Effect of puerarin on the release of interleukin-8 in co-culture of human bronchial epithelial cells and neutrophils

Objective To investigate the effect of puerarin on interleukin (IL)-8 mRNA expression and the protein release in the co-culture of human bronchial epithelial (BEAS-2B) cells and human neutrophils. Methods BEAS-2B cells and neutrophills were cultured separately and co-cultured with puerarin (50, 100, and 200 μg/mL) for a predetermined time. Cytokines in culture supernatant were evaluated by protein array and IL-8 quantified by enzyme-linked immunosorbent assay (ELISA). IL-8 mRNA expression was evaluated by real-time quantitative polymerase chain reaction (real-time qPCR). Results The co-culture of BEAS-2B cells and neutrophils exhibited synergistic effects on IL-8 mRNA expression in BEAS-2B cells, but not in neutrophils after 12 h incubation ( P <0.01), as compared with that in BEAS-2B cells or neutrophils alone. IL-8 protein release in the culture supernatant was obviously elevated when BEAS-2B cells were co-cultured with human neutrophils as compared with that in the supernatant of BEAS-2B cells or neutrophils alone after incubated for 2, 6, 12, and 18 h ( P <0.01). Treatment with puerarin could significantly down-regulate the expression of IL-8 mRNA in BEAS-2B cells and IL-8 release in the supernatant of the co-culture of BEAS-2B cells and neutrophils ( P <0.01). Conclusion Puerarin could exhibit anti-inflammatory activity by suppressing IL-8 production from the co-culture of human bronchial epithelial cells and neutrophils.