Inositol
Encyclopedia
Inositol or cyclohexane-1,2,3,4,5,6-hexol is a chemical compound
with formula 6126 or (-CHOH-)6, a sixfold alcohol
(polyol
) of cyclohexane
. It exists in nine possible stereoisomers, of which the most prominent form, widely occurring in nature, is cis-1,2,3,5-trans-4,6-cyclohexanehexol, or myo-inositol (former name meso-inositol). Inositol is a carbohydrate, though not a classical sugar
. It is almost tasteless, with a small amount of sweetness.
Myo-inositol plays an important role as the structural basis for a number of secondary messengers in eukaryotic
cell
s, including inositol phosphate
s, phosphatidylinositol
(PI) and phosphatidylinositol phosphate
(PIP) lipids. Inositol or its phosphates and associated lipids are found in many foods, in particular fruit, especially cantaloupe
and orange
s. In plants, the hexaphosphate of inositol, phytic acid
or its salts, the phytates, are found. Phytic acid occurs also in cereal
s with high bran
content and also nuts and beans, but inositol as phytate is not directly bioavailable to humans in the diet, since it is not digestible (some food preparation techniques partly break down phytates to change this—see phytic acid
for details). Inositol as it occurs in certain plant-derived substances such as lecithin
s, however, is well-absorbed and relatively bioavailable.
Myo-inositol was once considered as a member of the vitamin B complex, however, because it is produced by the human body from glucose
, it is not an essential nutrient
. Some substances such as niacin
can also be synthesized in the body, but are not made in amounts considered adequate for good health, and thus are still classified as essential nutrients. However, there is no convincing evidence that this is the case for myo-inositol.
that possesses an optically inactive plane of symmetry through the molecule, and meso-inositol is an obsolete name that refers to myo-inositol. Besides myo-inositol, the other naturally occurring stereoisomers (though in minimal quantities) are scyllo
-, muco
-, D-chiro
-, and neo-inositol
. The other possible isomers are L-chiro
-, allo
-, epi
-, and cis-inositol
. As their name denotes, the two chiro inositols are the only pair of inositol enantiomers, but they are enantiomers of each other, not of myo-inositol.
In its most stable conformational geometry, the myo-inositol isomer assumes the chair conformation
, which puts the maximum number of hydroxyls to the equatorial position, where they are farthest apart from each other. In this conformation the natural myo isomer has a structure in which five of the six hydroxyl
s (the 1st, 3rd, 4th, 5th, and 6th are equatorial
, whereas the 2nd hydroxyl group is axial
.
(G-6-P) in two steps. First, G-6-P is isomer
ised by an inositol-3-phosphate synthase
enzyme (called ISYNA1) to myo-inositol 1-phosphate, which is then dephosphorylated by an Inositol monophosphatase
enzyme (called IMPase 1) to give free myo-inositol. In humans most inositol is synthesized in the kidneys, in typical amounts of a few grams per day.
, which is inositol hexakisphosphate (IP6), also known as phytate when in salt
form, is the principal storage form of phosphorus
in many plant
tissue
s, especially bran
and seed
s. Neither the inositol nor the phosphate in phytic acid in plants is available to humans, or to animals who are not ruminants, since it cannot be broken down, except by bacteria. Moreover, phytic acid also chelates important minerals such as calcium
, magnesium
, iron
, and zinc
, making them unabsorbable, and contributing to mineral deficiencies in people whose diets rely high bran and seed diets for their mineral intake, such as occurs in developing countries.
Inositol penta- (IP5), tetra- (IP4), and triphosphate (IP3) are also called "phytates."
, professor Edward Bartow of the University of Iowa
presented a commercially viable means of extracting large amounts of inositol from waste corn. As a possible use for the chemical, he suggested inositol nitrate as a more stable alternative to nitroglycerin. Today, inositol nitrate is used to gelatinize nitrocellulose
, and thus can be found in many modern explosives and solid rocket propellants.
, obsessive-compulsive disorder
, agoraphobia
, and unipolar
and bipolar depression.
In a single double-blind
study on 13 patients, Myo-inositol (18 grams daily) has been found to reduce the symptoms of obsessive-compulsive disorder
(OCD) significantly, with effectiveness equal to SSRIs and virtually without side-effects. In a double-blind, controlled trial, myo-inositol (18 grams daily) was superior to fluvoxamine
for decreasing the number of panic attacks and other side-effect
s.
Patients suffering from clinical depression
, in general, have decreased levels of inositol in their cerebrospinal fluid
. A double-blind, placebo
-controlled study of depressed patients showed that a high dose of inositol (12 grams daily) resulted in significant improvement of symptoms, with no changes noted in liver
, kidney
, or hematological
function. A meta-analysis of randomized trials of inositol for depression was not able to determine if inositol is of benefit.
Older research suggests that lithium functions primarily by decreasing myo-inositol concentrations in bipolar patients; however the conclusions of this research are unsupported and have been questioned. Other studies suggest that lithium treatment may further inhibit the enzyme inositol monophosphatase
, leading to higher intracellular levels of inositol triphosphate
, an effect that was enhanced further by administration of an inositol triphosphate reuptake inhibitor
.
(DCI) has been found in two double-blind studies to be an effective treatment for many of the clinical hallmarks of polycystic ovary syndrome
(PCOS), including insulin resistance
, hyperandrogenism
, and oligo-amenorrhea; the impetuses for these studies were the observed defects in DCI metabolism in PCOS and the implication of DCI in insulin signal transduction. Another small, placebo-controlled study has demonstrated that myo-inositol supplementation improves features of dysmetabolic syndrome in post-menopausal women, including triglycerides, HDL cholesterol, and diastolic blood pressure
.
Animal studies suggest inositol reduces the severity of the osmotic demyelination syndrome if given prior to rapid correction of chronic hyponatraemia. Further study is required prior to its application in humans for this indication.
Studies from in vitro
experiments, animal studies, and limited clinical experiences, claim that inositol may be used effectively against some types of cancer, in particular, when used in combination with phytic acid
.
(or cutting agent) in many illegal drugs, such as cocaine
, methamphetamine
, and sometimes heroin. It is presumed that this use is connected with the substance's solubility and near-lack of taste.
form, and the non-available phytate form in grains. According to research, foods containing the highest concentrations of myo-inositol (including its compounds) include fruits, beans, grains and nuts. Beans and grains, however, as seeds contain large amounts of inositol as phytate.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with formula 6126 or (-CHOH-)6, a sixfold alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
(polyol
Polyol
A polyol is an alcohol containing multiple hydroxyl groups. In two technological disciplines the term "polyol" has a special meaning: food science and polymer chemistry.- Polyols in food science :...
) of cyclohexane
Cyclohexane
Cyclohexane is a cycloalkane with the molecular formula C6H12. Cyclohexane is used as a nonpolar solvent for the chemical industry, and also as a raw material for the industrial production of adipic acid and caprolactam, both of which being intermediates used in the production of nylon...
. It exists in nine possible stereoisomers, of which the most prominent form, widely occurring in nature, is cis-1,2,3,5-trans-4,6-cyclohexanehexol, or myo-inositol (former name meso-inositol). Inositol is a carbohydrate, though not a classical sugar
Sugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...
. It is almost tasteless, with a small amount of sweetness.
Myo-inositol plays an important role as the structural basis for a number of secondary messengers in eukaryotic
Eukaryote
A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...
cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
s, including inositol phosphate
Inositol phosphate
Inositol phosphates are a group of mono- to polyphosphorylated inositols. They play crucial roles in diverse cellular functions, such as cell growth, apoptosis, cell migration, endocytosis, and cell differentiation.The group comprises:...
s, phosphatidylinositol
Phosphatidylinositol
Phosphatidylinositol is a negatively charged phospholipid and a minor component in the cytosolic side of eukaryotic cell membranes....
(PI) and phosphatidylinositol phosphate
Phosphatidylinositol phosphate
Phosphatidylinositol phosphate may refer to:* Phosphatidylinositol 3-phosphate, also known as PIP* Phosphatidylinositol 4-phosphate, also known as PIP* Phosphatidylinositol 5-phosphate, also known as PIP...
(PIP) lipids. Inositol or its phosphates and associated lipids are found in many foods, in particular fruit, especially cantaloupe
Cantaloupe
"Rockmelon" redirects here, for the band see Rockmelons. See also Cantaloupe .Cantaloupe refers to a variety of Cucumis melo, a species in the family Cucurbitaceae which includes nearly all melons and squashes. Cantaloupes range in size from...
and orange
Orange (fruit)
An orange—specifically, the sweet orange—is the citrus Citrus × sinensis and its fruit. It is the most commonly grown tree fruit in the world....
s. In plants, the hexaphosphate of inositol, phytic acid
Phytic acid
Phytic acid is the principal storage form of phosphorus in many plant tissues, especially bran and seeds. Phytate is not digestible to humans or nonruminant animals, however, so it is not a source of either inositol or phosphate if eaten directly...
or its salts, the phytates, are found. Phytic acid occurs also in cereal
Cereal
Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...
s with high bran
Bran
Bran is the hard outer layer of grain and consists of combined aleurone and pericarp. Along with germ, it is an integral part of whole grains, and is often produced as a by-product of milling in the production of refined grains. When bran is removed from grains, the grains lose a portion of their...
content and also nuts and beans, but inositol as phytate is not directly bioavailable to humans in the diet, since it is not digestible (some food preparation techniques partly break down phytates to change this—see phytic acid
Phytic acid
Phytic acid is the principal storage form of phosphorus in many plant tissues, especially bran and seeds. Phytate is not digestible to humans or nonruminant animals, however, so it is not a source of either inositol or phosphate if eaten directly...
for details). Inositol as it occurs in certain plant-derived substances such as lecithin
Lecithin
Lecithin is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues, and in egg yolk, composed of phosphoric acid, choline, fatty acids, glycerol, glycolipids, triglycerides, and phospholipids .The word lecithin was originally coined in 1847 by...
s, however, is well-absorbed and relatively bioavailable.
Myo-inositol was once considered as a member of the vitamin B complex, however, because it is produced by the human body from glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
, it is not an essential nutrient
Essential nutrient
An essential nutrient is a nutrient required for normal body functioning that either cannot be synthesized by the body at all, or cannot be synthesized in amounts adequate for good health , and thus must be obtained from a dietary source...
. Some substances such as niacin
Niacin
"Niacin" redirects here. For the neo-fusion band, see Niacin .Niacin is an organic compound with the formula and, depending on the definition used, one of the forty to eighty essential human nutrients.Niacin is one of five vitamins associated with a pandemic deficiency disease: niacin deficiency...
can also be synthesized in the body, but are not made in amounts considered adequate for good health, and thus are still classified as essential nutrients. However, there is no convincing evidence that this is the case for myo-inositol.
Isomers and structure
The isomer myo-inositol is a meso compoundMeso compound
A meso compound or meso isomer is a non-optically active member of a set of stereoisomers, at least two of which are optically active. This means that despite containing two or more stereocenters it is not chiral. A meso compound is superimposable on its mirror image, and it does not produce a ""...
that possesses an optically inactive plane of symmetry through the molecule, and meso-inositol is an obsolete name that refers to myo-inositol. Besides myo-inositol, the other naturally occurring stereoisomers (though in minimal quantities) are scyllo
Scyllo-inositol
scyllo-Inositol is one of the stereoisomers of inositol. It is also known as scyllitol, cocositol, quercinitol, and 1,3,5/2,4,6-hexahydroxycyclohexane...
-, muco
Muco-inositol
muco-Inositol is one of the stereoisomers of inositol.-See also:*allo-Inositol*cis-Inositol*D-chiro-Inositol*L-chiro-Inositol*epi-Inositol*neo-Inositol*scyllo-Inositol...
-, D-chiro
D-chiro-inositol
D-chiro-Inositol is a member of a family of related substances often referred to collectively as "inositol," although that term encompasses several isomers of questionable biological relevance...
-, and neo-inositol
Neo-inositol
neo-Inositol is one of the stereoisomers of inositol.-See also:*allo-Inositol*cis-Inositol*D-chiro-Inositol*L-chiro-Inositol*epi-Inositol*muco-Inositol*scyllo-Inositol...
. The other possible isomers are L-chiro
L-chiro-inositol
L-chiro-Inositol is one of the isomers of inositol.-See also:*allo-Inositol*cis-Inositol*D-chiro-Inositol*epi-Inositol*muco-Inositol*neo-Inositol*scyllo-Inositol...
-, allo
Allo-inositol
Allo-inositol is a stereoisomer of inositol.-See also:*cis-Inositol*D-chiro-Inositol*L-chiro-Inositol*epi-Inositol*muco-Inositol*neo-Inositol*scyllo-Inositol...
-, epi
Epi-inositol
epi-Inositol is one of the stereoisomers of inositol.-See also:*allo-Inositol*cis-Inositol*D-chiro-Inositol*L-chiro-Inositol*muco-Inositol*neo-Inositol*scyllo-Inositol...
-, and cis-inositol
Cis-inositol
cis-Inositol is one of the isomers of inositol.-See also:*allo-Inositol*D-chiro-Inositol*L-chiro-Inositol*epi-Inositol*muco-Inositol*neo-Inositol*scyllo-Inositol...
. As their name denotes, the two chiro inositols are the only pair of inositol enantiomers, but they are enantiomers of each other, not of myo-inositol.
 | |||
| myo- | scyllo- | muco- | chiro- |
| neo- | allo- | epi- | cis- |
In its most stable conformational geometry, the myo-inositol isomer assumes the chair conformation
Cyclohexane conformation
A cyclohexane conformation is any of several three-dimensional shapes that a cyclohexane molecule can assume while maintaining the integrity of its chemical bonds....
, which puts the maximum number of hydroxyls to the equatorial position, where they are farthest apart from each other. In this conformation the natural myo isomer has a structure in which five of the six hydroxyl
Hydroxyl
A hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...
s (the 1st, 3rd, 4th, 5th, and 6th are equatorial
Equatorial
Equatorial may refer to:* Equator of the Earth* Equatorial climate in meteorology* The ring-shaped outer boundary of the cross-section of a round three dimensional shape or object in geometry* The equatorial bond of a molecule in chemistry...
, whereas the 2nd hydroxyl group is axial
Axial
Axial may mean:* Along the same line as an axis of rotation in geometry* A type of modal frame in music* One of several anatomical directions in an animal body* Axial age, the period from 800 to 200 BC in China, India and the western world...
.
Synthesis
Myo-Inositol is synthesized from glucose-6-phosphateGlucose-6-phosphate
Glucose 6-phosphate is glucose sugar phosphorylated on carbon 6. This compound is very common in cells as the vast majority of glucose entering a cell will become phosphorylated in this way....
(G-6-P) in two steps. First, G-6-P is isomer
Isomer
In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...
ised by an inositol-3-phosphate synthase
Inositol-3-phosphate synthase
In enzymology, an inositol-3-phosphate synthase is an enzyme that catalyzes the chemical reactionHence, this enzyme has one substrate, D-glucose 6-phosphate, and one product, 1D-myo-inositol 3-phosphate....
enzyme (called ISYNA1) to myo-inositol 1-phosphate, which is then dephosphorylated by an Inositol monophosphatase
Inositol monophosphatase
Inositol monophosphatase , commonly referred to as IMPase, is an enzyme found in all cells and is thought to be key in bipolar disorder...
enzyme (called IMPase 1) to give free myo-inositol. In humans most inositol is synthesized in the kidneys, in typical amounts of a few grams per day.
Function
Inositol and a number of its mono and polyphosphates function as the basis for a number of signaling and secondary messenger molecules. They are involved in a number of biological processes, including:- InsulinInsulinInsulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
signal transductionSignal transductionSignal transduction occurs when an extracellular signaling molecule activates a cell surface receptor. In turn, this receptor alters intracellular molecules creating a response... - CytoskeletonCytoskeletonThe cytoskeleton is a cellular "scaffolding" or "skeleton" contained within a cell's cytoplasm and is made out of protein. The cytoskeleton is present in all cells; it was once thought to be unique to eukaryotes, but recent research has identified the prokaryotic cytoskeleton...
assembly - Nerve guidance (EpsinEpsinEpsins are the family of membrane proteins that are important in creating the needed membrane curvature. Epsins contribute to various needed membrane deformations like endocytosis and block vesicle formation during mitosis. Epsins have many different domains to interact with various proteins...
) - IntracellularIntracellularNot to be confused with intercellular, meaning "between cells".In cell biology, molecular biology and related fields, the word intracellular means "inside the cell".It is used in contrast to extracellular...
calciumCalciumCalcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
(Ca2+) concentration control - Cell membrane potentialMembrane potentialMembrane potential is the difference in electrical potential between the interior and exterior of a biological cell. All animal cells are surrounded by a plasma membrane composed of a lipid bilayer with a variety of types of proteins embedded in it...
maintenance - SerotoninSerotoninSerotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
activity modulation - Breakdown of fatFatFats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
s and reducing blood cholesterolCholesterolCholesterol 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... - Gene expressionGene expressionGene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...
Phytic acid in plants
Phytic acidPhytic acid
Phytic acid is the principal storage form of phosphorus in many plant tissues, especially bran and seeds. Phytate is not digestible to humans or nonruminant animals, however, so it is not a source of either inositol or phosphate if eaten directly...
, which is inositol hexakisphosphate (IP6), also known as phytate when in salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
form, is the principal storage form of phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
in many plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
tissue
Biological tissue
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
s, especially bran
Bran
Bran is the hard outer layer of grain and consists of combined aleurone and pericarp. Along with germ, it is an integral part of whole grains, and is often produced as a by-product of milling in the production of refined grains. When bran is removed from grains, the grains lose a portion of their...
and seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s. Neither the inositol nor the phosphate in phytic acid in plants is available to humans, or to animals who are not ruminants, since it cannot be broken down, except by bacteria. Moreover, phytic acid also chelates important minerals such as calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
, magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
, iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
, and zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, making them unabsorbable, and contributing to mineral deficiencies in people whose diets rely high bran and seed diets for their mineral intake, such as occurs in developing countries.
Inositol penta- (IP5), tetra- (IP4), and triphosphate (IP3) are also called "phytates."
Explosive potential
At the 1936 meeting of the American Chemical SocietyAmerican Chemical Society
The American Chemical Society is a scientific society based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has more than 161,000 members at all degree-levels and in all fields of chemistry, chemical...
, professor Edward Bartow of the University of Iowa
University of Iowa
The University of Iowa is a public state-supported research university located in Iowa City, Iowa, United States. It is the oldest public university in the state. The university is organized into eleven colleges granting undergraduate, graduate, and professional degrees...
presented a commercially viable means of extracting large amounts of inositol from waste corn. As a possible use for the chemical, he suggested inositol nitrate as a more stable alternative to nitroglycerin. Today, inositol nitrate is used to gelatinize nitrocellulose
Nitrocellulose
Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...
, and thus can be found in many modern explosives and solid rocket propellants.
Psychiatric conditions
Some preliminary results of studies on high-dose inositol supplements show promising results for people suffering from problems such as bulimia, panic disorderPanic disorder
Panic disorder is an anxiety disorder characterized by recurring severe panic attacks. It may also include significant behavioral change lasting at least a month and of ongoing worry about the implications or concern about having other attacks. The latter are called anticipatory attacks...
, obsessive-compulsive disorder
Obsessive-compulsive disorder
Obsessive–compulsive disorder is an anxiety disorder characterized by intrusive thoughts that produce uneasiness, apprehension, fear, or worry, by repetitive behaviors aimed at reducing the associated anxiety, or by a combination of such obsessions and compulsions...
, agoraphobia
Agoraphobia
Agoraphobia is an anxiety disorder defined as a morbid fear of having a panic attack or panic-like symptoms in a situation from which it is perceived to be difficult to escape. These situations can include, but are not limited to, wide-open spaces, crowds, or uncontrolled social conditions...
, and unipolar
Clinical depression
Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...
and bipolar depression.
In a single double-blind
Double-blind
A blind or blinded experiment is a scientific experiment where some of the people involved are prevented from knowing certain information that might lead to conscious or subconscious bias on their part, invalidating the results....
study on 13 patients, Myo-inositol (18 grams daily) has been found to reduce the symptoms of obsessive-compulsive disorder
Obsessive-compulsive disorder
Obsessive–compulsive disorder is an anxiety disorder characterized by intrusive thoughts that produce uneasiness, apprehension, fear, or worry, by repetitive behaviors aimed at reducing the associated anxiety, or by a combination of such obsessions and compulsions...
(OCD) significantly, with effectiveness equal to SSRIs and virtually without side-effects. In a double-blind, controlled trial, myo-inositol (18 grams daily) was superior to fluvoxamine
Fluvoxamine
Fluvoxamine is an antidepressant which functions as a selective serotonin reuptake inhibitor . Fluvoxamine was first approved by the U.S. Food and Drug Administration in 1993 for the treatment of obsessive compulsive disorder . Fluvoxamine CR is approved to treat social anxiety disorder...
for decreasing the number of panic attacks and other side-effect
Adverse effect
In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery.An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. If it results from an unsuitable or incorrect dosage or...
s.
Patients suffering from clinical depression
Clinical depression
Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...
, in general, have decreased levels of inositol in their cerebrospinal fluid
Cerebrospinal fluid
Cerebrospinal fluid , Liquor cerebrospinalis, is a clear, colorless, bodily fluid, that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord...
. A double-blind, placebo
Placebo
A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...
-controlled study of depressed patients showed that a high dose of inositol (12 grams daily) resulted in significant improvement of symptoms, with no changes noted in 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...
, kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
, or hematological
Hematology
Hematology, also spelled haematology , is the branch of biology physiology, internal medicine, pathology, clinical laboratory work, and pediatrics that is concerned with the study of blood, the blood-forming organs, and blood diseases...
function. A meta-analysis of randomized trials of inositol for depression was not able to determine if inositol is of benefit.
Older research suggests that lithium functions primarily by decreasing myo-inositol concentrations in bipolar patients; however the conclusions of this research are unsupported and have been questioned. Other studies suggest that lithium treatment may further inhibit the enzyme inositol monophosphatase
Inositol monophosphatase
Inositol monophosphatase , commonly referred to as IMPase, is an enzyme found in all cells and is thought to be key in bipolar disorder...
, leading to higher intracellular levels of inositol triphosphate
Inositol triphosphate
Inositol trisphosphate or inositol 1,4,5-trisphosphate , together with diacylglycerol , is a secondary messenger molecule used in signal transduction and lipid signaling in biological cells. While DAG stays inside the membrane, IP3 is soluble and diffuses through the cell...
, an effect that was enhanced further by administration of an inositol triphosphate reuptake inhibitor
Reuptake inhibitor
A reuptake inhibitor , also known as a transporter blocker, is a drug that inhibits the plasmalemmal transporter-mediated reuptake of a neurotransmitter from the synapse into the pre-synaptic neuron, leading to an increase in the extracellular concentrations of the neurotransmitter and therefore an...
.
Other conditions
D-chiro-inositolD-chiro-inositol
D-chiro-Inositol is a member of a family of related substances often referred to collectively as "inositol," although that term encompasses several isomers of questionable biological relevance...
(DCI) has been found in two double-blind studies to be an effective treatment for many of the clinical hallmarks of polycystic ovary syndrome
Polycystic ovary syndrome
Polycystic ovary syndrome is one of the most common female endocrine disorders. PCOS is a complex, heterogeneous disorder of uncertain aetiology, but there is strong evidence that it can to a large degree be classified as a genetic disease....
(PCOS), including insulin resistance
Insulin resistance
Insulin resistance is a physiological condition where the natural hormone insulin becomes less effective at lowering blood sugars. The resulting increase in blood glucose may raise levels outside the normal range and cause adverse health effects, depending on dietary conditions. Certain cell types...
, hyperandrogenism
Hyperandrogenism
Hyperandrogenism is a medical condition characterized by excessive production and/or secretion of androgens.It is one of the primary symptoms of polycystic ovary syndrome. In such cases, it presents with symptoms such as acne or hyperseborrhea, is frequent in adolescent girls and is often...
, and oligo-amenorrhea; the impetuses for these studies were the observed defects in DCI metabolism in PCOS and the implication of DCI in insulin signal transduction. Another small, placebo-controlled study has demonstrated that myo-inositol supplementation improves features of dysmetabolic syndrome in post-menopausal women, including triglycerides, HDL cholesterol, and diastolic blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
.
Animal studies suggest inositol reduces the severity of the osmotic demyelination syndrome if given prior to rapid correction of chronic hyponatraemia. Further study is required prior to its application in humans for this indication.
Studies from 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...
experiments, animal studies, and limited clinical experiences, claim that inositol may be used effectively against some types of cancer, in particular, when used in combination with phytic acid
Phytic acid
Phytic acid is the principal storage form of phosphorus in many plant tissues, especially bran and seeds. Phytate is not digestible to humans or nonruminant animals, however, so it is not a source of either inositol or phosphate if eaten directly...
.
Common use as a "cutting" agent
Inositol has been used as an adulterantCutting agent
A cutting agent is a chemical used to "cut" illicit drugs with something less expensive than the drug itself.-Overview:The classical model of drug cutting A cutting agent is a chemical used to "cut" (dilute) illicit drugs with something less expensive than the drug itself.-Overview:The classical...
(or cutting agent) in many illegal drugs, such as cocaine
Cocaine
Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
, methamphetamine
Methamphetamine
Methamphetamine is a psychostimulant of the phenethylamine and amphetamine class of psychoactive drugs...
, and sometimes heroin. It is presumed that this use is connected with the substance's solubility and near-lack of taste.
Nutritional sources
Myo-inositol is naturally present in a variety of foods, although tables of this do not always distinguish between the bioavailable lecithinLecithin
Lecithin is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues, and in egg yolk, composed of phosphoric acid, choline, fatty acids, glycerol, glycolipids, triglycerides, and phospholipids .The word lecithin was originally coined in 1847 by...
form, and the non-available phytate form in grains. According to research, foods containing the highest concentrations of myo-inositol (including its compounds) include fruits, beans, grains and nuts. Beans and grains, however, as seeds contain large amounts of inositol as phytate.
See also
- Allo-inositolAllo-inositolAllo-inositol is a stereoisomer of inositol.-See also:*cis-Inositol*D-chiro-Inositol*L-chiro-Inositol*epi-Inositol*muco-Inositol*neo-Inositol*scyllo-Inositol...
- Cis-inositolCis-inositolcis-Inositol is one of the isomers of inositol.-See also:*allo-Inositol*D-chiro-Inositol*L-chiro-Inositol*epi-Inositol*muco-Inositol*neo-Inositol*scyllo-Inositol...
- D-chiro-inositolD-chiro-inositolD-chiro-Inositol is a member of a family of related substances often referred to collectively as "inositol," although that term encompasses several isomers of questionable biological relevance...
- Epi-inositolEpi-inositolepi-Inositol is one of the stereoisomers of inositol.-See also:*allo-Inositol*cis-Inositol*D-chiro-Inositol*L-chiro-Inositol*muco-Inositol*neo-Inositol*scyllo-Inositol...
- L-chiro-inositolL-chiro-inositolL-chiro-Inositol is one of the isomers of inositol.-See also:*allo-Inositol*cis-Inositol*D-chiro-Inositol*epi-Inositol*muco-Inositol*neo-Inositol*scyllo-Inositol...
- Muco-inositolMuco-inositolmuco-Inositol is one of the stereoisomers of inositol.-See also:*allo-Inositol*cis-Inositol*D-chiro-Inositol*L-chiro-Inositol*epi-Inositol*neo-Inositol*scyllo-Inositol...
- Neo-inositolNeo-inositolneo-Inositol is one of the stereoisomers of inositol.-See also:*allo-Inositol*cis-Inositol*D-chiro-Inositol*L-chiro-Inositol*epi-Inositol*muco-Inositol*scyllo-Inositol...
- Scyllo-inositolScyllo-inositolscyllo-Inositol is one of the stereoisomers of inositol. It is also known as scyllitol, cocositol, quercinitol, and 1,3,5/2,4,6-hexahydroxycyclohexane...
- Inositol 1-methyltransferaseInositol 1-methyltransferaseIn enzymology, an inositol 1-methyltransferase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are S-adenosyl methionine and myo-inositol, whereas its two products are S-adenosylhomocysteine and 1D-1-O-methyl-myo-inositol.This enzyme belongs to the family...
- Inositol 3-methyltransferaseInositol 3-methyltransferaseIn enzymology, an inositol 3-methyltransferase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are S-adenosyl methionine and myo-inositol, whereas its two products are S-adenosylhomocysteine and 1D-3-O-methyl-myo-inositol.This enzyme belongs to the family...
- Inositol 4-methyltransferaseInositol 4-methyltransferaseIn enzymology, an inositol 4-methyltransferase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are S-adenosyl methionine and myo-inositol, whereas its two products are S-adenosylhomocysteine and 1D-4-O-methyl-myo-inositol.This enzyme belongs to the family...
- Inositol nicotinateInositol nicotinateInositol nicotinate is a vasodilator.Inositol Nicotinate is given the term Inositol hexaniacinate, as well as "No-Flush Niacin". "Flushing", in physiology, is a broad term that essentially means that epidermal tissues have become reddened, such as when the skin is irritated from the histamine...
- Inositol phosphateInositol phosphateInositol phosphates are a group of mono- to polyphosphorylated inositols. They play crucial roles in diverse cellular functions, such as cell growth, apoptosis, cell migration, endocytosis, and cell differentiation.The group comprises:...
- Inositol trisphosphate
- Inositol pentakisphosphateInositol pentakisphosphateInositol pentakisphosphate is a molecule derived from inositol tetrakisphosphate by adding a phosphate group with the help of inositol polyphosphate multikinase . It is believed to be one of the many second messengers in the inositol phosphate family...
- Inositol hexaphosphate
- Inositol triphosphate receptorInositol triphosphate receptorInositol trisphosphate receptor is a membrane glycoprotein complex acting as Ca2+ channel activated by inositol trisphosphate . InsP3R is very diverse among organisms, and is necessary for the control of cellular and physiological processes including cell division, cell proliferation, apoptosis,...
- Inositol hexanicotinate
- Essential nutrientEssential nutrientAn essential nutrient is a nutrient required for normal body functioning that either cannot be synthesized by the body at all, or cannot be synthesized in amounts adequate for good health , and thus must be obtained from a dietary source...
- HyperuricemiaHyperuricemiaHyperuricemia is a level of uric acid in the blood that is abnormally high. In humans, the upper end of the normal range is 360 µmol/L for women and 400 µmol/L for men.-Causes:...
- HypouricemiaHypouricemiaHypouricemia is a level of uric acid in blood serum that is below normal. In humans, the normal range of this blood component has a lower threshold set variously in the range of 2 mg/dL to 4 mg/dL, while the upper threshold is 530 micromol/L for women and 619 micromol/L for men...