Evaluation of Antioxidant and Wound-Healing Properties of EHO-85, a Novel Multifunctional Amorphous Hydrogel Containing <i>Olea europaea</i> Leaf Extract

The excess of free radicals in the wound environment contributes to its stagnation during the inflammatory phase, favoring hard-to-heal wounds. Oxidative stress negatively affects cells and the extracellular matrix, hindering the healing process. In this study, we evaluated the antioxidant and wound-healing properties of a novel multifunctional amorphous hydrogel-containing Olea europaea leaf extract (OELE). Five assessments were performed: (i) phenolic compounds characterization in OELE; (ii) absolute antioxidant activity determination in OELE and hydrogel (EHO-85); (iii) antioxidant activity measurement of OELE and (iv) its protective effect on cell viability on human dermal fibroblasts (HDFs) and keratinocytes (HaCaT); and (v) EHO-85 wound-healing-capacity analysis on diabetic mice (db/db; BKS.Cg-m+/+Leprdb). The antioxidant activity of OELE was prominent: 2220, 1558, and 1969 µmol TE/g by DPPH, ABTS, and FRAP assays, respectively. Oxidative stress induced with H2O2 in HDFs and HaCaT was normalized, and their viability increased with OELE co-treatment, thus evidencing a protective role. EHO-85 produced an early and sustained wound-healing stimulating effect superior to controls in diabetic mice. This novel amorphous hydrogel presents an important ROS scavenger capacity due to the high phenolic content of OELE, which protects skin cells from oxidative stress and contributes to the physiological process of wound healing