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Objective@#To investigate the developmental toxicity of 2,4-dinitrochlorobenzene in zebrafish embryos.@*Methods@#AB wild-type male and female zebrafish were selected to mate and spawn, then the eggs were cultured with Holt buffer solution. Six dose groups ( 0.4, 0.8, 1.0, 1.2, 1.6, 2.0 μg/mL ), a solvent control group and a cosolvent control group, were set up with 20 embryos each. Malformations and death of embryos were observed at 48, 72 and 96 hpf ( hours post fertilization ), the mortality and 50% lethal concentration ( LC50 ) were also calculated. @*Results@#At 48, 72 and 96 hpf, the LC50 of 2,4-dinitrochlorobenzene on zebrafish embryos were 1.668, 1.043 and 0.895 μg/mL, respectively, with a downward trend. After 72 hpf, when the concentration reached 2.0 μg/mL, all the zebrafish died. In the range of 0.4-2.0 μg/mL, the mortality of zebrafish at 48, 72 and 96 hpf increased with the increase of 2,4-dinitrochlorobenzene concentration ( all P<0.05 ); the malformation rate of zebrafish embryos at 48 hpf increased with the increase of 2,4-dinitrochlorobenzene concentration ( P<0.05 ). Zebrafish embryos exposed to 2,4-dinitrochlorobenzene led to yolk sac edema, pericardial edema and spinal curvature. @*Conclusion@#2,4-dinitrochlorobenzene can affect the development of zebrafish embryos, which will lead to lethal and teratogenic effects.
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Objective:Taking zebrafish embryos as research model, to investigate the toxic effect of different polar fractions of Euphorbiae Pekinensis Radix before and after processing with vinegar on heart. Method:Zebrafish embryos with normal development at 12 h after fertilization were treated with petroleum ether, dichloromethane and ethyl acetate extracts of Euphorbiae Pekinensis Radix before and after processing with vinegar for observation of cardiac development and function at 72 h. Result:Various polar fractions of Euphorbiae Pekinensis Radix before and after processing with vinegar had the cardiotoxicity on zebrafish embryos in a dose-dependent manner. In addition, the cardiotoxicity of different polar fractions was followed by petroleum ether, dichloromethane and ethyl acetate. The cardiotoxicity was mainly manifested as slow cardiac development, pericardial edema, decrease of heart rate and apoptosis of cardiac cells. Compared with the corresponding polar fraction of raw products, the cardiotoxicity of the same polar fraction of vinegar-processed products with similar doses decreased. Conclusion:Euphorbiae Pekinensis Radix has cardiotoxicity to zebrafish embryos and the cardiotoxicity is reduced after processing with vinegar, which can provide some experimental basis for further elucidation of the detoxication mechanism of Euphorbiae Pekinensis Radix processed with vinegar.
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To study the effects of different fraction of Euphorbiae Pekinensis Radix before and after processing with vinegar on liver and gastrointestinal toxicity of zebrafish embryos,the zebrafish embryos after fertilized 12 h(12 hpf) were exposed to different concentrations of solution until 96 h(96 hpf),for observation of the toxicity response of the liver and gastrointestinal of individual zebrafish embryos. The results showed that toxicity increased in a dose-dependent manner. The liver and gastrointestinal toxicity of the zebrafish embryos in various polar fractions of Euphorbiae Pekinensis Radix before and after processing with vinegar was mainly manifested as slow liver development,smaller liver area,edema of yolk sac,delayed absorption,slowing of gastrointestinal motility,abnormal function of gastrointestinal goblet cell secretion. In addition,the toxicity of different polarity was followed by petroleum ether,dichloromethane,ethyl acetate. The above results indicated that the toxicity was reduced after processing with vinegar,and the fractions of petroleum ether and methylene chloride were the main sites responsible for liver and gastrointestinal toxicity.
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Animals , Acetic Acid , Drugs, Chinese Herbal , Liver , Plant Roots , ZebrafishABSTRACT
<p><b>OBJECTIVE</b>To investigate the mechanism underlying propofol- induced down-regulation of myelin basic protein (MBP) in zebrafish embryos.</p><p><b>METHODS</b>Zebrafish embryos (6-48 h post-fertilization [hpf]) were randomized into 4 equal groups for exposure to dimethyl sulfoxide (DMSO), 20 μg/mL propofol, 30 μg/mL propofol, or no particular treatment (control group). The larvae were collected at 48 or 72 hpf for detecting the mRNA levels of MBP, Olig1, Olig2, and Sox10 using qRT-PCR (=80). The protein expression of MBP was quantitatively detected using Western blotting (=80), and the apoptosis of the oligodendrocytes was investigated using TUNEL staining (=6).</p><p><b>RESULTS</b>Exposure to 20 and 30 μg/mL propofol caused significant reductions in the mRNA expressions of Olig1, Olig2, and Sox10 at 48 and 72 hpf ( < 0.05) and also in MBP mRNA and protein levels at 72 hpf ( < 0.05). Exposure to 30 μg/mL propofol induced more obvious reduction in MBP protein expression than 20 μg/mL propofol at 72 hpf ( < 0.05), and the exposures resulted in a significant increase of oligodendrocyte apoptosis at 72 hpf ( < 0.05).</p><p><b>CONCLUSIONS</b>Propofol exposure reduces MBP expression at both the mRNA and protein levels in zebrafish embryos by down-regulating the expressions of Olig1, Olig2 and Sox10 mRNA levels and increasing apoptosis of the oligodendrocytes.</p>
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Objective Herbal medicines containing toxic herbs or minerals such as Compound Danshen Tablet (CDT), Angong Niuhuang Pill (ANP), and Lidan Paishi Tablet (LPT) are avoided or used with caution for pregnant women because of potential teratogenicity. To understand their mechanism, they were chosen as model subjects for the research. Methods Zebrafish embryos were used to evaluate their potential teratogenic risk in vitro. Results All of them showed teratogenic and lethal effects in zebrafish embryos, with the EC50 values at 351, 793, and 220 μg/mL, and LC50 values at 417, 596, and 380 μg/mL, respectively. CDT and LPT, displaying week potential teratogenicity as their teratogenicity indexes were greater than 1, induced tail malformation and cardiac edema mainly in zebrafish embryos, respectively. Conclusion The results provide the significant guidance of clinical safety of medication.
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The 24 h normal developing zebrafish embryos were used to evaluate the acute toxicity and the compounds of respective fractions were analyzed by UFLC-Q-TOF-MS simultaneously. Nine concentration groups with respective concentration and a blank control group were designed for each fraction to investigate their effect on survival rates of zebrafish embryos 96 h after drug administration, and calculate the median lethal concentration (LC₅₀) of different fractions to zebrafish embryos. The results showed that all of the fractions had acute toxicity to zebrafish embryos except VEKD, and the order was as follows: VEKB, VEKC, VEKA and VEKD. According to the results of UFLC-Q-TOF-MS, the chemical ingredients contained in VEKB and VEKC were mainly composed of ingenane-type and japhane-type diterpenoids, respectively. It could be speculated that japhane-type diterpenoids might be the active compounds with lower toxicity associated with the results of toxicity study, providing some references for the further research on effective material basis of Kansui stir-baked with vinegar according to the principle of "drastic medicine, no death risks".
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Aim To explore the toxicity and safety of five kinds of known positive drugs, cyclophosphamide, acetyl salicylic acid, tetracycline hydrochloride, dexa-methasone acetate and azacitidine, using zebrafish em-bryos. Methods We selected normally developed 4 hpf zygote, and used water bath infecting method to add the drug to the artificial seawater. Each drug had five concentrating groups, a separate control group and solvent control group. We observed the dead zebrafish embryos after 120 hpf drugs, counted the number of deaths and deformities of zebrafish embryos, and cal-culated mortality abnormal rate, the median lethal con-centration (LC50 ), concentration for 50% of maximal effect (EC50 ), therapeutic index (TI) under 120 hpf condition. We also used the formula TI = LC50 / EC50 to calculate positive drug therapeutic index. Based on measured LC50 we calculated most nonlethal concentra-tion (MNLC) of each drug setting, namely 1 / 10 MN-LC, 1 / 3 MNLC, MNLC,LC10 four concentration, tha-lidomide as a positive control, vitamin C as a negative control, artificial seawater as control, 0. 5% DMSO as solvent control. Put in 28. 5 ℃ environment for 120 hours,embryo development was observed daily for de-velopmental state,mortality,deforming rate and abnor-mal condition. Results The result of five drugs LC50 in descending order: cyclophosphamide > azacitidine> tetracycline hydrochloride > acetylsalicylic acid >dexamethasone acetate. EC50 in descending order: cy-clophosphamide > tetracycline hydrochloride > azaciti-dine > acetylsalicylic acid > dexamethasone acetate. The TI values of cyclophosphamide, acetyl salicylic acid, tetracycline hydrochloride, dexamethasone ace-tate, azacitidine were 1. 92, 1. 11, 1. 05, 1. 44, 2. 99, respectively. Conclusion Zebrafish embryo model can be used in the preliminary evaluation of drugs, and the study of early developmental toxicity and safety.
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Genotoxic effects of silver nanoparticles (Ag-np) in a vertebrate model system were investigated. Effects and accumulation patterns of silver nanoparticles were studied using zebrafish embryos. Nanoparticles of silver were synthesized by chemical reduction of silver nitrate, using sodium borohydride as reducing agent and polyvinyl pyrolidene as a stabilizer. These nanoparticles were characterized by UV/ Vis spectrophotometer (absorption spectra), Transmission electron microscopy and were found to have the size range of 4 to 10 nm. Evaluation of cytotoxicity was carried out at various concentrations to obtain the LD50 value. Dose dependent decrease in percent viability was observed on exposure of embryos to different concentrations of silver nanoparticles with LD50 of 1.0 µg/ml. The results indicate that silver nanoparticles induce a dose-dependent toxicity in embryos and abrogate normal development.
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<p><b>OBJECTIVE</b>This study was aimed to investigate the toxic effects of 3 nanomaterials, i.e. multi-walled carbon nanotubes (MWCNTs), graphene oxide (GO), and reduced graphene oxide (RGO), on zebrafish embryos.</p><p><b>METHODS</b>The 2-h post-fertilization (hpf) zebrafish embryos were exposed to MWCNTs, GO, and RGO at different concentrations (1, 5, 10, 50, 100 mg/L) for 96 h. Afterwards, the effects of the 3 nanomateria on spontaneous movement, heart rate, hatching rate, length of larvae, mortality, and malformations ls were evaluated.</p><p><b>RESULTS</b>Statistical analysis indicated that RGO significantly inhibited the hatching of zebrafish embryos. Furthermore, RGO and MWCNTs decreased the length of the hatched larvae at 96 hpf. No obvious morphological malformation or mortality was observed in the zebrafish embryos after exposure to the three nanomaterials.</p><p><b>CONCLUSION</b>MWCNTs, GO, and RGO were all toxic to zebrafish embryos to influence embryos hatching and larvae length. Although no obvious morphological malformation and mortality were observed in exposed zebrafish embryos, further studies on the toxicity of the three nanomaterials are still needed.</p>
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Animals , Female , Male , Embryo, Nonmammalian , Embryonic Development , Graphite , Toxicity , Heart Rate , Movement , Nanotubes, Carbon , Toxicity , Oxides , Toxicity , Toxicity Tests , ZebrafishABSTRACT
AIM@#The application of strychnine (S) is limited due to its toxicity; strychnine N-oxide (SNO) is a derivative of strychnine. The aim was to employ zebrafish embryos to investigate and compare the developmental toxicity induced by S and SNO.@*METHODS@#The toxicity of S and SNO was examined through the hatching rate and survival rate. Morphological changes of the zebrafish were observed with a dissecting microscope. Apoptosis was detected through acridine orange (AO) staining and flow cytometry. Apoptotic genes were measured by RT-PCR.@*RESULTS@#Embryo malformation was observed in the embryos exposed to S at 200 μmol·L(-1). When SNO concentration was increased to 1 mmol·L(-1), scoliolosis, and pericardial edema could be seen in some embryos. Results from fluorescence microscopy and flow cytometry analysis showed that S at 200 μmol·L(-1) induced apoptosis, whereas the apoptotic rate in the SNO-treated group (200 μmol·L(-1)) was much lower than that in the S group. RT-PCR analysis showed that p53 mRNA expression and the ratio of Bax/Bcl-2 in the S group were significantly altered compared with the control group (*P < 0.05). Moreover, Bax mRNA expression in both S and SNO group were significantly different from that in the control group (**P < 0.01).@*CONCLUSION@#These results lead to the conclusion that SNO has significantly lower toxicity than S in zebrafish embryos.
Subject(s)
Animals , Female , Male , Apoptosis , Cyclic N-Oxides , Toxicity , Drugs, Chinese Herbal , Toxicity , Oxidative Stress , Proto-Oncogene Proteins c-bcl-2 , Strychnine , Toxicity , Strychnos , Chemistry , Tumor Suppressor Protein p53 , Genetics , Metabolism , Zebrafish , Embryology , Genetics , Metabolism , Zebrafish Proteins , Genetics , MetabolismABSTRACT
Nodal signals play important roles in mesendoderm induction, establishment of left-right asymmetry and anteroposterior patterning of the neuroectoderm during vertebrate embryogenesis. It is aimed at identifying Nodal-regulated genes in zebrafish embryos, particularly those encoding transcription factors. A (Affymetrix) genechip analysis was performed using RNAs derived from embryos injected with squint mRNA, MZoep mutant embryos that are deficient in Nodal signaling, and wildtype embryos at the 30% epiboly stage. Transcripts (genes) with at least two-fold changes in expression level between wildtype and the other samples were identified. In squint mRNA-injected embryos, 265 transcripts show an increased expression level and 111 have a decreased expression level; in MZoep embryos, the expression of 1 495 transcripts increases while 550 transcripts express at a decreased level. Furthermore, overexpression of squint causes increased expression of 26 and decreased expression of 11 annotated transcription factor genes; in MZoep embryos, the number of transcription factor genes showing an increase and decrease of expression are 69 and 30, respectively. These results would provide useful information for further studying mechanisms and biological functions of Nodal signal transduction.