BPA toxicity during development of zebrafish embryo

Abstract

Bisphenol A (BPA) is a monomer used in the production of polycarbonate, a polymer commonly found in plastics, epoxy resins and thermal papers. The presence of BPA in food, water, air and dust has been of great concern in recent years not only due to environmental and ecological issues but also because of its supposed risk to public health related to its mutagenic and carcinogenic potential. In this study we evaluated the toxicity of bisphenol A in zebrafish embryos (Danio rerio) and determined the 50% lethal concentration (LC50) of this chemical. BPA was used at concentrations ranging from 1 μM to 100 μM in E3 medium/0.5% dimethylsulfoxide (DMSO) from previously prepared stock solutions in 100% DMSO. Controls included embryos exposed only to E3 medium or supplemented with 0.5% DMSO. Camptothecin (CPT), a known inhibitor of cell proliferation was used as positive control at a concentration of 0.001 μM in E3 medium/0.5% DMSO. Adults zebrafish were placed for breeding a day before the experimental set up, then, viable embryos were collected and selected for use. Experiments were carried out in triplicates, according to specifications from Organization for Economic Cooperation and Development (OECD). One embryo/well (25 embryos per concentration) was distributed in 96 well microplates in presence or absence of the chemicals. The plates were kept in BOD incubators with a controlled temperature of 28.5 ºC and with photoperiod of 14 h light:10 h dark. After 24h, 48h, 72h and 96h exposure, the exposed embryos were evaluated according to the following parameters: mortality, coagulation, rate of heartbeat, hatching and presence of morphological abnormalities. Photography was obtained by photomicroscopy. Apoptosis was evaluated by DNA ladder assay. DNA was extracted by phenol:chloroform method and analyzed by 2% agarose gel electrophoresis. DNA fragments were visualized after ethidium bromide staining in ultraviolet transilluminator. The LC50 determined for BPA was 70 μM after 24 hours, 72 μM after 48 hours, 47 μM after 72 hours and 31 μM after 96 hours exposure. BPA induced morphological and physiological alterations such as yolk sac and pericardial edema, hatching delay or inhibition, spine deformation, decreasing in heartbeat rate and mortality. In conclusion, this study demonstrated that BPA induced marked malformations in zebrafish embryos at concentrations above 25 μM corroborating the current concerns related to the widespread presence of BPA in the air, food and water used by humans as well as in the bodily fluids and tissues.

Bisphenol A Exposure Induces Sensory Processing Deficits in Larval Zebrafish during Neurodevelopment

“…A recent report by Scopel et al (2021) investigated the effect of 25 μ m BPA on mortality, deformity, and hatching in larval zebrafish. Because Scopel et al (2021) only exposed zebrafish to 25 μ m BPA for 3 d, we investigated the consequences of a 5-d exposure of larvae to 25 μ m BPA.…”

“…A recent report by Scopel et al (2021) investigated the effect of 25 μ m BPA on mortality, deformity, and hatching in larval zebrafish. Because Scopel et al (2021) only exposed zebrafish to 25 μ m BPA for 3 d, we investigated the consequences of a 5-d exposure of larvae to 25 μ m BPA. As shown in Figure 4 A , larvae exposed to 25 μ m BPA did not exhibit a statistically significant increase in mortality (BPA group = 3.33 ± 3.33) compared with the vehicle control group (DMSO group = 0.00 ± 0.00).…”

“…It has been found that exposure to relatively high concentrations of BPA early in the zebrafish life cycle increases mortality and deformity, and delays hatching. Interestingly, despite general agreement regarding the adverse effects of high levels of BPA on mortality, body shape, and time of hatching, the reported threshold concentration of BPA for producing these effects varies greatly ( Lam et al, 2011 ; Saili et al, 2012 ; Tse et al, 2013 ; Wang et al, 2013 ; Martínez et al, 2018 ; Olsvik et al, 2019 ; Coumailleau et al, 2020 ; Gyimah et al, 2021 ; Huang et al, 2021 ; Scopel et al, 2021 ; Sundarraj et al, 2021 ; Wu et al, 2021 ). Furthermore, some studies have found that BPA exposure modifies locomotion in zebrafish, whereas others have not ( Saili et al, 2012 ; Wang et al, 2013 ; Kinch et al, 2015 ; Fraser et al, 2017 ; Olsvik et al, 2019 ; Coumailleau et al, 2020 ; Gyimah et al, 2021 ; Wu et al, 2021 ).…”

Bisphenol A Interferes with Redox Balance and the Nrf2 Signaling Pathway in Xenopus tropicalis during Embryonic Development

“…In this study, increased BPA exposure increased the deformity and mortality rates of X. tropicalis embryos. Several studies have found that exposure to high concentrations of BPA induces rapid and high mortality in X. laevis , zebrafish embryos, and Artemia nauplii [ 30 , 31 , 32 ]. However, our results show that the mortality rate of 100 μmol/L BPA treatment was 16.33% ± 2.08%.…”

Bisphenol A Removal Using Visible Light Driven Cu2O/PVDF Photocatalytic Dual Layer Hollow Fiber Membrane

“…Currently, a study reported that allowed concentration of BPA presence in water by international regulation is 0.05 ppm [8]. The lethal concentrations 50 (LC50) for BPA are 31 µM for 96 h, 47 µM for 72 h, 72 µM for 48 h and 70 µM for 24 h exposure [9]. The terminal half-life for BPA in the body is about 17.6 ± 7.69 h [10].…”