Beyond insulin: The Intriguing role of GLP-1 in Parkinson's disease

GLP-1 (Glucagon-like peptide 1) serves as both a peptide hormone and a growth factor, is released upon nutrient intake and contributes to insulin secretion stimulated by glucose levels. Also, GLP-1 is synthesized within several brain areas and plays a vital function in providing neuroprotection and reducing inflammation through the activation of the GLP-1 receptor. Parkinson's Disease (PD) is a neurodegenerative illness that worsens with time and is defined by considerable morbidity. Presently, there are few pharmaceutical choices available, and none of the existing therapies are capable of modifying the course of the disease. There is a suggestion that type 2 diabetes mellitus (T2DM) could increase the risk of PD, and the presence of both conditions concurrently might exacerbate PD symptoms and hasten neurodegeneration. GLP-1 receptor (GLP-1R) agonists exhibit numerous implications like enhancement of glucose-dependent insulin release and biosynthesis, suppression of glucagon secretion and gastric emptying. Also, some GLP-1R agonists have received clinical approval for the management of T2DM. Moreover, the use of GLP-1R agonists has demonstrated counter-inflammatory, neurotrophic, and neuroprotective actions in various preclinical models of neurodegenerative disorders. Considering the significant amount of evidence backing the potential of GLP-1R agonists to protect the nervous system across different research settings, this article delves into examining the hopeful prospect of GLP-1R agonists as a treatment option for PD. This review sheds light on combined neuroprotective benefits of GLP-1R agonists and the possible mechanisms driving the protective effects on the PD brain, through the collection of data from various preclinical and clinical investigations.