Dingxin Recipe III resolves atherosclerotic inflammation via revitalizing Regulatory T cell lineage fidelity associated with fatty acid oxidation metabolic reprogramming.

BACKGROUND: Atherosclerosis is fundamentally a pathology of unresolved inflammation perpetuated by the collapse of Regulatory T cell (Treg)-mediated tolerance. Emerging evidence indicates that Treg functional integrity is intrinsically dictated by mitochondrial fatty acid oxidation (FAO), a metabolic checkpoint often compromised under systemic metabolic stress. Current lipid-lowering therapies, such as statins, often fall short in correcting this maladaptive immunometabolic defect and may introduce collateral metabolic perturbations.

PURPOSE: This study aimed to elucidate the immunometabolic therapeutic mechanism of Dingxin Recipe III (DXR III) in ameliorating atherosclerosis.

METHODS: We employed an integrated systems pharmacology strategy-combining serum pharmacochemistry, multi-omics profiling, and extensive high-dimensional flow cytometry-to elucidate the therapeutic mechanism of DXR III, a traditional Chinese herbal formula in an in vivo study. ApoE-/- mice were fed with a high-fat diet for 16 weeks, and treated intragastrically with DXR III (at doses of 6.5 g/kg/day and 13 g/kg/day) or Simvastatin (positive control, 5 mg/kg/day) over the last 12 weeks.

RESULTS: DXR III treatment effectively attenuating atherosclerotic progression. Serum pharmacochemistry identified 254 prototypical absorbed constituents, including Tanshinone I (a potential Peroxisome Proliferator-Activated Receptor Gamma agonist), as bioactive candidates. Multi-omics analysis revealed that DXR III modulated the metabolic environment, coinciding with restored FAO flux. This shift was associated with a favorable metabolic niche characterized by increased FAO substrates, which correlated with the rescue of Treg differentiation and phenotypic stability. Specifically, DXR III facilitated the redistribution of Tregs from the spleen to plaque sites and significantly inhibited their trans-differentiation into Th1-like or Th17-like phenotypes. Conversely, Simvastatin treatment, despite lowering lipids, resulted in peripheral Th17 accumulation and failed to alleviate hyperglycemia. In contrast, DXR III maintained Th17 homeostasis-abolishing the pathogenic non-classical Th17 subset-and exerted dual-regulatory effects on both lipid and glucose metabolism.

CONCLUSION: DXR III ameliorates atherosclerosis, a process closely associated with the modulation of the FAO metabolic checkpoint to correct the immune imbalance driving plaque progression. By rescuing the Treg differentiation, functional integrity, and phenotypic fidelity while avoiding the immunological trade-offs associated with Th1/Th17, DXR III represents a promising candidate for comprehensive cardiovascular protection.