ABSTRACT

The single dose toxicity test revealed an LD50 of above 2000 mg/kg for both sexes. In the repeat dose study, an increase in water consumption was observed in males of the 1000 mg/kg group and lowering of the urinary pH was observed in males and females of the 1000 mg/kg group. These changes disappeared by 14 days after withdrawal. No effects were observed in terms of clinical signs. The NOEL for repeat dose toxicity for both sexes is considered to be 300 mg/kg/day.

3-Aminobenzenesulfonic acid was not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA. In the presence of an exogenous metabolic activation system, this chemical substance induced structural chromosomal aberrations in CHL/IU cells. Lowering of the pH of the culture medium might have contributed to the response. Polyploid cells were not induced under the experimental conditions.

SUMMARIZED DATA OF THE STUDIES

1. Single Dose Oral Toxicity 1)

Purity	:	98.6%
Test species/strain	:	Rat/Crj:CD (SD)
Test method	:	OECD Test Guideline 401
Dosage	:	500, 1000, 2000 mg/kg
Number of animals	:	Male, 5; female, 5/group
GLP	:	Yes

　Test results:

In clinical observation, both sexes of the 500 and 1000 mg/kg groups showed diarrhea with soft feces on the administration day and the following day, and yellow-discolored urine on the administration day. However, no deaths occurred in both sexes of all treated groups, and no changes were observed in terms of body weights, autopsy or histopathology.

LD50:male, > 2000 mg/kg; female, > 2000mg/kg

2. Repeat Dose Toxicity 1)

Purity	:	98.6%
Test species/strain	:	Rat/Crj:CD (SD)
Test method	:	Guidelines for 28-Day Repeat Dose Toxicity Testing for Chemicals (Japan)
Route	:	Oral (gavage)
Dosage	:	0 (vehicle), 100, 300, 1000 mg/kg/day
Number of animals	:	Male, 7 or 14(0 ,1000 mg/kg); Female, 7 or 14(0 ,1000 mg/kg)
Vehicle	:	0.5% CMC-Na solution
Administration period	:	Male and female, 28 days
Terminal kill	:	Day 29 or 43
GLP	:	Yes

　Test results:

Water consumption increased in males of the 1000 mg/kg group during the late phase of administration. Decreased urinary pH values were noted in both sexes receiving 1000 mg/kg.These changes disappeared by 14 days after withdrawal. No effects were observed in terms of clinical signs, body weighs, food consumption, hematology, blood chemistry, organ weights, and autopsy or histopathology findings.

The NOEL for repeat dose toxicity for both sexes is considered to be 300 mg/kg/day.

3. Genetic Toxicity

3-1 Bacterial test 2)

Purity	:	98.6%
Test species/strains	:	S.typhimurium TA100, TA1535, TA98, TA1537, E. coli WP2 uvrA
Test method	:	Guidelines for Screening Mutagenicity Testing of Chemicals (Japan)
Procedures	:	Plate incorporation method
Solvent	:	DMSO
Positive controls	:	-S9, AF-2 (TA100, WP2, TA98), sodium azide (TA1535) and 9-aminoacridine (TA1537) +S9, 2-aminoanthracene (all strains)
Dosage	:	0, 312.5, 625, 1250,2500, 5000 μg/plate
S-9	:	Rat liver, induced with phenobarbital and 5,6-benzoflavone
Plates/test	:	3
Number of replicates	:	2
GLP	:	Yes

　Test results:

Minimum concentration of test substance at which toxicity was observed:

No toxicity was observed up to a concentration of 5000 μg/plate with or without metabolic activation.

Genetic effects:
S. typhimurium TA100, TA1535, TA 98, TA1537

	+	?	-
with metabolic activation	[ ]	[ ]	[*]
without metabolic activation	[ ]	[ ]	[*]

E. coli WP2 uvrA

with metabolic activation	[ ]	[ ]	[*]
without metabolic activation	[ ]	[ ]	[*]

3-2. Non-bacterial in vitro test (chromosomal aberration test) 2)

Purity	:	98.6%
Type of cell used	:	Chinese hamster CHL/IU cells
Test method	:	Guidelines for Screening Mutagenicity Testing of Chemicals(Japan)
Solvent	:	0.5% Carboxymethyl cellulose sodium
Positive controls	:	-S9, Mitomycin C +S9, Cyclophosphamide
Dosage	:	-S9 (continuous treatment): 0, 0.43, 0.85, 1.70 mg/ml -S9 (short-term treatment): 0, 0.41, 0.83, 1.1, 1.65, 2.2, 4.4 mg/ml +S9 (short-term treatment): 0, 0.41, 0.83, 1.1, 1.65, 2.2, 4.4 mg/ml
S-9	:	Rat liver, induced with phenobarbital and 5,6-benzoflavone
Plates/test	:	2
GLP	:	Yes

　Test results:

At the concentration of 0.41 mg/ml and 0.83 mg/ml short-term treatments with S9 mix resulted in 6.5% and 17% of the cells, respectively demonstrating structural aberrations (including gaps). However, it was suggested that acidic pH may have been related to the induction of chromosomal aberration.

Lowest concentration producing cytogenetic effects in vitro:

without metabolic activation (continuous treatment ): > 1.70 mg/ml

without metabolic activation (short-term treatment): > 4.4 mg/ml

with metabolic activation (short-term treatment): 0.41 mg/ml (clastogenicity)

Genotoxic effects:

	clastogenicity			polyploidy
	+	?	-	+	?	-
without metabolic activation:	[ ]	[ ]	[*]	[ ]	[ ]	[*]
with metabolic activation:	[*]	[ ]	[ ]	[ ]	[ ]	[*]

1)	The tests were performed by the Safety Research Institute for Chemical Compound Co., Ltd., 363-24, Shin-ei, Toyohira-ku, Sapporo, Hokkaido 004, Japan Tel 81-11-885-5031 Fax 81-11-885-5313
2)	The tests were performed by the Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano-shi, Kanagawa 257, Japan. Tel +81-463-82-4751 Fax +81-463-82-9627