Docosanoic acid, ester with 1,2,3-propanetriol

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - Guideline study. According to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

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

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Docosanoic acid

EC Number:

204-010-8

EC Name:

Docosanoic acid

Cas Number:

112-85-6

Molecular formula:

C22H44O2

IUPAC Name:

docosanoic acid

Details on test material:

- Name of test material (as cited in study report): docosanoic acid
- Physical state: white powder
- Analytical purity: 85.9%
- Lot/batch No.: 60805X
- Impurities (identity and concentrations): C14-C20 fatty acids: 10.9%, C24 fatty acids: 2.3%
- Storage condition of test material: at room temperature in the dark

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 Japan, Hino, Tokyo, Japan
- Age at study initiation: 8 weeks
- Weight at study initiation: 312.1 - 363.7 g (males); 205.3 - 230.8 g (females)
- Housing: metal wire floor cages
- Diet (ad libitum): CE-2, CLEA Japan
- Water (ad libitum): tap water
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 ± 1
- Humidity (%): 50 - 65
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: dosing solutions were prepared more frequently than once a week; aliquots of each concentration were kept refrigerated in airtight conditions.

VEHICLE
- Justification for use and choice of vehicle (if other than water): due to the insolubility in water, corn oil was selected as appropriate vehicle
- Amount of vehicle (if gavage): 5 mL/kg bw
- Lot/batch no. (if required): V6H2050

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

- males: 42 days
- females: 14 days prior to mating to day 3 of lactation

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
100, 300, 1000 mg/kg bw/d
Basis:
actual ingested

No. of animals per sex per dose:

13

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: based on a preliminary 14 day-repeated dose toxicity study, where no signs of toxicity were found

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: at least once a day

BODY WEIGHT: Yes
- Time schedule for examinations: males: day 1, 8, 15, 22, 29, 36 and 42; females: premating day 1, 8 and 15; pregnancy day 0, 7, 14 and 20; lactation day 0 and 4

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes

HAEMATOLOGY: Yes (males only)
- Time schedule for collection of blood: prior to autopsy
- Anaesthetic used for blood collection: Yes (identity): pentobarbital sodium
- Animals fasted: 18 - 24 h before sacrifice
- How many animals: all surviving animals
- Parameters checked: red blood cell count (RBC), white blood cell count (WBC), haemoglobin content (Hb), mean corpuscular volume (MCV), haematocrit (Ht), mean corpuscular haemoglobin content (MCH), mean corpuscular haemoglobin concentration (MCHC)

CLINICAL CHEMISTRY: Yes (males only)
- Animals fasted: 18 - 24 h before sacrifice
- How many animals: all surviving animals
- Parameters checked: total protein, albumin, total cholesterol concentration, glucose, urea nitrogen, creatinine, alkaline phosphatase activity (ALP), glutamate-oxalacetate-transaminase (GOT), glutamate pyruvate transaminase (GPT), gamma-glutamyl transpeptidase (γ-GTP), triglyceride concentration, inorganic phosphorus, total bilirubin, calcium, sodium, potassium, chlorine, albumin/globulin ratio (A/G ratio)

URINALYSIS: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
Organ weights:
male: heart, liver, kidneys, thymus, testes, epididymides
female: heart, liver, kidneys, thymus

HISTOPATHOLOGY: Yes (control and 1000 mg/kg bw /day group):
male: heart, liver, spleen, kidneys, adrenal, testes, epididymis, brain, thymus, bladder
female: brain, liver, spleen, thymus, kidneys, adrenals, bladder, heart, ovaries

Statistics:

Yates-test, Mann-Whitney-U-test, Fisher exact-test, Bartlett-test, Dunnett-test, Scheffe-test, Kruskal-Wallis-test

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

100 mg/kg bw/d: increased body weight of males (non-adverse)

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

100 mg/kg bw/day (females): significant reduced food consumption during lactation (non-adverse); 100 mg/kg bw/day (males): increased food consumption

Food efficiency:

no effects observed

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

300 and 1000 mg/kg bw/d: significant decrease of mean corpuscular haemoglobin concentration in males (non-adverse)

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

all dose groups: sporadic effects on glucose, total protein, calcium, ALP (non-adverse)

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

100 mg/kg bw/d: significant liver weight increase in males and signficant decrease in kidney weights in females (non-adervse)

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

all dose groups: sporadic effects on adrenal gland, thyroids, thymus, lung, liver, kidney and spleen in males and females (non-adverse)

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

1000 mg/kg bw/d: sporadic findings in brain, heart, liver, spleen, kidney, adrenals, thymus and testes in males and females (non-adverse)

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
No mortality and no clinical signs were observed.

BODY WEIGHT AND WEIGHT GAIN
Body weight gain in male animals of the 100 mg/kg bw/day group was higher when compared to the 300 and 1000 mg/kg bw/day dose groups and to the control group (10-33%) over the whole treatment period. Since this effect showed no dose-relation and no other effects of toxicity were observed in this dose group, it was regarded as non-adverse.

FOOD CONSUMPTION
Food consumption of males of the 100 mg/kg bw dose group was about 4-10% increased when compared to controls. A significant decreased food consumption was observed in females of the same dose group during lactation. Since this effect was not dose-related, it was regarded to be not treatment related.

HAEMATOLOGY
A significant decrease of 3% of mean corpuscular haemoglobin concentration in males of the 300 and 1000 mg/kg bw/day dose groups was observed after 42 days of treatment. Since this effect showed no clear dose-relation, it was regarded as non-adverse.

CLINICAL CHEMISTRY
A significant decrease of the glucose level (22%) in the 1000 mg/kg bw/day dose group males was observed. Additionally a decrease in total protein (4%) and calcium (5%) in the 300 mg/kg bw/day dose group males and in ALP (16-18%) in males of all dose groups was found. As these effects occured sporadically and showed no dose-relationship, they were regarded as non-adverse.

ORGAN WEIGHTS
In the 100 mg/kg bw/day dose group, a significant liver weight increase (12% (absolute weight), 5% (relative weight)) in males and a signficant decrease in kidney weights in females (8% (absolute weight), 3% (non-adervse)) was observed. As there was no dose relationship and no effects were observed at histopathology, they were regarded as non-adverse.

GROSS PATHOLOGY
In males of the 100 mg/kg bw/dose group, diminishment of thymus (1 animal), accessory spleen (1 animal) and liver changes (yellowish colouring (2 animals), pale spot (1 animal), accentuation of lobular pattern (1 animals)) were observed. In males of the 300 mg/kg bw/dose group, enlargment of thyroid (1 animal), pale lung (1 animal), diminishment of thymus (1 animal) and liver changes ((pale area (2 animals), pale spot (1 animal)) were observed. In males of the 1000 mg/kg bw/dose group, diminishment of thymus (1 animal), small and enlarged thymus (1 animal each), pale lung (1 animal) and yellowish colouring of the liver (2 animals) was observed.
Focal constriction of the spleen was observed in two high-dose group females and adrenal enlargement in one female animal of the 100 mg/kg bw/day dose group. Since the observed effects in male and female animals were found without any dose-relationship and only in few animals, they were regarded as not treatment related.

HISTOPATHOLOGY: NON-NEOPLASTIC
Mycardial degeneration, liver fatty change, changes in spleen and kidney were found to the same extent in few male animals of the highest dose group as compared to males of the control group. One male animal of the highest dose group showed slight fibrosis of the adrenal gland and another one very slight changes of the testes.
The only change differing from controls in females of the high dose group was a thalamus mineralisation in the brain found in one animal. Thus, the effects were regarded as not treatment related.

Effect levels

Dose descriptor:

NOAEL

Remarks:

(repeated dose toxicity)

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no substance-related findings were observed

Target system / organ toxicity

Critical effects observed:

not specified