The biologic effect of hydrogen sulfide and its function in various diseases

INTRODUCTION: Hydrogen sulfide (H(2)S), a colorless, water soluble, flammable gas with a characteristic smell of rotten eggs, has been known as a highly toxic gas for several years. However, much like carbon monoxide (CO) and nitric oxide (NO), the initial negative perception of H(2)S has developed with the discovery that H(2)S is generated enzymatically in animals under normal conditions. With the result of this discovery, much more work is needed to elucidate the biologic effects of H(2)S. In recent years, its cytoprotective properties have been recognized in multiple organs and tissues. In particular, H(2)S plays important roles in combating oxidative species such as reactive oxygen species (ROS) and reactive nitrogen species (RNS) and protect the body from oxidative stress. Therefore, this review discusses the biologic effect of H(2)S and how it protects cells in various diseases by acting as an antioxidant that reduces excessive amounts of ROS and RNS. ETHICS AND DISSEMINATION: Ethical approval and informed consent are not required, as the study will be a literature review and will not involve direct contact with patients or alterations to patient care. CONCLUSION: H(2)S has been found to be cytoprotective in oxidative stress in a wide range of physiologic and pathologic conditions, an increasing number of therapeutic potentials of H(2)S also have been revealed. However, there is still much debate on the clear mechanism of action of H(2)S, so that the mechanisms of cell signaling that promote cellular survival and organ protection need to be further investigated to provide better H(2)S-based therapeutics.