Higenamine alleviates abdominal aortic aneurysm by regulating oxidative stress and inflammation against VSMC apoptosis.

BACKGROUND: Abdominal aortic aneurysm (AAA) is a progressive vascular disease marked by apoptosis and phenotypic transition of vascular smooth muscle cells (VSMCs), degradation of the extracellular matrix (ECM), and chronic inflammation. Currently, no pharmacological treatments are available. This work investigated the therapeutic potential and molecular mechanisms of the natural alkaloid higenamine (HG) in AAA.

METHODS: H₂O₂- and LPS-induced VSMCs models were used to assess HG's effects on apoptosis, phenotype, and inflammation. An elastase-induced AAA mouse model evaluated its efficacy in vivo. Network pharmacology, molecular docking, dynamics simulations and cellular thermal shift assays (CETSA) were conducted to elucidate targets and pathways. Mechanistic studies employed Western blot, RT-qPCR, and immunohistochemistry to evaluate the AKT/mTOR and NF-κB/PTGS2 signaling axes.

RESULTS: HG improved VSMCs viability under oxidative stress, reduced ROS and apoptosis, and preserved contractile markers (CNN1, SM22α). In vivo, HG reduced aortic dilation, elastin degradation, and the expression of MMP2 and cleaved caspase-3. Network analysis identified 25 HG-AAA overlapping targets enriched in PI3K-AKT/mTOR pathways, highlighting AKT1 and PTGS2. Molecular docking and CETSA confirmed that HG binds strongly to these proteins. HG enhanced AKT/mTOR phosphorylation in VSMCs in a PI3K-dependent manner. In the LPS model, HG suppressed TNF-α, IL-1β, IL-6, p-NF-κB, and PTGS2 expression, and reduced NF-κB nuclear translocation. IHC and Western blot confirmed that HG restored AKT/mTOR activation and reduced PTGS2 in AAA tissues in a dose-dependent manner.

CONCLUSIONS: HG attenuates AAA progression by activating the AKT/mTOR pathway and inhibiting the NF-κB/PTGS2 axis, offering vascular protection through anti-apoptotic and anti-inflammatory mechanisms. These findings support HG as a promising multi-target natural compound for AAA therapy.