title: Combination comet/micronucleus assay validation performed by BioReliance under the JaCVAM initiative.
abstract: In the international validation study of the in vivo rat alkaline comet assay (comet assay), the Japanese Center for the Validation of Alternative Methods (JaCVAM) provided three coded chemicals to BioReliance, 1,3-dichloropropene, ethionamide and busulfan, to be tested in a combined in vivo comet/micronucleus assay. Induction of DNA damage (comet) in liver, stomach and jejunum (1,3-dichloropropene only) cells, and induction of MNPCEs in bone marrow, were examined in male Sprague-Dawley (Hsd:SD) rats following oral administration of the test chemical for three consecutive days. A dose range finding (DRF) test was performed with each chemical to determine the maximum tolerated dose (MTD). Based on the results of the DRF test; 1,3-dichloropropene was tested at 50, 100 and 200 mg/kg/day; ethionamide was tested at 125, 250 and 500 mg/kg/day, and busulfan was tested at 10, 20 and 40 mg/kg/day. The results indicated that 1,3-dichloropropene induced DNA damage only in liver cells at all three test article doses, while no effects were observed in the stomach and jejunum cells. Additionally, it did not increase MNPCEs in the bone marrow. 1,3-Dichloropropene was concluded to be negative in the MN assay but positive in the comet assay. Ethionamide did not induce DNA damage in liver. However, in stomach, statistically significant decreases (although still within historical range) in % tail DNA at all test article doses compared to the vehicle control were observed. There was no increase in MNPCEs in the bone marrow. Thus, ethionamide was concluded to be negative in the comet/MN combined assay. Busulfan did not induce DNA damage in any of the organs tested (liver and stomach) but it did induce a significant increase in MNPCEs in the bone marrow. Busulfan was concluded to be negative in the comet assay but positive in the MN assay.
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA. Electronic address: kamala.pant@bioreliance.com.
authors.forename: Kamala
authors.initials: K
authors.lastname: Pant
authors.affiliation: Retired from BioReliance by SAFC, USA.
authors.forename: Ljubica
authors.initials: L
authors.lastname: Krsmanovic
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA.
authors.forename: Shannon Wilson
authors.initials: SW
authors.lastname: Bruce
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA.
authors.forename: Tawney
authors.initials: T
authors.lastname: Kelley
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA.
authors.forename: Mirna
authors.initials: M
authors.lastname: Arevalo
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Atta-Safoh
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA.
authors.forename: Fekadu
authors.initials: F
authors.lastname: Debelie
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA.
authors.forename: Michelle L Klug
authors.initials: ML
authors.lastname: La Force
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA.
authors.forename: Sandra
authors.initials: S
authors.lastname: Springer
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA.
authors.forename: Jamie
authors.initials: J
authors.lastname: Sly
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA.
authors.forename: Madhav
authors.initials: M
authors.lastname: Paranjpe
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Lawlor
authors.affiliation: BioReliance by SAFC, Rockville, MD, USA; Marilyn Aardema Consulting, LLC, Fairfield, OH, USA.
authors.forename: Marilyn
authors.initials: M
authors.lastname: Aardema
mesh_terms: D000284:Administration, Oral; D000498:Allyl Compounds / Q000633:toxicity; D000818:Animals; D001853:Bone Marrow / Q000187:drug effects; D002066:Busulfan / Q000633:toxicity; D020552:Comet Assay / Q000379:methods*; D004249:DNA Damage / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005000:Ethionamide / Q000633:toxicity; D022781:Hepatocytes / Q000187:drug effects; D006843:Hydrocarbons, Chlorinated; D008099:Liver / Q000187:drug effects; D008297:Male; D015162:Micronucleus Tests / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D013270:Stomach / Q000187:drug effects
chemical_list: D000498:Allyl Compounds; D006843:Hydrocarbons, Chlorinated; C023891:1,3-dichloro-1-propene; D002066:Busulfan; D005000:Ethionamide
keywords: 1,3-Dichloropropene; Busulfan; Combination comet/MN assay; Ethionamide; In vivo comet assay; In vivo micronucleus (MN) assay; JaCVAM validation study