Banxia Xiexin Decoction attenuates atherosclerosis by reducing mitochondrial damage via the p62/SLC7A11/GPX4 pathway

Traditional Chinese Medicine (TCM) has demonstrated multiple therapeutic advantages in the management of atherosclerosis (AS), a progressive vascular disease characterized by lipid accumulation and chronic arterial inflammation. Among the various TCM formulations, Banxia Xiexin Decoction (BXD) is a classical prescription first documented in Zhang Zhongjing's "Treatise on Cold Damage" during the Eastern Han Dynasty. This decoction is grounded in the principle of "pungent opening and bitter descending," which posits that pungent herbs disperse stagnation while bitter herbs promote the downward clearance of pathogenic factors. BXD has been historically applied to treat Xiong Bi (chest stuffiness and pain), a TCM syndrome clinically considered to correspond to coronary heart disease (CHD)-the primary clinical outcome of atherosclerosis. Although BXD effectively alleviates chest discomfort and pain, the precise molecular mechanisms underlying its anti-atherosclerotic effects remain incompletely understood.

This study aimed to preliminarily determine whether BXD attenuates atherosclerosis by improving lipid metabolism, inflammatory responses, autophagy, oxidative stress, and ferroptosis, while also elucidating the underlying mechanisms involved.

In this study, we utilized a high-fat diet and vitamin D₃-induced atherosclerotic rat model to evaluate the effects of BXD administered intragastrically at low, medium, and high doses (0.41, 0.82, and 1.64 g mL^-1) over a period of 12 weeks. The bioactive components of BXD were characterized using UPLC-Q-TOF-MS/MS. We measured serum lipid profiles, biochemical indices, and inflammatory cytokines, including GSH, TNF-α, and IL-6. Additionally, we assessed histological changes using HE, Masson, and Oil Red O staining, as well as ultrastructural alterations observed via TEM. Western blotting and quantitative PCR were employed to evaluate the expression of p62, SLC7A11, GPX4, and other markers associated with ferroptosis and autophagy.

UPLC-Q-TOF-MS/MS preliminarily identified a total of 1775 compounds from BXD samples, among which multiple bioactive ingredients were characterized. Serum analysis indicated that BXD reduced TC, TG, and LDL-C, elevated HDL-C, alleviated liver, renal, and myocardial injury, and suppressed inflammatory TNF-α and IL-6. HE, Oil Red O, and Masson staining revealed that BXD relieved aortic lipid plaque deposition, inflammatory infiltration, and collagen fibrosis. TEM exhibited BXD restored damaged mitochondrial ultrastructure in the aorta and liver. Western blotting and qPCR verified that BXD regulated the p62/SLC7A11/GPX4 ferroptosis pathway, elevated autophagy-related LC3B, Beclin-1, and ATG5, while downregulating ferroptosis promoters ACSL4 and PTGS2.

This study reveals, for the first time, a mechanism by which BXD ameliorates atherosclerosis through the regulation of the ferroptosis-autophagy axis, thereby providing an experimental basis for its clinical application.