Biochanin A inhibits excitotoxicity-triggered ferroptosis in hippocampal neurons

Excitatory neurotransmitter-induced neuronal ferroptosis has been implicated in multiple neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Although there are several reports pertaining to the pharmacological activities of biochanin A, the effects of this isoflavone on excitotoxicity-triggered neuronal ferroptosis remain unclear. In this study, we demonstrate that biochanin A inhibits ferroptosis of mouse hippocampal neurons induced by glutamate or the glutamate analog, kainic acid. Biochanin A significantly inhibited accumulation of intracellular iron and lipid peroxidation in glutamate- or kainic acid-treated mouse hippocampal neurons. Furthermore, biochanin A regulated the level of glutathione peroxidase 4, a master regulator of ferroptosis, by modulating its autophagy-dependent degradation. We observed that biochanin A reduced the glutamate-induced accumulation of intracellular iron by regulating expression of iron metabolism-related proteins including ferroportin-1, divalent metal transferase 1, and transferrin receptor 1. Taken together, these results indicate that biochanin A effectively inhibits hippocampal neuronal death triggered by glutamate or kainic acid. Our study is the first to report that biochanin A has therapeutic potential for the treatment of diseases associated with hippocampal neuronal death, particularly ferroptosis induced by excitatory neurotransmitter.