Title:Sulfur-containing Secondary Metabolites as Neuroprotective Agents
Volume: 27
Issue: 26
Author(s): Alessandro Venditti*Armandodoriano Bianco
Affiliation:
- Dipartimento di Chimica, Universita di Roma “La Sapienza”, Piazzale Aldo Moro 5, 00185, Rome,Italy
Keywords:
Sulfur-containing secondary metabolites, glucosinolates, dihydroasparagusic acid, serofendic acid, garlic,
hydrogen sulfide, neuroprotection.
Abstract: Sulfur-containing secondary metabolites are a relatively small group of substances
of plant origin. The present review is focused on their neuroprotective properties. The results
obtained in a series of in vitro and in vivo studies are reported. Among glucosinolates, the
wide class of compounds in the sulfur-containing metabolites, glucoraphanin, sulforaphane
and isothiocyanates proved to be the more studied in this context and showed interesting
properties as modulators of several systems involved in the pathogenesis of neurologic diseases
such as oxidative stress, inflammation and apoptosis. Allium sativum L. (garlic) is widely
known for its sulfur-containing components endowed with health-promoting activities and
its medicinal properties are known from ancient times. In recent studies, garlic components
proved active in neuroprotection due to the direct and indirect antioxidant properties, modulation
of apoptosis mediators and inhibiting the formation of amyloid protein. Dihydroasparagusic
acid, the first dimercaptanic compound isolated from a natural source, effectively inhibited
inflammatory and oxidative processes that are important factors for the etiopathogenesis
of neurodegenerative diseases, not only for its antioxidant and radical scavenging properties
but also because it may down-regulate the expression of several microglial-derived inflammatory
mediators. Serofendic acid represents a rare case of sulfur-containing animal-derived
secondary metabolite isolated from fetal calf serum extract. It proved effective in the suppression
of ROS generation and in the expression of several inflammatory and apoptosis mediators
and showed a cytotrophic property in astrocytes, promoting the stellation process. Lastly,
the properties of hydrogen sulfide were also reported since in recent times it has been recognized
as a signaling molecule and as a mediator in regulating neuron death or survival. It may
be produced endogenously from cysteine but may also be released by sulfur-containing secondary
metabolites, mainly from those present in garlic.
