Dietary lycopene mitigates nonalcoholic steatohepatitis by regulating Nrf2/PPARα-dependent ferroptosis

The global burden of non-alcoholic steatohepatitis (NASH) is on the rise. Researchers recognize inhibiting ferroptosis, a form of cell death leading to iron-dependent oxidative damage, as a promising therapy for treating NASH. Lycopene, a natural antioxidant compound, exhibits various pharmacological properties. However, the anti-NASH efficacy of the dietary recommended concentration of lycopene and the role of lycopene in combating ferroptosis in NASH have remained unclear. Our study investigated lycopene’s impact on ferroptosis in various diet-induced mouse NASH models and corresponding cellular models, unveiling its anti-inflammatory and anti-fibrotic effects. Our findings demonstrated that lycopene notably reduced ferroptosis in methionine- and choline-deficient (MCD) diet-fed mice and a normal mouse hepatocyte cell line (NCTC1469) by restoring balanced ferrous iron levels, lipid reactive oxygen species, and normal mitochondrial morphology. These effects were linked to the regulation of ferroptosis markers glutathione peroxidase 4 (GPX4) and prostaglandin G/H synthase 2. Additionally, lycopene’s anti-ferroptosis action was validated in mice fed a high-fat, high-cholesterol diet and HepG2 cells treated with free fatty acid. Our transcriptomic analysis highlighted peroxisome proliferator-activated receptor α (PPARα) as a primary target of lycopene, crucial for activating the glutathione system because GW6471, a PPARα antagonist, blocked lycopene-induced GPX4 activation. Furthermore, nuclear factor erythroid 2-related factor 2 (Nrf2) played a crucial role in lycopene’s impact on iron metabolism-related proteins ferritin heavy chain 1 and transferrin receptor 1. Notably, when inhibiting PPARα or Nrf2 in MCD diet-fed mice by GW6471 or ML385, lycopene’s protective effects against ferroptosis and NASH progression diminished. These findings underscore the crucial role of PPARα-mediated glutathione system activation and Nrf2-mediated iron metabolism modulation in lycopene’s anti-ferroptosis effects.