Butafenacil: A positive control for identifying anemia- and variegate porphyria-inducing chemicals. (2015)

• Record Type: Journal Article
• Authors: Leet, Jessica K.; Hipszer, Rachel A.; Volz, David C.
• Is Part Of: Toxicology reports. Volume 2(2015)
• Page Start: 976
• Page End: 983
• Publication Date: 2015
• Subjects: ai active ingredient -- DMSO dimethyl sulfoxide -- EM embryo media -- hpf hours post-fertilization -- MS-222 tricaine methanesulfonate -- PPOX protoporphyrinogen oxidase -- RO reverse osmosis; Butafenacil -- Zebrafish -- Anemia -- Porphyria -- Drug development; Toxicology -- Periodicals; Clinical toxicology -- Periodicals; Drug-Related Side Effects and Adverse Reactions; Hazardous Substances; Poisoning; Toxicology; Electronic journals; Periodicals; Periodicals; 571.9505
• DOI: 10.1016/j.toxrep.2015.07.006
• Languages: English
• ISSNs: 2214-7500

Abstract

Highlights: Butafenacil-induced anemia occurs in the presence or absence of light. Butafenacil-induced protoporphyrin accumulation only occurs in the presence of light. Embryonic zebrafish are not susceptible to butafenacil exposure following completion of pharyngula. Zebrafish embryos require >24 h to eliminate and recover from protoporphyrin accumulation following exposure to butafenacil during pharyngula. Abstract: Butafenacil is an herbicide that inhibits protoporphyrinogen oxidase (PPOX), an enzyme that catalyzes oxidation of protoporphyrinogen IX to protoporphyrin IX during chlorophyll and heme biosynthesis. Based on a high-content screen, we previously identified butafenacil as a potent inducer of anemia in zebrafish embryos. Therefore, the objective of this study was to begin investigating the utility of butafenacil as a positive control for identifying anemia- and variegate porphyria-inducing chemicals. Static exposure to butafenacil from 5 to 72 h post-fertilization (hpf) in glass beakers resulted in a concentration-dependent decrease in arterial circulation at low micromolar concentrations. At 72 hpf, the magnitude of butafenacil-induced anemia was similar when embryos were exposed in the presence or absence of light, whereas protoporphyrin accumulation and acute toxicity were significantly lower or absent when embryos were exposed under dark conditions. To identify sensitive developmental windows, we treated embryos to butafenacil from 5, 10, 24, or 48 hpf to 72 hpf in the presence of light, and found that anemia and protoporphyrin accumulation were present at 72 hpf following initiation of exposure at 5 and 10 hpf. On the contrary, protoporphyrin accumulation – but not anemia – was present following initiation of exposure at 24 hpf. Lastly, protoporphyrin accumulation at 72 hpf after exposure from 24 to 48 hpf suggests that protoporphyrin was not eliminated over a 24-h recovery period. Collectively, our data suggests that butafenacil may be a reliable positive control for identifying anemia- and variegate porphyria-inducing chemicals.