[No public or meaningful name is available]

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

reproductive toxicity, other

Remarks:

sub-chronic oral repated dose toxicity study with additional information on reproductive toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Report does not contain all study details. Female fertility data are identical in rats and mice, indicating a transcription error.

Reason / purpose for cross-reference:

reference to same study

Principles of method if other than guideline:

Within a 90 day oral feeding study performed equivalent to OECD guideline 408 with Castor oil, male and female fertility parameters were analyzed in rats and mice. No matings were performed.

GLP compliance:

yes

Limit test:

no

Species:

other: rats and mice

Strain:

other: F344/N and B6C3F1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Simonsen Laboratories (Gilroy, CA, USA)
- Age at study initiation: 6 weeks
- Weight at study initiation: male rats: 126 - 132 g; female rats: 107- 110 g, male mice: 22.6 - 23.0 g, female mice: 17.2 - 17.7 g
- Fasting period before study:
- Housing: rats: 5 per cage, mice individually in Polycarbonate cages lined with heat-treated hardwood chips, covered with polyester filter sheets.
- Diet: Control feed (NIH 07) or diet formulations of castor oil were available ad libitum; feeders were changed twice per week throughout the study.
- Water: automatic watering system, ad libitum
- Acclimation period: 14 days


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68-76
- Humidity (%): 42-72
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Formulated diets were prepared by blending the appropriate amount of castor oil with a small quantity of feed to prepare a premix. The premix then was layered between the required amount of feed in a twin-shell blender and blended for 15 minutes to achieve a uniform mix. The homogeneity of castor oil in feed at 10% (100 mg/g) was determined by gravimetric analysis, and blends at 0.5% (5 mg/g) were determined by HPLC analysis. These concentrations of chemical in feed were found to be homogeneously distributed by this mixing procedure. The stability of the 0.5% dose level was determined using HPLC; it was found to be stable for at least 21 days when stored in the dark at 5°C and for 3 days when stored open to air and light in a rodent cage. During the studies, formulated diets were stored for no longer than 3 weeks at 5°C; feed hoppers in the animal cages were changed twice weekly.

Details on mating procedure:

no matings performed

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The results of the analyses for all dose mixtures given to the animals ranged from 97% to 106% of the target concentrations.

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

continuos treatment via the diet

Dose / conc.:

2.5 other: % (w/w) nominal concentration in the diet

Remarks:

corresponding to 1583 and 1569 mg/kg bw/day in male and female rats and 3800 and 5009 mg/kg bw/day in male and female mice, respectively (actual ingested concentration)

Dose / conc.:

5 other: % (w/w) nominal concentration in the diet

Remarks:

corresponding to 3067 and 3045 mg/kg bw/day in male and female rats and 7823 and 9627 mg/kg bw/day in male and female mice, respectively (actual ingested concentration)

Dose / conc.:

10 other: % (w/w) nominal concentration in the diet

Remarks:

corresponding to 5835 and 5725 mg/kg bw/day in male and female rats and 15017 and 16786 mg/kg bw/day in male and female mice, respectively (actual ingested concentration)

No. of animals per sex per dose:

10

Control animals:

yes, plain diet

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS/ CLINICAL OBSERVATIONS: Yes
- Time schedule: twice a day

BODY WEIGHT: Yes
- Time schedule for examinations: initially and 1 x wk thereafter.


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

Oestrous cyclicity (parental animals):

Proestrus, Estrous, Metestrous, Diestrous, Cycle Length (days)

Sperm parameters (parental animals):

Caudal weight, epididymal weight, testis weight, Sperm countig testis, Sperm motility (%)

Litter observations:

not performed

Postmortem examinations (parental animals):

Complete histopathology examinations were conducted on all rats and mice from the control and 10% dose groups. Livers were examined from male rats in all other dose groups; histologic sections of gross lesions were examined from all rats. Organ weights were determined to the nearest milligram for the liver, right kidney, right testicle, heart, thymus, and lungs. All tissues were preserved in 10% neutral buffered formalin.

The following tissues were routinely processed for preparation of histologic sections and microscopic examination: adrenal glands, brain, cecum, colon, duodenum, epididymis/seminal vesicles/prostate/testes or ovaries/uterus, esophagus, eyes (if grossly abnormal), femur (including marrow), heart, ileum, jejunum, kidneys, liver, lungs and mainstem bronchi, mammary gland, mandibular and mesenteric lymph nodes, nasal cavity and turbinates, pancreas, parathyroid glands, pituitary gland, preputial or clitoral glands, rectum, salivary glands, skin, spinal cord and sciatic nerve (if neurologic signs present), spleen, forestomach and glandular stomach, thymus, thyroid gland, trachea, urinary bladder, zymbal glands, and all gross lesions and tissue masses including regional lymph nodes. A complete histopathologic examination was conducted on all rats and mice from the control and 10% dose groups. Liver was examined from male rats in all other dose groups, and histologic sections of gross lesions were examined from all rats.

Postmortem examinations (offspring):

not performed

Statistics:

Dunn's test; Shirley's test.

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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):

No adverse biologically significant effects in rats (for details please refer to section 7.5.1 oral repeated dose toxicity); no effects observed in mice.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

No adverse biologically significant effects in rats (for details please refer to section 7.5.1 oral repeated dose toxicity); no effects observed in mice.

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

not examined

CLINICAL SIGNS AND MORTALITY
No effects

BODY WEIGHT AND WEIGHT GAIN
Group mean body weights of rats receiving diets containing castor oil did not differ significantly from controls. Mean body weights of exposed female rats were slightly lower than the mean body weights of controls but the differences were not dose-related.
Mean body weights of exposed male mice generally were lower than controls, while mean body weights of exposed females generally were higher. There were no obvious indications that these differences were related to dietary concentrations of castor oil, except that mean body weights of male mice receiving the 10% castor oil diet were consistently lower than those of control mice from week 3 through the end of the study.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No significant differences in average food consumption among each sex were observed, although food consumption of male and female rats receiving diets containing 10% castor oil was slightly lower than that of controls. Similarly, food consumption by female mice receiving diets containing 10% castor oil was slightly lower than controls.

ORGAN WEIGHTS
In male rats, there was a slight decrease in epididymal weight (6-7%) which occurred in the middle- and high-dose groups, but this was not dose-related. There were no effects on any other male rat reproductive endpoint, or on any female rat reproductive endpoint. Although there was some variation in epididymal weights, their small magnitude and the absence of changes in other endpoints suggested that there was little or no evidence of any reproductive toxicity associated with castor oil exposure. Histopathologic examination revealed an absence of compound-related lesions in any organ or tissue of rats exposed to castor oil in the diet.

Castor oil exposure produced no adverse effects on any male (testes weight, epididymal sperm motility, density, or testicular spermatid head count) or female (estrual cycle length, or time spent in each phase of the cycle) reproductive parameter among mice. The low value for sperm motility
in control mice was attributed to poor preparative technique.

Key result

Dose descriptor:

NOAEL

Remarks:

parental fertility rats

Effect level:

5 000 mg/kg bw/day (actual dose received)

Based on:

other: calculated test material intake based on food consumption and body weight

Sex:

male/female

Basis for effect level:

other: for rats based on oestrus stage and cycle length and sperm characterization.

Key result

Dose descriptor:

NOAEL

Remarks:

parental fertility mice

Effect level:

15 000 mg/kg bw/day (actual dose received)

Based on:

other: calculated test material intake based on food consumption and body weight

Sex:

male/female

Basis for effect level:

other: for mice based on oestrus stage and cycle length and sperm characterization.

Key result

Critical effects observed:

no

Clinical signs:

not examined

Dermal irritation (if dermal study):

not examined

Mortality / viability:

not examined

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Anogenital distance (AGD):

not examined

Nipple retention in male pups:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

not examined

Table 1: Reproductive System Data for F344/N Rats in the 13-Week Feed Studies

of Castor Oil

 

	Percent in Feed
	0	2.5	5	10
Male^a
Left caudal weight (mg)	151	153	145	153
Left epididymal weight (mg)	502	498	464*	476
Left testis (mg)	1539	1550	1463	1492
Sperm count (x10^6)/g testis	72.8	65.9	71.7	77.5
Sperm motility (%)	73.6	65.9	72.1	69.8
Female^b
Estrous stage (%)
Proestrus	12.5	14.2	15.8	16.7
Estrous	28.3	32.5	25.8	25.8
Metestrous	18.3	19.2	18.3	19.2
Diestrous	40.8	34.2	39.2	38.3
Not clear or no cells observed	0.0	0.0	0.8	0.0
Cycle Length (days)	5.0	5.1	5.2	5.1

^aMean for groups of 10 animals; no significant difference vs. the controls by Dunn's test

^bMean for groups of 10 animals unless otherwise specified

* Significantly different from control groups by Shirley's test ; p < 0.05.

 

Table 2: Reproductive System Data for B6C3F1 Mice in the 13-Week Feed Studies

of Castor Oil

 

	Percent in Feed
	0	2.5	5	10
Male^a
Left caudal weight (mg)	15	13	16	16
Left epididymal weight (mg)	45	46	46	44
Left testis (mg)	121	120	121	119
Sperm count (x106)/g testis	179.2	162.4	170.1	158.3
Sperm motility (%)	39.2	53.7	45.4	52.2
Female^b
Estrous stage (%)
Proestrus	12.5	14.2	15.8	16.7
Estrous	28.3	32.5	25.8	25.8
Metestrous	18.3	19.2	18.3	19.2
Diestrous	40.8	34.2	39.2	38.3
Not clear or no cells observed	0.0	0.0	0.8	0.0
Cycle Length (days)	5.0	5.1	5.2	5.1

^aMean for groups of 10 animals; no significant difference vs. the controls by Dunn's test

^bMean for groups of 10 animals unless otherwise specified

 

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

no ophthalmoscopy, no neurobehavioral examinations

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Castor oil

EC Number:

232-293-8

EC Name:

Castor oil

Cas Number:

8001-79-4

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Simonsen Laboratories, Gilroy, CA, USA
- Age at study initiation: 6 weeks
- Weight at study initiation: 126 - 132 g (males), 107- 110 g (females)
- Housing: rats: 5 per cage
- Diet (Control feed (NIH 07) or diet formulations of castor oil): ad libitum; feeders were changed twice per week throughout the study.
- Water (automatic watering system): ad libitum
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68-76
- Humidity (%): 42 - 72
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
Formulated diets were prepared by blending the appropriate amount of castor oil with a small quantity of feed to prepare a premix. The premix then was layered between the required amount of feed in a twin-shell blender and blended for 15 minutes to achieve a uniform mix. The homogeneity of castor oil in feed at 10% (100 mg/g) was determined by gravimetric analysis, and blends at 0.5% (5 mg/g) were determined by HPLC analysis. These concentrations of chemical in feed were found to be homogeneously distributed by this mixing procedure. The stability of the 0.5% dose level was determined using HPLC; it was found to be stable for at least 21 days when stored in the dark at 5°C and for 3 days when stored open to air and light in a rodent cage. During the studies, formulated diets were stored for no longer than 3 weeks at 5°C; feed hoppers in the animal cages were changed twice weekly.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The results of the analyses for all dose mixtures given to the animals ranged from 97% to 106% of the target concentrations.

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

continuously via the diet

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0.62 other: % (w/w) nominal concentration in the diet

Remarks:

corresponding to 404 mg/kg bw/day in males and 401 mg/kg bw/day in females (actual dose ingested)

Doses / concentrations 2

Dose / conc.:

1.25 other: % (w/w) nominal concentration in the diet

Remarks:

corresponding to 809 mg/kg bw/day in males and 797 mg/kg bw/day in females (actual dose ingested)

Doses / concentrations 3

Dose / conc.:

2.5 other: % (w/w) nominal concentration in the diet

Remarks:

corresponding to 1583 mg/kg bw/day in males and 1569 mg/kg bw/day in females (actual dose ingested)

Doses / concentrations 4

Dose / conc.:

5 other: % (w/w) nominal concentration in the diet

Remarks:

corresponding to 3067 mg/kg bw/day in males and 3045 mg/kg bw/day in females (actual dose ingested)

Doses / concentrations 5

Dose / conc.:

10 other: % (w/w) nominal concentration in the diet

Remarks:

corresponding to 5835 mg/kg bw/day in males and 5725 mg/kg bw/day in females (actual dose ingested)

No. of animals per sex per dose:

10; 10 additional rats/sex were included at each dose level for evaluation of hematological and clinical chemistry parameters at days 5 and 21.

Control animals:

yes, plain diet

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS/ CLINICAL OBSERVATIONS: Yes
- Time schedule: twice a day

BODY WEIGHT: Yes
- Time schedule for examinations: initially and 1 x wk thereafter.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes


OPHTHALMOSCOPIC EXAMINATION: No


HAEMATOLOGY: Yes
- Time schedule for collection of blood: from additional rats at days 5 and 21, and at the end of study
- Anaesthetic used for blood collection: Yes, CO2
- How many animals: 10 additional animals
- Parameters checked: red blood cell (RBC) count, red blood cell morphologic assessment, hematocrit (HCT), hemoglobin concentration (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), white blood cell count (WBC), white blood cell differential count, reticulocyte count (absolute), and platelet counts (absolute).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: from additional rats at days 5 and 21, and at the end of study
- How many animals: 10 additional animals
- Parameters checked: alkaline phosphatase activity (ALP), albumin (ALB), urea nitrogen (UN), creatinine (CREA), alanine aminotransferase activity
(ALT), total bile acids (TBA), sorbitol dehydrogenase activity (SDH), total protein (TP), and creatinine kinase (CK).


URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Complete histopathology examinations were conducted on all rats from the control and 10% dose groups. Livers were examined from male rats in all other dose groups; histologic sections of gross lesions were examined from all rats. Organ weights were determined to the nearest milligram for the liver, right kidney, right testicle, heart, thymus, and lungs. All tissues were preserved in 10% neutral buffered formalin.

The following tissues were routinely processed for preparation of histologic sections and microscopic examination: adrenal glands, brain, cecum, colon, duodenum, epididymis/seminal vesicles/prostate/testes or ovaries/uterus, esophagus, eyes (if grossly abnormal), femur (including marrow), heart, ileum, jejunum, kidneys, liver, lungs and mainstem bronchi, mammary gland, mandibular and mesenteric lymph nodes, nasal cavity and turbinates, pancreas, parathyroid glands, pituitary gland, preputial or clitoral glands, rectum, salivary glands, skin, spinal cord and sciatic nerve (if neurologic signs present), spleen, forestomach and glandular stomach, thymus, thyroid gland, trachea, urinary bladder, zymbal glands, and all gross lesions and tissue masses including regional lymph nodes. A complete histopathologic examination was conducted on all rats from the control and 10% dose groups. Liver was examined from male rats in all other dose groups, and histologic sections of gross lesions were examined from all rats.

Statistics:

Body weight and organ weight data were statistically analyzed within each sex by one-way Analysis of Variance tests, followed by Dunnett's t-test if pair-wise comparisons were indicated (p < 0.05)(Dunnett, 1955).

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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):

no adverse biologically significant effects, please refer to "Details on results".

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

no adverse biologically significant effects, please refer to "Details on results".

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

no adverse biologically significant effects, please refer to "Details on results".

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
No effects

BODY WEIGHT AND WEIGHT GAIN
Group mean body weights of rats receiving diets containing castor oil did not differ significantly from controls. Mean body weights of exposed female rats were slightly lower than the mean body weights of controls but the differences were not dose-related.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No significant differences in average food consumption among each sex were observed, although food consumption of male and female rats receiving diets containing 10% castor oil was slightly lower than that of controls.

HAEMATOLOGY
Hematological effects of the castor oil diets among male rats included a slight decrease in MCHC at day 21 in those receiving the 10% diet; a statistically significant decrease in MCV among the 10% group; a decrease in MCH among the 5% and 10% groups; and an increase in platelets among the 1.25%, 5%, and 10% groups. The only change observed among female rats was a statistically significant decrease in reticulocyte counts at day 5 in groups receiving the 0.62% or 10% diets. None of these changes was considered biologically significant.

CLINICAL CHEMISTRY
A treatment- and dose-related increase in the activity of serum alkaline phosphatase was observed in male and female rats at days 5 and 21, and at study termination. Total bile acids were increased among males receiving the higher dietary levels at days 5 and 21 but were not increased at study termination. Other minor changes included increases in albumin observed at study termination in males receiving 5% diets and at day 5 in females receiving 10% diets, and an increase in urea nitrogen at study termination in males that received 0.62% diets and a decrease at day 5 in females that received castor oil at 10% in the diet.

ORGAN WEIGHTS
Absolute liver weights and the liver-to-body-weight ratio were increased in male rats that received diets containing 10% castor oil. Heart-to-body-weight ratios were increased in groups of male rats receiving 0.62%, 2.5%, and 10% diets; however, absolute heart weights were not increased, and the differences in body weight ratios were small and not considered treatment related. Using light microscopy, it was determined there were no morphologic changes associated with the slight differences in organ weights between groups.

In male rats, there was a slight decrease in epididymal weight (6-7%) which occurred in the middle- and high-dose groups, but this was not dose-related. There were no effects on any other male rat reproductive endpoint, or on any female rat reproductive endpoint. Although there was some variation in epididymal weights, their small magnitude and the absence of changes in other endpoints suggested that there was little or no evidence of any reproductive toxicity associated with castor oil exposure. Histopathologic examination revealed an absence of compound-related lesions in any organ or tissue of rats exposed to castor oil in the diet.

Effect levels

Key result

Dose descriptor:

NOAEL

Effect level:

10 other: % (w/w) in the diet

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effects were observed up to and including the highest dose level.

Remarks on result:

other: corresponding to doses of 5835 and 5725 mg/kg bw/day in males and females, respectively, as calculated from the reported food consumption and body weights

Target system / organ toxicity

Key result

Critical effects observed:

no