Registration Dossier

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
December 1999
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
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:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
Dry powder, white to slightly yellow

Method

Target gene:
HIS, rfa, uvrB, R-factor
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
other: HIS G46/C3076/D3052
Species / strain / cell type:
E. coli WP2 uvr A
Additional strain / cell type characteristics:
other: Trp
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
0; 62; 185; 556; 1667; 5000 µg/L
top dose in accordance to test guideline in the absence of cytotoxicity.
Vehicle / solvent:
Water
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
sodium azide
benzo(a)pyrene
ethylnitrosurea
other: 2-aminoanthracene, 2.0µg/plate

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

positive control mutagens

strain

in the absence of the S9-mix

in the presence of the S9-mix

TA 1535

sodium azide: 1.0 tg/plate

2-aminoanthraTéene: 2.0 ug,,Iplate

TA 1537

9-aminoacridine: 801.14/plate

benzo(a)pyrene: 4.0 ..tg/plate

TA 98

2-nitrofluorene: 2.0 µg/plate

2-aminoanthracene: 2.0 µg/plate

TA 100

sodium azide: 1.0 µg/plate

2-aminoanthracene: 2.0 ug/91ate

WP2uvrA

N-ethyl-N-nitrosourea: 100 gg/plate

2-aminoanthracene: 80 µg/plate

Dose TA1535 TA1537 TA98 TA100 e.coli
µg/L S9- S9+ S9- S9+ S9- S9+ S9- S9+ S9- S9+
16 14 14 15 22 46 121 128 27 23
13 12 16 15 29 34 121 129 28 24
17 16 9 19 26 36 155 127 22 33
0 Mean 15 14 13 16 26 39 132 128 26 27
Sd 2 2 4 2 4 6 20 1 3 6
22 8 9 11 20 46 126 131 20 19
14 11 17 9 31 45 143 143 26 28
17 14 11 17 22 36 128 118 13 24
62 Mean 18 11 12 12 24 42 132 131 20 24
Sd 4 3 4 4 6 6 9 ·    13 7 5
22 6 9 12 27 28 126 121 27 27
18 8 16 18 33 40 122 104 31 19
18 10 13 19 35 45 132 123 37 18
185 Mean 19 8 13 16 32 38 127 116 32 21
Sd 2 2 4 4 4 9 5 10 5 5
19 11 11 16 25 37 122 143 19 28
20 12 12 17 14 27 100 121 26 29
14 22 18 20 24 42 126 124 25 26
556 Mean 18 15 14 18 21 35 116 129 23 28
Sd 3 6 4 2 6 14 12 4 2
22 14 17 15 25 58 122 129 28 36
12 9 8 16 38 31 132 132 25 19
17 6 9 24 33 35 118 138 27 22
1667 Mean 17 10 11 18 32 41 124 133 27 26
Sd 5 . 4 5 5 7 15 7 5 2 9
13 7 8 18 19 52 99 124 22 20
21 9 8 7 19 46 126 140 23 22
14 12 9 9 27 41 141 139 30 24
5000 Mean 16 9 8 11 22 46 122 134 25 22
Sd 4 3 1 6 5 6 21 9 4 2
387 212 769 270 888 1091 406 1577 212 944
398 216 707 219 873 1052 423 1453 173 950
411 222 633 192 980 981 397 1485 194 1049
Pos.C. Mean 399 217 703 227 914 1041 409 1505 193 981
Sd 12 5 68 40 58 56 13 64 20 59

Applicant's summary and conclusion

Conclusions:
It is concluded that the results obtained with the test substance D-Ribose in Salmonella typhimurium strains TA 1535, TA 1537, TA 98 and TA 100, and in the Escherichia coli strain WP2 uvrA, in both the absence and the presence of the S9-mix, indicate that D-Ribose was not mutagenic under the conditions employed in this study.
Executive summary:

The results of the mutagenicity assays are shown in Table 1 and 2.

Two independent assays were performed with all strains in both the absence and the presence of the S9-mix with five different concentrations of the test substance, ranging from 62 -5000 lag/plate (first assay) and 313 -5000 µg/plate (second assay). The test compound was dissolved in water. Negative controls (solvent) and positive controls were run simultaneously with the test substance.

A slight decrease in the mean number of revertant colonies observed in some strains in the second test indicates possible toxicity to these strains by the test substance D-Ribose.

In both assays, in the absence and the presence of the S9-mix and in all strains, D-Ribose did not cause a two-fold or greater increase in the mean number of revertant colonies appearing in the test plates compared to the background spontaneous reversion rate observed with the negative control, and did not give evidence of a dose-response relationship.

The mean number of his + and trp+ revertant colonies of the negative controls were within the acceptable range, and the positive controls gave the expected increase in the mean number of revertant colonies.