Our aim was to investigate the temporal patterns of lipid peroxidation byproducts [thiobarbituric acid reactive substances (TBARS)] and enzymatic antioxidants [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)] in 7,12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch carcinogensis. The levels of thiobarbituric acid reactive substances and the activities of antioxidant enzymes were assayed at 4 h intervals throughout the 24 h period using colorimetric methods. The Cosinorwin computer software program was used to analyse the characteristics of biochemical rhythms such as acrophase, amplitude and mesor etc., Delayed acrophase was noticed for lipid peroxides and antioxidant enzymes in hamsters with oral squamous cell carcinoma as compared to control animals. Elevated and declined mesor values for TBARS and enzymatic antioxidants, respectively were observed in cancer animals. The disrupted diurnal rhythms of TBARS and antioxidants observed in the present study reflected an alteration of circadian clock function for these biochemical variables in DMBA induced oral carcinogenesis.
