Sulforaphane Cannot Protect Human Fibroblasts From Repeated, Short and Sublethal Treatments with Hydrogen Peroxide

13 January 2019
Lionetti et al.
A delicate balance of reactive oxygen species (ROS) exists inside the cell: when the
mechanisms that control the level of ROS fail, the cell is in an oxidative stress state, a condition
that can accelerate aging processes. To contrast the pro-aging effect of ROS, the supplementation
of antioxidants has been recently proposed. Sulforaphane (SFN) is an isothiocyanate isolated from
Brassica plants that has been shown to modulate many critical factors inside the cells helping to
counteract aging processes. In the present work, we exposed human dermal fibroblast to short,
sublethal and repeated treatments with hydrogen peroxide for eight days, without or in combination
with low concentration of SFN. Hydrogen peroxide treatments did not affect the oxidative status of
the cells, without any significant change of the intracellular ROS levels or the number of mitochondria
or thiols in total proteins. However, our regime promoted cell cycle progression and cell viability,
increased the anti-apoptotic factor survivin and increased DNA damage, measured as number of foci
positive for g-H2AX. On the other hand, the treatment with SFN alone seemed to exert a protective
effect, increasing the level of p53, which can block the expansion of possible DNA damaged cells.
However, continued exposure to SFN at this concentration could not protect the cells from stress
induced by hydrogen peroxide.