Protective effects of isothiocyanates towards N-nitrosamine-induced DNA damage in the single-cell gel electrophoresis (SCGE)/HepG2 assay

✍ Scribed by Nuria Arranz; Ana I. Haza; Almudena García; Lennart Möller; Joseph Rafter; Paloma Morales

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 209 KB
• Volume: 26
• Category: Article
• ISSN: 0260-437X
• DOI: 10.1002/jat.1163

✦ Synopsis

Abstract

The aim of this study was to investigate the protective effect of isothiocyanates towards N‐nitrosamine‐induced DNA damage in the single‐cell gel electrophoresis (SCGE)/HepG2 assay. None of the isothiocyanates (ITCs) concentrations tested in the presence or absence of formamidopyrimidine‐DNA glycosylase (Fpg) caused DNA damage per se. Combined treatments of HepG2 cells with phenethyl isothiocyanate (PEITC), allyl isothiocyanate (AITC) or indol‐3‐carbinol (I3C) and N‐nitrosopyrrolidine (NPYR) or N‐nitrosodimethylamine (NDMA) reduced the genotoxic effects of the N‐nitrosamines in a dose‐dependent manner. The protective effect of the three ITCs tested was higher towards NPYR‐induced oxidative DNA damage than against NDMA. The greatest protective effect towards NPYR‐induced oxidative DNA damage was shown by I3C (1 µM, 79%) and by PEITC (1 µM, 67%) and I3C (1 µM, 61%) towards NDMA (in presence of Fpg enzyme). However, in absence of Fpg enzyme, AITC (1 µM, 72%) exerted the most drastic reduction towards NPYR‐induced oxidative DNA damage, and PEITC (1 µM, 55%) towards NDMA. Our results indicate that ITCs protect human‐derived cells against the DNA damaging effect of NPYR and NDMA, two carcinogenic compounds that occur in the environment. Copyright © 2006 John Wiley & Sons, Ltd.