The protective effect of oleuropein against radiation-induced cytotoxicity, apoptosis, and genetic damage in cultured human lymphocytes

The aim of this study was to evaluate the effects of oleuropein radiation protection and to find an effective radioprotector. Human mononuclear cells were treated with oleuropein at the concentration of 100 μM (optimum concentration), incubated for 24 h, and then exposed to 2 Gy gamma-rays. The anti-radiation effect of oleuropein was assessed by MTT assay, flow cytometry, comet assay, and micronucleus (MN) assay. It was found that pretreatment with oleuropein (25, 50, 75, 100, 200, 400, and 800 nM, and 1, 5, 10, 15, 20, 25, 30, 40, 50, 75, 100, 125, 150, 175, and 200 µM) significantly increased the percentage of cell viability compared to the irradiated group (<i>p</i> 50/24h dose was calculated as 2.9 Gy, whereas by 200, 150, 50, and 100 µM oleuropein prior to radiation (1, 2,and 4 Gy), radiation LD_50/24h increased to 3.36, 3.54, 3.81, and &gt;4 Gy, in that order. A very noticeable dose-modifying factor (DMF) of 1.16, 1.23, 1.31, and 1.72 was observed for 200, 150, 50, and 100 µM, in order. Therefore, 100 µM of oleuropein was selected as the desirable dose for radio-protection trial, and 2 Gy gamma-rays were used for further research. Human mononuclear cells treatment with oleuropein (100 µM) prior to 2 Gy gamma-rays significantly decreased apoptosis, genomic damage, and MN occurrence in human mononuclear caused by gamma-radiation (<i>p</i> The results revealed that oleuropein is able to significantly reduce cytotoxicity, apoptosis, genotoxic, and clastogenic effects of gamma-rays.