Abstract: Ionizing radiation is a type of energy released by atoms in the form of electromagnetic waves (X-rays and γ-rays) or particles (α, β, or neutrons) with energy greater than 12 eV sufficient to ionize atoms or molecules. Ionizing radiation can directly attack DNA, proteins, lipids and other biological macromolecules in the body, or indirectly damage cells by ionizing water molecules to produce a large number of free radicals, which in turn can cause damage to the human blood system, immune system, reproductive system and nervous system. Radioprotective agents are drugs that can reduce the systemic or local damage of ionizing radiation to the body when applied before or early after irradiation, thus contributing to the recovery of the damage. However, chemically synthesized radioprotective agents have deficiencies such as high research costs and toxic side effects. Therefore, the research and development of radioprotective agents derived from natural products has a promising future. In order to provide a reference for the research and development of new radiation protection agents based on active natural products, this paper introduces the mechanism of ionizing radiation damage to the human body and its hazards, and mainly discusses recent progress in research on the radiation protection effects of active natural products such as polysaccharides, polyphenols and peptides, and presents the problems of current research.

Key words: ionizing radiation, radiation damage, radioprotective agents, active natural products