Quantitative Pulmonary Administration of Essential Oil from Alpiniae Zerumbet Fructus for Treatment of Emphysema / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the effect of quantitative pulmonary administration of the essential oil from Alpiniae Zerumbet Fructus （EOAZF） on porcine pancreatic elastase （PPE）-induced emphysema in mice and explore its action mechanism. MethodC57BL/6J mice were randomly divided into five group， namely the control group， model group， low- （2 mg·kg-1） and high-dose （20 mg·kg-1） EOFAZ groups， and positive control dexamethasone （DEX，1 mg·kg-1） group. The mice were treated with pulmonary administration of PPE using a microsprayer aerosolizer， once every seven days， for four times in total， for inducing emphysema. During this period， EOFAZ were administered with a quantitative microsprayer aerosolizer once every other day， for 14 times. The lung tissues were then sampled and stained with hematoxylin-eosin （HE） for observing the morphological changes and calculating the pulmonary mean linear intercept （MLI）. The concentrations of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， and interleukin-6 （IL-6） in the plasma were determined by enzyme-linked immunosorbent assay （ELISA）. The activities of superoxide dismutase （SOD） and catalase （CAT） and the content of malondialdehyde （MDA） in the lung tissues were measured using the biochemical assay kits. The protein expression levels of nuclear factor E2-related factor 2 （Nrf2）， quinone oxidoreductase1 （NQO1）， B cell lymphoma-2 （Bcl-2）-associated X protein （Bax）， and Bcl-2 in lung tissues were detected by Western blot. ResultThe results of lung morphological observation and MLI detection showed that compared with the control group， the model group showed obvious inflammatory infiltration， alveolar enlargement and fusion， and increased MLI （P<0.05）. Compared with the model group， EOFAZ effectively alleviated the pathological changes such as alveolar dilatation， pulmonary inflammatory cell infiltration， and lung cell apoptosis caused by PPE， and decreased the MLI （P<0.05）. As revealed by ELISA， the inflammatory level of mice in the model group increased significantly （P<0.01）， while the TNF-α， IL-1β， and IL-6 levels in the plasma were decreased after quantitative administration of EOFAZ （P<0.01）. Compared with the control group， the model group exhibited significantly enhanced oxidative stress （P<0.01）. After treatment with EOFAZ by quantitative administration， the activities of SOD and CAT in the lung tissue were increased （P<0.01） and the content of MDA was decreased （P<0.01）. Western blot results demonstrated that the apoptosis-related protein expression in the model group was increased significantly as compared with that in the control group （P<0.01）， whereas the expression levels of antioxidant stress proteins Nrf2 and NQO1 declined （P<0.05）. The relative protein expression of apoptosis-related proteins Bax/Bcl-2 in the EOFAZ groups was lower than that in the model group （P<0.01）， while the expression of antioxidant stress proteins Nrf2 and NQO1 was higher （P<0.05）. ConclusionQuantitative pulmonary administration of EOFAZ effectively alleviates the inflammation and oxidative stress， reduces lung cell apoptosis， and hinders the occurrence and development of emphysema. Its antioxidant mechanism is closely related to the up-regulation of Nrf2 and its downstream NQO1.