Effects of Naringenin on mucous hypersecretion in the airway inflammation

【Objection】To investigate the effects of Naringenin on airway mucous hypersecretion under inflammation and the relative molecular mechanism. 【Methods】The cell model of mucous hypersecretion was made by human lung A549 cell stimulated by human neutrophil elastae (HNE), and treated with Naringenin and ROS scavenger DMTU, respectively. The relative content of reactive oxygen species (ROS) were assayed by special kit. The expression of mucin (MUC)5AC, EGFR, P-EGFR were detected. The cell activity after Naringenin treatment was assessed by methylthiazolyl tetrazolium method. The cells were divided into 5 groups: a negative control group, an HNE treatment group, a Naringenin pre-treatment group, a DMTU pre-treatment group and a Naringenin + DMTU group. The changes of MUC5ACmRNA and EGFRmRNA were examined by the use of reverse transcriptase-polymerase chain reaction (RT-PCR). The protein expression changes of EGFR and P-EGFR were measured by Western blot. The protein expression changes of MUC5AC were detected by enzyme-linked immunosorbent assay, while the protein morphological changes of MUC5AC were observed by immunofluorescence and confocal laser technology. The data were analyzed with SPSS 13.0 software. Differences between groups assessed for significance by t-test. 【Results】A dose-dependent increasing of ROS production in cells exposed to HNE was detected, after the cells were pre-treated with Naringenin, the content of ROS was decreased significantly as compared with the 50nmol/L HNE group (P 0.01). The expression levels of MUC5ACmRNA and its protein in the HNE group were 0.92 ± 0.08 and (152 ± 6) μg/mg, and those of EGFR were 0.91 ± 0.05 and (0.86 ± 0.03) μg/mg, both of them increased significantly as compared to those in the control group [0.70 ± 0.02, (112 ± 4) μg/mg and 0.73 ± 0.10, 0.39 ± 0.03] (P 0.05). The protein expression changes of EGFR and P-EGFR were increased significantly as compared with the control group (P 0.01). After the cells were pre-treated with Naringenin, the above measurements were decreased significantly as compared with the HNE group. The decrease was more significant in the Naringenin+DMTU group (P 0.01).【Conclusions】Naringenin inhibited the production of ROS, decreased the level of EGFR by modulating ROS and blocked the phosphorylation of EGFR, and attenuated airway mucous hypersecretion under inflammation.