Radioprotective Effect of Rosmarinus officinalis L (Rosemary) Essential Oil on Apoptosis, Necrosis and Mitotic Death of Human Peripheral Lymphocytes (PBMCs).

Background: Rosemary plant, with phenolic compounds, is known as an antioxidant herb and able to scavenge free radical agents in the biological environment; therefore, it is expected that the rosemary essential oil (R-EO) shows the radioprotective effect to protect individuals who are physically in contact with ionizing radiation. Objective: This study aimed to assess the radioprotective effect of R-EO on human peripheral blood mononuclear cells (PBMCs). Material and Methods: In this experimental study, the toxicity of the rosemary essential oil on PBMCs was assessed by the 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay. The cells were irradiated at 0. 25 and 200 cGy using a 6 MV X-ray linear accelerator. The survival, apoptosis, necrosis, and survival enhancement factors of cells were analyzed by MTT and flow cytometry analyses with a non-toxic concentration of the rosemary essential oil (IC10). Results: Irradiation of cells in the presence of R-EO caused a significant increase in cell survival compared with the control in both 25 and 200 cGy radiation doses. Also, the percentages of apoptosis and necrosis of cells showed a significant decrease compared with the control. Conclusion: Rosemary essential oil as a natural and non-toxic compound could show favorable radioprotective effects in such a way that significantly increases the survival rate and decreases the percentage of apoptosis and necrosis of PBMCs.