Chronic adenosine A2A receptor blockade induces locomotor sensitization and potentiates striatal LTD IN GPR37-deficient mice

Adenosine A_2A receptors (A_2A R) play a key role in modulating dopamine-dependent locomotor activity, as heralded by the sensitization of locomotor activity upon chronic A_2A R blockade, which is associated with elevated dopamine levels and altered corticostriatal synaptic plasticity. Since the orphan receptor GPR37 has been shown to modulate A_2A R function in vivo, we aimed to test whether the A_2A R-mediated sensitization of locomotor activity is GPR37-dependent and involves adaptations of synaptic plasticity. To this end, we administered a selective A_2A R antagonist, SCH58261 (1 mg/kg, i.p.), daily for 14 days, and the locomotor sensitization, striatum-dependent cued learning, and corticostriatal synaptic plasticity (i.e., long-term depression) were compared in wild-type and GPR37^-/- mice. Notably, GPR37 deletion promoted A_2A R-associated locomotor sensitization but not striatum-dependent cued learning revealed upon chronic SCH58261 treatment of mice. Furthermore, chronic A_2A R blockade potentiated striatal long-term depression in corticostriatal synapses of GPR37^-/- but not of wild-type mice, thus correlating well with neurochemical alterations of the adenosinergic system. Overall, these results revealed the importance of GPR37 regulating A_2A R-dependent locomotor sensitization and synaptic plasticity in the basal ganglia circuitry. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/. Open Science: This manuscript was awarded with the Open Materials Badge. For more information see: https://cos.io/our-services/open-science-badges/.

Anthocyanins in aged blueberry-fed rats are found centrally and may enhance memory

Research has shown that fruits and vegetables containing high levels of polyphenolics (flavonoids) display high total antioxidant activity. Our laboratory found that various fruit and vegetable extracts, particularly blueberry (BB), were effective in reversing age-related deficits in neuronal signaling and behavioral parameters following 8 weeks of feeding, possibly due to their polyphenolic content. However, it was unclear if these phytonutrients were able to directly access the brain from dietary BB supplementation (BBS). The present study examined whether different classes of polyphenols could be found in brain areas associated with cognitive performance following BBS. Thus, 19 month old F344 rats were fed a control or 2% BB diet for 8-10 weeks and tested in the Morris water maze (MWM), a measure of spatial learning and memory. LC-MS analyses of anthocyanins in the diet and subsequently in different brain regions of BBS and control rats were carried out. Several anthocyanins (cyanidin-3-O-beta-galactoside, cyanidin-3-O-beta-glucoside, cyanidin-3-O-beta-arabinose, malvidin-3-O-beta-galactoside, malvidin-3-O-beta-glucoside, malvidin-3-O-beta-arabinose, peonidin-3-O-beta-arabinose and delphinidin-3-O-beta-galactoside) were found in the cerebellum, cortex, hippocampus or striatum of the BBS rats, but not the controls. These findings are the first to suggest that polyphenolic compounds are able to cross the blood brain barrier and localize in various brain regions important for learning and memory. Correlational analyses revealed a relationship between MWM performance in BBS rats and the total number of anthocyanin compounds found in the cortex. These findings suggest that these compounds may deliver their antioxidant and signaling modifying capabilities centrally.

An LC-MS-based metabolomics approach for exploring urinary metabolome modifications after cocoa consumption

Cocoa-phytochemicals have been related to the health-benefits of cocoa consumption. Metabolomics has been proposed as a powerful tool to characterize both the intake and the effects on the metabolism of dietary components. Human urine metabolome modifications after single cocoa intake were explored in a randomized, crossed, and controlled trial. After overnight fasting, 10 subjects consumed randomly either a single dose of cocoa powder with milk or water, or milk without cocoa. Urine samples were collected before the ingestion and at 0-6, 6-12, and 12-24-h after test-meals consumption. Samples were analyzed by HPLC-q-ToF, followed by multivariate data analysis. Results revealed an important effect on urinary metabolome during the 24 h after cocoa powder intake. These changes were not influenced by matrix as no global differences were found between cocoa powder consumption with milk or with water. Overall, 27 metabolites related to cocoa-phytochemicals, including alkaloid derivatives, polyphenol metabolites (both host and microbial metabolites) and processing-derived products such as diketopiperazines, were identified as the main contributors to the urinary modifications after cocoa powder intake. These results confirm that metabolomics will contribute to better characterization of the urinary metabolome in order to further explore the metabolism of phytochemicals and its relation with human health.

Antioxidant activity and phenolic composition of Lavandin (Lavandula x intermedia Emeric ex Loiseleur) waste

The phenolic content of lavandin waste obtained after the distillation of essential oils for the perfume industry was investigated to find an alternative use for this material. The antioxidant activity of different fractions as well as their total phenolic content were evaluated by different methods. Twenty-three phenolic compounds were identified by liquid chromatography coupled to ionspray mass spectrometry (LC/MS/MS), including phenolic acids, hydroxycinnamoylquinic acid derivatives, glucosides of hydroxycinnamic acids, and flavonoids, none of which have previously been reported in lavandin waste. Some structure-activity relationships were proposed by relating the type of scavenging activity of different fractions with the identified phenolic compounds. Contents of representative phenolic acids of Lamiaceae (chlorogenic and rosmarinic) were evaluated by high performance liquid chromatography-diode array detection (HPLC-DAD) and compared with those of other plant species.

HPLC–Tandem Mass Spectrometric Method to Characterize Resveratrol Metabolism in Humans

Background: Nutritional biomarkers are alternatives to traditional dietary assessment tools. We sought to develop a method for nutritional analysis of resveratrol, a phenolic compound with purported health-promoting properties, and to determine all resveratrol metabolites.

Methods: We obtained LDL and urine samples from 11 healthy male volunteers who had consumed 250 mL of Merlot red wine. We measured resveratrol and its metabolites with 96-well solid-phase extraction plates coupled with HPLC-tandem mass spectrometry. Hexestrol was used as the internal standard. Gradient chromatography in multiple reaction monitoring mode was performed on a Luna C18 column, maintained at 40 °C; m/z transitions were as follows: resveratrol, 227/185; resveratrol glucosides, 389/227; resveratrol glucuronides, 403/227; resveratrol sulfates, 307/227; taxifolin, 303/285; and hexestrol, 269/134.

Results: Standard calibration curves were linear at 4.4–3289.5 nmol/L. Residual analyses were 100% (3.2) for trans-resveratrol and 100% (11.1) for trans-piceid. In both matrices, imprecision (CV) was <10.8% at all concentrations. Detection limits for resveratrol were 0.2 nmol/L (LDL), 0.3 nmol/L (synthetic urine), and 4.0 nmol/L (blank urine). Resveratrol and metabolites were checked for stability, and no degradation was observed.

Conclusions: The HPLC–tandem mass spectrometry method enabled us to identify resveratrol sulfates in human LDL and to characterize the complete profile of resveratrol metabolism in human LDL and urine. This method provides an accurate index of exposure to resveratrol and its metabolites, which can be used as nutritional biomarkers for evaluating the biological effects of moderate wine intake on human health.

Detection and quantification of unbound phytochelatin 2 in plant extracts of Brassica napus grown with different levels of mercury

The mercury (Hg) accumulation mechanism was studied in rape (Brassica napus) plants grown under a Hg concentration gradient (0 microm-1,000 microm). Hg mainly accumulated in roots. Therefore, the presence of phytochelatins (PCs) was studied in the roots of the plants. The high stability of the PC-Hg multicomplexes (mPC-nHg) seems to be the main reason for the lack of previous Hg-PC characterization studies. We propose a modification of the method to detect and quantify unbound PC of Hg in plant extracts via high-performance liquid chromatography coupled to electrospray tandem mass spectrometry and inductively coupled plasma mass spectrometry in parallel. We separated the PC from the Hg by adding the chelating agent sodium 2,3-dimercaptopropanesulfonate monohydrate. We only detected the presence of PC after the addition of the chelating agent. Some multicomplexes mPC-nHg could be formed but, due to their large sizes, could not be detected. In this study, only PC(2) was observed in plant samples. Hg accumulation was correlated with PC(2) concentration (r(2) = 0.98).

Rapid high-performance liquid chromatography–electrospray ionization tandem mass spectrometry method for qualitative and quantitative analysis of virgin olive oil phenolic metabolites in human low-density lipoproteins

A rapid method for detection and quantification of metabolites of specific olive oil phenolic compounds (hydroxytyrosol monoglucuronide, hydroxytyrosol monosulfate, tyrosol glucuronide, tyrosol sulfate and homovanillic acid sulfate) in low-density lipoprotein (LDL) fractions by solid-phase extraction (SPE) and high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS) is described. A 3 microm particle size fast C18 Luna column, 5 cm x 2.0 mm I.D., was used at a flow rate of 0.6 mL/min with a mobile phase consisting of 0.1% (v/v) formic acid (A) and acetonitrile (B). A linear gradient profile was used for separation at column temperature 40 degrees C. The proposed chromatographic procedure is rapid without loosing its separation efficiency and sensitivity. Validation proofs were carried out for the method described, showing a linear system (r>0.99) and a recovery of 81.9 and 101.3% for hydroxytyrosol and homovanillic acid, respectively. The results show that this method is effective and can be used in routine analysis.

Characterization and quantification of phenolic compounds in olive oils by solid-phase extraction, HPLC-DAD, and HPLC-MS/MS

A simple and reproducible method for qualitative and quantitative analysis of phenolic compounds in virgin olive oils by solid-phase extraction (SPE), high performance liquid chromatography with diode array detector (HPLC-DAD), and HPLC-mass spectrometry (MS) in tandem mode was developed. The polar fraction was obtained from samples of three different virgin olive oils. Detection and quantification were performed at 280, 240, and 320 nm. For identification purposes, HPLC-MS/MS was equipped with turbo ion spray source in the negative-ion mode. Twenty compounds of twenty-three detected and quantified were characterized. The method showed satisfactory linearity (r > 0.99), good recovery, satisfactory precision, and appropriate limits of detection (LOD) and quantification (LOQ).

Separation and characterization of phenolic compounds in fennel (Foeniculum vulgare) using liquid chromatography-negative electrospray ionization tandem mass spectrometry

Liquid chromatography (LC) diode array detection (DAD) coupled to negative electrospray ionization (ESI) tandem mass spectrometry (MS/MS) was used for the rapid and sensitive identification of water-soluble phenolic compounds in fennel waste. The plant material was first extracted and then chromatographed on Sephadex LH-20 to afford seven fractions, each of them being subjected to LC-MS analysis. Identification of the compounds was carried out by interpretation of UV, MS, and MS/MS spectra. Forty-two phenolic substances were identified, 27 of which had not previously been reported in fennel, including hydroxycinnamic acid derivatives, flavonoid glycosides, and flavonoid aglycons.

Triacylglycerol markers of mature human milk

OBJECTIVES

To determine which triacylglycerol (TAG) species in mature human milk are less affected by external factors and may thus be considered as TAG markers, as well as to determine which species are most influenced by these external conditions. Furthermore, we examine the correlation between the TAG markers and their fatty acids (FAs).

SETTING AND SUBJECTS

Six healthy women from Barcelona (Catalonia, Spain).

DESIGN AND INTERVENTIONS

In order to obtain the maximum variability of sampling conditions, 40 mature human milk samples were collected from different mothers, on different days, at different times of the day, and from different breasts during and after both the baby's and mother's meal. TAG and FA profiles were determined and correlated. The TAG composition was determined by high-performance liquid chromatography with an evaporative light-scattering detector, and also with atmospheric pressure chemical ionisation mass spectrometry. FAs compositions were determined by gas chromatography.

RESULTS

The results were analysed using the SPSS statistical package and proved to be more variable than might have been found in a more restrictive sample design. Nevertheless, despite these conditions, some TAG species were found in relatively constant levels in mature human milk, and could thus be considered as markers of the mature milk TAG profile. TAG species that we can classify in this group were: LaMO, CaPO, LaCaO, LaPCa, LaOL, MPLn, LLO, LaOO, MPL, and MOL. The names do not indicate the location of fatty acids in the glycerol molecule. On the other hand, concentrations of other TAG species vary considerably between samples and consequently these may be understood to be especially affected by the external factors. TAGs like PaLS, MPO, PaOO, PPP, MPS, SPP, LOO, PPO, MOS, SSP, POL, and SOS are in this second group. Correlation between the TAG markers and their FAs was examined by Pearson's test and a significant correlation was found for some FAs.

CONCLUSIONS

The TAG species present in mature human milk are affected in different ways by external factors such as dietary intake, nutritional status, length of lactation, time of the day, etc. Some TAGs may be considered as markers of mature human milk as they are relatively constant under a wide range of sampling conditions and do not depend on the factors mentioned.

SPONSORSHIP

This study was supported by the Fundació Mestres Jané.

Physicochemical characterization and antimicrobial properties of rhamnolipids produced by Pseudomonas aeruginosa 47T2 NCBIM 40044

Pseudomonas aeruginosa 47T2, grown in submerged culture with waste frying oil as a carbon source, produced a mixture of rhamnolipids with surface activity. Up to 11 rhamnolipid homologs (Rha-Rha-C(8)-C(10); Rha-C(10)-C(8)/Rha-C(8)-C(10);Rha-Rha-C(8)-C(12:1); Rha-Rha-C(10)-C(10); Rha-Rha-C(10)-C(12:1); Rha-C(10)-C(10); Rha-Rha-C(10)-C(12)/Rha-Rha-C(12)-C(10); Rha-C(10)-C(12:1)/Rha-C(12:1)-C(10); Rha-Rha-C(12:1)-C(12); Rha-Rha-C(10)-C(14:1); Rha-C(10)-C(12)/Rha-C(12)-C(10)) were isolated from cultures of P. aeruginosa 47T2 from waste frying oil and identified by HPLC-MS analysis. This article deals with the production, isolation, and chemical characterization of the rhamnolipid mixture RL(47T2). The physicochemical and biological properties of RL(47T2) as a new product were also studied. Its surface tension decreased to 32.8 mN/m; and the interfacial tension against kerosene to 1 mN/m. The critical micellar concentration for RL(47T2) was 108.8 mg/mL. The product showed excellent antimicrobial properties. Antimicrobial activity was evaluated according to the minimum inhibitory concentration (MIC), the lowest concentration of an antimicrobial agent that inhibits development of visible microbial growth. Low MIC values were found for bacteria Serratia marcescens (4 microg/mL), Enterobacter aerogenes (8 microg/mL), Klebsiella pneumoniae (0.5 microg/mL), Staphylococcus aureus and Staphylococcus epidermidis (32 microg/mL), Bacillus subtilis (16 microg/mL), and phytopathogenic fungal species: Chaetonium globosum (64 microg/mL), Penicillium funiculosum (16 microg/mL), Gliocadium virens (32 microg/mL) and Fusarium solani (75 microg/mL).