Antioxidant and anticancer effects of functional peptides from ovotransferrin hydrolysates

BACKGROUND: Egg white is a good source for making functional peptides that can be used in the food industry. Ovotransferrin (OTF) is one of the major egg white proteins, with many functional properties, including antioxidant, antimicrobial and antiviral activities. However, enzymatic hydrolysis of ovotransferrin is known to further improve the functional activities of OTF. The aim of this study was to investigate the antioxidant and anticancer activities of functional peptides produced by two-step enzyme hydrolysis of OTF. RESULTS: OTF hydrolysates were prepared using promod 278P, thermolysin and a combination of the two enzymes. OTF and OTF hydrolysates showed strong antioxidant activities when analyzed using the DPPH assay. However, only OTF hydrolysates showed a strong free radical scavenging activity when NO- or ABTS-scavenging activity was measured. OTF hydrolysates showed stronger cytotoxic activities than the natural OTF against human cancer cell lines. Furthermore, OTF hydrolysates prepared with promod 278P + thermolysin combination showed the strongest cytotoxic activity, and their IC₅₀ values were 0.79, 0.78, 0.92 and 0.78 mg mL⁻¹ against AGS, LoVo, HT-29 and HeLa, respectively. CONCLUSION: These results indicated that the two-step enzyme hydrolysates of OTF have great potential for use as a food ingredient with antioxidant and anticancer activities.