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

Together with nitric oxide (NO) and carbon monoxide (CO), hydrogen sulfide (H2S) is now recognized as a vital gaseous transmitter. The ubiquitous distributions of H2S-producing enzymes and potent chemical reactivities of H2S in biological systems make H2S unique in its ability to regulate cellular and organ functions in both health and disease. Acting as an antioxidant, H2S 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 H2S is involved in the pathogenesis of several skin diseases, such as vascular disorders, psoriasis, ulcers, pigment disorders, and melanoma. Furthermore, H2S donors and some H2S 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 H2S and its antioxidant effects on skin pathology, the roles of altered H2S metabolism in skin disorders, and the potential value of H2S as a therapeutic intervention in skin diseases.