Araloside A Induces Raf/MEK/ERK-Dependent Autophagy to Mitigate Alzheimer's and Parkinson's Pathology in Cellular and C. elegans Models.

Alzheimer's disease (AD) and Parkinson's disease (PD) are characterized by pathological protein aggregation and oxidative stress, leading to progressive neurodegeneration. Enhancing autophagy, the primary intracellular pathway for clearing misfolded proteins, represents a promising therapeutic strategy. In this study, we identify Araloside A (ARA), a triterpenoid saponin derived from Aralia elata, as a potent autophagy inducer that alleviates AD- and PD-related pathology. In neuronal cell models, ARA promotes autophagosome formation, increases LC3-II and Beclin-1 levels, and decreases P62, indicating enhanced autophagic activity. Mechanistic investigations reveal that ARA directly binds to Raf, MEK, and ERK proteins and activates autophagy in a Raf/MEK/ERK-dependent manner. This activation facilitates the clearance of APP, total Tau, phosphorylated Tau, and α-synuclein, thereby reducing cytotoxicity. Furthermore, in transgenic Caenorhabditis elegans models of AD and PD, ARA treatment alleviates protein aggregation and behavioral deficits via ERK-dependent autophagy. Together, these findings identify ARA as a natural compound that enhances autophagic clearance of neurotoxic aggregates via Raf/MEK/ERK pathway activation, offering promising therapeutic insights for neurodegenerative proteinopathies.