Naringin is a flavanone glycoside. It is a major flavonoid in grapefruit

Grapefruit

The grapefruit , is a subtropical citrus tree known for its sour fruit, an 18th-century hybrid first bred in Barbados. When found, it was named the "forbidden fruit"; it has also been misidentified with the pomelo or shaddock , one of the parents of this hybrid, the other being sweet orange The...

 and gives the grapefruit juice

Grapefruit juice

Grapefruit juice is the fruit juice from grapefruits. It is rich in Vitamin C and ranges from sweet-tart to very sour. It is considered by some cultures to be a mystical tonic which promotes health and vigor. Certain civilizations have had holy men who live on Grapefruit juice alone...

 its bitter taste. It is metabolized to the flavanone

Flavanone

The flavanones are a type of flavonoids. They are generally glycosylated by a disaccharide at position seven to give flavanone glycosides.-List of flavanones:* Butin* Eriodictyol* Hesperetin* Hesperidin* Homoeriodictyol* Isosakuranetin* Naringenin...

 naringenin

Naringenin

Naringenin is a flavanone, a type of flavonoid, that is considered to have a bioactive effect on human health as antioxidant, free radical scavenger, anti-inflammatory, carbohydrate metabolism promoter, and immune system modulator. It is the predominant flavanone in grapefruit.-Biological...

 in humans. Both naringenin

Naringenin

Naringenin is a flavanone, a type of flavonoid, that is considered to have a bioactive effect on human health as antioxidant, free radical scavenger, anti-inflammatory, carbohydrate metabolism promoter, and immune system modulator. It is the predominant flavanone in grapefruit.-Biological...

 and hesperetin

Hesperetin

Hesperetin is a bioflavonoid and, to be more specific, a flavanone. Hesperidin is water-soluble due to the presence of the sugar part in its structure, so on ingestion it releases its aglycone, i.e, hesperetin....

, which are the aglycone

Aglycone

An aglycone is the non-sugar compound remaining after replacement of the glycosyl group from a glycoside by a hydrogen atom. The spelling aglycon is sometimes encountered .Classes of phytochemicals found in the aglycone and glycosides forms :...

s of naringin and hesperidin

Hesperidin

Hesperidin is a flavanone glycoside found abundantly in citrus fruits. Its aglycone form is called hesperetin. Its name is derived from the Hesperides nymphs of Greek mythology. Hesperidin is believed to play a role in plant defense. It acts as an antioxidant according to in vitro studies...

, occur naturally in citrus fruits.

Activity

Naringin exerts a variety of pharmacological effects such as 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, blood lipid

Lipid

Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...

 lowering, anticancer activity, and inhibition

Enzyme inhibitor

An enzyme inhibitor is a molecule that binds to enzymes and decreases their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. They are also used as herbicides and pesticides...

 of selected drug-metabolizing cytochrome P450 enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s, including CYP3A4

CYP3A4

Cytochrome P450 3A4 , a member of the cytochrome P450 mixed-function oxidase system, is one of the most important enzymes involved in the metabolism of xenobiotics in the body. CYP3A4 is involved in the oxidation of the largest range of substrates of all the CYPs. As a result, CYP3A4 is present in...

 and CYP1A2

CYP1A2

Cytochrome P450 1A2 , a member of the cytochrome P450 mixed-function oxidase system, is involved in the metabolism of xenobiotics in the body...

, which may result in drug-drug interactions in vivo. Ingestion of naringin and related flavonoids can also affect the intestinal absorption of certain drugs, leading to either an increase or decrease in circulating drug levels. To avoid interference with drug absorption and metabolism, the consumption of citrus (esp. grapefruit) and other juices with medications is contraindicated.
Naringin, followed by rutin

Rutin

Rutin, also called rutoside, quercetin-3-O-rutinoside and sophorin, is a citrus flavonoid glycoside found in buckwheat, the leaves and petioles of Rheum species, and asparagus...

, was the most potent flavonoid inhibitor of VEGF

Vascular endothelial growth factor

Vascular 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....

 release, which causes angiogenesis

Angiogenesis

Angiogenesis 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...

, out of 21 flavonoids.

Naringin may have protective effects on cognition and oxidative damage.

Use

When naringin is treated with potassium hydroxide

Potassium hydroxide

Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...

 or another strong base, and then catalytically hydrogenated

Hydrogenation

Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...

, it becomes a naringin dihydrochalcone

Naringin dihydrochalcone

Naringin dihydrochalcone, sometimes abbreviated to naringin DC, is an artificial sweetener derived from naringin, a bitter compound found in citrus....

, a compound roughly 300-1800 times sweeter than sugar at threshold concentrations.