Sandalwood, 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:

2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

5-(2,3-dimethyltricyclo[2.2.1.02,6]hept-3-yl)-2-methylpent-2-en-1-ol, stereoisomer

EC Number:

204-102-8

EC Name:

5-(2,3-dimethyltricyclo[2.2.1.02,6]hept-3-yl)-2-methylpent-2-en-1-ol, stereoisomer

Cas Number:

115-71-9

Molecular formula:

C15H24O

IUPAC Name:

5-(2,3-dimethyltricyclo[2.2.1.0~2,6~]hept-3-yl)-2-methylpent-2-en-1-ol

Constituent 2

Reference substance name:

[1S-[1α,2α(Z),4α]]-2-methyl-5-(2-methyl-3-methylenebicyclo[2.2.1]hept-2-yl)-2-penten-1-ol

EC Number:

201-027-2

EC Name:

[1S-[1α,2α(Z),4α]]-2-methyl-5-(2-methyl-3-methylenebicyclo[2.2.1]hept-2-yl)-2-penten-1-ol

Cas Number:

77-42-9

Molecular formula:

C15H24O

IUPAC Name:

2-methyl-5-(2-methyl-3-methylenebicyclo[2.2.1]hept-2-yl)pent-2-en-1-ol

Constituent 3

Reference substance name:

(Z)-5-[(6R)-4,6-dimethyl-6-bicyclo[3.1.1]hept-3-enyl]-2-methylpent-2-en-1-ol

Cas Number:

176777-61-0

Molecular formula:

C15H24O

IUPAC Name:

(Z)-5-[(6R)-4,6-dimethyl-6-bicyclo[3.1.1]hept-3-enyl]-2-methylpent-2-en-1-ol

Constituent 4

Reference substance name:

(E)-(R)-(+)-5-(2,3-dimethyltricyclo[2.2.1.0^2,6]hept-3-yl)-2-methyl-2-penten-1-ol

Cas Number:

14490-17-6

Molecular formula:

C15H24O

IUPAC Name:

(E)-(R)-(+)-5-(2,3-dimethyltricyclo[2.2.1.0^2,6]hept-3-yl)-2-methyl-2-penten-1-ol

Constituent 5

Reference substance name:

2-​Hepten-​1-​ol, 2-​methyl-​6-​(4-​methylphenyl)​-​, (2Z)​-

Cas Number:

122442-36-8

Molecular formula:

C15H22O

IUPAC Name:

2-​Hepten-​1-​ol, 2-​methyl-​6-​(4-​methylphenyl)​-​, (2Z)​-

Test material form:

liquid

Method

Target gene:

E. coli WP2 uvrA (cat #72-188L) T/PE
S. typh. TA-97a (cat #71-097L) his D 6610
S. typh. TA-1535 (cat #71-1535L) his G 46
S. typh. TA-98 (cat #71-098L) his D 3052
S. typh. TA-100 (cat #71-100L) his G 46

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 97

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1535

Species / strain 3

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 4

Species / strain / cell type:

S. typhimurium TA 100

Species / strain 5

Species / strain / cell type:

E. coli WP2 uvr A

Test concentrations with justification for top dose:

Five concentrations (0.005, 0.01, 0.05, 0.1 and 0.5 µL/plate) of the test article were tested in each of five bacterial tester strains.
Two sets of culture plates were dosed per concentration (+S9 and -S9).
A vehicle control and positive controls specific to each bacterial strain were treated in a similar manner as the test article concentrations.

Vehicle / solvent:

Dimethyl sulfoxide (DMSO), Lot #112509 and 133317

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Remarks:

without S9

Positive control substance:

methylmethanesulfonate

other: Acridine 6-chloro-9-(3-((2-chloroethyl)amino) propyl)amino-2-methoxy dihydrochloride ( S. typh. TA-97a Sodium azide (S. typh. TA-1535 and S. typh. TA-100) Daunomycin hydrochloride (S. typh. TA-98 )

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Remarks:

with S9

Positive control substance:

other: 2-Aminoanthracene

Details on test system and experimental conditions:

Tester strains were dosed in triplicate with five concentrations of the test article. Six plates each were dosed with the vehicle control and the positive control specific for each tester strain.
Bacterial cultures were inoculated by the addition of a lyophilized disk of each tester strain to Oxoid No.2 nutrient broth (Molecular Toxicology, Inc. (Moltox) Boone, NC, cat. #26-555). Ampicillin was added to the nutrient broth to ensure the retention of R-factor plasmid in tester strains TA-97a, TA-98 and TA-100. The cultures were incubated at 37 °C ±2 °C with agitation. The cultures were used after they reached the late exponential growth phase as determined by absorbance readings at 600 nm.

Evaluation criteria:

Plates were scored based on the number of revertant colony-forming units present per plate. The number of revertants of each test article plate were averaged and plotted versus concentration of the test article. The mean number of revertants of each dose was divided by the mean for the vehicle control value to obtain a ratio to vehicle. In evaluating the data, cytotoxicity of the test article as well as quality checks of the assay were taken into account.
In general, a 2-fold increase with or without metabolic activation is considered a positive response. Dose-related increases approaching a 2-fold increase are deemed equivocal.
A negative result is determined by the absence of a dose-related increase in all five tester strains, again taking into account cytotoxicity of the test article as well as the quality checks of the assay.
Positive results from the bacterial reverse mutation test indicate that the substance induces point mutations by base substitutions or frame shifts in the genome of either Salmonella typhimurium and/or Escherichia coli. Negative results indicate that under the test conditions, the test substance is not mutagenic in the tested species.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

E. coli WP2 uvr A

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

Test results 2

Key result

Species / strain:

S. typhimurium TA 97

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

no significant increase or dose-dependent increase of the number of revertants in the tester strain treated with the test article in the presence or absence of S9

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

no significant increase or dose-dependent increase of the number of revertants in the tester strain treated with the test article in the presence or absence of S9

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

no significant increase or dose-dependent increase of the number of revertants in the tester strain treated with the test article in the presence or absence of S9

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

no significant increase or dose-dependent increase of the number of revertants in the tester strain treated with the test article in the presence or absence of S9

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

In the main test, the test article even at the highest dosing concentration (0.5 µL/plate) did not cause severe or moderate cytotoxicity to tester strain WP2 uvrA.
In the Independent Repeat Assay including the Guideline-recommended maximum test concentration for soluble non-cytotoxic test article (5 µL/plate),no reduction or clearing of the bacterial background lawn was observed, indicating no or minimal cytotoxicity of the test article under test conditions. There was no significant increase or dose-dependent increase of the number of revertants in WP2 uvrA treated with the test article in the presence or absence of S9.
All Positive and Negative Control values were within acceptable ranges, and all criteria for a valid study were met. The results confirmed that the test article did not cause mutation to WP2 uvrA.

Applicant's summary and conclusion

Conclusions:

Under test conditions, test article TFS plantation-grown Indian sandalwood (santalum album) oil, Batch# APIS0-130608SD/SA, did not have mutagenicity potential in the Bacterial Reverse Mutation Test.

Executive summary:

Test article TFS plantation-grown Indian sandalwood (santalum album) oil, Batch# APISO-130608SD/SA, in the vehicle, Dimethyl sulfoxide, was tested in a Bacterial Reverse Mutation Assay.

The test article showed severe cytotoxicity to tester strain TA-100 at a dose range of 1 to 5µL/plate with S9 and at a dose range of 0.5 to 5µL /plate without S9. In the main test, the test article showed severe to moderate/mild cytotoxicity to all S. typhimurium strains (TA 97a, TA1535, TA98, TA100) at several top concentrations, but not to E Coli WP2 uvrA. The test article at 0.005 to 0.5µL /plate, with or without S9, did not cause a significant increase or a dose-dependent increase of the number of revertants of any bacterial tester strain, indicating that the test article is negative for mutagenicity in the Bacterial Reverse Mutation Assay.

In the independent repeat assay (confirmatory test), the test article at 0.05 to 5µL/plate, with or without S9, did not cause a significant increase or a dose-dependent increase of the number of revertants of tester strain WP2 uvrA, and showed no/minimal cytotoxicity to WP2 uvrA, indicating that the test article is negative for mutagenicity to this strain.

Conclusion: Under test conditions, test article TFS plantation-grown Indian sandalwood (santalum album) oil, Batch# AP1S0-130608SD/SA, did not have mutagenicity potential in the Bacterial Reverse Mutation Test.