2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one

Endpoint summary

Additional information

Three in vitro assays were performed to evaluate the genotoxicity of the test substance. At first, the material 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 (TA 1535, TA 100, TA 1537, TA 98 and E. coli WP2 uvrA). The test item was applied at concentrations of 33 μg - 5000 μg/plate in presence and absence of a metabolic activation system (S9 mix). A relevant increase in the number of his+ or trp+ revertants was not observed in the standard plate test or in the preincubation test either without S9 mix or after the addition of a metabolizing system.

The objective of the second assay was to evaluate the ability of the test substance to induce chromosomal aberrations in cultured Chinese hamster lung fibroblasts (V79) with and without exogenous metabolic activation. The test article was dissolved in DMSO. Replicate cultures of CHO cells were incubated with 20 to 200 µg/ml for 4.0 hours with and without S9 and harvested at 11.5 hours after the initiation of treatment. In the absence and the presence of S9 mix the aberration rates were statistically significant and biologically relevant increased after treatment with 120 µg/mL. Also, the number of cells carrying exchanges was distinctiy increased. Although these observations have been made at cytotoxic concentrations they have to be regarded as biologically relevant.

At last, the test material was assessed for its potential to induce gene mutations at the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus in Chinese hamster ovary (CHO) cells in vitro. Two independent experiments were carried out, both with and without the addition of liver S9 mix from induced. Based on the solubility properties of the test substance and according to an initial rangefinding cytotoxicity test doses up to 250 µg/ml were tested in presence and absence of a metabolic activation system. On the basis from the results of the present study, the test substance did not cause any relevant increase in the mutant frequencies both without S9 mix.

At last an in vivo study was performed to investigate the potential of the test item to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the mouse. The material, dissolved in corn oil, was administered singly at concentrations of 500, 1000 and 2000 mg/kg bw. 24h and 48h after administration the bone marrow cells were collected for micronuclei analysis. To investigate a cytotoxic effect of the compound the ratio between polychromatic and normochromatic erythrocytes was determined. After treatment the number of PCEs was not substantially decreased as compared to the vehicle control thus indicating that the substance did not exert a cytotoxic effect in the bone marrow. In comparison to the corresponding vehicle controls there was no biologically relevant or statistically significant enhancement in the frequency of the detected micronuclei at any preparation interval after administration of the test item and with any dose level used. In conclusion, the test item did not induce micronuclei and the test material is considered to be non-mutagenic in this micronucleus assay.

The test item did not induce mutations in bacteria or mammalian cells or chromosome aberrations in mammalian cells in vitro. An indiction of micronuclei in mice after oral treatment was also not observed. Therefore, the substance is not considered to be genotoxic under the conditions of these tests.

Short description of key information:
The test item was not mutagenic in a bacterial gene mutation assay but indiuced a positive (clastogenic) response in an in-vitro chromosome aberration test. The in-vivo micronucleus test in mice was negative and did not confirm the clastogenic effect from the in-vitro test.
No mutagenic potential was evident in an in-vitro gene mutation test in mammalian cells.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

The available studies are considered reliable and suitable for classification purposes under 67/548/EEC. As a result the substance is not considered to be classified for genotoxicity under Directive 67/548/EEC.

 

 

Classification, Labeling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is not considered to be classified for genotoxicity under Regulation (EC) No. 1272/2008.