Tetramethylpyrazine inhibits neuronal ferroptosis after intracerebral hemorrhage by regulating ferritinophagy.

BACKGROUND

Emerging evidence suggests that ferroptosis, triggered by iron overload, plays a significant role in the resultant brain damage following intracerebral hemorrhage (ICH). Tetramethylpyrazine (TMP) is an alkylpyrazine bicyclic heterocyclic compound and a potent volatile aroma compound found in fermented foods, vinegar, cocoa, and traditional Chinese medicine. It has been extensively employed in the management of ICH; however, its precise mechanism of action remains to be elucidated.

PURPOSE: Current work aims to clarify the effects of TMP on neuronal ferritinophagy and ferroptosis in ICH.

METHODS

Collagenase VII was used to perform stereotactic injections into the brain of C57BL/6 mice to establish an ICH model. The therapeutic efficacy of TMP in mice with ICH was assessed using behavioral tests and hemorrhage volume measurement. The effect of TMP on neuronal ferroptosis and ferritinophagy following ICH was examined using in vivo and in vitro models.

RESULTS

TMP significantly enhanced neurological functions and reduced hemorrhagic volume following ICH. It downregulated ferritinophagy markers, including nuclear receptor coactivator 4 (NCOA4) and microtubule-associated protein light chain 3 (LC3), while upregulating Sequestosome-1 (P62) and ferritin levels. Concurrently, TMP decreased malondialdehyde (MDA) and reactive oxygen species (ROS) levels and increased the expression of glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1), indicating a potent anti-ferroptotic effect.

CONCLUSION

TMP protects neurons against ferroptosis after ICH by inhibiting NCOA4-mediated ferritinophagy, an effect associated with activation of the PI3K/AKT pathway. These findings identify the natural product TMP as a promising candidate for ICH therapy and reveal novel mechanistic insights into the autophagy-ferroptosis axis.