Assessment of the in vivo genotoxicity of isomers of dinitrotoluene using the alkaline Comet and peripheral blood micronucleus assays

Abstract

a b s t r a c t Dinitrotoluene (DNT) is a nitroaromatic explosive that exists as six isomers; two major isomers (2,4-and 2,6-DNT) and four minor isomers (2,2,3,and 3,. DNT has been found in soil, surface water, and groundwater near ammunition production plants. The major isomers of DNT are classified as "likely to cause cancer in humans." In vitro studies have provided conflicting data regarding the genotoxicity of the minor isomers. Studies indicate that metabolism in the gut and liver are necessary to convert DNT to genotoxic compounds. As such, in the present study the genotoxicity of isomers of DNT was assessed using two in vivo genotoxicity assays. The Comet assay was used to detect DNA damage in liver cells from male Sprague-Dawley rats following oral exposure (14-day) to individual isomers of DNT. The micronucleus assay was conducted using flow cytometric analysis to detect chromosomal damage in peripheral blood. Treatment with 2,3-, 3,4-, 2,4-, 2,5-and 3,5-DNT did not induce DNA damage in liver cells or increase the frequency of micronucleated reticulocytes (MN-RET) in peripheral blood at the doses tested. Treatment with 2,6-DNT induced DNA damage in liver tissue at all doses tested, but did not increase the frequency of micronucleated reticulocytes (MN-RET) in peripheral blood. Thus, 2,4-DNT and the minor isomers were not genotoxic under these test conditions, while 2,6-DNT was genotoxic in the target tissue, the liver. These results support previous research which indicated that the hepatocarcinogenicity of technical grade DNT (TG-DNT) could be attributed to the 2,6-DNT isomer.Published by Elsevier B.V.

Ecological Risk Assessment of Munitions Compounds on Coral and Coral Reef Health

“…This nitroaromatic compound can be found as a soil contaminant from spills during manufacturing, landfill seepages, and leaking munitions wastes. Although it is a minor isomer (estimated at 1.54%) of Technical grade dinitrotoluene (Lent et al 2012), it has been recognized as more toxic than its major isomers (2,4-DNT and 2,6-DNT) or the parent compound TNT, particularly for some freshwater organisms (fish, arthropods and algae). This compound has a solubility of 99 mg/L in 33.…”

Evaluation of the Genotoxic and Antigenotoxic Effects of Andiroba (Carapa guianensis Aublet) Oil and Nanoemulsion on Swiss Mice

“…Because the reduction was much more significant in the AO + DOX group (89% reduction of MNPCEs and 45% of MNNCEs) than the AN + DOX group (62% reduction of MNPCEs and 42% of MNNCEs) and because the AO was diluted with corn oil, the antimutagenic effect may have been enhanced by the joint action of the two oils. However, many studies have used corn oil as a dilution vehicle to test vegetable oils because corn oil is a good medium for this purpose [32][33][34][35][36][37]. Thus, more accurate research concerning the effect of corn oil in combination with other vegetable oils is needed.…”

Nicotiana tabacum-associated bioengineered Pseudomonas putida can enhance rhizoremediation of soil containing 2,4-dinitrotoluene

“…2,4-DNT, is a typical soil contaminant at ammunition manufacturing sites, derived mainly from the synthesis of the explosive 2,4,6-trinitrotoluene (TNT) but also from the production of polyurethane foams and dyes (Nishino et al 2000;Serrano-González et al 2018). This mutagenic and carcinogenic substance is listed on the Hazardous Air Pollutants List ruled by the U.S. Environmental Protection Agency (EPA) (Lent et al 2012;Xu and Jing 2012) and also on Resource Conservation and Recovery Act (RCRA) Toxicity Characteristic Leaching Procedure (TCLP) organics list. According to EPA (2006), soils and wastes that contain 2,4-DNT are classified as RCRA characteristic hazardous waste and a special treatment will be needed, if they produce leachate comprising 2,4-DNT equal or above the TCLP threshold concentration (0.13 mg/L).…”