Protective effect of curcumin in cisplatin-induced oxidative injury in rat testis: mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways.

Background: The aim of this study was to investigate the cellular/biochemical mechanisms by which cisplatin (CIS) causes testicular toxicity. We evaluated the role of inducible nitric oxide synthase (iNOS) expression, mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-kB) activation in the pathogenesis of testicular damage induced by CIS, and investigated the effects of curcumin (CMN) against CIS-induced testicular injury in rats.

Methods: Rats were divided into five equal groups: (1) control, (2) CIS, (3) CMN, (4) CIS + CMN and (5) CIS + corn oil. After the treatment, body and testicular weights, and plasma testosterone levels were observed, along with the biochemical, histopathological and immunohistochemical changes in testes.

Results: Testicular weight, plasma testosterone levels, activities of glutathione peroxidase (GSH-Px) and glutathione (GSH) levels significantly decreased, whereas the level of malondialdehyde (MDA) and nitric oxide (NO) significantly increased with CIS compared with the controls. A significant increase in plasma testosterone levels, GSH levels and GSH-Px activity, and a decrease in MDA and NO levels in testicular tissue were observed with CIS + CMN compared with that with CIS alone. There was marked staining for iNOS, MAPK/p38 and NF-kB/p65 expression with CIS compared with the control and CIS + CMN groups. CIS caused irregular seminiferous tubules, reduction of seminiferous epithelial layers, significant maturation arrest and perivascular fibrosis. CMN administration to CIS-treated rats significantly prevented these histopathologic changes.

Conclusions: MAPK and NF-kB activation have a significant role in CIS-induced testicular toxicity. CMN has a strong potential for use as a therapeutic adjuvant in CIS gonadotoxicity.