Effects of tear gases on toxicity, inflammatory parameters and functions of bronchial epithelial cell cultures in COPD

Although limited recent studies suggest that capsaicin, which is widely used in to putting mass demonstrations under control, has negative effects on the respiratory system, the underlying mechanisms and role of bronchial epithelial cells (BEC) are not adequately known. We aimed to investigate effects of capsaicin on BEC cultures obtained from non-smokers, smokers and COPD patients. BEC cultures were incubated with 0, 50, 125, 250 ve 500μM capsaicin in the absence and presence of formoterol (1µM) and roflumilast (0.1µM) for 24 hours. Trans-epithelial electrical resistance (TEER) and ciliary beat frequency (CBF) were assessed at ¼, ½, 1, 2, 4, 6, and 24 hours, whereas release of lactate dehydrogenase (LDH), granulocyte macrophage - colony stimulating factor (GM-CSF) and interleukin (IL)-8 levels were measured at t24hrs. The highest concentrations of capsaicin (250-500µM) significantly decreased (p<0.05) TEER of BEC cultures of non-smokers (t2, t6, t24hrs), smokers (t24hrs) and COPDs (t2 and t24hrs). This effect was partially prevented by roflumilast. Capsaicin significantly reduced CBF of BEC cultures of all study groups from 15 minutes onwards (p<0.05). Formoterol significantly prevented the decrease in CBF, whereas roflumilast did not show any effect. Capsaicin (500µM) decreased release of IL-8 (p<0.0001) and GM-CSF (p<0.05), while inducing release of LDH in all culture groups (p<0.05). In conclusion, our findings have demonstrated that capsaicin, the active component of tear gas, induces BEC culture permeability and LDH release, while inhibiting ciliary activity and cytokine release, and that these effects can be partially prevented by formoterol and roflumilast.