Hexavalent chromium is cytotoxic and genotoxic to American alligator cells

Abstract

Metals are a common pollutant in the aquatic ecosystem. With global climate change, these levels are anticipated to rise as lower pH levels allow sediment bound metals to be released. The American alligator (Alligator mississippiensis) is an apex predator in the aquatic ecosystem and is considered a keystone species; as such it serves as a suitable monitor for localized pollution. One metal of increasing concern is hexavalent chromium (Cr(VI)). It is present in the aquatic environment and is a known human carcinogen and reproductive toxicant. We measured the cytotoxicity and genotoxicity of Cr(VI) in American alligator cells derived from scute tissue. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to alligator cells in a concentration-dependent manner. These data suggest that alligators may be used as a model for assessing the effects of environmental Cr(VI) contamination as well as for other metals of concern.

The comparative cytotoxicity and genotoxicity of hexavalent chromium in humans and sea turtles.

“…This result also demonstrates temporal-and species-specific differences in Cr ion uptake. The results also support previous studies showing different levels of Cr uptake between human cells and those of other species [5,6,7,58,59]. However, in some cases human cells internalize more Cr, and in others cells from wildlife species have higher levels of intracellular Cr.…”

“…This is contrary to results following lead chromate exposure which resulted in very similar levels of intracellular Cr ion concentrations in both leatherback and hawksbill sea turtle cells. Finally, a study that investigated soluble and particulate Cr(VI) in alligator cells found that they accumulated similar levels of intracellular Cr following particulate chromate exposure, but lower intracellular Cr ion concentrations following soluble chromate exposures [58]. Together, the results of this study show that Cr can enter leatherback sea turtle lung cells following exposure to chromate compounds.…”

“…Previous studies have shown that metals such as cobalt, nickel, and Cr can have varying toxic effects based on the solubility of the metals [5,6,16,17,58,59].…”

The cytotoxicity and genotoxicity of particulate and soluble hexavalent chromium in leatherback sea turtle lung cells

“…Cr(VI) is an established human carcinogen, reproductive toxicant, and genotoxicant in humans and laboratory animals that primarily targets the respiratory and reproductive systems (Holmes et al, 2008; Mancuso et al, 1997; Wise et al, 2011; Witmer et al, 1989; Witmer et al, 1991). Recently it has also been shown to be a concern for marine species including marine mammals and aquatic reptiles (Li Chen et al, 2009, Li Chen et al, 2012; Wise et al, 2009b; Wise et al, 2014; Wise et al, 2016; Young et al, 2015). We chose to evaluate Cr(VI) in leatherbacks to better understand how Cr(VI) leads to lung carcinogenesis as a part of a larger effort under a concept known as the One Environmental Health Approach.…”

Characterization of Penicillium oxalicum SL2 isolated from indoor air and its application to the removal of hexavalent chromium

“…In nature, Cr mainly exists as Cr(VI) and Cr(III) compounds [ 3 ], which differ in their mobility and toxicity [ 4 ]. Cr(VI) compounds are water soluble in the full pH range and are toxic to humans [ 5 , 6 ], animals [ 7 ], plants [ 8 ], and microorganisms [ 9 ], whereas Cr(III) compounds are less water soluble and serve as essential nutrients for energy metabolism [ 10 ]. Thus, reducing Cr(VI) to Cr(III) can minimize its harm to the environment and human health.…”