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Toxicity to reproduction: other studies

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Administrative data

Endpoint:
toxicity to reproduction: other studies
Type of information:
experimental study
Adequacy of study:
key study
Study period:
During 2001-11-05 and 2002-03-19
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
Except for the following deviations, this study was conducted in compliance with the OECD Principles of Good Laboratory Practice as revised in 1997 (ENV/MC/CHEM (98) 17) and with the German Principles of Good Laboratory Practice (Bundesgesetzblatt Part I, No. 21 of May 14, 2001). The deviations were as folIows: The expiry date (stability) of the test article was provided by the sponsor after completion of the study. Homogeneity and stability of the test substance in the formulation for administration were not determined. Homogeneity was ensured by mixing and checked visualIy. The test substance characteristics were not suggestive of rapid reaction with the formulation agents.
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: This study was conducted in accordance with: OECD, Protocol of the conduct of the rodent uterotrophic assay, Draft protocol B - Immature female rats with sub-cutaneous administration (April 20, 2000).
Principles of method if other than guideline:
not applicable
GLP compliance:
yes
Type of method:
in vivo

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
Wistar
Sex:
female
Details on test animals and environmental conditions:
Experimental animals
The study was conducted in juvenile female rats - animals recommended in the OECD protocol for these validation studies. At the start of the study, the animals were 19 days old and had starting weights of 29 - 36 g.
SPF-bred Wistar rats of the strain HsdCpb:WU from the Harlan Winkelmann GmbH Experimental Animal Breeders in Borchen, District of Paderborn were used.

Housing conditions
During the adaptation period, the animals were conventionally kept in polycarbonate cages type III (one foster dam with six or seven juvenile animals per cage). The cages ware not changed during the adaptation period.
During the test period, the animals were conventionally kept in polycarbonate cages type III (three animals per cage). Low-dust wood shavings type BK 8/15 (Supplier: Ssniff, Spezialdiäten GmbH, Soest/ Westphalia) were used as litter. The wood shavings were spot-checked tor contaminants levels and the records are filed at Bayer AG. The analytical results afforded no evidence for an effect on the study objective.
Cages and bedding material were not changed during the test period.
The cages containing the experimental animals ware placed on racks, separated by groups, in ascending animal number order. All animals taking part in this study were kept in the same animal room.

Environmental conditions
The environmental conditions in the animal room were standardized as follows:
room temperature: 22 ± 2°C
relative humidity: approx. 55 ± 5%
ligh/dark cycle: 12-hour artificial lighting
air exchange rate: approx. 10 times per hour
Occasional deviations from these conditions occurred, e.g. due to cleaning the animal room. They had no perceptible effect on the study routine.

Administration / exposure

Route of administration:
subcutaneous
Type of inhalation exposure (if applicable):
other: not applicable
Vehicle:
corn oil
Details on exposure:
Groups of 6 juvenile female rats of the strain HsdCpb:WU were administered isopentyl p-methoxycinnamate once a day at levels of 0 (untreated), 0 (vehicle control) 200 and 1000 mg/kg body weight subcutaneously for a period of three days. In two aditional groups of 6 juvenile female rats each the females were treated once a day fo 3 consecutive days with 0.3 and 1.0 µg/kg 17α-ethinylestradiol (positive control). The vehicle used for all groups except untreated control was corn oil.
Analytical verification of doses or concentrations:
no
Details on analytical verification of doses or concentrations:
no data available
Duration of treatment / exposure:
3 days
Frequency of treatment:
once a day
Duration of test:
3 days
Doses / concentrations
Remarks:
Doses / Concentrations:
Dose levels of 200 and 1000 mg/kg Neo Heliopan E1000 were included in this study.
Basis:
no data
No. of animals per sex per dose:
6 female rats per dose group
Control animals:
yes, concurrent no treatment
yes, concurrent vehicle
Details on study design:
The study methodology conformed to the OECD Validation work on in-vivo uterotrophic screening assay, OECD protocol of the conduct of the rodent uterotrophic assay, Draft protocol B - Immature female rats with sub-cutaneous administration (April 20, 2000).
Groups of 6 juvenile female rats were administered the test substance once a day at levels of 200 and 1000 mg/kg body weight subcutaneously for a period of three days. 17α-ethinylestradiol in doses of 0.3 and 1.0 μg/kg body weight served as positive control. For the negative control one animal group received the vehicle (corn oil) and one animal group remained untreated. At termination of the study the animals were necropsied and the organ weights of the uteri (wet and blotted) were determined.
Statistics:
The results of the animal observations, organ, body and feed weights were collected and processed on-line and off-line.
The quantitative results for individual animals were used to calculate arithmetic group means and standard deviations. The results for the groups that received the test substance were compared with those for the vehicle contral group. The vehicle contral group was additionally compared to the untreated control group. Significant differences were indicated by '+' for p=< 0.05 and '++' for p=< 0.01.
The statistical evaluation of data related to body and organ weights as well as feed intake is performed using SAS routines.
Statistical evaluation on body weight and organ weight data were done using the Dunnet test in connection with a variance analysis. Relative organ w eights are submitted to a logarithmic transformation prior to the statistical analysis.
In case of numbers of values too low to calculate test statistics this is indicated by '0' or '-' in the tables shown in the results section and by 'ne' (not calculated) or '0' in the tables of the Annex. The individual results listed in the Annex to this report have been rounded off. Calculation of means and variances was based in part on the non-rounded original values. Some of the values in the tables of individual body weights may be missing. This may be the consequence of a technical defect which occured during on-line data collection or of a value which can not be listed (because of an error in weighing and a failure to meet printer format) or is unrealistic on account of a weighing error and deleted.

Results and discussion

Effect levels

Dose descriptor:
dose level:
Effect level:
> 1 000 mg/kg bw/day
Based on:
test mat.
Sex:
female
Basis for effect level:
other: Endpoint: Increase in uterine weight

Observed effects

Regarding state of health or general behaviour of the animals, there was no difference between the untreated and treated animals of all groups.
No treatment related mortality was observed.
No toxicologically significant effect on the feed intake was observed.
Body weights were not affected by treatment.
At necropsy, a dose-dependent enlargement of uteri and an increased uterine wet and bIotted weight were observed for the positive control group at 0.3 and 1.0 µg/kg 17α-ethinylestradioI. No effects on uterine weights were observed at 200 and 1000 mg/kg isopentyl p-methoxycinnamate.

Any other information on results incl. tables

not applicable

Applicant's summary and conclusion

Conclusions:
In conclusion, no estrogenic effects were detected in the uterotrophic assay on juvenile female rats at sub-cutaneous doses of 1000 mg isopentyl p-methoxycinnamate per kg bw and below.
Executive summary:

The dose-response of the test substance isopentyl p-methoxycinnamate following repeated subcutaneously administration was examined in an in-vivo uterotrophic screening assay (three-day treatment) using juvenile female Wistar rats.The study methodology conformed to the OECD Validation work on in-vivo uterotrophic screening assay, OECD, Protocol of the conduct of the rodent uterotrophic assay, Draft protocol B-Immature female rats with sub-cutaneous administration (April 20, 2000). Groups of 6 juvenile female rats of the strain HsdCpb:WU were administered isopentyl p-methoxycinnamate once a day at levels of 0 (untreated), 0 (vehicle control) 20 and 1000 mg/kg bwfor a period of three days. In two additional groups of 6 juvenile female rats, each of the females were treated once a day for 3 consecutive days with either 0.3 and 1.0 µg/kg 17alpha-ethinylestradiol (positive control). The vehicle used for all groups except untreated control was corn oil. Clinical observations were performed daily. Body weights ware determined daily. Feed intake was determined per group at termination (day 3). Gross necropsy (with uterus weights and tissue sampling) was performed on all animals at termination.

Regarding state of health or general behaviour of the animals, mortality, body weights, and feed intake, there was no difference between the untreated animals and animals treated with isopentyl p-methoxycinnamate.

No effects on uterine weight were observed at 200 and 1,000 mg/kg isopentyl p-methoxycinnamate. An enlargement of uterus was observed and increased uterine weights were determined at 0.3 and 1.0 µg/kg ethinylestradiol (positive control). In conclusion, no estrogenic effects were detected in the uterotrophic assay on juvenile female rats at sub-cutaneous doses of 1000 mg isopentyl p-methoxycinnamate per kg body weight and below.