Melatonin Improves Behavioral and Biochemical Outcomes in a Rotenone-Induced Rat Model of Parkinson's Disease.

Parkinson's disease (PD) is the second most common neurodegenerative disease followed only by Alzheimer's disease and affects millions of people worldwide. Despite the plethora of preclinical and clinical studies, there is currently a paucity of therapeutic agents for PD that can promote neuroprotection. In addition, the therapeutic agents currently available only help with improvement of PD symptoms. Therefore, it is imperative to find new therapeutic avenues for PD patients to minimize the economic and social burden on the concerned families. Rotenone is a frequently used neurotoxin in developing a PD model to aid in understanding the mechanisms of neuronal death. In addition, several studies have investigated the effects of melatonin, a neurohormone that is neuroprotective in various neurological diseases due to its anti-apoptotic, anti-inflammatory, and anti-oxidative properties. Our study investigated the role of melatonin-induced tyrosine hydroxylase (TH) and sensory motor function in a rotenone rat model to determine whether melatonin had any positive effects. Our results revealed that melatonin improves motor function by upregulation of TH in striatum of the brain. In addition, melatonin inhibits the striatal degeneration as shown by histopathological analysis. Therefore, results from the current study provide evidence for melatonin as a promising candidate for effective future therapeutic strategies for PD.