Photochemical Skin Injury Caused by Highly Oxygenated Compounds of Sosnovsky’s Hogweed

Sosnovsky’s hogweed (Heracleum sosnowskyi Manden.) is an invasive plant species widely distributed across Eastern Europe and Russia that poses a serious threat to human health due to its pronounced phototoxic properties. Contact with the plant sap, followed by exposure to ultraviolet radiation, frequently results in phytophotodermatitis characterized by erythema, blistering, ulceration, and long-lasting hyperpigmentation. The photochemical injuries are primarily attributed to highly oxygenated secondary metabolites, notably furanocoumarins, which act as potent photosensitizers and induce cellular and DNA damage upon UV activation. This review provides a comprehensive overview of the botanical distribution and invasiveness of H. sosnowskyi, the chemical composition of its biologically active metabolites, and the molecular mechanisms underlying hogweed-induced skin injuries. Particular emphasis is placed on the photochemical transformations of furanocoumarins, including psoralens and their photooxidation products, such as 1,2-dioxetanes, which generate reactive oxygen species and DNA crosslinks. In addition, the review discusses other compounds derived from hogweed biomass, including furan derivatives, aromatic compounds, fatty acids, sterols, and their oxidative products, which may contribute to phototoxic and cytotoxic effects. Clinical manifestations of hogweed burns, their classification, symptomatology, and current therapeutic approaches are critically analyzed, highlighting the lack of standardized treatment guidelines. By integrating chemical, biological, and clinical data, this review aims to elucidate the mechanisms of photochemical skin injury caused by H. sosnowskyi and to support the development of more effective preventive and therapeutic strategies.