**Background**
The androgen receptor (AR) is a nuclear receptor that plays a critical role in the development and maintenance of male sexual characteristics and muscle mass. Traditional androgen therapies often suffer from a lack of tissue selectivity, leading to undesirable side effects such as prostate enlargement or cardiovascular issues. Consequently, there is a significant research interest in developing selective androgen receptor modulators (SARMs) that can provide the benefits of androgenic activity in muscle and bone while minimizing effects on the prostate and other androgen-dependent organs. Such selectivity is particularly valuable in the development of hormonal male contraception. In this context, we will introduce a selective androgen receptor modulator – S-23.
**Definition**
S-23 is an orally active selective androgen receptor modulator (SARM) with a Ki value of 1.7 nM.
**In Vitro and In Vivo Studies**
According to the S-23 description, this compound is designed to induce AR-mediated transcriptional activation. In terms of S-23 in vitro activity, the compound induces AR-mediated transcriptional activation in CV-1 cells when administered at a concentration of 10 nM.
The S-23 biological activity has been further validated through animal studies. In S-23 In Vivo experiments using castrated male Sprague Dawley rats, the compound was administered subcutaneously (S.c.) daily for 14 days at dosages ranging from 0.01 to 3 mg. The results demonstrated that androgen-dependent organ weights increased in a dose-dependent manner. Specifically, the ED50 of S-23 in the prostate and levator ani muscle was found to be 0.43 and 0.079 mg/d, respectively. Notably, at a dose rate as low as 0.1 mg/d, S-23 was able to selectively maintain the weight of the levator ani muscle at the level of intact controls, while its effects on the prostate and seminal vesicles remained below 30% of those observed in intact controls. In conclusion, S-23 is a potent and selective androgen receptor modulator that demonstrates tissue-selective anabolic activity.
Keywords
S-23, 1010396-29-8, S23, S 23, Androgen Receptor, transcriptional, activation, CV-1, cells, castrated, prostate, seminal, vesicle, levator, ani, muscle, Inhibitor, inhibitor, inhibit
References
[1] Jones A, et al. Preclinical characterization of a (S)-N-(4-cyano-3-trifluoromethyl-phenyl)-3-(3-fluoro, 4-chlorophenoxy)-2-hydroxy-2-methyl-propanamide: a selective androgen receptor modulator for hormonal male contraception. Endocrinology. 2009;150(1):385-395.
[2] Thevis M, et al. Characterization of in vitro generated metabolites of the selective androgen receptor modulators S-22 and S-23 and in vivo comparison to post-administration canine urine specimens. Drug Test Anal. 2010;2(11-12):589-598.