No Need To Go Round The World When You Have Globe Artichoke

The Globe Artichoke has long been a culinary delight and in France and Italy has been raised to an artform in its cooking. The artichoke (Cynara cardunclus L. subsp. scolymus L. Hayek) from the family Asteraceae is an herbaceous perennial plant which is cultivated throughout Europe’s temperate climate. It produces large immature inflorescences (the capitula), fleshy leaves and a receptacle which are cooked and eaten.   It was originally grown in ancient times by both Greeks and Romans to aid digestion and ameliorate liver (hepatic) and kidney (renal) complaints. It is related to a similar vegetable, the cardoon.

The nutritional and therapeutic properties are related to the high levels of phenolics which are mostly mono- and di-isomers of caffeoylquinic acid and the flavonoid-O-glycosides of luteolin and apigenin (Pandino et al., 2011a&b; Schutz et al., 2004, 2006). The leaves contain  cynarin (1,3-dicaffeoylquinic acid) which has been associated with treating liver conditions ( an hepatoprotective effect).

The edible parts i.e. the receptacles with inner and intermediate bracts of artichoke are a strong source of health-promoting polyphenols and a suitable  alternative to the more traditional phytopharmaceutical applications of leaf extracts. There is considerable commercial interest in isolating the bioactives from waste leaves. An excellent review was written on this vegetable by Lattanzio et al., (2009) and subsequently by Ceccarelli et al., (2010). The leaves are commonly cooked until tender and the base is regarded as a delicacy. The ‘choke’ is not desirable to eat but can provide a fibre for further processing. For those of you interested in cooking them, then some useful links are to be found at:-

BBC Good Food: How to prepare globe artichokes.

Simply Recipes®..How too cook and eat an artichoke.

Traditional Globe Artichoke Cultivars Produced by Vegetative Propagation:

• Imperial Star
• Green, big: ‘Camus de Bretagne’, ‘Castel’ (France), ‘Green Globe’ (USA, South Africa)
• Green, medium-size: ‘Verde Palermo’ (Sicily), ‘Blanca de Tudela’ (Spain), ‘Argentina’, ‘Española’ (Chile), ‘Blanc d’Oran’ (Algeria), ‘Sakiz’, ‘Bayrampasha’ (Turkey)
• Purple, big: ‘Romanesco’, ‘C3’ (Italy)
• Purple, medium-size: ‘Violet de Provence’ (France), ‘Brindisino’, ‘Catanese’, ‘Niscemese’ (Sicily), ‘Violet d’Algerie’ (Algeria), ‘Baladi’ (Egypt), ‘Ñato’ (Argentina), ‘Violetta di Chioggia’ (Italy)
• Spined: ‘Spinoso Sardo e Ingauno’ (Sardinia), ‘Criolla’ (Peru).
• White, many places globally.

The artichoke has an extremely high antioxidant content.

Antioxidant Properties

The amount and types of compounds detected in artichoke extracts are influenced by the parts of the plant analysed as well as the variety in experimental parameters of sample extraction, work-up and detection methods. As in all studies the origin and growth conditions of the plant also play their part. Below are some examples in the development of antioxidant assessment.

A systematic antioxidant activity-directed fractionation procedure was used to purify antioxidative components from the aqueous methanol extractions of artichoke heads and leaves (specific areas not identified). Seven active polyphenolic compounds were purified, and the structures of each was elucidated with mass spectroscopy (MS) and nuclear magnetic resonance (NMR). Two unusual compounds, apigenin-7-rutinoside and narirutin, were found to be unique to the artichoke heads alone.  This was the first report of such compounds in the edible portion of this plant with potential for medical benefits. The contents of both antioxidant and total phenolics in dried artichoke samples from leaves and immature or mature heads of three cultivars, Imperial Star, Green Globe, and Violet, were also analyzed and compared using colorimetric and HPLC methods. Significant differences were observed in these  varieties and within the plant organ (Wang et al., 2003). This investigation on the localisation of antioxidants in different parts of the artichoke was later built on (Fratianni et al., 2007). Polyphenols from leaves and different parts (outer, intermediate and inner bracts, and receptacle) of heads in five globe artichoke cultivars of Campania region (Italy) and a cultivated cardoon were analysed.  It was demonstrated that single polyphenol types accumulate preferentially in specific parts of the heads and in specific genotypes.

Antimicrobial Properties

There is considerable interest in identifying the key parts of the plant with the highest levels of antioxidants and other polyphenols. A précis of the abstracts is given here and it would pay to look in closer detail at each article because of the differences in methods and cultivars used.

(1) A preliminary antimicrobial disk assay of chloroform, ethyl acetate, and n-butanol extracts of artichoke (Cynara scolymus L.) leaf extracts showed that the n-butanol fraction exhibited the most significant antimicrobial activities against seven bacteria species, four yeasts, and four molds. Eight phenolic compounds were isolated from the n-butanol soluble fraction of artichoke leaf extracts. On the basis of high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC-EIMS), tandem mass spectrometry (TMS), and nuclear magnetic resonance (NMR) techniques, the structures of the isolated compounds were  four caffeoylquinic acid derivatives, chlorogenic acid, cynarin, 3,5-di-O-caffeoylquinic acid, and 4,5-di-O-caffeoylquinic acid, and the four flavonoids, luteolin-7-rutinoside, cynaroside, apigenin-7-rutinoside, and apigenin-7-O-β-D-glucopyranoside. The isolated compounds were examined for their antimicrobial activities on a number of microorganisms, indicating that all eight phenolic compounds showed activity against most of the tested organisms. Among them, chlorogenic acid, cynarin, luteolin-7-rutinoside, and cynaroside exhibited a relatively higher activity than other compounds. In addition, they were more effective against fungi than bacteria. The minimum inhibitory concentrations of these compounds were between 50 and 200 μg/mL.

(2) A later study on the phenolic contents and antioxidant activity focussed on both organ and leaf phenolic compounds identification by RP-HPLC and their antibacterial activity (Falleh et al., 2008). The analyzed organs exhibited different total polyphenol contents (7–14.8 mg GAE g⁻¹ DW). Leaf and seed phenolic contents were similar and two times higher than those in flowers. The same tendency was observed for the amount of flavonoids and tannins. However, seed extracts displayed the highest DPPH^⋅ scavenging ability with the lowest IC₅₀ value (23 μg ml⁻¹), followed by leaves and flowers (over 50 μg ml⁻¹). In contrast, leaves showed the highest capacity to quench superoxide (IC₅₀: 1 μg ml⁻¹) as compared to seeds (6 μg ml⁻¹). In addition, cardoon leaves were efficient to inhibit growth of pathogenic bacteria mainly against Staphylococcus aureus and Escherichia coli. The identification of phenolic compounds from leaves revealed that syringic and trans-cinnamic acids were the major molecules. The distribution of polyphenols and antioxidants was more selectively measured in various tissues and developmental stages of  6 artichoke varietal types located around the Mediterranean (Negro et al., 2012). Flower heads were subdivided into external, intermediate, internal bracts, and receptacle, while leaves were collected at the vegetative and productive stages. The main polyphenols detected in this study were chlorogenic acid, cynarin, luteolin 7-O-rutinoside, and luteolin 7-O-glucoside. The cultivar “Violet de Provence” artichoke had the highest total phenol content. Single polyphenols accumulated preferentially in specific parts of the capitula. In leaves, most polyphenols were detected in the productive stage of the plant.

(3) The whole, fresh involucral bracts of cardoon, Cynara cardunculus L. (Compositae), were extracted with EtOH and an aqueous suspension of the obtained EtOH extract was partitioned successively with CHCl₃, EtOAc and n-BuOH, leaving a residual water extract (Kukić et al., 2008). These extracts were assessed for their antioxidant and antimicrobial properties. The antioxidant potential was evaluated using two in vitro methods: FRAP (ferric reducing antioxidant power) assay, and scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.

Antimicrobial activity was estimated using a microdilution technique against various food-borne, mycotoxin producers and human pathogenic bacteria and micromycetes. The following bacteria were tested: Salmonella typhimurium, Escherichia coli, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, as well as micromycetes: Aspergillus niger, Aspergillus ochraceus, Aspergillus flavus, Penicillium ochrochloron, P. funiculosum, Trichoderma viride, Fusarium tricinctum and Alternaria alternata. Results showed that all extracts possessed concentration-dependent antioxidant activity. In biological assays, C. cardunculus extracts showed antimicrobial activity comparable with standard antibiotics.”

The medicinal effects of artichoke extracts are the following:

♣ a liver (hepato-) protection effect (Adzet et al., 1987; Gebhardt and Fausel, 1997; Mehmetçik et al., 2008; Miccadei et al., 2008) attributed to the presence of luteolin, its glycoside luteolin-7-O-glucoside and caffeoylquinic acids, particularly 1,3-O-dicaffeoylquinic acid (cynarin) (Adzet et al., 1987; Gebhardt, 1997; Mehmetçik et al., 2008);

♠ a choleretic effect (Gebhardt, 2001; Saénz Rodriguez et al., 2002) attributed to metabolites of caffeoylquinic acids (Wittemer et al., 2005);

♥ acting as lipid-lowering agents (Gebhardt, 1997).

Globe Artichoke Ameliorates Diabetes

Many general dieting rules help in reducing blood sugar levels but there some specific individual foods that have been found to be particularly useful. One in particular is the globe artichoke. This is found growing around the Mediterranean and the Canary Islands. 

A small study examined the effect of consuming boiled artichoke at a meal reduced blood sugar and insulin levels after 30 minutes after they were eaten. The researchers were not clear how the artichoke extract might reduce blood sugar levels. However it was evident that healthy adults and those with metabolic syndrome did not benefit as greatly (Nomikos et al., 2007). 

Then there were rat studies which highlighted the role that artichoke extracts could play in ameliorating the affects of diabetes. There is a blood sugar lowering study using a rat model to thank for this observation (Fantini et al., 2011).

In humans one study in 39 overweight adults found consuming a kidney bean and artichoke leaf extract daily for over 2 months lowered the fasting blood sugar levels when compared to not supplementing. Some of the benefits were probably due to the kidney bean and not just the globe artichoke (Rondanelli et al., 2011).

At the biochemical level it is thought that artichoke extract slows down the activity of alpha-glucosidase. This enzyme breaks down starch into glucose which impacts on blood sugar.

Nexira offer a spray-dried extract containing 5% cynarin based on water extracts of the raw leaves.

Arty Water

We  also know of a product called Arty™ water which is available in the USA and is produced out of Irvine, California. The product has versatility being served hot or cold and as a mixer for cocktails. To quote the supplier’s description of the health benefits for the product:- “ARTY™ Water is a multi-functional, plant-based beverage containing antioxidants, electrolytes, Vitamins A, E, C, B1, B2, B3, B6, and B9 and vital minerals Sodium, Potassium, Calcium and Iron.

The combination of nutrients found in ARTY™ Water may help reduce increased levels of oxidative stress biomarkers after exercise. Artichoke-derived bioflavonoids are known for their excellent anti-inflammatory properties and can reduce joint pain and muscle soreness.” and:- “Targeted for daily hydration and replenishment of nutrients, ARTY™ Water is vegan, low-glycemic, lactose-free, gluten-free and cholesterol-free. No added colorant, flavoring agent, or caffeine is contained in ARTY™ Water. Just the good stuff!” The product is being shown at various food expos around the USA.

1st revision 24/01/15 2nd revision 19/11/19

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