Cytotoxic and clastogenic effects of benzyl isothiocyanate towards cultured mammalian cells.

Benzyl isothiocyanate (BITC), a compound found in cruciferous vegetables present in the human diet, has previously been shown to induce chromosome aberrations in an Indian muntjac cell line. The results of this study show that it also induces both chromosome aberrations and sister chromatid exchanges (SCEs) in Chinese hamster ovary (CHO) cells in the absence of an exogenous metabolic activation system and induces DNA strand breaks as measured by the single-cell gel electrophoresis assay. However, whereas it increased the number of aberrations four-fold, it was not able to raise SCE levels by more than 50% and there was a levelling-off in the dose-response curve. Whereas the survival curve of CHO cells exposed to BITC was linear in shape, that of the human colorectal adenocarcinoma cell line HT29 was found to fit the exponential model (with an alpha equivalent of 0.28 and a beta equivalent of 2.80, where the concentration of BITC is measured in micrograms/ml). This pattern of clastogenic and cytotoxic activities is reminiscent of that generated by ionizing radiation and certain radiomimetic chemotherapeutic agents.