Detection of doping peptides and basic drugs in equine urine using liquid chromatography-mass spectrometry

The abuse of prohibited agents including peptides and basic small-molecule drugs is an area of great concern in horseracing due to their high potential to act as doping agents. These compound classes include agents such as growth hormone-releasing peptides, peptide analgesics, beta-2-adrenergic receptor agonists, and quaternary ammonium drugs that can be challenging to detect and regulate because of their chemical properties and potential rapid elimination following administration. The use of highly sensitive and selective analytical techniques such as liquid chromatography-mass spectrometry (LC-MS) is necessary to provide coverage of these substances and their potential metabolites. This study describes the development and validation of methodology capable of the detection of over 50 different peptide-based doping agents, related secretagogues, quaternary ammonium drugs, and other challenging small molecules in equine urine following solid-phase extraction using a mixed mode weak cation exchange sorbent. Following sample extraction, the compounds were analyzed using LC-MS with chromatographic separation via a reverse phase gradient and detection via selective reaction monitoring following introduction to a triple-stage quadrupole mass spectrometer using positive mode electrospray ionization. Validation parameters including limits of detection and quantitation, accuracy, precision, linear range, recovery, stability, and matrix effects were determined. Briefly, the limits of detection for most compounds were in the sub-ng/mL ranges with adequate precision and accuracy sufficient for an initial testing procedure. Stability studies indicated that most compounds were sufficiently stable to allow for effective screening using conditions commonly utilized in drug testing laboratories.

Endogenous nature of estra-4,9-diene-3,17-dione in entire male horses

Estra-4,9-diene-3,17-dione (dienedione) is an anabolic androgenic steroid (AAS) sold as a bodybuilding supplement. It is prohibited in both human and equine sports. With no report of 4,9-diene configuration in endogenous steroids, dienedione has long been considered a synthetic AAS. Nevertheless, the reoccurring detection of dienedione in colt (entire male horse) urine samples lead to the investigation of its possible endogenous nature in horses. This paper describes (i) the detection of naturally occurring dienedione in colts, (ii) the conjugation study of dienedione and (iii) the population study of free and glucuronide-conjugated dienedione in colt urine. Qualitative and quantitative analyses of dienedione content in colt urine were performed, employing liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Qualitative analyses showed that dienedione was endogenous in colt urine and mainly in the form of glucuronide conjugates. Glucuronidation of dienedione was believed to happen at 3-enol leading to dienedione-3-glucuronide. Upon the population study of free and glucuronide-conjugated dienedione in colt urine samples (n = 175), the mean ± SD was determined to be 2.5 ± 3.5 ng/ml. The population data fitted a normal distribution after a fifth root transformation with the exclusion of one outlier by Grubb's test. A possible in-house threshold was proposed at 30 ng/ml of free and glucuronide-conjugated dienedione in colt urine associated with a risk factor of 1 in 14,269 (with a degree of freedom of 173). This is the first report of endogenous dienedione in entire male horses and the approach for controlling its potential misuse by using a threshold is also presented.

Construction of an individual identification panel for horses using insertion and deletion markers

Individual identification and paternity testing are important for avoiding inbreeding in the management of small populations of wild and domestic animals. In horse racing industries, they are extremely important for identifying and registering individuals and doping control to ensure fair competition. In this study, we constructed an individual identification panel for horses by using insertion and deletion (INDEL) markers. The panel included 39 INDEL markers selected from a whole-genome INDEL database. Genotyping of 89 Thoroughbreds showed polymorphisms with minor allele frequencies (MAFs) of 0.180-0.489 in all markers. The total probability of exclusion for paternity testing, power of discrimination, and probability of identity were 0.9994271269, >0.9999999999, and 0.9999999987, respectively. The panel was applied to 13 trios (sires, dams, and foals), and no contradictions were observed in genetic inheritance among the trios. When this panel was applied to the trios (52 trios) containing false fathers, an average of 7.3 markers excluded parentage relationships. In addition, genomic DNA extracted from the urine of six horses was partially genotyped for 39 markers, and 6-28 markers were successfully genotyped. The newly constructed panel has two advantages: a low marker mutation rate compared with short tandem repeats and a genotyping procedure that is as simple as short tandem repeat typing compared with single nucleotide variant typing. This panel can be applied for individual identification, paternity determination, and urine-sample identification in Thoroughbred horses.

Towards Non-Targeted Screening of Lipid Biomarkers for Improved Equine Anti-Doping

The current approach to equine anti-doping is focused on the targeted detection of prohibited substances. However, as new substances are rapidly being developed, the need for complimentary methods for monitoring is crucial to ensure the integrity of the racing industry is upheld. Lipidomics is a growing field involved in the characterisation of lipids, their function and metabolism in a biological system. Different lipids have various biological effects throughout the equine system including platelet aggregation and inflammation. A certain class of lipids that are being reviewed are the eicosanoids (inflammatory markers). The use of eicosanoids as a complementary method for monitoring has become increasingly popular with various studies completed to highlight their potential. Studies including various corticosteroids, non-steroidal anti-inflammatories and cannabidiol have been reviewed to highlight the progress lipidomics has had in contributing to the equine anti-doping industry. This review has explored the techniques used to prepare and analyse samples for lipidomic investigations in addition to the statistical analysis and potential for lipidomics to be used for a longitudinal assessment in the equine anti-doping industry.

Metabolomics in clinical and forensic toxicology, sports anti-doping and veterinary residues

Metabolomics is a multidisciplinary field providing workflows for complementary approaches to conventional analytical determinations. It allows for the study of metabolically related groups of compounds or even the study of novel pathways within the biological system. The procedural stages of metabolomics; experimental design, sample preparation, analytical determinations, data processing and statistical analysis, compound identification and validation strategies are explored in this review. The selected approach will depend on the type of study being conducted. Experimental design influences the whole metabolomics workflow and thus needs to be properly assessed to ensure sufficient sample size, minimal introduced and biological variation and appropriate statistical power. Sample preparation needs to be simple, yet potentially global in order to detect as many compounds as possible. Analytical determinations need to be optimised either for the list of targeted compounds or a universal approach. Data processing and statistical analysis approaches vary widely and need to be better harmonised for review and interpretation. This includes validation strategies that are currently deficient in many presented workflows. Common compound identification approaches have been explored in this review. Metabolomics applications are discussed for clinical and forensic toxicology, human and equine sports anti-doping and veterinary residues.

Measurements of Hydrocortisone and Cortisone for Longitudinal Profiling of Equine Plasma by LC-MS/MS

The conventional detection of exogenous drugs in equine doping samples has been used for confirmation and subsequent prosecution of participants responsible. In recent years, alternative methods using indirect detection have been investigated due to the expanding number of pharmaceutical agents available with the potential of misuse. The monitoring of endogenous biomarkers such as hydrocortisone (HC) has been studied in equine urine with an international threshold of 1 μg/ml established; however, there is no current threshold for equine plasma. The aim of this research was to investigate plasma concentrations of HC and cortisone (C) in race day samples compared to an administration of Triamcinolone Acetonide (TACA). The reference population (n = 1150) provided HC (6 to 145 ng/ml) and C (0.7 to 13 ng/ml) levels to derive the HC to C ratio (HC/C). Population reference limits (PRLs) were proposed for HC/C values at 0.2 (lower) and 61 (upper). Administration of TACA resulted in down‐regulation of HC/C values below the estimated PRLs for up to 96 h post‐administration. This indirect detection period was longer than the detection of TACA for 72 h. The use of individual reference limits (IRLs) for HC/C values was investigated to support the Equine Biological Passport (EBP), an intelligence model developed by Racing NSW for longitudinal monitoring of biomarkers.

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

In order to overcome the challenge associated with the screening of Anabolic-Androgenic Steroids (AAS) abuses in animal competitions, a non-targeted LC-HRMS based metabolomics approach was implemented on equine urine samples to highlight potential biomarkers associated with the administration of such compounds, using testosterone esters as model steroids. A statistical model relying on 4 potential biomarkers intensity could be defined to predict the status of the samples. With a routine application perspective, the monitoring of the highlighted potential biomarkers was first transferred into high-throughput LC-SRM. The model's performances and robustness of the approach were preserved and providing a first demonstration of metabolomics-based biomarkers integration within a targeted workflow using common benchtop MS instrumentation. In addition, with a view to the widespread implementation of such biomarker-based tools, we have transferred the method to a second laboratory with similar instrumentation. This proof of concept allows the development and application of biomarker-based strategies to meet current doping control needs.

Transcriptomic Markers of Recombinant Human Erythropoietin Micro-Dosing in Thoroughbred Horses

Recombinant human erythropoietin (rHuEPO) is a well-known performance enhancing drug in human athletes, and there is anecdotal evidence of it being used in horse racing for the same purpose. rHuEPO, like endogenous EPO, increases arterial oxygen content and thus aerobic power. Micro-doping, or injecting smaller doses over a longer period of time, has become an important concern in both human and equine athletics since it is more difficult to detect. Horses offer an additional challenge of a contractile spleen, thus large changes in the red blood cell mass occur naturally. To address the challenge of detecting rHuEPO doping in horse racing, we determined the transcriptomic effects of rHuEPO micro-dosing over seven weeks in exercised Thoroughbreds. RNA-sequencing of peripheral blood mononuclear cells isolated at several time points throughout the study identified three transcripts (C13H16orf54, PUM2 and CHTOP) that were significantly (PFDR < 0.05) different between the treatment groups across two or three time point comparisons. PUM2 and CHTOP play a role in erythropoiesis while not much is known about C13H16orf54, but it is primarily expressed in whole blood. However, gene expression differences were not large enough to detect via RT-qPCR, thereby precluding their utility as biomarkers of micro-doping.

Mass spectrometry based high-throughput bioanalysis of low molecular weight compounds: are we ready to support personalized medicine?

Liquid chromatography coupled to mass spectrometry (LC-MS) is the gold standard in bioanalysis for the development of quantitative assays to support drug development or therapeutic drug monitoring. High-throughput and low-cost gene sequencing have enabled a paradigm shift from one treatment fits all to personalized medicine (PM). However, gene monitoring provides only partial information about the health state. The full picture requires the combination of gene monitoring with the screening of exogenous compounds, metabolites, lipids, and proteins. This critical review discusses how mass spectrometry–based technologies and approaches including separation sciences, ambient ionization, and ion mobility are/could be used to support high-throughput bioanalysis of endogenous end exogenous low molecular weight compounds. It includes also various biological sample types (from blood to expired air), and various sample preparation techniques.

Detection and Confirmation of Zilpaterol in Equine Hair Using Liquid Chromatography - Mass Spectrometry

Zilpaterol is a β₂ -adrenergic agonist and a repartitioning agent that has a high potential for abuse in equine performance athletes. Analysis of zilpaterol in hair is an alternative sampling matrix that extends detection time periods beyond those found in urine or blood samples. Our laboratory has been screening for zilpaterol in hair for many years and recently detected and confirmed its presence in official samples. Accordingly, a liquid chromatography - mass spectrometry method was developed and validated to detect and confirm zilpaterol in equine hair. Briefly, equine hair was decontaminated, cut, and pulverized prior to disruption and liquid-liquid extraction in basic conditions. Following extraction, the sample was introduced to an Agilent 1260 HPLC and zilpaterol was separated using a reverse phase gradient with a total run time of 12.5 minutes. Following chromatographic separation, zilpaterol and its corresponding stable isotope labeled internal standard were introduced via positive mode electrospray ionization to a Thermo Q-Exactive Plus mass spectrometer and spectra collected using parallel reaction monitoring. The methodology was validated using in-house criteria including characterization of accuracy, precision, recovery, linear range, matrix effects, limit of detection and limit of quantitation and the method was found to be fit-for-purpose to confirm the presence of zilpaterol in equine hair. This methodology has been used to detect and confirm the presence of zilpaterol from out-of-competition hair samples submitted by regional racing authorities.

Establishment of a post-race biomarkers database and application of pathway analysis to identify potential biomarkers in post-race equine plasma

In the context of doping control, conventional direct chemical testing detects only a limited scope of target substances in equine biological samples. To expand the ability to detect doping agents and their detection windows, metabolomics has recently become a common approach for monitoring alteration of biomarkers caused by doping agents in relevant metabolic pathways. In horse racing, remarkable changes in metabolic profiles between the rest state and racing are likely to affect the identification of doping biomarkers. Previously, we reported a limited number of significantly upregulated metabolites after racing, based on a non-targeted metabolomics approach using out-of-competition and post-race equine plasma samples. In this study, we performed a more thorough analysis of the data set, using pathway analysis to establish a post-race biomarkers database (PBD) that includes upregulated and downregulated metabolites, their fold changes, and relevant pathways, with the main objective of improving our understanding of changes in physiological status related to horse racing. Statistical analysis of the PBD revealed that two peak combinations of pentadecanoyl carnitine/galactosylglycerol (P/G) and heptadecanoyl carnitine/galactosylglycerol (H/G) could be used as potential biomarkers for the discrimination of the rest and post-race groups. To demonstrate the applicability of the PBD, we validated the post-race biomarkers P/G and H/G (highly involved in lipid metabolism) by a single-blind test. This strategy, which combines establishment of a biomarker database with pathway analysis, represents a powerful tool for discovering potential doping biomarkers in the future.

Doping detection in animals: A review of analytical methodologies published from 1990 to 2019

Despite the impressive innate physical abilities of horses, camels, greyhounds, or pigeons, doping agents might be administered to these animals to improve their performance. To control these illegal practices, anti-doping analytical methodologies have been developed. This review compiles the analytical methods that have been published for the detection of prohibited substances administered to animals involved in sports over 30 years. Relevant papers meeting the search criteria that discussed analytical methods aiming to detect and/or quantify doping substances in animal biological matrices published from 1990 to 2019 were considered. A total of 317 studies were included, of which 298 were related to horses, demonstrating significant advances toward the development of doping detection methods for equine sports. However, analytical methods for the detection of doping agents in sports involving other species are lacking. Due to enhanced accuracy and specificity, chromatographic analysis coupled to mass spectrometry detection is preferred over immunoassays. Regarding biological matrices, blood and urine remain the first choice, although alternative biological matrices, such as hair and feces, have been considered. With the increasing number and type of drugs used as doping agents, the analytes addressed in the published papers are diverse. It is very important to continue to detect and quantify these drugs, recognizing those that are most frequently used, in order to punish the abusers, protect animals' health, and ensure a healthier and genuine competition.

External application of two unrestricted herbal medicines to treat costochondritis in a young collegiate athlete: A case report

Costochondritis (ChC), especially chronic ChC, typically manifests as spontaneous vague pain in anterior chest area and often occurs in adolescents for unknown reasons; it has prevented many collegiate athletes from participating in physical training and competitions. A 21-year-old female collegiate taekwondo athlete suffering from chronic chest pain was sent by her coaches for diagnosis and treatment. Seated motion palpation was used to identify spontaneous and motion-involved pain areas. Palpation in the supine position was used to initially rule out breast diseases. X-ray, electrocardiogram, and cardiac Doppler ultrasound were used in conjunction with myocardial enzyme testing to rule out lung and cardiovascular diseases. The patient was treated using herbal medicines applied via an external patch. The medicine was comprised of Rhizoma Corydalis and borneol, and the treatment lasted for seven weeks. For five weeks patches were applied at a frequency of two or three times per day, followed by a two-week period of once per day. The patient reported that the pain was relieved after two weeks of external herb use, and the autonomic chest pain had resolved. Re-examination after one month showed that her upper limb range of motion was close to normal, and her psychological burden had almost disappeared. It is possible to seek more active medicinal treatment and more practical external products for young athletes who is suffering chronic ChC that affects the sport training and competitive performances.

In slow pace towards the proteome of equine body fluids

Equine medicine represents a relevant field of veterinary science and the horse industry generates a significant economic impact. Horses can be involved in different sport disciplines, meat production, work and recreational purposes. Horses are also important for human health as they can be used as animal models for studying human diseases and in equine-assisted therapy. This review summarizes the data related to body fluids such as plasma/serum, urine, cerebrospinal fluid, synovial fluid, saliva, bronchoalveolar lavage fluid and peritoneal fluid obtained using proteomic analysis. Horse body fluid proteome analysis under various physiological and pathological conditions is a useful method for identifying new biomarkers for horse diseases which are still difficult to diagnose, but with serious consequences on equine health and welfare. The findings reported here reveal that further proteomic studies on equine body fluids collected from diseased animals are required. SIGNIFICANCE: Body fluids are sources of potential protein biomarkers for diagnosis and therapeutic target identification. Indeed, they contain proteins that play a crucial role in cell functions and whose presence or relative abundance are indicative of the health status of tissues/organs. The review reports the data on the equine body fluids obtained using proteomic analysis, including those which are commonly used to obtain a correct diagnosis and prognosis of horse diseases which still pose a significant challenge. For equine medicine, new biomarkers are needed to formulate early diagnosis and to distinguish among diseases with similar clinical signs.

Determination of bromhexine and its metabolites in equine serum samples by liquid chromatography - Tandem mass spectrometry: Applicability to the elimination study after single oral dose

Bromhexine (BH), expectorant used in the treatment of respiratory disorders associated with viscid or excessive mucus, is not permitted for use in the competing horse by many authorities in horseracing and Olympic disciplines. Metabolic studies are of the great importance in anti-doping field because they allow for updating the selection of the most appropriate markers for prohibited substances, such as metabolites present at higher concentration levels and/or lasted for a longer period of time in biological samples than a parent drug. This study describes LC-MS/MS-based method for simultaneous determination of BH and its metabolites, including 4-(2-amino-3,5-dibromobenzylamino)cyclohexanol (4-HDMB), 3-(2-amino-3,5-dibromobenzylamino)cyclohexanol (3-HDMB), in equine serum samples. The 2-(2-amino-3,5-dibromobenzylamino)cyclohexanol (2-HDMB) was monitored as well. The assay was validated in terms of linearity (R2 greater than 0.9951), intra- and inter-assay accuracy (91.6 - 109.1%) and precision (CV < 9.6%) as well as recovery (94.8 - 105.65%). The LODs were 0.0052, 0.0053, 0.0056 and 0.0043 ng/mL for BH, 2-HDMB, 3-HDMB and 4-HDMB, respectively. The developed method was applied to determine the time curses of BH and its metabolites concentrations in equine serum collected for 95.25 h following a single oral administration of BH to two healthy mares (in dose of 0.8 mg/kg). The parent drug was found at higher concentration levels than 3-HDMB (major metabolite) and 4-HDMB (minor metabolite), however, both BH metabolites lasted for a longer period of time in equine serum than the parent drug. Thus, both metabolites of BH can be considered as BH abuse markers.

Eternally Vulnerable: The Pathology of Abuse in Domestic Animals

Animals are amongst the most vulnerable of all sentient beings. Animal neglect and abuse may involve a single animal and one person, or hundreds of animals and many people. Animals and people are victims of the same types of fatal injury and severe neglect; however, the anatomy and physiology of different animal species and even breeds of animals are a unique challenge for veterinary pathologists. Identifying and describing external lesions of blunt force trauma and projectile wounds requires that the entire skin be reflected from the animal because fur and feathers partially or totally mask the injuries. Because quadrupeds or birds may react differently to the same traumatic force applied to bipedal humans, extrapolating from medical forensic pathology must be done with caution. Animal abuse, however, does not occur in a vacuum. An established link exists between animal abuse, interpersonal violence, and other serious crimes. Using examples, this paper describes specific injuries in abused and neglected animals in the context of domestic violence, interpersonal violence, mental illness, and drug addiction. Medical examiners should be aware that animal abuse affects not only the animal, but individuals, families, and society as a whole.