Health effects of polyphenols
Encyclopedia
Although phenol
and its vapors are corrosive to the eyes, skin and respiratory tract, and hydroquinone
is also toxic, most other polyphenol
s do not share the same toxicity
and are considered safe for consumption, having long been associated with herbalism
. For instance, in the Indian subcontinent
's ancient Ayurveda
system of medicine, the pomegranate
has extensively been used as a source of traditional remedies
for thousands of years.
The subject of the relationship between polyphenols content and health is still controversial
as claims are difficult to prove scientifically.
The possible health benefits of specific polyphenols remain unproved. Polyphenols have also been investigated in organic produce as a source of additional health benefit, but no conclusion is possible from existing research.
, antiviral
, antimutagenic, anticarcinogenic, antiproliferative and vasodilatory actions. Polyphenols may have antibacterial activity useful to combat tooth decay caused by Streptococcus mutans
. Polyphenols are listed as nootropic
s purported to improve mental functions such as cognition, memory, intelligence, motivation, attention and concentration.
Phenolic-rich extracts from edible marine algae may have an anti-proliferative effect on colon cancer cells and an anti-diabetic effect by means of interactions of phlorotannin
s with α-amylase and α-glucosidase in the gut. Molecular mechanisms possibly underlying activities of anti-inflammatory polyphenols would be down-regulation of COX-2 and iNOS through suppression of NF-κB activation.
increased by polyphenols was demonstrated in Caenorhabditis elegans
. This longevity increase may be due to a caloric restriction effect.
Grape seed polyphenolic extract may improve the phenotype in a Drosophila model of tauopathy
.
Polyphenol-enriched extract can attenuate food allergy
symptoms in sensitized mice.
and doxorubicin
. When tested some polyphenols induced DNA
mutation
s in MLL gene
, which are common findings in neonatal acute leukemia
. Polyphenols have both anticarcinogenic - proapoptotic
effect and a carcinogenic, DNA damaging, mutagen
ic potential. Adults seem to rapidly metabolize most of polyphenols, so toxic, mutagen
ic effect may not be pronounced in regular low doses intaken with food. However human embryos detoxification system is not mature enough to deal with polyphenols, which have possibility to cross the placenta barier.
(e.g. from plant sources) in vitro in model systems, possibly reducing its absorption especially in vegetarian nutrition
.
Phenol
Phenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...
and its vapors are corrosive to the eyes, skin and respiratory tract, and hydroquinone
Hydroquinone
Hydroquinone, also benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, having the chemical formula C6H42. Its chemical structure, shown in the table at right, has two hydroxyl groups bonded to a benzene ring in a para position. It is a white granular solid...
is also toxic, most other polyphenol
Polyphenol
Polyphenols are a structural class of natural, synthetic, and semisynthetic organic chemicals characterized by the presence of large multiples of phenol structural units...
s do not share the same toxicity
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...
and are considered safe for consumption, having long been associated with herbalism
Herbalism
Herbalism is a traditional medicinal or folk medicine practice based on the use of plants and plant extracts. Herbalism is also known as botanical medicine, medical herbalism, herbal medicine, herbology, herblore, and phytotherapy...
. For instance, in the Indian subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
's ancient Ayurveda
Ayurveda
Ayurveda or ayurvedic medicine is a system of traditional medicine native to India and a form of alternative medicine. In Sanskrit, words , meaning "longevity", and , meaning "knowledge" or "science". The earliest literature on Indian medical practice appeared during the Vedic period in India,...
system of medicine, the pomegranate
Pomegranate
The pomegranate , Punica granatum, is a fruit-bearing deciduous shrub or small tree growing between five and eight meters tall.Native to the area of modern day Iran, the pomegranate has been cultivated in the Caucasus since ancient times. From there it spread to Asian areas such as the Caucasus as...
has extensively been used as a source of traditional remedies
Cure
A cure is a completely effective treatment for a disease.The Cure is an English rock band.Cure, or similar, may also refer to:-Film and television:* The Cure , a short film starring Charlie Chaplin...
for thousands of years.
The subject of the relationship between polyphenols content and health is still controversial
Controversy
Controversy is a state of prolonged public dispute or debate, usually concerning a matter of opinion. The word was coined from the Latin controversia, as a composite of controversus – "turned in an opposite direction," from contra – "against" – and vertere – to turn, or versus , hence, "to turn...
as claims are difficult to prove scientifically.
The possible health benefits of specific polyphenols remain unproved. Polyphenols have also been investigated in organic produce as a source of additional health benefit, but no conclusion is possible from existing research.
In vitro effects
Mainly from in vitro studies, polyphenols have been reported to have antimicrobialAntimicrobial
An anti-microbial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Antimicrobial drugs either kill microbes or prevent the growth of microbes...
, antiviral
Antiviral drug
Antiviral drugs are a class of medication used specifically for treating viral infections. Like antibiotics for bacteria, specific antivirals are used for specific viruses...
, antimutagenic, anticarcinogenic, antiproliferative and vasodilatory actions. Polyphenols may have antibacterial activity useful to combat tooth decay caused by Streptococcus mutans
Streptococcus mutans
Streptococcus mutans is a facultatively aerobic, Gram-positive coccus-shaped bacterium commonly found in the human oral cavity and is a significant contributor to tooth decay.The microbe was first described by J Kilian Clarke in 1924.-Introduction:...
. Polyphenols are listed as nootropic
Nootropic
Nootropics , also referred to as smart drugs, brain steroids, memory enhancers, cognitive enhancers, and intelligence enhancers, are drugs, supplements, nutraceuticals, and functional foods that improve mental functions such as cognition, memory, intelligence, motivation, attention, and concentration...
s purported to improve mental functions such as cognition, memory, intelligence, motivation, attention and concentration.
Phenolic-rich extracts from edible marine algae may have an anti-proliferative effect on colon cancer cells and an anti-diabetic effect by means of interactions of phlorotannin
Phlorotannin
A phlorotannin is a type of tannin found in brown algae such as kelps and rockweeds or sargassacean species. Contrary to hydrolysable or condensed tannins, these compounds are oligomers of phloroglucinol...
s with α-amylase and α-glucosidase in the gut. Molecular mechanisms possibly underlying activities of anti-inflammatory polyphenols would be down-regulation of COX-2 and iNOS through suppression of NF-κB activation.
Research with biological model species
LongevityLongevity
The word "longevity" is sometimes used as a synonym for "life expectancy" in demography or known as "long life", especially when it concerns someone or something lasting longer than expected ....
increased by polyphenols was demonstrated in Caenorhabditis elegans
Caenorhabditis elegans
Caenorhabditis elegans is a free-living, transparent nematode , about 1 mm in length, which lives in temperate soil environments. Research into the molecular and developmental biology of C. elegans was begun in 1974 by Sydney Brenner and it has since been used extensively as a model...
. This longevity increase may be due to a caloric restriction effect.
Grape seed polyphenolic extract may improve the phenotype in a Drosophila model of tauopathy
Tauopathy
Tauopathies are a class of neurodegenerative diseases associated with the pathological aggregation of tau protein in the human brain.The best known of these illnesses is Alzheimer's disease , where tau protein is deposited within neurons in the form of neurofibrillary tangles...
.
Polyphenol-enriched extract can attenuate food allergy
Food allergy
A food allergy is an adverse immune response to a food protein. They are distinct from other adverse responses to food, such as food intolerance, pharmacological reactions, and toxin-mediated reactions....
symptoms in sensitized mice.
Carcinogenesis
Many natural polyphenols share the properity with some chemotherapeutic anticancer drugs such etoposideEtoposide
Etoposide phosphate is an anti-cancer agent. It is known in the laboratory as a topoisomerase poison. Etoposide is often incorrectly referred to as a topoisomerase inhibitor in order to avoid using the term "poison" in a clinical setting...
and doxorubicin
Doxorubicin
Doxorubicin INN is a drug used in cancer chemotherapy. It is an anthracycline antibiotic, closely related to the natural product daunomycin, and like all anthracyclines, it works by intercalating DNA....
. When tested some polyphenols induced DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
s in MLL gene
MLL (gene)
Histone-lysine N-methyltransferase HRX is an enzyme that in humans is encoded by the MLL gene.MLL is a histone methyltransferase deemed a positive global regulator of gene transcription...
, which are common findings in neonatal acute leukemia
Acute leukemia
Acute leukemia or acute leukaemia is a generic term used to describe a family of serious medical conditions relating to an original diagnosis of leukemia...
. Polyphenols have both anticarcinogenic - proapoptotic
Apoptosis
Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...
effect and a carcinogenic, DNA damaging, mutagen
Mutagen
In genetics, a mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level. As many mutations cause cancer, mutagens are therefore also likely to be carcinogens...
ic potential. Adults seem to rapidly metabolize most of polyphenols, so toxic, mutagen
Mutagen
In genetics, a mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level. As many mutations cause cancer, mutagens are therefore also likely to be carcinogens...
ic effect may not be pronounced in regular low doses intaken with food. However human embryos detoxification system is not mature enough to deal with polyphenols, which have possibility to cross the placenta barier.
Others adverse effects
Polyphenols bind with nonheme ironHuman iron metabolism
Human iron metabolism is the set of chemical reactions maintaining human homeostasis of iron. Iron is an essential element for most life on Earth, including human beings. The control of this necessary but potentially toxic substance is an important part of many aspects of human health and disease...
(e.g. from plant sources) in vitro in model systems, possibly reducing its absorption especially in vegetarian nutrition
Vegetarian nutrition
Vegetarian nutrition is the set of health-related challenges and advantages of vegetarian diets.Well-planned vegetarian and vegan diets are nutritionally adequate and are appropriate for all stages of the life cycle, including during pregnancy, lactation, infancy, childhood, and adolescence...
.
Further reading
Books- Fraga, Cesar G. (editor) Plant Phenolics and Human Health: Biochemistry, Nutrition and Pharmacology. 2010. Wiley. ISBN 9780470287217
External links
- Book Review of "Plant Phenolics and Human Health", Edited by Cesar G. Fraga (by Manfred Kroger, 2010)