Crocin is a

carotenoid Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, ...

chemical compound that is found in the flowers of

crocus ''Crocus'' (; plural: crocuses or croci) is a genus of seasonal flowering plants in the family Iridaceae (iris family) comprising about 100 species of perennials growing from corms. They are low growing plants, whose flower stems remain under ...

and

gardenia ''Gardenia'' is a genus of flowering plants in the coffee family, Rubiaceae, native to the tropical and subtropical regions of Africa, Asia, Madagascar and Pacific Islands, and Australia. The genus was named by Carl Linnaeus and John Ellis af ...

. Crocin is the chemical primarily responsible for the color of

saffron Saffron () is a spice derived from the flower of ''Crocus sativus'', commonly known as the "saffron crocus". The vivid crimson stigma (botany), stigma and stigma (botany)#style, styles, called threads, are collected and dried for use mainly ...

. Chemically, crocin is the

diester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are ...

formed from the

disaccharide A disaccharide (also called a double sugar or ''biose'') is the sugar formed when two monosaccharides are joined by glycosidic linkage. Like monosaccharides, disaccharides are simple sugars soluble in water. Three common examples are sucrose, la ...

gentiobiose and the

dicarboxylic acid In organic chemistry, a dicarboxylic acid is an organic compound containing two carboxyl groups (). The general molecular formula for dicarboxylic acids can be written as , where R can be aliphatic or aromatic. In general, dicarboxylic acids sho ...

crocetin Crocetin is a natural apocarotenoid dicarboxylic acid that is found in the crocus flower together with its glycoside, crocin, and ''Gardenia jasminoides'' fruits. It forms brick red crystals with a melting point of 285°C. The chemical structur ...

. When isolated as a pure chemical compound, it has a deep red color and forms crystals with a melting point of 186 °C. When dissolved in water, it forms an orange solution. The term ''crocins'' may also refer to members of a series of related

hydrophilic A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press. In contrast, hydrophobes are n ...

carotenoids that are either monoglycosyl or diglycosyl

polyene In organic chemistry, polyenes are poly- unsaturated, organic compounds that contain at least three alternating double () and single () carbon–carbon bonds. These carbon–carbon double bonds interact in a process known as conjugation, result ...

esters of crocetin. The crocin underlying saffron's aroma is α-crocin (a carotenoid pigment that may compose more than 10% of dry saffron's mass): trans-

di-(β-D- gentiobiosyl)

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...

; it bears the systematic (IUPAC) name 8,8-diapo-8,8-carotenoic acid. The major active component of saffron is the yellow pigment crocin 2 (three other derivatives with different glycosylations are known) containing a gentiobiose (disaccharide) group at each end of the molecule. The five major biologically active components of saffron, namely the four crocins and crocetin, can be measured with HPLC-UV.

Research

Absorption

Crocin ingested orally is hydrolised to crocetin in the gut which is absorbed across the intestinal barrier, and that crocetin can permeate the

Blood–brain barrier The blood–brain barrier (BBB) is a highly selective semipermeable border of endothelial cells that prevents solutes in the circulating blood from ''non-selectively'' crossing into the extracellular fluid of the central nervous system where ne ...

Antioxidant

Crocin has been shown to be an

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 lubrica ...

, and neural protective agent. Crocin can reduce oxidative stress and ROS (Reactive Oxygen Species) through enhancement of gene expression of Nrf2, HO-1, and anti-oxidant enzymes, such as CAT, GSH, and SOD.

Neuroprotective

Crocin and its derivative crocetin may counteract oxidative stress, mitochondrial dysfunction and neuroinflammation, which are closely linked to initiation and progression of major brain pathologies such as Alzheimer's and Parkinson's Disease. In an animal model of malathion-induced Parkinson's Disease, crocin reduced the neurotoxic effect of malathion by its anti-apoptotic activity and it regulated the expression of proteins involved in Parkinson's disease pathogenesis. Crocins can suppress the active forms of GSK3β and ERK1/2 kinases, significantly reducing tau phosphorylation, thus suppressing key molecular pathways of Alzheimer's Disease pathogenesis.

Mood

Crocin displays possible antidepressant properties in mice and humans.

Cancer

Crocin has also shown

antiproliferative Cytostasis (cyto – cell; stasis – stoppage) is the inhibition of cell growth and multiplication. Cytostatic refers to a cellular component or medicine that inhibits cell division. Cytostasis is an important prerequisite for structured multic ...

action against cancer cells ''

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called " test-tube experiments", these studies in biology a ...

''. and ''in vivo'' . Crocin through the PI3K/AKT/mTOR, MAPK, VEGF, Wnt/β-catenin, and JAK-STAT suppression has antiproliferative properties. Also, the Nrf2 and p53 signaling pathway activation may be effective in the antiproliferative effect of crocin.

Behavior

Aphrodisiac An aphrodisiac is a substance that increases sexual desire, sexual attraction, sexual pleasure, or sexual behavior. Substances range from a variety of plants, spices, foods, and synthetic chemicals. Natural aphrodisiacs like cannabis or cocai ...

properties of crocin in male rats has been observed at very high doses.

References

Bibliography

External links

* {{Carotenoids Carotenoid glycosides Dietary antioxidants Food colorings Saffron