New Insight into Enzyme Inhibitory and Anti-proliferative Activity of Echinops ritro L. (Asteraceae)

Echinops ritro L. is a perennial herbaceous plant in the tribe Cardueae, Asteraceae family, widely distributed, up to 1000 m a.s.l. In the present study, the enzyme inhibitory and anti-proliferative activity of E. ritro leaves and flowering heads extracts were assayed. Quantitative determination of 22 analytes, including eleven acylquinic and one hydroxycinnamic acids, and ten flavonoids was performed by Ultra high-performance liquid chromatography – diode array detector (UHPLC-DAD) analyses. The major compound was 1,5-dicaffeoylquinic acid, being presented at $$20.48\pm 0.22$$ µg/mg in the flowering heads, while the leaves demonstrated very high levels of chlorogenic acid ($$117.29\pm 14.20$$ µg/mg) and 3,5-dicaffeoylquinic acid ($$12.79\pm 0.282$$ µg/mg). The flavonoids were dominated by isoquercitrin and rutin ($$3.13\pm 0.033$$ and $$3.25\pm 0.057$$ µg/mg, respectively) together with metoxylated aglycones nepetin, hispidulin and jaceosidin (up to 0.51 µg/mg). The leaves extract revealed prominent acetylcholinesterase ($$2.33\pm 0.09$$ mg GALAE/g) and α-glucosidase inhibitory potential ($$0.37\pm 0.01$$ mmol ACAE/g). Nevertheless, the flowering heads extract showed distinct butyrylcholinesterase ($$1.41\pm0.35$$ mg GALAE/g), tyrosinase ($$45.66\pm0.84$$ mg KAE/g), amylase ($$0.37\pm0.02$$ mmol ACAE/g), and lipase ($$9.06\pm1.43$$ mg OE/g) inhibitory activity. The anti-proliferative assay was completed towards THP-1 monocyte leukemic cells, where at a concentration $$>1000$$ µg/mL, a significant dose dependent reduction of cell viability was observed for the leaves extract. In conclusion, the data revealed a new insight into the taxon for its health benefit application.