The in vivo metabolism of Jungle Warfare in greyhounds.

Δ6-Methyltestosterone was reported as the main active ingredient of the purported "dietary supplement" Jungle Warfare. This compound is structurally similar to 17α-methyltestosterone, containing an additional Δ6 double bond, and is reported to possess notable androgenic activity, raising concerns over the potential for abuse of Jungle Warfare in sport. The in vivo metabolism of Δ6-methyltestosterone in greyhounds was investigated. Urinary phase I (unconjugated) and phase II (glucuronide) metabolites were detected following oral administration using liquid chromatography-mass spectrometry. No phase II sulfate metabolites were detected. The major phase I metabolite was confirmed as 16α,17ß-dihydroxy-17α-methylandrosta-4,6-dien-3-one by comparison with a synthetically-derived reference material. Minor amounts of the parent drug were also confirmed. Glucuronide conjugated metabolites were also observed, but were found to be resistant to hydrolysis using the Escherichia coli ß-glucuronidase enzyme. Qualitative excretion profiles, limits of detection, and extraction recoveries were determined for the parent drug and the major phase I metabolite. These results provide a method for the detection of Jungle Warfare abuse in greyhounds suitable for incorporation into routine screening methods conducted by anti-doping laboratories.

The in vivo metabolism of Furazadrol in greyhounds.

Samples of the 'dietary supplement' Furazadrol sourced through the internet have been reported to contain the designer anabolic androgenic steroids [1',2']isoxazolo[4',5':2,3]-5α-androstan-17ß-ol (furazadrol F) and [1',2']isoxazolo[4',3':2,3]-5α-androstan-17ß-ol (isofurazadrol IF). These steroids contain an isoxazole fused to the A-ring and were designed to offer anabolic activity while evading detection, raising concerns over the potential for abuse of this preparation in sports. The metabolism of Furazadrol (F:IF, 10:1) was studied by in vivo methods in greyhounds. Urinary phase II Furazadrol metabolites were detected as glucuronides after a controlled administration. These phase II metabolites were subjected to enzymatic hydrolysis by Escherichia coli ß-glucuronidase to afford the corresponding phase I metabolites. Using a library of synthetically derived reference materials, the identities of seven urinary Furazadrol metabolites were confirmed. Major confirmed metabolites were isofurazadrol IF, 4α-hydroxyfurazadrol 4α-HF and 16α-hydroxy oxidised furazadrol 16α-HOF, whereas the minor confirmed metabolites were furazadrol F, 4ß-hydroxyfurazadrol 4ß-HF, 16ß-hydroxyfurazadrol 16ß-HF and 16ß-hydroxy oxidised furazadrol 16ß-HOF. One major hydroxyfurazadrol and two dihydroxyfurazadrol metabolites remained unidentified. Qualitative excretion profiles, limits of detection and extraction recoveries were established for furazadrol F and major confirmed metabolites. These investigations identify the key urinary metabolites of Furazadrol following oral administration, which can be incorporated into routine screening by anti-doping laboratories to aid the regulation of greyhound racing.