Semaglutide Neuroprotection Study - PubMed
Zhang et al./PubMed/2020
Why It Matters
This paper caught my attention because it tests a drug millions are already taking for diabetes and weight loss — and finds it might protect the brain in Parkinson's disease. The researchers used MPTP, a toxin that selectively kills the same dopamine neurons that die in human Parkinson's, making this more relevant than typical mouse studies. Important caveat: this is mouse data only, though the authors mention a human trial was starting (this was published in 2020, so that trial data may now exist).
Key Findings
- Semaglutide at 25 nmol/kg every other day for 30 days improved motor function and preserved tyrosine hydroxylase levels (the enzyme dopamine neurons need) in MPTP-poisoned mice
- Both semaglutide and liraglutide reduced alpha-synuclein accumulation — the toxic protein clumps that are a hallmark of Parkinson's disease
- The drugs reduced brain inflammation, decreased lipid peroxidation (a marker of oxidative damage), and increased GDNF, a growth factor that specifically protects dopamine neurons
- Semaglutide showed stronger effects than liraglutide across most outcomes despite being dosed every other day versus daily — likely due to its longer half-life in the body
- The drugs appeared to work through multiple mechanisms: reducing mitochondrial stress, lowering inflammation, and boosting protective growth factors
Read the Paper↗PMID: 30741689