Poster Session:
5th International Functional Food Symposium, Hong Kong, Mar 10 & 11, 2011
EVOLUTION of DIETARY ANTIOXIDANTS
Sebastiano Venturi and *Mattia Venturi,
Servizio di Igiene, ASL n. 1, Pennabilli (RN) Italy,
*Department of Oral Sciences, University of Bologna, Italy.
SUMMARY
We proposed that:
The evolution of oxygen-producing cells was
probably one of the most significant events in
the history of life. Oxygen is a potent oxidant
whose accumulation in terrestrial atmosphere
resulted from the development of
photosynthesis over three billion years ago, in
blue-green algae (Cyanobacteria), which
were the most primitive oxygenic
photosynthetic organisms. Brown algae
(seaweeds) accumulate inorganic iodine to
more than 30,000 times the concentration of
this element in seawater, up to levels as high
as 1-4 % of dry weight.
Protective endogenous antioxidant
enzymes and exogenous dietary
antioxidants helped to prevent oxidative
damage (1-2).
In particular, mineral inorganic antioxidants
present in the primitive sea, as some reduced
compounds of metalloproteins of Rubidium,
Vanadium, Zinc, Iron, Copper, Molybdenum,
Selenium and Iodine, which play an important
role in electron transfer and in redox chemical
reactions.
2 I- I2 + 2 e- (electrons) = - 0.54 Volt
2 I- + Peroxidase + H2O2 + 2 Tyrosine
2 Iodo-Tyrosine + H2O + 2 eand
2 e- + H2O2 + 2 H+ (of physiological
water-solution)
2 H2O
iodide acts as a primitive electrondonor, through peroxidase, and has
an ancestral antioxidant function in
all iodide-concentrating cells from
primitive marine algae to more
recent terrestrial vertebrates.
2 I- + Peroxidase + H2O2 +
Tyrosine, Histidine, Lipids,
Carbons Iodo-Compounds + H2O + 2 e(antioxidants)
Iodo-Compounds: Iodo-Tyrosine,
Iodo- Histidine, Iodo- Lipids,IodoCarbons
Antioxidant biochemical
mechanism of iodides:
the most ancient and the most
powerful natural antioxidant
mechanism of defence from
poisonous reactive oxygen
species.
(Venturi S., 1985; Küpper F. et al., 2008;
Packer L., 2008)
Most of these substances act in the cells as
essential trace-elements in redox and
antioxidant metalloenzymes.
When about 500 million years ago plants
and animals began to transfer from the sea
to rivers and land, environmental deficiency
of marine inorganic antioxidants and iodine,
was a challenge to the evolution of
terrestrial life (1).
Terrestrial plants slowly optimized the
production of “novel” endogenous organic
antioxidants such as ascorbic acid,
polyphenols, flavonoids, tocopherols etc. A
few of these appeared more recently, in the
last 200-50 million years ago, in fruits and
flowers of angiosperm plants. In fact
Angiosperms (the dominant type of plant
today) and most of their antioxidant
pigments evolved during the late Jurassic
period. Plants employ antioxidants to
defend their structures against reactive
oxygen species (ROS) produced during
photosynthesis (3), and formed a part of the
human healthy diet.
Chordates, the primitive vertebrates,
began to use also the “novel” thyroidal
follicles, as reservoir for iodine, and to use
the thyroxine in order to transport
antioxidant iodide. Iodide is one of the most
abundant electron-rich essential element in
the diet of marine and terrestrial organisms.
Iodide, which acts as a primitive electrondonor through peroxidase enzymes, has an
ancestral antioxidant function in all iodideconcentrating cells from primitive marine
algae to more recent terrestrial vertebrates
(2-3).
Recently, we hypothesized that in the
wide range of antioxidants, there might be
an “evolutionary hierarchy”, where the
most ancient might be more essential than
the recent antioxidants in the developing
stages of animal and human organisms (3).
E-mail: [email protected]
In the XIV Biennial Meeting of the
Society for Free Radical Research
International (18-22 October, 2008 –
Beijing, China)
Professor Lester Packer (USA), the
world's foremost antioxidant research
scientist, gave a general introductory talk
on the field of Oxidants and Antioxidants
in Biology :
“ The 2nd half of the 20th century
increasingly identified climatic conditions,
environmental oxidative stressors,
micronutrients, antioxidants, and lifestyle
as important in oxygen biology.”
“
Interestingly, the most powerful
natural antioxidant is inorganic free
iodine ions that acts in the unique
environment of the apoplast of brown
algae.
If iodine were inside the cell its powerful
antioxidant activity would totally prevent
redox signaling hence through evolution
iodine transport mechanisms necessarily
were developed.”
REFERENCES
1)- Venturi S. et al. (2000). Environmental
iodine deficiency: A challenge to the
evolution of terrestrial life? Thyroid,
10, 727–9.
2)- Küpper F.C. et al. (2008). Iodide
accumulation provides kelp with an
inorganic antioxidant impacting
atmospheric chemistry. Proc Natl
Acad Sci USA. 13, 105(19), 6954–8.
3)- Venturi S. and Venturi, M. (2007).
Evolution of Dietary Antioxidant
Defences. European EpiMarker,11(3), 1–12.
Iodine in Evolution
Over three billion years ago, blue-green algae were the first living Prokaryota to
produce oxygen, halocarbons (such as CH3I) in the atmosphere, and also
PUFAs in lipid membranes. About 500-600 million years ago, when also the
primitive brain evolved in marine animals, thyroid cells originated from primitive
gut in vertebrates, migrated and specialized in uptake and storage of iodocompounds in a novel follicular “thyroidal” structure, as a reservoir for iodine.
400-300 Mya some vertebrates evolved in amphibians and reptiles and
transferred to I-deficient land. In vertebrates, thyroid hormones became active in
the metamorphosis and thermogenesis for a better adaptation to terrestrial
environment.
Sequence of 123-iodide total-body scintiscans of a woman after intravenous injection of 123iodide (half-life: 13 hours); (from left) respectively at 30 minutes, and at 6, 20 and 48 hours. The highest and rapid
concentration of radio-iodide (in white) is evident in gastric mucosa of the stomach, salivary glands and oral mucosa. In
gastric mucosa of the stomach, 131-iodide (half-life: 8 days) persists in scintiscans for more than 72 hours. In the
thyroid, iodide-concentration is more progressive, as in a reservoir [from 1% (after 30 minutes) to 5.8 % (after 48
hours) of the total injected dose]. A high excretion of radio-iodide is observed in the urine.