THE APPLICATION OF ANTIOXIDANTS IN INVEST IGATIONS AND OPTIMIZATION OF PHOTOCHEMOTHERAPY

Psoralens (furocoumarins) are photosensitizers of the plant origin. Th ey are used in combination with near-ultraviolet (320-400 nm) light fo r the treatment of vitiligo, psoriasis, cutaneous T-cell lymphoma (CTC L), alopecia areata, eczema, and other skin diseases. Photobiological effects of psoralens in humans are numerous. They photosensitize eryth ema, hyperpigmentation, and skin aging, affect immune system, etc Mole cular mechanisms of photochemical reactions of psoralens and the subst rates modified are very numerous as well. The molecular basis and the relationships between different photobiological effects of psoralens r emain the subject of discussion. The use of antioxidants is an essenti al instrument for clearing up these problems as well as for improvemen t of photochemotherapy. It was found that antioxidants (alpha-tocopher ol, butylated hydroxytoluene, etc.) selectively inhibited the photoche mical stage of erythema and hyperpigmentation, but have no impact on t he post-irradiation stages of these processes. Evidently, the basis of these processes is the reactions of psoralen photosensitized oxidatio n of unsaturated lipids and the impairment of barrier functions of bio membranes, since the photochemical stage of these reactions is inhibit ed by antioxidant. At the same time, antioxidants did not inhibit the therapeutic effect in the cases of psoriasis and CTCL. Thus, antioxida nts can be used as a tool for improvement of psoralen photochemotherap y.