Chemical composition and in vitro biological activities of cardoon (Cynara cardunculus L. var. altilis DC.) seeds as influenced by viability

Insights into the phenolic composition and in vitro bioactivity of cardoon capitulum: A nutraceutical-oriented valorization study

The capitulum constituents (stigma, corolla, bracts, pappus, and receptacle) of seven cardoon cultivars were studied for their polyphenolic composition and bioactive properties. Fifteen phenolic compounds were identified, secoiridoid, secoxyloganin, and apigenin-O-hexuronoside in higher concentrations. The bracts had the highest concentration of phenolic compounds, and the corolla had the greatest variety. The corolla of F4-1-4 and F1-34-1 cultivars, and bracts of F1-1-1, F1-19-4, and F4-37-1 cultivars revealed the greatest capacity to inhibit the thiobarbituric acid reactive substances formation (IC50 of 38 and 40.4 µg/mL, respectively). The corolla of F1-34-1 cultivar showed higher antihaemolytic activity than the positive control Trolox (IC50 5.5 vs. 20 µg/mL). Bracts of the F4-25-2 cultivar showed higher cytotoxic activity. No hepatotoxicity or anti-inflammatory effects were presented by the studied samples. These bioactivities exhibit a significative correlation with phenolic compounds, in particular flavonoids. Antimicrobial capacity was also observed, with all samples presenting higher antifungal potential than positive controls.

The wide spectrum of industrial applications for cultivated cardoon (Cynara cardunculus L. var. Altilis DC.): A review

Cynara cardunculus L. var. altilis DC. belongs to the Asteraceae family and is widely used. This species is integrated into the Mediterranean diet and has broad applicability due to its rich chemical composition. Its flowers, used as a vegetable coagulant for gourmet cheese production, are rich in aspartic proteases. Leaves are rich in sesquiterpene lactones, the most abundant being cynaropicrin, while stems present a higher abundance of hydroxycinnamic acids. Both classes of compounds exhibit a wide range of bioactive properties. Its chemical composition makes it applicable in other industrial sectors, such as energy (e.g., manufacturing of biodiesel and biofuel) or paper pulp production, among other biotechnological applications. In the last decade, cardoon has been identified as a competitive energy crop, constituting an opportunity for the economic recovery and development of the rural areas of the Mediterranean basin. This article reviews the chemical composition, bioactive properties, and multifaceted industrial applications of cardoon.

Valorization of Punica granatum L. Leaves Extracts as a Source of Bioactive Molecules

Due to a lack of innovative valorization strategies, pomegranate processing generates a significant amount of residues with a negative environmental footprint. These by-products are a rich source of bioactive compounds with functional and medicinal benefits. This study reports the valorization of pomegranate leaves as a source of bioactive ingredients using maceration, ultrasound, and microwave-assisted extraction techniques. The phenolic composition of the leaf extracts was analyzed using an HPLC-DAD-ESI/MSn system. The extracts’ antioxidant, antimicrobial, cytotoxic, anti-inflammatory, and skin-beneficial properties were determined using validated in vitro methodologies. The results showed that gallic acid, (-)-epicatechin, and granatin B were the most abundant compounds in the three hydroethanolic extracts (between 0.95 and 1.45, 0.7 and 2.4, and 0.133 and 3.0 mg/g, respectively). The leaf extracts revealed broad-spectrum antimicrobial effects against clinical and food pathogens. They also presented antioxidant potential and cytotoxic effects against all tested cancer cell lines. In addition, tyrosinase activity was also verified. The tested concentrations (50–400 µg/mL) ensured a cellular viability higher than 70% in both keratinocyte and fibroblast skin cell lines. The obtained results indicate that the pomegranate leaves could be used as a low-cost source of value-added functional ingredients for potential nutraceutical and cosmeceutical applications.

Upgrading cardoon biomass into Polyhydroxybutyrate based blends: A holistic approach for the synthesis of biopolymers and additives

Cardoon, Cynara cardunculus L. represents a biorefinery crop with a great potential in the bioplastic field. This work investigates the valorization of different cardoon components into high added value products, finally recombined into novel upgraded bioplastics. Bioprocesses for Polyhydroxybutyrate (PHB) and medium-chain-length Polyhydroxyalkanoates (mcl-PHA) production were set up starting from root inulin and seed oil respectively, highlighting the effect of process conditions on polymer properties. The ternary blend, in which the PHB polymer matrix was added with mcl-PHA and epoxidized cardoon oil, evidenced a synergic effect of both additives in modulating PHB structural and thermal properties, promoted by the physical interaction occurring among the components. This proof-of concept frames the paper in the holistic approach of circular economy applied to bioplastic production.

Phenolic Composition and Antioxidant, Anti-Inflammatory, Cytotoxic, and Antimicrobial Activities of Cardoon Blades at Different Growth Stages

Simple Summary

The rapid increase of the world population has promoted a more sustainable and efficient use of natural resources. To achieve complete and proper upcycling of plant crops, it is important to know their potential for industrial exploitation. Cardoon (Cynara cardunculus L.) is a species native to the Mediterranean basin widely used in different sectors, including food and pharmaceuticals. Despite their multiple industrial applications, not all plant tissues have been incorporated into the value chain. Therefore, this work aimed to characterize the phenolic composition and bioactive properties of cardoon blades throughout the phenological growth cycle. In addition to the structural variety of phytochemicals detected in the blade extracts, their antioxidant, anti-inflammatory, anti-proliferative, and antimicrobial properties were also highlighted. While immature material showed higher levels of phenolic compounds and greater potential to inhibit lipid peroxidation, samples at higher development stages had greater anti-proliferative, anti-inflammatory, and antimicrobial potential. These results demonstrate that the growth cycle influences the bioactive potential of cardoon blades and will be useful to establish suitable industrial applications, such as the development of ingredients for functional foods and nutraceuticals, among other products.

Abstract

Cardoon (Cynara cardunculus var. altilis) blades were collected at sixteen sampling dates (B1–B16) to study the influence of the phenological growth stage on the phenolic composition and biological properties. Twenty phenolic compounds were identified, among which trans 3,4-O-dicaffeoylquinic acid, 5-O-caffeoylquinic acid, and luteolin-O-hexoside (39.6, 42.6, and 101.0 mg/g extract, respectively) were the main compounds. Immature blades (B3) had a higher content of phenolic compounds (178 mg/g extract) and a greater ability to inhibit the formation of thiobarbituric acid reactive substances (IC₅₀ of 1.61 µg/mL). Samples at more advanced growth stages revealed a greater capacity to inhibit oxidative hemolysis (B8, IC₅₀ of 25 and 47.4 µg/mL for Δt of 60 and 120 min, respectively) and higher cytotoxic (B8–B13, GI₅₀ between 7.1 and 17 µg/mL), anti-inflammatory (B13, IC₅₀ of 10 µg/mL), and antibacterial activities. In turn, the antifungal activity varied depending on the tested fungi. All these results suggest that maturity influences the phenolic composition and bioactive properties of cardoon blades, which reveal great potential for the development of bioactive ingredients for food and pharmaceutical applications, among others.

Chemical composition and biological activity of cardoon (Cynara cardunculus L. var. altilis) seeds harvested at different maturity stages

Cardoon seeds collected in Greece at four different maturity stages (samples S1 to S4) were analysed in terms of chemical composition and in vitro bioactivities. The content of phenolic compounds (six compounds in total) increased with increasing maturity, and 3,5-O-dicaffeyolquinic (14.8-33.8 mg/g extract) acid was the compound detected in higher abundance. Mature seeds (sample S4) also revealed the highest content in lipids (23 g/100 g extract) and tocopherols (29.62 mg/100 g dw) and demonstrated the highest cytotoxic (GI₅₀ of 97-216 µg/mL) and anti-inflammatory (IC₅₀ = 148 µg/mL) activities, and capacity to inhibit the formation of thiobarbituric acid reactive substances (TBARS) (IC₅₀ = 5 µg/mL). Cardoon seed hydroethanolic extracts also revealed high antibacterial and antifungal potential, particularly samples S3 and S1, respectively. This study proved the multifaceted potential associated with valorisation of cardoon seeds, while their biological and chemical composition can be influenced by the maturity stage.

Bioactive Compounds from Cardoon as Health Promoters in Metabolic Disorders

Cardoon (Cynara cardunculus L.) is a Mediterranean plant and member of the Asteraceae family that includes three botanical taxa, the wild perennial cardoon (C. cardunculus L. var. sylvestris (Lamk) Fiori), globe artichoke (C. cardunculus L. var. scolymus L. Fiori), and domesticated cardoon (C. cardunculus L. var. altilis DC.). Cardoon has been widely used in the Mediterranean diet and folk medicine since ancient times. Today, cardoon is recognized as a plant with great industrial potential and is considered as a functional food, with important nutritional value, being an interesting source of bioactive compounds, such as phenolics, minerals, inulin, fiber, and sesquiterpene lactones. These bioactive compounds have been vastly described in the literature, exhibiting a wide range of beneficial effects, such as antimicrobial, anti-inflammatory, anticancer, antioxidant, lipid-lowering, cytotoxic, antidiabetic, antihemorrhoidal, cardiotonic, and choleretic activity. In this review, an overview of the cardoon nutritional and phytochemical composition, as well as its biological potential, is provided, highlighting the main therapeutic effects of the different parts of the cardoon plant on metabolic disorders, specifically associated with hepatoprotective, hypolipidemic, and antidiabetic activity.

Phenolic Composition and Biological Properties of Cynara cardunculus L. var. altilis Petioles: Influence of the Maturity Stage

Hydroethanolic extracts of cardoon petioles collected at sixteen growth stages (P1-P16) were characterized in terms of their phenolic composition and bioactive potential (antioxidant, cytotoxic, anti-inflammatory, and antimicrobial activities). Fifteen phenolic compounds were tentatively identified (i.e., ten phenolic acids and five flavonoid glycosides); the main compounds were 5-O-caffeoylquinic and 1,5-di-O-caffeoylquinic acids. Samples collected at early maturity (P1-P4) presented a weak positive correlation between the higher content in polyphenols (P3: 101-mg/g extract) and better inhibition capacity against thiobarbituric acid reactive substance formation (TBARS; P3: IC₅₀ = 5.0 µg/mL). Samples at intermediate maturation stages (P9) presented higher cytotoxic and anti-inflammatory potential. Moreover, immature petioles showed greater antihemolytic (OxHLIA; P4: IC₅₀ = 65 and 180 µg/mL for Δt of 60 and 120 min, respectively) and antibacterial activity. The antifungal activity varied depending on the maturation stage and the fungi strain. In conclusion, the maturation stage may greatly affect the polyphenols composition and content and the bioactive potential of cardoon petioles.

Chemical Characterisation-Biological Evaluation of Greek Cultivar Cardoon Seeds (Cynara cardunculus). A By-product with Potential High Added Value

Cynara cardunculus (artichoke) is a perennial plant of the Mediterranean basin, known since antiquity as food and for its therapeutic properties. Cynara is a relatively small genus with two cultivated species and one wild one. Recently, successful efforts have been made to cultivate wild cardoon and monetise it as a bioenergy crop. In this study, the seeds of an established Greek cultivar of C. cardunculus, cultivated in the experimental field and used as biofuel, have been researched for their chemical profile and nutritional value. According to the results, six lignans were isolated [arctigenin, arctiin, trachelogenin, tracheloside, cynarinine, and ethylate of trachelogenin (isolated for the first time from a natural source)] as well as the most characteristic metabolites of the genus (linoleic acid, trilinolein, and 3,5-dicaffeoylquinic acid). Moreover, the total phenolic content (31.18 - 54.51 mg gallic acid equivalents/g extract) and antioxidant and enzyme inhibitory activities of the seeds have been evaluated and showed strong antioxidant properties (44.42 - 516.81 mg gallic acid equivalents/g extract) as well as satisfactory bleaching (enzyme tyrosinase, 16.95 - 23.80 mg kojic acid equivalents/g extract), antidiabetic (enzymes a-amylase, a-glucosidase, 0.14 - 1.75 mmol acarbose equivalents/g extract), and protective against neurodegenerative disease (cholinesterase enzymes, 0.49 - 1.22 mg galanthamine equivalents/g extract) activities. The nutritional evaluation of the seeds confirmed them as a rich source of unsaturated fatty acids, dietary fibre (24.1%), and high protein content (19.3%). It is noteworthy that such a neglected bioactive by-product, with essentially high nutritional value, as the studied seeds could be investigated for its value-added applications towards food and food supplements areas.

Seasonal variation in bioactive properties and phenolic composition of cardoon (Cynara cardunculus var. altilis) bracts

Cardoon (Cynara cardunculus L.) bracts were collected at different maturation stages to investigate seasonal changes in the phenolic compounds profile and in vitro bioactivities. Among the 12 phenolic compounds tentatively identified, 3,5-O-dicaffeoylquinic acid (21.83 mg/g extract) and apigenin-7-O-glucuronide (10.6 mg/g extract) were the most abundant. Immature bracts (C1: principal growth stage (PGS) 5) had the highest phenolic compounds content, and anti-inflammatory (IC₅₀ = 72 µg/mL) and cytotoxic (GI₅₀ of 30-79 µg/mL) activities. Moreover, extract C1 inhibited efficiently the formation of thiobarbituric acid reactive substances (TBARS; IC₅₀ = 26.8 µg/mL), while extract C8 (PGS 8/9) was more effective against oxidative haemolysis (IC₅₀ 38 and 75 µg/mL). The highest antibacterial and antifungal activities were attributed to samples C1 and C6 (PGS 7/8) and samples C2 (PGS 5/6) and C4 (PGS 6/7), respectively. Overall, the obtained results suggest the seasonal changes of polyphenolic composition and bioactivity of cardoon bracts of variable maturity.