3-Indolepropionic acid (IPA), or indole-3-propionic acid, is a potent neuroprotective

antioxidant Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricants ...

, plant auxin, and

natural product A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical sy ...

in humans that is being studied for therapeutic use in Alzheimer's disease. It is endogenously produced by

human microbiota This article lists some of the species recognized as belonging to the human microbiome. Whole-body distributed *'' Acinetobacter calcoaceticus'' *''Burkholderia cepacia'' *'' Pseudomonas pseudoalcaligenes'' *''Peptostreptococcus spp'' Natu ...

and has only been detected ''

in vivo Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...

'' when the species '' Clostridium sporogenes'' is present in the gastrointestinal tract. , ''C. sporogenes'', which uses

tryptophan Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromati ...

to synthesize IPA, is the only species of bacteria known to synthesize IPA ''in vivo'' at levels which are subsequently detectable in the

blood plasma Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the ...

of the host. IPA is an even more potent scavenger of

hydroxyl radical The hydroxyl radical is the diatomic molecule . The hydroxyl radical is very stable as a dilute gas, but it decays very rapidly in the condensed phase. It is pervasive in some situations. Most notably the hydroxyl radicals are produced from the ...

s than

melatonin Melatonin is a natural product found in plants and animals. It is primarily known in animals as a hormone released by the pineal gland in the brain at night, and has long been associated with control of the sleep–wake cycle. In vertebrat ...

, the most potent scavenger of hydroxyl radicals that is synthesized by human enzymes. Similar to melatonin but unlike other antioxidants, it scavenges radicals without subsequently generating reactive and pro-oxidant intermediate compounds. In 2017, elevated concentrations of IPA in human

were found to be correlated with a lower risk of

type 2 diabetes Type 2 diabetes, formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urinati ...

and higher consumption of

fiber Fiber or fibre (from la, fibra, links=no) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorpora ...

-rich foods.

Biosynthesis in humans and cellular effects

Metabolism

IPA can be converted in the

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...

kidneys The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; bloo ...

to 3-indoleacrylic acid, which is subsequently conjugated with glycine, forming indolylacryloyl glycine.

History

The neuroprotective, antioxidant, and anti-amyloid properties of IPA were first reported by a group of investigators in July 1999, led by Dr. Pappolla and Dr. Poeggeler at the University of South Alabama.

References

{{DEFAULTSORT:Indolepropionic acid, 3- Antioxidants Indoles Propionic acids Auxins Biomolecules

Biosynthesis in humans and cellular effects

Metabolism

History

See also

References