Use of phytocanabinoids in animal models of Parkinson's disease: Systematic review

This systematic review was carried out with the aim of evaluating the use of medicinal Cannabis for the treatment of Parkinson's disease in experimental models. Furthermore, we sought to understand the main intracellular mechanisms capable of promoting the effects of phytocannabinoids on motor disorders, neurodegeneration, neuroinflammation and oxidative stress. The experimental models were developed in mice, rats and marmosets. There was a predominance of using only males in relation to females; in three studies, the authors evaluated treatments in males and females. Drugs were used as inducers of Parkinson's disease: 6-hydroxydopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), lipopolysaccharide (LPS), and rotenone. Substances capable of promoting catalepsy in animals were also used: haloperidol, L-nitro-N-arginine (L-NOARG), WIN55,212-2, and reserpine. The inducing agent was injected stereotaxically or intraperitoneally. The most commonly used treatments were cannabidiol (CBD), Delta-9-tetrahydrocannabinol (Δ-9 THC) and Delta-9-tetrahydrocannabivarin (Δ-9 THCV), administered intraperitoneally, orally, subcutaneously and intramuscularly. The use of phytocannabinoids improved locomotor activity and involuntary movement and reduced catalepsy. There was an improvement in the evaluation of dopaminergic neurons, while in relation to dopamine content, the treatment had no effect. Inflammation, microglial/astrocyte activation and oxidative stress were reduced after treatment with phytocannabinoids, the same was observed in the results of tests for allodynia and hyperalgesia.