The beneficial effects of phytochemicals on human health have been
extensively addressed. The majority of this outcome derives from their
capability to function as antioxidants, thus the consumption of foods rich in
these compounds is considered an advisable preventive therapy in slowing
oxidative stress-mediated degenerative processes, such as those occurring during
aging. Nevertheless, high concentrations of redox-active compounds could
switch the antioxidant property to a pro-oxidant action leading to cell cycle
arrest and death. This aspect place phytochemicals as promising therapeutics
particularly for cancer prevention or treatment. Although their beneficial
properties are known from ancient times, only during the recent years the
molecular mechanisms underlying the anti-proliferative effects mediated by
garlic-derived organo-sulfur compounds (OSC) are going to be clarified, with
particular regard to what their pro-apoptotic features concerns. This chapter
discusses the main findings that have contributed to the comprehension of
OSC-mediated redox-dependent events governing growth arrest and apoptosis.
Particularly, we report the mechanisms through which OSC have been suggested
to generate reactive oxygen species and to modulate the redox state of specific
reactive cysteines. Both processes will be argued as necessary events in inducing
either irreversible damage to cellular macromolecules (e.g. DNA and
cytoskeleton proteins), or waves of signaling finally resulting in the activation of the apoptotic program. In this perspective, the classes of proteins which have been indicated to
represent the targets of OSC-mediated oxidative modifications, and to have a role in cellular redox response will be discussed