GLP-1's Diverse Roles in Metabolism and Brain Health Explored

Glucagon-like peptide-1 (GLP-1) is a well-established incretin hormone crucial for glucose homeostasis and weight management, with GLP-1 receptor agonists widely used for type 2 diabetes and obesity. Recent research has increasingly highlighted its potential therapeutic effects beyond metabolism, particularly in neurodegenerative diseases like Alzheimer's and Parkinson's. This review aims to provide a comprehensive understanding of GLP-1's multifaceted molecular mechanisms and signaling pathways across both metabolic and neurodegenerative contexts.

The review consolidates evidence demonstrating GLP-1's significant impact on glucose regulation, insulin secretion, and appetite suppression, leading to average weight loss of 5-15% in clinical trials for obesity. It highlights that GLP-1 signaling in the brain contributes to neuroprotection by reducing inflammation, oxidative stress, and improving mitochondrial function, which are critical in Alzheimer's disease and Parkinson's disease. The authors summarize findings where GLP-1 receptor agonists have shown to improve cognitive function and motor deficits in animal models, with some studies reporting a reduction in amyloid-beta plaque formation by up to 40% and a decrease in neuronal apoptosis by 30%. The review underscores that GLP-1's pleiotropic effects are mediated by diverse signaling pathways, including cAMP/PKA, PI3K/Akt, and MAPK cascades, which collectively contribute to its broad therapeutic actions across multiple organ systems.