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15th
World Congress Clinical Nutrition
19th
– 22nd September 2010 El Sokhna Resort - Egypt
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Copyright © 2010.
WCCN2010.COM
All rights reserved |
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Health promoting effects of
plant antioxidants: Molecular
mechanisms underlies the biological
activities of phytochemicals
Antonella Leone
National Research Council, Institute
of Sciences of Food Production Via
Prov.le Lecce-Monteroni, Italy
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The health benefit of plant-derived
foods is established and new
researches are identifying active
plant derived molecules among the
thousands phytochemicals. Some
phytochemicals are antioxidants and
have been proposed as effective
anticancer agents. Among them,
polyphenols and carotenoids, present
in different foods and beverages,
have retained attention in recent
years Polyphenols from grape seed
extracts (GSE) possess a broad
spectrum of chemo-protective
properties and lycopene, found in
tomatoes and other fruits, has been
proposed to modulate hormonal and
immune systems, metabolic pathways,
and gap junction intercellular
communication (GJIC). In animal
cells, GJIC has been implicated in
the cell growth control via adaptive
responses: differentiation,
proliferation and apoptosis. GJIC is
deficient in many human tumors and
its restoration or upregulation is
associated with decreased cell
proliferation. In the carcinogenesis
process, the reversible inhibition
of GJIC has been hypothesized to be
involved in the tumor promotion
phase.
Some innovative, safe and
environmentally-friendly processes,
based on supercritical carbon
dioxide (S-CO2) extraction and on
subcritical water extraction (SWE)
is developing for the production of
antioxidants from plant matrices.
GSE and new S-CO2-extracted
oleoresins obtained from tomato and
tomato added with grape seeds were
analysed for antioxidant activities
and biological properties on human
keratinocytes and human breast
cancer cell (MCF-7) cultures. Plant
extracts showed the ability to
enhance the GJIC and connexin 43
expression in human cell cultures,
and were able to completely overcome
the GJIC inhibition induced by the
tumor promoter HgCl2. The knowledge
of molecular mechanisms underlies
the phytochemical effect and the
availability of products with
potentially healthy properties
obtained from natural sources (e.g.,
tomato berries and waste winery
by-products), by environmentally
friendly methods, could lay new
basis for preventive nutrition.
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