Analysis of structure-cytotoxicity in vitro relationship (SAR) for perfluorinated carboxylic acids

Perfluorinated carboxylic acids (PFAs) represent derivatives of naturally occurring compounds and have been widely used in various industrial fields for decades. They are known to be environmentally persistent. Thus far numerous reports have been focused on reproductive toxicity of PFAs in animals but few studies have been carried out on toxicity towards human cells. Viability tests were performed here at varying time-exposures on C-6-C-18 PFAs with human colon carcinoma (HCTI 16) cells. These cells were found earlier as the most useful line for in vitro assays. A chain length-EC50 dependence has been clearly observed. Estimated values of EC50 decreased with elongation of fluorocarbon chain (PFHxA > PFHpA > PFOA > PFNA > PFDA > PFDoA > PFTeDA). Further elongation (C-16 and C-18) did not deepen the effect but even partially reversed it. The effect was intensified after longer exposure (72 h); at relatively low 40 mu M PFTeDA, the viability decreased to similar to 50%. It seems that PFAs are not acutely toxic at the cellular level. Even so, however, they can trigger cell apoptosis, which is prominent in the case of myristic acid perfluorinated analogue. (c) 2007 Elsevier Ltd. All rights reserved.