An Overview of the Versatility of the Parts of the Globe Artichoke (Cynara scolymus L.), Its By-Products and Dietary Supplements

Cynara scolymus, also known as the globe artichoke or artichoke, is grown as a food, mainly in the Mediterranean, Canary Islands, and Egypt, as well as in Asia and South America. It has also been associated with various health benefits and is used in plant-based dietary supplements and herbal infusions. Its edible parts, consisting of the head or capitula, flower, and leaves, have shown various biological activities, including anti-cancer, hepatoprotective and antimicrobial potential. The leaves are mainly used in infusions and extracts for their health-promoting properties, although all their edible parts may also be consumed as fresh, frozen, or canned foods. However, its primary health-promoting activity is associated with its antioxidant potential, which has been linked to its chemical composition, particularly its phenolic compounds (representing 96 mg of gallic acid equivalent per 100 g of raw plant material) and dietary fiber. The main phenolic compounds in the heads and leaves are caffeic acid derivatives, while the flavonoids luteolin and apigenin (both present as glucosides and rutinosides) have also been identified. In addition, heat-treated artichokes (i.e., boiled, steamed or fried), their extracts, and waste from artichoke processing also have antioxidant activity. The present paper reviews the current literature concerning the biological properties of different parts of C. scolymus, its by-products and dietary supplements, as well as their chemical content and toxicity. The literature was obtained by a search of PubMed/Medline, Google Scholar, Web of Knowledge, ScienceDirect, and Scopus, with extra papers being identified by manually reviewing the references.

The antioxidant activity of artichoke (Cynara scolymus): A systematic review and meta-analysis of animal studies

Current evidence has shown antioxidant activity of artichoke as a potent source of antioxidant compounds. However, it seems that the antioxidant activity of artichoke has not yet been reviewed. Therefore, the present study was designed to perform a systematic review of human studies, animal models, and in vitro systems and to conduct a meta-analysis of animal studies on the antioxidant effects of artichoke. We searched four electronic databases till April 2018 using relevant keywords. All English language articles were assessed. For animal studies, standardized mean difference was pooled using a random effects model. The included studies were evaluated for eligibility and risk of bias. Thirty-nine articles (two human, 23 animal, and 14 in vitro studies) were reviewed. The results of in vitro systems supported the antioxidant effect of artichoke, whereas limited clinical trials indicated no change or a slight improvement of antioxidant status. Finding of animal studies indicated that artichoke extract supplementation increased superoxide dismutase, catalase, glutathione, and glutathione peroxidase level in liver, as well as, decreased malondialdehyde level in liver and plasma of animals with induced disease significantly compared with comparison group. This meta-analysis provided convincing evidence for antioxidant activity of artichoke in animals.

The creation and physiological relevance of divergent hydroxylation patterns in the flavonoid pathway

Flavonoids and biochemically-related chalcones are important secondary metabolites, which are ubiquitously present in plants and therefore also in human food. They fulfill a broad range of physiological functions in planta and there are numerous reports about their physiological relevance for humans. Flavonoids have in common a basic C(6)-C(3)-C(6) skeleton structure consisting of two aromatic rings (A and B) and a heterocyclic ring (C) containing one oxygen atom, whereas chalcones, as the intermediates in the formation of flavonoids, have not yet established the heterocyclic C-ring. Flavonoids are grouped into eight different classes, according to the oxidative status of the C-ring. The large number of divergent chalcones and flavonoid structures is from the extensive modification of the basic molecules. The hydroxylation pattern influences physiological properties such as light absorption and antioxidative activity, which is the base for many beneficial health effects of flavonoids. In some cases antiinfective properties are also effected.

An ex vivo methodology to assess the lipid peroxidation in stratum corneum

Environmental risks, particularly UV radiation, provide a challenge to the function of the skin barrier. Protective measures such as the use of antioxidant products represent a possible method of providing protection to the skin. This paper reports the development of a non-invasive ex vivo method using tape strips of the outermost layers of stratum corneum (SC) from human volunteers in order to determine the effectiveness of an antioxidant emulsion topically applied to prevent lipid peroxidation (LPO) in the horny layer after an UV irradiation exposure. Two different formulations were used: formulation (A), containing Vitamin A, E and C, and formulation (B) containing fish extract. Both formulations were topically applied in vivo on volunteer forearms; then, a tape stripping of the SC of each volunteer was carried out. The lipid peroxidation was measured ex vivo after an UV irradiation of the SC samples. The amount of SC stripped to evaluate differences in lipid peroxidation, the UV irradiation intensity to form lipid peroxides and the accuracy of lipid peroxide analysis were optimized in this methodology using formulation (A). After an exposure application of seven days, a group of three strips of the outermost layers of SC of volunteers was irradiated with an intensity of 182.7 J/cm(2) to quantify the LPO inhibition. The percentage of LPO inhibition obtained after topical application of both formulations was in the range of 40-58% demonstrating the effectiveness of the formulations topically applied against lipid peroxidation on human SC. This methodology may be used as a quality control tool to determine ex vivo the percentage of the LPO inhibition on human SC for a variety of antioxidants topically applied.