Aloe-emodin attenuates Aβ_25-35-induced HT22 cell pyroptosis via inhibiting NLRP3 inflammasome pathway

Neuronal death in Alzheimer's disease (AD) is closely associated with NLRP3 inflammasome-mediated pyroptosis. This study aimed to investigate the protective effects of Aloe-emodin (AE) in an AD cellular model and to explore the underlying mechanisms involving the NLRP3 inflammasome pathway. Molecular docking simulations predicted strong binding affinities between AE and key pyroptosis-related proteins (NLRP3, ASC, Caspase-1, GSDMD), with the highest affinity observed for NLRP3. In an Aβ₂₅₋₃₅-induced AD cellular model, AE (6 µM) significantly enhanced cell viability and alleviated pyroptotic morphological changes, including cellular swelling and rupture. EdU staining and immunofluorescence analysis further revealed that AE promoted HT22 cell proliferation and reduced Aβ deposition. Moreover, assessments of plasma and mitochondrial membrane integrity, via Hoechst 33,342/PI staining and mitochondrial permeability transition pore (MPTP) assay, respectively, revealed that AE treatment reduced the population of PI-positive cells and suppressed MPTP opening. Western blot, immunofluorescence, and ELISA analyses consistently demonstrated that AE downregulated the expression of pyroptosis-related proteins (NLRP3, ASC, Caspase-1, GSDMD, GSDMD-N) and suppressed the release of inflammatory cytokines (IL-1β, IL-18, IL-6, TNF-α). The inhibitory effect of AE on the pyroptosis pathway was comparable to that of the specific NLRP3 inhibitor MCC950. These results suggest that AE exerts neuroprotective effects in the AD cellular model by inhibiting NLRP3 inflammasome activation, thereby blocking Caspase-1 and GSDMD-N activation, attenuating neuronal pyroptosis, reducing inflammatory responses, and mitigating Aβ-induced pathological damage. Collectively, these findings identify AE as a promising therapeutic candidate for AD.