Qing-Xin-Jie-Yu Granule inhibits ferroptosis and stabilizes atherosclerotic plaques by regulating the GPX4/xCT signaling pathway

Abstract

Ethnopharmacological relevance: Qing-Xin-Jie-Yu Granule (QXJYG) is an integrated traditional Chinese medicine formula used to treat atherosclerotic (AS) cardiovascular diseases. A randomized controlled trial found that QXJYG reduced cardiovascular events and experiments also verified that QXJYG attenuated AS by remodeling the intestinal flora.

Aim of the study: To determine whether QXJYG would attenuate AS and plaque vulnerability by regulating ferroptosis in high-fat diet-induced atherosclerotic ApoE^-/- mice and to investigate the effects of QXJYG on macrophage ferroptosis in RAS-selective lethal 3 (RSL3)-induced J744A.1 cells.

Methods: AS models in ApoE^-/- mice and RSL3-induced ferroptosis in J744A.1 cells were established to measure the protective and anti-ferroptotic effects of QXJYG in vivo and in vitro. The glutathione peroxidase 4 (GPX4)/cystine glutamate reverse transporter (xCT) signal pathway was examined by immunohistochemistry and western blotting.

Results: QXJYG attenuated AS progression and plaque vulnerability. Characteristic morphological changes of ferroptosis in the QXJYG-treated animals were rare. Total iron was significantly lower in the QXJYG group than in the model group (P < 0.05); QXJYG suppressed the lipid peroxidation (LPO) levels (malondialdehyde), enhanced the antioxidant capacity (superoxide dismutase and glutathione), and reduced inflammatory factors (interleukin [IL]-6, IL-1β, tumor necrosis factor-α) associated with ferroptosis. Expression of GPX4/xCT in aorta tissues was remarkably increased in the QXJYG group. QXJYG inhibited ferroptosis in J744A.1 macrophages disturbed using RSL3. The Fe²⁺, LPO, and reactive oxygen species levels were lower in the QXJYG group than in the RSL3 group (P < 0.05). The QXJYG group showed higher expression of the GPX4/xCT signal pathway.

Conclusion: QXJYG inhibits ferroptosis in vulnerable AS plaques partially via the GPX4/xCT signaling pathway.

Keywords: Atherosclerosis; Ferroptosis; GPX4/xCT; Plaque stability; Qing-Xin-Jie-Yu Granule.