Xylose

Toxicity to reproduction: other studies

Administrative data

Endpoint:

toxicity to reproduction: other studies

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Lack of carcinogenicity of D-xylose given in the diet to F344 rats for two years

Author:

Kuroiwa Y, Nishikaw A, Imazawa T, Kitamura Y, Kanki K , Umemura T, Hirose M

Year:

2005

Bibliographic source:

Food Chem Toxicol., 43(9):1399-1404

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Ministry of Health, Labor and Welfare of Japan), 1996b. Guidelines for Designation of Food Additives, and for Revision of Standard for Use of Food Additives, Article No. 29 of the Life and Sanitation Bureau.

Deviations:

no

GLP compliance:

not specified

Type of method:

in vivo

Test material

Test material information

Constituent 1

Reference substance name:

Xylose

EC Number:

200-400-7

EC Name:

Xylose

Cas Number:

58-86-6

Molecular formula:

C5H10O5

IUPAC Name:

(2S,3R,4S; 5R)-oxane-2,3,4,5-tetrol

Details on test material:

- Purity: >99%

Test animals

Species:

rat

Strain:

Fischer 344/DuCrj

Sex:

male/female

Details on test animals or test system and environmental conditions:

For additional details refer to Section 7.5.1: DL.K2.104Wk.Feed.RD/CARC.R.Pub.KD

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

For additional details refer to Section 7.5.1: DL.K2.104Wk.Feed.RD/CARC.R.Pub.KD

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

104 Weeks

Frequency of treatment:

Daily

Duration of test:

104 Weeks

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

2.5 other: %

Remarks:

equivalent to 1033 and 1203 mg/kg/day in males and females, respectively

Doses / concentrations 2

Dose / conc.:

5 other: %

Remarks:

equivalent to 2214 and 2513 mg/kg/day in males and females, respectively

No. of animals per sex per dose:

50/sex/dose

Control animals:

yes, plain diet

Details on study design:

For additional details refer to Section 7.5.1: DL.K2.104Wk.Feed.RD/CARC.R.Pub.KD

Statistics:

For additional details refer to Section 7.5.1: DL.K2.104Wk.Feed.RD/CARC.R.Pub.KD

Results and discussion

Effect levels

Dose descriptor:

NOAEL

Effect level:

> 5 other: % nominal (2214 and 2513 mg/kg/day for males and females, respectively)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effects were observed on reproductive organs at the highest dose tested.

Observed effects

No test substance-related effects were observed on male and female reproductive organs at the highest dose tested. For additional details on systemic toxicity or tumour incidence refer to Section 7.5.1: DL.K2.104Wk.Feed.RD/CARC.R.Pub.KD

Applicant's summary and conclusion

Conclusions:

No test substance related effects were observed on male and female reproductive organs at 5% in diet (the highest dose tested).

Executive summary:

The test substance was administered to F344 rats at dose levels of 2.5% or 5% (equivalent to overall achieved intakes of 1033 or 2214 mg/kg/day for males and 1203 or 2513 mg/kg/day for females, respectively) in the diet for 104 weeks. No effects on mortality, clinical signs or haematology data, except soft feces in 5% males and females were observed. Although decreases in the final body weights were recorded in males and females receiving the 5% dose, the values during the experimental period were less than 10% lowered as compared with the control group. This weight suppression might be a result from the low calorific property of the test substance. However, the effect of the test substance on total calorie intake was considered to be a little, because the quantity of the test substance in the admixture was only 5% at the maximum, and food consumptions seem to have increased with the test substance concentrations in order to compensate low calorie. Increases in the absolute and relative testis weights were observed in males of the 5% group. In rats, spontaneous interstitial cell tumours in the testes occur at very high incidence, reaching 81–91% at 104 weeks of age. In the present study, the incidence of interstitial cell tumours in the control group was 92% (within the reference background range), whereas that in the 5% group was decreased to 72%. This low incidence was considered to reflect differences in testis weights between the control and 5% groups. Dietary restriction has been shown to reduce the incidences of a variety of rodent spontaneous tumours, including interstitial cell tumours in F344 rats. Additionally, the suppression of body weight is considered to be associated with low neoplasm incidences. In the present study, the suppression of body weight may have caused a low incidence of testis interstitial cell tumour. However, suppression of body weight gain is much weaker than those in dietary restriction experiments. Therefore, it is likely that unknown factors other than lower body weight might be also concerned. No test substance related-effects were observed in male or female reproductive organs at histopathologic examination.