RADIOPROTECTIVE POTENTIAL OF HERNIARIN: A NATURAL COUMARIN AGAINST IONIZING RADIATION-INDUCED OXIDATIVE AND GENOTOXIC INJURY

Abstract

The increasing use of ionizing radiation in diagnostic and therapeutic medicine has raised concern regarding radiation-induced injury to normal tissues, particularly the central nervous system. One of the earliest cellular responses to ionizing radiation is the generation of reactive oxygen and nitrogen species, leading to oxidative stress, lipid peroxidation, protein modification, mitochondrial dysfunction, DNA damage, genomic instability, inflammation, and cell death. These processes are particularly important in radiosensitive tissues and in the central nervous system, where radiation-induced oxidative and inflammatory injury may contribute to neurocognitive impairment, vascular dysfunction, and impaired neurogenesis. Therefore, increasing attention has been directed toward natural compounds with antioxidant, anti-inflammatory, and antigenotoxic properties that may reduce radiation-induced normal tissue injury. Herniarin, a naturally occurring simple coumarin, has attracted interest as a potential radioprotective compound. Coumarins are polyphenolic plant-derived compounds known for diverse pharmacological activities, including antioxidant, anti-inflammatory, cytoprotective, and antigenotoxic effects. Available experimental evidence suggests that herniarin and related coumarins may reduce oxidative DNA damage, limit genotoxicity, modulate endogenous antioxidant defence systems, and protect rapidly dividing cells from toxic injury. This review summarizes the biological mechanisms underlying ionizing radiation-induced oxidative and genotoxic damage and discusses the potential radioprotective role of herniarin, a natural coumarin compound. Although existing findings are promising, further in vivo and mechanistic studies are required to clarify optimal dose, timing, bioavailability, tissue-specific effects, and translational relevance.