Short-term exposure at different doses of diesel and biodiesel exhaust particles inhalation induces lung inflammation

Biodiesel is a clean fuel that reduces particles emission andfew studies assess its effects. The objectives were investigate lung inflammation and pulmonary cytokines on 60 Balb/C mice exposed to filtered air (FA) and two doses (600 and 1200 µg/m 3 ) of both diesel (D) and biodiesel (BD) fuels. BALf, lung histology and cytokines (ET-Ar and iNOs) were available after 24 hours of exposure.There were an increase in mean concentration of the pollutants on biodiesel exhaust compared to diesel: NO (BD600- 89 µg/m 3 , BD1200- 92 µg/m 3 , D600- 20 µg/m 3 , and D1200- 91 µg/m 3 ) and NO 2 (BD600- 118 µg/m 3 , BD1200- 144 µg/m 3 , D600- 31 µg/m 3 , and D1200- 97 µg/m 3 ). Results - BALf: an increase on neutrophils in BD600(p<0.005) and BD1200(p<0.01) compared to FA, and on total cells number (p=0.001) and macrophages (p<0.005) in BD1200 compared to FA and D600. Lung histology: an increase on neutrophils in BD600 (p=0.001) compared to FA, BD1200, D600 and D1200, an increase on macrophages in BD600 compared to FA (p<0.05) and BD1200 (p<0.01). Lung cytokines: an increase on ET-Ar in BD600 compared to FA, D600 and BD1200 in both peribronchiolar vessels (p=0.001) and bronchial epithelium (p<0.01, p=0.001, and p<0.05 respectively). The iNOs expression in peribronchiolar vessels showed an increase on FA (p<0.05) and BD600 (p<0.01) compared to BD1200, and the iNOs in bronchial epithelium showed increase in D600 compared to FA (p=0.001), BD600 (p=0.001) and D1200 (p<0.01). A single acute exposure of biodiesel, independently of dose, provokes pulmonary inflammation. The biodiesel exposure, even at lower dose, was capable to cause constriction in both peribronchiolar vessels and bronchial epithelium.