Study of radio protective effect of Thymus vulgaris essential oil against ionizing radiation on peripheral blood mononuclear cells (PBMCs)

Introduction: Today ionizing radiation (IR) plays an important role in medicine, both in diagnostic and therapeutic field. Doctors, medical staff and patients are all in danger of side effects of IR so there is a need to protect them against deleterious effects of ionizing radiation.  Thymus vulgaris has biological activities like antioxidant and antibacterial activity. Aim of this study is to determine the radio protection effect of essential oil of Thymus vulgaris on peripheral blood mononuclear cells (PBMCs). Materials and Methods: At the first step essential oil was obtained from Thymus vulgaris dried powder. Peripheral blood samples were collected from four volunteer donors. PBMCs were treated with non-toxic concentration of Thymus vulgaris essential oil in two groups of 24 hours before and 1 hour after exposure to both doses of 0.25 and 2 Gy of ionizing radiation.  After  72 hours viability percentage was determined by MTT assay. Results: Non-toxic concentration was obtained in 130 µg/ml. viability percentage in groups non- treated, treated 24 hours before and treated 1 hour after exposer to 0.25 Gy of ionizing radiation was 65%, 85% and 55% respectively. Also, viability percentage for the same groups that were exposed to 2 Gy of ionizing radiation was 75%, 105% and 65% respectively. Conclusion: As results demonstrate, it is an obvious radiation protection effect in groups that were treated with Thymus vulgaris 24 hours before exposure to ionizing radiation and also it is more specify in higher dose of radiation.