DS-2920A-E

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

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

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Version / remarks:

Adopted 27 July 1995

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): DS-1115A-E-1
- Physical state: red solid
- Analytical purity: 92.6% (reported in the study report for the Ames test, performed by Safepharm Laboratories Ltd., 1998, with the same batch)
- Lot/batch No.: 005
- Storage condition of test material: 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 Ltd. (UK), Margate, Kent, UK
- Age at study initiation: 5-7 weeks
- Weight at study initiation: males 179-220 g, females 142-197 g
- Housing: groups of 5
- Diet (e.g. ad libitum): Rat and Mouse SQC Expanded Diet No. 1, Special Diet Services Ltd., Witham, Essex, UK, ad lib.
- Water (e.g. ad libitum): water, ad lib.
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21+/-2
- Humidity (%): 55 +/- 15
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: weekly, storage at 4°C

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

28 days

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 150, 500, 1000 mg/kg bw/d
Basis:
actual ingested

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: based on the results of a range-finding study
- Post-exposure recovery period in satellite groups: no

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: immediately before dosing and 1-5 hrs after dosing (on working days) or 1 hour after dosing (on weekend days)

DETAILED CLINICAL OBSERVATIONS for functional/ bahavioural toxicity: Yes
- Time schedule: on days 6, 13, 20 and 27 (here: including test for sensory sensitivity to different stimuli); approx. two hrs after dosing
- Functional Performance tests include Motor activity observations and tests for Forelimb/ Hindlimb Grip strength
- Sensory reactivity was assessed to auditory, visual and proprioceptive stimuli

BODY WEIGHT: Yes
- Time schedule for examinations: on days 7, 14, 21, 28

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean weekly diet consumption calculated as g food/kg body weight/week: Yes, groupwise

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, per group

WATER CONSUMPTION: Yes, groupwise
- Time schedule for examinations: daily

HAEMATOLOGY and CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: day 28
- Anaesthetic used for blood collection: No
- Animals fasted: No
- How many animals: all
- Parameters checked:
Haematology: Haemoglobin, erythrocyte count, Haematocrit, mean corpuscular haemoglobin, mean corpuscular volume, mean corpuscular concentration, Total leucocyte count, Differential leukocyte count: neutrophils/ lymphocytes, monocytes, eosinophils, basophils, platelet count, methaemoglobin, reticulocyte count, Prothrombin time, Activated partial thromboplastin time
Clinical Chemistry: urea, glucose, total protein, albumin, albumin/globulin ratio, sodium, potassium, chloride, calcium, Inorganic Phosphorus, Creatinine, total cholesterol, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (all animals)
Organ weights: Adrenals, kidneys, testes, brain, liver, thymus, epididymides, ovaries, heart, spleen

HISTOPATHOLOGY: Yes (control and high dose animals plus any macroscopic lesions; liver and spleen from all animals)
Adrenals, aorta, bone & bone marrow (femur incl. stifle joint), brain (incl. cerebrum, cerebellum and pons), caecum, colon, duodenum, epididymis, eyes, gross lesions, heart, ileum, jejunum, kidneys, liver, lungs, lymph nodes, muscle (skeletal), oesophagus, ovaries, pancreas, pituary, prostate, rectum, salivary glands, sciatic nerve, seminal vesicles, skin (hind limb), spinal cord, spleen, stomach, testes, thymus, thyroid/ parathyroid, trachea, urinary bladder and uterus

Statistics:

One-way ANOVA for haematological and blood chemical parameters, organs weights, body weight gain, functional performance and sensory reactivity data, incorporating Levene´s test for homogeneity of variance. In case of homogenous variance, Dunnett´s tests for pairwise comparisons were done. In case of unequal variances, Kruskal-Wallis ANOVA and/or Mann-Whitney "U" test for non-parametric data were performed.

Results and discussion

Results of examinations

Details on results:

CLINICAL SIGNS AND MORTALITY
Red faeces in all treatment groups and staining of the external body surface in mid and high dose animals were considered as not indicative for toxicity of the test item.
No other clinical signs, no mortality and no effects on functional observations observation.

BODY WEIGHT AND WEIGHT GAIN
No treatment-related effects observed.
Males treated with 500 mg/kg/day showed statistically significant increases in bodyweight gain when compared with controls. An increase in bodyweight gain is unlikely to be associated with test material toxicity and, in any case, a dose response relationship was not evident.

FOOD CONSUMPTION
No effects observed.

WATER CONSUMPTION
No effects observed.

HAEMATOLOGY and CLINICAL CHEMISTRY
No treatment-related effects observed.
Males treated with 1000 mg/kg/day showed a slight but statistically significant increase in neutrophil count when compared with controls There was no histopathological evidence of inflammation and in the absence of a concomitant shift in total or differential leucocyte counts, this minimal (p < 0.05) intergroup difference was considered to have arisen fortuitously.

ORGAN WEIGHTS
No relevant treatment-related effects observed.
Males treated with 1000 mg/kg/day showed slight but statistically significant reductions in epididymis and thymus weight, relative to terminal bodyweight, when compared with controls. Males at the 500 mg/kg/day dose level also showing a reduced relative epididymis weight. There were no macroscopic or microscopic correlates and accordingly these minimal intergroup differences (p<0.05) were considered to be of no toxicological importance.

GROSS PATHOLOGY
No effects observed.

HISTOPATHOLOGY
No effects observed.

Effect levels

Dose descriptor:

NOAEL

Remarks:

systemic

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no relevant effects observed

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

The haematological parameter "basophils" was not statistically analysed since >30% of the data were recorded as the same value.