DOSE-RESPONSE EFFECTS OF MALACHITE GREEN ON FREE-RADICAL FORMATION, LIPID-PEROXIDATION AND DNA-DAMAGE IN SYRIAN-HAMSTER EMBRYO CELLS AND THEIR MODULATION BY ANTIOXIDANTS
A. Panandiker et al., DOSE-RESPONSE EFFECTS OF MALACHITE GREEN ON FREE-RADICAL FORMATION, LIPID-PEROXIDATION AND DNA-DAMAGE IN SYRIAN-HAMSTER EMBRYO CELLS AND THEIR MODULATION BY ANTIOXIDANTS, Carcinogenesis, 15(11), 1994, pp. 2445-2448
Malachite green (MG), consisting of green crystals with a metallic lus
tre, is very soluble in water and is highly cytotoxic to mammalian cel
ls and also acts as a liver tumour promoter. In view of its industrial
importance and possible exposure to human beings, MG poses a potentia
l environmental health hazard. We have earlier reported the possible i
nvolvement of reactive free radicals in morphological transformation o
f Syrian hamster embryo (SHE) cells by MG. In this study we have studi
ed the dose-response effects of MG on free radical formation, lipid pe
roxidation and DNA damage in SHE cells. Electron spin resonance analys
is with 5,5-dimethyl-1-pyrroline-N-oxide as a spin-trapping agent was
used to study the production of free radicals from MG. Exposure of SHE
cells to MG demonstrated a dose-dependent increase in the generation
of free radicals, lipid peroxidation and DNA damage. Treatment of SHE
cells with antioxidant enzymes such as catalase (CAT) and glutathione
peroxidase (GPx) prior to MG exposure decreased lipid peroxidation and
DNA damage, with CAT being more effective than GPx. Since metabolism
of MG leads to the generation of free radicals, and CAT and GPx decrea
sed MG-induced lipid peroxidation and DNA damage, the present study co
nfirms the possible relationship between the genotoxicity of SHE cells
by MG and the involvement of reactive free radical formation.