3-methylsulphanilic acid

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames mutagenicity test was conducted for chemical 4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid) to evaluate its genetoxic effects when exposed to Salmonella typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538 with dose concentration of 100-10000 µg/plate in plate incorporation assay. Based on the preliminary study conducted, the test compound was used at a five dose level from 100- 10000 µg/plate. Concurrent solvent and positive control chemicals were used in the study. For a test article to be considered positive, it had to induce at least a doubling (TA98, TA100, and TA1535) in the mean number of revertants per plate of at least one tester strain. This increase in the mean revertants per plate had to be accompanied by a dose response to increasing concentrations of the test chemical. If the study showed a dose response with a less than 3-fold increase on TA1537 or TA1538, the response had to be confirmed in a repeat experiment. However, 4-amino-m-toluenesulfonic acid did not show a dose depnedent increase in the number of revertants. On the basis of results noted, 4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid) failed to induce mutation in the Salmonella typhimurium TA98, TA100, TA1535, TA1537, and TA1538 both in the presence and absence of S9 activation system and hence is not likely to be a gene mutant in vitro.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed publication

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

The Ames salmonella typhirium mutagenicity test was conducted for chemical 4-amino-m-toluenesulfonic acid to determine its mutagenic nature

GLP compliance:

no

Type of assay:

bacterial gene mutation assay

Specific details on test material used for the study:

- Name of test material: 4-amino-m-toluenesulfonic acid
- IUPAC name: 3-methylsulphanilic acid
- Molecular formula: C7H9NO3S
- Molecular weight: 187.218 g/mol
- Substance type:Organic
- Physical state: Solid
- Purity: No data available
- Impurities (identity and concentrations):No data available

Target gene:

Histidine

Species / strain / cell type:

S. typhimurium, other: TA98, TA100, TA1535, TA1537, and TA1538

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Test concentrations with justification for top dose:

10-10000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Yes, no detailed data available
- Justification for choice of solvent/vehicle: No data available

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

not specified

Details on test system and experimental conditions:

Details on test system and conditions
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: No data available
- Exposure duration: 48 h
- Expression time (cells in growth medium): 48 h
- Selection time (if incubation with a selection agent): No data available
- Fixation time (start of exposure up to fixation or harvest of cells): No data available

SELECTION AGENT (mutation assays): No data available
SPINDLE INHIBITOR (cytogenetic assays): No data available

STAIN (for cytogenetic assays): No data available

NUMBER OF REPLICATIONS: Triplicate

NUMBER OF CELLS EVALUATED: No data available

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data available

OTHER EXAMINATIONS:
- Determination of polyploidy: No data available
- Determination of endoreplication: No data available
- Other: No data available

OTHER: No data available

Rationale for test conditions:

No data

Evaluation criteria:

The criteria used to evaluate a test were as follows: for a test article to be considered positive, it had to induce at least a doubling (TA98, TA100, and TA1535) in the mean number of revertants per plate of at least one tester strain. This increase in the mean revertants per plate had to be accompanied by a dose response to increasing concentrations of the test chemical. If the study showed a dose response with a less than 3-fold increase on TA1537 or TA1538, the response had to be confirmed in a repeat experiment.

Statistics:

No data available

Species / strain:

S. typhimurium, other: TA98, TA100, TA1535, TA1537, and TA1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: No data
- Effects of osmolality: No data
- Evaporation from medium: No data
- Water solubility: No data
- Precipitation: No data
- Definition of acceptable cells for analysis: No data
- Other confounding effects: No data

RANGE-FINDING/SCREENING STUDIES: The doses that were tested in the mutagenicity assay were selected based on the levels of cytotoxicity observed in a preliminary dose range-finding study using strain TA100. Ten dose levels of the chemical, one plate per dose, were tested in both the presence and the absence of induced hamster S9. If no toxicity was observed, a total maximum dose of 10 mg of test chemical per plate was used.

CYTOKINESIS BLOCK (if used)
- Distribution of mono-, bi- and multi-nucleated cells: No data

NUMBER OF CELLS WITH MICRONUCLEI
- Number of cells for each treated and control culture: No data
- Indication whether binucleate or mononucleate where appropriate: No data

HISTORICAL CONTROL DATA (with ranges, means and standard deviation and confidence interval (e.g. 95%)
- Positive historical control data: No data
- Negative (solvent/vehicle) historical control data: No data

ADDITIONAL INFORMATION ON CYTOTOXICITY:
- Measurement of cytotoxicity used: No data
- Other observations when applicable: No data

Conclusions:

4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid) failed to induce mutation in the Salmonella typhimurium TA98, TA100, TA1535, TA1537, and TA1538 both in the presence and absence of S9 activation system and hence is not likely to be a gene mutant in vitro.

Executive summary:

Ames mutagenicity test was conducted for chemical 4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid) to evaluate its genetoxic effects when exposed to Salmonella typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538 with dose concentration of 100-10000 µg/plate in plate incorporation assay. Based on the preliminary study conducted, the test compound was used at a five dose level from 100- 10000 µg/plate. Concurrent solvent and positive control chemicals were used in the study. For a test article to be considered positive, it had to induce at least a doubling (TA98, TA100, and TA1535) in the mean number of revertants per plate of at least one tester strain. This increase in the mean revertants per plate had to be accompanied by a dose response to increasing concentrations of the test chemical. If the study showed a dose response with a less than 3-fold increase on TA1537 or TA1538, the response had to be confirmed in a repeat experiment. However, 4-amino-m-toluenesulfonic acid did not show a dose depnedent increase in the number of revertants. On the basis of results noted, 4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid) failed to induce mutation in the Salmonella typhimurium TA98, TA100, TA1535, TA1537, and TA1538 both in the presence and absence of S9 activation system and hence is not likely to be a gene mutant in vitro.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Gene toxicity in vitro:

Variuos peer reviewed publications were reviewed to determine the mutagenic nature of 4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid). The summary is as mentioned below:

Ames mutagenicity test was conducted as mentioned in the publication by the author Seifried et al (Chem. Res. Toxicol, 2006) for chemical 4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid) to evaluate its genetoxic effects when exposed to Salmonella typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538 with dose concentration of 100-10000 µg/plate in plate incorporation assay. Based on the preliminary study conducted, the test compound was used at a five dose level from 100- 10000 µg/plate. Concurrent solvent and positive control chemicals were used in the study. For a test article to be considered positive, it had to induce at least a doubling (TA98, TA100, and TA1535) in the mean number of revertants per plate of at least one tester strain. This increase in the mean revertants per plate had to be accompanied by a dose response to increasing concentrations of the test chemical. If the study showed a dose response with a less than 3-fold increase on TA1537 or TA1538, the response had to be confirmed in a repeat experiment. However, 4-amino-m-toluenesulfonic acid did not show a dose depnedent increase in the number of revertants. On the basis of results noted, 4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid) failed to induce mutation in the Salmonella typhimurium TA98, TA100, TA1535, TA1537, and TA1538 both in the presence and absence of S9 activation system and hence is not likely to be a gene mutant in vitro.

In the same study by Seifried et al, gene mutation study was also conducted according to L5178Y TK+/- Mouse Lymphoma Mutagenicity Assay to determine the mutagenic nature of 4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid). The Cells at a concentration of 6 X 10⁵/mL (6 X10⁶cells total) were exposed for 4 h to a range of concentrations from 3500 - 7500 µg/mL of the test chemical. The cells were then washed, resuspended in growth medium, and incubated at 37°C for 48 h. The rate of cell growth was determined for each of the treated cultures and compared to the rate of growth of the solvent controls.Results were interpreted using a doubling of the mutant frequency over the concurrent solvent-treated control value as an indication of a positive effect, together with evidence of a dose-related increase. 4-amino-m-toluenesulfonic acid failed to induce a doubling of the mutant frequency both in L5178Y TK+/- 3.7.C mouse lymphoma cells in the absence of S9 activation system and induced mutation in the presence of S9 metabolic activation system.

Though 4-amino-m-toluenesulfonic acid has been observed to show mutagenic nature in the cell line in the presence of metabolic activation system but

Key study information suggests the chemical to be not mutagenic in vitro in the presence and absence of S9 metabolic activation system. Also similar results are observed in the supporting study of mouse lymphoma mutagenicity assay performed using L5178Y TK+/- cell line in the absence of metabolic activation system. Based on the information observed for the test chemical, it is summarized that 4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid) is not likely to exhibit genetic toxicity. Thus, the chemical is not classified as a genetic toxicant.

Justification for classification or non-classification

Based on the information observed for the test chemical, it is summarized that 4-amino-m-toluenesulfonic acid (IUPAC name: 3-methylsulphanilic acid)

is not likely to exhibit genetic toxicity. Thus, the chemical is not classified as a genetic toxicant.