Protective effects of tadalafil against cisplatin-induced spermatogenic dysfunction

Cisplatin (CDDP) is an effective anticancer drug for the treatment of malignant tumors, such as lung cancer, bladder cancer, and testicular cancer. However, oligozoospermia and azoospermia after administration of CDDP are clinical problems. One of the testicular toxicities of CDDP is known to cause oxidative stress. Tadalafil has been reported to exhibit antioxidant effects and is widely used in clinical practice to treat benign prostatic hyperplasia and erectile dysfunction. Rho-kinase α (ROCK2) regulates cell migration and apoptosis and has been reported to be involved in CDDP-induced nephrotoxicity. The excessive expression of ROCK2 is known to cause oxidative stress.

The objective of the current study was to test the effect of tadalafil on the testicular toxicity of CDDP.

Thirty-two rats were used and divided into the following four groups. (1) The control group (CONT), treated with saline on day 1 and saline and dimethyl sulfoxide (DMSO) on days 1-10 intraperitoneally (i.p.) (2) The Tadalafil Group (TAD), treated with saline on day 1, and 0.4 mg/kg tadalafil on days 1-10 i.p. (3) The CDDP group (CD), treated with 7 mg/kg CDDP, saline, and DMSO on days 1-10 i.p. and (4) The CDDP + TAD group (CDT) was treated with 7 mg/kg CDDP on day 1, and 0.4 mg/kg tadalafil on days 1-10 i.p. Testes and epididymides samples were collected on day 11. Biochemical and pathological analyses and quantitative polymerase chain reaction were performed on the excised specimens.

CDDP treatment resulted in testicular atrophy, decreased sperm concentration, and atrophy of seminiferous tubules as observed from the testicular histology. Increased apoptosis of seminiferous tubules, oxidative stress, and ROCK2 mRNA expression were observed after CDDP treatment. Treatment with tadalafil improved these adverse effects.

Tadalafil is a potential drug for reducing CDDP-induced spermatogenic dysfunction. The antioxidant effect of tadalafil may be partly responsible for this phenomenon. ROCK2 and oxidative stress markers may be involved in the possible antioxidant effects of tadalafil. Tadalafil may be considered as one of a treatment option for reducing spermatogenic dysfunction after administration of CDDP.