Antioxidant efficacy of natural compounds of vegetal origin in human immortalized kerattinocytes

Melanoma and nonmelanoma skin cancers are among the most prevalent cancers in the human population and exposure to ultraviolet (UV) light is well-established as the major etiologic factor. Free radicals are generated by normal physiologic processes, including aerobic metabolism and inflammatory response, but may inflict cellular damage when generation is increased and antioxidant defense mechanisms are overwhelmed. The hypothesis of an important role of free radicals in skin carcinogenesis is supported by several evidences including the finding that reactive oxygen species are generated following UV skin irradiation and that the natural antioxidant defences in skin are depleted after UV eposure. Moreover, it has been found that supplementation with antioxidants can inhibit skin carcinogenesis. These findings provide a promising rationale for the development of new antioxidant strategies in the prevention and therapy of skin cancer. In this paper, we evaluated the antioxidant efficacy of different natural compounds of vegetal origin in two different lines of immortalized human keratinocytes both in basal conditions and after exposure to hydrogen peroxide as free radical generator and we found that the compounds, although at different degree, were all able to inhibit reative oxygen species production in this cell model.