Evaluation of drug toxicity is necessary for drug safety, but in vivo drug absorption is varied; therefore, a rapid, sensitive and reliable method for measuring drugs is needed. Zebrafish are acceptable drug toxicity screening models; we used these animals with a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method in a multiple reaction monitoring mode to quantify drug uptake in zebrafish to better estimate drug toxicity. Analytes were recovered from zebrafish homogenate by collecting supernatant. Measurements were confirmed for drugs in the range of 10–1,000 ng/mL. Four antibiotics with different polarities were tested to explore any correlation of drug polarity, absorption, and toxicity. Zebrafish at 3 days post-fertilization (dpf) absorbed more drug than those at 6 h post-fertilization (hpf), and different developmental periods appeared to be differentially sensitive to the same compound. By observing abnormal embryos and LD50 values, zebrafish embryos at 6 hpf were considered to be suitable for evaluating embryotoxicity. Also, larvae at 3 dpf were adapted to measure acute drug toxicity in adult mammals. Thus, we can exploit zebrafish to study drug toxicity and can reliably quantify drug uptake with LC-MS/MS. This approach will be helpful for future studies of toxicology in zebrafish.

Cephalosporins, derivatives of 7-aminocephalosporanic acid (7-ACA), are potent antibacterial agents. The toxicity prediction of these compounds is of considerable importance in new drug development. Zebrafish embryo toxicity testing was thought to be suitable for evaluation of the toxic properties of cephalosporins. Here, five kinds of cephalosporins and their isomers were used for investigation of the toxic functional groups of cephalosporins and for further evaluation of the efficacy of zebrafish embryo toxicity testing. Computational chemistry methods were also used to study the conformations of the stereoisomers of cephalosporins in aqueous solution to explore the relationship between the stereoisomers and the experimental results of toxicity tests on zebrafish embryos. Our results suggest that both the C-7 and C-3 substituents of cephalosporins are toxic functional groups. The toxic functional groups increase the toxic reaction of 7-ACA and can induce variable abnormal phenotypes in zebrafish embryo toxicity testing. The embryonic toxicities of cephalosporins were involved in organogenesis, mainly in the development of the cranial nerve, cardiovascular system, notochord and abdomen, and pigment formation; those tissues and organs are derived from ectoderm, mesoderm, and endoderm. The theoretical calculations showed a strong negative correlation between topological polar surface area (TPSA) values and the toxic effect, which indicated that molecular polarity may be crucial to the toxic effects of the isomers of cephalosporins. The concept of toxic functional groups may help us understand the safety differences of cephalosporins.

Drug-induced cardiotoxicity is a leading factor for drug withdrawals, and limits drug efficacy and clinical use. Therefore, new alternative animal models and methods for drug safety evaluation have been given great attention. Anthracyclines (ANTs) are widely prescribed anticancer agents that have a cumulative dose relationship with cardiotoxicity. We performed experiments to study the toxicity of ANTs in early developing zebrafish embryos, especially their effects on the heart. LC50 values for daunorubicin, pirarubicin, doxorubicin (DOX), epirubicin and DOX-liposome at 72 h post-fertilization were 122.7 μM, 111.9 μM, 31.2 μM, 108.3 μM and 55.8 μM, respectively. At the same time, zebrafish embryos were exposed to ANTs in three exposure stages and induced incomplete looping of the heart tube, pericardia edema and bradycardia in a dose-dependent manner, eventually leading to death. DOX caused the greatest heart defects in the treatment stages and its liposome reduced the effects on the heart, while daunorubicin produced the least toxicity. Genes and proteins related to heart development were also identified to be sensitive to ANT exposure and downregulated by ANTs. It revealed ANTs could disturb the heart formation and development. ANTs induced cardiotoxicity in zebrafish has similar effects in mammalian models, indicating that zebrafish may have a potential value for assessment of drug-induced developmental cardiotoxicity.

Hyperglycemia-triggered vascular abnormalities are the most serious complications of diabetes mellitus (DM). The major cause of vascular dysfunction in DM is endothelial injury and dysfunction associated with the reduced number and dysfunction of endothelial progenitor cells (EPCs). A major challenge is to identify key regulators of EPCs to restore DM-associated vascular dysfunction. We show that EPCs from heterozygous knockout Aggf1+/− mice presented with impairment of proliferation, migration, angiogenesis, and transendothelial migration as in hyperglycemic mice fed a high-fat diet (HFD) or db/db mice. The number of EPCs from Aggf1+/− mice was significantly reduced. Ex vivo, AGGF1 protein can fully reverse all damaging effects of hyperglycemia on EPCs. In vivo, transplantation of AGGF1-primed EPCs successfully restores blood flow and blocks tissue necrosis and ambulatory impairment in HFD-induced hyperglycemic mice or db/db mice with diabetic hindlimb ischemia. Mechanistically, AGGF1 activates AKT, reduces nuclear localization of Fyn, which increases the nuclear level of Nrf2 and expression of antioxidative genes, and inhibits reactive oxygen species generation. These results suggest that Aggf1 is required for essential function of EPCs, AGGF1 fully reverses the damaging effects of hyperglycemia on EPCs, and AGGF1 priming of EPCs is a novel treatment modality for vascular complications in DM.