Impact of butyl benzyl phthalate on development of the reproductive system of European pikeperch, Sander lucioperca (L.)

High concentrations of phthalates affect the early development of the sea urchin Paracentrotus lividus

The toxicity of three phthalates (PAEs) - butylbenzyl phthalate (BBP), diethyl phthalate (DEP), and di-(2-ethylhexyl) phthalate (DEHP) - was tested on the Mediterranean sea urchin Paracentrotus lividus. Fertilized eggs were exposed to environmental and high PAE concentrations for 72 h. The potential toxic effects on larval development and any morphological anomalies were then assessed to estimate PAEs impact. Environmental concentrations never affected development, while high concentrations induced toxic effects in larvae exposed to BBP (EC50: 2.9 ×103 µg/L) and DEHP (EC50: 3.72 ×103 µg/L). High concentrations caused skeletal anomalies, with a slight to moderate impact for DEP/DEHP and BBP, respectively. PAE toxicity was: BBP>DEHP>DEP. In conclusion, the three PAEs at environmental concentrations do not pose a risk to sea urchins. However, PAE concentrations should be further monitored in order not to constitute a concern to marine species, especially at their early developmental stages.

Butyl Benzyl Phthalate (BBP) disrupts neuromast development in embryonic zebrafish

Butyl benzyl phthalate (BBP) is found in common household and industrial products world-wide. Phthalates are not covalently bound to plastics and continuously leach into the soil, sediment and aquatic environments. The lateral line system of fish is a mechanosensory system composed of neuromasts essential for survival behaviors including rheotaxis, schooling and predator avoidance. Here, we investigated the developmental toxicity of BBP on the developing lateral line neuromasts in zebrafish. Embryos were treated at gastrula stage with BBP and analyzed by DASPEI staining at 4 days post fertilization. We find that BBP negatively affects neuromast development leading to loss of DASPEI signal in neuromasts in a concentration dependent manner.

Alleviative effect of quercetin against reproductive toxicity induced by chronic exposure to the mixture of phthalates in male rats

Phthalates (PEs) are widely used plasticizers in polymer products, and humans are increasingly exposed to them. This study was designed to investigate the alleviative effect of phytochemicals quercetin (Que) against male reproductive toxicity caused by the mixture of three commonly used PEs (MPEs), and further to explore the underlying mechanism. Forty-eight male SD rats were randomly and evenly divided into control group, Que group, MPEs group and MPEs+Que group (n = 12); The oral exposure doses of MPEs and Que were 450 mg/kg/d and 50 mg/kg/d, respectively. After 91 days of continuous intervention, compared with control group, the testes weight, epididymis weight, serum sex hormones, and anogenital distance were significantly decreased in MPEs group (P < 0.05); Testicular histopathological observation showed that all seminiferous tubules were atrophy, leydig cells were hyperplasia, spermatogenic cells growth were arrested in MPEs group. Ultrastructural observation of testicular germ cells showed that the edges of the nuclear membranes were indistinct, and the mitochondria were severely damaged with the cristae disrupted, decreased or even disappeared in MPEs group. Immunohistochemistry and Western blot analysis showed that testicular CYP11A1, CYP17A1 and 17β-HSD were up-regulated, while StAR, PIWIL1 and PIWIL2 were down-regulated in MPEs group (P < 0.05); However, the alterations of these parameters were restored in MPEs+Que group. The results indicated MPEs disturbed steroid hormone metabolism, and caused male reproductive injuries; whereas, Que could inhibit MPEs' male reproductive toxicity, which might relate to the restored regulation of steroid hormone metabolism.

Hazards of phthalates (PAEs) exposure: A review of aquatic animal toxicology studies

Phthalates (PAEs) are of wide concern because they are commonly used in various plastic products as plasticizers, and can found their way into the environment. However, their interaction with the environment and their toxicity in aquatic animals is still a matter of intense debate. In this review on PAEs in aquatic environments (lakes, rivers and seas), it is found that there is a large variety and abundance of PAEs in developing countries, and the total concentration of PAEs even exceeds 200 μg / L. The interaction between metabolic processes involved in the toxicity induced by various PAEs is summarized for the first time in the article. Exposure of PAEs can lead to activation of the detoxification system CYP450 and endocrine system receptors of aquatic animals, which in turn causes oxidative stress, metabolic disorders, endocrine disorders, and immunosuppression. Meanwhile, each system can activate / inhibit each other, causing genotoxicity and cell apoptosis, resulting in the growth and development of organisms being blocked. The mixed PAEs shows no cumulative toxicity changes to aquatic animals. For the combined pollution of other chemicals and PAEs, PAE can act as an agonist or antagonist, leading to combined toxicity in different directions. Phthalate monoesters (MPEs), the metabolites of PAEs, are also toxic to aquatic animals, however, the toxicity is weaker than the corresponding parent compounds. This review summarizes and analyzes the current ecotoxicological effects of PAEs on aquatic animals, and provides guidance for future research.

Effects of butyl benzyl phthalate exposure on Daphnia magna growth, reproduction, embryonic development and transcriptomic responses

Butyl benzyl phthalate (BBP) is widely used as a plasticizer to increase the plasticity and flexibility of plastic products. Although the potential health hazards of BBP have recently received extensive attention, its toxicological properties and mechanisms remain largely undefined. In the present work, growth, reproductive and developmental toxicity of BBP to Daphnia magna were evaluated, and the transcriptomic alteration of early embryos upon BBP exposure was analyzed. In a 21-day chronic toxicity test, reduced survival ratio, decreased body length, increased abnormal ratio, advanced time to first brood, and reduced offspring of D. magna were observed. BBP exposure inhibited expression of the vitellogenin gene. In addition, embryotoxicity of BBP was observed, which showed not only in the induction of abnormal neonates, but also in the shortened embryonic development cycle. RNA-Seq of early embryo treated with 0.1 mg/L BBP indicated that the pathways involved in signal transduction, cell communication, and embryonic development were significantly down-regulated, while those of biosynthesis, metabolism, cell homeostasis, redox homeostasis were remarkably up-regulated upon BBP exposure, which was consistent with the above phenotypic results. Taken together, our results highlight the toxic effects of BBP on the embryonic development and larval growth of D. magna.

Butyl benzyl phthalate (BBP) induces caudal defects during embryonic development

Butyl benzyl phthalate (BBP) is commonly added during the manufacturing of plastics to increase flexibility and elasticity. However, BBP leaches off of plastic and environment presence has been detected in soil, groundwater and sediment potentially effecting organisms in the environment. Given the widespread uses of BBP in household, consumer goods and the presence of BBP in the environment, studies on developmental toxicity are needed. Here, we use a zebrafish model to investigate the early developmental toxicity of BBP. We treated gastrula staged embryos with increasing concentrations of BBP and noted concentration-dependent defects in caudal tail development, but the effect was caudal specific with no other developmental defects noted. In situ hybridization studies using muscle and notochord markers show alterations in muscle development and non-linear, kinked notochord staining. A more detailed antibody staining using a myosin specific marker shows disorganized myofibrils and a loss of chevron shaped somites. Furthermore, vascular development in the tail was also disrupted in a concentration dependent manner. We conclude that BBP is toxic to caudal development in zebrafish. The sensitivity of zebrafish during development to environmental toxins and chemicals has been useful in assessing the health of the aquatic environment. The results presented here are a useful early warning system for contamination that could affect human health.

Couples' urinary bisphenol A and phthalate metabolite concentrations and the secondary sex ratio

With limited research focusing on non-persistent chemicals as exogenous factors affecting human sex selection, this study aimed to evaluate the association of urinary bisphenol A (BPA) and phthalate metabolite concentrations with the secondary sex ratio (SSR), defined as the ratio of male to female live births. The current analysis is limited to singleton live births (n=220, 43.9%) from the Longitudinal Investigation of Fertility and the Environment (LIFE) Study, in which couples discontinuing contraception with the intention of becoming pregnant were enrolled and followed while trying for pregnancy and through delivery for those achieving pregnancy. Using modified Poisson regression models accounting for potential confounders, we estimated the relative risks (RRs) of a male birth per standard deviation change in the log-transformed maternal, paternal, and couple urinary BPA and 14 phthalate metabolite concentrations (ng/mL) measured upon enrollment. When maternal and paternal chemical concentrations were modeled jointly, paternal BPA (RR, 0.77; 95% confidence interval [CI], 0.62-0.95) and mono-isobutyl phthalate (RR, 0.82; 95% CI, 0.67-1.00) were significantly associated with a female excess. Contrarily, maternal BPA (RR, 1.16; 95% CI, 1.03-1.31), mono-isobutyl phthalate (RR, 1.28; 95% CI, 1.06-1.54), mono-benzyl phthalate (RR, 1.31; 95% CI, 1.08-1.58), and mono-n-butyl phthalate (RR, 1.24; 95% CI, 1.01-1.51) were significantly associated with a male excess. These findings underscore varying patterns for the SSR in relation to parental exposures. Given the absence of previous investigation, these partner-specific associations of non-persistent chemicals with the SSR need future corroboration.