Hederagenin ameliorates ferroptosis-induced damage by regulating PPARα/Nrf2/GPX4 signaling pathway in HT22 cells: An in vitro and in silico study.

Background: Hederagenin (HG), derived from ivy seeds, is known to offer protection against Alzheimer's disease (AD). However, the specific molecular pathways through which it counters ferroptosis-induced neurotoxicity are not fully elucidated. This investigation seeks to delineate the processes by which HG mitigates neurotoxic effects in HT22 cells subjected to glutamate (Glu)-induced ferroptosis.

Methods: HT22 cell ferroptosis was prompted by Glu exposure. Cell viability was assessed using CCK-8 and LDH assays, while Fe fluorescence and assays of iron-related proteins served to gauge intracellular Fe concentrations. Evaluations of mitochondrial structure and functionality employed JC-1 staining and transmission electron microscopy. Assessments of ROS, lipid peroxidation, MDA, 4-HNE, and the GSSG/GSH ratio were conducted to ascertain HG's antioxidative efficacy. The expression of proteins within the PPARα/Nrf2/GPX4 pathway was quantified via western blotting, with molecular docking (MD), and molecular dynamics simulations (MDS) used to explore protein interactions.

Results: HG diminished the cellular toxicity triggered by Glu in HT22 cells, lowered Fe within cells, and rejuvenated mitochondrial morphology and performance. Concurrently, it modulated proteins critical to Fe metabolism, diminished ROS and lipid peroxidation, and elevated GSH/GSSG ratios. Enhanced PPARα/Nrf2/GPX4 protein levels were corroborated by western blot results. Furthermore, molecular docking revealed favorable binding of HG to the proteins PPARα, Nrf2, and GPX4, with binding energies of -7.751, -7.535, and -7.414 kcal/mol, respectively. MDS confirmed robust interactions between HG and these pivotal targets.

Conclusion: The evidence suggests that HG effectively mitigates Glu-induced ferroptosis in HT22 cells by activating the PPARα/Nrf2/GPX4 signaling pathway. These findings endorse HG's potential as a nutritional adjunct for AD management.