OBJECTIVE: To assess the effect of Jianpi Huazhuo Tiaozhi granules(JHTG) on oxidative stress damage to macrophages and explore the relationship between the levels of this damage and the nicotinamide adenine dinucleotide phosphate oxidase(NOX)/reactive oxygen species(ROS)-nuclear transcription factor kappa B(NF-κB) signaling pathway.METHODS: Macrophages cultured in vitro were divided into seven groups: control, model control, inhibitor, positive control, 2.5% JHTG, 5% JHTG, and10% JHTG. An oxidative stress injury model was established by stimulating macrophages with oxidized low-density lipoprotein. Cell survival and apoptosis were detected by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide and flow cytometry assays, respectively. Malondialdehyde and superoxide dismutase levels were detected by enzyme-linked immunosorbent assays, while ROS levels were detected using a fluorescence probe. Proteins and m RNAs associated with the NOX/ROS-NF-κB pathway, including NOX4,p22 phox, inhibitor of NF-κB kinase-α(IKK-α), inhibitor of NF-κB kinase-β(IKK-β), and NF-κB were detected by Western blot and PCR, respectively.RESULTS: After JHTG treatment, there were fewer damaged and apoptotic macrophages, while superoxide dismutase levels were elevated. The JHTG-treated groups also showed reduced ROS levels. The molecular changes following JHTG treatment included decreased expression of NOX4 and p22 phox at the protein level and decreased IKK-α,IKK-β, and NF-κB expression at the m RNA level. All of these effects were correlated with the JHTG concentration.CONCLUSION: These results demonstrated that the molecular mechanism underlying the antioxidant activity of JHTG in macrophages is through inhibiting the NOX/ROS-NF-κB pathway.