Fig. 3.

Pro-inflammatory cytokines in BALF after intratracheal instillation of NiO NPs, NiCl₂, and OVA. NiO NPs were instilled at 200 cm²/rat and evaluated the expression of pro-inflammatory cytokines at 1, 2, 3, and 4 days after instillation. NiCl₂ was instilled at 378.0 μg/rat, which is equivalent to the nickel dose (171.1 μg Ni/rat) of NiO NPs at 200 cm²/rat, and pro-inflammatory cytokines were measured at 1 day after instillation. a IL-1β. b CINC-3. c Eotaxin. Abbreviations: VEH, vehicle control for NiO NPs and NiCl₂; OVA, ovalbumin-induced allergic airway inflammation; VEH_OVA, vehicle control for OVA group. Mean ± SEM (n = 10 for NiO NPs and n = 4 for NiCl₂ and OVA group). One-way ANOVA test was applied for comparison between NiO NPs and VEH with statistical significance indicated by ^*** p < 0.001. Student’s t-test was applied for comparison of NiCl₂ against VEH and OVA group against VEH_OVA with statistical significance indicated by ^### p < 0.001