PARKINSON'S DISEASE AND ENDOCANNABINOID SYSTEM: A BRIEF UPDATE

Abstract

In Parkinson's disease, dopaminergic neurons located in the substantia nigra of the brain are destroyed, affecting the patients' motor function. The endocannabinoid system is responsible for controlling neuronal homeostasis and its alteration is related to neurodegenerative diseases, such as Parkinson's. A literature review regarding the relationship between the endocannabinoid system and Parkinson's disease was carried out through a search in the Pubmed database. Complete publications from the last year were included, using 15 papers. Treatment with cannabinoid medications for Parkinson's patients should not be the first choice, being restricted to adjuvant therapy as they are elderly and vulnerable. Cannabis extracts have shown in experimental studies neuroprotective and inflammation modulating actions. Pure cannabidiol is safe, with few side effects. Computational analyzes demonstrated that the binding of cannabidiol to the CB1 and CB2 receptors induced structural changes in them. Levels of CB1 receptors were lower in specific areas of the brain of Parkinson's patients and the decline in these receptors was correlated with worse severity of motor symptoms. Selective CB2 receptor agonists have neuroprotective and immunomodulatory actions, reducing inflammation and the formation of defective proteins. Hyperpolarized current-induced inhibition of CB1 receptors improved muscle stiffness but worsened symptoms of depression and anxiety in animals. The use of exogenous cannabinoids in patients with Parkinson's disease is not yet consolidated, and more clinical studies are needed to confirm the safety of the interaction with the endocannabinoid system.