Review Article
Antioxidant and Cell-Signaling Functions of Hydrogen Sulfide in the Central Nervous System
Figure 3
Role of hydrogen sulfide (H2S) as antioxidant in the neurodegenerative diseases Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), and amyotrophic lateral sclerosis (ALS). In AD, mitochondrial damage is caused by low levels of H2S in the cerebral cortex and cerebellum whereas H2S acts as antioxidant by GSH and amyloid beta-mediated oxidative damage. In PD, redox-sensitive proteins such as α-synuclein, parkin, and so on form Lewy bodies because of low levels of H2S whereas H2S imparts antioxidant functions by upregulation of antioxidant enzymes which inhibits reactive oxygen species (ROS) as well as lipid peroxidation products. In HD, elevated levels of ROS causes downregulation of activity in the striatum, hippocampus, and so on because of low supply of H2S whereas H2S acts as an antioxidant by reducing the excessive ROS. Lastly, in ALS, excessive amounts of proteins are downregulated because of low levels of H2S and H2S acts as antioxidant by proper regulation of antioxidant enzymes in ALS. In this ways, H2S imparts antioxidant functions by modulating oxidative stress conditions in the neurodegenerative diseases.