Table 3.

Genotoxicity evaluated by CBMN Cyt assay in PBL and Raw264.7 cells exposed to increasing mass concentrations of Au NPs

	MN		NPB		NBUD
	PBL	Raw264.7	PBL	Raw264.7	PBL	Raw264.7
C−	3.25±0.75	2.3±0.5	0.5±0.5	1.2±0.4	0±0	0.5±0.5
C+	43.3±7.2***	32.4±5.6***	14.4±0.8***	13.4±1.0**	2.8±0.5***	7.0±1.5***
Au NP 5 nm
0.1 μg/mL	5.0±1.4	5.1±1.1	2.2±0.5**	1.8±0.5	1.5±0.5**	1.3±0.6
1 μg/mL	7.0±2.0	4.5±1.2	2.2±0.2**	1.4±0.8	4.3±0.3***	1.0±0.8
10 μg/mL	8.5±0.35*	5.4±1.4	2.0±0.4**	1.4±0.8	2.5±0.4***	2.0±0.8
100 μg/mL	12.5±0.35**	7.4±1.1**	3.2±0.6**	1.8±0.4	6.7±0.9***	1.3±0.4
Au NP 15 nm
0.1 μg/mL	9.2±1.2*	17.5±1.5**	2.0±0.5**	4.2±1.2*	0.5±0.5	5.5±0.5***
1 μg/mL	12.5±0.5**	25.0±2.0***	2.8±0.7**	4.8±0.5*	2.5±0.5***	7.0±1.0***
10 μg/mL	14.3±1.2**	27.5±2.5***	2.8±1.0**	4.8±0.8*	5.5±0.7***	7.5±1.5***
100 μg/mL	22.4±2.3***	Toxic	3.2±1.5**	Toxic	12±1***	Toxic

Notes: MN, NPB, and NBUD frequencies scored by CBMN Cyt assay after exposure of PBL and Raw264.7 to increasing mass concentrations of Au NPs (0.1–100 μg/mL). In PBL, 5 nm and 15 nm Au NPs induced dose-dependent effect in MN (P=0.0014 and P=0.03, respectively), NPB (P=0.012 and P=0.033; respectively), and NBUD frequency (P=0.05 and P=0.02, respectively). MN frequency of Raw264.7 exposed to 15 nm Au NPs showed a dose-dependent relationship (P=0.05). Statistically significant differences from the control were determined by the Student’s t-test (*P<0.05; **P<0.01; ***P<0.001). Data represent the mean ± SEM (PBL: n=4; Raw264.7: n=6).

Abbreviations: Au NP, gold nanoparticle; C+, positive control (0.1 μg/mL mitomycin C); C−, negative (untreated) control; CBMN Cyt, cytokinesis-block micronucleus cytome; MN, micronuclei; NBUD, nuclear buds; NPB, nucleoplasmic bridges; PBL, peripheral blood lymphocytes; SEM, standard error of the mean.