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

Abstract

Purpose

The aim of this study was to evaluate the effects of oleuropein radiation protection and to find an effective radioprotector.

Materials and Method

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.

Results

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 (p < .001). Moreover, oleuropein treatment with the above concentrations defined without gamma-ray did not show any cytotoxicity effect in human mononuclear cells. The LD_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 >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 (p < .001). Furthermore, treatment with oleuropein (100 µM) without radiation did not lead to apoptosis, genotoxicity, or clastogenic effects caused by oleuropein in human mononuclear cells.

Conclusion

The results revealed that oleuropein is able to significantly reduce cytotoxicity, apoptosis, genotoxic, and clastogenic effects of gamma-rays.

Keywords:

• Oleuropein
• human peripheral blood mononuclear cells
• MTT assay
• flow cytometry
• comet assay
• micronucleus (MN) assay

Acknowledgments

The authors gratefully acknowledge the Radiotherapy center physicians at Shohadaye Tajrish Hospitals, Shahid Beheshti, Tehran, Iran for providing radiation facility and Bone marrow transplant center at Taleghani Hospitals, Shahid Beheshti, Tehran, Iran for providing flow Cytometry facility. Fatemeh Amani gratefully acknowledges the financial assistance awarded by Razi Herbal Medicines Research Center (RHMRC) at Lorestan University of Medical Sciences, Khorramabad, Iran in the form of a Senior Research Fellowship to the first author.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Fatemeh Amani

Fatemeh Amani, MSc, is a Senior Researcher at the Radiation Technology Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Mehdi Allahbakhshian Farsani

Mehdi Allahbakhshian Farsani, PhD, is an Associate Professor of Laboratory Hematology at the Department of Hematology and Blood Banking and HSCT Research Center, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Mehrdad Gholami

Mehrdad Gholami, PhD, is an Associate Professor of Medical Physics at the Department of Medical Physics and Razi Herbal Medicines Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran.

Seyed Mahmoud Reza Aghamiri

Seyed Mahmoud Reza Aghamiri, PhD, is Professor of Radiation at the Radiation Medicine Department, Shahid Beheshti University, Tehran, Iran.

Mohsen Bakhshandeh

Mohsen Bakhshandeh, PhD, is an Associate Professor of Medical Physics at the Radiation Technology Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Mohammad Hossein Mohammadi

Mohammad Hossein Mohammadi, PhD, is an Assistant Professor of Hematology at the Department of Hematology and Blood Banking, and HSCT Research Center, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.