L-alanine

Genetic toxicity: in vitro

Administrative data

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:

other: Study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Mutagenesis by normal metabolites in Escherichia coli: phenylalanine mutagenesis is dependent on error-prone DNA repair

Author:

Sargentini, N. J.; Smith, K.C.

Year:

1986

Bibliographic source:

Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, Volume 161, Issue 2, July 1986, Pages 113-118

Materials and methods

Principles of method if other than guideline:

Scientific investigation. Principle similiar to Ames-test. In search of a model for the production of 'spontaneous' mutations induced by DNA damage produced during normal metabolism, 19 amino acids were tested for mutagenicity.

GLP compliance:

no

Remarks:

study performed prior to implementation of GLP

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

L-alanine

EC Number:

200-273-8

EC Name:

L-alanine

Cas Number:

56-41-7

Molecular formula:

C3H7NO2

IUPAC Name:

L-alanine

Method

Target gene:

uvrB, uvrB umuC

Species / strain

Species / strain 1

Species / strain / cell type:

E. coli, other: SR250 (uvrB5)

Details on mammalian cell type (if applicable):

derived from E coli K-12 strain, SR248 (wild-type)

Additional strain / cell type characteristics:

other: DNA repair-deficient strain

Species / strain 2

Species / strain / cell type:

E. coli, other: SR1034 ( uvrB5 umuC 122::Tn5)

Details on mammalian cell type (if applicable):

derived from E coli K-12 strain, SR248 (wild-type)

Additional strain / cell type characteristics:

other: DNA repair-deficient strain

Metabolic activation:

without

Test concentrations with justification for top dose:

2mM L-alanine

Controls

Untreated negative controls:

yes

Remarks:

(wild type of E. coli)

Negative solvent / vehicle controls:

no

True negative controls:

yes

Remarks:

(wild type of E. coli)

Positive controls:

no

Details on test system and experimental conditions:

Plate assay and tube assay

Evaluation criteria:

Median values for mutants and CFU (colony forming units) were used to determine the median mutant frequencies for each assay.

Statistics:

Significant effects on mutagenesls were defined by either of two criteria.
That is, the mean mutant frequency + 1 SD (range) for the amino-acid-supplemented plates did not overlap the range for the control plates, and the mean relative (test/control) range for the uvrB strain did not overlap the mean relative range for the uvrB umuC strain.

Results and discussion

Test results

Species / strain:

E. coli, other: Both SR250 and SR1034

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

not applicable

Untreated negative controls validity:

valid

Positive controls validity:

not applicable

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

L-Alanine does not exhibit mutagenic activity under the conditions of this bacterial reverse mutation assay.