Toxicology, 37 (1985) 225--232 Elsevier Scientific Publishers Ireland Ltd. CYTOTOXIC EFFECTS OF WHEAT GLIADIN-DERIVED PEPTIDES A. STAMMATIPAGANUZZI*, F. ZUCCO a, M. CARDELLI, I. DE ANGELIS, R. MATTEI, A. PINO, E. ROCCA and F. ZAMPAGLIONI Laboratorio di Tossicologia Comparata ed Ecotossicologia, Istituto Superiore di SanitY, Viale Regina Elena 299, 00161 Roma and aIstituto di Tecnologie Biomediche- C.N.R., Via Morgagni 30/E, 00161 Roma (Italy) (Received January 28th, 1985) {Accepted June 25th, 1985) SUMMARY The peptic-tryptic-cotazym® (PTC) digest, obtained from bread wheat gliadin by simulating in vivo protein digestion, was more active than the PTC- digest of durum wheat gliadin in reversibly inhibiting HEp-2 cell proliferation and in increasing cellular acid phosphatase. Colony-forming ability of the cells was not affected by treatment with both bread or durum wheat gliadin peptides. The peptic-tryptic (PT) digest of bread wheat gliadin also showed agglutinating activity of HEp-2 cells. Key words: Gliadin peptides; Cell culture; Cytotoxicity; Coeliac disease; Cell growth; Acid phosphatase INTRODUCTION From a previous study we showed [1] that the PTC<ligest obtained by submitting bread (hexaploid) wheat gliadin to sequential digestion with pepsin, trypsin and cotazym@ (crude extract of hog pancreas.}, reduced viability and affected morphology of HEp-2 and MRC-5 cell lines in a dose- and time- dependent manner. Moreover the HEp-2 tumoral epithelial cells were more sensitive to the toxic action of wheat gliadin peptides than other cell types [1,2]. When tested under identical experimental conditions, the PTC<ligest of durum (tetraploid) wheat gliadin did not show any effect at a morphologi- *To whom correspondence sbould be sent. Abbreviations: AP, acid phosphatase; CF, colony formation; PBS, phosphate buffered saline; PTC, peptic-tryptic-cotazym® ; PT, peptic-tryptic; SU, sigma unit. 0300-483X/85/$03.30 © 1985 Elsevier Scientific Publishers Ireland Ltd. Printed and Published in Ireland Ltd. 225