Background: Parkinson's disease (PD) is a progressive neurodegenerative disorder. The major causative factors that progress the PD are age, genetic abnormalities, environmental factors and degeneration of dopamine neurons in substantia nigra. PD normally exerts a tonic inhibitory effect on striatal cholinergic interneurons. Anticholinergics act by normalizing the disequilibrium between striatal dopamine and acetylcholine-resulted reduction in tremors.
Objective: This study sought to evaluate the anti-Parkinson potential of dicyclomine in haloperidol (HAL)- and paraquat (PQT)-induced Parkinsonism models in mice.
Materials and methods: Sixty albino mice were divided into six groups (n = 10) for each model. Group I: received distilled water 1 mL/kg, Group II: diseased group received HAL (1 mg/kg) for consecutive 21 days and PQT (2 mg/kg) every three days for three weeks, Group III: treated with sinemet (20 mg/kg), Group IV-VI: received 40, 80 and 160 mg/kg dose of dicyclomine, respectively, for consecutive 21 days. The effect of treatments on spontaneous locomotor activity and motor co-ordination was evaluated by using open field, rotarod, actophotometer and light and dark box tests. Cataleptic behavior was estimated by the block method and triple horizontal bar apparatus. Biochemical markers of oxidative stress and levels of neurotransmitters were estimated.
Results: Findings from this study showed that dicyclomine at highest dose level of 160 mg/kg prevented HAL- and PQT-induced PD through enhancement of antioxidant defense system.
Conclusion: The study concluded that dicyclomine could be the potential drug in the management of Parkinsonism.
Keywords: Haloperidol; catalepsy; dopamine; oxidative stress; paraquet.