Based on metabolomics,the metabolites of larvae zebrafish with overdose of Panax notoginseng saponins( PNS) were compared with those in normal group of larvae zebrafish to investigate the possible toxicity mechanism of overdose PNS in larvae zebrafish. An experimental animal model of long-term toxicity induced by PNS overdose was established by administering 1-6 dpf at low,medium and high doses of PNS,respectively. The ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry( UPLC-Q-TOF-MS) technique was combined with principal component analysis( PCA) and orthogonal partial least squares discriminant analysis( OPLS-DA) to screen and identify biomarkers associated with toxicity,and then the MetaboAnalyst database was used to analyze metabolism-related pathways. The results showed that the metabolites of each group could be distinguished distinctly,and they deviated more from the normal group in a time and dose dependent manner. Twenty-nine potential biomarkers related to toxicity( VIP>1,P<0. 05) were identified preliminarily,mainly involving six metabolic pathways. From the metabonomics point of view,the toxicity mechanism of overdose PNS may be related to the disorders of lipid metabolism,amino acid metabolism and energy metabolism.
Amino Acids ; metabolism ; Animals ; Chromatography, High Pressure Liquid ; Energy Metabolism ; Larva ; drug effects ; Lipid Metabolism ; Mass Spectrometry ; Metabolomics ; Panax notoginseng ; toxicity ; Saponins ; toxicity ; Toxicity Tests, Acute ; Zebrafish

Animals always seek rewards and the related neural basis has been well studied. However, what happens when animals fail to get a reward is largely unknown, although this is commonly seen in behaviors such as predation. Here, we set up a behavioral model of repeated failure in reward pursuit (RFRP) in Drosophila larvae. In this model, the larvae were repeatedly prevented from reaching attractants such as yeast and butyl acetate, before finally abandoning further attempts. After giving up, they usually showed a decreased locomotor speed and impaired performance in light avoidance and sugar preference, which were named as phenotypes of RFRP states. In larvae that had developed RFRP phenotypes, the octopamine concentration was greatly elevated, while tβh mutants devoid of octopamine were less likely to develop RFRP phenotypes, and octopamine feeding efficiently restored such defects. By down-regulating tβh in different groups of neurons and imaging neuronal activity, neurons that regulated the development of RFRP states and the behavioral exhibition of RFRP phenotypes were mapped to a small subgroup of non-glutamatergic and glutamatergic octopaminergic neurons in the central larval brain. Our results establish a model for investigating the effect of depriving an expected reward in Drosophila and provide a simplified framework for the associated neural basis.
Acetates ; pharmacology ; Animals ; Animals, Genetically Modified ; Avoidance Learning ; physiology ; Biogenic Amines ; metabolism ; Conditioning, Operant ; physiology ; Drosophila ; physiology ; Drosophila Proteins ; genetics ; metabolism ; Feeding Behavior ; drug effects ; physiology ; Instinct ; Larva ; physiology ; Locomotion ; drug effects ; genetics ; Nervous System ; cytology ; Neurons ; physiology ; Octopamine ; metabolism ; RNA Interference ; physiology ; Reward ; Statistics, Nonparametric ; Transcription Factors ; genetics ; metabolism

Decabromodiphenylethane (DBDPE) has been widely used as an alternative flame retardant due to the restriction or phase-out of traditional polybrominated diphenyl ethers (PBDEs), and is of increasing concern regarding its ubiquity, persistence, and potential adverse effects. In the present study, the toxicological effects of DBDPE were evaluated using zebrafish as an in vivo model. Upon being exposed to DBDPE-polluted sediments for a short term, it was found that the mortality and malformation of zebrafish (including edema, bent notochord, and bent tail) were not affected even at the highest concentration tested (1000.0 µg/kg dry sediment). Regarding behavioral responses, it was found that zebrafish larvae of 48 hours post fertilization (hpf) in all groups escaped successfully with a touch to the dorsal fin. However, when exposed to the highest DBDPE concentration, the larvae of 120 hpf exhibited significantly smaller distances as compared to the control. Moreover, the results of the acetylcholinesterase (AChE) activity, the expression levels of two important nerve-related genes, and the cell apoptosis all indicated that DBDPE posed low neurotoxicity in embryo-larval zebrafish. The results in this study shed some light on the potential risks of DBDPE in the real environment and highlight the application of the sediment exposure route in the future.
Abnormalities, Drug-Induced ; etiology ; Animals ; Apoptosis ; drug effects ; Behavior, Animal ; drug effects ; Bromobenzenes ; toxicity ; Geologic Sediments ; analysis ; Larva ; drug effects ; Neurotoxicity Syndromes ; etiology ; Water Pollutants, Chemical ; toxicity ; Zebrafish ; embryology

PURPOSE: microRNAs (miRNAs) are non-coding RNAs composed of 20 to 22 nucleotides that regulate development and differentiation in various organs by silencing specific RNAs and regulating gene expression. In the present study, we show that the microRNA (miR)-183 cluster is upregulated during hair cell regeneration and that its inhibition reduces hair cell regeneration following neomycin-induced ototoxicity in zebrafish. MATERIALS AND METHODS: miRNA expression patterns after neomycin exposure were analyzed using microarray chips. Quantitative polymerase chain reaction was performed to validate miR-183 cluster expression patterns following neomycin exposure (500 µM for 2 h). After injection of an antisense morpholino (MO) to miR-183 (MO-183) immediately after fertilization, hair cell regeneration after neomycin exposure in neuromast cells was evaluated by fluorescent staining (YO-PRO1). The MO-183 effect also was assessed in transgenic zebrafish larvae expressing green fluorescent protein (GFP) in inner ear hair cells. RESULTS: Microarray analysis clearly showed that the miR-183 cluster (miR-96, miR-182, and miR-183) was upregulated after neomycin treatment. We also confirmed upregulated expression of the miR-183 cluster during hair cell regeneration after neomycin-induced ototoxicity. miR-183 inhibition using MO-183 reduced hair cell regeneration in both wild-type and GFP transgenic zebrafish larvae. CONCLUSION: Our work demonstrates that the miR-183 cluster is essential for the regeneration of hair cells following ototoxic injury in zebrafish larvae. Therefore, regulation of the miR-183 cluster can be a novel target for stimulation of hair cell regeneration.
Animals ; Animals, Genetically Modified ; Cell Count ; Gene Expression Profiling ; Gene Expression Regulation/drug effects ; Gene Knockdown Techniques ; Green Fluorescent Proteins/metabolism ; Hair Cells, Auditory/drug effects ; Hair Cells, Auditory/physiology ; Larva/drug effects ; Larva/genetics ; MicroRNAs/genetics ; MicroRNAs/metabolism ; Morpholinos/pharmacology ; Neomycin/toxicity ; Regeneration/drug effects ; Regeneration/genetics ; Zebrafish/genetics

Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is the main component in hot peppers, including red chili peppers, jalapenos, and habanero, belonging to the genus Capsicum. Capsaicin is a potent antioxidant that interferes with free radical activities. In the present study, the possible protective effect of capsaicin was studied against methyl methanesulphonate (MMS) induced toxicity in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg. The third instar was allowed to feed on the diet having different doses of capsaicin and MMS separately and in combination. The results suggested that the exposure of third instar larvae to the diet having MMS alone showed significant hsp70 expression as well as tissue DNA and oxidative damage, whereas the larvae feed on the diet having MMS and capsaicin showed a decrease in the toxic effects for 48-h of exposure. In conclusion, capsaicin showed a dose-dependent decrease in the toxic effects induced by MMS in the third instar larvae of transgenic Drosophila melanogaster.
Acetylcholinesterase ; metabolism ; Animals ; Animals, Genetically Modified ; Anticarcinogenic Agents ; pharmacology ; Capsaicin ; pharmacology ; DNA Damage ; drug effects ; Drosophila melanogaster ; drug effects ; Larva ; drug effects ; Methyl Methanesulfonate ; antagonists & inhibitors

OBJECTIVETo evaluate the bio-safety of graphene quantum dots (GQDs), we studied its effects on the embryonic development of zebrafish.

METHODSIn vivo, biodistribution and the developmental toxicity of GQDs were investigated in embryonic zebrafish at exposure concentrations ranging from 12.5-200 μg/mL for 4-96 h post-fertilization (hpf). The mortality, hatch rate, malformation, heart rate, GQDs uptake, spontaneous movement, and larval behavior were examined.

RESULTSThe fluorescence of GQDs was mainly localized in the intestines and heart. As the exposure concentration increased, the hatch and heart rate decreased, accompanied by an increase in mortality. Exposure to a high level of GQDs (200 μg/mL) resulted in various embryonic malformations including pericardial edema, vitelline cyst, bent spine, and bent tail. The spontaneous movement significantly decreased after exposure to GQDs at concentrations of 50, 100, and 200 μg/mL. The larval behavior testing (visible light test) showed that the total swimming distance and speed decreased dose-dependently. Embryos exposed to 12.5 μg/mL showed hyperactivity while exposure to higher concentrations (25, 50, 100, and 200 μg/mL) caused remarkable hypoactivity in the light-dark test.

CONCLUSIONLow concentrations of GQDs were relatively non-toxic. However, GQDs disrupt the progression of embryonic development at concentrations exceeding 50 μg/mL.

Animals ; Behavior, Animal ; Dose-Response Relationship, Drug ; Embryo, Nonmammalian ; abnormalities ; drug effects ; Graphite ; administration & dosage ; chemistry ; toxicity ; Larva ; drug effects ; Quantum Dots ; administration & dosage ; chemistry ; toxicity ; Zebrafish ; embryology

To evaluate the effects of pesticides to parasite eggs, Ascaris suum eggs were incubated with 5 different pesticides (1:1,500-1:2,000 dilutions of 2% emamectin benzoate, 5% spinetoram, 5% indoxacarb, 1% deltamethrin, and 5% flufenoxuron; all v/v) at 20degrees C for 6 weeks, and microscopically evaluated the egg survival and development on a weekly basis. The survival rate of A. suum eggs incubated in normal saline (control eggs) was 90+/-3% at 6 weeks. However, the survival rates of eggs treated with pesticides were 75-85% at this time, thus significantly lower than the control value. Larval development in control eggs commenced at 3 weeks, and 73+/-3% of eggs had internal larvae at 6 weeks. Larvae were evident in pesticide-treated eggs at 3-4 weeks, and the proportions of eggs carrying larvae at 6 weeks (36+/-3%-54+/-3%) were significantly lower than that of the control group. Thus, pesticides tested at levels similar to those used in agricultural practices exhibited low-level ovicidal activity and delayed embryogenesis of A. suum eggs, although some differences were evident among the tested pesticides.
Animals ; Ascaris suum/*drug effects/growth & development ; Female ; Larva/drug effects/growth & development ; Microscopy ; Pesticides/*pharmacology ; Survival Analysis ; Temperature ; Time ; Zygote/*drug effects/growth & development

To investigate vincristine-induced dopaminergic neurons toxicity and mechanism, and explore the molecular target to reduce the toxicity, zebrafish was chosen as a model animal, based on RT-PCR, Western blotting, whole mount in situ immunofluorescence and other technical means. The results showed that the transcription levels of tyrosine hydroxylase gene and dopamine transporter protein gene were inhibited. Furthermore, the number of dopaminergic neurons was decreased by vincristine. Autophagy was suppressed and beclin1 gene expression was inhibited in a dose-dependent manner by vincristine in larval zebrafish. Up-regulated beclin1 partly reduced vincristine-induced neurotoxicity, and down-regulated beclin1 increased toxicity. Beclin1 plays an important role in vincristine-induced dopaminergic neurons toxicity.
Animals ; Apoptosis Regulatory Proteins ; metabolism ; Autophagy ; Dopaminergic Neurons ; drug effects ; pathology ; Dose-Response Relationship, Drug ; Down-Regulation ; Gene Expression Regulation ; drug effects ; Larva ; drug effects ; Tyrosine 3-Monooxygenase ; metabolism ; Vincristine ; adverse effects ; Zebrafish ; Zebrafish Proteins ; metabolism

Histone deacetylases are involved in many biological processes and have roles in regulating cell behaviors such as cell cycle entry, cell proliferation and apoptosis. However, the effect of histone deacetylases on the development of hair cells (HCs) has not been fully elucidated. In this study, we examined the influence of histone deacetylases on the early development of neuromasts in the lateral line of zebrafish. Hair cell development was evaluated by fluorescent immunostaining in the absence or presence of histone deacetylase inhibitors. Our results suggested that pharmacological inhibition of histone deacetylases with inhibitors, including trichostatin A, valproic acid and MS-275, reduced the numbers of both HCs and supporting cells in neuromasts. We also found that the treatment of zebrafish larvae with inhibitors caused accumulation of histone acetylation and suppressed proliferation of neuromast cells. Real-time PCR results showed that the expression of both p21 and p27 mRNA was increased following trichostatin A treatment and the increase in p53 mRNA was modest under the same conditions. However, the expression of p53 mRNA was significantly increased by treatment with a high concentration of trichostatin A. A high concentration of trichostatin A also led to increased cell death in neuromasts as detected in a TUNEL assay. Moreover, the nuclei of most of these pyknotic cells were immunohistochemically positive for cleaved caspase-3. These results suggest that histone deacetylase activity is involved in lateral line development in the zebrafish and might have a role in neuromast formation by altering cell proliferation through the expression of cell cycle regulatory proteins.
Animals ; Apoptosis ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor Proteins/genetics/metabolism ; Histone Deacetylase Inhibitors/*pharmacology ; Histone Deacetylases/*metabolism ; Histones/metabolism ; Larva/growth & development/metabolism ; Lateral Line System/cytology/*growth & development/metabolism ; Mechanoreceptors/drug effects/*metabolism/physiology ; RNA, Messenger/genetics/metabolism ; Zebrafish ; Zebrafish Proteins/*metabolism

OBJECTIVETo evaluate the ovicidal and larvicidal activities of aqueous and ethanolic extracts of leaves of Dichrocephala integrifolia (D. integrifolia) against the eggs (fresh and embryonnated), the first and second larval stages of Heligmosomoides bakeri. In order to verify if this medicinal plant possesses active compounds capable of inhibiting the embryonation and hatching of eggs or to induce the mortality of larvae (L1 and L2).

METHODSdried extracts were diluted in distilled FIV water to obtain five different concentrations: 625, 1,250, 2,500, 3,750 and 5,000 µg/mL. Fresh eggs obtained from artificially infected mice feces were exposed to these different concentrations for 48 h. Time of contact for embryonated eggs was 6 h while L1 and L2 larvae were exposed for 24 h. Distilled water (placebo) and 1.5% DMSO were used as negative controls.

RESULTSDistilled water, and 1.5% DMSO had no effect on embryonation, hatching and larval survival. Aqueous extracts of D. integrifolia showed a weak activity against all stages of the parasite at all concentrations tested. On the contrary, the ethanolic extract of D. integrifolia inhibited the embryonation of 87.5% of fresh eggs, the hatching of 81.1% of embryonated eggs and induced the mortality of 98.1% and 98% of L1 and L2 larvae respectively at 5,000 µg/mL.

CONCLUSIONSThe results of the present study indicate that the ethanolic extracts of D. integrifolia contained compounds with ovicidal and larvicidal properties. In spite of these results, in vivo tests, studies on toxicity and mechanism of action of active compounds are also needed to validate the utilisation of this medicinal plant by population of Dschang-Cameroon to treat gastro-intestinal parasites.

Animals ; Antinematodal Agents ; pharmacology ; therapeutic use ; Asteraceae ; chemistry ; Dose-Response Relationship, Drug ; Heligmosomatoidea ; drug effects ; growth & development ; Larva ; drug effects ; Mice ; parasitology ; Ovum ; drug effects ; Plant Extracts ; pharmacology ; therapeutic use ; Plant Leaves ; chemistry ; Rodent Diseases ; drug therapy ; Strongylida Infections ; drug therapy ; veterinary