Photoprotective effect of sesamol on UVB-radiation induced oxidative stress in human blood lymphocytes in vitro

Normal lymphocytes are highly sensitive to the damaging effect of radiation and undergo cell death. In the present study, the photoprotective effect of sesamol, a constituent of sesame oil, has been examined in the UVB-(280-320nm) irradiated human blood lymphocytes. Lymphocytes pretreated with increasing concentrations of sesamol (1, 5 and 10μg/ml) for 30min, were irradiated and lipid peroxidation and antioxidant defense were examined. UVB-irradiated lymphocytes exhibited increased levels of lipid peroxidation and disturbances in antioxidant defense. Sesamol pretreatment resulted in significant reduction in lipid peroxidation marker, thiobarbituric acid reactive substances (TBARS). Further, antioxidants like reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) increased, in a dose-dependent manner, in sesamol pretreated and UVB-irradiated lymphocytes. The maximum dose of sesamol (10μg/ml) normalized the UVB induced lipid peroxidation, indicating the photoprotective effect of sesamol in irradiated lymphocytes.