Comparative Study of Condensed and Hydrolysable Tannins during Early Stages of Zebrafish Development

Abstract

In this study, we present data on the effects of condensed (CTs) and hydrolysable (HTs) tannins, polyphenols extracted from plants, at different concentrations on zebrafish development to identify the range of concentrations with toxic effects. Zebrafish embryos were exposed to CTs and HTs at two different concentration ranges (5.0, 10.0, 20.0 μgL-1 and 5.0, 10.0, 20.0 mgL-1) for 72 h. The toxicity parameters were observed up to 72 h of treatment. The uptake of CTs and HTs by zebrafish larvae was assessed by HPLC analysis. The qRT-PCR analysis was performed to evaluate gene expression of cd63, zhe1 and klf4, involved in the hatching process of zebrafish. CTs and HTs at 5.0, 10.0, and 20.0 μgL-1 were not toxic. On the contrary, at 5.0, 10.0, and 20.0 mgL-1 HTs induced a delayed in hatching starting from 48 h of treatment, while CTs showed a delayed in hatching mainly at 48h. The analysis of gene expression showed a down-regulation in the group exposed to HTs confirming the hatching data. We believe that this study is important to define the optimal doses of CTs and HTs, to be employed in different application fields such as chemical and animal feed industry, and medical science.