In vivo genotoxicity and cytotoxicity assessment of a novel quinoxalinone with trichomonacide activity

The compound VAM2-6 (1-methyl-7-nitro-4-(5-(piperidin-1-yl)pentyl)-3,4-dihydroquinoxalin-2(1H)-one) has previously been shown to have an in vitro efficacy of 100% at a concentration of 100μgml^-1 against Trichomonas vaginalis, a protozoon parasite that causes the sexually transmitted disease trichomoniasis. Because VAM2-6 is a quinoxaline derivative and given the lack of studies on the genotoxic activity of this compound, the present study was undertaken to evaluate its ability to induce DNA damage in the peripheral blood of mice using single-cell gel electrophoresis (SCGE or comet assay) and the micronucleus (MN) assay. Cell viability was assessed using a fluorochrome-mediated viability test. The compound was tested on CD1 mice at 60, 40 and 10mgkg^-1 body weight administrated intraperitoneal (i.p.) in a single dose. Peripheral blood samples were collected 24 and 48h after treatment. N-Ethyl-N-nitrosourea (ENU) was used as a positive control for the comet and micronucleus assays. The results showed that i.p. VAM2-6 induced single-strand DNA breaks and increased the average number of micronuclei in the treated mice in a dose-dependent manner at 60, 40 and 10mgkg^-1. Cell viability decreased at 24h but recovered at 48h for all three evaluated doses. Therefore, the chemical structure of VAM2-6 should be modified to reduce its genotoxic potential.