Cellular DNA and ultraviolet-absorbing biomolecules (DNA/UV-biomolecules)

Cellular DNA and ultraviolet (UV)-absorbing biomolecules represent the primary biological targets for both solar radiation damage and photoprotective interventions. DNA is the most critical target, as the absorption of UVB and UVA radiation leads to the formation of mutagenic lesions such as cyclobutane pyrimidine dimers and oxidative base damage, which are precursors to skin cancers like melanoma and basal cell carcinoma. Other UV-absorbing biomolecules, including aromatic amino acids (tryptophan, tyrosine), melanin, and urocanic acid, act as endogenous chromophores that can either protect the cell by dissipating energy or contribute to damage through the generation of reactive oxygen species. In a pharmacological context, these molecules are the functional targets of sunscreens and phototherapeutic agents. Sunscreens utilize organic and inorganic filters to intercept UV radiation before it reaches these sensitive cellular targets, thereby preventing erythema and long-term genomic instability. Conversely, in treatments like PUVA (Psoralen plus UVA), drugs specifically interact with cellular DNA to induce controlled cross-linking, which is used to treat proliferative skin disorders such as psoriasis. Understanding the interaction between light and these biomolecules is essential for developing strategies to mitigate photoaging and UV-induced immunosuppression.

Other names

Genomic DNAEndogenous chromophoresCellular chromophoresBiological UV filtersNucleic acids and aromatic amino acids

Drugs targeting these molecules typically act by absorbing, reflecting, or scattering ultraviolet radiation to prevent direct damage to the DNA and other cellular components. In phototherapy, drugs like psoralens intercalate into the DNA and, upon UV activation, form covalent cross-links to inhibit rapid cell division.