Investigations of immunotoxicity and allergic potential induced by topical application of triclosan in mice

Figures & data

Figure 1. Chemical structure of triclosan.

Figure 2. Allergic sensitization potential after dermal exposure to triclosan. Analysis of allergic sensitization potential of triclosan using LLNA. Disintegration per minute (DPM) represent [³H]-thymidine incorporation into draining lymph node cells of BALB/c mice following exposure to vehicle or concentration of triclosan (0.75–3.0%). SI value is stimulation index (fold-change over vehicle control). Bars shown are means (±SE) of five mice per group.

Table 1. Body\organ weights of female B₆C₃F₁ mice dermally exposed to triclosan for 28 days.

		Triclosan
Parameter		0%	0.75%	1.5%	3.0%
Body weight	(g)	20.52 ± 0.33	20.04 ± 0.35	20.32 ± 0.64	20.72 ± 0.32
Kidney weight	(mg)	249 ± 7	256 ± 9	237 ± 8	248 ± 8
	% BW	1.22 ± 0.04	1.28 ± 0.03	1.17 ± 0.04	1.20 ± 0.03
Spleen weight	(mg)	65 ± 3	67 ± 2	71 ± 2	76 ± 3*#
	% BW	0.32 ± 0.01	0.33 ± 0.01	0.35 ± 0.01	0.37 ± 0.02#
Thymus weight	(mg)	38 ± 4	44 ± 7	42 ± 3	39 ± 3
	% BW	0.19 ± 0.02	0.22 ± 0.04	0.21 ± 0.02	0.19 ± 0.01
Liver weight	(mg)	896 ± 18	939 ± 48	999 ± 45*	1058 ± 133**#
	% BW	4.37 ± 0.06	4.68 ± 0.16	4.94 ± 0.15*	5.11 ± 0.12**#

BW, body weight.

Values are expressed as mean ± SE for each group.

Significantly different from acetone control at *p < 0.05 or **p < 0.01.

Linear Trend; #p < 0.05.

Table 2. Hematology parameters of female B₆C₃F₁ mice dermally exposed to triclosan for 28 days.

	Triclosan
Parameter	0%	0.75%	1.5%	3.0%
Hemoglobin (g/dl)	14.18 ± 0.73	13.38 ± 0.92	13.18 ± 0.16	13.30 ± 0.20
Erythrocytes (M/μl)	9.16 ± 0.56	8.76 ± 0.64	9.15 ± 0.15	7.20 ± 1.67
Platelets (K/μl)	487 ± 150	692 ± 128	739 ± 162	996 ± 39*#
Hematocrit (%)	47.86 ± 2.99	45.44 ± 3.39	46.40 ± 0.62	45.08 ± 1.02
MCV (fl)	52.22 ± 0.24	51.84 ± 0.24	51.32 ± 0.15	51.22 ± 0.16
MCH (pg)	15.52 ± 0.22	15.28 ± 0.15	14.58 ± 0.15	15.12 ± 0.11
MCHC (g/dl)	29.74 ± 0.46	29.50 ± 0.33	28.42 ± 0.22	29.54 ± 0.26
PDW (%)	14.86 ± 0.10	15.38 ± 0.12	15.50 ± 0.04	15.80 ± 0.09
Leukocytes (K/μl)	5.95 ± 0.83	5.94 ± 0.97	5.44 ± 0.81	4.56 ± 0.78
% Lymphocytes	67.00 ± 2.19	68.77 ± 3.14	68.59 ± 2.08	71.02 ± 1.37
% Neutrophils	25.48 ± 1.90	23.15 ± 2.14	23.61 ± 1.04	24.03 ± 1.64
% Monocytes	5.28 ± 0.76	5.31 ± 0.65	4.89 ± 0.53	3.98 ± 0.50
% Eosinophils	1.85 ± 0.78	2.21 ± 1.12	2.44 ± 0.70	0.82 ± 0.46
% Basophils	0.39 ± 0.16	0.50 ± 0.23	0.21 ± 0.07	0.41 ± 0.26

MCH, mean corpuscular hemoglobin; MCV, mean corpuscular volume; PDW, platelet distribution width; MCHC, mean corpuscular hemoglobin concentration. Values are expressed as the means (±SE) for each group.

Significantly different from acetone control at *p < 0.05.

Linear Trend; #p < 0.05.

Figure 3. Effects of dermal exposure to triclosan on lymph node and spleen cellularity. Effects of dermal exposure to triclosan for 28 days on (A) lymph node and (B) spleen cellularity in female B₆C₃F₁ mice. Values shown are means (±SE) for each group. Levels of statistical significance are denoted *p < 0.05 and **p < 0.01 as compared to acetone vehicle.

Figure 4. Effects of dermal exposure to triclosan for 28 days on leukocyte populations. Effects of dermal exposure to triclosan for 28 days on (A) total cell number and (B) frequency of lymphocyte subpopulations in female B₆C₃F₁ mice. Numbers of B-cells, CD4⁺ and CD8⁺ T-cells, dendritic cells and NK cells were enumerated using flow cytometry. Values shown are means (±SE) for each group. Levels of statistical significance are denoted *p < 0.05 and **p < 0.01 as compared to acetone vehicle.

Figure 5. Effects of dermal exposure to triclosan for 28 days on splenocyte populations. Effects of dermal exposure to triclosan for 28 days on (A) total cell number and (B) frequency of lymphocyte subpopulations in female B₆C₃F₁ mice. Numbers of B-cells, CD4⁺ and CD8⁺ T-cells, dendritic cells and NK cells were enumerated using flow cytometry. Values shown are means (±SE) for each group.

Figure 6. Triclosan does not suppress the spleen IgM response to SRBC. Analysis of antibody producing cells after a 28-day dermal exposure to triclosan on the (A) total and (B) specific activity IgM response to SRBC in the spleen and serum. (C) Bars represent mean fold-change (±SE) of six mice/group. Cyclophosphamide (CP) was included as the positive control. Levels of statistical significance are denoted *p < 0.05 and **p < 0.01 as compared to acetone vehicle.