Roles of lycopene in inflammatory airway mucus hypersecretion

Objective To investigate the effect of lycopene on airway mucus hypersecretion induced by human neutrophil elastae(HNE). Methods Human bronchial epithelial HBE16 cells were stimulated with 0,25,50,75,100,200 and 400 μmol / L lycopene,and determined for activity by MTT method,based on which the lycopene concentration was optimized. The model of airway mucus hypersecretion was established by stimulation with HNE,and treated with lycopene and AG1478. HBE16 cells were divided into five groups. The cells in control group were cultured in serum-free medium, while those in HNE group were treated with HNE at a final concentration of 50 nmol / L,those in HNE + lycopene group were treated with lycopene at a final concentration of 100 μmol / L for 24 h then stimulated with HNE at a final concentration of 50 nmol / L,those in HNE + AG1478 group were pre-treated with 5 μmol / L AG1478 for 30 min then stimulated with 50 nmol / L HNE at a final concentration of 50 nmol / L,and those in HNE + lycopene + AG1478 group were treated with 100 μmol / L lycopene for 24 h,5 μmol / L AG1478 for 30 min,than stimulated with HNE at a final concentration of 50 nmol / L. Samples were taken from various groups 24 h later,and determined for the transcription levels of mucin(MUC5ac),epidermal growth factor receptor(EGFR)mRNAs by RT-PCR,and for expression of EGFR and phosphorylated EGFR(P-EGFR)by Western blot. The expressions of MUC5ac in various groups were determined by ELISA. Results The lycopene at concentrations of less than 100 μmol / L showed no significant damage to cells,so the lycopene concentration for test was served as 100 μmol / L. As compared with those in control group,the transcription levels of MUC5ac and EGFR mRNAs in HNE group as well as expression levels of EGFR and P-EGFR in HNE,HNE + lycopene and HNE + AG1478 groups increased significantly(each P 0. 01). However,as compared with those in HNE group,the transcription levels of MUC5ac and EGFR mRNAs,as well as expression levels of EGFR and P-GEFR in HNE + lycopene,HNE + AG1478 and HNE + lycopene + AG1478 groups decreased significantly(each P 0. 01). The MUC5ac protein content was significantly higher in HNE group than in control group(P 0. 01),and in HNE + lycopene, HNE + AG1478 and HNE + lycopene + AG1478 groups than in HNE group(each P 0. 01). However,as compared with those in HNE + AG1478 group,the expression levels of MUC5ac and EGFR mRNAs and proteins as well as P-EGFR protein in HNE + lycopene + AG1478 group decreased significantly(each P 0. 01). Conclusion Lycopene inhibited the inflammatory airway mucus hypersecretion by down-regulating eGFR level.