Panthenol , DL-form

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

In the key study in a bacterial reverse mutation assay, no mutagenic activity was detected with DL-Panthenol. DL-Panthenol was not tested for chromosome aberration properties. A read across approach was performed with te structural supporing substance DL-Ethyl Panthenol which showed no clastogenic properties in a human lymphocyte assay. DL-Panthenol was not tested for cell gene mutation activity. A read across approach was performed with the structural supporting substance DL-Ethyl Panthenol which showed no cell gene mutation in a HPRT test with Chinese Hamster V79 cells. Based on the results obtained DL-Panthenol was not considered to show mutagenic activity.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998-07-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

July 21, 1997

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

December 1992

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

his operon

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

not applicable

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced rat liver S-9

Test concentrations with justification for top dose:

20, 100, 500, 2500, 5000 µg/plate (SPT and PIT)

Vehicle / solvent:

- Vehicle used: water
- Justification for choice of solvent/vehicle: Due to the good solubility of the test substance in water, water was selected as the vehicle.

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene, N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro-o-phenylendiamine, 9-aminoacridine, 4-nitroquinoline-N-oxide

Remarks:

positive control substance depending on tester strain and activation conditions

Details on test system and experimental conditions:

METHOD OF APPLICATION: plate incorporation
DURATION
- Exposure duration: 48 - 72 h, 37°C, in the dark
NUMBER OF REPLICATIONS: 3 plates per dose or per control
DETERMINATION OF CYTOTOXICITY
- Method: decrease in the number of revertants, clearing or diminution of the background lawn (= reduced his- or trp+ background growth), reduction in the titer

METHOD OF APPLICATION: preincubation
DURATION
- Preincubation period: 20 min., 37°C
- Exposure duration: 48 - 72 h, 37°C, in the dark
NUMBER OF REPLICATIONS: 3 plates per dose or per control
DETERMINATION OF CYTOTOXICITY
- Method: decrease in the number of revertants, clearing or diminution of the background lawn (= reduced his- or trp+ background growth), reduction in the titer

Evaluation criteria:

Acceptance criteria
Generally, the experiment is to be considered valid if the following criteria are met:
The number of revertant colonies in the negative controls was within the normal range of the historical control data for each tester strain.
The sterility controls revealed no indication of bacterial contamination.
The positive control articles both with and without S-9 mix induced a significant increase in the number of revertant colonies within the range of the historical control data.
The titer of viable bacteria was >10E9/ml.

Evaluation criteria
The test chemical is considered positive in this assay if the following criteria are met:
A dose-related and reproducible increase in the number of revertant colonies, i.e. about doubling of the spontaneous mutation rate in at least one tester strain either without S-9 mix or after adding a metabolizing system.
A test substance is generally considered nonmutagenic in this test if:
The number of revertants for all tester strains were within the historical negative control range under all experimental conditions in two experiments carried out independently of each other.

Statistics:

no data

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

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

Positive controls validity:

valid

Additional information on results:

No increase in the number of revertants was observed with any tester strain at any concentration in the absence and presence of metabolic activation. No bacteriotoxicity was observed. The test substance was completely soluble in the vehicle; no precipitation was noted.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results (migrated information):
negative

According to the results of the present study, the test substance DL-Panthenol is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay under the experimental conditions chosen here.

Executive summary:

The substance DL-Panthenol was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of several bacterial strains, i.e. Salmonella typhimurium and Escherichia coli, in a reverse mutation assay according to OECD 471 and under GLP.

Standard plate test (SPT) and Preincubation Test (PIT) both with and without metabolic activation with liver homogenate of Aroclor 1254 -pretreated male Sprague-Dawley rats were applied. Two independent experiments were carried out: 1st Experiment Strains: TA 1535, TA 100, TA 1537, TA 98, E. coli WP2 uvrA Doses: 0; 20; 100; 500; 2500 and 5000 µg/plate Vehicle: Water Type of test: Standard plate test with and without S-9 mix Number of plates: 3 test plates per dose or per control 2nd Experiment Strains: TA 1535, TA 100, TA 1537, TA 98, E. coli WP2 uvrA Doses: 0; 20; 100; 500; 2500 and 5000 µg/plate Vehicle: Water Type of test: Preincubation test with and without S-9 mix Number of plates: 3 test plates per dose or per control Negative controls treated with the vehicle (water) and positive controls treated with 2-aminoanthracene, N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro-o-phenylendiamine, 9-aminoacridine, or 4-nitroquinoline-N-oxide were included in each replicate.

No increase in the number of revertants was observed with any tester strain at any concentration in the absence and presence of metabolic activation. No bacteriotoxicity was observed. The test substance was completely soluble in the vehicle; no precipitation was noted.

According to the results of the present study, DL-Panthenol was considered to be not mutagenic.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

Bacterial reverse mutation assay:

The substance DL-Panthenol was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of several bacterial strains, i.e. Salmonella typhimurium and Escherichia coli, in a reverse mutation assay. Standard plate test (SPT) and Preincubation Test (PIT) both with and without metabolic activation with liver homogenate of Aroclor 1254 -pretreated male Sprague-Dawley rats were applied. Two independent experiments were carried out: 1st Experiment Strains: TA 1535, TA 100, TA 1537, TA 98, E. coli WP2 uvrA Doses: 0; 20; 100; 500; 2500 and 5000 µg/plate Vehicle: Water Type of test: Standard plate test with and without S-9 mix Number of plates: 3 test plates per dose or per control 2nd Experiment Strains: TA 1535, TA 100, TA 1537, TA 98, E. coli WP2 uvrA Doses: 0; 20; 100; 500; 2500 and 5000 µg/plate Vehicle: Water Type of test: Preincubation test with and without S-9 mix Number of plates: 3 test plates per dose or per control Negative controls treated with the vehicle (water) and positive controls treated with 2-aminoanthracene, N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro-o-phenylendiamine, 9-aminoacridine, or 4-nitroquinoline-N-oxide were included in each replicate. According to the results of the present study, DL-Panthenol was considered to be not mutagenic.

Mammalian cell gene assay:

Read across to the supporting substance DL-Ethylpanthenol was done. For justification of read across please refer to the attachment in IUCLID5 section 13. In a mammalian cell gene mutation assay, in chinese hamster V79 cells cultured in vitro were exposed for 4 hours to DL-Ethyl Panthenol, at concentrations of 150, 300, 600, 1200, 2400 µg/mL in the presence and absence of mammalian metabolic activation S9 mix (rat liver). In a second test the chinese hamster V79 cell cultures were exposed to the same concentrations for 24 hours in the absence of metabolic activation.   DL-Ethyl Panthenol was tested up to concentrations of 2400 µg/mL (approx 10 mM). No relevant cytotoxic effect was observed in the first experiment as relative cloning efficiency 1 did not go below 50 %. In the second experiment cytotoxicity was noted at 300 µg/mL and above. No substantial dose dependent increase of the mutation frequency exceeding the threshold of three times the mutation frequency of the corresponding solvent control occured with and without metabolic activation. Furthermore there was no dose dependent trend even below the threshold mentioned above as indicated by the missing statistical significance. Therefore, the data of this study are judged as non-mutagenic.  The positive controls induced a distinct increase in mutant colonies and thus, showed the sensitivity of the test and the activity of the metabolic activation system.   This study is classified as acceptable.  This study fulfills the requirements of the Guideline OECD 476 for in vitro mutagenicity (mammalian forward gene mutation) data. 

Chromosome aberration assay:

Read across to the supporting substance DL-Ethylpanthenol was done. For justification of read across please refer to the attachment in IUCLID5 section 13. DL-Ethyl Panthenol was assessed as to its ability to induce chromosomal aberrations in human peripheral blood lymphocytes in vitro.Without metabolic activation doses between 333 and 5000 µg/mL were tested after 24 hours continous treatment. With metabolic activation (S9- mix, rat) doses between 1000 and 5000 µg/mL were tested after a 3 hours pulse treatment. Two independent experiments were performed at a fixation period of 24 hours. Additionally the highest dose of 5000 µg/mL was tested in one experiment at a fixation period of 48 hours (i.e. after a 48 h continuous treament in absence and a 3 hours pulse treatment in presence of S9- mix).

The sensitivity of the test system and the activity of the metabolic activation were demonstrated by using the direct acting mutagen mitomycin-C (MMC-C) and the promutagen cyclophosphamide (CP) as positive controls. Both substances increased significantly the rate of chromosome aberrations.

The highest dose assayed was the maximal recommended one. Cytotoxicity as measured by reductions in the mitotic indices (MI) was observed after continuous (24 and 48 hours) exposures to DL-Ethyl Panthenol in both experiments. Exposure to DL-Ethyl Panthenol did not raise the rate of cells with chromosome aberrations.

Based on the close structural similarity of D-and DL-Panthenol and due to the metabolism of DL Ethyl Panthenol to Panthenol it can be assumed that also DL-Panthenol is neither genotoxic nor mutagenic.

Justification for selection of genetic toxicity endpoint
GLP and guideline study.

Justification for classification or non-classification

Based on the results obtained from the key study and the results of tests performed with the supporting substance, DL-Panthenol was not classified and labeled according to Regulation (EC) No 1272/2008 (CLP) and Directive 67/548/EEC (DSD).