In a recent study, researchers investigated a drug as a cannabis alternative for Parkinson’s disease.
Parkinson’s disease is a progressive neurodegenerative brain disorder that occurs due to a loss of neurons in the area of the brain that controls movement. These neurons produce the chemical known as dopamine, a neurotransmitter, which is responsible for transmitting signals between neurons in the brain. As the disease progresses, the loss of neurons decreases the availability of dopamine, leading to deficits in movements, which include tremors, bradykinesia (slow movement) and rigidity.
There is currently no cure for Parkinson’s disease, however, some medications help to manage the symptoms. Treatment involves controlling the symptoms with l-dopa or levodopa, a drug used to increase dopamine levels in the brain. However, l-dopa produces a debilitating side-effect known as dyskinesia, which impairs the patient’s voluntary movements. Currently, amantadine is the only drug available that is approved by the FDA to treat dyskinesia in Parkinson’s patients.
Some observational studies suggest that medicinal cannabis can help alleviate symptoms of dyskinesia. But according to researcher, Professor Vissel, there is limited evidence of this, while medicinal cannabis has numerous effects, some of which may not be beneficial in treating Parkinson’s disease. Medicinal cannabis contains some compounds that affect a person’s normal day-to-day activities. Cannabis attaches to brain receptors known as CB1 and CB2, of which CB1 is responsible for causing the psychoactive side-effects of cannabis such as drowsiness and getting high. Some studies suggest developing therapies that target the CB2 receptor may not produce the side-effects associated with CB1 receptor’s activation.
A recent study, published in Neurobiology of Disease, investigated a drug known as HU-308 as a potential cannabis alternative for Parkinson’s disease. The researchers aimed to determine the effects of HU-308 on l-dopa-induced dyskinesia. In this study, male mice, aged seven to eleven weeks old, were given Oxidopamine (6-OHDA) and l-dopa to induce Parkinson’s disease conditions and dyskinesia.
The study reports that HU-308 reduced l-dopa-induced dyskinesia in the mice, suggesting the drug is as effective as amantadine for treating symptoms of Parkinson’s disease. The results also found HU-308 in combination with amantadine was more effective in decreasing dyskinesia than either drug taken alone. The findings suggest HU-308, either taken alone or with amantadine, may be more effective in treating dyskinesia.
The researchers also report that HU-308 decreases inflammation in the brain. The findings suggest that inflammation of the brain may play a role in the development of dyskinesia in Parkinson’s patients, which merits further investigation into therapies that target inflammation.
HU-308 targets only the CB2 receptor, thus providing the medical benefits of cannabis without the psychoactive side-effects. This suggests that the effects of HU-308 will not interfere with the patient’s day-to-day activities and the treatment with this drug could enable them to maintain normal levels of mental sharpness. The findings suggest HU-308 could be a cannabis alternative for Parkinson’s disease, however further study, and eventually, clinical trials in humans will be necessary before this treatment is available.
Written by Ranjani Sabarinathan, MSc
Rentsch P, Stayte S, Egan T, et al. (2019). Targeting the cannabinoid receptor CB2 in a mouse model of l-dopa induced dyskinesia. Neurobiology of Disease. doi: 10.1016/j.nbd.2019.104646
Scientists discover medicinal cannabis substitute for treating Parkinson’s disease. (2019, December 19). Retrieved from https://www.eurekalert.org/pub_releases/2019-12/uots-sdm121919.php
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