Zinc dilactate

Genetic toxicity: in vitro

Administrative data

Endpoint:

genetic toxicity in vitro

Remarks:

Type of genotoxicity: genome mutation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Not reported

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1984

Materials and methods

Principles of method if other than guideline:

The test material was studied to determine the ability to cause DNA damage and thereby induce a pleiotropic response in the E. coli strain. The pleiotopic response was determined by checking for the induction of λ prophage.

GLP compliance:

not specified

Type of assay:

other: Induction of λ prophage in E. coli WP2s (λ)

Test material

Test material information

Constituent 1

Reference substance name:

Zinc chloride

EC Number:

231-592-0

EC Name:

Zinc chloride

Cas Number:

7646-85-7

IUPAC Name:

zinc dichloride

Details on test material:

- Name of test material (as cited in study report): Zinc chloride

Method

Target gene:

Not reported

Species / strain

Species / strain / cell type:

E. coli WP2

Details on mammalian cell type (if applicable):

- Type and identity of media: Minimal Broth Davis (Difco) containing 0.2 % glucose and 20 µg/mL tryptophan (MST)

Additional strain / cell type characteristics:

not specified

Metabolic activation:

not specified

Metabolic activation system:

Not reported

Test concentrations with justification for top dose:

3.2 mM

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Minimal Broth Davis (Difco) containing 0.2 % glucose and 20 µg/mL tryptophan (MST)

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

Streptomycin

Negative solvent / vehicle controls:

yes

Remarks:

Minimal Broth Davis (Difco) containing 0.2 % glucose and 20 µg/mL tryptophan (MST)

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: N-Methyl-N'-nitro-N-nitrosoguanidine

Controls 2

Untreated negative controls:

yes

Remarks:

Streptomycin

Negative solvent / vehicle controls:

yes

Remarks:

Minimal Broth Davis (Difco) containing 0.2 % glucose and 20 µg/mL tryptophan (MST)

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium


DURATION
- Exposure duration: 20 h


NUMBER OF REPLICATIONS: Duplicate

Evaluation criteria:

Clear (non-turbid) wells can occur because of toxicity of the test agent, inhibition of growth, or induction of λ prophage and cell lysis. Thus clear wells indicate toxicity and growth inhibition.

Statistics:

Not reported

Results and discussion

Test results

Species / strain:

E. coli WP2

Metabolic activation:

without

Genotoxicity:

ambiguous

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Not reported

Any other information on results incl. tables

None

Applicant's summary and conclusion

Conclusions:

Under the test conditions, 3.2 mM of the test material caused two-fold increase in induction of λ prophage over control (reported as +/-).

Executive summary:

A study was conducted to determine the potential of the test material for induction of λ prophage in E coli WP2 (λ).

 

The test material in MST was inoculated with 75 µL of a mid-exponential culture of WP_s(λ) diluted so that each well receives approximately 2 x 10⁷bacteria. The test plate was incubated at 37 °C and scored after 20 h for turbidity. MNNG and 4NQO served as positive controls and streptomycin as negative control.

 

Under the test conditions, 3.2 mM of the test material caused a two-fold increase in induction of λ prophage over control (reported as +/-).