The possible ameliorating effect of Nigella sativa oil on tramadol-induced apoptosis in the motor area of rat cerebral cortex: a histological and immunohistochemical study

Background Tramadol is a centrally active analgesic commonly prescribed for moderate to severe pain. Thymoquinone, the major active component of the Nigella sativa oil, is characterized by its antioxidant properties. Aim of the work This study aimed to demonstrate the histological and p53-immunohistochemical changes induced by tramadol in the rat cerebral cortex and evaluate the potential role of N. sativa oil in the attenuation of these changes. Materials and methods Twenty-four male albino rats divided into three groups were used in this study. Group I was the control group. Group II was given repeated intraperitoneal injections of increasing doses of tramadol of 20, 40, and 80 mg/kg/day on the first, second, and third ten days of the study, respectively. Group III was given oral N. sativa oil 4 ml/kg/day, 30 min before each tramadol injection for 30 days. Paraffin sections of the frontal cortex motor area were prepared and stained with H E and with an immunohistochemical stain using anti-p53 antibody. Results In group II rats, numerous shrunken pyramidal cells with acidophilic cytoplasm and deeply stained pyknotic nuclei were seen. Some of the granular cells appeared as ghosts with margination of chromatin. Homogeneous acidophilic masses containing fragmented deeply stained nuclei and surrounded by clear halos were also observed. The number of p53-positive cells was significantly higher compared with both group I and group III. In contrast, in group III, multiple pyramidal and granular cells appeared normal and the number of p53-positive cells was significantly less compared with group II. Conclusion N. sativa oil and derived thymoquinone ameliorate tramadol-induced apoptosis in the motor area of the rat cerebral cortex.