Hydrogen Sulfide in Skin Diseases: A Novel Mediator and Therapeutic Target

Together with nitric oxide (NO) and carbon monoxide (CO), hydrogen sulfide (H(2)S) is now recognized as a vital gaseous transmitter. The ubiquitous distributions of H(2)S-producing enzymes and potent chemical reactivities of H(2)S in biological systems make H(2)S unique in its ability to regulate cellular and organ functions in both health and disease. Acting as an antioxidant, H(2)S can combat oxidative species such as reactive oxygen species (ROS) and reactive nitrogen species (RNS) and protect the skin from oxidative stress. The aberrant metabolism of H(2)S is involved in the pathogenesis of several skin diseases, such as vascular disorders, psoriasis, ulcers, pigment disorders, and melanoma. Furthermore, H(2)S donors and some H(2)S hybrids have been evaluated in many experimental models of human disease and have shown promising therapeutic results. In this review, we discuss recent advances in understanding H(2)S and its antioxidant effects on skin pathology, the roles of altered H(2)S metabolism in skin disorders, and the potential value of H(2)S as a therapeutic intervention in skin diseases.