The cytotoxic properties of malachite green are associated with the increased demethylase, aryl hydrocarbon hydroxylase and lipid peroxidation in primary cultures of Syrian hamster embryo cells.

Malachite green (MG), an industrial compound and potential environmental health hazard, is highly cytotoxic to mammalian cells in culture. In an attempt to define the biochemical basis, we have compared the cytotoxic effects and morphological alterations shown by MG in Syrian hamster embryo (SHE) cells with the levels of lipid peroxidation and the activities of aryl hydrocarbon hydroxylase, aminopyrine-N-demethylase, superoxide dismutase and catalase. Treatment of SHE cells with MG results into an induction of the mono-oxygenase system, lipid peroxidation and catalase in a dose-dependent way, indicating the formation of reactive free radicals. Accordingly, the possible involvement of reactive free radicals especially hydroxymethyl radicals in the observed high cytotoxicity due to exposure to MG is postulated.