Keap1-Nrf2 Signaling Pathway-Mediated Antioxidant Defense in Neurodegenerative Diseases: Mechanisms and Traditional Chinese Medicine Therapeutic Strategies

Neurodegenerative diseases (NDs) are incurable, progressively disabling disorders marked by sustained neuronal degeneration and loss. Their molecular basis involves intricate regulatory networks, while current therapeutic strategies remain inadequate. Oxidative stress (OS) constitutes a major driver in the initiation and progression of age-related pathologies. Kelch-like enoyl-CoA hydratase-associated protein-1 (Keap1)-Nuclear factor Erythroid 2-related factor 2 (Nrf2) signaling pathway, an essential antioxidant system, exerts protective effects by limiting OS-mediated cellular injury. Extensive evidence demonstrates a close association between Nrf2 signaling and the pathological processes of NDs, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS). Traditional Chinese medicine, characterized by multi-target and multi-pathway regulatory actions of its bioactive constituents, offers distinctive therapeutic potential for NDs. This review provides an integrated analysis of current advances of Nrf2 involvement in NDs and evaluates therapeutic strategies based on traditional Chinese medicine and its active components, with the aim of guiding future clinical translation.