Review Article

Health and Cellular Impacts of Air Pollutants: From Cytoprotection to Cytotoxicity

Table 2

The cytoprotective effect of PM2.5 is related to PAHs with five-aromatics rings. Epithelial 16 HBE cells were pretreated during 4 hours with phenanthrene (124 nM), fluoranthene (268 nM), benzo(b)fluoranthene (333 nM), benzo(k)fluoranthene (333 nM), benzo(a)pyrene (270 nM), dibenzo(a,h)anthracene (35 nM), benzo(g,h,i)perylene (443 nM), and indeno(1,2,3-cd)pyrene (217 nM) prior to induction of apoptosis by A23187 (3 μM) for 20 supplementary hours. Results are mean ± SD ( ). Significance was calculated with Dunnett’s test (* versus vehicule cyclohexane 1%). Percentages of DiOC low and PI high refer to cells showing either a drop of Ψm or a permeabilization of the plasma membrane measured using DiOC and propidium iodide (PI) probes, respectively. Note that a 4 h vehicle pretreatment provides % DiOC low and % PI high of A23-induced apoptosis, respectively. Moreover, a 4 h PM2.5 exposure (10 μg/cm²) provides % DiOC low and % PI high of A23-induced apoptosis, respectively. The relative toxic potency of individual PAH compared to BaP is given as the toxic equivalency factor (TEF).

PAHs TEF StructureA23187-induced apoptosis (% of control)
DiOC lowPI high

Phenanthrene0.001–0.01493894.tab.001

Fluoranthene0.001–0.05493894.tab.002

Benzo(b)fluoranthene0.06–0.14493894.tab.003

Benzo(k)fluoranthene0.03–0.1493894.tab.004

Benzo(a)pyrene1493894.tab.005 *

Dibenzo(a,h)anthracene0.69–5493894.tab.006 *

Benzo(g,h,i)perylene0.01–0.03493894.tab.007 * *

Indeno(1,2,3-cd)pyrene0.017–0.232493894.tab.008 *