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by Sayer Ji
May 23, 2014
from
GreenMedInfo Website
Spanish version
A groundbreaking new study published in Molecular Nutrition &
Food Research titled, "Interspecies
Communication Between Plant and Mouse Gut Host Cells through Edible
Plant derived Exosome-like Nanoparticles," reveals a new
way that food components 'talk' to animal cells by regulating gene
expression and conferring significant therapeutic effects.
With the recent discovery that
non-coding microRNA's in food are capable of directly altering gene
expression within human physiology, [1] this new
study further concretizes the notion that the age old aphorism 'you
are what you eat' is now consistent with cutting edge molecular
biology.
Exosomes - The
'Missing Link' In How Plants and Animal Cells Communicate and
Collaborate
This is the first study of its kind to look at
the role of exosomes,
small vesicles secreted by plant and animal cells that participate
in intercellular communication, in interspecies (plant-animal)
communication.
The study explained the biological properties of exosomes as
follows:
"Exosomes are produced by a variety
of mammalian cells including immune, epithelial, and tumor cells. Exosomes play a role in intercellular communication and
can transport mRNA, miRNA, bioactive lipids, and proteins
between cells.
Upon contact, exosomes transfer
molecules that can render new properties and/or reprogram their
recipient cells."
While most of the research on exosomes
has focused on their role in pathological states such as tumor
promotion, they were recently found to play a key role in
stimulating regeneration within damaged cardiac tissue, [2]
and are known to be found in human breast milk, further underscoring
how irreplaceable it is vis-à-vis synthesized infant formula.
[3]
The New Study
The investigators isolated plant derived exosome-like nanoparticles
(EPDENs) from ginger, carrot, grape and grapefruit, and observed
their behavior in mammalian cells (mice).
They chose these commonly consumed edible fruits and vegetables
because,
"It is well established that a
plant-derived diet has great influence on regulation of
mammalian host cell homeostasis, in particular, cells in the
digestive system.
Deregulation of plant-derived diet regulated
host cell homeostasis leads to increased susceptibility to
infections, chronic inflammatory bowel diseases, and cancer."
They noted,
"the cellular and molecular
machinery regulating such interspecies mutualism between a
plant-derived diet and the mammalian gut is not fully defined."
Their new study aimed to gain new
insight into defining the mechanisms through which cross-kingdom
crosstalk occurs.
Plant Exosomes
Affect Mammalian Cells Intimately
After isolating and characterizing exosome-like nanoparticles from
all four edible plants, the researchers discovered they possessed
remarkable similarity in size and structure to mammalian-derived
exosomes.
Furthermore, the study showed "that
these exosome-like nanoparticles are taken up by intestinal
macrophages and stem cells, and have biological effects on the
recipient cells."
The biological effects were described as follows:
-
Ginger exosome-like
nanoparticles strongly induced heme oxygenase-1 (HO-1) and
IL-10 expressed in macrophages, an indication of
anti-inflammatory and antoxidant properties.
-
Fruit-derived exosome-like
nanoparticles including grape and grapefruit induced Wnt/TCF4
activation, which is a key component of the
anti-inflammatory response
-
All tested foods activated
nuclear translocation of Nrf2, a key regulator of the HO1
gene, which has an important role in anti-inflammation and
antioxidation; ginger was found to be most potent, followed
by grapefruit, carrot and grape
Notably, EPDENs were found to be
resistant to gastric and intestinal enzymatic digestion, further
indicating they are capable of exerting significant biological
effects by escaping digestive degradation, which has also been found
with lectins and microRNA's within edible foods.
The researchers discussed their results:
"Our findings show that exosome-like
nanoparticles are present in edible fruits and vegetables and
reveal a previously unrecognized strategy by which plants
communicate with mammalian cells via exosome-like nanoparticles
in the gut, and in particular intestinal macrophages and stem
cells.
We found that edible plants contain
large amounts of nanoparticles.
Like mammalian exosomes, further
characterization of the plant nanoparticles led to identifying
them as exosome-like nanoparticles based on the nanoparticles
being com- posed of proteins, lipids, and miRNAs.
EPDENs from different types of
plants have different biological effects on the recipient
mammalian cells.
This finding opens up a new avenue
to further study the molecular mechanisms underlying how the
plant kingdom crosstalks with mammalian cells such as intestinal
macrophages and stem cells via EPDENs.
This information may provide the
molecular basis of using multiple plant-derived agents for
better therapeutic effect than any single plant-derived agent."
They also offered that their results may
explain why those who consume a greater variety of edible plants are
healthier:
"It has been known for decades that
people eating a variety of edible plants daily are the
recipients of many beneficial health effects when compared to
subjects that ingest fewer types of edible plants.
Ingesting EPDENs from a variety of
fruits and vegetables daily would be expected to provide greater
beneficial effects for maintaining gut homeostasis than
ingesting EPDENs from single edible plant."
Discussion -
Deeper Implications of the Study
As part of the fascinating new fields of
epigenetics and
nutrigenomics, this new study's findings promise to expand the
relevance of food in the practice of medicine and the prevention of
disease.
We have crossed a critical threshold in
the past few decades where food can no longer considered simply as a
source of caloric content, minerals and vitamins, and building
blocks for the body-machine.
Rather, food carries very specific forms
of biologically meaningful information (literally 'to put form
into'), without which our genetic and epigenetic infrastructure
cannot function according to its intelligent design.
The discovery of plant-dervied exosome-mediated modulation of
fundamental mammalian cellular pathways, lends powerful support to
the concept that ancestral nutritional practices handed down for
countless generations are critical in maintaining our health.
With the advent of the post-industrial
diet, based largely on 'food-like' synthesized nutrition, and the
novel introduction of grain-based nutrition in only the past 500
generations, our present diet suffers from a series of profoundly
biological incompatible foods.
Millions of years of co-evolutionary processes have generated a wide
range of interspecies, cross-kingdom co-dependencies.
For instance, mammals and angiosperms
(which comprise about 250,000 species and include most of the
flowering plants that provide the modern world its diet) co-evolved
for at least 200 million years together, and are today two of the
most dominant forms of life on the planet.
The very molecular and informational
fabric of our bodies evolved to intimately depend on the presence of
various key food components in the human diet, and the absence of
others which may be detrimental to our health.
Food components like exosomes may be as
important to our health as vitamins and other classically defined
'nutrients,' and may even be more important in modulating a wide
range of complex genetic- and epigenetic-mediated cellular processes
within the body.
This may also explain the mystery of how
certain fruits, such as pomegranate, have been
found to replace the function of the mammalian ovary in an
ovariectomy induced models of premature aging.
While pomegranate is one of nature's
most concentrated source of bioidentical estrone, exosomes may be
the 'missing link' as to how a plant food can support complex
hormonal processes within the animal body, along with exerting such
a wide range of
additional therapeutic health effects.
This is all the more evidence with
plants like turmeric, which have
over 600 health benefits and has been found to
modulate the expression of thousands of genes simultaneously.
[4]
We believe that taken together, the
recent discoveries that,
-
microRNA's within foods like
rice can enter into our blood and tissue and regulate gene
expression
-
that double-stranded
RNAs within a wide range of commonly consumed foods have
molecular homology with thousands of human RNAs
(and are therefore capable of silencing them)
-
that
lectins also can directly activate nuclear machinery within
certain cells, the addition of exosome-mediated
gene modulation, lends further support to the concept that
the quality and types of food we consume carry as much
relevance in terms of 'biological destiny' as the DNA within
our genome
With exciting research now available,
the famous quote attributed to Thomas Edison rings truer
today than ever:
"The doctor of the future will give
no medication, but will interest his patients in the care of the
human frame, diet and in the cause and prevention of disease."
References
-
Lin Zhang -
Exogenous plant MIR168a specifically
targets mammalian LDLRAP1: evidence of cross-kingdom
regulation by microRNA Cell Research
(2012) 22:107–126.
doi:10.1038/cr.2011.158; published online 20 September 2011
-
Ahmed Gamal-Eldin Ibrahim, Ke
Cheng, Eduardo Marbán.
Exosomes as Critical Agents of Cardiac Regeneration
Triggered by Cell Therapy. Stem Cell Reports,
May 2014 DOI:
10.1016/j.stemcr.2014.04.006
-
Qi Zhou1, et al
-
Immune-related MicroRNAs are Abundant
in Breast Milk Exosomes Int J Biol
Sci 2012; 8(1):118-123. doi:10.7150/ijbs.8.118
-
Sreenivasan S, Thirumalai K,
Danda R, Krishnakumar S. -
Effect of curcumin on miRNA expression in human Y79
retinoblastoma cells. Curr Eye Res. 2012
May;37(5):421-8. doi: 10.3109/02713683.2011.647224. PubMed
PMID: 22510010.
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