2-pyridylamine

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Weight of evidence. Two studies available, method according to OECD 417 (non-GLP). Based on available information, the test item is non-mutagenic.

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Standard NTP Protocol.

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

, only 4 strains are tested, 2-aminoanthracene is the sole indicator of the efficacy of the S-9 mix.

Principles of method if other than guideline:

The testing in both strains is the result of an evolution of the protocol described by Haworth et al. (1983). (See attached background material).

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

- Name of test material: 2-Aminopyridine
- Analytical purity: 99 %
- Other: Supplied by Aldrich.

Target gene:

Genes involved in histidine synthesis.

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

Liver S-9 from Aroclor-induced male Sprague-Dawley rats and Syrian hamsters

Test concentrations with justification for top dose:

33.0; 100.0; 333.0; 1000.0; 3333.0; 10000.0 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water

Negative solvent / vehicle controls:

yes

Remarks:

water

Positive controls:

yes

Remarks:

Without metabolic activation

Positive control substance:

sodium azide

Remarks:

TA1535 and TA100

Negative solvent / vehicle controls:

yes

Remarks:

water

Positive controls:

yes

Remarks:

Without metabolic activation

Positive control substance:

9-aminoacridine

Remarks:

TA1537

Negative solvent / vehicle controls:

yes

Remarks:

water

Positive controls:

yes

Remarks:

Without metabolic activation

Positive control substance:

other: 4-nitro-o-phenylenediamine

Remarks:

TA98

Negative solvent / vehicle controls:

yes

Remarks:

water

Positive controls:

yes

Remarks:

With metabolic activation

Positive control substance:

other: 2-aminoanthracene

Remarks:

For all strains with S9

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation, as described by Haworth et al, 1983.

DURATION
- Exposure duration: 20 minutes with the test substance, Salmonella culture(grown overnight) and S9- mix or buffer (37ºC, without shaking).
- Expression time (cells in growth medium): 2 days

NUMBER OF REPLICATIONS: Each dose in triplicate. Experiments were repeated at least 1 week following the initial trial.

DETERMINATION OF CYTOTOXICITY
- Method: A preliminary toxicity test was conducted to determinate the appropriate dose range, the toxicity test was performed using TA100 or the system developed by Waleh et al (1982). Toxic concentrations were those at which a decrease in the number of his+ colonies was seen or at which there was a clearing in the density of the background lawn.

Evaluation criteria:

A chemical was judged to be mutagenic, or weakly mutagenic if it produced a reproducible, dose-related increase in his+ revertants over the corresponding solvent controls in replicate trials.

Key result

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Toxicity was seen at 10000 µg/plate to TA1535 and at 3333 to TA1537.

Vehicle controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Table 1. Mutagenic responses of Salmonella tester strains (mean±SEM; three plates) to 2 -Aminopyridine

Dose	TA 100						TA 1535						TA 1537						TA 98
	NA (-)		10 % HLI (-)		10 % RLI (-)		NA (-)		10 % HLI (-)		10% RLI (-)		NA (-)		10 % HLI (-)		10 % RLI (-)		NA (-)		10 % HLI (-)		10 % RLI (-)
µg/plate	Mean	Sem	Mean	Sem	Mean	Sem	Mean	Sem	Mean	Sem	Mean	Sem	Mean	Sem	Mean	Sem	Mean	Sem	Mean	Sem	Mean	Sem	Mean	Sem
0.0	94	2.3	155	9.6	165	5.4	17	2.4	15	1.9	10	2.5	9	1.9	17	2.0	14	2.2	26	3.2	37	4.8	39	2.1
33.0													7	1.5
100.0	108	5.5	130	10.1	143	7.4	12	2.4	13	1.3	14	1.3	6	0.3	18	2.7	10	0.9	21	3.3	35	4.3	36	7.1
333.0	106	3.2	162	4.2	144	2.5	15	1.5	25	1.9	10	0.3	7	2.2	15	1.8	16	1.5	21	1.2	40	2.8	24	3.2
1000.0	104	7.0	152	8.0	128	2.0	14	2.1	14	1.8	11	2.0	11	2.0	17	2.0	11	1.9	18	2.2	35	5.8	32	0.7
3333.0	97	3.0	157	5.2	151	8.1	9	1.3	1.4	2.6	11	3.5	8	0.3	10	1.8	14	0.9	25	5.0	33	2.6	26	2.2
10000.0	84	5.0	140	22.0	147	3.8	t		8	0.9	9	1.2			11	0.9	11	1.8	21	2.4	32	2.8	22	1.8
POS	1406	35.8	1503	99.9	1133	100.6	978	54.8	396	22.5	240	20.9	195	15.0	111	14.3	108	11.7	201	5.8	872	70.1	1136	86.9

The 0.0 is the solvent control (H2O)

POS: Positive control.

t: complete clearing of background lawn.

HLI: Aroclor 1254 -induced Hamster liver

RLI: Aroclor 1254 -induced Rat liver

(-) non mutagenic

Conclusions:

The test item resulted non mutagenic for the Salmonella mutation assay with the tester strains: TA100, TA1535, TA1537 and TA98 with and without metabolic activation.

Executive summary:

A Salmonella mutation assay was conducted according to the standard NTP protocol, equivalent to OECD guideline 471. The strains TA100, TA1535, TA1537 and TA98 of S. typhimurium were exposed to the test item through the preincubation method in presence and absence of metabolic activation (S-9 Aroclor1254 induced, hamster or rat liver). A preliminary toxicity test was conduced with the strain TA100, no toxic effects were seen up to a concentration of 10 000 µg/plate. At the main test concentrations of 0, 33, 100, 333, 1000, 3333 and 10000 µg/plate were tested. There were no significant increases or dose-related increases in revertant colonies in the tester strains with and without metabolic activation. Toxicity was seen at 10000 µg/plate to TA1535 and at 3333 to TA1537. It was concluded that the test item is not mutagenic.

Reference 2

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

, 2 tester strains, 2 test concentrations.

Principles of method if other than guideline:

Mutagenicity assays were performed according to the published procedures of Ames, McCann & Yamakasi (1975) and Maron & Ames (1983), see attached background material.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

- Name of test material: 2-aminopyridine (CAS 504-29-0; X)
- Other: Supplied by Aldrich Chemical Co.

Target gene:

Histidine synthesis genes.

Species / strain / cell type:

other: S. typhimurium TA98 and TA100

Metabolic activation:

with and without

Metabolic activation system:

Aroclor-induced rat-liver S-9

Test concentrations with justification for top dose:

500 and 1000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO and water

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Details on test system and experimental conditions:

METHOD OF APPLICATION: No data.

Mutagenicity assays were performed according to the published procedures of Ames, McCann & Yamakasi (1975) and Maron & Ames 1983.

NUMBER OF REPLICATIONS: At least two individual screening assays.

DETERMINATION OF CYTOTOXICITY
- Method: Preliminary tests to establish the solubility in DMSO and their toxicity to tester strains.

Evaluation criteria:

The criteria for assessing mutagenicity have been discussed by Ehrenberg (1984).

Statistics:

Student's t test and the results were considered biologically significant if the P values were less than 0.001. P values greater than 0.001 were assumed to represent negative findings.

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: strain/cell type: TA98

Remarks:

Migrated from field 'Test system'.

Table 1. The mean number of revertants produced by the metabolite 2 -Aminopyridine

Test compound	S-9	Conc (µg/plate)	No. of revertants in TA98	Conc plate (µg/plate)	No. of revertants in TA 100
2-Aminopyridine	+	500	20± 2	1000	105 ± 3
	-	500	12 ± 1	500	108 ± 6

Table 2. The mean number of revertants produced by 2 -Aminopyridine following nitrosation.

Test compound	S-9	Conc (µg/plate)	No. of revertants in TA98	Conc plate (µg/plate)	No. of revertants in TA 100
2 Aminopyridine	+	500	29 ± 3	1000	117 ± 2
	-	1000	35 ± 7	1000	127 ± 6

Values are mean ± SD for at least two determinations.

Conclusions:

The test item resulted non-mutagenic in the tester strains S. typhimurium TA98 and TA100.

Executive summary:

A mutagenicity study was conducted according to the published procedures of Ames, McCann & Yamakasi (1975) and Maron & Ames (1983) with the test item pre and post nitrosation, which was conducted according to Andrews et al (1980). Strains TA98 and TA100 of Salmonella typhimurium were exposed to concentrations of 500 and 1000 µg/plate test item, with and without metabolic activation (Aroclor-induced rat liver S-9). Controls were run using nitrite in acetic acid with and without metabolic activation. Water and DMSO were used as solvents. Benzo[a]pyrene was used as control for both tester strains. The test item did not induced significant increases in revertant colonies with and without metabolic activation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Genetic toxicity in vitro: Weight of evidence. A Salmonella mutation assay was conducted according to the standard NTP protocol, equivalent to OECD guideline 471. The strains TA100, TA1535, TA1537 and TA98 ofS. typhimuriumwere exposed to the test item through the preincubation method in presence and absence of metabolic activation (S-9 Aroclor1254 induced, hamster or rat liver). A preliminary toxicity test was conduced with the strain TA100, no toxic effects were seen up to a concentration of 10 000 µg/plate. At the main test concentrations of 0, 33, 100, 333, 1000, 3333 and 10000 µg/plate were tested. There were no significant increases or dose-related increases in revertant colonies in the tester strains with and without metabolic activation. Toxicity was seen at10000 µg/plate to TA1535 and at 3333 to TA1537.It was concluded that the test item is not mutagenic. Moreover, a mutagenicity study was conducted according to the published procedures of Ames, McCann & Yamakasi (1975) and Maron & Ames (1983) with the test item pre and post nitrosation, which was conducted according to Andrews et al (1980). Strains TA98 and TA100 of Salmonella typhimurium were exposed to concentrations of 500 and 1000 µg/plate test item, with and without metabolic activation (Aroclor-induced rat liver S-9). Controls were run using nitrite in acetic acid with and without metabolic activation. Water and DMSO were used as solvents. Benzo[a]pyrene was used as control for both tester strains. The test item did not induced significant increases in revertant colonies with and without metabolic activation. Based on the available data, the test item is not mutagenic.

Justification for classification or non-classification

Based on available information, the test item is not classified according to CLP Regulation (EC) No. 1272/2008.