Propriétés antioxydantes et anti‑myéloperoxydase d’Aeonium arboreum: vers une protection contre le stress oxydatif et l’inflammation

Abstract

This study aims to quantify the content of phenolic compounds and flavonoids in the hydroethanolic extract of Aeonium arboreum leaves, and to evaluate its antioxidant capacity and its ability to inhibit myeloperoxidase activity. Colorimetric assays showed that the extract contains significant amounts of total polyphenols and flavonoids, with concentrations of 41.61 ± 4.418 µg EAG/mg of extract and 6.267 ± 0.527 µg EQ/mg of extract, respectively. The antioxidant activity of the extract was measured by assessing its ability to scavenge DPPH●, hydrogen peroxide (H2O2), and to reduce ferrous iron. The results showed that the extract exhibits a dose-dependent scavenging effect against DPPH● and H2O2, with IC50 values of 360,27 ± 42,68 µg/mL and 311.35 ± 18.11 µg/mL, respectively. Similarly, the extract also exhibited significant reducing activity, which was concentration-dependent, with an EC50 value of 145.69 µg/mL. On the other hand, pretreatment of enzymatic supernatants with different concentrations of the extract significantly (p<0,0001) inhibited myeloperoxidase activity, as assessed by the oxidation of 3,3′,5,5′-tetramethylbenzidine in the presence of H2O2. At 200 µg/mL, this inhibition reached 99.66%. It should be noted that at this concentration, the extract showed no significant effect on neutrophil viability as assessed by the trypan blue test. In conclusion, these results demonstrate that the hydroethanolic extract of Aeonium arboreum leaves possesses remarkable antioxidant and anti-myeloperoxidase properties, there by reinforcing its traditional use while opening up promising prospects for its exploitation as a source of natural antioxidants and anti-inflammatory agents. Keywords: Aeonium arboreum, antioxidants, flavonoids, myeloperoxidase, total polyphenols, oxidative stress.