6,10-dimethylundeca-3,5,9-trien-2-one

Toxicity to reproduction

Administrative data

Endpoint:

one-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Recent study according to OECD Guideline 415 under GLP, with full report and all individual data

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Reference 2

Reference Type:

secondary source

Title:

No information

Author:

Beekhuizen MEW

Year:

2007

Bibliographic source:

OECD SIDS, Final 04/2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 415 [One-Generation Reproduction Toxicity Study (before 9 October 2017)]

GLP compliance:

yes

Remarks:

NOTOX BV

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

6,10-dimethylundeca-3,5,9-trien-2-one

EC Number:

205-457-1

EC Name:

6,10-dimethylundeca-3,5,9-trien-2-one

Cas Number:

141-10-6

Molecular formula:

C13H20O

IUPAC Name:

6,10-dimethylundeca-3,5,9-trien-2-one

Details on test material:

- Name of test material (as cited in study report): Pseudoionone
- Manufacturer: Teranol AG, Lalden
- Lot/batch No.: UU02033826,
- Analytical purity: 95.4% (area, GC).

Test animals

Species:

rat

Strain:

other: Wistar Crl: (WI) BR (outbred, SPF quality)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: males 5 - 6 weeks old; females 11 - 12 weeks old
- Identification: tattoo on the tail
- Housing: suspended stainless-steel cages, 4 animals per sex per cage, with males and females being kept in separate rooms. Mated females and males were housed individually in labelled polycarbonate cages containing sawdust (SAWI bedding, Jelu-Werk, Rosenberg, Germany) as bedding material. During the final stage of the pregnancy period, from day 16 post coitum, and during lactation, paper (Enviro-dri, BMI, Helmond, The Netherlands) was supplied to the dams for incorporation into the nest. The paper was replaced when soiled.
- Diet (e.g. ad libitum): ad libitum, standard pelleted rat diet (Altromin, code VRF1, Lage, Germany)
- Water (e.g. ad libitum): ad libitum, tap water
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 - 24
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12 / 12

Analyses for all batches of feed and quarter-yearly analyses of tap water are retained at NOTOX archives

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

maize oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
- Pseudoionone was formulated daily

VEHICLE
- Amount of vehicle (if gavage): 5 ml/kg bw

Details on mating procedure:

- M/F ratio per cage: 1/1 from same dose group
- Length of cohabitation: until vaginal plug was found; max. 3 weeks
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
- After 21 days of unsuccessful pairing pairs were separated.
- After successful mating each pregnant female was caged (how): individually

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Formulations were analytically confirmed to be stable for at least 4 hours at room temperature and to correspond to targeted concentrations.

Duration of treatment / exposure:

Exposure period: males: mean 106 (range 104-108) days;
females: mean 60 (range 36-65) days
Premating exposure period (males): 11 weeks
Premating exposure period (females): 2 weeks
Duration of test: 126 days

Frequency of treatment:

once daily

Doses / concentrations

Remarks:

Doses / Concentrations:
40, 120 and 360 mg/kg bw/d
Basis:
nominal conc.

No. of animals per sex per dose:

24

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: dose levels were based on a GLP 28-day subchronic toxicity study with the same dose levels that resulted in a NOEL of 50 mg/kg bw/d and a LOEL of 250 mg/kg bw/d with reversible effects (-> 7.5.1 Strobel1997.Repeated dose toxicity: oral rat 28d)

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily


BODY WEIGHT: Yes
- Time schedule for examinations: on the first day of exposure and weekly thereafter; Mated females were weighed on days 0, 7, 14 and 21 of gestation and during lactation on days 1, 4, 7, 14 and 21


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption of mated females was recorded on gestation days 0, 7, 14 and 21 and during lactation on days 1, 4, 7, 14 and 21


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes, but only subjective appraisal was maintained

REPRODUCTIVITY
- numbers of animals mated, mating date, confirmation of pregnancy and day of delivery were recorded

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter (4/sex/litter as nearly as possible); excess pups were killed and discarded.


PARAMETERS EXAMINED
The following parameters were examined in F1 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight (1, 4, 7, 14 and 21 of lactation), physical or behavioural abnormalities

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals, males were killed after confirmation of the pregancy of the female they had been mated with or after successful delivery of the respective dam.
- Maternal animals: All surviving animals killed at day 21 post partum or shortly thereafter


GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.


HISTOPATHOLOGY / ORGAN WEIGHTS
-The tissues indicated were prepared for microscopic examination and weighed:
cervix plus uterus, epididymides (both together), kidney, liver, ovaries, pituitary (weighed after 24 h fixation), prostate (weighed after 24 h fixation), seminal vesicles together with coagulating gland and fluids, spleen and testes.
-All organ and tissue samples as listed below were processed, embedded, microtomed at 2-4 µm and stained with haematoxylin and eosin: kidneys and liver from 10 randomly selected animals per sex from all treatment groups. All slides were examined by a professional histopathologist, abnormalities were described and included in the histopathology report. The histopathologist was asked to add an interpretation of the findings

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring was sacrificed at at day 21 post partum.
- These animals were subjected to postmortem examinations (macroscopic and/or microscopic examination) as follows: Main offspring found dead or killed before day 14 of lactation were sexed and externally examined if practically possible. Main offspring found dead or killed on or after day 14 of lactation were sexed and subjected to external examination of the thoracic and abdominal tissues and organs


GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.
- All abnormalities were recorded. If possible, defects or cause of death were evaluated.

Statistics:

For variables assumed to follow a normal distribution, the Dunnett test was applied; for other assumed distributions the Steel test was used. In those cases where variables could be dichotomised without loss of information, the exact Fisher test was applied. All tests were two-sided, significance was accepted at p < 0.05.

Results and discussion

Results: P0 (first parental generation)

Effect levels (P0)

Dose descriptor:

NOAEL

Effect level:

120 mg/kg bw/day

Sex:

male/female

Results: F1 generation

Effect levels (F1)

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

360 mg/kg bw/day

Sex:

male/female

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

Protocol deviations
13 protocol deviations are listed in the report. All 13 were
evaluated and considered not to have affected the integrity
of the study or of the results.

Dose preparations
A first analysis of formulations prepared on 17-Jun-2002
showed values for accuracy within the range of 86-131% for
pseudoionone peak 1 and of 84-126% for peak 2, which was
considered insufficient. Additional analyses were performed
and the one of the formulations prepared on 24-Jun-2002
showed 98-102% for peak 1 and 97-102% for peak 2. The
insufficient results were considered to originate from
pipetting errors of the volatile solvent (n-hexane) during
sample pretreatment for chemical analysis. Preparations of
the formulations, however, were performed according to the
accurate method and it was concluded that the animals
received the complete and correct exposure to the test
substance.
Analyses for homogeneity of the low- and high-dose
formulations prepared on 17-Jun-2002, 24-Jul-2002 and
29-Aug-2002 all showed values within the range of 94-109%
for peak 1 and of 84-115% for peak 2, which were considered
acceptable for this type of formulations. 
A stability analysis of the low- and high-dose formulations
from 17-Jun-2002 showed decreases over 7 days of 15% (peak
1) and and 11% (peak 2) for groups 40 mg/kg bd/d and of 15%
(peak 1) and 13% (peak 2) for group 360 mg/kg bw/d, which
was considered sufficient in view of the fact that
formulations were prepared daily.

Mortalities
There were 3 unscheduled deaths out of a total of 192 main
parental animals; all 3 animals were females. Two were
killed in extremis, one each in the 120 and the 360 mg/kg
bw/d groups after 38 respectively 43 days of treatment. The
other animal, also a female from the 360 mg/kg bw/d group,
died spontaneously on day 38. All three were found to have
severe delivery difficulties, with 17 foetuses in the birth
canal, 16 dead pups and three foetal resorptions, and 19
foetuses in the birth canal, respectively. These deaths were
considered incidental and very possibly caused by the big
litter sizes. Therefore, these deaths were considered not to
be related to the treatment with the test substance.

Clinical signs
Salivation was observed in all males and females of the
highest dose group. Incidental findings consisted of
alopecia, lethargy, clonic spasms, rales, salivation, scabs,
nodule at the tail, red staining of the right eye, broken
teeth, hunched posture, piloerection, pale appearance,
emaciation, dull eyes and dark eyes. No relationship was
established with treatment for these observations or they
were considered to be within the normal biological variation
for rats of this age and strain. Animal no. 40 of group 2
(40 mg/kg bw/d) showed several signs of stress (compulsive
biting, saltator spasms, tremor and muscle twitching) just
before or after dosing during four days of treatment.

Body weight
Body weights and body weight gain rates were unaffected by
treatment up to 360 mg/kg bw/d.

Food consumption
Statistically significant increases in relative food
consumption were observed in some of the 120 and 360 mg/kg
bw/d males. No explanation for this increase can be given,
however, this finding was not considered an adverse effect,
it was considered incidental in nature and not to be
toxicologically relevant.

Macroscopic examination
No treatment-related macroscopic findings were identified
but a number of findings that were considered incidental in
nature. These findings included pelvic dilation of the left,
right or both kidneys, testes reduced in size, flaccid
testes, enlarged testes, accentuated lobular pattern of the
liver, pale discolouration of the liver, alopecia at several
parts of the body, dark red discolouration of the
mediastinal cranial lymph nodes, isolated yellowish hard
nodule at the tail of the left epididymis, dark red hard
nodule at the left and right tips of the epididymides,
epididymides reduced in size, enlarged liver, reddish soft
nodule at the papillary process of the liver, soft nodule at
the papillary process of the liver, stomach and spleen grown
together with a soft nodule at the papillary process of the
liver, dark red discolouration of the left mandibular lymph
node. These findings are occasionally seen among rats used
in this type of study and, in the absence of correlated
microscopic histopathological findings, were not considered
of toxicological significance. Fluid in the uterus (in one
female of the control group, in three females of the 40
mg/kg bw/d group, in one female of the 120 group and in one
female of the 360 group) is related to a stage in the
oestrous cycle and is a normal finding.
In the 120 mg/kg bw/d group, one female that was killed in
extremis showed 17 foetuses in the birth canal. Of the 360
group, one female that was killed in extremis showed 3
foetal resorptions and 9 placentas in the left uterus horn
and the thoracic cavity containing milky-cloudy fluid; one
female from the 360 group that died spontaneously showed 19
foetuses in the birth canal and beginning autolysis.

Organ weights
Males and females of the 360 mg/kg bw/d group showed
statistically significant increased absolute and relative
liver and kidneys weight. Males of the 120 group showed
significantly increased liver weight:
----------------------------------------------------------
Dose group,      Bodyweight-related organ weights (%bw),
mg/kg bw/d       group mean values
                 -----------------------------------------
                 liver                kidney
                 -------------------- --------------------
                 males      females   males      females
----------------------------------------------------------
   0    mean      3.33       4.28      0.68       0.69
        SD        0.23       0.31      0.05       0.04
        n        24         24        24         24
----------------------------------------------------------
  40    mean      3.39       4.16      0.68       0.69
        SD        0.19       0.45      0.06       0.05
        n        24         22        24         22
----------------------------------------------------------
 120    mean      3.61**     4.45      0.71       0.70
        SD        0.20       0.25      0.07       0.05
        n        24         23        24         23
----------------------------------------------------------
 360    mean      4.13**     4.75**    0.77**     0.73*
        SD        0.29       0.29      0.07       0.06
        n        24         22        24         22
----------------------------------------------------------
*/**: Dunnett's test on pooled variance, significant at 5%
(*) or 1% (**) level.
----------------------------------------------------------
In the absence of histopathological changes, both effects
were considered not to be toxicologically relevant but
rather manifestations of physiological adaptation to
additional metabolic and excretionary loads. 
Males of the 40 group showed statistically significantly
reduced seminal vesicles weight. In the absence of a
dose-response relationship, this finding was considered to
be caused by chance and not to be related to treatment.
Microscopic examination
There were no treatment-related findings. No
histopathological changes were found to correlate with the
observed increase in liver and kidney weights.

Reproduction
Reproduction parameters were unaffected by treatment up to
360 mg/kg bw/d. In the 40 group, one female did not mate and
one female was non-pregnant. In the 120 group, one female
showed delivery difficulties, and in the 360 group, two
females showed delivery difficulties. Mating performance,
duration of gestation and fertility parameters including
number of pups at birth were similar for the control and
treated groups.