This study used the zebrafish model to explore the hepatotoxicity of Rhododendri Mollis Flos(RMF). The mortality was calculated according to the number of the survival of zebrafish larvae 4 days after fertilization under different concentration of RMF, and the dose-toxicity curve was fitted to preliminarily evaluate the toxicity of RMF. The liver phenotypes under the sublethal concentration of RMF in the treatment group and the blank control group were observed by hematoxylin-eosin(HE) staining and acridine orange(AO) staining. Meanwhile, the activities of alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were determined to confirm the hepatotoxicity of RMF. Real-time quantitative polymerase chain reaction(real-time PCR) and Western blot were used to determine the expressions of genes and proteins in zebrafish larvae. Gas chromatography time-of-flight mass spectrometry(GC-TOF-MS) was used to conduct untargeted metabolomics testing to explore the mechanism. The results showed that the toxicity of RMF to zebrafish larvae was dose-dependent, with 1 100 μg·mL~(-1) of the absolute lethal concentration and 448 μg·mL~(-1) of sublethal concentration. The hepatocyte apoptosis and degeneration appeared in the zebrafish larvae under the sublethal concentration of RMF. The content of ALT and AST in zebrafish larvae at the end of the experiment was significantly increased in a dose-dependent manner. Under the sublethal concentration, the expressions of genes and proteins related to apoptosis in zebrafish larvae were significantly increased as compared with the blank control group. The results of untargeted metabolomics showed that the important metabolites related to the he-patotoxicity of RMF were mainly enriched in alanine, aspartic acid, glutamic acid, and other pathways. In conclusion, it is inferred that RMF has certain hepatotoxicity to zebrafish larvae, and its mechanism may be related to apoptosis.
Animals ; Zebrafish/genetics* ; Apoptosis ; Larva ; Chemical and Drug Induced Liver Injury

This paper compared the differences between two kinds of Bufonis Venenum produced by Bufo gargarizans gargarizans and B. gararizans andrewsi, and verified the rationality of the market value orientation of Bufonis Venenum based on the zebrafish mo-del. Twenty batches of Bufonis Venenum from Jiangsu province, Hebei province, Liaoning province, Jilin province, and Liangshan, Sichuan province, including B. gargarizans gargarizans and B. gararizans andrewsi, were collected. The UHPLC-LTQ-Orbitrap-MS combined with principal component analysis was used to compare the differences between two kinds of Bufonis Venenum. According to the limiting conditions of VIP>1, FC<0.5 or FC>2.0, and peak total area ratio>1%, 9 differential markers were determined, which were cinobufagin, cinobufotalin, arenobufagin, resibufogenin, scillaredin A, resibufagin, 3-(N-suberoylargininyl)-arenobufagin, 3-(N-suberoylargininyl)-marinobufagin, and 3-(N-suberoylargininyl)-resibufogenin. The content of 20 batches of Bufonis Venenum was determined according to the Chinese Pharmacopoeia(2020 edition) by high-performance liquid chromatography, and the 2 batches of Bufonis Venenum, CS7(8.99% of total content) and CS9(5.03% of total content), with the largest difference in the total content of the three quality control indexes of the Chinese Pharmacopoeia(bufalin, cinobufagin, and resibufogenin) were selected to evaluate their anti-liver tumor activity based on the zebrafish model. The tumor inhibition rates of the 2 batches were 38.06% and 45.29%, respectively, proving that only using the quality control indexes of the Chinese Pharmacopoeia as the value orientation of Bufonis Venenum market circulation was unreasonable. This research provides data support for the effective utilization of Bufonis Venenum resources and the establishment of a rational quality evaluation system of Bufonis Venenum.
Animals ; Zebrafish ; Bufanolides/analysis* ; Bufonidae ; Chromatography, High Pressure Liquid ; Quality Control ; Cell Line, Tumor

Based on mass spectrometry(MS)-guided separation strategy, compound 1 was obtained from the roots of Rhus chinensis. By comprehensive analysis of high resolution-electrospray ionization-mass spectrometry(HR-ESI-MS), nuclear magnetic resonance(NMR) data, and quantum chemical calculation of NMR(qcc-NMR) parameters, compound 1 was elucidated as rhuslactone, a 17-epi-dammarane triterpenoid with a rare 17α-side chain. An HPLC-ELSD method for its quantification in R. chinensis was established and adopted for the quantification of rhuslactone in different batches of R. chinensis. Rhuslactone displayed a good linear relationship within the range of 0.021 3-1.07 μmol·mL~(-1 )(r=0.997 6), and the average recovery was 99.34% [relative standard deviation(RSD) 2.9%). Moreover, the results of the evaluation test of the preventive effects of rhusalctone on coronary heart disease(CHD) and thrombosis showed that rhuslactone(0.11 nmol·mL~(-1)) significantly alleviated heart enlargement and venous congestion and increased cardiac output(CO), blood flow velocity(BFV), and heart rate, thereby reducing thrombus formation in zebrafish with CHD. The effects of rhuslactone on CO and BFV were superior to that of digoxin(1.02 nmol·mL~(-1)), and its effect on improving heart rate was comparable to that of digoxin. This study provides experimental references for the isolation, identification, quality control, and application of rhuslactone from R. chinensis against CHD. It is worth mentioning that this study has discussed some omissions in the determination of the stereochemistry of C-17 in dammarane triterpenoids in the present coursebook Chemistry of Chinese Medicine and some research papers, that is, the compound may be 17-epi-dammarane triterpenoid. This paper has also proposed steps for the establishment of C-17 stereochemistry.
Animals ; Zebrafish ; Rhus/chemistry* ; Triterpenes/analysis* ; Coronary Disease ; Thrombosis

This study aimed to evaluate the biological effect and mechanism of Vernonia anthelmintica Injection(VAI) on melanin accumulation. The in vivo depigmentation model was induced by propylthiouracil(PTU) in zebrafish, and the effect of VAI on melanin accumulation was evaluated based on the in vitro B16F10 cell model. The chemical composition of VAI was identified according to the high-performance liquid chromatography quadrupole-time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS). Network pharmaco-logy was applied to predict potential targets and pathways of VAI. A "VAI component-target-pathway" network was established, and the pharmacodynamic molecules were screened out based on the topological characteristics of the network. The binding of active molecules to key targets was verified by molecular docking. The results showed that VAI promoted tyrosinase activity and melanin production in B16F10 cells in a dose-and time-dependent manner and could restore the melanin in the body of the zebrafish model. Fifty-six compounds were identified from VAI, including flavonoids(15/56), terpenoids(10/56), phenolic acids(9/56), fatty acids(9/56), steroids(6/56), and others(7/56). Network pharmacological analysis screened four potential quality markers, including apigenin, chrysoeriol, syringaresinol, and butein, involving 61 targets and 65 pathways, and molecular docking verified their binding to TYR, NFE2L2, CASP3, MAPK1, MAPK8, and MAPK14. It was found that the mRNA expression of MITF, TYR, TYRP1, and DCT in B16F10 cells was promoted. By UPLC-Q-TOF-MS and network pharmacology, this study determined the material basis of VAI against vitiligo, screened apigenin, chrysoeriol, syringaresinol, and butein as the quality markers of VAI, and verified the efficacy and internal mechanism of melanogenesis, providing a basis for quality control and further clinical research.
Animals ; Vernonia/chemistry* ; Melanins/metabolism* ; Zebrafish/metabolism* ; Network Pharmacology ; Molecular Docking Simulation ; Apigenin/pharmacology* ; Drugs, Chinese Herbal/pharmacology* ; Chromatography, High Pressure Liquid

OBJECTIVE: To investigate the anti-angiogenic activity of Kunxian Capsule (KX) extract and explore the underlying molecular mechanism using zebrafish. METHODS: The KX extract was prepared with 5.0 g in 100 mL of 40% methanol followed by ultrasonication and freeze drying. Freeze dried KX extract of 10.00 mg was used as test stock solution. Triptolide and icariin, the key bioactive compounds of KX were analyzed using ultra-high performance liquid chromatography. The transgenic zebrafish Tg(flk1:GFP) embryos were dechorionated at 20-h post fertilization (hpf) and treated with PTK 787, and 3.5, 7, 14 and 21 µg/mL of KX extract, respectively. After 24-h post exposure (hpe), mortality and malformation (%), intersegmental vessels (ISV) formation, and mRNA expression level of angiogenic pathway genes including phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), extracellular signal-regulated kinases (ERKs), mitogen-activated protein kinase (MAPK), vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF-2) were determined. Further, the embryos at 72 hpf were treated with KX extract to observe the development of sub-intestinal vein (SIV) after 24 hpe. RESULTS: The chromatographic analysis of test stock solution of KX extract showed that triptolide and icariin was found as 0.089 mg/g and 48.74 mg/g, respectively, which met the requirements of the national drug standards. In zebrafish larvae experiment, KX extract significantly inhibited the ISV (P<0.01) and SIV formation (P<0.05). Besides, the mRNA expression analysis showed that KX extract could significantly suppress the expressions of PI3K and AKT, thereby inhibiting the mRNA levels of ERKs and MAPK. Moreover, the downstream signaling cascade affected the expression of VEGF and its receptors (VEGFR and VEGFR-2). FGF-2, a strong angiogenic factor, was also down-regulated by KX treatment in zebrafish larvae. CONCLUSION KX extract exhibited anti-angiogenic effects in zebrafish embryos by regulating PI3K/AKT-MAPK-VEGF pathway and showed promising potential for RA treatment.
Animals ; Fibroblast Growth Factor 2 ; Human Umbilical Vein Endothelial Cells ; Mitogen-Activated Protein Kinases/metabolism* ; Phosphatidylinositol 3-Kinase ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Zebrafish

OBJECTIVE: To evaluate toxicity of raw extract of Panax notoginseng (rPN) and decocted extract of PN (dPN) by a toxicological assay using zebrafish larvae, and explore the mechanism by RNA sequencing assay. METHODS: Zebrafish larvae was used to evaluate acute toxicity of PN in two forms: rPN and dPN. Three doses (0.5, 1.5, and 5.0 µ g/mL) of dPN were used to treat zebrafishes for evaluating the developmental toxicity. Behavior abnormalities, body weight, body length and number of vertebral roots were used as specific phenotypic endpoints. RNA sequencing (RNA-seq) assay was applied to clarify the mechanism of acute toxicity, followed by real time PCR (qPCR) for verification. High performance liquid chromatography analysis was performed to determine the chemoprofile of this herb. RESULTS: The acute toxicity result showed that rPN exerted higher acute toxicity than dPN in inducing death of larval zebrafishes (P<0.01). After daily oral intake for 21 days, dPN at doses of 0.5, 1.5 and 5.0 µ g/mL decreased the body weight, body length, and vertebral number of larval zebrafishes, indicating developmental toxicity of dPN. No other adverse outcome was observed during the experimental period. RNA-seq data revealed 38 genes differentially expressed in dPN-treated zebrafishes, of which carboxypeptidase A1 (cpa1) and opioid growth factor receptor-like 2 (ogfrl2) were identified as functional genes in regulating body development of zebrafishes. qPCR data showed that dPN significantly down-regulated the mRNA expressions of cpa1 and ogfrl2 (both P<0.01), verifying cpa1 and ogfrl2 as target genes for dPN. CONCLUSION This report uncovers the developmental toxicity of dPN, suggesting potential risk of its clinical application in children.
Animals ; Zebrafish/genetics* ; Saponins/pharmacology* ; Panax notoginseng/chemistry* ; Larva ; Sequence Analysis, RNA

Accurate and efficient methods for identifying and tracking each animal in a group are needed to study complex behaviors and social interactions. Traditional tracking methods (e.g., marking each animal with dye or surgically implanting microchips) can be invasive and may have an impact on the social behavior being measured. To overcome these shortcomings, video-based methods for tracking unmarked animals, such as fruit flies and zebrafish, have been developed. However, tracking individual mice in a group remains a challenging problem because of their flexible body and complicated interaction patterns. In this study, we report the development of a multi-object tracker for mice that uses the Faster region-based convolutional neural network (R-CNN) deep learning algorithm with geometric transformations in combination with multi-camera/multi-image fusion technology. The system successfully tracked every individual in groups of unmarked mice and was applied to investigate chasing behavior. The proposed system constitutes a step forward in the noninvasive tracking of individual mice engaged in social behavior.
Animals ; Mice ; Deep Learning ; Zebrafish ; Algorithms ; Neural Networks, Computer ; Social Behavior

Evading or escaping from predators is one of the most crucial issues for survival across the animal kingdom. The timely detection of predators and the initiation of appropriate fight-or-flight responses are innate capabilities of the nervous system. Here we review recent progress in our understanding of innate visually-triggered defensive behaviors and the underlying neural circuit mechanisms, and a comparison among vinegar flies, zebrafish, and mice is included. This overview covers the anatomical and functional aspects of the neural circuits involved in this process, including visual threat processing and identification, the selection of appropriate behavioral responses, and the initiation of these innate defensive behaviors. The emphasis of this review is on the early stages of this pathway, namely, threat identification from complex visual inputs and how behavioral choices are influenced by differences in visual threats. We also briefly cover how the innate defensive response is processed centrally. Based on these summaries, we discuss coding strategies for visual threats and propose a common prototypical pathway for rapid innate defensive responses.
Mice ; Animals ; Zebrafish ; Neurons/physiology* ; Visual Perception/physiology*

Predatory hunting is an important type of innate behavior evolutionarily conserved across the animal kingdom. It is typically composed of a set of sequential actions, including prey search, pursuit, attack, and consumption. This behavior is subject to control by the nervous system. Early studies used toads as a model to probe the neuroethology of hunting, which led to the proposal of a sensory-triggered release mechanism for hunting actions. More recent studies have used genetically-trackable zebrafish and rodents and have made breakthrough discoveries in the neuroethology and neurocircuits underlying this behavior. Here, we review the sophisticated neurocircuitry involved in hunting and summarize the detailed mechanism for the circuitry to encode various aspects of hunting neuroethology, including sensory processing, sensorimotor transformation, motivation, and sequential encoding of hunting actions. We also discuss the overlapping brain circuits for hunting and feeding and point out the limitations of current studies. We propose that hunting is an ideal behavioral paradigm in which to study the neuroethology of motivated behaviors, which may shed new light on epidemic disorders, including binge-eating, obesity, and obsessive-compulsive disorders.
Animals ; Zebrafish ; Hunting ; Predatory Behavior/physiology* ; Neurons/physiology* ; Motivation

Mammals exhibit limited heart regeneration ability, which can lead to heart failure after myocardial infarction. In contrast, zebrafish exhibit remarkable cardiac regeneration capacity. Several cell types and signaling pathways have been reported to participate in this process. However, a comprehensive analysis of how different cells and signals interact and coordinate to regulate cardiac regeneration is unavailable. We collected major cardiac cell types from zebrafish and performed high-precision single-cell transcriptome analyses during both development and post-injury regeneration. We revealed the cellular heterogeneity as well as the molecular progress of cardiomyocytes during these processes, and identified a subtype of atrial cardiomyocyte exhibiting a stem-like state which may transdifferentiate into ventricular cardiomyocytes during regeneration. Furthermore, we identified a regeneration-induced cell (RIC) population in the epicardium-derived cells (EPDC), and demonstrated Angiopoietin 4 (Angpt4) as a specific regulator of heart regeneration. angpt4 expression is specifically and transiently activated in RIC, which initiates a signaling cascade from EPDC to endocardium through the Tie2-MAPK pathway, and further induces activation of cathepsin K in cardiomyocytes through RA signaling. Loss of angpt4 leads to defects in scar tissue resolution and cardiomyocyte proliferation, while overexpression of angpt4 accelerates regeneration. Furthermore, we found that ANGPT4 could enhance proliferation of neonatal rat cardiomyocytes, and promote cardiac repair in mice after myocardial infarction, indicating that the function of Angpt4 is conserved in mammals. Our study provides a mechanistic understanding of heart regeneration at single-cell precision, identifies Angpt4 as a key regulator of cardiomyocyte proliferation and regeneration, and offers a novel therapeutic target for improved recovery after human heart injuries.
Humans ; Mice ; Rats ; Cell Proliferation ; Heart/physiology* ; Mammals ; Myocardial Infarction/metabolism* ; Myocytes, Cardiac/metabolism* ; Pericardium/metabolism* ; Single-Cell Analysis ; Zebrafish/metabolism*