Predicted and measured acute toxicity and developmental abnormalities in zebrafish embryos produced by exposure to individual aromatic acids

Abstract

Petroleum acids, often called 'Naphthenic Acids' (NA), enter the environment in complex mixtures from numerous sources. These include from Produced and Process-Affected waters discharged from some oil industry activities, and from the environmental weathering of spilled crude oil hydrocarbons. Here, we test the hypothesis that individual NA within the complex mixtures can induce developmental abnormalities in fish, by screening a range of individual acids, with known chemical structures. Sixteen aromatic NA were tested using a Thamnocephalus platyrus (beavertail fairyshrimp) assay, to establish acute toxicity. Toxicities ranged from 568 to 8 μM, with the methylbiphenyl acid, 4-(p-tolyl)benzoic acid, most toxic. Next, five of the most toxic monoacids and for comparison, a diacid, were assayed using Danio rerio (zebrafish) embryos to test for lethality and developmental abnormalities. The toxicities were also predicted using Admet predictor™ software. Exposure to the five monoacids produced deformities in zebrafish embryos in a dose-dependent manner. Thus, exposure to 4-(p-tolyl)benzoic acid produced abnormalities in >90% of the embryos at concentrations of <1 μM; exposure to dehydroabietic acid caused pericardial edema and stunted growth in 100% of the embryos at 6 μM and exposure to pyrene-1-carboxylic acid caused 80% of embryos to be affected at 3 μM. The findings of this preliminary study therefore suggest that some aromatic acids are targets for more detailed mechanistic studies of mode of action. The results should help to focus on those NA which may be important for monitoring in oil industry wastewaters and polluted environmental samples.

An Efficient Strategy for the Glycosylation of Total Bufadienolides in Venenum Bufonis

“…The 96-well plate was incubated at 28.5 °C. After 72 h postfertilization exposure, the mortality rate was calculated and compared to the positive control. , …”

“…After 72 h postfertilization exposure, the mortality rate was calculated and compared to the positive control. 41,42 ■ ASSOCIATED CONTENT * S Supporting Information…”

Changes in chemical composition and copepod toxicity during petroleum photooxidation

“…22,28 Additionally, oxygenated aliphatic compounds present in tar sand processed water have also been found to be associated with ecotoxicity. [29][30][31][32][33][34] Together, these studies suggest that the process of photooxidation of oil produces a complex mixture of photoproducts that influences the toxicity of the oil residue. However, there are still knowledge gaps regarding the importance of oil photoproducts to the overall oil toxicity.…”

Changes in Chemical Composition and Copepod Toxicity during Petroleum Photo-oxidation

“…While PAHs are often considered the main contributors of toxicity in crude oil, − oxygenated hydrocarbons produced by oil photo-oxidation can be significant contributors to toxicity in irradiated oil. − Among the potential photoproducts that are responsible for the observed effects, oxygenated PAHs can show increased toxicity compared to their parent compounds. , Additionally, oxygenated aliphatic compounds present in tar sand-processed water have also been found to be associated with ecotoxicity. − In contrast, other studies found that oil photo-oxidation was not associated with a significant increase in toxicity. ,− …”