Effects of Astragalus membranaceus injection at Zusanli (ST36) acupoint on lung cancer with COPD

This study investigates the antitumor effects and immunomodulatory mechanisms of Astragalus membranaceus (AM) injection at Zusanli (ST36) acupoint in a mouse model of lung cancer with chronic obstructive pulmonary disease (LC-COPD). Mice were divided into LC-COPD and lung cancer-only groups, each further subdivided into model, AM, cisplatin (DDP), and AM + DDP subgroups. Tumor growth, lung metastasis, and survival were assessed. Expression of PD-1 and TIM-3 in tumor tissues was evaluated by immunohistochemistry and Western blot. The proportions of PD-1⁺ and PD-1⁺ TIM-3⁺ CD8⁺ and CD4⁺ T cells were analyzed by flow cytometry. AM injection at Zusanli alone inhibited tumor weight to a similar extent in both the LC-COPD and lung cancer-only groups, but conferred greater inhibition of pulmonary metastasis and prolonged survival only the LC-COPD group. Combining this therapy with DDP further reduced tumor weight and metastasis and extended survival, outperforming either single treatment in the LC-COPD group only. AM intervention downregulated PD-1 and TIM-3 expression in tumor tissues and reduced the proportions of PD-1⁺ and PD-1⁺ TIM-3⁺ CD8⁺ and CD4⁺ T cells. These immunomodulatory effects were greater in the LC-COPD group. In the LC-COPD model, AM injection at Zusanli significantly downregulated PD-1 and TIM-3 expression and alleviated T cell exhaustion. This may explain why LC-COPD derives greater benefit from this therapy. The combination of this therapy with DDP enhanced anti-tumor efficacy, suggesting its promise as an effective treatment strategy for LC-COPD.