Berberine Improves Ox-LDL-Induced Macrophage Efferocytosis Dysfunction and Alleviates Inflammation via the PPAR<i>γ</i>/LXR<i>α</i> Pathway

To investigate the mechanisms by which berberine (BBR) improves macrophage efferocytosis dysfunction and alleviates inflammation induced by oxidized low-density lipoprotein (ox-LDL), a macrophage efferocytosis dysfunction model was established by inducing RAW264.7 cells with ox-LDL. This model was employed to assess the enhancing efferocytosis and anti-inflammatory effects of BBR in vitro. Flow cytometry was used to detect the efferocytosis function of RAW264.7 cells, while enzyme-linked immunosorbent assay (ELISA) measured inflammatory factor levels. Reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting were utilized to assess mRNA and protein expression levels of the PPARγ/LXRα axis and efferocytosis-related molecules. Results showed that efferocytosis significantly increased in RAW264.7 cells following protective intervention with BBR, evidenced by markedly higher expression of efferocytosis-related molecules GAS6, MerTK, and ABCA1 compared to the ox-LDL group. Additionally, BBR reduced the production of pro-inflammatory cytokines, enhanced the release of pro-resolving mediators, and mitigated inflammation. BBR enhanced efferocytosis by upregulating the expression of PPARγ/LXRα proteins and mRNA. In the presence of the PPARγ inhibitor (GW9662) and the LXRα inhibitor (GSK2033), levels of GAS6, MerTK, and ABCA1, as well as the expression levels of PPARγ/LXRα proteins and mRNA, were significantly lower compared to the BBR group. Furthermore, the inhibition of efferocytosis and production of anti-inflammatory cytokines were markedly weaker in the BBR+GW9662 and BBR+GSK2033 groups. These findings suggest that BBR exerts effects through the PPARγ/LXRα pathway, enhancing efferocytosis, regulating macrophage phenotype, inhibiting pro-inflammatory cytokine production, promoting pro-resolving mediators release, and demonstrating anti-atherosclerosis effects.