Tissue lipid peroxidation and glutathione-dependent enzyme status in patients with oral squamous cell carcinoma.

We examined the extent of lipid peroxidation and the status of reduced glutathione (GSH) and the GSH-dependent enzymes-glutathione peroxidase (GPx) and glutathione-S-transferase (GST)-in oral tumour tissues from 33 adult oral cancer patients and an equal number of age- and sex-matched normal subjects. Diminished lipid peroxidation in the oral tumour tissue was accompanied by a significant decrease in phospholipids and an increase in the cholesterol/phospholipid (C/P) ratio. The concentration of glutathione and the activities of GPx and GST were elevated in oral tumour tissues. These findings suggest that GSH- and GSH-dependent enzymes play a crucial role in tobacco-related tumourigenesis and may be considered as markers of carcinogen exposure.