Pyriproxyfen (PPF), a broad-spectrum insecticide known to cause reproductive and endocrine disruption in invertebrates, while the data is scarce in aquatic vertebrates. The goal of this study is to ...investigate the impact of PPF on reproductive endocrine system of male and female zebrafish along hypothalamus-pituitary-gonadal (HPG) axis. In brain, PPF caused significant alteration in the transcripts of erα, lhβ, and cyp19b genes in male and fshβ, lhβ, and cyp19b genes in female zebrafish. The downstream genes of steroidogenic pathway like, star, 3βhsd, 17βhsd, and cyp19a expression were significantly altered in gonad of both sexes. Subsequent changes in circulatory steroid hormone levels lead to imbalance in hormone homeostasis as revealed from estradiol/testosterone (E2/T) ratio. Further, the vitellogenin transcript level was enhanced in hepatic tissues and their blood plasma content was increased in male (16.21%) and declined in female (21.69%). PPF also induced histopathological changes in gonads such as, reduction of mature spermatocytes in male and vitellogenic oocytes in female zebrafish. The altered E2/T ratio and gonadal histopathology were supported by the altered transcript levels of HPG axis genes. Overall, these findings provide new insights of PPF in zebrafish reproductive system and highlights for further investigations on its potential risks in aquatic environment.
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•The endocrine disruptive potential of pyriproxyfen (PPF) was studied in zebrafish.•PPF altered the gonadotropin and steroidogenic transcript levels in both sexes.•Blood plasma concentration of testosterone and estradiol were significantly differed.•Vitellogenin expression was enhanced in liver and varied in blood plasma level.•PPF exposure caused histopathological damages in testes and ovary of zebrafish.
•PPF toxicity in zebrafish embryos was studied using multiple biomarker endpoints.•PPF causes severe developmental abnormalities in 1.66 μg/mL concentration.•PPF alters biochemical and antioxidant ...responses and inhibits AChE.•PPF causes DNA damage and alters histology at 1.66 μg/mL concentration.
Pyriproxyfen (2-1-methyl-2-(4-phenoxyphenoxy) ethoxy pyridine) (PPF), a pyridine-based pesticide widely used to control agricultural insect pests and mosquitoes in drinking water sources. However, its ecotoxicological data is limited in aquatic vertebrates particularly in fish. Hence, the present study aimed to evaluate the adverse effect of PPF in zebrafish embryo development (Danio rerio). In order to investigate the impact of PPF, embryos were exposed to 0.16, 0.33 and 1.66 μg/mL (0.52, 1.04 and 5.2 μM, respectively) for 96 hpf and various biomarker indices such as developmental toxicity (edema formation, hyperemia, heart size and scoliosis), oxidative stress (reactive oxygen species (ROS), lipid peroxidation (LPO) and nitric oxide (NO)), antioxidant responses (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx) and reduced glutathione (GSH)), biochemical (lactate dehydrogenase (LDH) and acid phosphatase (AP)), neurotoxicity (acetylcholinesterase (AChE)), genotoxicity (apoptosis and DNA damage) and histopathological changes were determined. The results showed that severe developmental deformities and changes in heart rate were observed in embryos treated with highest (1.66 μg/mL) concentration than the control (P < 0.05). Heart size measurement showed that, significant change in heart size (P < 0.01) was observed in embryos of 96 hpf only at 1.66 μg/mL PPF exposure. The oxidative stress was apparent at highest test concentration (1.66 μg/mL) as reflected by the elevated ROS, LPO and NO and changes in antioxidant enzyme activities including SOD, CAT, GST and GPx (P < 0.05). Besides, GSH level and AChE activity were significantly lowered in 1.66 μg/mL PPF exposed group than the control. After 96 hpf of PPF exposure, no significant changes were found in AP activity whereas, a biphasic response was observed in the LDH activity. There was no genotoxic effect in embryos exposed to PPF at 0.16 and 0.33 μg/mL, while significant (P < 0.05) DNA damage and apoptosis were found in 1.66 μg/mL treated group. Histopathological analysis revealed that exposure to PPF at 1.66 μg/mL resulted in thinning of heart muscles, pericardial edema and hyperemia while there was no obvious changes were observed in other treatment groups. Hence, the results of the present study demonstrate that PPF could cause adverse effect on early developmental stages of zebrafish at higher concentration.
Background: Zishen Guchong Pill (ZGP), a traditional oriental herbal medicine, has been applied broadly in the treatment of threatened or recurrent miscarriages in clinics, but little is known about ...its developmental toxicity.
Aim of the study: This study aimed to investigate the potential toxicity of ZGP and its mechanisms.
methods: We investigated the developmental toxicity of ZGP using a zebrafish model. Zebrafish embryos at 4 hours post-fertilization (hpf) were exposed to 25, 50, 100, and 200 µg/mL ZGP until 120 hpf. The zebrafish morphology, organ development, reactive oxygen species (ROS) content, oxidative stress-related enzyme activity, and mRNA levels of oxidative stress and apoptosis-related genes were measured.
Results: Our results demonstrated that ZGP had no toxicity at 50 µg/mL ZGP but induced phenotypic defects and decreased the hatching rate and body length at more than 50 µg/mL ZGP (high dose). High doses of ZGP caused severe heart failure, including a significant increase in the sinus venosus (SV) and bulbus arteriosus (BA) distance and pericardial area, and reduced heart rate and numbers of red blood cells. In addition, high doses of ZGP caused liver atrophy and decreased the length of dopamine ganglia and neurovascular. High doses of ZGP elicited the generation of ROS and elevated malondialdehyde levels, but reduced the activity of superoxide dismutase (SOD) and catalase (CAT). Real-time PCR data showed the downregulation of oxidative stress-related genes (sod and cat) and the activation of Nrf2 (nrf2, keap1, ho-1, nqo1, gclc, and gclm) and P53 (p53, bcl-2, and bax) signal pathway genes after high ZGP exposure.
Conclusions: Taken together, our results indicate that ZGP has no developmental toxicity under 50 µg/mL ZGP but induced developmental toxicity in zebrafish embryos at more than 50 µg/mL ZGP, and oxidative stress contributed to the toxic response.•ZGP is safe and reliable in clinical use.•ZGP (high does) caused an increase in ROS, which induced oxidative stress, leading to apoptosis and developmental toxicity.•The Nrf2 signaling pathway is impaired during the early stages of ZGP-induced developmental toxicity.
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In the present study, we evaluated the zearalenone induced adverse effects in zebrafish embryos using various endpoints like embryo toxicity, heart rate, oxidative stress indicators (reactive oxygen ...species (ROS), lipid peroxidation (LPO), Nitric oxide (NO)), antioxidant responses (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase enzyme (GST) and reduced glutathione (GSH), metabolic biomarkers (lactate dehydrogenase (LDH) and Nitric oxide (NO)), neurotoxicity (acetylcholinesterase (AChE)), genotoxicity (comet assay and acridine orange staining (AO)) and histological analysis. In this study, four concentrations 350, 550, 750 and 950 μg/L of ZEA were chosen based on LC10 and LC50 values of the previous report. The results shows that ZEA induces developmental defects like pericardial edema, hyperemia, yolk sac edema, spine curvature and reduction in heart rate from above 550 μg/L exposure and the severity was increased with concentration and time dependent manner. Significant induction in oxidative stress indices (ROS, LPO and NO), reduction in antioxidant defence system (SOD, CAT, GPx, GST and GSH) and changes in metabolic biomarkers (LDH and AP) were observed at higher ZEA exposed concentration. Neurotoxic effects of ZEA were observed with significant inhibition of AChE activity at higher exposure groups (750 and 950 μg/L). Moreover, we also noticed DNA damage, apoptosis and histological changes in the higher ZEA treatments at 96 h post fertilization (hpf) embryos. Hence, in the present study we concluded that oxidative stress is the main culprit in ZEA induced developmental, genotoxicity and neurotoxicity in zebrafish embryos.
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•The effect of ZEA on zebrafish during early embryonic development was studied.•Dosages higher than 550 μg/L ZEA exposure resulted in developmental defects.•ZEA induced oxidative stress, DNA damage and apoptosis was reported.•ZEA could alter histopathology and inhibits AChE activity in zebrafish embryos.
The present study was aimed to evaluate the bio-control efficacy of Pediococcus pentosaceus isolated from traditional fermented dairy products originated from India, against the growth and ...zearalenone (ZEA) production of Fusarium graminearum. The cell-free supernatants of P. pentosaceus (PPCS) were prepared and chemical profiling was carried out by GC-MS and MALDI-TOF analysis. Chemical profiling of PPCS evidenced that, the presence of phenolic antioxidants, which are responsible for the antifungal activity. Another hand, MALDI-TOF analysis also indicated the presence of antimicrobial peptides. To know the antioxidant potential of PPCS, DPPH free radical scavenging assay was carried out and IC50 value was determined as 32 ± 1.89 μL/mL. The antifungal activity of P. pentosaceus was determined by dual culture overlay technique and zone of inhibition was recorded as 47 ± 2.81%, and antifungal activity of PPCS on F. graminearum was determined by micro-well dilution and scanning electron microscopic techniques. The minimum inhibitory concentration (MIC) of PPCS was determined as 66 ± 2.18 μL/mL in the present study. Also a clear variation in the micromorphology of mycelia treated with MIC value of PPCS compared to untreated control was documented. Further, the mechanism of growth inhibition was revealed by ergosterol analysis and determination of reactive oxygen species (ROS) in PPCS treated samples. The effects of PPCS on mycelial biomass and ZEA production were observed in a dose-dependent manner. The mechanism behind the suppression of ZEA production was studied by reverse transcriptase qPCR analysis of ZEA metabolic pathway genes (PKS4 and PKS13), and results showed that there is a dose dependent down-regulation of target gene expression in PPCS treated samples. The results of the present study were collectively proved that, the antifungal and ZEA inhibitory activity of PPCS against F. graminearum and it may find a potential application in agriculture and food industry as a natural bio-controlling agent.
In the present study, we aimed to assess the adverse effects of zearalenone (ZEA) at environmentally relevant concentrations (0.5, 1, 5 and 10 μg l−1) on hypothalamic–pituitary–gonadal axis ...associated reproductive function using zebrafish model. ZEA was exposed to female zebrafish for 21 days to assess growth indices such as condition factor, hepatosomatic index, gonadosomatic index and caspase 3 activity. Further, expression of estrogen receptor (ER) α and CYP19a1b genes in the brain, ERα and vitellogenin (Vtg) genes in the liver and follicle‐stimulating hormone receptor, luteinizing hormone receptor, ERα, steroidogenic acute regulatory protein, 3β‐hydroxysteroid dehydrogenase (HSD), 17‐βHSD and CYP19a1 genes in the ovary were also investigated. Our results showed that there were no significant changes in the condition factor and hepatosomatic index, whereas a significant (P < .05) reduction in the gonadosomatic index, increase in caspase 3 activities and Vtg expression was observed at higher concentration. However, no significant changes were observed at lower treatment levels. Further, we also observed significant (P < .05) upregulation in ERα, Vtg, luteinizing hormone receptor, steroidogenic acute regulatory protein, 3β‐HSD, 17β‐HSD, CYP19a1 and CYP19a1b genes in treatment groups with higher levels of ZEA. Moreover, in histopathological examination, we observed oocyte atresia and oocyte membrane detachment in ovaries at the highest concentration. In conclusion, the present study revealed the negative impact of ZEA on zebrafish reproductive system by involvement of the hypothalamic–pituitary–gonadal axis‐associated reproductive function.
The aim of the present study was to evaluate the adverse effects of Zearalenone on reproductive functions of adult female zebrafish. Zearalenone affects the gonad functions in female zebrafish by changing growth indices and histology of ovary. Moreover, zearalenone alters the hypothalamus‐pituitary‐gonadal axis by varying the expressions of steroidogenic hormone encoding genes, consequently affects the reproductive system of zebrafish. Hence, zearalenone could pose threat to aquatic organisms by impairing reproductive physiology.
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