/BD/79939/2011). We thank Martin Biendl,
from Hopsteiner (New York, NY, USA), for donating the
xanthohumol and Cristina Ribeiro for help in fl ow cytometry
analyses. Mass spectrometry analyses were conducted
at CEMUP (Materials Centre of the University of
Porto, Portugal).info:eu-repo/semantics/publishedVersio
Antiangiogenic and antioxidant in vitro properties of hydroethanolic extract from açaí (Euterpe oleracea) dietary powder supplement
The Euterpe oleracea fruit (açaí) is a promising source of polyphenols with health-promoting properties. To our knowledge, few studies have focused on the influence of açaí phytochemicals on angiogenesis, with a significant impact on cancer. This study aimed at investigating the phytochemical profile of a purple açaí hydroethanolic extract (AHE) obtained from a commercial dietary powder supplement by high-performance liquid chromatography coupled to diode array detection and electrospray ionization mass spectrometry, and evaluate its in vitro effects on distinct angiogenic steps during vessel growth and on oxidative markers in human microvascular endothelial cells (HMEC-1). The phenolic profile of AHE revealed the presence of significant levels of anthocyanins, mainly cyanidin-3-O-rutinoside, and other flavonoids with promising health effects. The in vitro studies demonstrated that AHE exerts antiangiogenic activity with no cytotoxic effect. The AHE was able to decrease HMEC-1 migration and invasion potential, as well as to inhibit the formation of capillary-like structures. Additionally, AHE increased antioxidant defenses by upregulating superoxide dismutase and catalase enzymatic activities, accompanied by a reduction in the production of reactive oxygen species. These data bring new insights into the potential application of angiogenic inhibitors present in AHE on the development of novel therapeutic approaches for angiogenesis-dependent diseases.info:eu-repo/semantics/publishedVersio
Brewer’s spent grains protects against oxidative DNA damage in Saccharomyces cerevisiae
Brewer’s spent grain (BSG), obtained from barley malt during brewing, contains high amounts of phenolic acids, predominantly ferulic and p-coumaric acids. The protective effects of BSG extracts against oxidative DNA damage induced by H2O2 in Saccharomyces cerevisiae cells were investigated using an optimized yeast comet assay and flow cytometry. The results indicated that BSG extracts from black malt exhibited a 5-fold reduction in the genotoxic effects of H2O2, compared to the 2-fold decrease by the BSG extracts from pilsen malts. Flow cytometry analysis with dichlorofluorescein diacetate demonstrated that the intracellular oxidation of S. cerevisiae is also reduced to approximately 50% in the presence of 20-fold diluted BSG extracts. BSG extracts obtained from pilsen and black malt types exert dose-dependent protective properties against the genotoxic effects induced by ROS and decrease intracellular oxidation of yeast cells.This work received financial support from the European Union (FEDER Funds through COMPETE) and
National Funds (FCT, Fundação para a Ciência e a Tecnologia) through project Pest-C/EQB/LA0006/2013 and
PEst-C/BIA/UI4050/2011. The work also received financial support from the European Union (FEDER funds)
under the framework of QREN through Project NORTE-07-0124-FEDER-000069. DOC receives a postdoc
grant through the project Operação Norte-01-0145-FEDER-000011. MMM wishes to acknowledge to FCT for
her postdoctoral grant (SFRH/BPD/97049/2013). The authors also thank Unicer – Bebidas de Portugal, S. A. for
the supply of BSG samples.info:eu-repo/semantics/publishedVersio
Brewer's spent grain from different types of malt: Evaluation of the antioxidant activity and identification of the major phenolic compounds
The antioxidant activity and phenolic composition of brewer's spent grain (BSG) extracts obtained by
microwave-assisted extraction from twomalt types (light and darkmalts) were investigated. The total phenolic
content (TPC) and antioxidant activity among the light BSG extracts (pilsen, melano, melano 80 and carared)were
significantly different (p b 0.05) compared to dark extracts (chocolate and black types), with the pilsen BSG
showing higher TPC (20 ± 1 mgGAE/g dry BSG). In addition, the antioxidant activity assessed by 2,2-diphenyl-
1-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and deoxyribose assays decreased as
a result of increasing kilning temperatures in the following order: pilsen N melano N melano 80 N carared N
chocolate N black. HPLC-DAD/ESI-MS/MS analysis indicated the presence of phenolic acids, such as ferulic,
p-coumaric and syringic acids, as well as several isomeric ferulate dehydrodimers and one dehydrotrimer. Chocolate
and black extracts, obtained frommalts submitted to the highest kilning temperatures, showed the lowest levels of
ferulic and p-coumaric acids. These results suggested that BSG extracts from pilsen malt might be used as an
inexpensive and good natural source of antioxidants with potential interest for the food, pharmaceutical and/or
cosmetic industries after purification
Simultaneous inhibition of pan-phosphatidylinositol-3-kinases and MEK as a potential therapeutic strategy in peripheral T-cell lymphomas
Obtained from Haematologica/the Hematology Journal website http://www.haematologica.orgPeripheral T-cell lymphomas are very aggressive hematologic malignancies for which there is no targeted therapy.
New, rational approaches are necessary to improve the very poor outcome in these patients. Phosphatidylinositol-
3-kinase is one of the most important pathways in cell survival and proliferation. We hypothesized that phosphatidylinositol-
3-kinase inhibitors could be rationally selected drugs for treating peripheral T-cell lymphomas.
Several phosphatidylinositol-3-kinase isoforms were inhibited genetically (using small interfering RNA) and pharmacologically
(with CAL-101 and GDC-0941 compounds) in a panel of six peripheral and cutaneous T-cell lymphoma
cell lines. Cell viability was measured by intracellular ATP content; apoptosis and cell cycle changes were
checked by flow cytometry. Pharmacodynamic biomarkers were assessed by western blot. The PIK3CD gene,
which encodes the δ isoform of phosphatidylinositol-3-kinase, was overexpressed in cell lines and primary samples,
and correlated with survival pathways. However, neither genetic nor specific pharmacological inhibition of
phosphatidylinositol-3-kinase δ affected cell survival. In contrast, the pan-phosphatidylinositol-3-kinase inhibitor
GDC-0941 arrested all T-cell lymphoma cell lines in the G1 phase and induced apoptosis in a subset of them. We
identified phospho-GSK3b and phospho-p70S6K as potential biomarkers of phosphatidylinositol-3-kinase
inhibitors. Interestingly, an increase in ERK phosphorylation was observed in some GDC-0941-treated T-cell lymphoma
cell lines, suggesting the presence of a combination of phosphatidylinositol-3-kinase and MEK inhibitors.
A highly synergistic effect was found between the two inhibitors, with the combination enhancing cell cycle arrest
at G0/G1 in all T-cell lymphoma cell lines, and reducing cell viability in primary tumor T cells ex vivo. These results
suggest that the combined treatment of pan-phosphatidylinositol-3-kinase + MEK inhibitors could be more effective
than single phosphatidylinositol-3-kinase inhibitor treatment, and therefore, that this combination could be
of therapeutic value for treating peripheral and cutaneous T-cell lymphomas.This work was supported by grants from the Asociación Española
Contra el Cáncer, Fondo de Investigaciones Sanitarias (PI051623,
PI052800 and PI080856), RTICC (RD06/0020/0107) and
Ministerio de Ciencia e Innovación (SAF2008-0387-1). EMS is
supported by a grant from the Department of Education,
Universities and Research of the Basque Government (BFI08.207).
MSB is supported by a Contract Miguel Servet from Fondo de
Investigaciones Sanitarias (CP11/00018
Brewer's spent grain from different types of malt: Evaluation of the antioxidant activity and identification of the major phenolic compounds
The antioxidant activity and phenolic composition of brewer's spent grain (BSG) extracts obtained by
microwave-assisted extraction from twomalt types (light and darkmalts) were investigated. The total phenolic
content (TPC) and antioxidant activity among the light BSG extracts (pilsen, melano, melano 80 and carared)were
significantly different (p b 0.05) compared to dark extracts (chocolate and black types), with the pilsen BSG
showing higher TPC (20 ± 1 mgGAE/g dry BSG). In addition, the antioxidant activity assessed by 2,2-diphenyl-
1-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and deoxyribose assays decreased as
a result of increasing kilning temperatures in the following order: pilsen N melano N melano 80 N carared N
chocolate N black. HPLC-DAD/ESI-MS/MS analysis indicated the presence of phenolic acids, such as ferulic,
p-coumaric and syringic acids, as well as several isomeric ferulate dehydrodimers and one dehydrotrimer. Chocolate
and black extracts, obtained frommalts submitted to the highest kilning temperatures, showed the lowest levels of
ferulic and p-coumaric acids. These results suggested that BSG extracts from pilsen malt might be used as an
inexpensive and good natural source of antioxidants with potential interest for the food, pharmaceutical and/or
cosmetic industries after purification
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.
Location: Amazonia.
Taxon: Angiosperms (Magnoliids; Monocots; Eudicots).
Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.
Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.
Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
Mapping density, diversity and species-richness of the Amazon tree flora
Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution
A novel application of microwave-assisted extraction of polyphenols from brewer’s spent grain with HPLC-DAD-MS analysis
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