Impact of increasing fruit and vegetables and flavonoid intake on the human gut microbiota

Epidemiological studies have shown protective effects of fruits and vegetables (F&V) in lowering the risk of developing cardiovascular diseases (CVD) and cancers. Plant-derived dietary fibre (non-digestible polysaccharides) and/or flavonoids may mediate the observed protective effects particularly through their interaction with the gut microbiota. The aim of this study was to assess the impact of fruit and vegetable (F&V) intake on gut microbiota, with an emphasis on the role of flavonoids, and further to explore relationships between microbiota and factors associated with CVD risk. In the study, a parallel design with 3 study groups, participants in the two intervention groups representing high-flavonoid (HF) and low flavonoid (LF) intakes were asked to increase their daily F&V intake by 2, 4 and 6 portions for a duration of 6 weeks each, while a third (control) group continued with their habitual diet. Faecal samples were collected at baseline and after each dose from 122 subjects. Faecal bacteria enumeration was performed by fluorescence in situ hybridisation (FISH). Correlations of dietary components, flavonoid intake and markers of CVD with bacterial numbers were also performed. A significant dose X treatment interaction was only found for Clostidium leptum-Ruminococcus bromii/flavefaciens with a significant increase after intake of 6 additional portions in the LF group. Correlation analysis of the data from all 122 subjects independent from dietary intervention indicated an inhibitory role of F&V intake, flavonoid content and sugars against the growth of potentially pathogenic clostridia. Additionally, we observed associations between certain bacterial populations and CVD risk factors including plasma TNF-α, plasma lipids and BMI/waist circumference.

Urinary metabolomic profiling to identify biomarkers of a flavonoid-rich and flavonoid-poor fruits and vegetables diet: the FLAVURS trial in adults: the FLAVURS trial

The present study aims to investigate the dose dependent effects of consuming diets enriched in flavonoid-rich and flavonoid-poor fruits and vegetables on the urine metabolome of adults who had a C1.5 fold increased risk of cardiovascular diseases. A single-blind, dose-dependent, parallel randomized controlled dietary intervention was conducted where volunteers (n = 126) were randomly assigned to one of three diets: high flavonoid diet, low flavonoid diet or habitual diet as a control for 18 weeks. High resolution LC– MS untargeted metabolomics with minimal sample cleanup was performed using an Orbitrap mass spectrometer. Putative biomarkers which characterize diets with high and low flavonoid content were selected by state-of-the-art data analysis strategies and identified by HR-MS and HR-MS/MS assays. Discrimination between diets was observed by application of two linear mixedmodels: one including a diet-time interaction effect and the second containing only a time effect. Valerolactones, phenolic acids and their derivatives were among sixteen biomarkers related to the high flavonoid dietary exposure. Four biomarkers related to the low flavonoid diet belonged to the family of phenolic acids. For the first time abscisic acid glucuronide was reported as a biomarker after a dietary intake, however its origins have to be examined by future hypothesis driven experiments using a more targeted approach. This metabolomic analysis has identified a number of dose dependent urinary biomarkers (i.e. proline betaine or iberin-N-acetyl cysteine), which can be used in future observation and intervention studies to assess flavonoids and nonflavonoid phenolic intakes and compliance to fruit and vegetable intervention.

Synthesis and biological analysis of novel glycoside derivatives of L-AEP, as targeted antibacterial agents

To develop targeted methods for treating bacterial infections, the feasibility of using glycoside derivatives of the antibacterial compound L-R-aminoethylphosphonic acid (L-AEP) has been investigated. These derivatives are hypothesized to be taken up by bacterial cells via carbohydrate uptake mechanisms, and then hydrolysed in situ by bacterial borne glycosidase enzymes, to selectively afford L-AEP. Therefore the synthesis and analysis of ten glycoside derivatives of L-AEP, for selective targeting of specific bacteria, is reported. The ability of these derivatives to inhibit the growth of a panel of Gram-negative bacteria in two different media is discussed. β-Glycosides (12a) and (12b) that contained L-AEP linked to glucose or galactose via a carbamate linkage inhibited growth of a range of organisms with the best MICs being <0.75 mg/ml; for most species the inhibition was closely related to the hydrolysis of the equivalent chromogenic glycosides. This suggests that for (12a) and (12b), release of L-AEP was indeed dependent upon the presence of the respective glycosidase enzyme.

A combined X-ray and theoretical study of flavonoid compounds with anti-inflammatory activity

The structure of 7,4`-dimethoxy-3`-acetylflavone (tithonin-Ac) has been determined by X-ray diffraction and its geometry is compared with optimized geometrical parameters obtained by means of density functional theory at the B3LYP/6-311++G(d,p) level of calculation. in addition, vertical ionization potential (IPv) and acidity for tithonin-Ac and two derivatives have been also calculated. Calculations of spin densities were also performed for the radical formed by the electron abstraction of other flavones. The unpaired electron is located on C3 carbon atom (21-25%). (C) 2008 Elsevier B.V. All rights reserved.

Mutagenicity of paepalantine dimer and glycoside derivatives from Paepalanthus bromelioides

The first isocoumarin isolated from the methylene chloride extract of Paepalanthus bromelioides, named paepalantine (isocoumarin 1), was found to have antimicrobial activity; but, it is mutagenic clastogenic and cytotoxic. Two other isocoumarins, paepalantine-9-O-beta-D-glucopyranoside (isocoumarin 2) and paepalantine-9-O-beta-D-allopyranosyl(1-->6) glucopyranoside (isocoumarin 3) were isolated from the ethanolic extract. A fourth new isocoumarin, also isolated from the methylene chloride extract of the capitula of P. bromelioides, was characterized as an 8-8' dimer of paepalantine and denominated isocoumarin 4. The abilities of isocoumarins 2, 3 and 4 to induce mutations in Salmonella typhimurium strains TA97a, TA98, TA100 and TA102 were investigated. Mutagenic activity was observed in strain TA97a treated with isocoumarin 2 in the presence of S9 mixture. The substitution of H at position 9 by glucose or glucose-allose caused reductions in the mutagenic activities of paepalantine, indicating this to be an important site for these properties. (C) 2003 Elsevier Ltd. All rights reserved.

Comparison of polyamine, phenol and flavonoid contents in plants grown under conventional and organic methods

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Investigation of cytotoxic, apoptosis-inducing, genotoxic and protective effects of the flavonoid rutin in HTC hepatic cells

Rutin is a flavonoid with antioxidant, vasodilatory, anti-inflammatory and immune-stimulating activities. To study the toxicity of rutin and its protective effect, this work investigated the cytotoxic, apoptosis-inducing, genotoxic and protective effects of rutin in HTC cells. In the MTT assay, the highest concentration tested (810 mu M) showed cytotoxicity after 72 h of treatment, where cell viability and cell proliferation was diminished. None of the concentrations of rutin tested induced apoptosis after 24 h treatment. The highest concentration of rutin after 24 h treatment induced DNA damage, shown in the comet assay, but did have a genotoxic effect in the micronucleus test. Rutin was tested against the pro-carcinogenic agent benzo(a)pyrene, at concentrations of 90, 270 and 810 mu M, and was found to reduce induced DNA damage significantly. This protective effect of rutin against a pro-carcinogen, suggests an important biological activity for this compound, which can contribute to human health through the diet. (C) 2010 Elsevier GmbH. All rights reserved.

Functional characterization and target discovery of glycoside hydrolases from the digestome of the lower termite Coptotermes gestroi

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Structural basis for branching-enzyme activity of glycoside hydrolase family 57: Structure and stability studies of a novel branching enzyme from the hyperthermophilic archaeon Thermococcus Kodakaraensis KOD1

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antioxidant flavonol glycosides from Nectandra grandiflora (Lauraceae)

O fracionamento cromatográfico do extrato etanólico das folhas de Nectandra grandiflora resultou no isolamento de dois flavonóides glicosilados que apresentaram atividade antioxidante inibindo a oxidação do beta -caroteno em CCDC. As substâncias isoladas tiveram suas estruturas elucidadas através de técnicas espectrométricas de RMN uni- e bidimensional e foram identificadas como 3-O-beta -ramnosy kaempferol and 3-O-beta -ramnosylquercetina.

Characterization of flavonoid and naphthopyranone derivatives from Eriocaulon ligulatum using liquid chromatography tandem mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

PHYLOGENETIC STUDIES OF SOME SPECIES OF THE GENUS COFFEA .1. NUMERICAL-ANALYSIS OF FLAVONOID COMPOUNDS

Flavonoid compounds were analyzed in ripe fruit pulp of ten species of Coffea, including two cultivars of C. arabica and two of C. canephora. Three coefficients of similarity: Simple-Matching, Jaccard and Ochiai and three different clustering methods, Single Linkage, Complete Linkage and Unweighted Pair Group, Using Arithmetic Averages (UPGMA), were used to analyze the data.Jaccard and Ochiai's coefficients of association showed a more coherent result, when compared with taxonomic and hybridization studies. Inclusion of Psilanthopsis kapakata in the genus Coffea, as C. kapakata, is justified by the similarity of this species with other studied species, and clusters clearly approximate the species C. arabica and C. eugenioides. The latter is one of the possible parents of the allotetraploid species C. arabica, C. congensis is the only species whose position remains ambiguous, probably due to the fact that the plants of this species that were introduced into the Campinas collections, were hybrids and not typical of C. congensis.

Isolation and HPLC quantitative analysis of flavonoid glycosides from Brazilian beverages (Maytenus ilicifolia and M-aquifolium)

Aqueous infusions of Brazilian Maytenus leaves are used as beverages, foodstuffs, and phytomedicines. Previously, we isolated two new flavonoid tetrasaccharides from the infusion of Maytenus aquifolium leaves that showed antiulcer activity. In this investigation a new flavonoid tetrasaccharide, kaempferol-3-O-alpha -L-rhamnopyranosyl (1-6)-O-[alpha -L-arabinopyranosyl (1 -->3)-O-alpha -L-rhamnopyranosyl (1-2)]-O-beta -D-galactopyranoside (3), was isolated, together with kaempferol tri- and disaccharides and quercetin trisaccharides from the aqueous infusion of Maytenus ilicifolia leaves. All structures were elucidated by ES-MS and NMR spectroscopic methods. The quantitative analysis of the flavonoid glycosides from Maytenus ilicifolia and M. aquifolium has been performed by HPLC.

The use of classification methods for modeling the antioxidant activity of flavonoid compounds

A study using two classification methods (SDA and SIMCA) was carried out in this work with the aim of investigating the relationship between the structure of flavonoid compounds and their free-radical-scavenging ability. In this work, we report the use of chemometric methods (SDA and SIMCA) able to select the most relevant variables (steric, electronic, and topological) responsible for this ability. The results obtained with the SDA and SIMCA methods agree perfectly with our previous model, in which we used other chemometric methods (PCA, HCA and KNN) and are also corroborated with experimental results from the literature. This is a strong indication of how reliable the selection of variables is.

Antioxidant effect of saponin: potential action of a soybean flavonoid on glucose tolerance and risk factors for atherosclerosis

At the present time, much attention is being paid to antioxidant substances because many pathological conditions are associated with oxidative stress. The purpose of the present study was to discover the potency of saponin (2-phenyl-benzopyrane), a soybean flavonoid, with respect to its hypoglycaemic and hypolipidaemic action, and the association of these effects with oxidative stress. Male Wistar rats were divided into two groups (n = 6): control group and saponin-treated group (60 mg/kg) during 30 days. Saponin had no effects on glucose tolerance. Although no changes had been observed in low-density lipoprotein-cholesterol, saponin-treated animals had increased low-density lipoprotein-cholesterol/triacylglycerol ratio and decreased triacylglycerol, very low-density lipoprotein-cholesterol and total/high-density lipoprotein-cholesterol ratio than the control group. Saponin-treated rats showed lower lipid hydroperoxide than control rats, indicating decreased potential to atherosclerosis. No alterations were observed in antioxidant enzymes, superoxide dismutase and glutathione peroxidase, while lipid hydroperoxide were decreased in saponin-treated rats. In conclusion, the beneficial effects of saponin on serum lipids were related to a direct saponin antioxidant activity.