Citotoxic assessment of metals on BF-2 and RTG-2 fish cell lines using two alternative methods

Abstract

To evaluate the cytotoxicity of seven metals, two lines of fish cell culture, BF-2 and RTG-2 were used. The first cell line (BF-2). derived from the caudal fin portion of the trunk of bluegill sunfish and the second fish cell line, (RTG-2), derived from the gonadal tissues of the rainbow trout fish, both representing continental water organisms. Two in vitro alternative methods were carried out, neutral red uptake (NRU) assay and total cell protein content (TPC) assay. The toxicity regression lines and cytotoxicity values of the tested metals were estimated after 24 h of exposure period. According to the estimated midpoint cytotoxicity values (NRU50 and/or LC<inf>50</inf>) from the two in vitro techniques, the observed sequence of toxicity of metals on the two cell lines, was as follows: Hg²⁺ > Cd²⁺ > Cu²⁺ > Zn²⁺ > Co²⁺ > Ni²⁺ > Pb²⁺, respectively. The results of in vitro cytotoxicity showed good correlation with the published in vivo toxicity data of these metals on fishes. Finally, the comparison and correlation between the two in vitro techniques, and between the sensitivity of the two tested cell line have been done.