Hydroxyflutamide

Hydroxyflutamide (HF, OHF) (developmental code name SCH-16423), or 2-hydroxyflutamide, is a nonsteroidal antiandrogen (NSAA) and the major active metabolite of flutamide, which is considered to be a prodrug of hydroxyflutamide as the active form.[1][2] It has been reported to possess an IC50 of 700 nM for the androgen receptor (AR), which is about 4-fold less than that of bicalutamide.[3]

Affinities of selected androgen receptor ligands

Compound AR RBA (%)
Metribolone 100
Dihydrotestosterone 85
Cyproterone acetate 7.8
Bicalutamide 1.4
Nilutamide 0.9
Hydroxyflutamide 0.57
Flutamide <0.0057
Notes: Human prostate tissue used for the assays. Sources: See template.

Relative affinities (%) of antiandrogens at steroid-hormone receptors

Antiandrogen AR PR ER GR MR
Cyproterone acetate 8–10 60 <0.1 5 1
Chlormadinone acetate 5 175 <0.1 38 1
Megestrol acetate 5 152 <0.1 50 3
Spironolactone 7 0.4a <0.1 2a 182
Trimethyltrienolone 3.6 <1 <1 <1 <1
Inocoterone 0.8 <0.1 <0.1 <0.1 <0.1
Inocoterone acetate <0.1 <0.1 <0.1 <0.1 <0.1
Flutamide <0.1 <0.1 <0.1 <0.1 <0.1
Hydroxyflutamide 0.5–0.8 <0.1 <0.1 <0.1 <0.1
Nilutamide 0.5–0.8 <0.1 <0.1 <0.1 <0.1
Bicalutamide 1.8 <0.1 <0.1 <0.1 <0.1
Notes: (1): Reference ligands (100%) were testosterone for the AR, progesterone for the PR, estradiol for the ER, dexamethasone for the GR, and aldosterone for the MR. (2): Tissues were rat prostate (AR), rabbit uterus (PR), mouse uterus (ER), rat thymus (GR), and rat kidney (MR). (3): Incubation times (0°C) were 24 hours (AR, a), 2 hours (PR, ER), 4 hours (GR), and 1 hour (MR). (4): Assay methods were different for bicalutamide for receptors besides the AR. Sources: See template.

Relative affinities of first-generation nonsteroidal antiandrogens for the androgen receptor

Species IC50 (nM) RBA (ratio)
Bicalutamide 2-Hydroxyflutamide Nilutamide Bica / 2-OH-flu Bica / nilu Ref
Rat 190 700 ND 4.0 ND [4]
Rat ~400 ~900 ~900 2.3 2.3 [5]
Rat ND ND ND 3.3 ND [6]
Rata 3595 4565 18620 1.3 5.2 [7]
Human ~300 ~700 ~500 2.5 1.6 [8]
Human ~100 ~300 ND ~3.0 ND [9]
Humana 2490 2345 5300 1.0 2.1 [7]
Footnotes: a = Controversial data. Sources: See template.

Relative potencies of selected antiandrogens

Antiandrogen Relative potency
Zanoterone 0.4
Cyproterone acetate 1.0
Flutamide 3.3
Hydroxyflutamide 3.5
Bicalutamide 4.3
Description: Relative potencies of orally administered antiandrogens in antagonizing 0.8 to 1.0 mg/kg s.c. testosterone propionate-induced ventral prostate weight increase in castrated immature male rats. Sources: See template.

References

  1. ^ Serra, C; Sandor, NL; Jang, H; Lee, D; Toraldo, G; Guarneri, T; Wong, S; Zhang, A; Guo, W; Jasuja, R; Bhasin, S (2013). "The effects of testosterone deprivation and supplementation on proteasomal and autophagy activity in the skeletal muscle of the male mouse: Differential effects on high-androgen responder and low-androgen responder muscle groups". Endocrinology. 154 (12): 4594–606. doi:10.1210/en.2013-1004. PMC 3836062. PMID 24105483.
  2. ^ Singh, Shankar; Gauthier, Sylvain; Labrie, Fernand (2000). "Androgen Receptor Antagonists (Antiandrogens) Structure-Activity Relationships". Current Medicinal Chemistry. 7 (2): 211–247. doi:10.2174/0929867003375371. ISSN 0929-8673. PMID 10637363.
  3. ^ Furr BJ (1995). "Casodex: preclinical studies and controversies". Annals of the New York Academy of Sciences. 761: 79–96. doi:10.1111/j.1749-6632.1995.tb31371.x. PMID 7625752.
  4. ^ Furr BJ, Valcaccia B, Curry B, Woodburn JR, Chesterson G, Tucker H (June 1987). "ICI 176,334: a novel non-steroidal, peripherally selective antiandrogen". J. Endocrinol. 113 (3): R7–9. doi:10.1677/joe.0.113R007. PMID 3625091.
  5. ^ Teutsch G, Goubet F, Battmann T, Bonfils A, Bouchoux F, Cerede E, Gofflo D, Gaillard-Kelly M, Philibert D (January 1994). "Non-steroidal antiandrogens: synthesis and biological profile of high-affinity ligands for the androgen receptor". J. Steroid Biochem. Mol. Biol. 48 (1): 111–9. doi:10.1016/0960-0760(94)90257-7. PMID 8136296.
  6. ^ Winneker RC, Wagner MM, Batzold FH (December 1989). "Studies on the mechanism of action of Win 49596: a steroidal androgen receptor antagonist". J. Steroid Biochem. 33 (6): 1133–8. doi:10.1016/0022-4731(89)90420-2. PMID 2615358.
  7. ^ a b Luo, S; Martel, C; LeBlanc, G; Candas, B; Singh, S M; Labrie, C; Simard, J; Belanger, A; Labrie, F (1996). "Relative potencies of Flutamide and Casodex: preclinical studies". Endocrine Related Cancer. 3 (3): 229–241. doi:10.1677/erc.0.0030229. ISSN 1351-0088.
  8. ^ Ayub M, Levell MJ (August 1989). "The effect of ketoconazole related imidazole drugs and antiandrogens on [3H] R 1881 binding to the prostatic androgen receptor and [3H]5 alpha-dihydrotestosterone and [3H]cortisol binding to plasma proteins". J. Steroid Biochem. 33 (2): 251–5. doi:10.1016/0022-4731(89)90301-4. PMID 2788775.
  9. ^ Kemppainen JA, Wilson EM (July 1996). "Agonist and antagonist activities of hydroxyflutamide and Casodex relate to androgen receptor stabilization". Urology. 48 (1): 157–63. doi:10.1016/S0090-4295(96)00117-3. PMID 8693644.