Therapeutic Evaluation of Thymoquinone in the Intracerebroventricular Injection of L-Cysteine Induced Vascular Dementia in Rats

Introduction: Worldwide, dementia is one of the leading causes of death. The major type of dementia disorders is Alzheimer disease (AD) and vascular dementia (VaD). The progress of VaD is due to the lack of blood flow; and the accumulation of metabolic neurotoxin in the nervous system. In the present study, VaD was induced by intracerebroventricular injection of L-Cysteine (L-Cys) in rats. Methods: Thymoquinone (TQ; 5 and 10 mg/kg; p.o.) was administered for 5 consecutive days. Donepezil (10 mg/kg; p.o. 5 consecutive days) was used as a reference control. Neurocognitive functions were tested at different time intervals. Furthermore, L-Cys induced biochemical changes were also estimated in plasma and hippocampus tissue samples. Results: Treatment of TQ ameliorates the L-Cys induced cognitive impairments along with biochemical changes as similar to donepezil treatment. Conclusion: Hence, the TQ may be a newer medicine for dementia disorder due to its anti-oxidant, anti-lipid peroxidative, anti-inflammatory actions; regulation of cholinergic neurotransmission; and reduction of metabolic accumulation of neurotoxin.