Table 1.

Mutagenicity assay of GEO on Salmonella typhimurium TA98, TA100, TA102, TA1535, and TA1537 in the presence or absence of metabolic activation.

Treatment	Revertant colonies
	TA98	TA100	TA102	TA1535	TA1537
Without S9 metabolic activation
Negative controla	51 ± 5.3	216 ± 5.0	299 ± 7.2	29 ± 2.6	13 ± 2.6
Positive controlb	132 ± 5.6∗∗	606 ± 7.0∗∗	761 ± 7.2∗∗	133 ± 5.1∗∗	53 ± 4.5∗∗
GEO (mg/plate)
0.05	56 ± 5.3##	219 ± 3.5##	294 ± 6.7##	28 ± 1.5##	12 ± 2.5##
0.1	47 ± 2.5##	211 ± 8.5##	310 ± 5.0##	30 ± 1.5##	13 ± 1.5##
0.125	55 ± 4.0##	220 ± 5.5##	280 ± 12.1##	29 ± 3.2##	12 ± 1.2##
0.25	51 ± 7.2##	206 ± 7.6##	290 ± 2.5##	28 ± 2.1##	11 ± 3.1##
0.5	58 ± 4.5##	205 ± 5.1##	301 ± 4.7##	30 ± 1.0##	12 ± 1.7##
With S9 metabolic activation
Negative controla	57 ± 2.5	224 ± 8.7	293 ± 12.2	30 ± 1.0	10 ± 2.1
Positive controlc	165 ± 3.2∗∗	715 ± 4.5∗∗	935 ± 4.7∗∗	106 ± 5.1∗∗	45 ± 4.5∗∗
GEO (mg/plate)
0.05	52 ± 3.0##	209 ± 13.4##	292 ± 4.5##	29 ± 1.5##	7 ± 0.6##
0.1	51 ± 5.5##	226 ± 6.1##	306 ± 5.0##	32 ± 2.1##	9 ± 0.6##
0.125	54 ± 4.6##	229 ± 5.0##	299 ± .4.0##	33 ± 2.1##	11 ± 1.2##
0.25	52 ± 2.3##	213 ± 10.1##	293 ± 5.7##	31 ± 2.1##	9 ± 0.6##
0.5	49 ± 5.3##	218 ± 11.0##	302 ± 3.1##	31 ± 2.5##	11 ± 2.1##

Data are presented as the mean ± SD (n = 3 plates/group). Statistical analysis was performed using one-way ANOVA followed by Tukey's post-hoc multiple comparison test. ∗∗, P < 0.01 denotes significant differences compared to negative control group. ^##, P < 0.01 denotes significant differences compared to positive control group.

^aDimethyl sulfoxide (DMSO).

^b4-nitro-o-phenylenediamine (0.5 μg/plate) for TA98; sodium azide (1 μg/plate) for TA100 and TA1535; mitomycin C (0.5 μg/plate) for TA102; 9-aminoacridine (0.5 μg/plate) for TA1537.

^cBenzo[a]pyrene (1.0 μg/plate) for TA98 and TA102; 2-aminoanthracene (4 μg/plate) for TA100, TA1535, and TA1537.