The antioxidant and enzyme inhibitory properties of methanolic extracts from four aromatic plants used in traditional medicine and food [ (L.) Savi subsp. , subsp. Franco, L. and subsp. (Hoffmanns. & Link) Bonnier & Layens] were evaluated. The extract from exhibited the strongest DPPH (IC of 4.65 ± 0.12 µg/ml) and ABTS (1479.56 ± 12.29 µmol/g) scavenging capacities, as well as the largest ferric reducing ability (1746.76 ± 45.11 µmol/g). This extract also showed the highest total phenolic content (1597.20 ± 24.10 µmol/g) and although HPLC-DAD analysis revealed rosmarinic acid as the main compound of the extract, other compounds seem to be involved in the antioxidant activity. Furthermore, the extract from , which was found to be rich in caffeoylquinic and dicaffeoylquinic acids and in pinocembrin, showed the highest inhibitory potential against acetylcholinesterase, tyrosinase and α-glucosidase. Overall, the results obtained validate the usefulness of the studied plants as valuable sources of natural agents beneficial for human health.

The recent interest in wild edible plants is associated to their health benefits, which are mainly due to their richness in antioxidant compounds, particularly phenolics. Nevertheless, some of these compounds are metabolized after ingestion, being transformed into metabolites frequently with lower antioxidant activity. The aim of the present study was to evaluate the influence of the digestive process on the total phenolic contents and antioxidant activity of extracts from four wild edible plants used in the Mediterranean diet (Beta maritima L., Plantago major L., Oxalis pes-caprae L. and Scolymus hispanicus L.). HPLC-DAD analysis revealed that S. hispanicus is characterized by the presence of caffeoylquinic acids, dicaffeoylquinic acids and flavonol derivatives, P. major by high amounts of verbascoside, B. maritima possesses 2,4-dihydroxybenzoic acid, 5-O-caffeoylquinic acid, quercetin derivatives and kaempferol-3-O-rutinoside and O. pes-caprae extract contains hydroxycinnamic acids and flavone derivatives. Total phenolic contents were determined by Folin-Ciocalteu assay, and antioxidant activity by the ABTS, DPPH, ORAC and FRAP assays. Phenolic contents of P. major and S. hispanicus extracts were not affected by digestion, but they significantly decreased in B. maritima after both phases of digestion process and in O. pes-caprae after the gastric phase. The antioxidant activity results varied with the extract and the method used to evaluate the activity. Results showed that P. major extract has the highest total phenolic contents and antioxidant activity, with considerable values even after digestion, reinforcing the health benefits of this species.

In this work we evaluated methanolic extracts from different parts (leaves, seeds, fruit peel and pulp) of L. for antioxidant activity and the ability to inhibit enzymes linked with neurodegenerative diseases: acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase (TYR). The total content of phenolics, flavonoids and condensed tannins was also determined. The antioxidant and inhibitory activities of the extracts varied significantly according to the tissue. Seed extracts showed the greatest ability to scavenge DPPH (IC = 81.28 µg mL) and ABTS (1440.42 µmol [Formula: see text]) and to reduce iron (1142.46 µmol [Formula: see text]). Seed and peel extracts strongly inhibited AChE (IC = 660.16 and 653.68 µg mL, respectively) and BChE (IC = 304.86 and 701.54 µg mL, respectively). The strongest inhibition of TYR was achieved by the seed and pulp extracts (268.97 and 279.99 µg mL, respectively). The highest levels of phenolics and condensed tannins were found in the seed extract (1564.88 µmol [Formula: see text] and 170.00 µmolc [Formula: see text], respectively) whereas the leaf extract was the richest in flavonoids (139.88 µmol [Formula: see text]). HPLC-DAD analysis indicated the presence of flavonoids and phenolic acids (hydroxycinnamic acids) in the leaf and pulp extracts. A high correlation was found between the total condensed tannins content and the antioxidant and enzyme inhibition activities, suggesting these compounds are responsible for the biological activity of the extracts. Overall, our results indicate that extracts may provide a new and alternative source of agents for medical and industrial applications.