15 research outputs found
Urinary levels of trimethylsulfonium in the volunteers of the TMSe producers and TMSe non-producers group.
<p>Each bar shows the mean of trimethylsulfonium urinary concentration for 5 consecutive days and the standard error of the mean (SEM). The inset shows a zoomed-in portion of the graph for TMS levels in TMSe-nonproducers.</p
The Association between the Urinary Excretion of Trimethylselenonium and Trimethylsulfonium in Humans
<div><p>Hydrogen sulfide is a signaling molecule that plays important roles in several physiological processes, and its methylation product trimethylsulfonium (TMS) is a natural constituent of human urine that could serve as a biomarker for hydrogen sulfide. In vitro studies showed that the enzyme indole-ethylamine N-methyltransferase (INMT) is responsible for the production of trimethylsulfonium as well as its selenium analogue trimethylselenonium (TMSe). Marked inter-individual variability in TMSe production is associated with genetic polymorphisms in the <i>INMT</i> gene, but it remains unclear whether these polymorphisms affect substrate specificity or general enzymatic activity. Therefore, we explore the association between the TMS and TMSe production phenotypes. Caucasian volunteers were recruited and grouped according to their TMSe status into “TMSe producers” and “TMSe non-producers”, and morning urine samples were collected over 5 consecutive days from each volunteer. A total of 125 urine samples collected from 25 volunteers (13 TMSe producers and 12 TMSe non-producers) were analyzed for total selenium and total sulfur using inductively coupled plasma mass spectrometry (ICPMS), trimethylselenonium using HPLC/ICPMS, and trimethylsulfonium using HPLC/electrospray ionization—triple quadrupole—mass spectrometry (ESI-QQQ-MS). Although there was no correlation between TMS and TMSe urinary levels within the “TMSe producers” group, the “TMSe producers” had urinary levels of TMS 10-fold higher than those of the “TMSe non-producers” <i>(P</i> < 0.001). This result indicates that stratification according to TMSe status or genotype is crucial for the correct interpretation of urinary TMS as a possible biomarker for hydrogen sulfide body pools.</p></div
Investigating the correlation between the urinary levels of TMS and TMSe in the TMSe producers group.
<p>The TMS levels were expressed as normalized concentrations (A) and fractions of total element excretion (B). Concentrations were normalized according to specific gravity.</p
Box and whiskers plot of the concentration of urinary trimethylsulfonium (A), the fraction of total urinary sulfur excreted as trimethylsulfonium (B), fraction of total urinary selenium excreted as trimethylselenonium by TMSe producers (C), and the urinary concentration of trimethylselenonium in TMSe producers (D).
<p>Volunteers 1–13 are the TMSe producers (shown in green bars). Volunteers 14–25 are the TMSe non-producers (shown in red bars). TMSe was detected in the TMSe non-producers (LOD = 0.8 nM) but always fell below the limit of quantification (LOQ = 2.6 nM). The graphs show the minimum, maximum, 25% percentile, 75% percentile, arithmetic mean (dot), and median (line) of five consecutive morning urine samples from each volunteer. Concentrations were normalized according to specific gravity.</p
Characteristics of the study groups.
<p>The values represent the mean ± SD, range.</p
Total selenium, total sulfur, trimethylselenonium (TMSe), and trimethylsulfonium (TMS) in the study groups.
<p>Total selenium, total sulfur, trimethylselenonium (TMSe), and trimethylsulfonium (TMS) in the study groups.</p
Simultaneous selenium and sulfur speciation analysis in cultivated Pleurotus pulmonarius mushroom
Selenium (Se) and sulfur (S) speciation analysis in edible and medicinal Se enriched P. pulmonarius extracts was performed. Mycelium, colonized substrate, and fruiting bodies at different harvesting times were analyzed using ion-pairing reversed-phase chromatography coupled to an ICPMS/MS detector. Extraction efficiencies in en-zymatically digested and aqueous extracts were between 45.3 and 109% for Se, depending on the sample type. Selenomethionine (Se-Met) was found to be the major Se-compound, together with a number of unknown Se-species. Cystine (Cys(2)), methionine (Met), and sulfate were also detected and quantified in all samples. Most of the Se-Met (84.0%) and met (75.8%) were found to be in free form in the fruiting body, in contrast with the mycelium where 53.4% of Se-Met and 80.5% of met is incorporated into proteins
Comparative investigation of selenium-enriched Pleurotus ostreatus and Ganoderma lucidum as natural sources of selenium supplementation
Selenium (Se) is an essential trace element for human health, but its nutritional supply is insufficient in large parts of the world. Mushrooms can be enriched in selenium and can serve as alternative and natural source of selenium supplementation. In the present study, two common mushroom species (Pleurotus ostreatus and Ganoderma lucidum), were enriched with two selenium compounds (selenite and selenate) to test their suitability as natural sources of selenium supplementation. Sharp differences in the the metabolic patterns of the fortified selenium were observed. Selenium was effectively metabolized in P. ostreatus but remained in inorganic form in G. lucidum. However, mushrooms extracts were effective in enhancing selenoprotein expression in cell lines. The present study highlights the importance of employing selenium speciation analysis with an element-selective technique to examine the metabolic products following mushroom fortification for nutritional purposes due to the different toxicological profile and bioavailability of different selenium biotransformation products