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Intranasal insulin: promising preclinical findings for Parkinson’s
Original article: Intranasal delivery of low-dose insulin ameliorates motor dysfunction and dopaminergic cell death in a 6-OHDA rat model of Parkinson’s Disease Neuroscience Letters : 2020
A study in a rat model of Parkinson’s has shown that low dose insulin administered through the nose can improve movement and help protect dopaminergic neurons from damage.
Why is it important?
- Novelty 70% 70%
- Proximity 60% 60%
- Deliverability 70% 70%
For individuals who do not like needles or have trouble swallowing pills, intranasal delivery of therapeutics represents an efficient means of accessing the brain. This timely pre-clinical study provides a strong case for support for following up a clinical trial that recently reported results (https://www.ncbi.nlm.nih.gov/pubmed/31022213). In that small clinical study, 16 people were assessed over 4 weeks for daily intranasal delivery of insulin, and the treatment was found to be well tolerated. Based on these new results from rodents, a larger clinical trial assessing efficacy seems to be warranted.
The team separated 39 rats into three groups. Two groups of rats underwent surgery to deliver a toxin directly into the brain, in order to mimic Parkinson’s. They were compared to a third group that only received the surgery required to deliver the toxin, but not the toxin itself, to check that the animal model was successful in recreating many of the symptoms caused by Parkinson’s. In the two animal model groups, rats were treated intranasally either with a) plain saline, or b) with a low dose of insulin.
After 4 weeks of daily (Monday through Friday) dosing, all the animals underwent behavioural testing and the researchers also checked on the survival of dopamine neurons. As expected, the toxin caused movement problems and reduced the number of dopamine neurons in the group that received the toxin and daily saline, compared to the group that only had the sham surgery and saline. The intranasal insulin group performed better on two tests of balance and movement, and also had improved dopamine neuron survival.
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