Metabolic studies with promagnon, methylclostebol and methasterone in the uPA+/+-SCID chimeric mice

Biotransformation of anabolic androgenic steroids in human skin cells

In comparison to well-known drug-metabolizing organs such as the liver, the metabolic capacity of human skin is still not well elucidated despite the widespread use of topical drug application. To gain a comprehensive insight into anabolic steroid metabolism in the skin, six structurally related anabolic androgenic steroids, testosterone, metandienone, methyltestosterone, clostebol, dehydrochloromethyltestosterone, and methylclostebol, were applied to human keratinocytes and fibroblasts derived from the juvenile foreskin. Phase I metabolites obtained from incubation media were analyzed by gas chromatography-mass spectrometry. The 5α-reductase activity was predominant in the metabolic pathways as supported by the detection of 5α-reduced metabolites after incubation of testosterone, methyltestosterone, clostebol, and methylclostebol. Additionally, the stereochemistry structures of fully reduced metabolites (4α,5α-isomers) of clostebol and methylclostebol were newly confirmed in this study by the help of inhouse synthesized reference materials. The results provide insights into the steroid metabolism in human skin cells with respect to the characteristics of the chemical structures.

Steroids Bearing Heteroatom as Potential Drugs for Medicine

Heteroatom steroids, a diverse class of organic compounds, have attracted significant attention in the field of medicinal chemistry and drug discovery. The biological profiles of heteroatom steroids are of considerable interest to chemists, biologists, pharmacologists, and the pharmaceutical industry. These compounds have shown promise as potential therapeutic agents in the treatment of various diseases, such as cancer, infectious diseases, cardiovascular disorders, and neurodegenerative conditions. Moreover, the incorporation of heteroatoms has led to the development of targeted drug delivery systems, prodrugs, and other innovative pharmaceutical approaches. Heteroatom steroids represent a fascinating area of research, bridging the fields of organic chemistry, medicinal chemistry, and pharmacology. The exploration of their chemical diversity and biological activities holds promise for the discovery of novel drug candidates and the development of more effective and targeted treatments.

Structural transformation of methasterone with Cunninghamella blakesleeana and Macrophomina phaseolina

An anabolic-androgenic synthetic steroidal drug, methasterone (1) was transformed by two fungi, Cunninghamella blakesleeana and Macrophimina phaseclina. A total of six transformed products, 6β,7β,17β-trihydroxy-2α,17α-dimethyl-5α-androstane-3-one (2), 6β,7α,17β-trihydroxy-2α,17α-dimethyl-5α-androstane-3-one (3), 6α,17β-dihydroxy-2α,17α-dimethyl-5α-androstane-3,7-dione (4), 3β,6β,17β-trihydroxy-2α,17α-dimethyl-5α-androstane-7-one (5), 7α,17β-dihydroxy-2α,17α-dimethyl-5α-androstane-3-one (6), and 6β,9α,17β-trihydroxy-2α,17α-dimethyl-5α-androstane-3-one (7) were synthesized. Among those, compounds 2-5, and 7 were identified as new transformed products. MS, NMR, and other spectroscopic techniques were performed for the characterization of all compounds. Substrate 1 (IC50 = 23.9 ± 0.2 μg mL-1) showed a remarkable anti-inflammatory activity against nitric oxide (NO) production, in comparison to standard LNMMA (IC50 = 24.2 ± 0.8 μg mL-1). Whereas, its metabolites 2, and 7 showed moderate inhibition with IC50 values of 38.1 ± 0.5 μg mL-1, and 40.2 ± 3.3 μg mL-1, respectively. Moreover, substrate 1 was found to be cytotoxic for the human normal cell line (BJ) with an IC50 of 8.01 ± 0.52 μg mL-1, while metabolites 2-7 were identified as non-cytotoxic. Compounds 1-7 showed no cytotoxicity against MCF-7 (breast cancer), NCI-H460 (lung cancer), and HeLa (cervical cancer) cell lines.

Recent advances in identifying and utilizing metabolites of selected doping agents in human sports drug testing

Probing for evidence of the administration of prohibited therapeutics, drugs and/or drug candidates as well as the use of methods of doping in doping control samples is a central assignment of anti-doping laboratories. In order to accomplish the desired analytical sensitivity, retrospectivity, and comprehensiveness, a considerable portion of anti-doping research has been invested into studying metabolic biotransformation and elimination profiles of doping agents. As these doping agents include lower molecular mass drugs such as e.g. stimulants and anabolic androgenic steroids, some of which further necessitate the differentiation of their natural/endogenous or xenobiotic origin, but also higher molecular mass substances such as e.g. insulins, growth hormone, or siRNA/anti-sense oligonucleotides, a variety of different strategies towards the identification of employable and informative metabolites have been developed. In this review, approaches supporting the identification, characterization, and implementation of metabolites exemplified by means of selected doping agents into routine doping controls are presented, and challenges as well as solutions reported and published between 2010 and 2020 are discussed.

P450-Humanized and Human Liver Chimeric Mouse Models for Studying Xenobiotic Metabolism and Toxicity

Preclinical evaluation of drug candidates in experimental animal models is an essential step in drug development. Humanized mouse models have emerged as a promising alternative to traditional animal models. The purpose of this mini-review is to provide a brief survey of currently available mouse models for studying human xenobiotic metabolism. Here, we describe both genetic humanization and human liver chimeric mouse models, focusing on the advantages and limitations while outlining their key features and applications. Although this field of biomedical science is relatively young, these humanized mouse models have the potential to transform preclinical drug testing and eventually lead to a more cost-effective and rapid development of new therapies.

Successful Engraftment of Human Hepatocytes in uPA-SCID and FRG® KO Mice

Mice with humanized chimeric liver are promising in vivo tools to evaluate the efficacy of novel compounds or vaccine induced antibodies directed against pathogens that infect the human liver. In addition they can be used to study the human-type metabolism of medicinal compounds and hepatotoxicity.

Biotransformation of anabolic compound methasterone with Macrophomina phaseolina, Cunninghamella blakesleeana, and Fusarium lini, and TNF-α inhibitory effect of transformed products

Microbial transformation of methasterone (1) was investigated with Macrophomina phaseolina, Cunninghamella blakesleeana, and Fusarium lini. Biotransformation of 1 with M. phaseolina yielded metabolite 2, while metabolites 3-7 were obtained from the incubation of 1 with C. blakesleeana. Metabolites 8-13 were obtained through biotransformation with F. lini. All metabolites, except 13, were found to be new. Methasterone (1) and its metabolites 2-6, 9, 10, and 13 were then evaluated for their immunomodulatory effects against TNF-α, NO, and ROS production. Among all tested compounds, metabolite 6 showed a potent inhibition of proinflammatory cytokine TNF-α (IC50=8.1±0.9μg/mL), as compared to pentoxifylline used as a standard (IC50=94.8±2.1μg/mL). All metabolites were also evaluated for the inhibition of NO production at concentration of 25μg/mL. Metabolites 6 (86.7±2.3%) and 13 (62.5±1.5%) were found to be the most potent inhibitors of NO as compared to the standard NG-monomethyl-l-arginine acetate (65.6±1.1%). All metabolites were found to be non-toxic against PC3, HeLa, and 3T3 cell lines. Observed inhibitory potential of metabolites 6 and 13 against pro-inflammatory cytokine TNF-α, as well as NO production makes them interesting leads for further studies.

Replacing PAPS: In vitro phase II sulfation of steroids with the liver S9 fraction employing ATP and sodium sulfate

In vitro technologies provide the capacity to study drug metabolism where in vivo studies are precluded due to ethical or financial constraints. The metabolites generated by in vitro studies can assist anti-doping laboratories to develop protocols for the detection of novel substances that would otherwise evade routine screening efforts. In addition, professional bodies such as the Association of Official Racing Chemists (AORC) currently permit the use of in-vitro-derived reference materials for confirmation purposes providing additional impetus for the development of cost effective in vitro metabolism platforms. In this work, alternative conditions for in vitro phase II sulfation using human, equine or canine liver S9 fraction were developed, with adenosine triphosphate (ATP) and sodium sulfate in place of the expensive and unstable co-factor 3'-phosphoadenosine-5'-phosphosulfate (PAPS), and employed for the generation of six representative steroidal sulfates. Using these conditions, the equine in vitro phase II metabolism of the synthetic or so-called designer steroid furazadrol ([1',2']isoxazolo[4',5':2,3]-5α-androstan-17β-ol) was investigated, with ATP and Na₂ SO₄ providing comparable metabolism to reactions using PAPS. The major in vitro metabolites of furazadrol matched those observed in a previously reported equine in vivo study. Finally, the equine in vitro phase II metabolism of the synthetic steroid superdrol (methasterone, 17β-hydroxy-2α,17α-dimethyl-5α-androstan-3-one) was performed as a prediction of the in vivo metabolic profile.

New Potential Biomarker for Methasterone Misuse in Human Urine by Liquid Chromatography Quadrupole Time of Flight Mass Spectrometry

In this study, methasterone urinary metabolic profiles were investigated by liquid chromatography quadrupole time of flight mass spectrometry (LC-QTOF-MS) in full scan and targeted MS/MS modes with accurate mass measurement. A healthy male volunteer was asked to take the drug and liquid-liquid extraction was employed to process urine samples. Chromatographic peaks for potential metabolites were hunted out with the theoretical [M - H](-) as a target ion in a full scan experiment and actual deprotonated ions were studied in targeted MS/MS experiment. Fifteen metabolites including two new sulfates (S1 and S2), three glucuronide conjugates (G2, G6 and G7), and three free metabolites (M2, M4 and M6) were detected for methasterone. Three metabolites involving G4, G5 and M5 were obtained for the first time in human urine samples. Owing to the absence of helpful fragments to elucidate the steroid ring structure of methasterone phase II metabolites, gas chromatography mass spectrometry (GC-MS) was employed to obtain structural information of the trimethylsilylated phase I metabolite released after enzymatic hydrolysis and the potential structure was inferred using a combined MS method. Metabolite detection times were also analyzed and G2 (18-nor-17β-hydroxymethyl-2α, 17α-dimethyl-androst-13-en-3α-ol-ξ-O-glucuronide) was thought to be new potential biomarker for methasterone misuse which can be detected up to 10 days.

Micronucleus as biomarkers of cancer risk in anabolic androgenic steroids users

The use of anabolic androgenic steroids (AAS) has grown among practitioners of recreational bodybuilding, with significant contributions of designer steroids, aiming muscle hypertrophy in healthy subjects. The abusive use of AAS in general is associated with adverse effects; one of the most worrisome is cancer development. The aim of this study was to evaluate the effectiveness of the cytokinesis block micronucleus (CBMN) test in human lymphocytes in identifying risk groups for cancer development in users of AAS. Blood was collected from 15 AAS users bodybuilders (G1), 20 non-users bodybuilders (G2) and 20 non-users sedentary (G3). MN analysis was performed on a minimum of 1000 binucleated lymphocytes. The occurrence of MN was significantly higher ( p < 0.05) in individuals of G1 compared to G2 and G3. The results indicate the sensitivity of CBMN in human lymphocytes in the identification of chromosomal damage in consequence of AAS.

Advances in the detection of designer steroids in anti-doping

The abuse of unknown designer androgenic anabolic steroids (AAS) is considered to be an issue of significant importance, as AAS are the choice of doping preference according to World Anti-doping Agency statistics. In addition, unknown designer AAS are preferred since the World Anti-doping Agency mass spectrometric identification criteria cannot be applied to unknown molecules. Consequently, cheating athletes have a strong motive to use designer AAS in order to both achieve performance enhancement and to escape from testing positive in anti-doping tests. To face the problem, a synergy is required between the anti-doping analytical science and sports anti-doping regulations. This Review examines various aspects of the designer AAS. First, the structural modifications of the already known AAS to create new designer molecules are explained. A list of the designer synthetic and endogenous AAS is then presented. Second, we discuss progress in the detection of designer AAS using: mass spectrometry and bioassays; analytical data processing of the unknown designer AAS; metabolite synthesis; and, long-term storage of urine and blood samples. Finally, the introduction of regulations from sports authorities as preventive measures for long-term storage and reprocessing of samples, initially reported as negatives, is discussed.

Liquid chromatography-high resolution/ high accuracy (tandem) mass spectrometry-based identification of in vivo generated metabolites of the selective androgen receptor modulator ACP-105 for doping control purposes

Selective androgen receptor modulators (SARMs) represent an emerging class of therapeutics which have been prohibited in sport as anabolic agents according to the regulations of the World Anti-Doping Agency (WADA) since 2008. Within the past three years, numerous adverse analytical findings with SARMs in routine doping control samples have been reported despite missing clinical approval of these substances. Hence, preventive doping research concerning the metabolism and elimination of new therapeutic entities of the class of SARMs are vital for efficient and timely sports drug testing programs as banned compounds are most efficiently screened when viable targets (for example, characteristic metabolites) are identified. In the present study, the metabolism of ACP-105, a novel SARM drug candidate, was studied in vivo in rats. Following oral administration, urine samples were collected over a period of seven days and analyzed for metabolic products by Liquid chromatography-high resolution/high accuracy (tandem) mass spectrometry. Samples were subjected to enzymatic hydrolysis prior to liquid-liquid extraction and a total of seven major phase-I metabolites were detected, three of which were attributed to monohydroxylated and four to bishydroxylated ACP-105. The hydroxylation sites were assigned by means of diagnostic product ions and respective dissociation pathways of the analytes following positive or negative ionization and collisional activation as well as selective chemical derivatization. The identified metabolites were used as target compounds to investigate their traceability in a rat elimination urine samples study and monohydroxylated and bishydroxylated species were detectable for up to four and six days post-administration, respectively.

Current status of prediction of drug disposition and toxicity in humans using chimeric mice with humanized liver

1. Human-chimeric mice with humanized liver have been constructed by transplantation of human hepatocytes into several types of mice having genetic modifications that injure endogenous liver cells. Here, we focus on liver urokinase-type plasminogen activator-transgenic severe combined immunodeficiency (uPA/SCID) mice, which are the most widely used human-chimeric mice. Studies so far indicate that drug metabolism, drug transport, pharmacological effects and toxicological action in these mice are broadly similar to those in humans. 2. Expression of various drug-metabolizing enzymes is known to be different between humans and rodents. However, the expression pattern of cytochrome P450, aldehyde oxidase and phase II enzymes in the liver of human-chimeric mice resembles that in humans, not that in the host mice. 3. Metabolism of various drugs, including S-warfarin, zaleplon, ibuprofen, naproxen, coumarin, troglitazone and midazolam, in human-chimeric mice is mediated by human drug-metabolizing enzymes, not by host mouse enzymes, and thus resembles that in humans. 4. Pharmacological and toxicological effects of various drugs in human-chimeric mice are also similar to those in humans. 5. The current consensus is that chimeric mice with humanized liver are useful to predict drug metabolism catalyzed by cytochrome P450, aldehyde oxidase and phase II enzymes in humans in vivo and in vitro. Some remaining issues are discussed in this review.

Detection of designer steroid methylstenbolone in "nutritional supplement" using gas chromatography and tandem mass spectrometry: elucidation of its urinary metabolites

The use of "nutritional supplements" containing unapproved substances has become a regular practice in amateur and professional athletes. This represents a dangerous habit for their health once no data about toxicological or pharmacological effects of these supplements are available. Most of them are freely commercialized online and any person can buy them without medical surveillance. Usually, the steroids intentionally added to the "nutritional supplements" are testosterone analogues with some structural modifications. In this study, the analyzed product was bought online and a new anabolic steroid known as methylstenbolone (2,17α-dimethyl-17β-hydroxy-5α-androst-1-en-3-one) was detected, as described on label. Generally, anabolic steroids are extensively metabolized, thus in-depth knowledge of their metabolism is mandatory for doping control purposes. For this reason, a human excretion study was carried out with four volunteers after a single oral dose to determine the urinary metabolites of the steroid. Urine samples were submitted to enzymatic hydrolysis of glucuconjugated metabolites followed by liquid-liquid extraction and analysis of the trimethylsilyl derivatives by gas chromatography coupled to tandem mass spectrometry. Mass spectrometric data allowed the proposal of two plausible metabolites: 2,17α-dimethyl-16ξ,17β-dihydroxy-5α-androst-1-en-3-one (S1), 2,17α-dimethyl-3α,16ξ,17β-trihydroxy-5α-androst-1-ene (S2). Their electron impact mass spectra are compatible with 16-hydroxylated steroids O-TMS derivatives presenting diagnostic ions such as m/z 231 and m/z 218. These metabolites were detectable after one week post administration while unchanged methylstenbolone was only detectable in a brief period of 45 h.