Reaction mass of 3-(4-hydroxy-4-methylpentyl)cyclohex-3-ene-1-carbaldehyde and 4-(4-hydroxy-4-methylpentyl)cyclohex-3-ene-1-carbaldehyde

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 Mar 2005 to 11 Jan 2006

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 415 [One-Generation Reproduction Toxicity Study]

Version / remarks:

Before 9 October 2017

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 3-(4-hydroxy-4-methylpentyl)cyclohex-3-ene-1-carbaldehyde and 4-(4-hydroxy-4-methylpentyl)cyclohex-3-enecarbaldehyde

EC Number:

915-617-9

Molecular formula:

C13H22O2

IUPAC Name:

Reaction mass of 3-(4-hydroxy-4-methylpentyl)cyclohex-3-ene-1-carbaldehyde and 4-(4-hydroxy-4-methylpentyl)cyclohex-3-enecarbaldehyde

Test material form:

liquid

Test animals

Species:

rat

Strain:

other: Crl:CD (SD)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- See section on fertility

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on exposure:

- M/F ratio per cage 1 :1
- Length of cohabitation: a maximum of 21 days
- Proof of pregnancy vaginal plug and/or sperm in vaginal smear referred as day 1 of pregnancy

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The concentration of the test substance in arachis oil was determined by gas chromatography using an external standard technique.

Details on mating procedure:

76 days pre-mating, maximal 21 days mating. Males were killed and examined upon successful mating, females and offspring were killed and examined on day 21 post-partum. No pregnant females were killed and examined after 25 days post coitum.

Duration of treatment / exposure:

For males 83 days and for females 140 days

Frequency of treatment:

Daily (except for females during littering/parturation)

Duration of test:

For males this was 83 days and for females 140 days

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

25 mg/kg bw/day (actual dose received)

Remarks:

Group 2

Doses / concentrations 2

Dose / conc.:

100 mg/kg bw/day (actual dose received)

Remarks:

Group 3

Doses / concentrations 3

Dose / conc.:

500 mg/kg bw/day (actual dose received)

Remarks:

Group 4

No. of animals per sex per dose:

24

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection based on results of a 14-day dose-range finding study
- Rationale for animal assignment (if not random): the animals were allocated to dose groups using a randomisation

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
-Time schedule the animals for overt signs of toxicity, ill-health and behavioural change immediately before and after the dosing, and 1 - 5 hours post dosing during the working week.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: immediately before and after the dosing, and 1-5 hours post dosing during the working week.

BODY WEIGHT:
- On day 0. Males were weighed weekly. Females were weighed weekly during maturation and daily during mating. One mating was evident body weights were then recorded on Day 1, 4, 7, 14 and 21 of post coitum and post-partum

FOOD CONSUMPTION: Yes
- Time schedule: during the maturation period, weekly food consumption was recorded for each cage of adults. For females showing evidence of mating, food consumption was recorded for the periods covering Days 1 - 7, 7 - 14 and 14 - 21 post coitum. For females with live litters food consumption was recorded for the period covering Days 1 - 7, 7 - 14 and 14 - 21 post-partum

WATER CONSUMPTION: Yes
- Time schedule: water intake was observed daily by visual inspection of the water bottles for any overt change

POST-MORTEM EXAMINATIONS: Yes

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: No
- Number of late resorptions: No

Fetal examinations:

- External examinations: Yes, all per litter
- Soft tissue examinations: No
- Skeletal examinations: Yes, all per litter
- All live offspring were observed for the detachment and unfolding of the pinna, incisor eruption, and eyelid separation and assessed for reflexological response to stimuli by assessing surface righting reflex on Day 1 post-partum and air righting reflex on Day 17 post-partum. Pupillary reflex and auditory startle response were performed on Day 21 post-partum.

Statistics:

The data were processed for dose response relationships by linear regression analysis, followed by one way analysis of variance (ANOVA) incorporating Levene's test for homogeneity of variance. Where variances were shown to be homogenous, pairwise comparisons were conducted using Dunnett's test. Where Levene's test showed unequal variances the data were analysed using non-parametric methods: Kruskal-Wallis ANOVA and Mann-Whitney 'U' test.

Indices:

Relevant for developmental toxicity
- Live birth and viability indices, sex ratio and pre- and post-implantation loss.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Maternal toxicity was seen at 500 mg/kg bw considering variation in body weight.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption of the high dose was increased at 500 mg/kg bw during gestatin and during lactation they showed decrease in food consumption (-21 %).

Maternal developmental toxicity

Changes in pregnancy duration:

effects observed, treatment-related

Description (incidence and severity):

Maternal toxicity was seen at 500 mg/kg bw considering variation in viability of the gestation length. At 500 mg/kg bw the gestation lenght was increased and less so at 100 mg/kg bw. The NOAEL is based on this increase in gestation length at 100 mg/kg bw. The effect on which the NOAEL was based is the increased gestation length at 100 mg/kg bw.

Other effects:

effects observed, treatment-related

Description (incidence and severity):

Maternal toxicity was seen at 500 mg/kg bw considering variation in viability of offspring.

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Remarks:

Maternal toxicity

Effect level:

25 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Maternal abnormalities

Key result

Abnormalities:

no effects observed

Results (fetuses)

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

The body weight of the offspring at 500 mg/kg bw was reduced and less so at 100 mg/kg at the start of the Day 1 of lactation but at the end of lactation period no statistical differences were found.

Visceral malformations:

effects observed, treatment-related

Description (incidence and severity):

At 500 mg/kg bw pinna the onset and completion of the pinna unfolding was delayed with ca 2 days at this dose also the incisor eruption completion was delayed with one day. At 100 mg/kg bw the pinna unfolding was delayed ca 1 day compared to the controls

Other effects:

effects observed, treatment-related

Description (incidence and severity):

Skin sloughing was seen from Day 5 of lactation at 500 and 100 mg/kg bw, which is a rare effect. Therefore additional developmental toxicity testing was done.

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Remarks:

Developmental toxicity

Effect level:

25 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: delay of development and skin sloughing

Remarks on result:

other:

Remarks:

Life birth index was significantly lower (15%) at 500 mg/kg bw and also minimally at 100 mg/kg bw. Of the high dose females that gave birth to live litters 6 females has a total litter loss, predominantly between birth and Day 1. The viability of the remaining offspring was similar to controls. Females treated with 100 mg/kg bw showed a slight reduction in the number of implantations and reduced litter size throughout lactation, compared to the control. This latter effect was significant on Day 1 and 4 but finally the survival indexes were essentially similar to control and these differences were considered to reflect normal biological variation rather than any adverse effect on post-natal survival. At 500 mg/kg bw the onset (+2.1 days) and completion (+2.8 days) of pinna unfolding was evident in the 500 mg/kg bw offspring with a reduction in the number of offspring passing surface righting, air righting and pupil reflex. Some of these effects were also evident at 100 mg/kg bw. Skin sloughing was seen in offspring at 500 and 100 mg/kg bw during starting at Day 5 of lactation. At 25 mg/kg bw only single incidences in pups showed the skin sloughing effects and these effects were reversible at those dose and therefore the NOAEL for developmental toxicity is set at this 25 mg/kg bw.

Fetal abnormalities

Key result

Abnormalities:

effects observed, treatment-related

Localisation:

other: see description

Description (incidence and severity):

The body weight of the offspring at 500 mg/kg bw was reduced and less so at 100 mg/kg at the start of the Day 1 of lactation but at the end of lactation period no statistical differences were found. At 500 mg/kg bw pinna the onset and completion of the pinna unfolding was delayed with ca 2 days at this dose also the incisor eruption completion was delayed with one day. At 100 mg/kg bw the pinna unfolding was delayed ca 1 day compared to the controls. Air righing was affected at the 500 mg/kg bw with 18 %. Skin sloughing was seen from Day 5 of lactation at 500 and 100 mg/kg bw, which is a rare effect. Therefore additional developmental toxicity testing was done.

Overall developmental toxicity

Key result

Developmental effects observed:

yes

Lowest effective dose / conc.:

100 mg/kg bw/day (actual dose received)

Treatment related:

yes

Relation to maternal toxicity:

developmental effects as a secondary non-specific consequence of maternal toxicity effects

Dose response relationship:

yes

Relevant for humans:

no

Applicant's summary and conclusion

Conclusions:

The NOAEL for developmental toxicity is set at 25 mg/kg bw based on delay of development and on skin sloughing at higher doses. At these higher doses also maternal toxicity was seen and therefore the developmental toxicity effects can be related to maternal toxicity.

Executive summary:

 In a one-generation (OECD TG 415, in compliance with GLP) doses of 0, 25, 100 and 500 mg/kg bw have been administered to male and female rats. In the parent animals clinical observation, body weight, food consumption, water consumption have been measured. Considering reproductive toxicity, mating, pregnancy and parturition, litter data and the physical development of the pups has been investigated. Pathology has been performed considering epididymides, ovaries, pituitary gland and prostate. And these organs are also investigated histopathologically. Also other organs have been investigated macroscopically. Fertility indices have been calculated as well as gestation length and parturition indices. Lactation data such as live birth and viability indexes, sex ratio, implantation losses were calculated.

Life birth index was significantly lower (15 %) at 500 mg/kg bw and also minimally at 100 mg/kg bw. Of the high dose females that gave birth to live litters 6 females has a total litter loss, predominantly between birth and Day 1. The remaining offspring was similar to controls. Females treated with 100 mg/kg bw showed a slight reduction in the number of implantations and reduced litter size throughout lactation, compared to the control. This was significant on Day 1 and 4 but finally the survival indexes were essentially similar to control and these differences were considered to reflect normal biological variation rather than any adverse effect on post-natal survival. At 500 mg/kg bw the onset (+2.1 days) and completion (+2.8 days) of pinna unfolding was evident in the 500 mg/kg bw offspring with a reduction in the number of offspring passing surface righting, air righting and pupil reflex. Some of these effects were also evident at 100 mg/kg bw. Skin sloughing was seen in offspring at 500 and 100 mg/kg bw during starting at Day 5 of lactation. The incidence being particularly pronounced at the 500 mg/kg bw. At 25 mg/kg bw only few offspring showed the skin sloughing effects and the effect was reversible at this dose and therefore the NOAEL is set at this dose. Maternal toxicity was seen at 500 mg/kg bw considering high variability in body weight. Food consumption of the high dose was increased at 500 mg/kg bw during gestation and during lactation they showed decrease in food consumption (-21 %). At 500 mg/kg bw the gestation length was increased and less so at 100 mg/kg bw. The NOAEL is based on this increase in gestation length at 100 mg/kg bw.