Study on the Antiradiation Role of Melatonin: An Investigation on Induced Oxidative Stress in Mice by Radiomimetic Drug Cyclophosphamide

Clinical studies have demonstrated an altered pineal function in cancer patients. Owing to the documented antineoplastic activity of the pineal gland, these anomalies could have a prognostic significance. This study was carried out to monitor the effect of higher blood levels of melatonin, the most important pineal hormone, which could be applied in relation to the response to chemotherapy in human neoplasms. Cyclophosphamide is a commonly used chemotherapeutic drug and well-known mutagen and clastogen. It is an alkylating agent, producing highly active carbonium ion, which reacts with the extremely electron-rich area of the nucleic acids and proteins. The present study aimed to investigate the protective effect of melatonin against cyclophosphamide induced oxidative stress in mice tissues. Lipid peroxidation, Reduced glutathione (GSH), Glutathione disulphide (GSSG), Glutathione peroxidase (GSH-Px) and serum phosphatase level have taken as endpoints. Twenty days oral administration with melatonin (0.25 mg/Kg body weight) followed by an acute treatment with cyclophosphamide (75mg/kg b.w.) inhibited the radiomimetic drug-induced augmented level of lipid peroxidation, Blood GSSG and acid phosphatase. Cyclophosphamide induced depletion in the level of GSH, GSH-Px and alkaline phosphatase is ameliorated significantly by melatonin administration. The findings support the results showing melatonin as a free radical scavenger, and singlet oxygen quencher. Results clearly indicate the antioxidative properties of melatonin against the radiomimetic drug which could be effectively used selectively for the protection of normal tissue during chemotherapy.