Synthetic and Natural Radioprotective Agents: Recent Status and their Underlying Mechanism of Action

Various substances possessing radiation scavenging properties, known as radioprotectors, play a crucial role in shielding organisms from the harmful effects of ionizing radiation (IR) by preventing cellular damage caused by free radicals. Initially, synthetic radioprotectors were developed using thiol synthetic compounds. However, among these, only amifostine (WR-2721) underwent clinical testing as a radioprotector. Various composites with different chemical structures other than thiol compounds were also investigated. However, synthetic radioprotectors are known to be associated with severe side effects, which lead to an inclination towards natural substances. Plants and natural products have emerged as promising sources of radioprotectors, renowned for their non-toxic nature across a broad range of doses and their cost-effectiveness. Radioprotectors are employed in diverse pharmaceutical approaches to mitigate the toxicities induced by radiation. The present review encompasses a detailed account of various synthetic and naturally occurring compounds possessing radioprotective properties, and different investigations related to their radioprotective action, ranging from free radicals scavenging to gene therapy, have also been precisely covered. Numerous radioprotectors have different mechanisms of action, and have proven benefits of naturally occurring compounds over chemically synthesized ones.