Investigation of shielding properties of gamma and neutrons in some natural radioprotective drugs

In radiation therapy, various radioprotective materials are used to protect normal cells from damage due to ionizing radiation. Natural products such as apigenin, bergenin, caffeine, chlorogenic acid, coniferyl aldehyde, curcumin, delphinidine, and quinic acid have been found to be good radioprotectors as they have low toxicities. In order to select the best natural radioprotector, it is essential to understand the interaction of gamma and neutrons with these radioprotectors and to determine radiation shielding parameters. The radiation parameters such as mass attenuation coefficient (MAC), effective atomic number (Zeff), equivalent atomic number (Zeq), effective electron density (Neff), exposure buildup factor (EBF), and energy absorption buildup factor (EABF) have been determined for the natural radioprotectors using EpiXs and NGCal software. The estimated results show that the Zeff values of selected radioprotectors are higher in the low-energy region and lower in the high-energy region, indicating that they are suitable for shielding low-energy gamma photons. Among selected natural radioprotectors, quinic acid is the best radioprotector for shielding thermal and fast neutrons. The relationship between MAF and Zeff/Neff has been established for the first time, and it has been found that MAF for thermal and fast neutrons decreases with an increase in the Zeff/Neff values of selected natural radioprotectors.