Lysozyme, hydrochloride

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian germ cell study: cytogenicity / chromosome aberration

Remarks:

Type of genotoxicity: chromosome aberration

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:

The test parameters documented do not totally comply with the specific testing guideline, but they are sufficient to accept the data. The test was conducted according to internationally accepted testing guidelines. Details about the read across approach are reported in the summary.

Data source

Reference

Reference Type:

publication

Title:

Safety Evaluation of a Alkaline cellulase

Author:

Greenough R.J., Everett D.J. and Stavnsbjerg M.

Year:

1991

Bibliographic source:

Fd Chem. Toxic. Vol. 29, No. 11, pp. 781-785, 1991

Materials and methods

Principles of method if other than guideline:

Groups of five male and five female rats were dosed orally by gavage with the test item, for five consecutive days with 0, 0.3, 1.0 or 3.0 g/kg body weight/day and killed 6 hours after the final dose. A further group was given a single i.p. dose of 100 mg methyl methanesulphonate/kg as a positive control. Slides of bone marrow cells were prepared and examined microscopically for chromosomal damage and mitotic indices were derived.

GLP compliance:

not specified

Type of assay:

chromosome aberration assay

Test material

Test material information

Constituent 1

Reference substance name:

Alkaline cellulase

IUPAC Name:

Alkaline cellulase

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Administration / exposure

Route of administration:

oral: gavage

Duration of treatment / exposure:

Five days

Frequency of treatment:

Daily

Post exposure period:

Animals were killed 6 hr after the final dose.
One hour before the rats were killed they were treated with democolcine to arrest cells in metaphase.

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 0.3, 1.0 or 3.0 g/kg bw/day
Basis:

No. of animals per sex per dose:

Groups of five male and five female.

Positive control(s):

A further group of five male and five female rats was given a single i.p. dose of 100 mg methyl methanesulphonate/kg as a positive control and these rats were killed after 24 hr.

Examinations

Tissues and cell types examined:

Slides of bone marrow cells were prepared and examined microscopically for chromosomal damage and mitotic indices were derived.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

not specified

Positive controls validity:

valid

Additional information on results:

There were no significant increases in chromosome aberrations, excluding gaps, in males or females at any dose level of the test item.
Female rats treated with the test item showed increases in aberrations including gaps at all doses but with no clear dose relationship and only statistically significant (chi squared = 5.02; P = 0.025) at 3.0 g/kg/day.
Treatment with the test substance had no effect on the mitotic capacity of bone marrow cells and it was concluded that the substance was not a chromosome mutagen for the rat in vivo.

The positive control rats showed clear chromosome damage.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative
The test substance is not a chromosome mutagen for the rat in vivo.

Executive summary:

Groups of five male and five female Sprague-Dawley rats were dosed orally by gavage with the test item, for five consecutive days with 0, 0.3, 1.0 or 3.0 g/kg body weight/day and killed 6 hours after the final dose. A further group was given a single i.p. dose of 100 mg methyl methanesulphonate/kg as a positive control and these rats were killed after 24 hours. Slides of bone marrow cells were prepared and examined microscopically for chromosomal damage and mitotic indices were derived.

The positive control rats showed clear chromosome damage.

There were no significant increases in chromosome aberrations, excluding gaps, in males or females at any dose level. Female rats showed increases in aberrations including gaps at all doses but with no clear dose relationship and only statistically significant at 3.0g/kg/day. Treatment with the test substance had no effect on the mitotic capacity of bone marrow cells.

Conclusion

The test substance is not a chromosome mutagen for the rat in vivo.