Phenolic profile and bioactive potential of cardoon (Cynara cardunculus L.) inflorescences: selection of the best genotype for food application

Cynara cardunculus L. (syn. cardoon) belongs to the Asteraceae family and is native to the Mediterranean basin. This species is widely used for milk coagulation of PDO cheeses and consumed due to its rich nutritional value and related medicinal properties (e.g. choleretic, cardiotonic, antidiabetic, liver disease treatment). In the last decade, the interest in this crop increases due to its multifaceted industrial applications. It has been explored for animal feed and lightwood panels, biodiesel, paper pulp, and food oil production. Their production countries estimate a generation of approximatly 15 to 30 t/ha of dry biomass. The adequate exploitation and characterization of the species are essential for circular economic stimulation and environmental impact reduction. The hydroethanolic extracts of four cardoon genotypes and their vegetable tissues (stigma, corolla, bracts, pappus, receptacle) were studied. The polyphenolic profile was analyzed by HPLC-DAD-ESI/MS. The antioxidant activity was evaluated TBARS and OxHLIA cell-based assays.The anti-inflammatory activity was assessed through the extracts’ capacity to inhibit the pro-inflammatory mediator nitric oxide. Finally, the cytotoxic potential was evaluated against four tumor and a non-tumor cell line (PLP2) using the sulforhodamine B assay. Fourteen phenolic compounds were tentatively identified. The corolla presented the higher variety and bracts the higher content of phenolic compounds. In terms of bioactivity, none of the tested extracts exhibit anti-inflammatory potential. Genotype F1-1-1 exhibits a higher cytotoxic potential. All the four genotypes and vegetable tissues tested exhibited antioxidant capacity, especially corolla of F4-1-4 genotype for TBARS assay (IC50 = 38 μg/mL) and its receptacle for OxHLIA (IC50 = 71 μg/mL). In conclusion, this study showed that the phenolic composition and biological activities of cardoon are influenced by both genotype and plant tissue. Further studies are needed to determine the genetic information for obtaining the highest bioactivity.To the Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2021); PhD grant of Filipa Mandim (SFRH/146614/2019) and J. Pinela (CEECIND/01011/2018), M.I. Dias and L. Barros contracts.