Publications by authors named "Natani Macagnan"

7 Publications

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Genotoxic effects of glyphosate on Physalaemus tadpoles.

Environ Toxicol Pharmacol 2021 Jan 17;81:103516. Epub 2020 Oct 17.

Laboratory of Ecology and Conservation, Federal University of Fronteira Sul, Erechim Campus, Brazil, ERS 135 - Km 72, nº 200, Erechim, RS, Brazil. Electronic address:

Genotoxicity studies have revealed that pesticides bind to genetic material in non-target vertebrates, thereby impairing the genetic integrity of these animals. The main objective of this study was to determine the genotoxic damage in erythrocytes of two native South American amphibian Physalaemus cuvieri and Physalaemus gracilis, both species exposed to a glyphosate-based herbicide. We evaluated the presence of micronuclei (MN) and erythrocyte nuclear abnormalities (ENA) as biomarkers for potential genotoxic compounds. Tadpoles were exposed to doses permitted by Brazilian legislation and concentrations found naturally in Brazilian and Argentinian waters (500, 700 and 1000 μg/L). Glyphosate-based herbicide caused micronuclei formation and several types of erythrocyte nuclear abnormalities in both Physalaemus species. The total frequency of MN and ENA demonstrated the occurrence of cell damage at all tested concentrations. Glyphosate herbicide can be considered a genotoxic that may impact the genetic integrity of native populations of P. cuvieri and P. gracilis.
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http://dx.doi.org/10.1016/j.etap.2020.103516DOI Listing
January 2021

Cypermethrin- and fipronil-based insecticides cause biochemical changes in Physalaemus gracilis tadpoles.

Environ Sci Pollut Res Int 2021 Jan 17;28(4):4377-4387. Epub 2020 Sep 17.

Ecology and Conservation Laboratory, Federal University of Fronteira Sul, Erechim Campus, RS 135 - Km 72, no 200, Erechim, RS, 99.700-000, Brazil.

Insecticides used for agricultural pest control, as cypermethrin-based insecticide (CBI) and fipronil-based insecticide (FBI), are constant threats to non-target aquatic organisms. This study aimed to investigate the effect of different concentrations of cypermethrin and fipronil on neurotoxicity and oxidative stress in Physalaemus gracilis. Physalaemus gracilis tadpoles were exposed to five insecticide concentrations and a control treatment, with six replicates. During the experimental period, the tadpole mortality rate was evaluated and after 168 h, the neurotoxic enzyme activity and metabolite quantification related to the antioxidant system were measured. Tadpoles reduced acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities when exposed to 20 μg L CBI and at all FBI concentrations, respectively. Glutathione S-transferase (GST) and superoxide dismutase (SOD) activities showed an increase from concentrations of 6 μg L and 20 μg L of CBI, respectively. After exposure of P. gracilis tadpoles to FBI, inhibitions of AChE and BChE were observed at the highest concentrations evaluated (500 and 1500 μg L). SOD activity decreased from 50 μg L of FBI; however, catalase (CAT) and GST activities and carbonyl protein levels increased, regardless of the evaluated dose. We observed that both insecticides promoted oxidative stress and neurotoxic effects in P. gracilis tadpoles. These results suggest that biochemical biomarkers can be used for monitoring toxicity insecticides for the purpose of preservation of P. gracilis.
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http://dx.doi.org/10.1007/s11356-020-10798-wDOI Listing
January 2021

Can environmental concentrations of glyphosate affect survival and cause malformation in amphibians? Effects from a glyphosate-based herbicide on Physalaemus cuvieri and P. gracilis (Anura: Leptodactylidae).

Environ Sci Pollut Res Int 2020 Jun 21;27(18):22619-22630. Epub 2020 Apr 21.

Laboratory of Ecology and Conservation, Federal University of Fronteira Sul, Erechim Campus, ERS 135 - Km 72, n°200, Erechim, RS, Brazil.

Herbicides are the most common agrochemicals used in crops. Among them, glyphosate is the most widely applied in the world. Herbicides, especially organophosphates, have been shown to be hazardous to non-target species, including amphibians. The present study evaluated the acute and chronic effects of glyphosate-based herbicide (GBH), Roundup original® DI on tadpoles from two South American native species, Physalaemus cuvieri and P. gracilis. Spawnings were collected in the natural environment and maintained in the laboratory under controlled conditions. Acute and chronic toxicology trials began at stage 25 of Gosner (Herpetological 16:183-190, 1960). In an acute toxicity assay, seven GBH concentrations between 100 and 4500 μg a.e./L were tested over 96 h. For the chronic trials, tadpoles were subjected to both doses allowed by Brazilian legislation and to concentrations found in natural environment waters from Brazil and Argentina, between 65 and 1000 μg a.e/L over 14 days. Glyphosate had lethal effects on both studied species. Tadpoles showed shorter lengths and lower masses; that is, those that survived suffered chronic effects on growth and weight. The GBH maximum acceptable toxicant concentration for mortality and malformation was lower than the allowed level for Brazilian waters. The GBH tested in this study presented a high environmental and acute risk for the two studied species.
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http://dx.doi.org/10.1007/s11356-020-08869-zDOI Listing
June 2020

Morphological and biochemical traits and mortality in Physalaemus gracilis (Anura: Leptodactylidae) tadpoles exposed to the insecticide chlorpyrifos.

Chemosphere 2020 Jul 10;250:126162. Epub 2020 Feb 10.

Ecology and Conservation Laboratory, Federal University of Fronteira Sul, Erechim Campus, RS 135 - Km 72, No 200, 99700-000, Erechim, RS, Brazil. Electronic address:

Organophosphate insecticides such as chlorpyrifos are commonly detected in surface waters around the world, where they are highly toxic to many organisms. The frog Physalaemus gracilis uses water sources located in open fields as reproductive sites, where it is exposed to insecticides. The study aimed to evaluate the lethal and sublethal effect of a commercial chlorpyrifos formulation on P. gracilis tadpoles (Anura: Leptodactylidae). In acute toxicity tests, five chlorpyrifos concentrations between 750 and 2,000 μg L were tested. Chronic toxicity, swimming activity, morphological and enzymatic changes, as well as levels of non-protein thiols (NPSH), carbonyl proteins and lipid peroxidation were evaluated at five insecticide concentrations between 11 and 500 μg L. The highest mortality rate of P. gracilis tadpoles occurred at 24 and 48 h, with an LC of 893.59 μg L. At all chlorpyrifos concentrations, tadpoles displayed reduced mobility and spasms. Morphological anomalies were observed in the mouth and intestine, especially at the highest concentrations used. Acetylcholinesterase activity decreased at 250 and 500 μg L, catalase activity increased at all concentrations, and superoxide dismutase and glutathione S-transferase increased from 90 μg L to 30 μg L, respectively. We also observed increases in NPSH levels at chlorpyrifos concentration starting at 30 μg L and increases in carbonyl proteins from 90 μg L of pesticide. Taken together, these data suggest that the insecticide chlorpyrifos presents acute and chronic risks for P. gracilis, causing neurotoxic effects and oxidative damage, culminating in high risk for this species.
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http://dx.doi.org/10.1016/j.chemosphere.2020.126162DOI Listing
July 2020

Toxic effects of pyrethroids in tadpoles of Physalaemus gracilis (Anura: Leptodactylidae).

Ecotoxicology 2019 Nov 5;28(9):1105-1114. Epub 2019 Oct 5.

Laboratory of Ecology and Conservation, Federal University of Fronteira Sul, Erechim Campus, Brazil.

Pyrethroid insecticides are one of the most commonly used pesticide groups, but these compounds have brought risks to non-target species, such as amphibians. This study evaluated the toxicological effects (mortality, swimming activity and oral morphology) caused to a South American species of anuran amphibian, Physalaemus gracilis, exposed to the pyrethroids cypermethrin and deltamethrin. Total spawnings of this anuran were collected in the natural environment and transported to the laboratory where they were kept under controlled conditions. Chronic assays were defined between 0.1 and 0.01 mg L of cypermethrin, and 0.009 and 0.001 mg L of deltamethrin. For cypermethrin, a further chronic toxicity test was performed at 0.05 and 2.0 mg L, with hatchlings at stages S.20-S.25. Cypermethrin and deltamethrin were lethal enough to kill over 70% of exposed tadpoles in 1 week at concentrations that can be found in nature (0.01-0.1 mg L). The exposure effects also influenced swimming activity and caused changes in oral morphology, which would make it difficult for the animals to survive in their natural habitat. Both pyrethroids presented a risk for P. gracilis, so they should be re-evaluated for non-target wild species.
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http://dx.doi.org/10.1007/s10646-019-02115-0DOI Listing
November 2019

Lethal and Sublethal Effects of the Herbicide Atrazine in the Early Stages of Development of Physalaemus gracilis (Anura: Leptodactylidae).

Arch Environ Contam Toxicol 2018 May 6;74(4):587-593. Epub 2018 Jan 6.

Ecology and Conservation Laboratory, Federal University of Fronteira Sul, Erechim Campus, ERS 135 - Km 72, no. 200, Erechim, RS, Brazil.

Water sources used as reproductive sites by crying frog, Physalaemus gracilis, are extensively associated with agroecosystems in which the herbicide atrazine is employed. To evaluate the lethal and sublethal effects of atrazine commercial formulation, acute and chronic toxicity tests were performed in the embryonic phase and the beginning of the larval phase of P. gracilis. Tests were started on stage 19 of Gosner (Herpetologica 16:183-190, 1960) and performed in 24-well cell culture plates. Acute tests had a duration of 96 h with embryo mortality monitoring every 24 h. Chronic assays contemplated the transition from the embryonic to larval stages and lasted 168 h. Every 24 h the embryos/larvae were observed for mortality, mobility, and malformations. The LC50 of atrazine determined for P. gracilis embryos was 229.34 mg L. The sublethal concentrations did not affect the development of the larvae but were observed effects on mobility and malformations, such as spasmodic contractions, reduced mobility, malformations in mouth and intestine, and edema arising. From 1 mg L atrazine, the exposed larvae began to have changes in mobility and malformations. The atrazine commercial formulation has caused early life effects of P. gracilis that may compromise the survival of this species but at higher concentrations than recorded in the environment, so P. gracilis can be considered tolerant to this herbicide at environmentally relevant concentrations.
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http://dx.doi.org/10.1007/s00244-017-0501-yDOI Listing
May 2018

Toxicity of cypermethrin and deltamethrin insecticides on embryos and larvae of Physalaemus gracilis (Anura: Leptodactylidae).

Environ Sci Pollut Res Int 2017 Sep 16;24(25):20699-20704. Epub 2017 Jul 16.

Ecology and Conservation Laboratory, Federal University of Fronteira Sul, Erechim Campus, ERS 135 - Km 72, no 200, Erechim, RS, Brazil.

It is important to establish the toxicity pesticides against non-target species, especially those pesticides used in commercial formulations. Pyrethroid insecticides are widely used in agriculture despite their toxicity to aquatic animals. In this study, we determine the toxicity of commercial formulation of two pyrethroid insecticides, cypermethrin and deltamethrin, in two life stages of Physalaemus gracilis, a frog that breeds in agricultural ecosystems and has potential contact with pyrethroid pesticides. The acute toxicity test (96 h) was carried out with embryos of stage 17:18 and larvae of stages 24:25. Embryos were more resistant to both pesticides than larvae. In embryo mobility assays, we found that both pesticides caused spasmodic contractions, suggestive of neurological effects. In acute toxicity assays, we found that P. gracilis is more resistant to these insecticides than other studied species.
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http://dx.doi.org/10.1007/s11356-017-9727-5DOI Listing
September 2017