Yucca schidigera, ext.

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-11-23 - 2019-02-15 (experimental phase: 2018-11-27 - 2018-12-06)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

OECD Guidelines for the Testing of Chemicals Part 471, adopted 21. Jul. 1997 “Bacterial Reverse Mutation Test“

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Version / remarks:

Commission Regulation (EC) No. 440/2008, EU-Method B.13/14 adopted 30. May 2008 “Mutagenicity –Reverse mutation test using bacteria”

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Kaiser-Friedrich-Straße 7, 55116 Mainz, Germany

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Yucca schidigera, ext.

EC Number:

607-033-5

Cas Number:

223749-05-1

IUPAC Name:

Yucca schidigera, ext.

Test material form:

solid: particulate/powder

Remarks:

fine beige

Details on test material:

Storage: Room Temperature (20 ± 5 °C)
Homogeneity: homogeneous

Specific details on test material used for the study:

The test item was stored in the test facility in a closed vessel at room temperature (20±5°C).

Method

Target gene:

his-

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium, other: TA97a

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 3

Species / strain / cell type:

S. typhimurium TA 100

Species / strain 4

Species / strain / cell type:

S. typhimurium TA 102

Species / strain 5

Species / strain / cell type:

S. typhimurium TA 1535

Metabolic activation:

with and without

Metabolic activation system:

Type and composition of metabolic activation system:
- source of S9
S9 was obtained by Trinova Biochem GmbH, Gießen.
Batch nos. 3970, 3833, 3974
- method of preparation of S9 mix:
Produced from the livers of male Sprague-Dawley rats which were treated with 500 mg Aroclor 1254/kg body weight intraperitoneally.
S9-Mix
Phosphate buffer 22.5 mL
0.1M NADP-solution 1.0 mL
1M G6P-solution 0.125 mL
Salt solution 0.5 mL
Rat liver S9 1.0 mL
- concentration or volume of S9 mix and S9 in the final culture medium
500 µL S9 mix in 2700 µl total volume

Test concentrations with justification for top dose:

5000 / 1500 / 500 / 150 / 50 µg/plate (1st experiment)
5000 / 2500 / 1250 / 625 / 313 / 156 µg/plate (2nd experiment)
Top dose and indicated by the guideline, no toxicity was observed.

Vehicle / solvent:

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

- Justification for choice of solvent/vehicle:
In a non-GLP pre-test, the solubility of the test item was tested in a concentration of 50 g/L in demineralized water, dimethyl sulfoxide (DMSO) and acetone.
The solid test item is sufficiently soluble in demin. water, only.
Based on the non-GLP pre-test, demin. water was chosen as vehicle, because the test item was sufficiently soluble, and this solvent does not have any effects on the viability of the bacteria or the number of spontaneous revertants in the tested concentrations.

Controls

Untreated negative controls:

no

Remarks:

water is one of the solvent controls

Negative solvent / vehicle controls:

yes

Remarks:

water and DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

benzo(a)pyrene

other: 4-Nitro-1,2-phenylene Diamine; 2-Amino-Anthracene (2-AA)

Details on test system and experimental conditions:

NUMBER OF REPLICATIONS:
- Number of cultures per concentration: triplicate
- Number of independent experiments : 2

METHOD OF TREATMENT/ EXPOSURE:
- Test substance added in agar (plate incorporation) or preincubation

TREATMENT AND HARVEST SCHEDULE:
- Preincubation period, if applicable: 20 min
- Exposure duration/duration of treatment: 48h

METHODS FOR MEASUREMENT OF CYTOTOXICITY
- Method: background growth inhibition;

Rationale for test conditions:

The bacterial reverse mutation test is commonly employed as an initial screen for genotoxic activity and, in particular, for point mutation-inducing activity.

Evaluation criteria:

The colonies were counted visually and the numbers were recorded. A validated spread-sheet software (Microsoft Excel®) was used to calculate mean values and standard devia-tions of each treatment, solvent control and positive control.
The mean values and standard deviations of each threefold determination was calculated as well as the increase factor f(l) of revertant induction (mean revertants divided by mean spontaneous revertants) of the test item solutions and the positive controls. Additionally, the absolute number of revertants (Rev. Abs.) (mean revertants less mean spontaneous revertants) was given.
A substance is considered to have mutagenic potential, if a reproducible increase of re-vertant colonies per plate exceeding an increase factor of 2 in at least one strain can be observed. A concentration-related increase over the range tested is also taken as a sign of mutagenic activity.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium, other: TA97a

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not applicable

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not applicable

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not applicable

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not applicable

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
none noted

Ames test:
- Signs of toxicity
no
- Individual plate counts / Mean number of revertant colonies per plate and standard deviation
See tables below

HISTORICAL CONTROL DATA (with ranges, means and standard deviation, and 95% control limits for the distribution as well as the number of data)
- Positive historical control data: See tables below
- Negative (solvent/vehicle) historical control data: See tables below

Applicant's summary and conclusion

Conclusions:

The study was conducted under GLP according to OECD guideline 471 on the registered substance itself. The method is to be considered scientifically reasonable with no deficiencies in documentation or any deviations, the validity criteria are fulfilled, positive and negative controls gave the appropriate response.
The test item Yucca schidigera, ext. showed no increase in the number of revertants in all bacteria strains in both experiments.
Based on the results of this study it is concluded that Yucca schidigera, ext. is not mutagenic in the Salmonella typhimurium test strains TA97a, TA98, TA100, TA102 and TA1535 in the absence and presence of metabolic activation under the experimental conditions in the present study.

Executive summary:

Two valid experiments were performed according to OECD TG 471 under GLP.

The study procedures described in this report were based on the most recent OECD and EC guidelines.

The test item Yucca schidigera, ext. was tested in the Salmonella typhimurium reverse mutation assay with five strains of Salmonella typhimurium (TA97a, TA98, TA100, TA102 and TA1535). The test was performed in two experiments in the presence and absence of metabolic activation, with +S9 standing for presence of metabolic activation, and –S9 standing for absence of metabolic activation.

 

Experiment 1:

In the first experiment, the test item (dissolved in demin. water) was tested up to concentrations of 5000 µg/plate in the absence and presence of S9-mix in the strains TA97a, TA98, TA100, TA102 and TA1535 using the plate incorporation method.

The test item showed no precipitates on the plates at any of the concentrations.

The bacterial background lawn was not reduced at any of the concentrations and no relevant decrease in the number of revertants was observed in all bacteria strains. The test item showed no signs of toxicity towards the bacteria strains in both the absence and presence of metabolic activation.

The results of this experiment showed that none of the tested concentrations showed a significant increase in the number of revertants in all tested strains, in the presence and the absence of metabolic activation.

 

Experiment 2:

Based on the results of the first experiment, the test item was tested up to concentrations of 5000 µg/plate in the absence and presence of S9-mix in all bacteria strains using the pre-incubation method.

The test item showed no precipitates on the plates at any of the concentrations.

The bacterial background lawn was not reduced at any of the concentrations and no relevant decrease in the number of revertants was observed in all bacteria strains. The test item showed no signs of toxicity towards the bacteria strains in both the absence and presence of metabolic activation.

The results of this experiments showed that the test item caused no increase in the number of revertants in all bacteria strains compared to the solvent control, in both the absence and presence of metabolic activation.

The test item did not induce a dose-related increase in the number of revertant colonies in all strains, in the presence and absence of metabolic activation.

 

Based on the results of this study it is concluded that Yucca schidigera, ext. is not mutagenic in the Salmonella typhimurium strains TA97a, TA98, TA100, TA102 and TA1535 in the absence and presence of metabolic activation under the experimental conditions in this study.