Evaluación del potencial citotóxico de tensioactivos mediante ensayo del MTT en distintas líneas celulares

Abstract

The MTT assay is one of the numerous in vitro methods, which have been proposed as alternative to the in vivo assays for determining the irritative potential of new compounds. The base of this cytotoxicity assay is that MTT or (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium) bromide, when reduced by mitochondrial dehydrogenases to the corresponding formazan, precipitates in colored crystals. These crystals dissolved in dimethylsulfoxide present an absorption peak at 540 nm. Therefore, the measure of absorbance is directly proportional to the number of viable cells. In this study the cytotoxic potential of 10 surfactants pertaining to the four different categories has been evaluated: Benzalkonium Chloride and 1-hexadecilpiridine Bromide (cationics), Sodium Lauryl Sulphate, Deoxycolic Acid and Jordapon (anionics), Triton X-100 and TWEEN 20 (nonionics) and Chaps, Chapso and Mirataine (amphoterics). Four cell lines of very different origin (MDCK, SIRC, V-79 and HT-29) have been employed in order to verify if there was any difference between them and the corneal epithelial cells. Treatments of 1, 4 and 20 hours have been carried out, with and without a recuperation period. The correlation with in vivo data and the relative cytotoxicity ranking of different compounds was maintained in all the cell lines and with all the treatments. None of the results obtained appear to be different from those refered in the literature in primary culture of rabbit corneal epithelial cells. Reversibility of the toxic effect has not been detected in any case.