Hydroxytyrosol
Encyclopedia
Hydroxytyrosol is a phytochemical
with antioxidant
properties. After gallic acid
, hydroxytyrosol is believed to be one of the most powerful antioxidants. Its oxygen radical absorbance capacity
is 40,000 umolTE/g, which is ten times higher than that of green tea
, and two times higher than that of CoQ10.
In nature, hydroxytyrosol is found in olive leaf
which is used for medical purposes, with immunostimulant and antibiotic
properties. It also exists in olive oil
, in the form of its elenolic acid
ester
oleuropein
and, especially after degradation, in its plain form. Oleuropein
, along with oleocanthal
, are responsible for the bitter taste of extra virgin olive oil. Hydroxytyrosol itself in pure form is a colorless, odourless liquid. The olives, leaves and olive pulp contain large amounts of hydroxytyrosol (compared to olive oil
), most of which can be recovered to produce hydroxytyrosol extracts.
Studies have shown that a low dose of hydroxytyrosol reduces the consequences of sidestream smoke-induced oxidative stress
in rats.
Hydroxytyrosol has been demonstrated to be a monoamine oxidase inhibitor
(MAOI). It functions as a potent inhibitor of monoamine oxidase B
.
In the brain, it degrades to Homovanillyl alcohol
, via COMT.
Hydroxytyrosol is also metabolite
of the neurotransmitter
dopamine
.
Ex vivo data provide the first evidence of neuroprotective effects of oral hydroxytyrosol intake. Both, ex vivo and in vitro studies identified mitochondria as one target for hydroxytyrosol's preventive effects in the brain.
Phytochemical
Phytochemicals are biologically active chemical compounds that occur naturally in plants . Phytochemicals are the molecules responsible for the color and organoleptic properties . For example, the deep purple color of blueberries and the smell of garlic...
with antioxidant
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...
properties. After gallic acid
Gallic 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...
, hydroxytyrosol is believed to be one of the most powerful antioxidants. Its oxygen radical absorbance capacity
Oxygen radical absorbance capacity
Oxygen Radical Absorbance Capacity is a method of measuring antioxidant capacities in biological samples in vitro.A wide variety of foods has been tested using this method, with certain spices, berries and legumes rated highly. There exists no physiological proof in vivo that free-radical theory...
is 40,000 umolTE/g, which is ten times higher than that of 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...
, and two times higher than that of CoQ10.
In nature, hydroxytyrosol is found in olive leaf
Olive leaf
Olive leaf is the leaf of the olive tree . While olive oil is well known for its flavor and health benefits, the leaf has been used medicinally in various times and places. Natural olive leaf and olive leaf extracts , are now marketed as an anti-aging, immunostimulator and an antibiotic...
which is used for medical purposes, with immunostimulant and antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
properties. It also exists in olive oil
Olive oil
Olive oil is an oil obtained from the olive , a traditional tree crop of the Mediterranean Basin. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps...
, in the form of its elenolic acid
Elenolic acid
Elenolic acid is a component of olive oil and olive leaf extract. It can be considered as a marker for maturation of olives....
ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
oleuropein
Oleuropein
Oleuropein is a chemical compound found in olive leaf from the olive tree together with other closely related compounds such as 10-hydroxyoleuropein, ligstroside, and 10-hydroxyligstroside. All these compounds are tyrosol esters of elenolic acid that are further hydroxylated and glycosylated...
and, especially after degradation, in its plain form. Oleuropein
Oleuropein
Oleuropein is a chemical compound found in olive leaf from the olive tree together with other closely related compounds such as 10-hydroxyoleuropein, ligstroside, and 10-hydroxyligstroside. All these compounds are tyrosol esters of elenolic acid that are further hydroxylated and glycosylated...
, along with oleocanthal
Oleocanthal
Oleocanthal is a natural organic compound isolated from extra virgin olive oil. It is responsible for the slightly peppery "bite" of extra virgin olive oil. Oleocanthal is a tyrosol ester and its chemical structure is related to oleuropein that is also found in olive oil.Oleocanthal has been found...
, are responsible for the bitter taste of extra virgin olive oil. Hydroxytyrosol itself in pure form is a colorless, odourless liquid. The olives, leaves and olive pulp contain large amounts of hydroxytyrosol (compared to olive oil
Olive oil
Olive oil is an oil obtained from the olive , a traditional tree crop of the Mediterranean Basin. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps...
), most of which can be recovered to produce hydroxytyrosol extracts.
Studies have shown that a low dose of hydroxytyrosol reduces the consequences of sidestream smoke-induced oxidative stress
Oxidative stress
Oxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
in rats.
Hydroxytyrosol has been demonstrated to be a monoamine oxidase inhibitor
Monoamine oxidase inhibitor
Monoamine oxidase inhibitors are a class of antidepressant drugs prescribed for the treatment of depression. They are particularly effective in treating atypical depression....
(MAOI). It functions as a potent inhibitor of monoamine oxidase B
Monoamine oxidase B
Monoamine oxidase B, also known as MAOB, is a protein that in humans is encoded by the MAOB gene.The protein encoded by this gene belongs to the flavin monoamine oxidase family. It is an enzyme located in the mitochondrial outer membrane...
.
In the brain, it degrades to Homovanillyl alcohol
Homovanillyl alcohol
Homovanillyl alcohol is a metabolite of hydroxytyrosol, which in turn is a metabolite of the neurotransmitter dopamine....
, via COMT.
Hydroxytyrosol is also metabolite
Metabolite
Metabolites are the intermediates and products of metabolism. The term metabolite is usually restricted to small molecules. A primary metabolite is directly involved in normal growth, development, and reproduction. Alcohol is an example of a primary metabolite produced in large-scale by industrial...
of the neurotransmitter
Neurotransmitter
Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...
dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
.
Ex vivo data provide the first evidence of neuroprotective effects of oral hydroxytyrosol intake. Both, ex vivo and in vitro studies identified mitochondria as one target for hydroxytyrosol's preventive effects in the brain.