Phenolic profile (HPLC-UV) analysis and biological activities of two organic extracts from Echinops spinosissimus Turra roots growing in Tunisia

Echinops spinosissimus Turra subsp. roots was investigated, after extraction with two different solvents: ethanol and ethyl acetate, for its phenolic profile as well as biological activities. Echinops spinosissimus Turra subsp. spinosus roots ethanolic extract was characterized by the highest content of total polyphenols (19.3 mg GAE/100 g of DW). In addition, the phenolic profiles of the two studied extracts were analysed using HPLC-UV, where p-coumaric (8.59 mg/kg of DW) and cinnamic acids (4.68 mg/kg of DW) were detected as the most abundant phenolic acids, and kaempferol was the predominant flavonoids (30.37 mg/kg of DM) followed by quercetin and rutin in the ethanolic extract. While, only p-coumaric acid, epicatechin, kaempferol and quercetin were identified and quantified in ethyl acetate roots extract. All tested extracts exhibited an antimicrobial effect against Gram-positive and Gram-negative bacteria. These findings indicate that Echinops spinosissimus Turra subsp. spinosus roots can be regarded as a new source of edible oil having health benefits and nutritional properties.