The AMPK/GDF15 Axis: A Novel Target for the Neuroprotective Effects of Metformin in Ischemic Stroke

Metformin is an anti-diabetic drug used in the management of type 2 diabetes (T2D). Metformin has different pleiotropic effects, such as anti-inflammatory, antioxidant, antithrombotic, and vasculoprotective. Metformin has neuroprotective effects against neurodegenerative diseases and ischemic stroke. Conversely, metformin may exacerbate the pathogenesis of ischemic stroke. This controversial point may be related to the impact of metformin on the different signaling pathways, such as AMP-activated protein kinase (AMPK) and growth differentiation factor 15 (GDF-15). Many studies have reported the effect of metformin on ischemic stroke, with AMPK signaling only. However, little has been explored about the impact of metformin on the GDF-15 signaling in ischemic stroke. Accordingly, this review aims to discuss the role of metformin in the neuropathology of ischemic stroke regarding the AMPK and GDF-15 signaling pathways.