Theaflavin
Encyclopedia
Theaflavin and its derivatives, known collectively as theaflavins, are antioxidant
polyphenols that are formed from flavan-3-ol
s such as in tea
leaves during the enzymatic oxidation (called fermentation by the tea trade) of tea leaves, such as in black tea
. Theaflavins are types of thearubigin
s, and are therefore reddish in color. Analogous compounds include EGCG
in green tea
, theaflavins are not found in green tea. Despite huge implications regarding health benefits, as of 2008, little is known about the bioavailability
of these compounds in black tea, therefore it is not safe to assume that simply drinking black tea will bring out health benefits listed below as there is little known how well compounds are absorbed into the bloodstream. What is known is that EGCG
will metabolize into some theaflavins in the liver
.
moiety, can inhibit HIV-1 replication with multiple mechanisms of action
. Theaflavin derivatives have been found to have more potent anti-HIV-1 activity than catechin derivatives in laboratory investigations.
Epigallocatechin gallate
(EGCG), a catechin in green tea, binds to gp120
, which works in conjunction with gp41
, itself blocked by TF-3
(a theaflavin), both receptors of which HIV hijacks to enter into healthy human immune cells. Therefore, former and latter compounds have considerable potential to block HIV entry, though in real life situations other factors may complicate matters. More studies need to be done. See List section below.
Like EGCG, Theaflavins and Thearubigin
s compounds found in black teas penetrate the blood brain barrier, and have been shown to be effective against dementia in aging as well as AIDS related dementia
plaques in vitro.
levels in human trials, both total and LDL.
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...
polyphenols that are formed from flavan-3-ol
Flavan-3-ol
Flavan-3-ols are a class of flavonoids that use the 2-phenyl-3,4-dihydro-2H-chromen-3-ol skeleton. These compounds include the catechins and the catechin gallates....
s such as in tea
Tea
Tea is an aromatic beverage prepared by adding cured leaves of the Camellia sinensis plant to hot water. The term also refers to the plant itself. After water, tea is the most widely consumed beverage in the world...
leaves during the enzymatic oxidation (called fermentation by the tea trade) of tea leaves, such as in black tea
Black tea
Black tea is a variety of tea that is more oxidized than the oolong, green, and white varieties.All four varieties are made from leaves of the shrub Camellia sinensis. Black tea is generally stronger in flavor and contains more caffeine than the less oxidized teas. Two principal varieties of the...
. Theaflavins are types of thearubigin
Thearubigin
Thearubigins are polymeric polyphenols that are formed during the enzymatic oxidation of tea leaves. Thearubigins are red in colour. Therefore a black tea gives a reddish liquor while a green or white tea gives a much clearer one...
s, and are therefore reddish in color. Analogous compounds include EGCG
Epigallocatechin gallate
Epigallocatechin gallate , also known as epigallocatechin 3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin....
in green tea
Green tea
Green tea is made solely from the leaves of Camellia sinensis that have undergone minimal oxidation during processing. Green tea originates from China and has become associated with many cultures throughout Asia. It has recently become more widespread in the West, where black tea is traditionally...
, theaflavins are not found in green tea. Despite huge implications regarding health benefits, as of 2008, little is known about the bioavailability
Bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. By definition, when a medication is administered...
of these compounds in black tea, therefore it is not safe to assume that simply drinking black tea will bring out health benefits listed below as there is little known how well compounds are absorbed into the bloodstream. What is known is that EGCG
Epigallocatechin gallate
Epigallocatechin gallate , also known as epigallocatechin 3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin....
will metabolize into some theaflavins in the liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
.
HIV and dementia
Several tea polyphenols, especially those with galloylGallic acid
Gallic acid is a trihydroxybenzoic acid, a type of phenolic acid, a type of organic acid, also known as 3,4,5-trihydroxybenzoic acid, found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. The chemical formula is C6H23COOH. Gallic acid is found both free and as part of...
moiety, can inhibit HIV-1 replication with multiple mechanisms of action
Mechanism of action
In pharmacology, the term mechanism of action refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect...
. Theaflavin derivatives have been found to have more potent anti-HIV-1 activity than catechin derivatives in laboratory investigations.
Epigallocatechin gallate
Epigallocatechin gallate
Epigallocatechin gallate , also known as epigallocatechin 3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin....
(EGCG), a catechin in green tea, binds to gp120
Gp120
Envelope glycoprotein GP120 is a glycoprotein exposed on the surface of the HIV envelope. The 120 in its name comes from its molecular weight of 120 kilodaltons...
, which works in conjunction with gp41
Gp41
gp41 is a subunit of the envelope protein complex of retroviruses, including Human immunodeficiency virus and Simian-Human immunodeficiency virus. This glycoprotein subunit remains non-covalently-bound to gp120, and provides the second step by which HIV enters the cell...
, itself blocked by TF-3
Theaflavin digallate
Theaflavin digallate is an antioxidant polyphenol found in black tea, and a theaflavin derivative.-Health:* TF-3 is a potent scavenger of superoxide, even more so than EGCG....
(a theaflavin), both receptors of which HIV hijacks to enter into healthy human immune cells. Therefore, former and latter compounds have considerable potential to block HIV entry, though in real life situations other factors may complicate matters. More studies need to be done. See List section below.
Like EGCG, Theaflavins and Thearubigin
Thearubigin
Thearubigins are polymeric polyphenols that are formed during the enzymatic oxidation of tea leaves. Thearubigins are red in colour. Therefore a black tea gives a reddish liquor while a green or white tea gives a much clearer one...
s compounds found in black teas penetrate the blood brain barrier, and have been shown to be effective against dementia in aging as well as AIDS related dementia
AIDS dementia complex
AIDS dementia complex is a common neurological disorder associated with HIV infection and AIDS. It is a metabolic encephalopathy induced by HIV infection and fueled by immune activation of brain macrophages and microglia...
plaques in vitro.
Cholesterol
Theaflavins have also been found to reduce blood cholesterolCholesterol
Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...
levels in human trials, both total and LDL.
Cancer
Theaflavins act on numerous points regulating cancer cell growth, survival, and metastasis, including effects at the DNA, RNA, and protein levels.- Tea polyphenols including theaflavins are found to reduce angiogenesisAngiogenesisAngiogenesis is the physiological process involving the growth of new blood vessels from pre-existing vessels. Though there has been some debate over terminology, vasculogenesis is the term used for spontaneous blood-vessel formation, and intussusception is the term for the formation of new blood...
, which is implicated in non-liquid cancers, an area of intense current research, by decreasing vascular endothelial growth factorVascular endothelial growth factorVascular endothelial growth factor is a signal protein produced by cells that stimulates vasculogenesis and angiogenesis. It is part of the system that restores the oxygen supply to tissues when blood circulation is inadequate....
production and receptor phosphorylation. - Nitric oxideNitric oxideNitric oxide, also known as nitrogen monoxide, is a diatomic molecule with chemical formula NO. It is a free radical and is an important intermediate in the chemical industry...
production was reduced by EGCG and black tea theaflavins by suppressing inducible nitric oxide synthaseNitric oxide synthaseNitric oxide synthases are a family of enzymes that catalyze the production of nitric oxide from L-arginine. NO is an important cellular signaling molecule, having a vital role in many biological processes...
via blocking nuclear translocation of the NF-kappaB as a result of decreased IkappaB kinase activity. - MetastasisMetastasisMetastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...
is inhibited via effects on UrokinaseUrokinaseUrokinase , also called urokinase-type plasminogen activator , is a serine protease . Urokinase was originally isolated from human urine, but is present in several physiological locations, such as blood stream and the extracellular matrix...
and Matrix metalloproteinaseMatrix metalloproteinaseMatrix metalloproteinases are zinc-dependent endopeptidases; other family members are adamalysins, serralysins, and astacins. The MMPs belong to a larger family of proteases known as the metzincin superfamily....
s. - Three black tea theaflavins, namely theaflavin 3-O-gallate, theaflavin 3’-O-gallate, theaflavin 3,3’di-O-gallate and thearubigins as mimics the effects of insulin/IGF-1Insulin-like growth factor 1Insulin-like growth factor 1 also known as somatomedin C is a protein that in humans is encoded by the IGF1 gene. IGF-1 has also been referred to as a "sulfation factor" and its effects were termed "nonsuppressible insulin-like activity" in the 1970s.IGF-1 is a hormone similar in molecular...
action on mammalian FOXO1a, which is involved in longevity and aging. Furthermore, EGCG's effects on FOX01a are also due to its being converted to Thearubigins. - Theaflavin inhibited tumor necrosis factor-alpha mediated Interleukin-8 gene expression, as measured by luciferaseLuciferaseLuciferase is a generic term for the class of oxidative enzymes used in bioluminescence and is distinct from a photoprotein. One famous example is the firefly luciferase from the firefly Photinus pyralis. "Firefly luciferase" as a laboratory reagent usually refers to P...
assay and Northern blotNorthern blotThe northern blot is a technique used in molecular biology research to study gene expression by detection of RNA in a sample. With northern blotting it is possible to observe cellular control over structure and function by determining the particular gene expression levels during differentiation,...
analysis, at concentrations of 10 and 30 microg/mL. - TF-2Theaflavin-3-gallateTheaflavin-3-gallate is a theaflavin derivative. It can be found in black tea....
inhibits colon cancer linked gene COX-2, even more than EGCGEpigallocatechin gallateEpigallocatechin gallate , also known as epigallocatechin 3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin.... - TF-3 is a potent scavenger of superoxideSuperoxideA superoxide, also known by the obsolete name hyperoxide, is a compound that possesses the superoxide anion with the chemical formula O2−. The systematic name of the anion is dioxide. It is important as the product of the one-electron reduction of dioxygen O2, which occurs widely in nature...
, even more so than EGCGEpigallocatechin gallateEpigallocatechin gallate , also known as epigallocatechin 3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin....
.
Oxidation
Oxidation of theaflavins produce many products, including bistheaflavin-A and bistheaflavin-B.List of Theaflavins with health benefits
- Theaflavin-3'-monogallate (TFMG, TF-2) causes apoptosisApoptosisApoptosis 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...
in colon cancer cells. - Theaflavin-3,3'-digallate (TFDG, TF3) binds to gp41Gp41gp41 is a subunit of the envelope protein complex of retroviruses, including Human immunodeficiency virus and Simian-Human immunodeficiency virus. This glycoprotein subunit remains non-covalently-bound to gp120, and provides the second step by which HIV enters the cell...
of HIVHIVHuman immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
as well as inhibit 3CLPro of severe acute respiratory syndromeSevere acute respiratory syndromeSevere Acute Respiratory Syndrome is a respiratory disease in humans which is caused by the SARS coronavirus . Between November 2002 and July 2003 an outbreak of SARS in Hong Kong nearly became a pandemic, with 8,422 cases and 916 deaths worldwide according to the WHO...
(SARS). - 3-Isotheaflavin-3-gallate (TF2B) inhibits 3CLPro of SARSSevere acute respiratory syndromeSevere Acute Respiratory Syndrome is a respiratory disease in humans which is caused by the SARS coronavirus . Between November 2002 and July 2003 an outbreak of SARS in Hong Kong nearly became a pandemic, with 8,422 cases and 916 deaths worldwide according to the WHO...
.