Plant Extracts and Plant-Derived Compounds: Promising Players in Countermeasure Strategy Against Radiological Exposure: A Review

Radiation exposure leads to several pathophysiological conditions, including oxidative damage, inflammationand fibrosis, thereby affecting the survival of organisms. This review explores the radiation countermeasureproperties of fourteen (14) plant extracts or plant-derived compounds against these cellular manifestations. It wasaimed at evaluating the possible role of plants or its constituents in radiation countermeasure strategy. All the 14plant extracts or compounds derived from it and considered in this review have shown some radioprotection indifferent in vivo, ex-vivo and or in vitro models of radiological injury. However, few have demonstrated advantagesover the others. C. majus possessing antioxidant, anti-inflammatory and immunomodulatory effects appearsto be promising in radioprotection. Its crude extracts as well as various alkaloids and flavonoids derived fromit, have shown to enhance survival rate in irradiated mice. Similarly, curcumin with its antioxidant and theability to ameliorate late effect of radiation exposure, combined with improvement in survival in experimentalanimal following irradiation, makes it another probable candidate against radiological injury. Furthermore,the extracts of P. hexandrum and P. kurroa in combine treatment regime, M. piperita, E. officinalis, A. sinensis,nutmeg, genistein and ginsan warrants further studies on their radioprotective potentials. However, one that hasreceived a lot of attention is the dietary flaxseed. The scavenging ability against radiation-induced free radicals,prevention of radiation-induced lipid peroxidation, reduction in radiation cachexia, level of inflammatorycytokines and fibrosis, are some of the remarkable characteristics of flaxseed in animal models of radiation injury.While countering the harmful effects of radiation exposure, it has shown its ability to enhance survival rate inexperimental animals. Further, flaxseed has been tested and found to be equally effective when administeredbefore or after irradiation, and against low doses (≤5 Gy) to the whole body or high doses (12-13.5 Gy) to thewhole thorax. This is particularly relevant since apart from the possibility of using it in pre-conditioning regimein radiotherapy, it could also be used during nuclear plant leakage/accidents and radiological terrorism, whichare not pre-determined scenarios. However, considering the infancy of the field of plant-based radioprotectors,all the above-mentioned plant extracts/plant-derived compounds deserves further stringent study in differentmodels of radiation injury.