New Insights on Euphorbia dendroides L. (Euphorbiaceae): Polyphenol Profile and Biological Properties of Hydroalcoholic Extracts from Aerial Parts

Abstract

Euphorbia dendroides L. is a rounded shrub commonly found in the Mediterranean area well-known, since ancient times, for its traditional use. The aim of the present study was to investigate the phytochemical profile as well as the antioxidant and anti-inflammatory properties of flower (FE), leaf (LE), fruit (FrE), and branch (BE) hydroalcoholic extracts. For this purpose, a preliminary phytochemical screening followed by RP-LC-DAD-ESI-MS analysis, as well as several in vitro cell-free colorimetric assays, were carried out. Moreover, the toxicity of the extracts was investigated by the brine shrimp lethality assay. All extracts showed a high content of polyphenols, in particular phenolic acids (chlorogenic acid 0.74-13.80 g/100 g) and flavonoids (rutin 0.05-2.76 g/100 g and isovitexin 8.02 in BE). All the extracts showed strong and concentration-dependent antioxidant and anti-inflammatory activity with, on average, the following order of potency: FE, LE, FrE, and BE. Interestingly, all the extracts investigated did not show any toxicity on Artemia salina. Moreover, the only LD₅₀ found (BE, 8.82 mg/mL) is well above the concentration range, which has been shown the biological properties. Considering this, this study offers the first evidence of the possible use of the polyphenol extracts from the aerial parts of E. dendroides as promising antioxidant and anti-inflammatory agents.

Keywords: Euphorbia dendroides L.; aerial parts; anti-inflammatory activity; antioxidant activity; polyphenols; toxicity.

Figure 1

Euphorbia dendroides L. (a) and particular of the aerial parts (b). Original photo by SR.

Figure 2

Representative LC-DAD chromatograms of E. dendroides flower (FE), leaf (LE), fruit (FrE), and branch (BE) extracts acquired at 260 nm. Peak numbers refer to compounds listed in Table 2.

Figure 3

The antioxidant and free radical-scavenging activity of E. dendroides flower (FE), leaf (LE), fruit (FrE), and branch (BE) extracts towards ORAC (a); TEAC (b); Iron chelating-activity (c); FRAP (d); DPPH (e) and β-carotene bleaching (f) assay. Results were expressed as the mean inhibition percentage (%) ± standard deviation of three independent experiments (n = 3).

Figure 4

The anti-inflammatory activity of E. dendroides flower (FE), leaf (LE), fruit (FrE) and branch (BE) extracts towards BSA denaturation assay (a) and protease inhibition assay (b). Results were expressed as the mean inhibition percentage (%) ± standard deviation of three independent experiments (n = 3). * p < 0.001 vs. FE; ^§ p < 0.001 vs. LE; ^# p < 0.001 vs. FrE; ^& p < 0.05; ^° p < 0.05 vs. LE; ^Ψ p < 0.05 vs. FrE.