Role of salivary and plasma melatonin levels in oral squamous cell carcinoma

The present research aims to look into the variations in levels of plasma and saliva melatonin with the sleep-wake cycle in healthy individuals and its correlation with the levels in oral squamous cell carcinoma (OSCC) patients and to explore the possibility of the use of plasma and saliva, as reliable, minimally-invasive/ non-invasive, and biofluids for measuring the levels of melatonin as biomarkers for the diagnosis of OSCC. This comparative case–control prospective study was conducted on histopathologically proven 10 patients suffering from OSCC (Group II) and 10 healthy individuals (Group I) belonging to the age group of 25–65 years. The antecubital fossa region was used to draw peripheral venous blood, which was then centrifuged, and the plasma was kept at −200C. Using the passive drool technique, approximately 5 mL of unstimulated saliva samples were obtained, and the samples were kept at −200C. Both the samples were assayed as early as possible. The result obtained was that the salivary and plasma melatonin levels were much higher during evening hours than morning interval in the healthy group (Group I). A similar trend was shown in Group II, compared to patients with OSCC, healthy patients have much higher levels of melatonin in their saliva and plasma. Hence, we conclude that the evaluation of the salivary melatonin level of patients suffering from OSCC may be considered reliable as well as non-invasive methods in the early diagnosis of OSCC. Saliva may be considered more advantageous over plasma for being non-invasive, less technique sensitive procedure, and having good patient compliance.