Blood biomarkers of common toad Rhinella arenarum following chlorpyrifos dermal exposure

Abstract

Chlorpyrifos (CPF) is a broad spectrum pesticide commonly used for insect control, has great affinity for lipids and is thus a potential for bioaccumulation in aquatic organisms. The aim of this study was to evaluate the toxicity of CPF using the common toad Rhinella arenarum via dermal uptake in plastic bucket to simulate their natural exposition in ponds. R. arenarum toads were exposed individually to solutions containing a nominal concentration of a commercial formulation of CPF insecticide (5 and 10 mg/L). Different enzyme biomarkers (BChE: butyrylcholinesterase, CbE: carboxylesterase, and CAT: catalase) were measured in blood tissue after exposition. The capacity of pyridine-2-aldoxime methochloride (2-PAM) to reverse OP-inhibited plasma BChE and the ratio of heterophils and lymphocytes (H/L) as hematological indicators of stress were also determined. The normal values of plasma B-sterases (BChE and CbE) were highly inhibited (until ≈ 70%) in toads 48 h after exposure to CPF. The results indicate that 2-PAM produced BChE reactivation as well. The activity of CAT was also inducted for dermal exposure at more than double of that in the control toads (CPF; 5 mg/L). H/L ratios did not reveal a significantly increased stress. The study suggests that CPF via dermal uptake induced neurotoxicity and oxidative stress in the common toad R. areanum. Thus, some blood biomarkers employed in our study (i.e. BChE, CbE, 2-PAM, and CAT) might be used as predictors in health and ecological risk assessment of amphibian populations exposed to CPF.

First evaluation of novel potential synergistic effects of glyphosate and arsenic mixture on Rhinella arenarum (Anura: Bufonidae) tadpoles

“…R. arenarum has a wide-ranging geographic distribution and abundance in the Neotropical region (Argentina, Bolivia, Brazil, and Uruguay) and it is also cited as “not threatened” in the Red List of amphibians of Argentina (Vaira et al., 2012). R. arenarum was reported as one of the most sensitive amphibian species for toxicological tests due to its high sensitivity to water pollution (Lajmanovich et al., 2018). The tadpoles were acclimated under laboratory conditions during 48 h at 12-h light/dark cycle in flasks (with dechlorinated tap water, DTW, pH 7.4 ± 0.05; conductivity, 165 ± 12.5 μmhos/cm; dissolved oxygen concentration, 6.5 ± 1.5 mg/L; hardness, 52.5 mg/L of CaCO 3 at 22 ± 2 °C).…”

Multiple Level Effects of Imazethapyr on Leptodactylus latinasus (Anura) Adult Frogs

“…Particularly, as mentioned in the introduction in other groups of organisms, few laboratory studies have evaluated adverse biological effects by IMZT and less in realistic exposure routes in juvenile and adult anurans, some examples are Rana esculenta (Quaranta et al, 2009), Sclerophrys regularis (Ezemonye and Tongo, 2010), Rana temporaria (Leiva-Presa and Munro Jenssen, 2006; Brühl et al, 2013), Rana pipiens (Selcer and Verbanic, 2014; Abercrombie et al, 2020), Acris crepitans, Gastrophryne carolinensis and Hyla versicolor (Van Meter et al, 2014), Hyla gratiosa and Hyla cinerea (Van Meter et al, 2014; Van Meter et al, 2015), Lithobates sphenocephala and Anaxyrus fowleri (Van Meter et al, 2014; Glinski et al, 2018), Lithobates clamitans (Edge et al, 2011; Van Meter et al, 2018), Anaxyrus americanus (Van Meter et al, 2015; Abercrombie et al, 2020). However, studies in Neotropical anurans affected by environmental stressors using various biomarkers at different organization levels are scarce and using other species such as Boana pulchella(Brodeur et al, 2011;Brodeur et al, 2012) and Rhinella arenarum(Castillo et al, 1991;Castillo et al, 2005;Lajmanovich et al, 2018). At this point, this is the rst laboratory work evaluating and integrating the effects of pesticidas at multiple biological scales in adults bioindicator species from agricultural environments and to be applied as early detection tools.…”

The impact of chemical pollution across major life transitions: a meta-analysis on oxidative stress in amphibians

“…After assessing for inclusion (Figure S1), we extracted 2,012 effect sizes from 86 studies (Acquaroni et al, 2021; Anguiano et al, 2001; Attademo et al, 2016; Awadalla et al, 2019; Barreto et al, 2020; Bhuyan et al, 2020; Burraco and Gomez-Mestre, 2016; Carvalho et al, 2020; Chai et al, 2017; Cheng et al, 2017; Cheron et al, 2022; Costa et al, 2008; Czarniewska et al, 2003; da Silva et al, 2021; David et al, 2012; De Lima Coltro et al, 2017; Dornelles and Oliveira, 2016; Ejilibe et al, 2018; Ezemonye and Tongo, 2010; Falfushynska et al, 2015; Falfushynska et al, 2017; Ferrari et al, 2008; Ferrari et al, 2009; Ferrari et al, 2011; Freitas et al, 2017; Gillardin et al, 2009; Huang et al, 2007; Isnas et al, 2012; Jiang et al, 2019; Jones et al, 2010; Kanter and Celik, 2012; Kostaropoulos et al, 2005; Lajmanovich et al, 2018b; Lajmanovich et al, 2018a; Lajmanovich et al, 2022; Li et al, 2017; Li et al, 2018a; Li et al, 2018b; Liendro et al, 2015; Liu et al, 2006; Liu et al, 2021; Loumbourdis, 2006; Lu et al, 2021; Mardirosian et al, 2015; Marques et al, 2013; Martins et al, 2017; Melvin, 2016; Mussi and Calcaterra, 2010; Naab et al, 2001; Nascimento et al, 2021; Nasia et al, 2018; Özkol et al, 2012; Pal et al, 2018; Papadimitriou and Loumbourdis, 2002; Peltzer et al, 2019; Radovanović et al, 2017; Radovanović et al, 2021; Rosenbaum et al, 2012; Rutkoski et al, 2020; Rutkoski et al, 2021; Saad et al, 2022; Salvaterra et al, 2013; Saria et al, 2014; Shi et al, 2018; Sotomayor et al, 2015; Svartz et al, 2020; Tang et al, 2018; Trachantong et al, 2017;…”