Context: Ostrich (Struthio camelus ) egg possesses a high amount of food proteins and thus plays an important role in nutrition. Objective: Ostrich egg white proteins were hydrolyzed with pepsin and pancreatin to examine its antioxidant properties and further characterized the most active peptide. Materials and methods : Ostrich egg white protein hydrolysate (OEWPH) was fractionized using reversed phase high-pressure liquid chromatography (HPLC). The antioxidant activity of OEWPH and its HPLC fraction were investigated based on their scavenging capacity1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,20 -azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), superoxide (O.-2 ), hydroxyl (OH.-) radicals, and Cu +2 chelating. In a wound healing assay, paravertebral excision (1cm diameter) was made on the skin and the percentage of wound closure was measured at defined intervals (0, 3, 7, and 14d). Results: A potent antioxidant peptide named DG-10 with the sequence DAESLSRLLG (MW: 1060.18±0.5Da) was identified from OEWPH. The peptide DG-10 showed DPPH (IC50 ¼ 0.0085mg/ml), ABTS  + (IC50 ¼ 0.56mg/ml), superoxide (IC50 ¼ 0.36mg/ml), and hydroxyl (IC50 ¼ 0.4mg/ml) radical scavenger and copper chelating activity (IC 50 ¼ 0.28mg/ml). In vitro cultured HFLF-pI 5, the cell model, also revealed that DG-10 could protect HFLF-pI 5 cells against H 2O2 -treated necrosis. Ointment composed of DG-10 peptide exhibited wound-healing properties on adult rats (Wistar strain). The percentage of wound closure in peptide-treated group was 98% by day 14.Discussion and conclusion: Our results suggested that DG-10 is a natural agent obtained from ostrich egg possessing considerable antioxidant and wound-healing properties.

Keywords