Circadian rhythmicity of plasma lipid peroxidation and antioxidants in oral squamous cell carcinoma

S Manoharan, AA Baskar, T Manivasagam, P Subramanian
Correspondence: Dr P Subramanian, psub@rediffmail.com

ABSTRACT
Introduction Oral cancer is one of the leading cancers in India accounting for 30 to 40 percent of all cancers. Disturbances in lipid peroxidation and antioxidants status have been implicated in the pathogenesis of several cancers including oral cancer. However, circadian disturbances of oxidants and antioxidants in oral cancer patients were not reported.
Methods The levels of plasma thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and activity of glutathione peroxidase (GPx) in ten oral cancer patients and an equal number of age-matched healthy subjects were assayed at every 6 hour intervals using colorimetric methods and their circadian characteristics were analysed using Cosinorwin computer software programme.
Results Alterations in mesor, amplitude, acrophase and r value of the chosen parameters were noticed.
Discussion The desynchronisation of plasma thiobarbituric acid reactive substances and the altered circadian characteristics of antioxidants observed in this study, may deserve further investigation for the early diagnosis, prognosis and for the efficacy of cancer chronotherapy.

Keywords: oral cancer, lipid peroxidation, antioxidants, circadian rhythms
Singapore Med J 2005; 46(4): 184-188