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 mu g/mL) and anti-inflammatory (IC50 = 148 mu g/mL) activities, and capacity to inhibit the formation of thiobarbituric acid reactive substances (TBARS) (IC50 = 5 mu g/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.