172 - Ascorbic acid increases cell death in fibroblast and VERO cultures after oxidative and thermic stress
Rivista: Riv Med Lab - JLM, Vol. 4, N. 3-4, 2003 (SIRSE Srl ed.)
L. Zanatta, M. Sandri, P. Arslan.
Background: Ascorbic acid has been considered to
act as a scavenger of free radicals generated in the
cell after oxidative stress. Cultured rat fibroblasts
and monkey kidney tumor cells (cell line VERO)
were subjected to oxidative and thermic stress in the
presence and absence of ascorbic acid in order to
directly test this action.
Materials and Methods: The cell viability was analyzed
by a cell proliferation assay (XTT), while cell
death was studied by in situ DNA nick/end labeling
(TUNEL), double vital Hoechst/Propidium iodide
staining and nuclear morphology.
Results: The incubation of the cells with hydrogen
peroxide for different times showed that after 2
hours the majority of the cells were dead and ascorbic
acid did not protect fibroblast and VERO cells
from this oxidative stress. The decrease of cell viability
is dependent on hydrogen peroxide concentration
and is not affected by the presence of increasing
concentrations of ascorbic acid. Necrotic cell death
occurs after a loss of cell membrane integrity without
nuclear shrinking and lack of labeling by
TUNEL. Similar results were obtained after inducing
a thermic stress.
Conclusions: Under the present experimental conditions
ascorbic acid did not protect the cells but
rather increased the effects of both the oxidative and
the thermic stress.