Effects of C60, a Fullerene, on the Activities of Glutathione S-Transferase and Glutathione-Related Enzymes in Rodent and Human Livers

The effects of C60, a fullerene, on the activities of glutathione 5-transferase (GST), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) in rodent and human livers were investigated. the GST activity in rat liver towards frans-4-phenyl-3-buten-2-one and that in mouse liver towards ethacrynic acid were inhibited by C60- the GST activity towards 1,2-dichloro-4-nitrobenzene, isomerase activity of GST towards androst-5-ene-3,17-dione, GSH-Px activity and GR activity were not affected by C60 a kinetic study using purified mouse GST-π with ethacrynic acid (25-100 μM) as the substrate revealed that C60 was a non-competitive inhibitor of the enzyme with a Ki = 48.8 ± 0.25 μM and a Ki = 47.9 ±0.18 μM. However, C60 did not inhibit the activity of purified mouse GST-π towards l-chloro-2,4-dinitrobenzene. Thus, the inhibition by C60 appears to be substrate-specific. In human liver, C60 inhibited the GST activity towards ethacrynic acid, and moderately inhibited GSH-Px and GR activities.