Effects of dietary virgin olive oil polyphenols: hydroxytyrosyl acetate and 3, 4-dihydroxyphenylglycol on DSS-induced acute colitis in mice.

Hydroxytyrosol, a polyphenolic compound from extra virgin olive oil (EVOO) has exhibited an improvement in a model of DSS-induced colitis. However, other phenolic compounds present such as hydroxytyrosyl acetate (HTy-Ac) and 3,4-dihydroxyphenylglycol (DHPG) need to be explored to complete the understanding of the overall effects of EVOO on inflammatory colon mucosa. This study was designed to evaluate the effect of both HTy-Ac and DHPG dietary supplementation in the inflammatory response associated to colitis model. Six-week-old mice were randomized in four dietary groups: sham and control groups received standard diet, and other two groups were fed with HTy-Ac and DHPG, respectively, at 0.1%. After 30 days, all groups except sham received 3% DSS in drinking water for 5 days followed by a regime of 5 days of water. Acute inflammation was evaluated by Disease Activity Index (DAI), histology and myeloperoxidase (MPO) activity. Colonic expression of iNOS, COX-2, MAPKs, NF-kB and FOXP3 were determined by western blotting. Only HTy-Ac-supplemented group showed a significant DAI reduction as well as an improvement of histological damage and MPO. COX-2 and iNOS protein expression were also significantly reduced. In addition, this dietary group down-regulated JNK phosphorylation and prevented the DSS-induced nuclear translocation level of p65. However, no significant differences were observed in the FOXP3 expression. These results demonstrated, for the first time, that HTy-Ac exerts an antiinflammatory effect on acute ulcerative colitis. We concluded that HTy-Ac supplement might provide a basis for developing a new dietary strategy for the prevention of ulcerative colitis.

Dependence of palmar sweating response and central nervous system activity on the frequency of whole-body vibration.

OBJECTIVES: This study was carried out to determine the effects of the frequency of whole-body vibration on palmar sweating response and the activity of the central sympathetic nervous system. METHODS: Palmar sweating volume was measured on the right palm of six healthy men before and during 3 minutes of exposure to sinusoidal whole-body vibration at three different frequencies (16, 31.5, and 63 Hz). The whole-body vibration had a frequency-weighted, root mean square (rms) acceleration magnitude of 2.0 m/s2. As the index of the activated central sympathetic nervous system, saliva level of 3-methoxy-4-hydroxyphenylglycol (MHPG) was analyzed before and immediately after each vibration exposure. RESULTS: Each vibration frequency induced a palmar sweating response, that of 31.5 Hz being the largest. However, no significant difference was found between the three vibration conditions. Saliva MHPG increased in all the vibration exposures, and the largest change was observed at 31.5 Hz, the difference being significant. CONCLUSIONS: Acute exposure to whole-body vibration induced a palmar sweating response and activated the central sympathetic nervous system. The effects on the central nervous system were found to be dependent on the frequency of the vibration.

[A new solid-phase extraction method for human urinary 3-methoxy-4-hydroxyphenylethyleneglycol].

A new solid-phase extraction procedure for urinary 3-methoxy-4-hydroxy-phenylethyleneglycol (MHPG) was established. Sep-Pak Diol cartridge was used, because MHPG is a neutral and alcoholic compound. Aqueous samples were adsorbed to the cartridge, then MHPG was eluted by the addition of ethyl acetate. After the eluate was evaporated, the residuum was dissolved with HPLC mobile phase and injected into HPLC. The extraction procedure was highly specific to MHPG, and none of other acidic catecholamine metabolites, such as vanillylmandelic acid (VMA), homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC), was extracted. The recovery of MHPG using this method was over 90% and higher than those using previously described methods such as liquid-liquid extraction with ethyl acetate. Of the three vanillyl alcohol isomers, isovanillyl alcohol was the most suitable as an internal standard for the correction of column-to-column variation of the recovery. Human urinary unconjugated MHPG extracted by the new procedure could be measured by HPLC with a fluorescence detection. Further complicated derivatization and more sensitive detection systems, such as GC-MS and HPLC-electrochemical detector (ECD), were not needed due to high selectivity and high recovery of the extraction procedure. In addition, the urinary total (conjugated plus unconjugated) MHPG content could also be determined by the same procedure after an enzymatic hydrolysis of conjugated MHPG. The newly developed extraction procedure was simple, rapid and highly specific, and might be applicable to the analysis of MHPG in various body fluids.

Concurrent separation of catecholamines, dihydroxyphenylglycol, vasoactive intestinal peptide, and neuropeptide Y in superfusate and tissue extract.

A method is described for separation and quantification of 3,4-dihydroxyphenylglycol (DO-PEG), norepinephrine (NE), dopamine (DA), vasoactive intestinal peptide (VIP), and neuropeptide Y (NPY) from single samples of tissue homogenate and from superfusate from in vitro dog blood vessel preparations using cartridges containing 0.4 g of octadecylsilane (Sep-Pak C-18). Samples were passed through the cartridge at pH 7.4. A step-gradient system was used to first selectively desorb the catechols (DOPEG, NE, DA) with a moderately polar eluent; subsequently VIP and NPY were eluted with 2.5 ml of a mixture of 1% trifluoroacetic acid, 80% acetonitrile. Five Sep-Pak catechol eluents were tested. Catechols were quantified by HPLC with electrochemical detection and peptides by radioimmunoassay. An HPLC solvent system is described which is particularly useful for chromatography of the more hydrophilic catechols DOPEG, 3,4-dihydroxymandelic acid, and 3,4-dihydroxyphenylalanine concurrently with catecholamines. For superfusion studies, sample cleanup time was reduced to about 4 min per sample by attachment of the cartridges directly to the bottom of the superfusion chamber. Superfusate was subsequently pulled through the cartridges immediately after they were passed over the tissue. Batches of 12 high-speed tissue supernates were processed through the method in about 30 min. The method was used to analyze DOPEG, NE, DA, VIP, and NPY in various rat and dog tissues. The values obtained were similar to values obtained previously by other methods. Because the catechols and peptides are separated from a single sample, the method has several advantages over those described previously; e.g., it is rapid, simple, and more sensitive.

Urinary 3-methoxy-4-hydroxyphenylglycol determination using reversed-phase chromatography with amperometric detection.

A reversed-phase liquid chromatographic method with amperometric detection has been developed for the determination of urinary 3-methoxy-4-hydroxyphenylglycol. Before and after enzymatic deconjugation, it was purified by an extraction procedure and rapidly quantified under isocratic conditions. The 24-h excretion profile in normal human subjects (eight males and seven females) was determined; our results are consistent with those arrived at in a number of other studies. The present method is highly sensitive and selective; in addition, a good degree of precision is assured by use of 4-methoxy-3-hydroxyphenylglycol as internal standard.

Simultaneous determination of free 3-methoxy-4-hydroxymandelic acid and free 3-methoxy-4-hydroxyphenylethyleneglycol in plasma by liquid chromatography with electrochemical detection.

A new assay method is described for the simultaneous determination of free 3-methoxy-4-hydroxymandelic acid and 3-methoxy-4-hydroxyphenylethyleneglycol in plasma utilizing separation and purification by Bio-Gel P-10 followed by high-performance liquid chromatography with electrochemical detection. This technique is sensitive and reliable, and offers an inexpensive and practical alternative to gas chromatographic--mass fragmentographic methods for the monitoring of plasma levels of these catecholamine metabolites in the study of selective metabolic pathways of endogenous norepinephrine originating in the peripheral and the central nervous systems.

Gas chromatographic determination of urinary 3-methoxy-4-hydroxyphenylethyleneglycol sulphate after its ion-pair extraction.

In order to develop a gas chromatographic method with flame ionization detection for the analysis of urinary 3-methoxy-4-hydroxyphenylethyleneglycol sulphate, a new procedure for its isolation has been introduced. The conjugated metabolite has been extracted by an ion-pair technique using tetrabutyl ammonium as counter ion and dichloromethane as organic solvent. Hydrolysis and derivatization of 3-methoxy-4-hydroxyphenylethyleneglycol sulphate have been finally performed by treatment with heptafluorobutyric anhydride. Each step of the procedure, applied to the analysis of urine samples both from normal subjects and from patients with neuroblastoma, has been discussed.

Thin-layer chromatographic separation of the 3-O-methylated metabolites of noradrenaline.

The use of sodium borate impregnated thin-layer silica gel plates for the separation of noradrenaline and its 3-O-methylated metabolites is described. Its application to studies of the metabolism of tritiated I-noradrenaline by isolated tissues is illustrated for the rabbit uterus.