Cyclosporine a induces testicular injury via mitochondrial apoptotic pathway by regulation of mir-34a and sirt-1 in male rats: The rescue effect of curcumin

Testicular damage contributes to cyclosporine A (CsA) induced male infertility. However, the exact underlying
molecular mediators involved in CsA-induced testis disorder remains unclear. The present study aimed to
characterize the role of mir-34a/sirt-1 in CsA induced testicular injury alone or in combination with curcumin. A
total of twenty-eight male Wistar rats were subdivided into four groups: control (Con), sham, cyclosporine A
(CsA), cyclosporineA + curcumin (CsA + cur). The animals received cyclosporine A (30 mg/kg) and curcumin
(40 mg/kg) for 28 days by oral gavage. At the end of the experiment, CsA administration significantly resulted in
a decrease in testis weight and testis coefficient. The molecular analysis demonstrated that CsA exposure increased
8-OHdg and Nox4 protein contents in the testis tissue. TUNEL staining indicated that CsA caused the
number of apoptotic cells to increase in the testes of male rats. In addition, exposure to CsA resulted in an
increased expression of Bax, and a decreased expresion in that of Bcl-2, with a concomitant up-regulation of the
Bax/Bcl-2, c-Caspase-3/p-Caspase-3 ratio and cytochrome c level. Meanwhile, exposure to CsA increased the
expression of mir-34a and decreased sirt-1 protein level in the testis tissue samples compared to the control
group. Taken together, our findings suggested that CsA can cause damage to testicular germ cells via oxidative
stress and mitochondrial apoptotic pathway, and probably mir-34a/sirt-1 play a crucial role in this process. It
also demonstrates that these negative effects of CsA can be reduced by using curcumin as an antioxidant and
anti-inflammatory agent.