Ultraviolet radiation (UVR) (UVR)

Ultraviolet (UV) radiation is a non-molecular physical target consisting of electromagnetic radiation with wavelengths between 100 and 400 nm, categorized into UVA, UVB, and UVC (WHO, 2023). While not a protein or enzyme, it serves as a critical therapeutic modality in dermatology, where controlled exposure is used to treat inflammatory skin diseases such as psoriasis and vitiligo by inducing T-cell apoptosis and local immunosuppression (StatPearls, 2023). Biologically, UV radiation is essential for the cutaneous synthesis of Vitamin D, but it also acts as a potent mutagen by inducing DNA lesions, primarily cyclobutane pyrimidine dimers (CPDs), which can lead to skin carcinogenesis if not repaired (D'Orazio et al., 2013). In pharmacology, UV radiation interacts with photosensitizing drugs like psoralens (e.g., methoxsalen) in photochemotherapy (PUVA) to cross-link DNA and inhibit rapid cell turnover (PubChem, 2024). Additionally, a vast class of protective agents, including chemical and physical sunscreens, are designed to intercept UV radiation before it reaches biological targets, thereby preventing photoaging and malignancy (NIH, 2022).

Other names

UV lightUltraviolet raysSolar radiationActinic radiationUVA/UVB/UVC

Ultraviolet radiation acts by delivering high-energy photons that are absorbed by cellular chromophores such as DNA, urocanic acid, and melanin. This absorption leads to the formation of DNA photoproducts like cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts, the generation of reactive oxygen species (ROS) through photosensitization, and the modulation of signaling pathways that regulate cell cycle, apoptosis, and cytokine production (D'Orazio et al., 2013; StatPearls, 2023).