Apigenin ameliorated ferroptosis induced by high-fat-diet via suppressing lysosome iron efflux in hepatocytes

Recently, ferroptosis has been found as a kind of cell death defined by the accumulation of reactive oxygen species (ROS) depending on iron and lipid peroxidation. A high-fat diet (HFD) may have the potential to trigger ferroptosis, resulting in liver injury. Apigenin is a natural flavonoid widely present in fruits and vegetables. In the study, we found HFD-fed could increase the iron level, malondialdehyde level, the expression of acyl-CoA synthetase long-chain family member 4 and transferrin receptor 1, decrease the glutathione level, the expression of glutathione peroxidase 4, ferritin heavy chain and ferroportin in C57BL mice. Further, conventional morphological hallmarks of ferroptosis were observed using transmission electron microscopy. However, apigenin treatment eliminated these harmful effects. Similar to in vivo results, we found apigenin could alleviate palmitic acid (PA)-induced ferroptosis in AML12 cells. Further, we found apigenin could promote PA-inhibited mitophagy and decrease intracellular ROS accumulation, thereby restoring PA-induced lysosomal membrane permeabilization (LMP). In the further mechanism study, we added relevant inhibitors. The results showed that apigenin could clear PA-induced damaged mitochondria through mitophagy, and reduce the leakage of free iron ions in lysosomes into the cytoplasm by restoring the permeability of lysosomes. Therefore, apigenin could inhibit ferroptosis induced by HFD and PA via suppressing lysosome iron efflux by reducing LMP and activating mitophagy in mice and AML12 cells.