[Mechanisms of Platycodon grandiflorum-Sonchus oleraceus combination in alleviating pulmonary nodules in mice via inhibiting macrophage M1 polarization].

This study aimed to investigate the ameliorative effects and underlying mechanisms of the combined use of Platycodon grandiflorum and Sonchus oleraceus on pulmonary nodules in mice. C57BL/6J mice were randomly divided into blank group, model group, positive control group, P. grandiflorum extract group, S. oleraceus extract group, and combination group. The pulmonary nodule model was established by intratracheal instillation of 1×10~9 CFU Cutibacterium acnes for three consecutive days, followed by seven consecutive days of drug administration. Serum amyloid A(SAA) levels were measured, pathological changes in lung tissue were observed, and changes in interleukin(IL)-6, tumor necrosis factor-α(TNF-α), IL-1β, glutathione peroxidase(GSH-PX), superoxide dismutase(SOD), total antioxidant capacity(T-AOC), and malondialdehyde(MDA) levels in lung tissue were evaluated. Additionally, macrophage M1/M2 polarization and activation of the Toll-like receptor 4(TLR4)/myeloid differentiation factor 88(MyD88)/nuclear factor-κB p65 subunit(NF-κB p65) signaling pathway were analyzed. The results showed that all treatment groups ameliorated lung injury in mice with pulmonary nodules. Specifically, the combination group alleviated body weight loss, reduced SAA levels, downregulated the expression of IL-6, TNF-α, and IL-1β, enhanced the activities of GSH-PX, SOD, and T-AOC, decreased MDA accumulation, restored the balance of M1/M2 macrophage phenotypes, upregulated arginase-1(ARG1) levels, suppressed the mRNA expression of inducible nitric oxide synthase(iNOS), TLR4, MyD88, and NF-κB, increased the expression of inhibitor of nuclear factor-κB alpha(IκBα), and downregulated the p-p65/p65 ratio. Meanwhile, compared with the single-herb groups, the combination group demonstrated significant advantages in suppressing inflammatory cytokines and oxidative damage. In conclusion, the combined preparation of P. grandiflorum and S. oleraceus can alleviate pulmonary inflammation and oxidative stress injury and improve pulmonary nodules by inhibiting the NF-κB signaling pathway and suppressing macrophage M1 polarization.