Exposure of DNA to endo- and exogenous DNA binding chemicals can result in the formation of DNA adducts and is believed to be the first step in chemically induced carcinogenesis. DNA adductomics is a relatively new field of research which studies the formation of known and unknown DNA adducts in DNA due to exposure to genotoxic chemicals. In this study, a new UHPLC-HRMS(/MS)-based DNA adduct detection method was developed and validated. Four targeted DNA adducts, which all have been linked to dietary genotoxicity, were included in the described method; O(6)-methylguanine (O(6)-MeG), O(6)-carboxymethylguanine (O(6)-CMG), pyrimidopurinone (M1G) and methylhydroxypropanoguanine (CroG). As a supplementary tool for DNA adductomics, a DNA adduct database, which currently contains 123 different diet-related DNA adducts, was constructed. By means of the newly developed method and database, all 4 targeted DNA adducts and 32 untargeted DNA adducts could be detected in different DNA samples. The obtained results clearly demonstrate the merit of the described method for both targeted and untargeted DNA adduct detection in vitro and in vivo, whilst the diet-related DNA adduct database can distinctly facilitate data interpretation.

Doping control is a main priority for regulatory bodies of both the horse racing industry and the equestrian sports. Urine and blood samples are screened for the presence of hundreds of forbidden substances including anabolic-androgenic steroids (AASs). Based on the suspected endogenous origin of some AASs, with β-boldenone as the most illicit candidate, this study aimed to improve the knowledge of the naturally present AAS in horse urine. To this extent, a novel ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated according to the Association of Official Racing Chemists (AORC) and European Commission (EC) guidelines, proving the power of this new method. Low limits of detection (0.2 ng/mL), good reproducibility (percentage of standard deviation (%RSD) < 10%), high recovery (94.6 to 117.1%), selectivity and specificity, and a linear response (confirmed with R(2) > 0.99 and lack-of-fit analysis) were obtained for all included AASs. With this method, urine samples of 105 guaranteed untreated horses (47 geldings, 53 mares, and 5 stallions serving as a control) were screened for β-boldenone and five related natural steroids: androstadienedione (ADD), androstenedione (AED), alpha-testosterone (αT), beta-testosterone (βT), and progesterone (P). Progesterone, β-testosterone, and α-testosterone were detected in more than half of the horses at low concentrations (<2 ng/mL). Occasionally, not only testosterone and progesterone but also low concentrations of AED, ADD, and boldenone (Bol) were found (0.5-5 ng/mL). Graphical Abstract A sensitive, new and fully validated UHPLC-MS/MS method has been developed that is able to quantify low levels of anabolic-androgenic steroids naturally present in urine of untreated horses (mares and geldings).

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Abstract:To address the ever-growing group of health-conscious consumers, more and more nutritional and health claims are being used on food products. Nevertheless, only very few food constituents, including plant sterols, have been appointed an approved health claim (European Commission and Food and Drugs Administration). Plant sterols are part of those limited lists of approved compounds for their cholesterol-lowering properties but have been praised for their anti-inflammatory and anti-carcinogenic properties as well. Despite this indisputable reputation, direct quantitative data is still lacking for naturally present (conjugated) plant sterols in beverages. This study aimed to fill this gap by applying a validated extraction and UPLC-MS/MS detection method to a diverse range of everyday plant-based beverages. β-sitosterol-β-D-glucoside (BSSG) showed to be by far the most abundant sterol in all beverages studied, with concentrations up to 60-90 mg per 100 mL in plant-based milk alternatives and fresh fruit juices. Ergosterol (provitamin D 2 ) could be found in beers (0.8-6.1 µg per 100 mL, from the yeast) and occasionally in juices (17-29 µg per 100 mL). Overall, the results demonstrated that the concentrations of water-soluble sterol conjugates have been underestimated significantly and that specific plant-based beverages can be good, low-fat sources of these plant sterols.

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