Purification and Identification of Antioxidant Peptides from Enzymatic Hydrolysate of Spirulina platensis

Abstract

The aim of this study was to isolate antioxidant peptides from an enzymatic hydrolysate of Spirulina platensis. A novel antioxidant peptide was obtained by ultrafiltration, gel filtration chromatography, and reverse-phase high-performance liquid chromatography, with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay used to measure the antioxidant activity, and the sequence was determined to be Pro-Asn-Asn (343.15 Da) by electrospray ionization tandem mass spectrometry. This peptide was synthesized to confirm its antioxidant properties, and it exhibited 81.44 ± 0.43% DPPH scavenging activity at 100 µg/ml, which was similar to that of glutathione (82.63 ± 0.56%). Furthermore, the superoxide anion and hydroxyl free-radical scavenging activities and the SOD activity of the peptide were 47.84 ± 0.49%, 54.01 ± 0.82%, and 12.55 ± 0.75%, respectively, at 10 mg/ml. These results indicate that S. platensis is a good source of antioxidant peptides, and that its hydrolysate may have important applications in the pharmaceutical and food industries.

Angiotensin-I-Converting Enzyme Inhibitory and Antioxidant Activity of Tryptic Spirulina Platensis Protein Hydrolysates: Effect of Hydrolysis and in Vitro Gastrointestinal Digestion

“…However, further digestion in the intestine brought the ACE inhibitory activity of the final GI digests to 24.85±1.01-33.60±2.40 (p<0.05), indicating that some peptides with stronger ACE inhibitory activities were produced during the simulated GI digestion. Previous studies have also reported that peptides derived from rapeseed [16], egg white lysozyme [62], and ham [64] still exhibited ACE inhibitory activity after GI digestion.…”

“…Enzymatic hydrolysis enables the release of these peptides which are inactive within the sequence of parent protein [14 and 15]. It has been suggested that non-protein compounds such as phenolics and pigments need to be taken into account when evaluating the antioxidant activities of some protein hydrolysates like rapeseed [16]. S. platensis contains phycobiliproteins as lightharvesting protein-pigment complexes [17].…”

Antioxidant Activity of Purified Active Peptide Derived from Spirulina platensis Enzymatic Hydrolysates

“…Generally, the scavenging activity of ultrafiltrated hydrolysates was significantly higher than without ultrafiltration or hydrolysis, which was indicated by the improvement of oxidation resistance compound by enzymatic hydrolysis (Yu et al, 2016). Therefore, the purified S. platensis protein in this study was directly digested by several proteolytic enzymes and filtrated to molecular weight cut off < 3 kDa.…”

“…DPPH-free radical scavenging activity was measured according to the method described by Yu et al (2016) with some modification.…”

“…It is generally cultured in Asia, Africa, South America and usually grows almost all the year (FerreiraHermosillo et al, 2011). It contains 60-70% of proteins by weight and exhibits a wide range of biological properties, including antioxidant activity (Yu et al, 2016). In this study, the active peptide derived from S. platensis was isolated and examined its bioactivity as free-radical inhibitor using DPPH (2.2-Diphenyl-1-picrylhydrazyl) assay.…”