Curcumin protects BEAS-2B cells from PM2.5-induced oxidative stress and inflammation by activating NRF2/antioxidant response element pathways

Abstract

Fine particulate matter (PM2.5) with an average aerodynamic diameter of <2.5 µm can cause severe lung injury. Oxidative stress and inflammation are considered the main outcomes of PM2.5 exposure. Curcumin is a well-known antioxidant; however, its effect on PM2.5-induced oxidative injury in airway epithelial cells remains unclear. In the present study, it was demonstrated that pre-treatment with curcumin significantly reduced the PM2.5-induced apoptosis of BEAS-2B human bronchial epithelial cells by decreasing the level of intercellular reactive oxygen species. Western blot analysis revealed that curcumin increased the expression of nuclear factor erythroid 2-related factor 2 (NRF2) and regulated the transcription of downstream genes, particularly those encoding antioxidant enzymes. Moreover, curcumin reduced the PM2.5-induced expression and production of inflammatory factors, and induced the expression of the anti-inflammatory factors, interleukin (IL)-5 and IL-13. Taken together, the present study demonstrates that curcumin protects BEAS-2B cells against PM2.5-induced oxidative damage and inflammation, and prevents cell apoptosis by increasing the activation of NRF2-related pathways. It is thus suggested that curcumin may be a potential compound for use in the prevention of PM2.5-induced tissue injury.