Interleukin-6 and Interleukin-8 Induced by Benzo[a]pyrene、Phenanthrene、Chrysene in Human Bronchial Epithelial BEAS-2B Cell

This study aimed at evaluating the induction of interleukin-6（IL-6）and interleukin-8（IL-8）while the human bronchial epithelial cells, BEAS-2B cell, exposed to authentic benzo[a]pyrene, phenanthrene, and chrysene with concentration at low（4.22~5.54 nM）, medium（98.5~138.5 nM）, and high（492.5~692.5 nM）levels. The exposure lasted for 8, 12, 16, 24, and 48 hours, before the ELISA test were applied for detecting IL-6 and IL-8. The results demonstrated that the induction of IL-6 and IL-8 varied with species of PAH, concentration and exposure time. The change rate of cytokine level per hour exposure（pg/mL-nM/hr）varied with chemical species as the levels of IL-6 and IL-8 were normalized to exposure concentration. The change rate for benzo[a]pyrene was upmost. The does-effect relationship was interpreted by using linear-quadratic model assuming that the level of IL-6 or IL-8 is related to two phases of action. For benzo[a]pyrene, the level of IL-6 and IL-8 were negatively proportional to dose at the lower dose exposure and the level of IL-6 and IL-8 were positively proportional to the square of dose at the higher dose exposure. For exposure to phenanthrene or chrysene, the levels of IL-6 and IL-8 positively increase with the increment of dose at lower dose exposure and then slightly decrease with the square of dose at higher dose exposure. The induction of proinflammatory cytokines in epithelial cell likely occurs due to exposure to polynuclear aromatic hydrocarbons, and the effects mainly depend on chemical species as the other exposure modifiers such as exposure concentration and exposure time are identical.