Dilactide

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Absence of mutagenic activity of acidity regulators in the Ames Salmonella/microsome test

Author:

Al-Ani, F.Y.; Al-Lami, S.K

Year:

1988

Bibliographic source:

Mutation Research 206: 467-470

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

Not all required strains were tested (see below)

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Lactic acid

EC Number:

200-018-0

EC Name:

Lactic acid

Cas Number:

50-21-5

Molecular formula:

C3H6O3

IUPAC Name:

2-hydroxypropanoic acid

Method

Target gene:

Histidine locus

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA97, TA 98, TA100, TA104

Metabolic activation:

with and without

Metabolic activation system:

rat liver homogenate S9

Test concentrations with justification for top dose:

0.5, 1.0 and 2.0 microliter lactic acid/plate

Vehicle / solvent:

Medium/water

Controls

Untreated negative controls:

yes

Remarks:

medium

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Details on test system and experimental conditions:

Strains and culture medium:
Salmonella typhimurium strains TA97, TA98, TA100 and TA104 were provided by Professor B. N. Ames. Their genotypes were confirmed according to Maron and Ames (1983). The soltions and media were prepared according to Maron and Ames (1983).
Preparation of rat liver enzymes:
The method of Sezzano et al. (1982) was adopted for induction of cytochrome P-450 in male CD-COBS rats (200-250 g). 0, 40, 60, 80, 100 mg/kg bw of phenobarbital (PB) were administered intraperitoneally in 3 doses (1 mL/day). Liver homogenate S9 fraction was prepared as in Ames et aI. (1975). The activity of the prepared S9 was evaluated using 2 tester strains (TA100 and TA98) and the positive control mutagen 2-aminoanthracene (2-AA).
Mutagenesis assay:
Several concentrations of the acidity regulators anhydrous citric acid, phosphoric acid, malic acid and lactic acid, dissolved in distilled water, were tested for mutagenicity in the standard plate incorporation assay (Maron and Ames, 1983). Distilled water (solvent) was used as the negative control. All tests were done in triplicate, both with and without S9.
Protein assay:
The protein concentration of liver homogenate S9 fraction was determined according to Kalcker (1947).

Evaluation criteria:

Number of revertants as compared to number of convertants in the control

Statistics:

Not mentioned, most likely t-test, or possibly ANOVA.

Results and discussion

Test results

Species / strain:

S. typhimurium, other: Strains TA97, TA98, TA100, TA104

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not applicable

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Under the experimental conditions reported, lactic acid did not cause gene mutations with and without metabolic activation. Therefore, the test item is considered to be non-mutagenic in this bacterial reverse gene mutation assay.

Executive summary:

The activities of various concentrations of 4 acidity regulators (anhydrous citric acid, phosphoric acid, malic acid and lactic acid) used in food industries in Iraq was assayed using the Salmonella/microsome mutagenicity assay. None of the samples was mutagenic in the absence or in the presence of S9 to any of the tester strains of Salmonella typhimurium.