2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: well documented, according to OECD guideline and GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

444-860-9

EC Name:

-

Cas Number:

474510-57-1

Molecular formula:

C21 H24 O4

IUPAC Name:

2-hydroxy-1-(4-{[4-(2-hydroxy-2-methylpropanoyl)phenyl]methyl}phenyl)-2-methylpropan-1-one

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Harlan Laboratories, B.V. Kreuzelweg 53 5961 NM Horst / Netherlands
- Age at study initiation: 11 weeks
- Weight at study initiation: Males: 291 to 371 g, Females: 182 to 213 g
- Housing: singly
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 7d
- Fasting: 16h before administration

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 30-70
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
-The dose formulations were prepared weekly
- Homogeneity of the test item in the vehicle was maintained during the daily administration period using a magnetic stirrer.

VEHICLE
- Justification for use and choice of vehicle (if other than water): As used in previous dose range-finding study

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The samples were analyzed following an analytical procedure provided by the Sponsor and
adapted at Harlan Laboratories. The test item was used as the analytical standard. Analyzed
samples were not discarded without written consent from the study director.
Duplicates were taken of all samples and were stored at Harlan Laboratories Ltd., Füllinsdorf /
Switzerland. The samples were not discarded without written consent from the study director.

Duration of treatment / exposure:

Males: 4 weeks
Females: Approximately 7 weeks

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
10, 30, 90 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The dose levels were selected based on a previous dose range-finding toxicity study in Han Wistar rats

Positive control:

no

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: daily

HAEMATOLOGY: Yes
- Time schedule for collection of blood: on the day of the scheduled necropsy from 5 males from each group, blood samples from 5 lactating females from each group were obtained on day 5 post partum
- Anaesthetic used for blood collection: Yes, isoflurane
- Animals fasted: Yes, 18h
- How many animals: 5 per sex and group
- Parameters checked in table [1] were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: on the day of the scheduled necropsy from 5 males from each group, blood samples from 5 lactating females from each group were obtained on day 5 post partum
- Animals fasted: Yes, 18h
- How many animals: 5 per sex and group
- Parameters checked in table [2] were examined.

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: one time during the study
- Dose groups that were examined: 5 animals per sex and group
- Battery of functions tested: cage side observations, hand-held observations, open field observations, reflexes, hind / fore limb strength

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (see table)
HISTOPATHOLOGY: Yes (see table)

Statistics:

The Dunnett-test (many to one t-test) based on a pooled variance
estimate was applied if the variables could be assumed to follow a normal distribution
for the comparison of the treated groups and the control groups for each sex.
• The Steel-test (many-one rank test) was applied instead of the
Dunnett-test when the data could not be assumed to follow a normal distribution.
• Fisher's exact-test was applied if the variables could be
dichotomized without loss of information.

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

effects observed, treatment-related

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
At 90 mg/kg body weight/day, one male was killed for ethical reason, relationship to the treatment could not be excluded.
Test item-related clinical signs were observed of males and females receiving 90 mg/kg body weight/day. Hunched posture, ruffled fur and discoloured feces were seen in the pre-pairing and pairing period in males and in the pre-pairing, through pairing and gestation period in females.

BODY WEIGHT AND WEIGHT GAIN
The mean body weight gain of males receiving 90 mg/kg body weight/day was lower from day 5 of pre-pairing period when compared to controls and it was statistically significantly reduced between days 8 and 14. In correlation with the low food consumption this was considered to be a test item-related effect.

FOOD EFFICIENCY
The mean food consumption of males receiving 90 mg/kg body weight/day was statistically significantly lower on the second week of pre-pairing period, and for females during the whole pre-pairing period. This was considered to be a test item-related effect.

NEUROBEHAVIOUR
A slightly lower locomotor activity of the high dose group was seen, thus a treatment-related effect can not be excluded. For females at the dose level of 90 mg/kg body weight/day, total level of locomotor activity was statistically significantly reduced.

ORGAN WEIGHTS
Absolute and relative mean liver weights (both relative to body weight and relative to brain weight) were statistically increased in males and females of group 4 (90 mg/kg body weight/day). Additionally, absolute and relative mean thymus weights were statistically significantly decreased in females of the 90 mg/kg body weight/day group.

GROSS PATHOLOGY
Treatment-related adverse local irritative effects in the stomach were observed in all test item-treated groups at incidences of 1, 2 and 2 animals at the dose levels 10, 30 and 90 mg/kg body weight/day, respectively.
The reduced size in thymus in females, occurring in increased incidences, at ≥ 10 mg/kg body weight/day correlated histopathologically with athropy and reduced absolute and relative thymus weights only at the high dose levels. Although this is considered to be most likely to be stress related a test item-relationship cannot be excluded at the 90 mg/kg body weight/day dose level.

HISTOPATHOLOGY: NON-NEOPLASTIC
Treatment-related diffuse liver cell hypertrophy at 90 mg/kg body weight/day was considered to be adaptive. This hypertrophy was associated with follicular cell hypertrophy in thyroid glands in some males and females at 90 mg/kg body weight/day. Most probably the enhanced liver cell metabolism resulted in an acceleration of thyroid hormone breakdown with consequent thyroid follicular cell hypertrophy. This finding is commonly seen in rats after being exposed to xenobiotics.

HISTORICAL CONTROL DATA (if applicable)
historical dat (up to 23 studies) for FOB, breeding, organ weights, organ/BW and organ/brain ratios

Effect levels

Dose descriptor:

NOAEL

Effect level:

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

Sex:

male/female

Target system / organ toxicity

Critical effects observed:

not specified