Benzophenone

Toxicity to reproduction: other studies

Administrative data

Endpoint:

toxicity to reproduction: other studies

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No guideline was followed but scientifically defensible approach was used to conduct the study.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2000

Materials and methods

Principles of method if other than guideline:

Estrogenicity was assessed using the Saccharomyces cerevisiae-based Lac-Z reporter assay (Glaxo Wellcome-derived S. cerevisiae assay) and was reported as the logarithm of the inverse of the 50% molar b-galactosidase activity (log[EC50-1]). The strain used in this assay constitutively expresses the gene for the a-human estrogen receptor. On a separate expression plasmid, the estrogen-responsive sequences control the expression of the Lac-Z reporter gene. Xenoestrogens interact with the bound receptor on the hybrid promoter to initiate transcription of the genes resulting in the production of b-galactosidase. The b-galactosidase activity is measured colorimetrically by the yellow chromogen chlorophenol red-b-D-galactopyranoside being metabolized into phenol red. The latter is measured with a microplate reader as absorbency at 540 nm. Absorbency at 610 nm was also used to measure cell density and mortality. If mortality occurred, results were removed from further analysis.

GLP compliance:

not specified

Type of method:

in vitro

Test material

Test material information

Constituent 1

Reference substance name:

Benzophenone

EC Number:

204-337-6

EC Name:

Benzophenone

Cas Number:

119-61-9

Molecular formula:

C13H10O

IUPAC Name:

benzophenone

Details on test material:

- Name of test material (as cited in study report): Benzophenone
- Purity: ≥ 95%

Test animals

Species:

other: In-vitro

Details on test animals or test system and environmental conditions:

In-vitro: Saccharomyces cerevisiae cultures.

Administration / exposure

Route of administration:

other: In-vitro

Details on exposure:

Fresh stock solutions were prepared in ethanol for each replicate. The test compound was serially diluted for a total of 12 concentrations in ethanol, with 10 ml of each concentration being added to a well of a 96-well plate and allowed to dry. After drying, 200 ml of medium containing
~ 5*10E+03 yeast cells/ml and chlorophenol red-b-D-galactopyranoside were added to each well. Plates were wrapped in parafilm to prevent evaporation. Plates were incubated at 30 ± 1 ºC and agitated daily. Following 3, 5 and 7 d of incubation, absorbency at 540 nm was recorded.

Analytical verification of doses or concentrations:

not specified

No. of animals per sex per dose:

All substances were evaluated in duplicate with a minimum of three replicates.

Details on study design:

Each replicate included the positive control 17-b-estradiol and the negative control ethanol.

Statistics:

The EC50 (the concentration eliciting an activity equal to 50% of the positive control 17-b-estradiol) was determined for each compound and each time point by Probit Analysis of Statistical Analysis System software. The dependent variable was the absorbency normalized as percentage of control. The independent variable was the toxicant concentration in grams per liter. The EC50 values were converted to molar units prior to being reported.

Results and discussion

Observed effects

Benzophenone was non-active in for estrogenic activity in the recombinant yeast assay with. The LC50 was determined to be 5.48e-04M.

Applicant's summary and conclusion

Conclusions:

Benzophenone was non-active in for estrogenic activity in the recombinant yeast assay with. The LC50 was determined to be 5.48e-04M.

Executive summary:

Estrogenicity was assessed using the Saccharomyces cerevisiae-basedLac-Z reporter assay and was reported as the logarithm of the inverse of the 50% molar b-galactosidase activity (log[EC50-1]). There is a general trend of increase in estrogenicity with increased substituent size. The EC50 (the concentration eliciting an activity equal to 50% of the positive control 17-b-estradiol) was determined for each compound and each time point by Probit Analysis of Statistical Analysis System software. Benzophenone was non-active for estrogenic activity and the LC50 was determined to be 5.48e-04M.