Comparison of in vitro and in vivo acute toxicity assays in Etroplus suratensis (Bloch, 1790) and its three cell lines in relation to tannery effluent

Abstract

Cell lines of Etroplus suratensis established in our laboratory were evaluated for their potential use as screening tools for the ecotoxicological assessment of tannery effluent. The cytotoxic effect of tannery effluent in three cell lines derived from eye, kidney and gill tissue of E. suratensis was assessed using multiple endpoints such as Neutral Red (NR) assay, Coomassie Blue (CB) protein assay and Alamar Blue (AB) assay. Acute toxicity tests on fish were conducted by exposing E. suratensis for 96h to tannery effluent under static conditions. The toxic effect of tannery effluent on the survival of fish was found to be concentration and time dependent. The tannery effluent at the concentration of 15% caused 100% mortality at 96h whereas the lower concentration (0.5%) caused 13.33% mortality. The cytotoxicity of tannery effluent was found to be similar in the three cell lines tested, independent of the toxic endpoints employed. EC50 values, the effective concentration of tannery effluent resulting in 50% inhibition of cytotoxicity parameters after 48h exposure to tannery effluent were calculated for eye, kidney and gill cell lines using NR uptake, AB and cell protein assays. Statistical analysis revealed good correlation with r2=0.95–0.99 for all combinations between endpoints employed. Linear correlations between each in vitro EC50 and the in vivo LC50 data, were highly significant p<0.001 with r2=0.977, 0.968 and 0.906 for AB50, NR50, and CB50, respectively.