Oleuropein is a chemical compound 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...

 from the olive

Olive

The olive , Olea europaea), is a species of a small tree in the family Oleaceae, native to the coastal areas of the eastern Mediterranean Basin as well as northern Iran at the south end of the Caspian Sea.Its fruit, also called the olive, is of major agricultural importance in the...

 tree (and leaves of privet) together with other closely related compounds such as 10-hydroxyoleuropein, ligstroside, and 10-hydroxyligstroside. All these compounds are tyrosol

Tyrosol

Tyrosol is a natural phenolic antioxidant present in a variety of natural sources. The principal source in the human diet is olive oil. Tyrosol is a derivative of phenethyl alcoholAs an antioxidant, tyrosol can protect cells against injury due to oxidation...

 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...

s of 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....

 that are further hydroxylated

Hydroxylation

Hydroxylation is a chemical process that introduces a hydroxyl group into an organic compound. In biochemistry, hydroxylation reactions are often facilitated by enzymes called hydroxylases. Hydroxylation is the first step in the oxidative degradation of organic compounds in air...

 and glycosylated

Glycosylation

Glycosylation is the reaction in which a carbohydrate, i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule . In biology glycosylation refers to the enzymatic process that attaches glycans to proteins, lipids, or other organic molecules...

. Oleuropein and its 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...

 hydroxytyrosol

Hydroxytyrosol

Hydroxytyrosol is a phytochemical with antioxidant properties. After gallic acid, hydroxytyrosol is believed to be one of the most powerful antioxidants...

 have powerful 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...

 activity both in vivo

In vivo

In vivo is experimentation using a whole, living organism as opposed to a partial or dead organism, or an in vitro controlled environment. Animal testing and clinical trials are two forms of in vivo research...

and in vitro

In vitro

In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...

and give extra-virgin 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...

 its bitter, pungent taste

Taste

Taste is one of the traditional five senses. It refers to the ability to detect the flavor of substances such as food, certain minerals, and poisons, etc....

. Oleuropein preparations have been claimed for several pharmacological effects among them strengthening of the immune system

Immune system

An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...

. A study in rats suggests oleuropein enhances thermogenesis

Thermogenesis

Thermogenesis is the process of heat production in organisms. It occurs mostly in warm-blooded animals, but a few species of thermogenic plants exist.-Types:...

 by increasing the thermogenin

Thermogenin

Thermogenin is an uncoupling protein found in the mitochondria of brown adipose tissue . It is used to generate heat by non-shivering thermogenesis...

 content in brown adipose tissue

Brown adipose tissue

Brown adipose tissue or brown fat is one of two types of fat or adipose tissue found in mammals....

 and the secretion of noradrenaline and adrenaline.