Protective effect of thymoquinone against testicular torsion induced oxidative injury

Summary We aimed to determine the protective effects of thymoquinone (TQ), against ischaemia–reperfusion (I/R) injury in the testis tissue of rats. Twenty-seven male Wistar albino rats were randomly divided into three equal groups as follows: Group I, sham group; Group II, torsion group; and Group III, torsion + thymoquinone group. The ischaemia period was 2 h, and orchiectomy was performed after 30 min of detorsion. Testis tissue sections were analysed with the terminal transferase mediated dUTP-nick end labelling (TUNEL) assay to determine in situ apoptotic DNA fragmentation. Additionally, Caspase 3 and Bax proteins were analysed immunohistochemically. The superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) activity levels in the testis tissue were also measured. The superoxide dismutase activity and malondialdehyde levels in the torsion group were significantly higher than those of the sham group (P < 0.05). Thymoquinone administration significantly reduced these levels. Torsion significantly increased active-Caspase 3 and Bax expression, which was decreased by thymoquinone. The apoptotic index of the torsion group was significantly higher than that of the control group. However, thymoquinone significantly reduced the apoptotic index (P < 0.05). Our results indicate that thymoquinone plays a protective role in oxidative stress induced ischaemia–reperfusion in the testis tissue of rats.