Psoralenbased

Psoralen-based compounds are a class of photosensitizing agents used in phototherapy, a treatment modality that combines light and a photosensitizing drug to induce specific biological responses. Psoralens are naturally occurring furanocoumarins found in various plants, such as bergamot, parsley, and celery. They are characterized by their ability to absorb ultraviolet (UV) light and form covalent bonds with DNA, leading to cross-linking of adjacent DNA strands.

The most commonly used psoralen in phototherapy is 8-methoxysoralen (8-MOP), which is a derivative of psoralen. When 8-MOP is applied topically to the skin and exposed to UV-A light (320-400 nm), it forms monoadducts and diadducts with DNA, leading to the formation of pyrimidine dimers. These dimers interfere with DNA replication and transcription, resulting in the inhibition of cell division and the induction of apoptosis.

Psoralen-based phototherapy is primarily used in the treatment of skin conditions, including psoriasis, vitiligo, and mycosis fungoides. It is also used in the treatment of certain eye conditions, such as uveitis and keratitis. The treatment typically involves the application of a psoralen-containing ointment or cream to the affected area, followed by exposure to UV-A light. The duration and intensity of the UV-A light exposure vary depending on the specific condition being treated.

Psoralen-based phototherapy is generally well-tolerated, with minimal side effects. However, it can cause photosensitivity reactions, including skin redness, itching, and blistering, in individuals who are not treated. Therefore, it is important to use appropriate sun protection measures during and after treatment. Additionally, psoralen-based phototherapy should be avoided in individuals with certain medical conditions, such as liver disease, and in those who are taking specific medications, such as rifampin.