Inhibitory Effects of Gyeongok-go on Lung Injury in a Chronic Obstructive Pulmonary Disease Mouse Model

Background/Objectives: Chronic obstructive pulmonary disease (COPD) is characterized by incomplete recovery of airflow blockage; however, effective therapeutic agents that can prevent lung function deterioration are limited. East Asian herbal treatments have gained attention for their potential benefits in managing COPD. This study aimed to evaluate the inhibitory effects of Gyeongok-go (GOG) on lung injury in a COPD mouse model. Methods: Lipopolysaccharide (LPS)-induced alveolar macrophage (MH-S) cells were treated with GOG (50, 100, 200, and 400 μg/mL), and analyzed using enzyme-linked immunosorbent assay (ELISA). C57BL/6 mice were challenged with cigarette smoke extract and LPS and then treated with vehicle only, dexamethasone (3 mg/kg), or GOG (100, 200, or 400 mg/kg). Bronchoalveolar lavage fluid (BALF) or lung tissues were analyzed using cytospin, ELISA, real-time PCR, flow cytometry, hematoxylin and eosin, and Masson's trichrome staining. Results: Treatment with GOG decreased tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 expression in LPS-challenged MH-S cells. In COPD mice, GOG significantly decreased the elevated numbers of neutrophils, total cells, macrophages, and Gr-1⁺/Siglec-F, Gr-1⁺/CD11b⁺, and CD44^high/CD62L^- cells. It also downregulated the expression of TNF-α, IL-17A, macrophage inflammatory protein-2 (MIP2), and CXC chemokine ligand-1 in BALF. GOG also inhibited the increase in Mip2, Cox-2, and Trpv1 mRNA expression. Moreover, GOG prevented the increase in the number of total cells, neutrophils, Gr-1⁺/Siglec-F, Gr-1⁺/CD11b⁺, CD44^high/CD62L^-, and CD21⁺/CD35⁺/B220⁺ cells in lung tissues. Notably, GOG decreased the severity of lung injury. Conclusions: Overall, these findings indicate that GOG alleviates lung injury, suggesting its potential in the treatment of COPD.