Abstract:Based on the combination of repeated freeze-thaw cycles, homogenization, and ultrasonic-extraction, the extraction rate between salt-extraction and water-extraction of Spirulina proteins was compared. Taking water-extracted Spirulina proteins as the raw material, six types of Spirulina proteolytic peptides were obtained through enzymolysis of Spirulina proteins using trypsin, chymotrypsin, pepsin, alkaline protease, and papain individually, using alkaline protease and papain together, and using trypsin, pepsin, and chymotrypsin to simulate the digestive processes of the gastrointestinal tract in vitro. Results of the degree of hydrolysis and anti-proliferation effects before and after decolorization suggested that there was no direct correlation between the degree of hydrolysis and the anti-proliferation effects. In addition, decolorization was found to lower the anti-tumor activity of hydrolytic components. Therefore, five types of proteolytic peptides with good anti-proliferation effects were used for ultrafiltration, providing nine components that could significantly inhibit the growth of both MCF-7 and HepG-2 in vitro. Then, the 0~3 K component of alkaline protease was isolated and purified using a Sephadex G-15 column to obtain the A3 component, which had a strong anti-proliferation effect on MCF-7 and HepG-2 cells, showing IC50 values of 64.59 μg/mL and 61.65 μg/mL, respectively. Additionally, another three components, A1, A4, and A5, were obtained, which had strong selective anti-proliferation effects on HepG-2 cells, with IC50 values of 47.67 μg/mL, 79.44 μg/mL, and 69.54 μg/mL, respectively. These results provide a theoretical basis for the development of new drugs and health foods using Spirulina platensis as raw materials.
