FROM A NON-TARGETED METABOLOMICS APPROACH TO A TARGETED BIOMARKERS STRATEGY TO HIGHLIGHT TESTOSTERONE ABUSE IN EQUINE. ILLUSTRATION OF A METHODOLOGICAL TRANSFER BETWEEN PLATFORMS AND LABORATORIES

Characterizing Lomerizine metabolites in camel urine: High-resolution mass spectrometry method development and validation for enhanced doping control

RATIONALE

Lomerizine (LMZ) is an antimigraine drug that works as a calcium channel blocker and has selective effects on the central nervous system. It is metabolized into trimetazidine (TMZ), which is a prohibited substance owing to its performance-enhancing effects in both human and animal sports. Effective doping control measures are imperative to distinguish the source of TMZ in samples to ensure integrity and fairness of the sport, therefore a comprehensive analysis of LMZ metabolites is essential to identify potential biomarkers in camel urine for effective doping control.

METHODS

Camel urine samples were collected from four healthy animals following a single oral administration of LMZ at a dosage of 1 mg/kg body weight. In vitro studies were conducted using homogenized camel liver samples. Lomerizine and its metabolites were extracted using solid-phase extraction and analyzed with a Thermo Fisher Orbitrap Exploris liquid chromatography mass spectrometry system. The acquired data was processed with the Compound Discoverer software.

RESULTS

The study conducted a comprehensive analysis of LMZ metabolites in camels and identified 10 phase I and one phase II metabolites. The primary pathway for the formation of phase I metabolites was de-alkylation, while phase II metabolite was formed through alkylation of the parent drug. The study provided valuable insights into the unique metabolic pathways of LMZ in camels under specific experimental conditions.

CONCLUSION

The developed method enables the detection and characterization of LMZ and its metabolites in camels. The identified metabolites has the potential to act as marker metabolites for the distinctive detection of LMZ in camel urine to ensure efficient analytical strategies for routine doping control applications.

Quantification of osilodrostat in horse urine using LC/ESI-HRMS to establish an elimination profile for doping control

Aim: The use of osilodrostat, developed as a medication for Cushing's disease but categorized as an anabolic agent, is banned in horses by both the International Federation of Horseracing Authorities and the Fédération Equestre Internationale. For doping control purposes, elimination profiles of hydrolyzed osilodrostat in horse urine were established and the detectability of free forms of osilodrostat and its major metabolite, mono-hydroxylated osilodrostat (M1c), was investigated.Materials & methods: Post-administration urine samples obtained from a gelding and three mares were analyzed to establish the elimination profiles of osilodrostat using a validated method involving efficient enzymatic hydrolysis followed by LC/ESI-HRMS analysis.Results: Applying the validated quantification method with an LLOQ of 0.05 ng/ml, hydrolyzed osilodrostat could be quantified in post-administration urine samples from 48 to 72 h post-administration; by contrast, both hydrolyzed osilodrostat and M1c were detected up to 2 weeks. In addition, confirmatory analysis identified the presence of hydrolyzed osilodrostat for up to 72 h post-administration.Conclusion: For doping control purposes, we recommend monitoring both hydrolyzed M1c and osilodrostat because of the greater detectability of M1c and the availability of a reference material of osilodrostat, which is essential for confirmatory analysis.

Presence and detection of endogenous steroids in the horse-A review

Detection of doping with steroids that are also endogenous in the horse can be challenging, and a variety of approaches to distinguish exogenous administration from their natural presence are employed. Knowledge of endogenous concentrations of various steroids in different genders of horses (intact male, castrated male and female) and factors that could naturally affect them is beneficial for establishing ways for detection of their use. The current internationally adopted approaches include concentration-based thresholds in urine and plasma, steroid ratios in urine and targeting the administered intact steroid esters in plasma and hair. However, these have their limitations, and therefore, other strategies, such as additional biomarkers and steroid profiling based on longitudinal testing and multivariate analysis, have been investigated and could potentially improve detection of the use of endogenous steroids in horses. This paper aims to provide a comprehensive overview of the steroids (androgens, oestrogens and progestogens) that have been reported to be endogenous to horses in literature, their concentration ranges in different genders and factors potentially affecting them as well as current and possible future approaches to detect their use.

Analytical advances in horseracing medication and doping control from 2018 to 2023

The analytical approaches taken by laboratories to implement robust and efficient regulation of horseracing medication and doping control are complex and constantly evolving. Each laboratory's approach will be dictated by differences in regulatory, economic and scientific drivers specific to their local environment. However, in general, laboratories will all be undertaking developments and improvements to their screening strategies in order to meet new and emerging threats as well as provide improved service to their customers. In this paper, the published analytical advances in horseracing medication and doping control since the 22nd International Conference of Racing Analysts and Veterinarians will be reviewed. Due to the unprecedented impact of COVID-19 on the worldwide economy, the normal 2-year period of this review was extended to over 5 years. As such, there was considerable ground to cover, resulting in an increase in the number of relevant publications included from 107 to 307. Major trends in publications will be summarised and possible future directions highlighted. This will cover developments in the detection of 'small' and 'large' molecule drugs, sample preparation procedures and the use of alternative matrices, instrumental advances/applications, drug metabolism and pharmacokinetics, the detection and prevalence of 'endogenous' compounds and biomarker and OMICs approaches. Particular emphasis will be given to research into the potential threat of gene doping, which is a significant area of new and continued research for many laboratories. Furthermore, developments in analytical instrumentation relevant to equine medication and doping control will be discussed.

Sample Preparation Techniques for Growth-Promoting Agents in Various Mammalian Specimen Preceding MS-Analytics

The misuse of growth-promoting drugs such as beta-2 agonists and steroids is a known problem in farming and sports competitions. Prior to the analysis of biological samples via liquid chromatography (LC)-mass spectrometry (MS) or gas chromatography (GC)-MS, sufficient sample preparation is required to reliably identify or determine the residues of drugs. In practice, broad screening methods are often used to save time and analyze as many compounds as possible. This review was conceptualized to analyze the literature from 2018 until October 2023 for sample preparation procedures applied to animal specimens before LC- or GC-MS analysis. The animals were either used in farming or sports. In the present review, solid phase extraction (SPE) was observed as the dominant sample clean-up technique for beta-2 agonists and steroids, followed by protein precipitation. For the extraction of beta-2 agonists, mixed-mode cation exchanger-based SPE phases were preferably applied, while for the steroids, various types of SPE materials were reported. Furthermore, dispersive SPE-based QuEChERs were utilized. Combinatory use of SPE and liquid-liquid extraction (LLE) was observed to cover further drug classes in addition to beta-2 agonists in broader screening methods.

Comparison of muscle metabolomics between two Chinese horse breeds

With their enormous muscle mass and athletic ability, horses are well-positioned as model organisms for understanding muscle metabolism. There are two different types of horse breeds-Guanzhong (GZ) horses, an athletic breed with a larger body height (~148.7 cm), and the Ningqiang pony (NQ) horses, a lower height breed generally used for ornamental purposes-both inhabited in the same region of China with obvious differences in muscle content. The main objective of this study was to evaluate the breed-specific mechanisms controlling muscle metabolism. In this study, we observed muscle glycogen, enzyme activities, and LC-MS/MS untargeted metabolomics in the gluteus medius muscle of six, each of GZ and NQ horses, to explore differentiated metabolites that are related to the development of two muscles. As expected, the glycogen content, citrate synthase, and hexokinase activity of muscle were significantly higher in GZ horses. To alleviate the false positive rate, we used both MS1 and MS2 ions for metabolite classification and differential analysis. As a result, a total of 51,535 MS1 and 541 MS2 metabolites were identified, and these metabolites can separate these two groups from each other. Notably, 40% of these metabolites were clustered into lipids and lipid-like molecules. Furthermore, 13 significant metabolites were differentially detected between GZ and NQ horses (fold change [FC] value ≥ 2, variable important in projection value ≥1, and Q value ≤ 0.05). They are primarily clustered into glutathione metabolism (GSH, p = 0.01), taurine, and hypotaurine metabolism (p < 0.05) pathways. Seven of the 13 metabolites were also found in thoroughbred racing horses, suggesting that metabolites related to antioxidants, amino acids, and lipids played a key role in the development of skeleton muscle in horses. Those metabolites related to muscle development shed a light on racing horses' routine maintenance and improvement of athletic performance.

Performance assessment of an equine metabolomics model for screening a range of anabolic agents

INTRODUCTION

Despite their ban, Anabolic Androgenic Steroids (AAS) are considered as the most important threat for equine doping purposes. In the context of controlling such practices in horse racing, metabolomics has emerged as a promising alternative strategy to study the effect of a substance on metabolism and to discover new relevant biomarkers of effect. Based on the monitoring of 4 metabolomics derived candidate biomarkers in urine, a prediction model to screen for testosterone esters abuse was previously developed. The present work focuses on assessing the robustness of the associated method and define its scope of application.

MATERIALS AND METHODS

Several hundred urine samples were selected from 14 different horses of ethically approved administration studies involving various doping agents' (AAS, SARMS, β-agonists, SAID, NSAID) (328 urine samples). In addition, 553 urine samples from untreated horses of doping control population were included in the study. Samples were characterized with the previously described LC-HRMS/MS method, with the objective of assessing both its biological and analytical robustness.

RESULTS

The study concluded that the measurement of the 4 biomarkers involved in the model was fit for purpose. Further, the classification model confirmed its effectiveness in screening for testosterone esters use; and it demonstrated its ability to screen for the misuse of other anabolic agents, allowing the development of a global screening tool dedicated to this class of substances. Finally, the results were compared to a direct screening method targeting anabolic agents demonstrating complementary performances of traditional and omics approaches in the screening of anabolic agents in horses.

Dapagliflozin Presented Nonalcoholic Fatty Liver Through Metabolite Extraction and AMPK/NLRP3 Signaling Pathway

In recent years, the incidence rate of nonalcoholic fatty liver disease (NAFLD) has been increasing year by year. The experiments conducted on rat elucidated the effect and underlying mechanism of dapagliflozin in NAFLD. Sprague Dawley rats were fed with HFD (Fat accounts for 52%, carbohydrate 34% and protein 14%) for 12 weeks as NAFLD model. Dapagliflozin presented NAFLD in rat model. Dapagliflozin reduced oxidative stress and inflammation in rat model of NAFLD. Dapagliflozin reduced oxidative stress and inflammation in vitro model of NAFLD. Dapagliflozin in a model of NAFLD metabolized into histamine H1 receptor, caffeine metabolism, mannose type O-glycan biosynthesis, choline metabolism in cancer, tryptophan metabolism, and glycerophospholipid metabolism. Dapagliflozin induced AMPK/NLRP3 signaling pathway. The regulation of AMPK/NLRP3 signaling pathway affected the effects of dapagliflozin on nonalcoholic fatty liver. In summary, dapagliflozin plays a preventative role in NAFLD through metabolite extraction, the inhibition of oxidative stress, and inflammation by AMPK/NLRP3 signaling pathway. Dapagliflozin may be a potential therapeutic agent for oxidative stress and inflammation in model of NAFLD.