Topically applied vitamin C and cysteine derivatives protect against UVA-induced photodegradation of suprofen in ex vivo pigskin.

Exposure of the nonsteroidal anti-inflammatory drug suprofen (SUP) to UV-radiation results in the formation of radicals, reactive oxygen species (ROS), photodecarboxylated products and photoadducts with biomacromolecules. Using an ex vivo pigskin explant model, we investigated whether topical coapplication of the water-soluble antioxidants vitamin C (Lascorbic acid, ASC), N-acetyl-L-cysteine (NAC) or L-cysteine ethylester (CYSET) with SUP reduced ultraviolet A (UVA)-induced decomposition of SUP. UVA-induced changes in antioxidant bioavailability in the stratum corneum and epidermis were also studied.

Photoprotection by antioxidants against UVB-radiation-induced damage in pig skin organ culture.

Topically applied antioxidants constitute an important group of protective agents against skin damage induced by ultraviolet radiation. The current study was performed to investigate whether a recently developed ex vivo pig skin model was suitable for short-term studies of the mechanism(s) of UVB-radiation-induced skin damage; the protective effect of topical application of alpha-tocopherol, l-ascorbic acid, alpha-lipoic acid, glutathione ethylester and N-acetylcysteine was tested. Increasing doses of the antioxidants were applied topically on ex vivo pig skin explants and allowed to penetrate for 60 min.

Apoptosis in leukocytes induced by UVA in the presence of 8-methoxypsoralen, chlorpromazine or 4,6,4'-trimethylangelicin.

Although 8-methoxypsoralen (8-MOP) has been successfully used in extracorporeal photochemotherapy (ECP) of several T cell-mediated diseases, the exact mechanism of the drug therapeutic action has not been established. We have studied in vitro apoptotic activity of 8-MOP, and for comparison of 4,6,4'-trimethylangelicin (TMA) and chlorpromazine (CPZ) as alternative photosensitizers for potential use in photopheresis. However, while 8-MOP and CPZ are known for their immune suppressive activity, TMA does not exhibit such an activity in an animal model for ECP.