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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented publication meeting basic scientific principles. Study was part of subchronic oral toxicity study. Test compound was a mixture of short- and long-chain acyl triglyceride.

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Genetic Toxicology Studies of SALATRIM Structured Triacylglycerols. Lack of Genetic Damage in in Vitro Mammalian Cell Assays and the in Vivo Micronucleus Assay
Author:
Hayes, J.R. et al.
Year:
1994
Bibliographic source:
J. Agrlc. Food Chem. 42, 521-527
Reference Type:
publication
Title:
Subchronic Toxicity Studies of SALATRIM Structured Triacylglycerols in Rats. 3. Triacylglycerols Composed of Stearate, Acetate, Propionate, and Butyrate
Author:
Hayes, J.R. et al.
Year:
1994
Bibliographic source:
J. Agric. Food Chem. 42, 552-562

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Version / remarks:
although test was performed within a oral subchronic toxicity study
Deviations:
yes
Remarks:
, no positive controls
Principles of method if other than guideline:
The SALATRIM family of triacylglycerols differs from other fats in the ratio of short-chain fatty acids (SCFA) to long-chain fatty acids (LCFA) and in that stearic acid is the major LCFA. These fats have caloric availability values (4.5-6 kcal/g) lower than that of corn oil (9 kcal/g). SALATRIM 234CA lot A019 and SALATRIM 234CS lot A018 were tested in the in vivo bone marrow micronucleus assay. Rats received these SALATRIM fats or corn oil at 10% (w/w) in the diet for 13 weeks.
The in-life and bone marrow smear preparation portions of the study were part of a 13-week subchronic toxicity study conducted at Hazleton Wisconsin, Inc., Madison, WI, and the micronucleus assay portion of the study was conducted at Hazleton Washington, Vienna, VA. Detailed information on the experimental design and methods for the subchronic study can be found in the paper for the subchronic toxicology portion of that study (Hayes et al., 1994).
GLP compliance:
not specified
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
other: Crl:CD BR VAF/Plus
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories, Portage, MI, USA
- Diet: ad libitum

Administration / exposure

Route of administration:
oral: feed
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
SALATRIM fats and corn oil were mixed separately with NIH-07 Rat and Mouse Ration 5018 (Purina Mills, Inc., St. Louis, MO) and fed ad libitum.
Duration of treatment / exposure:
13 weeks
Groups of 20 male and 20 female Crl:CD BR VAF/Plus rats from Charles River Laboratories, Portage, MI, were exposed to either of the two SALATRIM fats or corn oil at 10% (w/w) of the diet for at least 13 weeks.
Frequency of treatment:
mixed in diet
Post exposure period:
none
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
10 % (w/w)
Basis:
nominal in diet
Remarks:
Doses / Concentrations:
approx. 7000 mg/kg bw/d
Basis:
other: actual ingested as calculated by measured food consumption
No. of animals per sex per dose:
20
Control animals:
other: 10% corn oil in diet as negative control group
Positive control(s):
Because these data were collected from a 13-week subchronic toxicity study, a positive control for micronuclei formation was not included.

Examinations

Tissues and cell types examined:
bone marrow
Details of tissue and slide preparation:
TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields):
At necropsy, duplicate bone marrow slides for each rat were prepared for clinical pathology. One set of unstained bone marrow slides was shipped to Hazelton Washington for the micronucleus assay.

DETAILS OF SLIDE PREPARATION/METHOD OF ANALYSIS:
Upon arrival, the slides were fixed in methanol and stained with acridine orange. A bone marrow slide from each of the 20 rata per group (with the exception of the SALATRIM 234CS lot A018 group, where only 18 slides were available) was analyzed using fluorescent microscopy. One thousand polychromatic erythrocytes per rat were scored for micronuclei. Identification of micronuclei was based upon the criteria of Schmid (1976). The scoring unit was the micronucleated cell, not the number of micronuclei. Therefore, a cell that contained more than one micronucleus was scored as a single micronucleated cell. The frequency of micronucleated cells was expressed as percent micronucleated cells based upon the total number of polychromatic erythrocytes scored. The normal frequency of micronucleated erythrocytes for this strain of rat is 0.0 - 0.4 % .
Analyses were conducted separately for each SALATRIM-treated group and each sex combination.
Evaluation criteria:
The criteria for a positive response was a significant increase in micronucleated polychromatic erythrocytes compared with the corn oil control group. If no increase was found, the test fats were considered negative in this assay.
Statistics:
Statistical analysis of the data was by analysis of variance on the square root arcsine transformation.
Tukey’s Studentized range test (Sokal and Rohlf, 1981) was used to determine statistical significance (p < 0.05) from the corn oil control group.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
not examined
Negative controls validity:
valid
Positive controls validity:
not examined
Additional information on results:
Comparison of the data for the two SALATRIM fats with that from the corn oil group indicated that neither SALATRIM fat increased the incidence of micronucleated polychromatic erythrocytes. Therefore, the SALATRIM fats were considered to be negative in the assay.

Any other information on results incl. tables

Table 3:Percent Micronucleated Polychromatic Erythrocytes in Bone Marrow of Rats Fed Diets Containing 10% SALATRIM 234CA Lot A019, SALATRIM 234CS Lot

A018, and Corn Oil for 13 Weeks*

 

treatment

males

(% MN/1000 PCE)

females

(% MN/1000 PCE)

combined

male and female

(% MN/1000 PCE)

corn oil

0.18 ± 0.11

0.17 ± 0.13

0.17 ± 0.12

SALATRIM 234CA lot A019

0.25 ± 0.17

0.17 ± 0.11

0.21 ± 0.14

SALATRIM 234CS lot A018

0.21 ± 0.17

0.12 ± 0.12

0.16 ± 0.14

MN = micronucleated cells

PCE = polychromatic erythrocytes

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
Both fats were negative in this assay. The data confirm the prediction that SALATRIM fats lack genotoxic potential.