Ponicidin (Pon), a diterpenoid isolated from Rabdosia rubescens, exhibits a broad range of pharmacological activities, including anti-inflammatory effects. However, its therapeutic potential in Alzheimer's disease (AD), particularly in modulating receptor-interacting protein kinase 1 (RIPK1)-mediated neuroinflammation and necroptosis, remains underexplored. This study aims to investigate the mechanism through which Pon targets RIPK1 to alleviate AD pathogenesis. The interaction between Pon and RIPK1 was confirmed using bio-layer interferometry (BLI) and drug affinity responsive target stability (DARTS) assays. In vitro, the effects of Pon on inflammatory responses and necroptosis were evaluated in BV2 microglial cells (BV2 cells) and HT22 hippocampal neuronal cells (HT22 cells) using Enzyme-linked immunosorbent assay (ELISA), Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), Western blotting (WB), and flow cytometry. In vivo, Pon's therapeutic efficacy was assessed in the 5 × FAD transgenic mouse model of AD through behavioral tests, histological analysis, and biochemical assays. Pon was found to bind RIPK1 with high affinity (K = 135 nM) and enhance RIPK1's resistance to proteolytic degradation. In microglial cells, Pon effectively inhibited the release of pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) by disrupting the RIPK1-janus kinase 1 (JAK1)-signal transducer and activator of transcription 1 (STAT1) signaling pathway. In neurons, Pon suppressed RIPK1-mediated necroptosis by blocking the RIPK1-RIPK3-mixed lineage kinase domain-like protein (MLKL) cascade. Behavioral analysis of 5 × FAD mice revealed that Pon treatment significantly improved cognitive function, reduced amyloid-beta (Aβ) plaque deposition, and alleviated neuroinflammation and necroptosis in the brain. Pon exerts dual neuroprotective effects by targeting RIPK1, mitigating both neuroinflammation and necroptosis, two critical pathological processes in AD. These findings underscore Pon's potential as a disease-modifying therapy for AD and provide a foundation for the clinical development of natural product-derived RIPK1 inhibitors in neurodegenerative diseases. D
