Are zebrafish larvae suitable for assessing the hepatotoxicity potential of drug candidates?

Abstract

Drug-induced liver injury (DILI) is poorly predicted by single-cell-based assays, probably because of the lack of physiological interactions with other cells within the liver. An intact whole liver system such as one present in zebrafish larvae could provide added value in a screening strategy for DILI; however, the possible occurrence of other organ toxicities and the immature larval stage of the zebrafish might complicate accurate and fast analysis. We investigated whether expression analysis of liver-specific fatty acid binding protein 10a (lfabp10a) was an appropriate endpoint for assessing hepatotoxic effects in zebrafish larvae. It was found that expression analysis of lfabp10a was a valid marker, as after treatment with hepatotoxicants, dose-response curves could be obtained and statistically significant abnormal lfabp10 expression levels correlated with hepatocellular histopathological changes in the liver. However, toxicity in other vital organs such as the heart could impact liver outgrowth and thus had to be assessed concurrently. Whether zebrafish larvae were suitable for assessing human relevant drug-induced hepatotoxicity was assessed with hepatotoxicants and non-hepatotoxicants that have been marketed for human use and classified according to their mechanism of toxicity. The zebrafish larva showed promising predictivity towards a number of mechanisms and was capable of distinguishing between hepatotoxic and non-hepatotoxic chemical analogues, thus implying its applicability as a potential screening model for DILI.

Evolution of Experimental Models of the Liver to Predict Human Drug Hepatotoxicity and Efficacy

“…A corollary example was recently published by Verstraelen and colleagues, 42 in which they evaluated the expression of 5 liver-specific genes (including 2 apoptosis, and 2 metabolism-related) following exposure with 5 known toxicants. Their results confirmed those of Mesens and colleagues 41 with L-FABP 10a and further documented that biomarker responses are compound-dependent, mechanism-dependent, and concentration-dependent. At the present time, the utility of biomarkers for prediction of toxicity appears to have potential in “fit-for-purpose” studies.…”

ZeGlobalTox: An Innovative Approach to Address Organ Drug Toxicity Using Zebrafish

“…Both are well known molecules producing liver injury (extensively reviewed in [24,25]), with steatosis as a major side-effect for ethanol and liver malfunction and necrosis of liver tissue as the main toxic effect from paracetamol. Both hepatotoxic effects have also been reported in zebrafish larvae [26,27,28,29] (Table 1). …”

“…Previous studies have shown the relevance of using zebrafish for predicting the possible impact of drugs in those three organs individually [21,29,50,51,52,53,54,55,56]. However, no previous studies have integrated the analysis of these three organ-toxicities in the same animal; a procedure that reduces animal usage, experimental time and costs, and the quantity of the tested compound.…”

Zebrafish as Toxicological model for screening and recapitulate human diseases

“…Furthermore, zebrafish embryos and larvae showed no or low biotransformation capacity of four human CYP-specific substrates, dextromethorphan, diclofenac, testosterone and midazolam [101] . In contrast, has been reported the larva as a promising tool capable of distinguishing between hepatotoxic and non-hepatotoxic chemical analogues, implying that it may be applied as a screening model for DILI [102] . Also a recent study has developed a new experimental procedure (ZeGlobalTox assay) that addresses the organ-specific toxicity of different drugs on zebrafish larvae (up to 5 dpf).…”