Oxidative stress in the pathogenesis of psoriasis

Psoriasis is a chronic immune-mediated hyperproliferative inflammatory skin disease in which a cytokine network concept is well established. Skin is a major target of oxidative stress mainly due to reactive oxygen species (ROS) originating from the environment and skin metabolism itself. Although endogenous antioxidants attenuate the harmful effects of ROS, increased or prolonged presence of free radicals can override ROS defense mechanisms and mediate numerous cellular responses that contribute to the development of a variety of skin disorders, including psoriasis. Regarding psoriasis, antioxidant strategies have proven to be beneficial therapeutics. The cellular signaling pathways such as mitogen-activated protein kinase/activator protein 1, nuclear factor kappa B, and Janus kinase-signal transducers and activators of transcription are known to be redox sensitive and proven to be involved in the progress of psoriasis. This review summarizes the current knowledge of the role of the redox system in regulating these signaling pathways related to the pathogenesis of psoriasis. (C) 2009 Elsevier Inc. All rights reserved.