Determination of stanozolol and 3'-hydroxystanozolol in rat hair, urine and serum using liquid chromatography tandem mass spectrometry

Liquid chromatographytandem mass spectrometry methods for determination of stanozolol and l6β-hydroxy-stanozolol in animal urine

Introduction

Because of the activities and effects they induce, hormones are prohibited for use for anabolic purposes in farm animals intended for slaughter, which is regulated in the European Union by relevant legal provisions. Therefore, there is an obligation to monitor residues of hormones in animals and food of animal origin to ensure consumer safety. A hormone banned but used formerly for fattening cattle, stanozolol, and its metabolite 16β-OH-stanozolol are synthetic compounds that belong to a large group of steroid hormones. This study investigates residues of these compounds in animal urine.

Material and Methods

From 2006-2022, 2,995 livestock urine samples were tested for stanozolol residues in Poland as part of the National Residue Monitoring Programme. A liquid chromatography-tandem mass spectrometry method to determine stanozolol and 16β-OH-stanozolol in animal urine was developed and validated according to the required criteria. Urine sample analysis was based on enzymatic hydrolysis of hormones potentially present in it to the free form, extraction of them from the sample with a mixture of n-hexane and butyl alcohol, purification of an extract on an NH2 amine column and finally, instrumental detection.

Results

The apparent recovery and precision parameters of the developed method were in line with the established criteria, while its decision limits CCα and detection capabilities CCβ were lower than the recommended concentration for analytical purposes set at 2 μg L-1 (valid until December 15, 2022; currently set as 0.5 μg L-1).

Conclusion

All examined samples were compliant with the evaluation criteria.

Determination of steroids in bovine hair: Validation of a microwave-assisted chemical derivatization method using liquid chromatography-tandem mass spectrometry and in vivo studies

Hair analysis has attracted great attention in the regulatory analysis of food-producing animals, particularly due to the wider detection window of veterinary drugs in this matrix and also the possibility of confirming parent drugs with minimum metabolization. This work involved the development and validation of a quantitative liquid chromatography-tandem mass spectrometry method to determine 25 steroids and steroid esters in bovine hair. Sensitivity was improved using a fast and effective microwave-assisted chemical derivatization with methoxyamine hydrochloride. The validation was conducted in accordance with the Decision 657/2002/EC guidelines. An animal experimentation procedure was performed on 12 bovine animals in which two commercial formulations containing boldenone undecylenate and testosterone propionate were administrated via intramuscular injections on the neck. The samples were collected for 78 days in which the detection of the administrated analytes was only observed near the application sites. For some of the monitored days, no analyte was detected on the neck area. Since the migration of the analytes was not observed in areas other than the application site, false-negative results should be carefully considered when monitoring animal hair samples.

Stanozolol administration combined with exercise leads to decreased telomerase activity possibly associated with liver aging

Anabolic agents are doping substances which are commonly used in sports. Stanozolol, a 17α‑alkylated derivative of testosterone, has a widespread use among athletes and bodybuilders. Several medical and behavioral adverse effects are associated with anabolic androgenic steroids (AAS) abuse, while the liver remains the most well recognized target organ. In the present study, the hepatic effects of stanozolol administration in rats at high doses resembling those used for doping purposes were investigated, in the presence or absence of exercise. Stanozolol and its metabolites, 16‑β‑hydroxystanozolol and 3'‑hydroxystanozolol, were detected in rat livers using liquid chromatography‑mass spectrometry (LC‑MS). Telomerase activity, which is involved in cellular aging and tumorigenesis, was detected by examining telomerase reverse transcriptase (TERT) and phosphatase and tensin homolog (PTEN) expression levels in the livers of stanozolol‑treated rats. Stanozolol induced telomerase activity at the molecular level in the liver tissue of rats and exercise reversed this induction, reflecting possible premature liver tissue aging. PTEN gene expression in the rat livers was practically unaffected either by exercise or by stanozolol administration.

An FT-Raman, FT-IR, and Quantum Chemical Investigation of Stanozolol and Oxandrolone

We have studied the Fourier Transform Infrared (FT-IR) and the Fourier transform Raman (FT-Raman) spectra of stanozolol and oxandrolone, and we have performed quantum chemical calculations based on the density functional theory (DFT) with a B3LYP/6-31G (d, p) level of theory. The FT-IR and FT-Raman spectra were collected in a solid phase. The consistency between the calculated and experimental FT-IR and FT-Raman data indicates that the B3LYP/6-31G (d, p) can generate reliable geometry and related properties of the title compounds. Selected experimental bands were assigned and characterized on the basis of the scaled theoretical wavenumbers by their total energy distribution. The good agreement between the experimental and theoretical spectra allowed positive assignment of the observed vibrational absorption bands. Finally, the calculation results were applied to simulate the Raman and IR spectra of the title compounds, which show agreement with the observed spectra.

Inhibitory Effects of Diclofenac on Steroid Glucuronidation In Vivo Do Not Affect Hair-Based Doping Tests for Stanozolol

In vitro studies show that diclofenac inhibits enzymatic steroid glucuronidation. This study was designed to investigate the influence of diclofenac on the excretion of stanozolol and 3′-hydroxystanozolol via analyses in hair, blood and urine in vivo in a rat study. Brown Norway rats were administered with stanozolol (weeks 1–3) and diclofenac (weeks 1–6). Weekly assessment of steroid levels in hair was complemented with spot urine and serum tests. Levels of both stanozolol and 3′-hydroxystanozolol steadily increased in hair during stanozolol treatment and decreased post-treatment, but remained readily detectable for 6 weeks. In contrast, compared to control rats, diclofenac significantly reduced urinary excretion of 3′-hydroxystanozolol which was undetectable in most samples. This is the first report of diclofenac altering steroid metabolism in vivo, detrimentally affecting detection in urine, but not in hair, which holds considerable advantages over urinalysis for anti-doping tests.

Determination of DNA damage and telomerase activity in stanozolol-treated rats

Anabolic androgenic steroids (AAS) are performance-enhancing drugs commonly abused by atheletes. Stanozolol is a synthetic testosterone-derived anabolic steroid. Although it is well known that AAS have several side-effects, there are only few toxicological studies available on the toxic effects and mechanisms of action of stanozolol. The aim of this study was to investigate the genotoxic effects of stanozolol and to determine its effects on telomerase activity in Sprague-Dawley male rats. For this purpose, 34 male rats were divided into 5 groups as follows: i) the control group (n=5); ii) the propylene glycol (PG)-treated group (n=5); iii) the stanozolol-treated group (n=8); iv) the PG-treated group subjected to exercise (n=8); and v) the stanozolol-treated group subjected to exercise (n=8). PG is used as a solvent control in our study. Stanozolol (5 mg/kg) and PG (1 ml/kg) were injected subcutaneously 5 days/week for 28 days. After 28 days, the animals were sacrificed, and DNA damage evaluation (comet assay) and telomerase activity assays were then performed using peripheral blood mononuclear cells (PBMCs). Telomerase activity was measured by using the TeloTAGGG Telomerase PCR ELISA PLUS kit. The results of this study revealed that stanozolol treatment induced DNA damage, while exercise exerted a protective effect. Stanozolol treatment without exercise stimulation was associated with a significant increase in telomerase activity in the PBMCs.

Simultaneous Determination of 11 Illicit Phenethylamines in Hair by LC-MS-MS: In Vivo Application

Existing phenethylamines are a class of synthetic compounds that differ from each other only in small changes to a largely conserved chemical structure. The recreational and illicit use of phenethylamines is a widespread problem. A simple procedure for the simultaneous quantitative determination in hair of 11 phenethylamines that are officially recognized as illicit by Italian legislation (p-methoxyamphetamine; p-methoxymethamphetamine; 3,4,5-trimethoxyamphetamine; 2,5-dimethoxyamphetamine; 2,5-dimethoxy-4-methylamphetamine; 2,5-dimethoxy-4-ethylamphetamine; 2,5-dimethoxy-4-bromoamphetamine; 2,5-dimethoxy-4-bromophenethylamine; 2,5-dimethoxy-4-iodophenethylamine; 2,5-dimethoxy-4-ethylthiophenethylamine and 2,5-dimethoxy-4-n-propylthiophenethylamine) has been developed and validated. Extraction from the matrix was performed after incubation in methanolic HCl and filtered reconstituted extracts were injected into a liquid chromatography/tandem mass spectrometry system (LC-MS-MS) without any further purification steps. This validated LC-MS-MS method has been used to determine the in vivo accumulation/retention of the above target analytes in hair after repeat oral administration to rats. This experiment further permitted investigation of the effect of pigmentation on the uptake of these phenethylamines by hair and the effect of hair pigmentation. The developed method could potentially be used for forensic and toxicological purposes, in the detection and quantitation of these illicit substances in human hair in workplace drug testing; drug-facilitated crime investigation; driver re-licensing; determining drug abuse history and postmortem toxicology.