Crocin is a

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

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 perennial plant, perennials growing from corms. They are low growing plants, whose flower stem ...

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, Pacific Islands, and Australia. The genus was named by Carl Linnaeus and John Ellis after ...

. Its oxygen content also chemically makes it a

xanthene Xanthene (9''H''-xanthene, 10''H''-9-oxaanthracene) is the organic compound with the formula CH2 6H4sub>2O. It is a yellow solid that is soluble in common organic solvents. Xanthene itself is an obscure compound, but many of its derivatives are u ...

. 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 and styles, called threads, are collected and dried for use mainly as a seasoning and colouring agent ...

. Chemically, crocin is the diester 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, ...

gentiobiose and the branched-chain dicarboxylic acid

crocetin Crocetin is a natural apocarotenoid dicarboxylic acid, a diterpenoid, and a branched-chain dicarboxylic acid. It was the first plant carotenoid to be recognized as early as 1818 while the history of saffron cultivation reaches back more than 3 ...

. 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 polyunsaturated organic compounds that contain multiple carbon–carbon double bonds (). Some sources consider dienes to be polyenes, whereas others require polyenes to contain at least three carbon–carbon d ...

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 acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

; 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 membrane, semipermeable border of endothelium, endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system ...

Antioxidant

Crocin has been shown to be an

antioxidant Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...

, and neural protective agent. Crocin can reduce oxidative stress and ROS (

Reactive Oxygen Species In chemistry and biology, reactive oxygen species (ROS) are highly Reactivity (chemistry), reactive chemicals formed from diatomic oxygen (), water, and hydrogen peroxide. Some prominent ROS are hydroperoxide (H2O2), superoxide (O2−), hydroxyl ...

) 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 Alzheimer's disease (AD) is a neurodegenerative disease and the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems wit ...

and

Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...

. 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 action against cancer cells ''

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

''. 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 libido, sexual desire, sexual attraction, sexual pleasure, or sexual behavior. These substances range from a variety of plants, spices, and foods to synthetic chemicals. Natural aphrodisiacs, such as ...

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

Retinal diseases

Emerging evidence highlights the cytoprotective, antioxidative, and anti-inflammatory potential of crocin in

retinal Retinal (also known as retinaldehyde) is a polyene chromophore. Retinal, bound to proteins called opsins, is the chemical basis of visual phototransduction, the light-detection stage of visual perception (vision). Some microorganisms use ret ...

tissue, which positions it as a promising candidate for enhancing vision and

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

health. Nevertheless, it's important to note that the majority of research has primarily focused on animal models, and there remains a shortage of robust clinical data to firmly establish the benefits of crocin in addressing eye health and related diseases.

References

Bibliography

External links

* {{Carotenoids Carotenoid glycosides Dietary antioxidants Food colorings Saffron