Alterations in gut microbiota associated with a cafeteria diet and the physiological consequences in the host.

OBJECTIVE: Gut microbiota have been described as key factors in the pathophysiology of obesity and different components of metabolic syndrome (MetS). The cafeteria diet (CAF)-fed rat is a preclinical model that reproduces most of the alterations found in human MetS by simulating a palatable human unbalanced diet. Our objective was to assess the effects of CAF on gut microbiota and their associations with different components of MetS in Wistar rats. METHODS: Animals were fed a standard diet or CAF for 12 weeks. A partial least square-based methodology was used to reveal associations between gut microbiota, characterized by 16S ribosomal DNA gene sequencing, and biochemical, nutritional and physiological parameters. RESULTS: CAF feeding resulted in obesity, dyslipidemia, insulin resistance and hepatic steatosis. These changes were accompanied by a significant decrease in gut bacterial diversity, decreased Firmicutes and an increase in Actinobacteria and Proteobacteria abundances, which were concomitant with increased endotoxemia. Associations of different genera with the intake of lipids and carbohydrates were opposed from those associated with the intake of fiber. Changes in gut microbiota were also associated with the different physiological effects of CAF, mainly increased adiposity and altered levels of plasma leptin and glycerol, consistent with altered adipose tissue metabolism. Also hepatic lipid accretion was associated with changes in microbiota, highlighting the relevance of gut microbiota homeostasis in the adipose-liver axis. CONCLUSIONS: Overall, our results suggest that CAF feeding has a profound impact on the gut microbiome and, in turn, that these changes may be associated with important features of MetS.

Effects of Hesperidin Consumption on the Cardiovascular System in Pre- and Stage 1 Hypertensive Subjects: Targeted and Non-Targeted Metabolomic Approaches (CITRUS Study).

SCOPE: The aim of the present work is to determine new biomarkers of the biological effects of hesperidin in orange juice (OJ) applying a non-targeted metabolomics approach validated by targeted metabolomics analyses of compliance biomarkers. METHODS AND RESULTS: Plasma/serum and urine targeted (HPLC-MS/MS) and untargeted (1 H-NMR) metabolomics signatures are explored in a subsample with pre- and stage-1 hypertension subjects of the CITRUS study (N = 159). Volunteers received 500 mL day-1 of control drink, OJ, or hesperidin-enriched OJ (EOJ) for 12-weeks. A 6-h postprandrial study is performed at baseline. Targeted analyses reveals plasma and urine hesperetin 7-O-ß-d-glucuronide as the only metabolite differing between OJ and EOJ groups after 12-weeks consumption, and in urine is correlated with a decreased systolic blood pressure level. The non-targeted approach shows that after single dose and 12-weeks consumption of OJ and EOJ change several metabolites related with an anti-inflammatory and antioxidant actions, lower blood pressure levels and uremic toxins. CONCLUSIONS: Hesperetin 7-O-ß-d-glucuronide can be a candidate marker for distinguishing between the consumption of different hesperidin doses at 12-weeks consumption as well as a potential agent mediating blood pressure reduction. Moreover, changes in different endogenous metabolites can explain the mechanisms of action and the biological effects of hesperidin consumption.

Measurement of the interaction between mucin and oenological tannins by Surface Plasmon Resonance (SPR); relationship with astringency.

The interaction between stomach porcine mucin and 3 oenological tannins (extract of ellagitannins from oak, extract of gallotannins from gall nuts and extract of proanthocyanidins from grape seeds) was measured by Surface Plasmon Resonance (SPR). These tannins were analysed and their astringency was determined using the Astringency Index method and by tasting. The interaction constants were determined using a Biacore SPR device (1:1 Langmuir binding model). The results indicate that the ellagitannins are more astringent than gallotannins and those, in turn, are more astringent than seed proanthocyanidins if the richness of the commercial extracts is considered. The astringency index of these tannins had high correlation and regression coefficients with their kinetic and thermodynamic dissociation constants. This data support a hypothesis that astringency depends not only on the thermodynamic tendency to form the complex between tannins and salivary proteins but also probably on the time required to dissociate the complex.

Leishmanicidal activity of Maytenus illicifolia roots.

In vitro evaluation of leishmanicidal activity of aqueous and ethanolic extracts of Maytenus illicifolia against three species of Leishmania. The root extracts showed differential activity against parasites, whereas the aerial part of the extracts was inactive.

Differential release of cell-signaling metabolites by male and female bovine embryos cultured in vitro.

Male and female early bovine embryos show dimorphic transcription that impacts metabolism. Individual release of metabolites was examined in a 24h single culture medium from Day-6 male and female morulae that developed to Day-7 expanded blastocysts. Embryos were produced in vitro, fertilized with a single bull and cultured in SOFaaci+6  g/L BSA. The embryonic sex was identified (amelogenin gene amplification). Embryos (N = 10 males and N = 10 females) and N = 6 blank samples (i.e. SOFaaci+6  g/L BSA incubated with no embryos) were collected from 3 replicates. Metabolome was analyzed by UHPLC-TOF-MS in spent culture medium. After tentative identification, N = 13 metabolites significantly (P < 0.05; ANOVA) differed in their concentrations between male and female embryos, although N = 10 of these metabolites showed heterogeneity (Levene's test; P > 0.05). LysoPC(15:0) was the only metabolite found at higher concentration in females (fold change [FC] male to female = 0.766). FC of metabolites more abundant in male culture medium (N = 12) varied from 1.069 to 1.604. Chemical taxonomy grouped metabolites as amino-acids and related compounds (DL-2 aminooctanoic acid, arginine, 5-hydroxy-l-tryptophan, and palmitoylglycine); lipids (2-hexenoylcarnitine; Lauroyl diethanolamide; 5,6 dihydroxyprostaglandin F1a; LysoPC(15:0); DG(14:0/14:1(9Z)/0:0) and triterpenoid); endogenous amine ((S)-N-Methylsalsolinol/(R)-N-Methylsalsolinol); n-acyl-alpha-hexosamine (N-acetyl-alpha-d-galactosamine 1-phosphate); and dUMP, a product of pyrimidine metabolism. Among the compounds originally contained in CM, female embryos significantly depleted more arginine than males and blank controls (P < 0.001). Male and female embryos induce different concentrations of metabolites with potential signaling effects. The increased abundance of metabolites released from males is consistent with the higher metabolic activity attributed to such blastocysts.

In vitro cultured bovine endometrial cells recognize embryonic sex.

Endometrial cell co-culture (ECC) with single embryo may reflect endometrium responses in vivo. Bovine Day-6 in vitro-produced morulae were cultured until Day-8 in modified synthetic oviductal fluid (mSOF), or on the epithelial side of ECC. Expression of epithelial- and stromal-cell transcripts was analyzed by RT-PCR in ECC with one male (ME) or female embryo (FE). Concentrations of ARTEMIN (ARTN) and total protein were determined in epithelial cell-conditioned medium. ECCs yielded embryos with more cells in the inner cell mass than embryos cultured in mSOF. Embryos altered transcript expression only in epithelial cells, not in stromal ones. Thus, ME induced larger reductions than FE and controls (i.e., no embryos cultured) in hexose transporter solute carrier family 2 member 1 (SLC2A1) and member 5 (SLC2A5), connective tissue growth factor (CTGF), artemin (ARTN), and interferon alpha and beta receptors subunit IFNAR1 and IFNAR2. FE reduced SLC2A1 and SLC2A5, and increased ARTN expression with respect to controls. ME tended to reduce total protein concentration (P < 0.082) in ECC-conditioned medium, while ARTN protein and gene expressions strongly correlated (R > 0.90; P < 0.05) in the group of ME or FE, but not in controls (without embryo). Isolated male and female embryos may differentially release signaling factors that induce sexually dimorphic responses in endometrial cells.

Antibiotic phenol nor-triterpenes from Maytenus canariensis.

The new phenols 6-oxo-tingenol, 3-O-methyl-6-oxo-tingenol and 6-oxo-iguesterol were isolated from the root bark of Maytenus canariensis. Their structures were determined by 1H and 13C NMR spectroscopic studies, including HMQC, HMBC, DEPT and ROESY and chemical transformations. The synthesis of 6-oxo-tingenol was achieved from tingenone. These compounds exhibit antibiotic activity against Gram-positive bacteria.

Degradation of cyclin A is regulated by acetylation.

Cyclin A accumulates at the onset of S phase, remains high during G(2) and early mitosis and is degraded at prometaphase. Here, we report that the acetyltransferase P/CAF directly interacts with cyclin A that as a consequence becomes acetylated at lysines 54, 68, 95 and 112. Maximal acetylation occurs simultaneously to ubiquitylation at mitosis, indicating importance of acetylation on cyclin A stability. This was further confirmed by the observation that the pseudoacetylated cyclin A mutant can be ubiquitylated whereas the nonacetylatable mutant cannot. The nonacetylatable mutant is more stable than cyclin A WT (cycA WT) and arrests cell cycle at mitosis. Moreover, in cells treated with histone deacetylase inhibitors cyclin A acetylation increases and its stability decreases, thus supporting the function of acetylation on cyclin A degradation. Although the nonacetylatable mutant cannot be ubiquitylated, it interacts with the proteins needed for its degradation (cdks, Cks, Cdc20, Cdh1 and APC/C). In fact, its association with cdks is increased and its complexes with these kinases display higher activity than control cycA WT-cdk complexes. All these results indicate that cyclin A acetylation at specific lysines is crucial for cyclin A stability and also has a function in the regulation of cycA-cdk activity.

A new antibiotic nortriterpene quinone methide from Maytenus catingarum.

15alpha-Hydroxy-21-keto-pristimerine (1), a new nortriterpene quinone methide was isolated from the root bark of Maytenus catingarum along with other well-known related compounds, including pristimerine (2), tingenone, and 20alpha-hydroxy-tingenone. The structure of 1 was determined by means of 1H and 13C NMR spectroscopy, including homonuclear and heteronuclear correlations. Compound 1 showed antibiotic activity against Gram-positive bacteria.