High levels of the health-relevant antioxidant selenoneine identified in the edible mushroom Boletus edulis.

Background: Selenoneine, the selenium analogue of the sulfur antioxidant ergothioneine, has been ascribed a multitude of beneficial health effects. Natural nutritional sources for this selenium species are, hence, of high interest. So far marine fish is the only significant selenoneine source consumed by larger parts of the population worldwide.

Selenoneine ameliorates peroxide-induced oxidative stress in C. elegans.

Scope: Selenoneine (2-selenyl-N, N, N-trimethyl-L-histidine), the selenium (Se) analogue of the ubiquitous thiol compound and putative antioxidant ergothioneine, is the major organic selenium species in several marine fish species. Although its antioxidant efficacy has been proposed, selenoneine has been poorly characterized, preventing conclusions on its possible beneficial health effects.

Methods And Results: Treatment of Caenorhabditis elegans (C.

Establishment of a Molding Procedure to Facilitate Formulation Development for Co-extrudates.

Co-extrusion offers a number of advantages over conventional manufacturing techniques. However, the setup of a co-extrusion line is cost- and time-intense and formulation development is challenging. This work introduces a novel procedure to test the applicability of a co-extruded reservoir-type system at an early product development stage.

Tracing cytotoxic effects of small organic Se species in human liver cells back to total cellular Se and Se metabolites.

Small selenium (Se) species play a major role in the metabolism, excretion and dietary supply of the essential trace element selenium. Human cells provide a valuable tool for investigating currently unresolved issues on the cellular mechanisms of Se toxicity and metabolism. In this study, we developed two isotope dilution inductively coupled plasma tandem-mass spectrometry based methods and applied them to human hepatoma cells (HepG2) in order to quantitatively elucidate total cellular Se concentrations and cellular Se species transformations in relation to the cytotoxic effects of four small organic Se species.

Human excretory products of selenium are natural constituents of marine fish muscle.

A selenosugar (selenosugar 1, methyl-2-acetamido-2-deoxy-1-seleno-β-D-galactopyranoside) was identified in aqueous extracts of muscle tissue of three marine fish species, mackerel (Scomber scombrus), sardine (Sardina pilchardus), and tuna (Thunnus albacares), by high-performance liquid chromatography coupled to elemental and high-resolution molecular mass spectrometry. Selenoneine (2-selenyl-Nα, Nα, Nα-trimethyl-L-histidine), a known selenium compound in fish, was the major form of selenium in the aqueous extracts, and the methylated derivative of selenoneine, namely Se-methylselenoneine, was also identified as a minor natural constituent in the fish. Selenosugar 1, a major urinary excretion product of selenium often found in organs and body fluids related to selenium excretion, has so far not been reported in muscle tissue.

Thio-dimethylarsinate is a common metabolite in urine samples from arsenic-exposed women in Bangladesh.

Over the last 6 years, much work on arsenic species in urine samples has been directed toward the determination of the reduced dimethylated arsenic species, DMA(III), because of its high toxicity and perceived key role in the metabolism of inorganic arsenic. Recent work, however, has suggested that DMA(III) may at times have been misidentified because its chromatographic properties can be similar to those of thio-dimethylarsinate (thio-DMA). We analyzed by HPLC-ICPMS (inductively coupled plasma mass spectrometry) urine samples from 75 arsenic-exposed women from Bangladesh with total arsenic concentrations ranging from 8 to 1034 microg As/L and found that thio-DMA was present in 44% of the samples at concentrations ranging mostly from trace amounts to 24 microg As/L (one sample contained 123 microg As/L).