The Toxic Effects on the Testis of Flutamide vs. Bicalutamide vs. Cyproterone Acetate: An Experimental Rat Study

Abstract

The aim of this study was to investigate the toxic effects on the rat testis of flutamide, bicalutamide, and cyproterone acetate using histopathological methods. Twenty-four male Sprague-Dawley rats were randomly divided into four groups, control (Group 1), flutamide (Group 2), bicalutamide (Group 3), and cyproterone acetate (Group 4). Physiological saline solution or anti-androgens were administered via oral gavage for 14 days. At the end of the study, the testes were harvested for histological toxic effect scoring. The mean histopathology scores were 0 in Group 1, 0.33 ± 0.81 in Group 2, 1.66 ± 1.36 in Group 3, and 2.93 ± 0.98 in Group 4. The histopathology score in Group 4 was significantly higher than that in Group 1 (p = 0.002), but was not significantly different to those in groups 2 and 3 (p = 0.317 and p = 0.028, respectively). No significant difference was also observed between the other groups. Cyproterone acetate, a steroidal antiandrogen, resulted in significant impairment of testis histology relative to the non-steroidal antiandrogens flutamide and bicalutamide. A non-steroidal agent such as flutamide or bicalutamide should therefore be selected if antiandrogen therapy is to be initiated for reasons such as acne, hirsutism, and paraphilias, particularly in young males.

Keywords

• Flutamide
• bicalutamide
• cyproterone acetate
• testis
• histopathology

References

1. 1. Schneider HP. Androgens and antiandrogens. Ann N Y Acad Sci. 2003; 997:292-306.
2. 2. Cornford P, van den Bergh RCN, Briers E, et al. EAU-EANM-ESTRO-ESUR-SIOG Guidelines on Prostate Cancer. Part II-2020 Update: Treatment of relapsing and metastatic prostate cancer. Eur Urol. 2021; 79(2):263-82.
3. 3. Nakagawa H, Ueda T, Ito S, et al. Androgen suppresses testicular cancer cell growth in vitro and in vivo. Oncotarget. 2016; 7(23):35224-32.
4. 4. Chen Y, Zhou Q, Hankey W, Fang X, Yuan F. Second generation androgen receptor antagonists and challenges in prostate cancer treatment. Cell Death Dis. 2022; 13(7):632.
5. 5. Wang RS, Yeh S, Tzeng CR, Chang C. Androgen receptor roles in spermatogenesis and fertility: lessons from testicular cell-specific androgen receptor knockout mice. Endocr Rev. 2009; 30:119–32.
6. 6. Heemers HV, Tindall DJ. Androgen receptor (AR) coregulators: a diversity of functions converging on and regulating the AR transcriptional complex. Endocr Rev. 2007; 28:778-808.
7. 7. Anahara R, Toyama Y, Mori C. Review of the histological effects of the anti-androgen, flutamide, on mouse testis. Reprod Toxicol. 2008; 25(2):139-43.
8. 8. Wang HX, Liu X, Xu CJ, Ma XC, Long JE, Li D. Induction of liver cytochrome P450 1A2 expression by flutamide in rats. Acta Pharmacol Sin. 2005; 26(11):1382-86.

9. 9. Singh AK, Chaurasiya A, Jain GK, et al. High performance liquid chromatography method for the pharmacokinetic study of bicalutamide SMEDDS and suspension formulations after oral administration to rats. Talanta. 2009; 78(4-5):1310-14.
10. 10. 1Gual O, Bozkurt A, Deniz M, Sungur M, Yegen BC. Effect of sex steroids on colonic distension-induced delay of gastric emptying in rats. J Gastroenterol Hepatol. 2004; 19(9):975-81.
11. 11. Creasy DM. Evaluation of testicular toxicology: a synopsis and discussion of the recommendations proposed by the Society of Toxicologic Pathology. Birth Defects Res B Dev Reprod Toxicol. 2003; 68(5):408-15.
12. 12. Cani M, Epistolio S, Dazio G, et al. Antiandrogens as Therapies for COVID-19: A Systematic Review. Cancers (Basel). 2024; 16(2):298.
13. 13. Chen Y, Zhou Q, Hankey W, Fang X, Yuan F. Second generation androgen receptor antagonists and challenges in prostate cancer treatment. Cell Death Dis. 2022; 13(7):632.
14. 14. Ghosh C, Maity R, Roy A, Mallick C. Dose-Dependent Protective Effect of Hygrophila auriculata Seeds on Cyproterone Acetate-Induced Testicular Dysfunction. Reprod Sci. 2023; 30(11):3359-71.
15. 15. Abdulrahman AS, Mustafa IA. Impact of bicalutamide, an anti-androgen on rat testis. ZJPAS. 2019; 31(2):89-100.
16. 16. Aleem M, Padwal V, Choudhari J, Balasinor N, Parte P, Gill-Sharma M. Cyproterone acetate affects protamine gene expression in the testis of adult male rat. Contraception. 2005; 71(5):379-91.
17. 17. Marchetti B, Labrie F. Characteristics of flutamide action on prostatic and testicular functions in the rat. J Steroid Biochem. 1988; 29(6):691-98.
18. 18. Macleod DJ, Sharpe RM, Welsh M, et al. Androgen action in the masculinization programming window and development of male reproductive organs. Int J Androl. 2010; 33(2):279-87.
19. 19. Khursheed A, Minhas LA, Niaz WA. Histomorphometric study of effects of bicalutamide on spermatogenesis in male rats. Pak Armed Forces Med J. 2011; 61:325-29.
20. 20. Tinwell H, Friry-Santini C, Rouquié D, et al. Evaluation of the antiandrogenic effects of flutamide, DDE, and linuron in the weanling rat assay using organ weight, histopathological, and proteomic approaches. Toxicol Sci. 2007; 100(1):54-65.
21. 21. Elzoghby AO, Helmy MW, Samy WM, Elgindy NA. Micellar delivery of flutamide via milk protein nanovehicles enhances its anti-tumor efficacy in androgen-dependent prostate cancer rat model. Pharm Res. 2013; 30(10):2654-63.
22. 22. Sarrabay A, Hilmi C, Tinwell H, et al. Low dose evaluation of the antiandrogen flutamide following a Mode of Action approach. Toxicol Appl Pharmacol. 2015; 289(3):515-24.
23. 23. Floyd MS Jr, Teahan SJ, Fitzpatrick JM, Watson RW. Differential mechanisms of bicalutamide-induced apoptosis in prostate cell lines. Prostate Cancer Prostatic Dis. 2009; 12(1):25-33.
24. 24. Kurtulus FO, Sinanoglu F, Tandogdu Z, Tuzlali P, Fazlioglu A, Cek M. The comparative analysis of medical and surgical castration on rat prostate apoptosis and glandular atrophy. Turk J Urol. 2009; 35(3):164-69.