Phenanthrene Bioaccumulation in the Nematode Caenorhabditis elegans

Abstract

The contribution of food to the bioaccumulation of xenobiotics and hence toxicity is still an ambiguous issue. It is becoming more and more evident that universal statements cannot be made, but that the relative contribution of food-associated xenobiotics in bioaccumulation depends on species, substance, and environmental conditions. Yet, small-sized benthic or soil animals such as nematodes have largely been disregarded so far. Bioaccumulation of the polycyclic aromatic hydrocarbon phenanthrene in the absence and presence of bacterial food was measured in the nematode Caenorhabditis elegans. Elimination of phenanthrene in the nematodes was biphasic, suggesting that there was a slowly exchanging pool within the nematodes or that biotransformation of phenanthrene took place. Even with food present, dissolved phenanthrene was still the major contributor to bioaccumulated compound in nematode tissues, whereas the diet only contributed about 9%. Toxicokinetic parameters in the treatment without food were different from the ones of the treatment with bacteria, possibly because nematodes depleted their lipid reserves during starvation.

Toxicity-based toxicokinetic/toxicodynamic assessment of bioaccumulation and nanotoxicity of zerovalent iron nanoparticles in <em>Caenorhabditis elegans</em>

“…37,75 However, it has been found that some of these physiological parameters do not have significant influence on sublethal endpoints, such as growth and reproduction, in worms. 75 It has been suggested that variations in any TBTK data set could be associated with biological variation, experimental, and analytical errors.…”

“…The mixed-toxicity effects of Cd and fluoranthene in C. elegans have been interpreted using an energy-based TBTK/TD model. 36 A two-compartmental TBTK modeling of phenanthrene in C. elegans has been performed, 37 indicating that waterborne exposure was the major route to bioaccumulated compound in the nematode tissues. A recent study also employed a TBTK/TD energybased model to describe the joint toxicity of uranium and Cd over growth and reproduction periods in C. elegans.…”

Contribution of Dietary Uptake to PAH Bioaccumulation in a Simplified Pelagic Food Chain: Modeling the Influences of Continuous vs Intermittent Feeding in Zooplankton and Fish

“…No major difference between BCF ss and BAF ss was expected when the food ingestion rate was at a low level, even if the freely dissolved concentrations were similar. This may also partly explain the variability of relative dietary uptake contribution to the previously reported bioaccumulation of PAHs in macroinvertebrates, especially in the filter feeders for which the contribution is mostly derived from only one food concentration. − …”

“…magna might not have the capacity to biotransform PAHs- d 10 and that the estimated k eg in bioaccumulation was mainly contributed by the excretion rate constant. In contrast to k eg , the elimination rate constant in the body except gut ( k eb ) in bioconcentration was higher than its counterpart in bioaccumulation, and this was plausibly caused by lipid loss under starvation …”

Caenorhabditis elegans as an emerging model system in environmental epigenetics

“…Similarly, although humans rapidly methylate inorganic arsenic after absorption and often have mixtures of parent chemical and metabolites in circulation, because C. elegans lacks an arsenic methyltransferase, we were able to isolate the effect of inorganic arsenic on mitochondrial function (Luz et al, ). Despite these differences, with expanded use of worms in environmental toxicology, worm toxicokinetics have been described for a growing list of pollutants, including nanoparticles (Yang, Lin and Liao, ), cisplatin (Crone, Aschner, Schwerdtle, Karst and Bornhorst, ), chlorpyrifos (Roh, Lee and Kwon, ), and phenanthrene (Spann, Goedkoop and Traunspurger, ). In addition to species‐specific differences, experimental culture conditions are an important consideration in molecular toxicology experiments in C. elegans .…”