Plant Alkaloid Coptisine Shields the Liver From Sepsis by Blocking Cell Death Pathway

Sepsis remains one of the most lethal conditions in intensive care, partly because the liver is highly vulnerable to the inflammatory cascade it triggers. Kupffer cells, the liver's resident macrophages, become hyperactivated during sepsis, driving organ damage through multiple cell death mechanisms. Ferroptosis — an iron-dependent, oxidative form of regulated cell death — has recently emerged as a key contributor to this process, but targeted therapies remain limited.

This study investigated whether coptisine (COP), a natural isoquinoline alkaloid found in medicinal plants such as Coptis chinensis, could protect the liver during sepsis by modulating ferroptosis. Researchers used two mouse sepsis models (cecal ligation and puncture, and LPS injection) alongside LPS+IFN-γ/erastin-stimulated Kupffer cells in vitro to test the compound's effects.

Coptisine significantly reduced liver injury markers, inflammatory cytokines, and ferroptosis indicators in septic mice. In Kupffer cells, it suppressed erastin-induced ferroptosis. Mechanistically, COP was shown to directly bind STAT1 protein, blocking its phosphorylation and downstream activation of the transcription factor IRF1, which in turn restored expression of GPX4 — the master regulator of ferroptosis resistance. Overexpressing STAT1 negated coptisine's protective effects, confirming the pathway specificity.

Clinical data from sepsis patients corroborated these findings, showing elevated phospho-STAT1 and IRF1 alongside reduced GPX4 — mirroring the molecular signature coptisine reverses. This human validation strengthens the translational case for targeting this axis.

While promising, the study is limited by its reliance on preclinical models and a relatively small clinical dataset. The pharmacokinetics, safety profile, and optimal dosing of coptisine in humans remain to be established before clinical application can be considered.