Fig. 3

Roles of oxidative stress and PARP activation in SiNPs-induced cytotoxicity in BEAS-2B cells. a Cell viability determined using a Cell Counting Kit-8 (CCK-8) after exposure to SiNPs at different doses (0, 12.5, 25, 50, 100 and 200 μg/mL) for 24  and 48 h. b-e The levels of mRNA expression for IL-1β (b), IL-6 (c), CXCL-1 (d) and CXCL-8 (e) in cells under control or after exposure to SiNPs (100 μg/mL) in the absence or presence of PJ34 (10 μM). f Representative confocal microscopic images showing DCFH-DA fluorescence intensity in cells under control condition (CTRL), or after treatment with SiNPs (100 μg/mL) for 12 h in the absence or presence of NAC (5 mM), or NAC (5 mM) alone. Scale bar = 50 μm. g Mean DCFH-DA fluorescence intensity under indicated conditions, as shown in f, from 200 cells analyzed for each condition. h Cell viability under control condition and after exposure to SiNPs (100 μg/mL) for 24 h, NAC (5 mM), PJ34 (10 μM) or in combinations. *P < 0.05, **P < 0.01, ***P < 0.001 compared to the control group. ^#P < 0.05, ^##P < 0.01, ^###P < 0.001 compared to SiNPs-treated group