Coumarin

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The purpose of this study, performed at the Huntingdon Research Centre, England, was to dtermine a suitable high dietary level of Coumarin, a food and cosmetic flavouring substance, for a long-term feeding study in rats following in utero exposure.
The high dietary level used in this study was based on findings by Griepentrog.
Treatment commenced on 1 February 1980 and ended on 16 May 1980.
This report contains all data generated during the study.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Coumarin

EC Number:

202-086-7

EC Name:

Coumarin

Cas Number:

91-64-5

Molecular formula:

C9H6O2

IUPAC Name:

2H-chromen-2-one

Test material form:

other: crystalline

Details on test material:

-Substance type: pure substance
-Physical state: White crystalline powder
-Lot/batch No: CA 78300/01
-Storage condition of test material: room tempeature

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Test animals
-Source: Charles River Laboratories, Portage, USA
-Age at arrival: 8 weeks
-Weight at study initiation: 50g
-Diet: Free access to Spratts Laboratory Animals Diet No.2( treated with the appropriate level of coumarin)
-Water: Free access to tap water
-Acclimation: The acclimation period is 7 days.
Environmental conditions:
-Temperature: 22℃
- Humidity: 50%
- Lighting control: 12 hours light and 12 hours dark per 24 hours.

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

Coumarin was administered by admixture with the diet. The required dietary concentrations were obtained by the dilution of premix prepared each
week. Control animals received normal(untreated) diet.

Details on mating procedure:

-Impregnation procedure: cohoused
-M/F ratio per cage: 1:2
-Length of cohabitation: 20days

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

No data. The doses were calculated based on the group mean food consumption

Duration of treatment / exposure:

Total duration of treatment 15 weeks

Frequency of treatment:

Daily

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
0 ppm
Basis:
nominal in diet
control

Doses / concentrations 2

Remarks:

Doses / Concentrations:
3000 ppm
Basis:
nominal in diet

Doses / concentrations 3

Remarks:

Doses / Concentrations:
3000/5000 ppm
Basis:
nominal in diet

Doses / concentrations 4

Remarks:

Doses / Concentrations:
5000 ppm
Basis:
nominal in diet

No. of animals per sex per dose:

8 males plus 16 females per dose

Control animals:

yes, concurrent no treatment

Positive control:

None

Examinations

Parental animals: Observations and examinations:

Detailed clinical observation:
Any reaction to treatment exhibited by the rats was recorded daily as to type, duration and animal affected.
Body weight: the weight of each rat was recorded one week before the commencement of treatment and at twice intervals thereafter.
Food consumption: The quantity of food consumed by each cage of rats was recorded and the group mean weekly intake per rat calculated.

Oestrous cyclicity (parental animals):

None

Sperm parameters (parental animals):

None

Litter observations:

Litter weight change:
Pups were weighed in total litters at birth, and at 4,7,11,14,18 and 21 days post partum.
Litter size
At birth, and at 4,7,11,14,18 and 21days, mean values were determined for both the total number of young and the number of viable and dead young.

Postmortem examinations (parental animals):

None

Postmortem examinations (offspring):

None

Statistics:

Statistical analysis of data for adults involved on the study was not attempted, as it was considered that bodyweight and food consumption data clearly indicated an effect. Statistical significance of intergroup differences occurring among the pups and litters was assessed using the Kruskal-Wallis test, excluding from the test group 3(3000/5000ppm coumarin) as this group was already sufficiently different from the norm to detract from the accuracy of the method.

Reproductive indices:

No. females mated
No. females not pregnant

Offspring viability indices:

The following reproductive parameters were evaluated statistically:
Viable litters at Day 21 post partum
Mortality during days 0-21

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

not examined

Histopathological findings: non-neoplastic:

not examined

Other effects:

effects observed, treatment-related

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

not examined

Details on results (P0)

Clinical findings: No clinical signs were observed that could clearly be related to treatment.
Mortality: There was no adult mortality during the study.
Food consumption: Probably as a result of unpalatability, food consumption of males and females was reduced in all groups of treated adult rats.
Bodyweight gain: Associated with the effect on food intake, growth of males and females of all adult treated groups was severely impaired. This effect was most marked among rats exposed to Coumarin at 5000 ppm or 3000/5000 ppm.
Efficiency of food utilisation: The efficiency of food utilisation of all groups of treated adult rats was markedly inferior to that of the controls .

Effect levels (P0)

Dose descriptor:

NOAEL

Effect level:

> 333 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: Based on no of mated/ pregnant

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Details on results (F1)

Viability of litters: The number of viable litters reaching 21 days age produced by rats exposed to 3000/5000 ppm was markedly less than that of the controls, although the number of viable litters produced by dams exposed to 3000 or 5000 ppm was similar to that of the controls .
Mean litter size at birth: The mean litter sizes of rats receiving 3000 or 5000 ppm (but not 3000/5000 ppm) were marginally lower than those of the controls.
Bodyweight gain of pups: The growth of pups of all treated groups was severely retarded by exposure to Coumarin.

Overall reproductive toxicity

Reproductive effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Growth and development of pups of all treated groups was markedly inferior to that of the controls. It’s considered that such a retardation of growth would result in a pup population which, if used for a long-term study, would show survival characteristics that would not be comparable to those of the controls.
It’s therefore concluded that none of the levels used in this study are suitable for use in an in utero derivation programme for long-term study. It’s considered that a suitable high dietary level for such a study design would be lower than 3000 ppm coumarin.

Executive summary:

Introduction:

The purpose of this study, performed at the Huntingdon Research Centre, England, was to determine a suitable high dietary level of coumarin, a food and cosmetic flavouring substance, for a long-term feeding study in rats following in utero exposure.

The high dietary level used in this study was based on findings by Griepentrog(Griepentrog, F., (1973) Toxicology, 1, 93-102)

This report contains all data generated during the study.

Results: Growth and development of pups of all treated groups was markedly inferior to that of the controls. It's considered that such a retardation of growth would result in a pup population which, if used for a long-term study, would show survival characteristics that would not be comparable to those of the controls.

It's therefore concluded that none of the levels used in this study are suitable for use in an in utero derivation programme for long-term study. It's considered that a suitable high dietary level for such a study design would be lower than 3000 ppm coumarin.