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

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. This study aimed to assess the radioprotective effect of R-EO on human peripheral blood mononuclear cells (PBMCs). 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). 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. 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.