A Novel Weight Loss Mechanism of Hydroxysafflor Yellow A in Obese Mice: Involvement of Immune Inflammation via Prkcd, Btk, and Vav1 Genes in Adipose Tissue.

Introduction: Hydroxysafflor Yellow A (HSYA), known for its anti-inflammatory effects in cardiovascular diseases, has also been shown to reduce adiposity and improve metabolic disorders in diet-induced obese (DIO) mice. However, the molecular mechanisms underlying its anti-obesity effects, particularly whether they are mediated through immune-inflammatory pathways, remain unclear. This study aims to identify the key molecular mechanisms involved in HSYA's anti-obesity action.

Methods: Male C57BL/6J mice were divided into three groups: Standard Feed (SF), High-Fat Diet (HFD), and HFD with HSYA treatment (250 mg/kg/day for 9 weeks). Whole transcriptome sequencing of White Adipose Tissue (WAT) identified Differentially Expressed Genes (DEGs), which were integrated with network pharmacology predictions to identify key molecular targets of HSYA. RT-qPCR in WAT, 3T3-L1 adipocytes, and RAW264.7 macrophages validated the core genes, and molecular docking assessed HSYA's binding affinity with these targets.

Results: HSYA treatment significantly reduced body weight (35.27 ± 1.27g vs. 45.46 ± 1.68g, p < 0.05) and WAT mass (3.38±0.21g vs. 1.86±0.27g, p < 0.05) in DIO mice and ameliorated glucose and lipid metabolism abnormalities. Transcriptome analysis revealed 739 DEGs, with 21 overlapping genes identified between sequencing and network pharmacology analyses. Experimental validation highlighted Prkcd, Btk, and Vav1 as core genes within immune-inflammatory pathways, including chemokine and B cell receptor signaling, which are implicated in obesityrelated inflammation. RT-qPCR confirmed the downregulation of Prkcd, Btk, and Vav1 after HSYA treatment, consistent with transcriptomic findings. Molecular docking analysis demonstrated strong binding affinities between HSYA and VAV1 (-8.5 kcal/mol), BTK (-6.9 kcal/mol), and PRKCD (-6.6 kcal/mol).

Conclusion: HSYA demonstrates the therapeutic potential for obesity by modulating immuneinflammatory pathways in WAT, specifically targeting Prkcd, Btk, and Vav1 in mice. Given its clinical use in cardiovascular disease, these findings suggest that HSYA may offer broader therapeutic benefits, including obesity management, though further studies are needed to clarify the mechanisms and assess its applicability to humans.