Critical role of hydrogen sulfide in the management of neurodegenerative disease.

Hydrogen sulfide has been known to humans for about 300 years and the previous studies emphasize only its toxic side effects. In the last two decennium, researchers have varied their perspectives and insights towards H₂S biology based on experimental findings. It has been found that H₂S is an endogenic gaseous signaling molecule in many organisms and plays a crucial role in many systems and diseases. Early reports suggest that H₂S as a neuromodulator influences calcium levels within the brain cells which ultimately control memory, learning, and cognition. It has also been observed that some complications in the pathogenesis of neurodegenerative diseases are due to anomalies in the biosynthesis and metabolism of H₂S. This review focuses on the role of H₂S in the pathophysiology of major neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease and Vascular dementia. H₂S was observed to have a protective role in the above-mentioned neurological conditions and the H₂S donor therapy may help in disease management. The H₂S gas displays a neuroprotective role and protects against cellular damage thereby declining the neurological conditions. Some studies have revealed that treatment with H₂S donors has improved neuronal damage, restored memory and cognition in animal models. In this review, we have discussed the role of H₂S donors as neuroprotective agents with examples of some of the natural and synthetic H₂S donors, and also briefly enumerated the molecules used to detect H₂S in neurodegenerative diseases.