Molecular hydrogen protects human lymphocyte AHH-1 cells against ¹²C⁶⁺ heavy ion radiation

Abstract

Purpose: To investigate the potential protective role of molecular hydrogen (H₂) against ¹²C⁶⁺ heavy ion radiation, which is a major hazard for space travel and has been also widely used in heavy ion radiotherapy.

Materials and methods: H₂ was dissolved in Roswell Park Memorial Institute (RPMI) 1640 medium under high pressure (0.4 Mpa) to a saturated level by using an apparatus produced by our department. A 2-[6-(4′-hydroxy) phenoxy-3H-xanthen-3-on-9-yl] benzoate (HPF) probe and a 2′,7′-Dichlorodihydrofluorescein diacetate (H2DCFH-DA) fluorescent dye were used to measure the intracellular reactive oxygen species (ROS) level. Cell apoptosis were determined by double-staining with Annexin V-fluorescein isothiocyanate (Annexin V-FITC) and propidium iodide (PI) as well as a Hoechst 33342 staining method alternatively. Subsequently, cell cycle analysis was performed using a PI staining method and the expression of apoptotic protein was examined by Western blot.

Results: In this study, we demonstrated H₂ reduced ROS level in Human lymphocyte AHH-1 cells as well as in the radiolysis of water. Our data also showed H₂ attenuated ¹²C⁶⁺ radiation- induced cell apoptosis and also alleviated radiation-induced G2/M cell cycle arrest. Heavy ion radiation-induced Caspase 3 activation was also inhibited by H₂ treatment.

Conclusion: In conclusion, these data showed that H₂ attenuated ¹²C⁶⁺ radiation-induced cell apoptosis through reducing the ROS level and modulating apoptotic molecules, thus indicating the potential of H₂ as a safe and effective radioprotectant.

Keywords::

• Heavy ion radiation
• free radicals
• apoptosis
• radioprotection