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Toxicological information

Genetic toxicity: in vivo

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Endpoint:
in vivo mammalian cell study: DNA damage and/or repair
Remarks:
Type of genotoxicity: DNA damage and/or repair
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: scientifically acceptable publication

Data source

Reference
Reference Type:
publication
Title:
Methanol Exposure Does Not Lead to Accumulation of Oxidative DNA Damage in Bone Marrow and Spleen of Mice, Rabbits or Primates.
Author:
McCallum, G.P., Siu, M., Ondovcik, S.L., Sweeting, J.N., Wells, P.G.
Year:
2010
Bibliographic source:
Molecular Carcinogenesis 9999: 1 - 10

Materials and methods

Principles of method if other than guideline:
This study was performed to determine whether MeOH could indirectly DNA damage via ROS-mediated mechanism. Animals (mice, rabbits and monkeys) were treated with either once or for 15 days with 2.0 g/kg MeOH i.p.. Oxidative DNA damage was observed by measuring 8-oxo-2'-deoxyguanosine. Lipid peroxidation in bone marrow and spleen homogenates was determined by measuring the Ievels of HNE-His protein adducts.
GLP compliance:
not specified
Type of assay:
other: oxidative DNA damage

Test material

Constituent 1
Chemical structure
Reference substance name:
Methanol
EC Number:
200-659-6
EC Name:
Methanol
Cas Number:
67-56-1
Molecular formula:
CH4O
IUPAC Name:
methanol
Details on test material:
- Name of test material (as cited in study report): MeOH
- Physical state: liquid
- Analytical purity: HPLC grade

Test animals

Species:
other: mouse, rabbit, monkey
Strain:
other: CD-1, New Zealand white, cynomolgus
Sex:
male
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: mice, rabbits and monkeys: Charles River Laboratories
- Age at study initiation: mice: 9 - 13 weeks; rabbits: 5 months; monkeys: 3.4 - 5.7 years
- Weight at study initiation: rabbits: 3.25 - 3.75 kg, monkeys: 2.8 - 4.8 kg
- Diet: mice: rodent chow ad libitum; rabbit: standard high-fiber rabbit chow; monkeys: certified primate chow diet (# 5048) from Purina Mills (St. Louis, MO) supplemented with fruit or vegetables 2-3 times weekly
- Water: mice, rabbit and monkeys: ad libitum
- Acclimation period: monkeys: two weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): mice and rabbits: 20°C; monkeys: 18 - 29°C
- Humidity (%): mice: 50%, rabbits: 60%
- Photoperiod (hrs dark / hrs light): mice: 10/14; rabbits and monkeys: 12/12

Administration / exposure

Route of administration:
intraperitoneal
Vehicle:
- Vehicle(s)/solvent(s) used: saline
Details on exposure:
Mice: Drugs were administered via intraperitoneal (ip) injection using a 26 gauge (G) 3/8 needle.
Rabbits: by ip injection usinga 23 G needle
monkeys: were lightly sedated with ketamine (ca. 5 - 10 mg/kg) for dose administration and then administered MeOH (2g/kg bw; 20% [w/v] in sterile saline) or a saline vehicle by ip injection using a 22G needle.
Duration of treatment / exposure:
single or 15 consecutive days
Frequency of treatment:
daily
Post exposure period:
6 hours or 15 days
Doses / concentrations
Remarks:
Doses / Concentrations:
2 g/kg bw
Basis:
nominal conc.
No. of animals per sex per dose:
Three rabbits and primates were used in each treatment group. Four and five mice were used in each group for the acute and chronic studies, respectively.
Control animals:
yes, concurrent vehicle
Positive control(s):
KBrO3
- Justification for choice of positive control(s): is a known renal carcinogen
- Route of administration: i.p.
- Doses / concentrations: 100 mg/kg bw at a fixed volume of 0.1 mL/10g bw

Examinations

Tissues and cell types examined:
DNA from spleen and bone marrow
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION: The effect of a Iimit dose of 2.0 g/kg bw MeOH based on guidelines established for the comet assay developed in accordance with the in vivo genetic toxicology guidelines of the Organization for Econornic Co-operation and Development (OECD) were studied.

METHOD OF ANALYSIS: DNA was isolated using DNAzol, a novel guanidine-detergent lysing solution that hydrolyzes RNA and allows for the selective precipitation of DNA from cell lysates. 8-oxodG and dG were analysed via HPLC system. Lipid peroxidation in bone marrow and spleen homogenates was determined by measuring the Ievels of HNE-His protein adducts.
Statistics:
Statistical analysis was performed using GraphPad Instat Version 3.05 (GraphPad Software, lnc., San Diego, CA). Experiments comparing two groups were analyzed by unpaired t tests and multiple comparisons were anaJyzed by one-way ANOVA followed by a Tukey post-test. The Ievel of significance was set at P<0.05.

Results and discussion

Test results
Sex:
male
Genotoxicity:
negative
Toxicity:
not examined
Vehicle controls validity:
valid
Negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
No increase in oxidative DNA damage was observed in bone marrow or spleen at 6 h following exposure to MeOH (2.0g/kg bw ip) in mice, rabbits,
or primates. Similarly, no increase in oxidative DNA damage was observed in bone marrow or spleen 24 h following exposure to a single dose of MeOH (2.0g/kg bw ip), or following 15 consecutive daily doses of 2.0g/kg bw ip MeOH in CD-1 mice. No increase in HNE-His protein adducts was observed in bone marrow or spleen at 6 h following exposure to MeOH (2.0 g/kg bw ip) in primates. MeOH exposure (2.0 g/kg bw ip) increased HNE-His protein adducts 1.4-fold 6 h post-dose in bone marrow of mice, with adduct Ievels returning to basal values within 24 h. No increases in HNE-His protein adducts were observed in spleen of mice or bone marrow of rabbits following MeOH exposure (2.0 g/kg bw ip). MeOH exposure (2.0 g/kg bw ip) increased HNE-His protein adducts 1.5-fold 6 h post-dose in spleen of rabbits.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
Taken together these observations suggest that it is unlikely that exposure to MeOH would initiate Iymphomas, particularly in humans, via formation
of mutagenic oxidative DNA lesions.