Evaluation of the potential teratogenic and toxic effect of the herbicide 2,4-D (DMA (R) 806) in bullfrog embryos and tadpoles (Lithobates catesbeianus)

Author(s)

Viriato, Cristina ^{[1, 2]} ; Franca, Fernanda Menezes ^[1] ; Santos, Diego Sales ^[1] ; Marcantonio, Adriana Sacioto ^[3] ; Badaro-Pedroso, Cintia ^[1] ; Ferreira, Claudia Maris ^[1]

Affiliation

^[1] Fisheries Inst APTA SAA, 455 Francisco Matarazzo Ave, BR-05001900 Sao Paulo, SP - Brazil

^[2] Sao Paulo State Univ UNESP, Dept Biotechnol, Inst Biosci Botucatu, Dist Rubiao Jr S-N, Caixa Postal 510, BR-18618970 Botucatu, SP - Brazil

^[3] APTA Reg APTA SAA, 1920 Prof Manoel Cesar Ribeiro Ave, BR-12411010 Pindamonhangaba, SP - Brazil

• Document type: Journal article
• Source: Chemosphere; v. 266, MAR 2021.
• Web of Science Citations: 2

Abstract

The objective of this work was to evaluate the potential teratogenic and toxic effect of the herbicide 2,4-D (DMA (R) 806) on bullfrog embryos and tadpoles (Lithobates catesbeianus). We used the FETAX (Frog Embryo Teratogenesis Assay Xenopus) assay for embryos, and for tadpoles, we used acute (96 h) and chronic (49 days) toxicity tests and evaluated aspects of healthiness, hematology, and histopathology. The LC50-144h (Median Lethal Concentration), EC50-144h (Median Effective Concentration), MCIG (Minimum Concentration to Inhibit Growth) and TI (Teratogenic Index) for embryos were 792 mg/L, 593 mg/L, 150 mg/L of 2,4-D (DMA) and 1.34, respectively. For tadpoles, the LC50-96h was 700 mg/L of 2,4-D (DMA) and chronic test indicated an inflammatory process and erythrocytosis (with possible polycythemia), with consequent reduction of the spleen. This demonstrates physiological stress probably due to dehydration, which can be proven by the gill tufts widening intercellular space and gill tuft fusions. We also found injuries to the kidneys and skin of the animals even in the lowest concentration tested. Our results indicated that this pesticide is minimally teratogenic and has a low toxicity on L. catesbeianus embryos and tadpoles, but it can inhibit embryo growth in concentrations lower than those tested in this study. We hypothesized that the herbicide 2,4-D (DMA (R) 806) may be a respiratory allergen for L. catesbeianus tadpoles and recommend precautionary measures for prolonged exposure of aquatic organisms to this pesticide. (C) 2020 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 18/26153-1 - Evaluation of the toxicity of 2,4-D (DMA) herbicide and its potential teratogenic effect on bullfrog embryos (Lithobates catesbeianus)
• Grantee: Cristina Viriato de Freitas
• Support Opportunities: Scholarships in Brazil - Master