Evaluation of the effects of boswellia elongata resin extracts on chronic obstructive pulmonary disease (COPD) induced in rats

Introduction: Chronic obstructive pulmonary disease (COPD) is a progressive and irreversible respiratory disorder characterized by chronic inflammation, airway remodeling, oxidative stress, immune dysfunction, and extracellular matrix destruction. Although current pharmacological treatments provide symptom control, they do not entirely prevent the structural and molecular progression of the disease. Consequently, there is increasing interest in the therapeutic potential of natural products with anti-inflammatory and antioxidant properties for the treatment of COPD. Boswellia elongata, due to its oleo-gum resin composition, is a promising natural agent capable of modulating inflammatory responses and tissue damage through its bioactive constituents. The present study evaluated the effects of ethanol and methanol extracts derived from Boswellia elongata resin on pulmonary inflammation, tissue damage, and molecular remodeling in an experimental COPD rat model induced by porcine pancreatic elastase (PPE). Materials and Methods: Thirty female Wistar Albino rats were included in the study. The COPD model was induced in all groups except the control group by intratracheal administration of PPE. Animals were assigned to four groups: control, sham (COPD, untreated), Boswellia elongata ethanol extract, and Boswellia elongata methanol extract. The treatment groups received oral administration of the respective extracts for 21 days following elastase exposure. At the conclusion of the experiment, histopathological assessments, flow cytometric analysis of CD3⁺, CD4⁺, and CD8⁺ T lymphocyte subsets, measurement of inflammatory cytokine levels by ELISA, and Western blot analysis of MMP-9, TIMP-1, and F-actin protein expression were conducted on blood and lung tissue samples. Statistical analyses employed appropriate parametric and non-parametric tests, with p ≤ 0.05 considered statistically significant. Results: In the porcine PPE-induced COPD model, the sham group showed significant increases in interstitial inflammation, lymphoid accumulation, and emphysematous changes, confirming the model's establishment (p < 0.001). Blood gas analysis in the sham group showed impaired oxygenation and significant acid-base disturbances compared with controls (p < 0.05). Treatment with the Boswellia elongata ethanol extract resulted in a substantial reduction in interstitial inflammation scores compared with the sham group (p < 0.05). In contrast, the methanol extract group showed less histopathological improvement. Elevated CD3⁺, CD4⁺, and CD8⁺ T lymphocyte ratios observed in the sham group were significantly reduced in both extract-treated groups (p < 0.05). Molecular analyses showed that the increased MMP-9/TIMP-1 ratio in the sham group tended to decrease following extract administration, and F-actin expression, indicative of cytoskeletal integrity, was better preserved, particularly in the ethanol extract group (p < 0.05). Conclusions: The findings indicate that Boswellia elongata resin extracts, especially the ethanol extract, suppressed pulmonary inflammation, modulated immune cell infiltration, and regulated molecular mechanisms associated with extracellular matrix degradation in an experimental COPD rat model induced by PPE. The findings suggest that Boswellia elongata may have regulatory and modulatory effects on multiple biological processes involved in COPD pathophysiology, indicating that this natural agent should be further investigated in experimental and mechanistic studies using different doses, durations, and combination strategies.