Neuroprotective effects of thymoquinone against MDMA-induced neurotoxicity

Abstract

MDMA (3, 4-methylenedioxymethamphetamine) is a psychoactive substance that is associated with neurotoxicity. MDMA exposure to human results in the degeneration of neuronal cells in the hippocampus. Hence, the purpose of this study was to examine the potential of a natural compound known as thymoquinone (TQ) to protect against neuronal damage and memory impairment in rats stimulated by MDMA. The administration of TQ into MDMA-induced neuronal damage rats was carried out in male Sprague Dawley via a 1-week treatment dividing into four groups (n=36, 7-9 per group). The studied groups involved with the treatments comprise i) Control (1 mL/kg saline), ii) MDMA (10 mg/kg MDMA), iii) MDMA+TQ (10 mg/kg MDMA + 40 mg/kg TQ) and iv) TQ control (40 mg/kg TQ). A novel object recognition test (NORT) was carried out to evaluate the memory performance of the rats, followed by a histopathological assessment of the hippocampal dentate gyrus. The histopathology analysis revealed a significant increase in numbers of positive cells by Fluoro-Jade C following the effect of MDMA on neuronal damage (MDMA induced group) compared to control (P<0.05). Next, the TQ treatments observed in MDMA+TQ exhibited a decline in positive cells from Fluoro-Jade C. The index of recognition memory was found to be increased in MDMA+TQ compared to the MDMA alone (P<0.05). This study suggests that the neuronal damage inflicted by MDMA in a rat model has the potential to be treated by TQ.