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.

Background/Aim:In the present study, we aimed to compare the potential protective effects of thymoquinone and melatonin by using equivalent dose, on oxidative stress-induced ischemia–reperfusion (IR) injury in the intestinal tissue of rats.Materials and Methods:The study was performed using 32 male Wistar–Albino rats (weighing 180–200 g) randomly divided into four groups: Group I, sham group; Group II, IR group; Group III, IR with melatonin group; and Group IV, IR with thymoquinone group. After laparotomy, ischemia and reperfusion were performed for 60 and 120 min, respectively, on all the groups. Intestinal tissue sections were stained using routine histological methods and examined under the light microscope. In addition, the sections were immunohistochemically stained using the TUNEL method for determination of apoptosis. Superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity, and malondialdehyde (MDA) levels in the intestinal tissue were also measured.Results:The IR group had significantly elevated tissue SOD activity, GSH-Px activity, and MDA levels compared with the sham group. Administration of thymoquinone and melatonin efficiently reduced these increases. Statistically significant number of apoptotic cells was observed in the intestinal tissue of IR group rats compared with the sham group. Treatment with thymoquinone and melatonin markedly reduced the number of apoptotic cells.ConclusionThe effects of melatonin and thymoquinone on IR-induced oxidative stress in rat intestines were similar. Our findings suggest that melatonin and thymoquinone protect against IR-induced injury to intestinal tissues.