Cynara scolymus L.

1. CLASSIFICATION

Kingdom : Plantae (Plants)

Subkingdom : Tracheobionta (Vascular plants)

Superdivision : Spermatophyta (Seed plants)

Division: Magnoliophyta (Flowering plants)

Class: Magnoliopsida (Dicotyledons)

Subclass : Asteridae

Order: Asterales

Family : Compositae = Asteraceae  (Sunflower Family)

Tribe : Cardueae

Genus : Cynara L.

Species : Cynara scolymus L.

Synonyms :

·         Cynara cardunculus (after some authors)

Related Species :

·         Cynara cardunculus, “alcachofa silvestre”

·         Silybum marianum, “cardo mariano”

Common Names : “artichoke”, “ globe artichoke”, “ artichoke plant”, “globe thistle”.Castilian/Spanish: “alcachofa”, “alcachofero”, “alcachofera”. Portuguese: “alcachofra”. Italian: articiocco. Others: “artichaut”, “tyosen-azami”.

2. DESCRIPTION

Habit : Herbaceous plant. Its stem can reach up to 2 m in height and divides in branches that bear flowers at their apex. Lateral branches spread radially up to 1 m.

Leaves : Emerge from the stem base; they are large and somewhat thorny.

Flowers : They are disposed in big globular terminal capitula (heads), violet-colored, blue-colored, or white-colored. The flower heads can reach up to 15 cm. They are very similar to those of some thistle. Involucre is dilated, imbricate, and thorny. Numerous ovate scales enclose the floscula (flowers). These floscula are inserted in a wide receptacle. The blossoms receive the name of artichoke; they are edible.

Fruit : Not described.

3. ORIGIN, DISTRIBUTION AND ECOLOGY

Origin : Cynara scolymus L. is considered a cultigen native to the Mediterranean basin, probably a derivative of Cynara carduncellus, a plant species also native to South Europe and North Africa.

Distribution : Cynara scolymus L. grows in the wild in Southern Europe and is cultivated in this continent and the United States, especially in California. In Peru, Cynara scolymus L. is being successfully cultivated in the Central Sierra. Cynara scolymus L. is widely cultivated for its enormous edible flower-heads

Ecology : Cynara scolymus L. withers in summer but revives in autumn. This plant species flowers in spring.

4. HISTORY

Cynara scolymus L. was already cultivated by ancient Egyptians, Greeks, and Romans. In Roma, it was an important delicatessen, very estimated, especially during holidays, due to its agreeable bitter flavor. In spite of that, its diffusion to the rest of Europe delayed up to the 15^th century. Since several hundred years ago, Cynara scolymus L. has been used in traditional medicine both, in Europe and in other parts of the world, in order to treat gallbladder and liver diseases.

In England, where Cynara scolymus L. was considered an aristocratic vegetable, it is being cultivated since, at least, 16^th century. It is said that king Henry the 8^th, who had 6 wives and only 3 children, had a particular taste for Cynara scolymus L., possibly due to the fact that this plant species was then considered –erroneously—an aphrodisiac.

Some homemade snakebite antidotes of the Old World also include Cynara scolymus L. among their ingredients (Ruppelt, 1991). Effectively, Cynara scolymus L. protects liver from venomous effects of some toxins the same way silymarin, a compound obtained from the Marian thistle, does. The antidote range for Cynara scolymus L. is similar to that of the Marian thistle.

When Europeans arrived to the New World, Cynara scolymus L. settled with them. Hence, in Brazilian Folk Medicine, a preparation based on its leaves is used in order to treat liver and gallbladder diseases, as well as diabetes, hypercholesterolemia, hypertension, anemia, diarrhea, fever, ulcers and gout. Cynara scolymus L. is also used in Dominican Republic, Haitian, and Mexican folk medicines in order to treat very similar diseases.

In the 1970’s decade, European scientists performed the very first serious experiments related to cynarin, the major active ingredient in Cynara scolymus L. Hence, its capacity for diminishing human blood cholesterol levels was documented for the first time. More recent studies suggest that there are other phytochemical compounds, apart from cynarin, that would be equally responsible for the diminishing of blood cholesterol levels.

Today, several countries around the world produce commercial prescription drugs based on Cynara scolymus L. These drugs are used in order to combat high blood cholesterol levels and cure digestive and hepatic diseases, as well as chronic albuminuria, dyspepsia, and renal insufficiency.

A common use attributed to Cynara scolymus L. around the world is against liver and gallbladder diseases. This plant species is considered cholagogue, choleretic, and choliokinetic. Cynara scolymus L. is also used in order to mobilize fats stored in the liver and hence detoxifies the liver, and as a natural help for reducing cholesterol blood levels. Cynara scolymus L. is currently marketed as tincture, although it is also sold as capsules, tablets, and water dilution.

Nowadays, we can affirm that some of the curative properties that folk knowledge empirically attributed to Cynara scolymus L. have been confirmed. What still remains for scientific study is simply discover which is or which are the chemical compounds responsible of this or that property. The ability of Cynara scolymus L. in order to reduce cholesterol blood levels, as well as for treating liver, gallbladder and stomach diseases is being confirmed.

In Europe, concentrated extract of Cynara scolymus L. are sold by medical prescription, although in the United States they are sold freely in healthy food stores. Due to the tendency in the world of today for electing natural and healthier solutions for human diseases, as well as the not so much healthy modern diet, Cynara scolymus L. extracts are very probable to begin to gain popularity.

acne, anemia, arteriosclerosis, bronchitis, cystitis, dropsy, gallbladder disorders & stones, gout, hemorrhoids, hypertension, obesity, prostatitis, seborrheasis, ulcers, urethritis, urinary diseases, arthritic, asthmatic, anti dandruff, anti diabetic, anti diarrheic, anti emetic, anti flatulent, anti hemorrhagic, anti nephritic, anti rheumatic, anti uremic, anticancerous, antihypertensive, antioxidante, astringent, capillary tonic, cardiotonic, cholagogue (increases bile production in the liver), choleretic (increases bile flux from the gallbladder), choliokinetic (increases contractions of the biliary conduct), depurative, detoxifier, diuretic, dyspepsia, febrifuge, Food (its tender inflorescence is a much appreciated delicatessen with a high content of iron), haemostatic, hepatic, hepatoprotector, hypocholesterolemic (cholesterol blood level reducer), hypoglycemic, hypotensive, inflammation, jaundice, stimulant, vasoconstrictor

The first experiment demonstrating in rats protective and detoxifier properties of Cynara scolymus L. in liver was conducted in 1966. Adzet (1987) determined that cynarin –and in less degree, caffeic acid—obtained from Cynara scolymus L. protected rat hepatocytes against toxicity produced by carbon tetrachloride (CCl₄ ). In other treatments, caffeic acid resulted as effective as pure cynarin.

More recently (2002), a leaf extract obtained from Cynara scolymus L. was demonstrated to be able to revert damage caused by noxious chemicals on cell membranes in rat liver cells, by which bile production was increased. Some studies have shown that an extract obtained from Cynara scolymus L. can increase bile volume by four times its normal value within 12 hours. It is also known that leaf extract has the ability to stimulate liver cell regeneration, the same way as silymarin does, a compound obtained from the Marian thistle.

In a study carried out with men, Woyke (1981) showed that a commercial extract of Cynara scolymus L., called Cynarex, had the property to reduce platelet aggregation when taken during two years.

In Brazil, Cynara scolymus L. is used as diuretic due to its property to eliminate uric acid from the system. Cynara scolymus L. is also used in order to cure liver diseases, especially those associated with malaria and alcoholism. In general, Brazilian herbal medicine attributes Cynara scolymus L. the property of cleansing and purify both liver and gallbladder.

Cynara scolymus L. is also a good food. Its high iron content invigorates blood. In Spain, Cynara scolymus L. is among the 9 major vegetables as source of carotenoids (Granado, 1996). Gibson (1998) has shown that Cynara scolymus L. is among the probiotic foods; this means that Cynara scolymus L. promotes the development of the colonic flora (bifidobacteria, lactobacilli, etc.).

The employment of extracts obtained from Cynara scolymus L. in order to treat digestive diseases is very well documented. Its curative power extends to all the digestive tract, from esophagus to colon, including its annexed organs, such as liver and gallbladder. In 1999 a clinic study focused on the function of gallbladder was conducted. This study showed the efficacy and safety of extracts from Cynara scolymus L. for the treatment of hepato-biliary and digestive dysfunctions, such as heaviness, lack of hunger, nausea, and abdominal pain.

In 2000, other study focused on the irritable colon syndrome. This syndrome’s symptoms are very similar to dyspepsia, a digestive disorder which involves esophagus, duodenum, and the upper gastrointestinal tract. Although the extract of Cynara scolymus L. was known to be useful in order to treat dyspepsia, researchers wanted to find out if this treatment was also valuable against this syndrome. Hence, a leaf extract from Cynara scolymus L. was administered to a group of patients with this syndrome; these patients where then observed for six months. The results indicated that 96% of the patients with the syndrome of irritable colon considered the extract better or at least equal than the therapies they were receiving in order to treat their disease.

Some homemade antidotes against poisonous snakebites with anti-inflammatory or analgesic properties in mice include Cynara scolymus L. among their ingredients (Ruppelt, 1991).

Dehydrated Cynara scolymus L. is known to produce an increase in flavor of foods. So treated Cynara scolymus L. is also known to produce a sweet tasting when mixed in water.

According to Brown (1998), the extract of Cynara scolymus L., rich in luteolin, inhibits peroxydation of lipids.

Gebhardt (1998) determined that a water extract of Cynara scolymus L. leaves inhibited proportionally cholesterol biosynthesis at concentration of 0.007 mg/mL to 0.1 mg/mL. Moreover, this water leaf-extract inhibits HMG CoA-reductase activity in hepatocytes.

From Cynara scolymus L. an antioxidant flavonoid has been isolated. This antioxidant flavonoid, when applied to mice at concentrations of 0.5 mg to 18 mg per each mouse, inhibited ornitin decarboxilase activity induced by TPA (Agarwal, 1994).

Although during medieval times in Europe Cynara scolymus L. was thought to have the capacity to increase sexual potency, researches performed in male rats determined that there was no significant change in their seminal structure when they were treated with 35.7 mg/kg and 150 mg/kg of a Cynara scolymus L. extract, 5 times a week, during 75 days (Ilieva, 1994).

The use of polyphenols present in Cynara scolymus L. has also been proposed as a preventive chemical against cancer (Agarwal, 1996). Likewise, a flavonoid obtained from Cynara scolymus L. has been proposed as dietetic supplement in order to prevent cancer (Mukhtar, 1996).

Akihisa (1996) points out that triterpenic alcohols from Cynara scolymus L. reduce inflammation induced by TPA. Yasukawa has shown that at a concentration of 2 micromoles per mouse, taraxasterol (taraxastan-type hydroxitriterpene) obtained from flowers of Cynara scolymus L. inhibited fomation of TPA- or DMBA-induced tumors.

According to Khalkova (1995), catecholamines increased by carbon bisulphur return to their normal levels in rats when an extract of Cynara scolymus L. is administered at concentration of 200 mg/kg of body weight.

In a study carried out in 2000 in order to inquire for properties of cynarin obtained from a leaf extract of Cynara scolymus L., following the methodology known as ‘double blinded’, this extract or a placebo was randomly administered during 6 weeks to 143 individuals with high blood levels of cholesterol. The results showed a diminishing of between 10% and 15% of total cholesterol, LDL cholesterol (bad cholesterol), and LDL-cholesterol/HDL-cholesterol ratio, at the end of the experiment.

Today we know that the reducing effect on cholesterol blood level is not exclusive of cynarin. This effect is shared by other chemical compounds also present in Cynara scolymus L., including some recently discovered. These effects could be due to the capacity of the leaf extract to protect liver from toxins such as alcohol, which increases cholesterol blood level. Moreover, leaf extract reduces cholinesterase levels.

It seems like the net effect of Cynara scolymus L. extract is the result of both the activation and the interference of cholesterol metabolism. In conclusion, the extract mobilizes spare fat from liver and other tissues, such as white adipose tissue, towards blood, and from there this fat is subsequently excreted out of the body.

Cynarin diminishes the rate of cholesterol synthesis in the liver, powers biliary excretion of cholesterol and increases its conversion toward biliary acids. In that sense, it not only reduces cholesterol levels, but also reduces levels of other lipids in blood, such as triglycerides.

Some beneficial properties of Cynara scolymus L. are attributable to its proved antioxidant quality. Effectively, a 2000 study performed on human blood leukocytes of individuals subjected to a series of oxidative stresses, determined that the leaf extract had antioxidant properties. In other similar study conducted in 2002 and focused on the antioxidant power of this extract on endothelial cells of blood vessels cultured in vitro , the extract was reported to have remarkable protective properties against oxidative stress induced by inflammatory substances.

Plant Chemicals :

acid linoleic, acid miristic, acid oleic, apigenin, caffeic acid, caffeoilquinic acids, cariophyllene, carotenoids, clorogenic acid, cosmosid, cyanidolic glycosides, cynaragenin, cynarapicrin, cynaratriol, cynarin (1, 5-dicaphenil ester of quinic acid), cynarolide, cynarosids, decanal, escolimosid, escopoletin, esculetin, eugenol, ferulic acid, flavonoids, folacin, glyceric acid, glycolic acid, hesperidosid, hesperitine, heterosid B, inulin, isoamerboin, isochlorogenic acid, lauric acid, linolenic acid, luteolin (and its 4'-glycosid & 7-gentiobiosid), luteolinic glycosides, maritimein, neochlorogenic acid, palmitic acid, phenylacetaldehid, polyphenols, pseudotaraxasterol, quercetin, rutin, sesquiterpenic, lactones, silymarin, sitosterol, stearic, acid, stigmasterol, taraxasterol, triterpenic alcohols