Table 1.

The suppression effects of phlorotannins on sensitizer-induced mouse ear swelling.

Sensitizer	Test Groups	Control	Eckol	6,6′-Bieckol	6,8′-Bieckol
AA	Ear swelling (mm)	0.193 ± 0.026	0.169 ± 0.011	0.112 ** ± 0.049	0.116 ** ± 0.036
	Suppression (%)	—	12.7 ± 5.4	41.9 # ± 25.4	39.8 # ± 18.7
TPA	Ear swelling (mm)	0.194 ± 0.038	0.116 ** ± 0.009	0.174 * ± 0.016	0.098 ** ± 0.032
	Suppression (%)	—	40.0 # ± 4.5	34.2 ± 25.2	49.4 * ± 16.4
OXA	Ear swelling (mm)	0.223 ± 0.024	0.180 ± 0.020	0.183 ± 0.030	0.049 ** ± 0.044
	Suppression (%)	—	19.3 ± 9.1	17.8 ± 13.5	77.8 ** ± 19.7
Sensitizer	Test groups	8,8′-bieckol	PFF-A	PFF-B	EGCG
AA	Ear swelling (mm)	0.153 ± 0.011	0.134 * ± 0.021	0.112 ** ± 0.030	0.168 ± 0.008
	Suppression (%)	21.0 ± 5.5	30.5 ± 10.6	42.2 # ± 15.7	12.9 ± 4.2
TPA	Ear swelling (mm)	0.132 * ± 0.014	0.132 * ± 0.007	0.119 ** ± 0.031	0.167 ± 0.008
	Suppression (%)	31.7 ± 7.4	31.7 ± 3.8	38.4 # ± 16.1	13.8 ± 4.4
OXA	Ear swelling (mm)	0.151 * ± 0.030	0.171 ± 0.019	0.131 ** ± 0.032	0.210 ± 0.001
	Suppression (%)	32.3 # ± 13.6	23.4 ± 8.6	41.0 * ± 14.5	5.7 ± 0.1

Suppression effects at a dose of 75 nmol/mouse were calculated from the results of quadruplicate experiments (n = 4). Controls were stimulated by sensitizer without phlorotannins. Values are shown as means ± standard deviations. In each sensitizer experiment, the presence of an asterisk in “Ear swelling” indicates that the ear swelling was significantly lower than that of control (*, p < 0.05; **, p < 0.01). An asterisk in “Suppression” indicates that the suppression ratio was significantly higher than that of EGCG (*, p < 0.05; **, p < 0.01), and “^#” indicates that it tended to be higher than that of EGCG (0.5 < p < 1.0). Abbreviations: AA, arachidonic acid; TPA, 12-O-tetradecanoylphorbol-13-acetate; OXA, oxazolone; PFF, phlorofucofuroeckol; EGCG, epigallocatechin gallate.