Dimethyl sulfoxide

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Salmonella mutagenicity tests: V. Results from the testing of 311 chemicals

Author:

Zeiger E; Anderson B; Haworth S; Lawlor T; Mortelmans K

Year:

1992

Bibliographic source:

Environ. Mol. Mutagen, Vol 19, Suppl. 21, pp. 2-141

Reference 2

Reference Type:

other: NTP web site

Title:

Results for this Salmonella study's detailed data, CAS no. 67-68-5

Author:

NTP

Year:

1987

Bibliographic source:

http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchhome&crumbspot=1

Reference 3

Reference Type:

other: NTP web site

Title:

Results for this Salmonella study's detailed data, CAS no. 67-68-5

Author:

NTP

Year:

1988

Bibliographic source:

http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchhome&crumbspot=1

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Dimethyl sulfoxide

EC Number:

200-664-3

EC Name:

Dimethyl sulfoxide

Cas Number:

67-68-5

Molecular formula:

C2H6OS

IUPAC Name:

dimethyl sulfoxide

Details on test material:

Test compound: Dimethylsulfoxide
CAS no.: 67-68-5
Source: Burdick and Jackson
Purity: > 99.5%

Method

Target gene:

Histidine operon

Species / strain

Species / strain / cell type:

S. typhimurium, other: Strains TA97, TA98, TA100, TA1535, TA1537

Metabolic activation:

with and without

Metabolic activation system:

S9 fractions of Aroclor 1254-induced male Sprague Dawley rats and male Syrian hamster livers

Test concentrations with justification for top dose:

0, 100, 333, 1000, 3333 and 10000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: no data

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: - Without S9: Sodium azide (TA 1535 and TA100), 9-aminoacridine or ICR-191 (TA 97 and TA1537), 4-nitro-o-phenylenediamine (TA98) - With S9: 2-aminoanthracene (all strains)

Details on test system and experimental conditions:

In the Salmonella assay, a test tube containing a suspension of one strain of Salmonella typhimurium plus S9 mix or plain buffer without S9, is incubated for 20 minutes at 37º C with the test chemical. Control cultures, with all the same ingredients except the test chemical, are also incubated. In addition, positive control cultures are also prepared; these contain the particular bacterial tester strain under investigation, the various culture ingredients, and a known potent mutagen. After 20 minutes, agar is added to the cultures and the contents of the tubes are thoroughly mixed and poured onto the surface of Petri dishes containing standard bacterial culture medium. The plates are incubated for 48 hours and then counted.

Initial testing was without metabolic activation, with 10% rat liver S-9, or with 10% hamster liver S-9. After a negative result was obtained, DMSO was retested without S-9 and with 30% S-9 from rat and hamster.

The positive control plates are counted, and the number of mutant colonies appearing on them must be significantly increased over the spontaneous control number for the test to be considered valid.

Evaluation criteria:

If no increase in mutant colonies is seen after testing several strains under several different culture conditions, the test chemical is considered to be non-mutagenic in the Salmonella test.

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA97, TA98, TA100, TA1535, TA1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

The positive control chemicals induced a significant increase of the revertant frequency in all tester strains, either with or without metabolic activation.
DMSO was negative, in the presence and absence of metabolic activation, in all tester strains.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Individual strain data is presented as mean ± standard error.
Abbreviations are noted at bottom of page.
Trial summary calls are shown in parentheses.
Strain: TA1535
Dose	No Activation		No Activation		10% HLI		30% HLI		10% RLI		30% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	22	5.2	19	5	16	0.6	14	1	10	1.8	15	2.3
100	19	5.4	24	2.3	12	3.3	14	4.3	12	3.5	14	1.8
333	27	1.7	24	3.2	15	2	14	1.8	11	2.6	15	1
1000	19	1.8	17	2.6	12	1.5	13	0.9	14	1.7	15	1.7
3333	22	2.5	22	2.5	9	1.5	16	3.8	11	1.9	15	0.9
10000	24	1.8	18	2.9	9	3.8	15	2.5	11	0.9	15	4.4
Positive Control	852	11.7	272	16.2	52	3.2	180	6.9	328	17.1	308	4.1
Strain: TA100
Dose	No Activation		No Activation		10% HLI		30% HLI		10% RLI		30% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	138	3	113	6.1	105	1.2	142	9.8	113	5	138	3.8
100	133	6.7	107	5.6	110	2.3	145	8.4	121	9.6	140	5
333	155	7.6	106	5.6	111	10.6	155	4.9	119	4.5	147	11.9
1000	139	3.5	110	9.3	105	1.8	159	5.1	116	2.7	128	4
3333	126	10.5	107	7.9	93c	3.5	147	13.5	108	0.9	128	5.8
10000	157	12.3	113	6.9	102	4.2	136	4.8	107	4.7	129	6.1
Positive Control	586	3.5	414	12.2	279	10.3	728	12.7	1440	66.4	1005	15.6
Strain: TA97
Dose	No Activation		No Activation		10% HLI		30% HLI		10% RLI		30% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	122	3	118	6	112	3.4	122	5.1	115	7.6	158	11.9
100	141	1.2	114	5	130	4.7	111	5.5	137	3.5	183	2.6
333	131	15	123	3.9	109	5.8	141	3.7	128	2.9	180	11.8
1000	117	3.4	123	12	129	7	136	1.2	131	3.5	155	10.7
3333	150	11.7	131	3.5	118	7.8	132	5.1	119	4.7	167	3.5
10000	138	9.6	118	8	120	2.2	119	8.7	132	6	158	3.9
Positive Control	960	22.6	512	18.1	812	35	1436	48.3	2756	30.8	1606	101.3
Strain: TA98
Dose	No Activation		No Activation		10% HLI		30% HLI		10% RLI		30% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	19	0.9	23	1.7	35	2.7	35	1.7	27	3.8	32	1.9
100	13	2.3	21	1.7	36	1.5	34	3.7	27	0.9	31	1.9
333	15	3.5	16	2.1	35	7.2	32	1.7	32	2	31	1
1000	21	4.2	17	3.8	33	4.3	34	4.9	33	4.7	29	1.8
3333	25	2.4	19	1.7	32	2.8	31	6.8	35	3.2	34	4.2
10000	17	3	21	4.2	31	2.9	31	0.7	32	1.7	27	1.2
Positive Control	330	13.1	330	8.4	110	2.6	604	17.9	211	8.2	338	12.6

Strain: TA1535
Dose	No Activation		No Activation		10% HLI		30% HLI		10% RLI		30% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	33	3.3	22	3.5	11	1.7	13	1.3	12	3.8	15	0.6
100	27	2	21	4.3	12	3.2	15	1.8	11	4.3	12	1.2
333	30c	1.5	26	3.2	12	3.2	13	2.2	10	1.2	12	0
1000	28	4.4	15	1.2	8	2	12	1.2	8	1.5	14	2.3
3333	21	2.3	15	2	10	0.7	12	1.2	9	1.8	14	2.2
10000	26	2.6	20	3.5	9	0.9	14	1.8	10	0.7	11	2.1
Positive Control	448	9	232	10.2	154	28.2	569	15.6	153	8.9	195	12.9
Strain: TA100
Dose	No Activation		No Activation		10% HLI		30% HLI		10% RLI		30% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	134	4.4	159	6.4	175	1.9	128	4.3	163	7.5	125	13.4
100	126	8.4	149	5.8	137	9.8	123	8.1	139	6.8	127	6.2
333	139	2.6	144	8.2	166	5.5	139	6.4	159	3.9	130	7.8
1000	128	5.8	140c	3	152	14.2	121	11.2	160	9.8	135	14.8
3333	121	2.8	159	4.2	167	4	135	11.2	140	17.9	152	6.1
10000	132	2.8	152	4.6	151	13.7	128	4.3	144	24.1	134	8
Positive Control	370	18.4	384	57.2	712	46	558	32.7	566	12.1	383	13.7
Strain: TA97
Dose	No Activation		No Activation		10% HLI		30% HLI		10% RLI		30% RLI
	(Equivocal)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	153	6.4	178	4.8	204	1.9	198	8.2	203	2.6	222	1.5
100	162	5.8	182	7.6	194	5.5	208	12.7	212	5.5	214	4.4
333	165	6.8	197	6.7	218	2.1	212	6.1	216	2.7	215	10.1
1000	196	10.1	195	9.4	199	7.8	212	3.2	229	7.9	198	4.5
3333	196	4.3	198	11.3	215	2.5	211	4.8	222	7.5	234	7.5
10000	182	7.9	207	9.9	212	6.2	193	2.2	229	3.2	217	8.8
Positive Control	635	28.5	613	34.8	556	35.6	516	8.5	376	27	460	34.5
Strain: TA98
Dose	No Activation		No Activation		10% HLI		30% HLI		10% RLI		30% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	16	3.2	16	2.3	28	2	34	3.6	39	3.2	39	4.9
100	16	1.2	17	1.3	25	2.3	28	1	31	3.6	31	3.3
333	18	3.8	18	3	30	4	36	1.5	34	5.6	36	2.9
1000	19	3.3	13	3.2	34	2.6	33	1.9	29	5.2	33	7.7
3333	15	1.3	21	2.7	33	1.5	33	2.5	23	3.6	27	0.7
10000	17	2.1	17	4.2	26	4.7	28	1.7	35	4	31	4.2
Positive Control	540	11.6	745	51.8	771	3.7	438	12.6	534	4	122	5.8
Strain: TA1537
Dose	No Activation		30% HLI		30% RLI
	(Negative)		(Negative)		(Negative)
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM
0	11	1.5	10	1.7	14	0.6
100	12	1	14	1.2	15	2.3
333	12	2.8	11	0.3	13	2.6
1000	9	1.9	9	1.5	10	1.2
3333	12	0.9	13	0.9	11	1.9
10000	14	2.3	10	0.9	12	2.1
Positive Control	310	30.5	46	8.9	55	4.6
Abbreviations:
RLI = induced male Sprague Dawley rat liver S9
HLI = induced male Syrian hamster liver S9
s = Slight Toxicity; p = Precipitate; x = Slight Toxicity and Precipitate; T = Toxic; c = Contamination

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Under these experimental conditions, Dimethylsulfoxide is considered as non genotoxic.

Executive summary:

The potential of Dimethylsulfoxide (DMSO) to induce reverse mutation in Salmonella typhimurium (strains: TA97, TA98, TA100, TA1535, TA1537) was evaluated according to a protocol comparable to the OECD guidelines 471.

DMSO was tested in two consecutive experiments, with and without a metabolic activation system, according to the preincubation method (20 min at 37°).

Concentrations of DMSO (100, 333, 1000, 3333, and 10,000 µg), overnight culture of S. typhimurium (0.05-0.10 ml) and S-9 mix or buffer were incubated without shaking for 20 minutes. The top agar was added and the contents of the tubes were mixed and poured onto the surfaces of Petri dishes. His+ (histidine dependent) colonies arising on plates were machine-counted after two days incubation at 37°C.

Initial testing was without metabolic activation, with 10% rat liver S-9, or with 10% hamster liver S-9. After a negative result was obtained, DMSO was retested without S-9 and with 30% S-9 from rat and hamster.

The positive control chemicals induced a significant increase of the revertant frequency in all tester strains, either with or without metabolic activation. DMSO was negative, in the presence and absence of metabolic activation, in all tester strains.