3-hydroxy-2-methylquinoline-4-carboxylic acid

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

- negative: Ames test with Salmonella typhimurium TA 1535, TA 1537, TA 98 and TA 100 (met. Act.: with and without) (OECD TG 471 (adopted 1983); GLP); REL2; cytotoxicity: no

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted 1983

GLP compliance:

no

Remarks:

Study conducted prior to implementation of GLP

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch No.of test material: P. 231/89
- Test substance No.: 89/881
- Degree of purity: >92%

Target gene:

histidine locus

Species / strain / cell type:

S. typhimurium TA 1535

Species / strain / cell type:

S. typhimurium TA 1537

Species / strain / cell type:

S. typhimurium TA 98

Species / strain / cell type:

S. typhimurium TA 100

Metabolic activation:

with and without

Metabolic activation system:

S9 Mix

Test concentrations with justification for top dose:

1st Experiment (standard plate test; TA 1535, TA1537): 0, 20, 100, 500, 2500 and 5000 µg/plate
2nd Experiment (standard plate test; TA100, TA98): 0, 20, 100, 500, 2500 and 5000 µg/plate
3rd Experiment (pre-incubation test; TA1535, TA 100, TA 1537, TA 98): 0, 20, 100, 500, 2500 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: complete solubility of the test substance

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

other: With S9 Mix: 2-aminoanthracene in DMSO (for strains TA 100, TA98, TA 1537, TA 1535; without S9-Mix: N-methyl-N'-nitro-N-nitroso-guanidine in DMSO (for strains TA 100 and TA 1535), 4-nitro-o-phenylendiamine in DMSO (for strain TA98)

Details on test system and experimental conditions:

METHOD OF APPLICATION:

Plate incorporation tests (experiments 1 and 2);
Preincubation test (experiment 3)

DURATION
- Preincubation period: bacterial suspension with S9 Mix incubated for 20 min at 37°C
- Exposure duration: 48 hours in the dark

NUMBER OF REPLICATIONS: 3 test plates per dose or per control

DETERMINATION OF CYTOTOXICITY
- reduced his- background growth

Evaluation criteria:

substance characterized as positive in the Ames test was based on the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative 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:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Number of revertants per plate (mean of 3 plates; Standard Plate Test)
	[Strain TA 1535]			[Strain TA 100]			[Strain TA 1537]			[Strain TA 98]
Conc.	— MA	+ MA	Cytotoxic	— MA	+ MA	Cytotoxic	— MA	+ MA	Cytotoxic	— MA	+ MA	Cytotoxic
[µg]			(yes/no)			(yes/no)			(yes/no)			(yes/no)
0*	12	14	no	115	114	no	9	12	no	28	38	no
20	21	18	no	101	102	no	10	13	no	23	39	no
100	15	15	no	108	101	no	5	14	no	29	40	no
500	22	12	no	113	99	no	7	16	no	27	42	no
2500	15	14	no	81	102	no	5	12	no	26	40	no
5000	13	12	no	112	112	no	8	13	no	16	38	no
Positive control	1883	231		323	1940		633	325		1280	1333
*solvent control with DMSO

Number of revertants per plate (mean of 3 plates; Pre-incubation Test)
	[Strain TA 1535]			[Strain TA 100]			[Strain TA 1537]			[Strain TA 98]
Conc.	— MA	+ MA	Cytotoxic	— MA	+ MA	Cytotoxic	— MA	+ MA	Cytotoxic	— MA	+ MA	Cytotoxic
[µg]			(yes/no)			(yes/no)			(yes/no)			(yes/no)
0*	17	18	no	118	110	no	10	11	no	25	37	no
20	19	18	no	124	110	no	8	12	no	28	35	no
100	20	21	no	120	116	no	10	13	no	28	36	no
500	17	21	no	125	108	no	9	14	no	23	39	no
2500	14	19	no	121	119	no	14	12	no	27	32	no
5000	15	20	no	116	108	no	11	13	no	26	26	no
Positive control	1297	230		1783	1307		707	111		820	918
*solvent control with DMSO

Conclusions:

The test item was evaluated in the bacterial reverse mutation assay (Ames test) using Salmonella typhimurium strains TA 1535, TA 1537, TA 98 and TA 100 in the presence and absence of rat liver S9 mix. Under the conditions of the study, the test substance was negative for mutagenic potential.

Executive summary:

In a reverse gene mutation assay in bacteria according to OECD guideline 471 (adopted 1983), Salmonella typhimurium strains TA 1535, TA 1537, TA 98 and TA 100 were exposed to the test substance in DMSO in concentrations of 0 (control), 20, 100, 500, 2500 and 5000µg/plate in the presence and absence of mammalian metabolic activation (rat liver S9 mix) in a plate incorporation test and in concentrations of 0 (control), 20, 100, 500, 2500 and 5000µg/plate in the presence and absence of mammalian metabolic activation (rat liver S9 mix) in a pre-incubation test.

Each concentration and the controls were tested in triplicates.

The plates incubated with the test item showed normal background growth up to 5000µg/plate with and without S9 mix in all strains used.

No toxic effects, evident as a reduction in his^- background growth, occurred in the test groups with and without metabolic activation.

No substantial increase in revertant colony numbers of any of the four tester strains was observed following treatment with the test substance at any concentration level, neither in the presence nor in the absence of metabolic activation (S9 mix). l increase in revertant colony numbers of any of the four tester strains was observed following treatment with the test substance at any concentration level, neither in the presence nor in the absence of metabolic activation (S9 mix).

Appropriate reference mutagens were used as positive controls. They showed a distinct increase in induced revertant colonies.

The adopted OECD TG 471 (1997) requires at least 5 test strains and the use of E. coli WP2 strains or Salmonella typhimurium TA 102 to detect certain oxidizing mutagens, cross-linking agents and hydrazines. However, the test substance is not a highly reactive agent and is therefore not expected to be a cross-linking agent, has no oxidizing properties and is no hydrazine. Thus, a test according to EU Method B.13/14 (Version Commission Directive 92/69/EEC without E. coli WP2 strains or Salmonella typhimurium TA 102 is considered as sufficient to evaluate the mutagenic activity of the test substance in this bacterial test system.

Under the conditions of the study, the test substance was negative for mutagenic potential.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on reliable, relevant and adequate data on the test substance is considered to be not mutagenic (negative).

According to Regulation EC No. 1272/2008, no classification and labelling for mutagenicity is required.