Solar-Light-Activated Photochemical Skin Injury Induced 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 solar ultraviolet (UV) radiation frequently results in phytophotodermatitis, which is characterized by erythema, blistering, ulceration, and persistent hyperpigmentation. The development of these photochemical injuries—most notably furanocoumarins—act as potent photosensitizers and induce cellular and DNA damage upon UV activation. This review provides an integrated overview of the geographical spread and invasiveness of H. sosnowskyi, the chemical composition of its biologically active metabolites, and the molecular mechanisms underlying hogweed-induced skin injury. 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 examines other compounds derived from hogweed biomass—including furan derivatives, aromatic compounds, fatty acids, sterols, and their oxidative products—that may contribute to phototoxic and cytotoxic effects. Clinical manifestations of hogweed-induced burns, their classification, symptomatology, and current therapeutic approaches are critically discussed, highlighting the absence of standardized treatment guidelines. Rather than serving as a purely clinical or botanical survey, this review frames Sosnovsky’s hogweed injury as a solar-light-activated photochemical hazard, tracing the sequence from environmental sunlight exposure through molecular photochemistry to biological tissue damage. By integrating chemical, biological, and dermatological perspectives, the review aims to clarify injury mechanisms and support the development of more effective preventive and mitigation strategies under real-world exposure conditions.