An identified antioxidant peptide obtained from ostrich (Struthio camelus) egg white protein hydrolysate shows wound healing properties

Abstract

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, 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), superoxide ([Formula: see text]), hydroxyl (OH(•-)) radicals, and Cu(+2) chelating. In a wound healing assay, paravertebral excision (1 cm diameter) was made on the skin and the percentage of wound closure was measured at defined intervals (0, 3, 7, and 14 d).

Results: A potent antioxidant peptide named DG-10 with the sequence DAESLSRLLG (MW: 1060.18 ± 0.5 Da) was identified from OEWPH. The peptide DG-10 showed DPPH (IC50 = 0.0085 mg/ml), ABTS(•+) (IC50 = 0.56 mg/ml), superoxide (IC50 = 0.36 mg/ml), and hydroxyl (IC50 = 0.4 mg/ml) radical scavenger and copper chelating activity (IC50 = 0.28 mg/ml). In vitro cultured HFLF-pI 5, the cell model, also revealed that DG-10 could protect HFLF-pI 5 cells against H2O2-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: Bioactive peptide; HFLF-PI 5 cell line; HPLC.