DNA single-strand breaks and cytotoxicity induced by sodium chromate(VI) in hydrogen peroxide-resistant cell lines

Unraveling the mechanism responsible for the contrasting tolerance of Synechocystis and Synechococcus to Cr(VI): Enzymatic and non-enzymatic antioxidants

“…Chinese hamster ovary (CHO) cells that produced 2-fold more catalase were more resistant to Cr(VI) induced cytotoxicity than cells producing normal levels of catalase (Sugiyama et al, 1993). Similarly, over-expression of SOD ameliorated the toxic effects of Cr(VI) in Drosophila melanogaster (Pragya et al, 2014).…”

DNA Single-Strand Breaks and Cytotoxicity Induced by Chromate(VI), Cadmium(II), and Mercury(II) in Hydrogen Peroxide-Resistant Cell Lines

“…For this reason, we also examined the formation of chromium(V) in both cell lines. The results showed the appearance of the chromium(V) ESR signal with a maximum peaks at g= 1.978 during the incubation of cells with Na2CrO4 and it was found that the level of this chromium(V) was about 2-fold lower in the resistant cells (12 …”

“…Previous studies have demonstrated that these metal compounds may cause adverse biologic effects, possibly through free radical species such as active oxygen, because active oxygen scavengers prevented metals-induced cellular injuries such as DNA breaks (4)(5)(6). With respect to chromium(VI), although active oxygen species have been reported to be generated during reduction of chromium(VI) to chromium(V) in vitro (3,(7)(8)(9)(10)(11), only one study examined the involvement of active oxygen species in chromium(VI)-induced genotoxicity and cytotoxicity in intact cells (6 It is unlikely that the observed metalresistance in CHOR cells was due to alterations of metal uptake, because there was no difference in the uptake of the metals in these cell lines (12). Since chromium(VI) enters cells and is then reduced to chromium(III), the formation of chromium(III) and other oxidation states, in particular chromium(V), is believed to play a role in some of the biological effects of chromium(VI) (1)(2)(3).…”

Human Erythrocytes Are Protected against Chromate-Induced Peroxidation

“…isolated rat hepatocytes (Ueno et al, 1988) and primary cultures of rat hepatocytes (Susa et al, 1996(Susa et al, , 1997a, as well as in intracellular organelles, namely, hepatic and brain mitochondria and microsomes of rats (Bagchi et al, , 1997. It was also reported that low concentrations of chromate cause pronounced and signi"cant cyto-and genotoxic e!ects in cells and culture cells (Susa et al, 1996(Susa et al, , 1997aCoogan et al, 1991;Sugiyama et al, 1986Sugiyama et al, , 1993. These discrepancies can be explained by the high chromium(VI) reducing capacity of RBCs, which greatly attenuates its toxicity and genotoxicity (De Flora et al, 1997), and to the high chromium binding ability of RBC low-molecularweight components, chie#y hemoglobin (Aaseth et al, 1982;Kiagawa et al, 1982;Connett and Wetterhahn, 1983;Wiegand et al, 1984Wiegand et al, , 1988Lewalter et al, 1985;Ottenwalder et al, 1988) a protein that is present only in RBCs.…”