Nobiletin from Xiaoyu Xiezhuo Decoction: Restoring Mitochondrial Dynamics and Alleviating Renal Ischemia-Reperfusion Injury via M1 Macrophage Modulation

Introduction: There have been reports that the traditional Chinese medicine formula Xiaoyu Xiezhuo Decoction (XYXZD) protects against kidney damage. Its possible mechanisms in renal ischemia-reperfusion damage (IRI) are yet unknown, though. Investigating XYXZD's function and possible therapeutic effects on renal IRI is the goal of this investigation. Methods: Liquid chromatography-mass spectrometry and network pharmacology were applied to identify key target genes associated with XYXZD and renal IRI. Molecular docking was employed to forecast the binding affinity of bioactive compounds to these targets. The effects of nobiletin (NOB) on macrophage polarization, inflammatory cytokine production, mitochondrial function, and oxidative stress were evaluated. The impact of NOB on HK-2 mitochondrial dynamics through M1 macrophage polarization was evaluated via the Cell Counting Kit-8 assay, enzyme-linked immunosorbent assay, western blotting, and transmission electron microscopy. Results: Network pharmacology analysis identified matrix metalloproteinase-9 (MMP9) and poly(ADP-ribose) polymerase 1 (PARP1) as key regulatory factors linking macrophage polarization and mitochondrial function. Molecular docking revealed a strong binding affinity between NOB and MMP9. NOB reduced M1 macrophage polarization, along with the downregulation of pro-inflammatory cytokines interleukin-1 beta (IL-1β) and interleukin-6 (IL-6). In HK-2 cells, NOB mitigated mitochondrial dysfunction by modulating M1 macrophage polarization, reducing reactive oxygen species (ROS) production, and restoring mitochondrial dynamics. Conclusion: By preventing M1 macrophage polarization, lowering inflammation, and reestablishing mitochondrial homeostasis in renal tubular epithelial cells, this study showed that NOB has renoprotective benefits. These results provided fresh perspectives on NOB's potential as a treatment for renal IRI.