(3E)-1,7,7-trimethyl-3-(4-methylbenzylidene)bicyclo[2.2.1]heptan-2-one

Additional ecotoxological information

Administrative data

Endpoint:

additional ecotoxicological information

Remarks:

In vitro experimental information for endocrine activity discussion.

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Some details in the methods not provided

Justification for type of information:

Experimental information for endocrine activity discussion.

Data source

Reference

Reference Type:

publication

Title:

Comparison of in vitro and in vivo estrogenic activity of UV filters in fish

Author:

Kunz PY, Galicia HF, Fent K

Year:

2006

Bibliographic source:

Toxicological Sciences 90(2): 349-361

Materials and methods

Principles of method if other than guideline:

In vitro oestrogenic activity in a yeast assay transfected with the rainbow trout ERα (rtERa).
-Cell line: Liquid culture of recombinant yeast (Saccharomyces cerevisiae) expressing the estrogen receptor of rainbow trout (rtERa) that was provided by F. Pakdel, University of Rennes
-rtERalpha expression: When an active ligand (i.e., 17beta-oestradiol) binds to the receptor, beta-galactosidase is synthesized and secreted into the medium, leading to a catalytic hydrolysis of o-nitrophenyl-beta-D-galactopyranosid (ONPG) and resulting in the development of a yellow colour, which is measured as absorbance at 405 nm.

GLP compliance:

not specified

Remarks:

Published study from a peer-reviewed journal.

Type of study / information:

Investigation of the oestrogenic activity of 4-methylbenzylidene camphor, in a yeast assay transfected with the oestrogen receptor α of the rainbow trout ERα (rtERα).

Test material

Test material information

Constituent 1

Reference substance name:

(3E)-1,7,7-trimethyl-3-(4-methylbenzylidene)bicyclo[2.2.1]heptan-2-one

EC Number:

701-394-3

Cas Number:

1782069-81-1

Molecular formula:

C18H22O

IUPAC Name:

(3E)-1,7,7-trimethyl-3-(4-methylbenzylidene)bicyclo[2.2.1]heptan-2-one

Specific details on test material used for the study:

Obtained from Merck (Glattbrugg, Switzerland) >99% purity.

Results and discussion

Any other information on results incl. tables

4-methylbenzylidene camphor did not result in any transactivational effects in the rt ERα assay.

Applicant's summary and conclusion

Conclusions:

No oestrogenic activity of 4-methylbenzylidene camphor.

Executive summary:

Kunz et al. (2006) investigated the in vitro oestrogenic activity of 4-methylbenzylidene camphor, in two yeast transactivational assays. A recombinant yeast (Saccharomyces cerevisiae) was employed, which was stably transfected with the rainbow trout ERα (rtERα). The paper also describes effects in a similar yeast assay transfected with human hERα which is detailed in Section 7.12, and the in vivo effects of 4-methylbenzylidene camphor on vitellogenin induction which is detailed in Section 6.1.2.

 

The assay uses a stably transfected rtERα, and is based on the induction of β-galactosidase, following activation of the receptor which leads to a colour change of the substrate. The tested concentration range is not specifically stated, but the figures indicate that the substances were tested in the range of 10^-9 to 10^-2 M (0.00025-2543 mg/L). Cytotoxicity, manifest by significantly reduced yeast growth or cell lysis, was monitored for and determined by absorbance measurement at 620 nm. The results are reported based on expressed as a percentage of the maximal effect produced by the dose–response curve of 17β-estradiol. 4-methylbenzylidene camphor did not result in any transactivational effects in the hERα assay indicating that it did not have any agonistic oestrogenic activity. This was consistent with the results from other endpoints measured in the same study.

 

This study was assigned a reliability score of 2: reliable with restrictions. The study was not conducted according to an international guideline, but used a well-established yeast based assay. The study was well-documented and scientifically acceptable.