The role of phytochemicals in prevention and control of chronic diseases

Abstract

Background: Overproduction of oxidants (reactive oxygen and nitrogen species) in human body can cause an imbalance and lead to oxidative damage to large biomolecules such as proteins, lipids and DNA (Deoxyribonucleic acid) which is responsible for the development of chronic diseases. Metabolic diseases are associated to our daily lifestyle, mostly unbalanced energy-rich diet lacking fiber and bioactive compounds such as micronutrients and phytochemicals. Scavenging of these oxidants is thought to be an effective measure to depress the level of oxidative stress. Adequate dietary intake of fruits and vegetables may have protective effects against a number of diseases due to the biological protective effects of phytochemicals in these foods. Methodology: The reviewed article was obtained by using search tools to search for studies done within the year 2013 to 2017. Key words such as phytochemicals, antioxidants, polyphenols, bioavailability and health were used in the searching. Studies were searched in journals such as PUBMED, Science direct and Mendeley desktop used in the writing and referencing of the article. Results: Antioxidants found in popularly consumed vegetables, including red beans, have been found to prevent diabetic complications. Healthy eating practices that emphasizes consumption of plant based foods plays vital roles in the prevention of chronic diseases such as cancer, Alzheimer, cataract, heart diseases, age related function decline and stroke. Conclusion: Health practitioners should emphasize consumption of plant based foods as per the recommendations since they play a big role in the prevention and control of chronic diseases that are of high prevalence now and affected people all over the world

Full text

THE ROLE OF PHYTOCHEMICALS IN PREVENTION AND CONTROL OF CHRONIC DISEASES
*,1Monicah Njambi Kibe, 2
Silvenus Konyole
5
Doreen Kathure and
1,2,3Department of
Nutritional Sciences
Muliro University of
4,5Departmen
t of Health Promotion and Sports Sciences, School of
Technology,
Masinde Muliro University of Science and Technology, Kakamega, Kenya
6Department of Health
Sciences, School of Epidemiology
ARTICLE INFO
ABSTRACT
Background:
cause an imbalance and lead to oxidative damage to large biomolecules such as proteins, li
DNA (Deoxyribonucleic acid) which is responsible for the development of chronic diseases.
Metabolic diseases are associated to our daily lifestyle, mostly unbalanced energy
fiber
and bioactive compounds such as micronutrients and
oxidants is thought to be an effective measure to depress the level of oxidative stress. Adequate
dietary intake of fruits and vegetables may have protective effects against a number of diseases due to
the biological pr
Methodology:
within the year 2013 to 2017. Key words such as phytochemicals, antioxidants, polyphenols
bioavailability and health were used in the searching. Studies were searched in journals such as
PUBMED, Science direct and Mendeley desktop used in the writing and referencing of the article.
Results:
to prevent diabetic complications. Healthy eating practices that emphasizes consumption of plant
based foods plays vital roles in the prevention of chronic diseases such as cancer, Alzheimer, cataract,
heart diseases,
Conclusion:
recommendations since they play a big role in the prevention and control of chronic diseases that are
of high prevalence
Copyright © 2017, Monicah Njambi Kibe et al.
This
unrestricted use, distribution, and reproduction in any
medium,
INTRODUCTION
Phytochemicals are bioactive non-
nutrient compounds in
fruits, vegetables, grains and other plants. So far, about 10,000
phytochemicals have been identified (
Zhang
main two antioxidant phytochemicals are polyphenol and
carotenoids. Natural polyphenol
are the most abundant
antioxidants in human diets and their radical scavenging
activities are related to substitution of hydroxyl group in the
aromatic rings of the phenols.
*Corresponding author: Monicah Njambi Kibe
,
Department of Nutritional Sciences,
School
Biomedical Sciences and Technology
, Masinde Muliro University of
Science and Technology, Kakamega, Kenya.
ISSN: 0975-833X
Vol.
Article History:
Received 14th September, 2017
Received in revised form
05th October, 2017
Accepted 25th November, 2017
Published online 27th December, 2017
Citation: Monicah Njambi Kibe, Silvenus Konyole
phytochemicals
in prevention and control of chronic diseases
Key words:
Phytochemicals,
Health, Flavonoids,
Antioxidants,
Polyphenols,
Chronic Diseases.
RESEARCH ARTICLE
THE ROLE OF PHYTOCHEMICALS IN PREVENTION AND CONTROL OF CHRONIC DISEASES
Silvenus Konyole
, 3Gordon Nguka, 4
Micky Olutende Oloo,
Doreen Kathure and
6Peter M. Wangari
Nutritional Sciences
, School of
Public Health Biomedical Sciences
Muliro University of
Science and Technology
, Kakamega, Kenya
t of Health Promotion and Sports Sciences, School of Public Health Bio
Masinde Muliro University of Science and Technology, Kakamega, Kenya
Sciences, School of Epidemiology
,
Jomo University Kenyatta of Agriculture and
Technology, Nairobi, Kenya
ABSTRACT
Background:
Overproduction of oxidants (reactive
oxygen and nitrogen species)
cause an imbalance and lead to oxidative damage to large biomolecules such as proteins, li
DNA (Deoxyribonucleic acid) which is responsible for the development of chronic diseases.
Metabolic diseases are associated to our daily lifestyle, mostly unbalanced energy
and bioactive compounds such as micronutrients and
phytochemicals. Scavenging of these
oxidants is thought to be an effective measure to depress the level of oxidative stress. Adequate
dietary intake of fruits and vegetables may have protective effects against a number of diseases due to
the biological pr
otective effects of phytochemicals in these foods.
Methodology: The reviewed article was obtained by using search tools to search for studies done
within the year 2013 to 2017. Key words such as phytochemicals, antioxidants, polyphenols
bioavailability and health were used in the searching. Studies were searched in journals such as
PUBMED, Science direct and Mendeley desktop used in the writing and referencing of the article.
Results:
Antioxidants found in popularly consumed vegetables,
including red beans, have been found
to prevent diabetic complications. Healthy eating practices that emphasizes consumption of plant
based foods plays vital roles in the prevention of chronic diseases such as cancer, Alzheimer, cataract,
heart diseases,
age related function decline and stroke.
Conclusion: Health practitioners should emphasize consumption of plant based foods as per the
recommendations since they play a big role in the prevention and control of chronic diseases that are
of high prevalence
now and affected people all over the world.
This
is an open access article distributed under the Creative
Commons
medium,
provided the original work is properly cited.
nutrient compounds in
fruits, vegetables, grains and other plants. So far, about 10,000
Zhang
et al., 2015). The
main two antioxidant phytochemicals are polyphenol and
are the most abundant
antioxidants in human diets and their radical scavenging
activities are related to substitution of hydroxyl group in the
,
School
of Public Health
, Masinde Muliro University of
Fruits with high phenolic content possess stronger antioxidant
activity (Zhang et al
., 2015
resveratrol,
curcumin and anthocyanin can reduce
inflammation via inhibition of prostaglandins production and
nuclear factor kB-
activity, enzyme inhibition as well as
cytokine production. Lycopene present in tomatoes improve
endothelial function of people with cardiova
Lycopene and β-
carotene inhibit cell proliferation, arrest cell
cycle, and increase apoptosis in human breast cancer cells
(Zhang et al., 2015)
, angiogenesis/ neovascularization which is
the development of new capillaries from existing and/
preexisting vascular network and plays role in repair of system.
Angiogenesis is a
an important step in wound healing and
some botanicals compounds have been found to modulate
angiogenesis and increase the rate of wound healing
2016). Fru
its, vegetables and other plant based foods are active
International Journal of Current Research
Vol.
9, Issue, 12, pp.62540-62543, December, 2017
Silvenus Konyole, Gordon Nguka, Micky Olutende Oloo, Doreen Kathure and Peter M. Wangari
in prevention and control of chronic diseases
”, International Journal of Current Research, 9, (12), 625
40
Available online at http://www.journalcra.com
z
THE ROLE OF PHYTOCHEMICALS IN PREVENTION AND CONTROL OF CHRONIC DISEASES
Micky Olutende Oloo,
Public Health Biomedical Sciences
and Technology. Masinde
, Kakamega, Kenya
Public Health Bio
medical Sciences and
Masinde Muliro University of Science and Technology, Kakamega, Kenya
Jomo University Kenyatta of Agriculture and
oxygen and nitrogen species)
in human body can
cause an imbalance and lead to oxidative damage to large biomolecules such as proteins, li
pids and
DNA (Deoxyribonucleic acid) which is responsible for the development of chronic diseases.
Metabolic diseases are associated to our daily lifestyle, mostly unbalanced energy
-rich diet lacking
phytochemicals. Scavenging of these
oxidants is thought to be an effective measure to depress the level of oxidative stress. Adequate
dietary intake of fruits and vegetables may have protective effects against a number of diseases due to
The reviewed article was obtained by using search tools to search for studies done
within the year 2013 to 2017. Key words such as phytochemicals, antioxidants, polyphenols
,
bioavailability and health were used in the searching. Studies were searched in journals such as
PUBMED, Science direct and Mendeley desktop used in the writing and referencing of the article.
including red beans, have been found
to prevent diabetic complications. Healthy eating practices that emphasizes consumption of plant
based foods plays vital roles in the prevention of chronic diseases such as cancer, Alzheimer, cataract,
Health practitioners should emphasize consumption of plant based foods as per the
recommendations since they play a big role in the prevention and control of chronic diseases that are
Commons
Attribution License, which permits
Fruits with high phenolic content possess stronger antioxidant
., 2015
). Phytochemicals including
curcumin and anthocyanin can reduce
inflammation via inhibition of prostaglandins production and
activity, enzyme inhibition as well as
cytokine production. Lycopene present in tomatoes improve
endothelial function of people with cardiova
scular disease.
carotene inhibit cell proliferation, arrest cell
cycle, and increase apoptosis in human breast cancer cells
, angiogenesis/ neovascularization which is
the development of new capillaries from existing and/
or from
preexisting vascular network and plays role in repair of system.
an important step in wound healing and
some botanicals compounds have been found to modulate
angiogenesis and increase the rate of wound healing
(Sharad,
its, vegetables and other plant based foods are active
INTERNATIONAL JOURNAL
OF CURRENT RESEARCH
Peter M. Wangari, 2017.
“The role of
40
-62543.

in bioactive phytochemicals that may provide desirable health
benefits towards reduction of chronic diseases (Liu, 2013).
Dietary phytochemicals or antioxidants have been shown to
have a role in the reduction of platelets aggregation,
modulation of cholesterol synthesis and absorption and lipid
profiles, reduction of blood pressure and anti-inflammation
(Yin et al., 2016). Phytochemicals plays anticancer, anti-
inflammatory and antioxidant roles by regulating specific
signalling pathways and molecular markers to inhibit the
occurrence of cancer (Yin et al., 2016). Phytochemicals protect
the skin by reducing inflammation and quenching free radicals
through the inhibition of NF-kB (nuclear factor kappa B). They
also affect other signaling pathways including; transformation
growth factor beta (TGF-β). Poor bioavailability of
phytochemicals may be due to their high intrinsic activity,
absorption, rapid metabolism and rapid elimination and
clearance from the body (Sharad, 2016). Fruits, vegetables and
beverages rich in carotenoids, isoflavones, phytosterols and
phytoestrogen delay the onset of atherosclerosis or act as a
chemoprotective agent by interacting the underlying
pathomechanisms. Phytochemicals exert their beneficial
effects by reducing circulating level of cholesterol or by
inhibiting lipid oxidation and others exhibit anti-inflammatory
and antiplatelet (Upadhyay, 2015). The systematic review was
aimed to find out what research has found out concerning the
role of phytochemicals on health. The idea of the research was
generated after the high burden of non-communicable diseases
while focusing on the 2025 Global targets.
METHODS
The reviewed article was obtained by using search tools to
search for studies done within the year 2013 to 2017. Key
words such as phytochemicals, antioxidants, polyphenols,
bioavailability and health were used in the searching. Studies
were searched in journals such as PUBMED, Science direct
and Mendeley desktop used in the writing and referencing of
the article.
RESULTS
Disease development and phytochemicals
Phytochemicals from fruits, vegetables, spices and herbs to
some extent have immunomodulatory and anti-inflammatory
activities in the context of brain injury (Corbi et al., 2016).
Epidemiological studies have shown that frequent consumption
of vegetables, fruits which contain abundant phytochemicals,
lowers the onset of some diseases (Murakami, 2013).
Flavonoids have notable anti-oxidant activity which plays a
major role in protection against UV light-induced oxidative
damage as well as antimicrobial and antifungal activities
(Murakami, 2013). Flavonoids possess properties such as anti-
mutagenic activity, reducing the risk of cardiovascular
diseases, anti-proliferative action on tumour cells,
atherosclerosis protection, radio-protective action, hormonal
repository in natural menopause women and antimicrobial
activity (Pace et al., 2014). Flavonoids possess antioxidant,
hypocholestrolemic, anti-inflammatory effects as well as
ability to modulate cell signaling and gene expression related
to disease development (Thilakarathna, 2013). Green tea
polyphenol epigallocatechin-3-gallate (EGCg) has exhibited
anti-oxidative, anti-inflammatory and chemopreventive
properties in many experimental studies (Murakami, 2013).
Polyphenol provide health benefit by elimination of free
radicals, protection and generation of dietary antioxidants such
as vitamin E, and chelation of pro-oxidant metals ( Pace et al.,
2014). Chronic, low-grade inflammation is one of the major
risk factors for brain aging. Phytochemicals present in
vegetables, fruits, herbs and spices have shown relevant
immunomodulatory and anti-inflammatory in the context of
brain aging (Corbi et al., 2016). Whole grains has been shown
to play a vital role in health. The specific effect of food
structure (increased satiety, glycemic response and reduced
transit time), antioxidant and anti-carcinogenic properties of
numerous bioactive compounds especially those in germ and
bran (minerals, trace elements, vitamins, carotenoids,
polyphenols) all of which play part in prevention of
pathogenesis (Fardet, 2010) Metabolic diseases are associated
to our daily lifestyle, mostly unbalanced energy-rich diet
lacking fibre and bioactive compounds such as micronutrients
and phytochemicals (Fardet, 2010).
Scavenging of these oxidants is thought to be an effective
measure to depress the level of oxidative stress (Zhang et al.,
2015). Chronic inflammation is another contributing factor to
development of chronic diseases cancer, cardiovascular
diseases and diabetes mellitus. Adequate dietary intake of
fruits and vegetables may have protective effects against
coleretal cancer due to the biological protective effects of
phytochemicals in these foods (Yin et al., 2016).
Phytochemicals possess antioxidants and free radical
scavenging abilities as well as anti-inflammatory activities
which are basis for health benefits such as anti-aging,
anticancer and protection against diabetes mellitus,
cardiovascular diseases, neurodegenerative diseases and
obesity (Zhang et al., 2015). Healthy eating practices that
emphasizes consumption of plant based foods plays vital roles
in the prevention of chronic diseases such as cancer,
Alzheimer, cataract, heart diseases, age related function
decline and stroke (Liu, 2013).
Phytochemicals health benefits
Curcumin
It’s a hydrophobic polyphenol derived from turmeric. Research
shows it has a potential in suppressing inflammation and
inhibiting the growth of neoplastic cells (11). Curcumin down
regulate the expression of survivin and (Insulin growth factor)
IGF-1 by activating the expression of p53 and reducing tumor
necrosis factorα (TNFα) levels leading to activation of
apoptotic signals (Li, 2015). Curcumin protects the skin by
quenching free radicals and reducing inflammation through
NF-Kb inhibition. Curcumin also act as pro-angiogenic agent
during wound healing and wound repair by regulating TGF-
β(2). This phytochemical has been reported to show low or no
toxicity. Curcumin has biological and physiological activities
such as anti-neurodegenerative, anti-inflammatory, anti-
Alzheimer disease, anti-cancer, anti-oxidative, anti-HIV
activities and anti-obesity (Murakami, 2013).
Allicin
A thiosulphinate present in crushed garlic (Allium sativum L.)
bulbs .An antioxidant organosulfur compound from garlic acid,
was found to prevent the cardiovascular system by inducing
vasorelaxation and alleviating cardiac hypertrophy,
angiogenesis, platelets aggregation, hyperlipidemia and
hyperglycemia (Zhang et al., 2015).
62541 Monicah Njambi Kibe et al. The role of phytochemicals in prevention and control of chronic diseases

Allicin is produced upon tissue breakdown from the non-
proteinogenic amino acid alliin(S-allylcysteine sulfoxide) in a
reaction catalyzed by enzyme alliinase. Being a thiosulphinate,
allicin is a reactive sulfur species (RSS) which undergoes a
redox reaction with thiol groups in glutathione and proteins
that is thought to be essential for its biological activity
(Borlinghaus et al., 2014). Allicin is physiologically active in
microbial, plant and mammalian cells. In cancer cells, allicin
induces cell death and inhibit cell proliferation. Garlic has
health promoting benefits by reduction of triacylglycerol total
and low density lipoprotein cholesterol concentration without
altering the HDL (High Density Lipoprotein) cholesterol levels
(Borlinghaus et al., 2014). Allicin and other thiosulphinates are
known to react with cysteine to enhance antimicrobial activity
(Wallock-richards et al., 2014). Allicin has a variety of health
promoting properties, for example, blood pressure lowering
and cholesterol lowering all of which have a positive effect in
the cardiovascular system (Borlinghaus et al., 2014). The
compounds formed from the decomposition of alliin play an
important role in the antioxidant, protecting against some
degenerative diseases and acting as antibacterial against
positive and negative gram bacteria (Prati et al., 2014).
Compounds of garlic prevent cholesterol from attaching on the
walls of the blood vessels and thus prevention of
cardiovascular diseases.
Resveratrol
Resveratrol (trans-3, 4’, 5- trihydroxystilbene) belong to the
stibene family of phenolic compounds that is found in pine,
nuts, berries especially in the skin of red berry. Resveratrol
can inhibit thrombocyte aggregation, lipid peroxidation thus
vasodilation, anti-inflammatory and anti-oxidation roles (Yin
et al., 2016). Resveratrol shows chemopreventive mechanism
in inhibition of the three stages of cancer development; tumor
initiation, promotion and progression (Murakami, 2013).
DISCUSSION
Polyphenols provide health benefits of several mechanisms,
including the elimination of free radicals, protection and
regeneration of other antioxidants and the chelation of pro-
oxidant metals, antibacterial, anticancer and immune
modulatory actions.Antioxidant activities of polyphenols like
flavonoids is by scavenging of oxidizing species, superoxide
union, hydroxyl radical and Peroxyl radical (Pace et al., 2014).
Frequent consumption of vegetables and fruits with abundant
phytochemicals lowers the risk of the onset of some diseases.
Phytochemicals has created significant effects in the
prevention of chronic diseases such as cancer, metabolic
disorders and cardiovascular impairment. Polyphenol alone or
in combination with other nutrients are believed to have health
benefits and has proved to have pivotal role in metabolic
abnormalities such as dyslipidemia, hypertension, insulin
resistance, systemic inflammation, glucose intolerance and
oxidative stress.
Studies have shown that fruits, vegetables and beverages with
carotenoids, isoflavones, phytosterols and phytoestrogens
delay the onset of atherosclerosis or act as a chemoprotective
agent by interacting with underlying pathomechanisms.
Phytochemicals either exert their health benefits by reducing
the circulating levels of cholesterol or by limiting lipid
oxidation while others exhibit antiplatelet and anti-
inflammatory activities. They also neonatal thickening by
inhibiting proliferation of smooth muscles (Upadhyay, 2015).
Other phytochemicals such as Ferulic acidwhich is commonly
found in fruits and vegetables such as tomatoes and rice corn.
It decreases the level of inflammatory mediators (TNF-α,
prostaglandin E2) (Corbi et al., 2016).
Conclusion
Poor dietary practices has contributed a big percentage in the
development of chronic diseases including diabetes,
hypertension, cancer, and cardiovascular diseases. Various
aldehyde produced in the oxidation of PUFAs (Poly
unsaturated fatty acids) and sugars are known to initiate
several diseases including, diabetes, asthma, inflammation,
endothelial dysfunction and atherosclerosis (Lawrence, 2013).
Nutritionists, therefore, have a task of educating the
communities on the health benefits of phytochemicals.
Community members also need to know the foods rich in these
phytochemicals and the preparation methods for enhance the
bioavailability of different phytochemicals. Policies should
emphasize on the different food regulations to the
manufacturers to minimize malpractices of indicating
availability of certain nutrients in products of which the
nutrients mentioned are not presences.
List of abbreviations
DNA: Deoxyribonucleic acid
EGCg: Epigallocatechin-3-galate
HDL: High Density Lipoprotein
IGF: Insulin growth factor
PUFA: Poly Unsaturated Fatty Acids
RSS: Reactive sulfur species
TNF: Tumor Necrosis factor
Acknowledgment: The authors expresses a lot of gratitude to
researchers around them who have contributed a lot towards
the achievement of writing the articles. Gratitude also goes to
the institutions where the authors come from for having given
them the encouragement to do research review as a way of
achieving their carrier goals.
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Borlinghaus, J., Albrecht, F., Gruhlke, M. C. H., Nwachukwu,
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Table 1. Examples of Phytochemicals, food sources and their role in health
S/N Phytochemical Sources Health benefit Author
1. Quercetin

Induces apoptosis of prostate cancer cells
 Exhibit antioxidant activities
(Murakami, 2013)
2. Curcumin Turmeric

Enhance wound healing by activating the anti-inflammatory and
reactive oxygen species
(Sharad, 2013)
3. Sulforaphane Cruciferous vegetables

Interfere with early cancer development and progression (Yin et al., 2016)
4. Resveratrol Pines, berries and nuts

Inhibit lipid peroxidation, thrombocyte aggregation, thus playing
anti-oxidation, anti-inflammatory and vasodilation roles
(Yin et al., 2016)
Food sources of quercetin are; apples, peppers, tomatoes, black and blue berries, citrus fruits, spinach, kale and cruciferous vegetables
62542 International Journal of Current Research, Vol. 9, Issue, 12, pp.62540-62543, December, 2017

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62543 Monicah Njambi Kibe et al. The role of phytochemicals in prevention and control of chronic diseases