A journey through cannabidiol in Parkinson's disease.

Parkinson's disease is a chronic neurodegenerative disorder with no known cure characterized by motor symptoms such as tremors, rigidity, bradykinesia (slowness of movement), and postural instability. Non-motor symptoms like cognitive impairment, mood disturbances, and sleep disorders often accompany the disease. Pharmacological treatments for these symptoms are limited and frequently induce significant adverse reactions, underscoring the necessity for appropriate treatment options. Cannabidiol is a phytocannabinoid devoid of the euphoric and cognitive effects of tetrahydrocannabinol. The study of cannabidiol's pharmacological effects has increased exponentially in recent years. Preclinical and preliminary clinical studies suggest that cannabidiol holds therapeutic potential for alleviating symptoms of Parkinson's disease, offering neuroprotective, anti-inflammatory, and antioxidant properties. However, knowledge of cannabidiol neuromolecular mechanisms is limited, and its pharmacology, which appears complex, has not yet been fully elucidated. By examining the evidence, this review aims to provide and synthesize scientifically proven evidence for the potential use of cannabidiol as a novel treatment option for Parkinson's disease. We focus on studies that administrated cannabidiol alone. The results of preclinical trials using cannabidiol in models of Parkinson's disease are encouraging. Nevertheless, drawing firm conclusions on the therapeutic efficacy of cannabidiol for patients is challenging. Cannabidiol doses, formulations, outcome measures, and methodologies vary considerably across studies. Though, cannabidiol holds promise as a novel therapeutic option for managing both motor and non-motor symptoms of Parkinson's disease, offering hope for improved quality of life for affected individuals.

Cannabidiol improves nonmotor symptoms, attenuates neuroinflammation and favors hippocampal newborn neuronal maturation in a rat model of Parkinsonism.

OBJECTIVE: To investigate the effects of cannabidiol (CBD) on emotional and cognitive symptoms in rats with intra-nigral 6-hydroxydopamine (6-OHDA) lesions. METHODS: Adult male Wistar rats received bilateral intranigral 6-OHDA infusions and were tested in a battery of behavioral paradigms to evaluate nonmotor symptoms. The brains were obtained to evaluate the effects of CBD on hippocampal neurogenesis. RESULTS: 6-hydroxydopamine-lesioned rats exhibited memory impairments and despair-like behavior in the novelty-suppressed feeding test and forced swim test, respectively. The animals also exhibited dopaminergic neuronal loss in the substantia nigra pars compacta (SNpc), striatum, and ventral tegmental area and a reduction of hippocampal neurogenesis. Cannabidiol decreased dopaminergic neuronal loss in the SNpc, reduced the mortality rate and decreased neuroinflammation in 6-OHDA-lesioned rats. In parallel, CBD prevented memory impairments and attenuated despair-like behavior that were induced by bilateral intranigral 6-OHDA lesions. Repeated treatment with CBD favored the neuronal maturation of newborn neurons in the hippocampus in Parkinsonian rats. CONCLUSION: The present findings suggest a potential beneficial effect of CBD on nonmotor symptoms induced by intra-nigral 6-OHDA infusion in rats.