[Effect of Spearmint oil on inflammation, oxidative alteration and Nrf2 expression in lung tissue of COPD rats].

Objective: To investigate the effect of Spearmint oil on inflammation, oxidative alteration and Nrf2 expression in rats with chronic obstructive pulmonary disease(COPD).

Methods: COPD model was induced by intratracheal instillation of Klebsiella pneumonia and lipopolysaccharide (LPS) for 12 weeks in rats, and COPD rats were treated with Spearmint oil for 3 weeks. After COPD was induced, the pathological changes, changes in leucocyte number in blood and bronchoalveolar lavage fluid (BALF), MDA in lung homogenate and Nrf2 expression were observed. The effects of Spearmint oil on these changes were determined.

Result: Spearmint oil 100 mg*kg(-1)significantly reduced leucocyte numbers in BALF, and attenuated bronchiolitis, pulmonary interstitial inflammation and inflammation cell infiltration. Spearmint oil 30-300 mg*kg(-1)decreased the destruction of pulmonary alveolus and the thickness of bronchioles walls, and inhibited goblet cell proliferation. Spearmint oil significantly reduced MDA in lung homogenate, and decreased the expression of Nrf2 protein in lung tissues.

Conclusion: Spearmint oil has protective effect on lung injury in COPD rats, since it improves pulmonary inflammation,oxidative alteration, and enhances Nrf2 protein expression.