differentiate cells and organs, large number of progeny (approximately 300 by self-fertilization), short generation time (2–3 days)
and well-defined lifespan (2–3 weeks). More interestingly, its
genome is fully sequenced and genetic manipulation tools and
mutant collections are available. Despite significant differences
between C. elegans and animal vertebrates and mammals, 60–80%
of C. elegans genes have homologues in humans [3]. Another
important advantage to consider is that does not require committee
approvals for experimentation since it is not legally defined as an
animal according to European Union, Canada, or USA regarding
its use in laboratory tests [4–6]. One of the most interesting characteristics of this nematode is its use for testing the bioactivity of
food ingredients or complex food matrices [2]. In laboratory conditions C. elegans is grown on NGM (nematode growth medium)
plates which contain E. coli bacteria (OP50 strain), the major food
for the nematode. The compounds to be tested can be applied or
produced by the bacteria that are ingested, directly spread onto the
surface of plates, or added to the liquid medium when preparing
the plates [7]. The ingredients can be taken up by three different
processes: ingestion, through the cuticle, and via exposed sensory
neuronal cilia [3]. The ingestion of a compound depends on the
nematode satiety and availability in the medium being difficult to
control and it is a relatively slow process. Once the compounds
enter the intestinal lumen, they absorbed by intestinal cells and
distributed throughout the body [3]. Multiple models based on
C. elegans have been developed to study the effect of food ingredients and drugs in human diseases and degenerative processes such
as cancer [8], kidney diseases [9], neurodegenerative disorders
including Alzheimer’s disease and other tauopathies [10], obesity
[2, 11], mitochondrial disorders [12], diabetes [13], or aging
[2]. Most of these diseases, as well as the aging process, have in
common oxidative stress as an important contributing factor [13].
Several models are available for screening and testing functional
ingredients, being murine models and cell cultures the most widely
used although, due to their specific characteristics and advantages,
are gaining acceptance other models such as zebrafish or the nematode C. elegans. Cell cultures with human cells offer, as a main
advantage, a system with human biology and genetics, but in a
context far from the normal physiological situation with cell lines
originated from cancerous tissue growing outside the complete
organism. The murine model is the in vivo system most used in
preclinical research. Being a mammal is quite similar to humans, so
it increases confidence in the extrapolation of the results but, as a
counterpart, has great ethical issues and, due to its more complicated handle conditions, it is harder to use it in a routine screenings
or in certain experiments as related to aging [14]. On the other
hand, the use of C. elegans has advantages including rapid screenings with low cost, and could be very useful to obtain valuable
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Patricia Martorell et al.
and well-defined lifespan (2–3 weeks). More interestingly, its
genome is fully sequenced and genetic manipulation tools and
mutant collections are available. Despite significant differences
between C. elegans and animal vertebrates and mammals, 60–80%
of C. elegans genes have homologues in humans [3]. Another
important advantage to consider is that does not require committee
approvals for experimentation since it is not legally defined as an
animal according to European Union, Canada, or USA regarding
its use in laboratory tests [4–6]. One of the most interesting characteristics of this nematode is its use for testing the bioactivity of
food ingredients or complex food matrices [2]. In laboratory conditions C. elegans is grown on NGM (nematode growth medium)
plates which contain E. coli bacteria (OP50 strain), the major food
for the nematode. The compounds to be tested can be applied or
produced by the bacteria that are ingested, directly spread onto the
surface of plates, or added to the liquid medium when preparing
the plates [7]. The ingredients can be taken up by three different
processes: ingestion, through the cuticle, and via exposed sensory
neuronal cilia [3]. The ingestion of a compound depends on the
nematode satiety and availability in the medium being difficult to
control and it is a relatively slow process. Once the compounds
enter the intestinal lumen, they absorbed by intestinal cells and
distributed throughout the body [3]. Multiple models based on
C. elegans have been developed to study the effect of food ingredients and drugs in human diseases and degenerative processes such
as cancer [8], kidney diseases [9], neurodegenerative disorders
including Alzheimer’s disease and other tauopathies [10], obesity
[2, 11], mitochondrial disorders [12], diabetes [13], or aging
[2]. Most of these diseases, as well as the aging process, have in
common oxidative stress as an important contributing factor [13].
Several models are available for screening and testing functional
ingredients, being murine models and cell cultures the most widely
used although, due to their specific characteristics and advantages,
are gaining acceptance other models such as zebrafish or the nematode C. elegans. Cell cultures with human cells offer, as a main
advantage, a system with human biology and genetics, but in a
context far from the normal physiological situation with cell lines
originated from cancerous tissue growing outside the complete
organism. The murine model is the in vivo system most used in
preclinical research. Being a mammal is quite similar to humans, so
it increases confidence in the extrapolation of the results but, as a
counterpart, has great ethical issues and, due to its more complicated handle conditions, it is harder to use it in a routine screenings
or in certain experiments as related to aging [14]. On the other
hand, the use of C. elegans has advantages including rapid screenings with low cost, and could be very useful to obtain valuable
388
Patricia Martorell et al.