Purification and anti-inflammatory effect of selenium-containing protein fraction from selenium-enriched Spirulina platensis

Spirulina platensis is an excellent carrier of Se, and thus widely used in medical fields and as well as in the food industry. However, there is little information about the characteristics and bioactivity of selenium-containing S. platensis proteins (Se-SP). In this study, Se-SP with different molecular weights were isolated from selenium-enriched S. platensis , and the bioactivities (such as antioxidant and anti-inflammatory activities) of Se-SP were investigated. Se-SP3 (with a molecular weight range of 20–48 kDa) showed better free radical scavenging ability (ABTS) than the other Se-SPs. In addition, Se-SP3 suppressed inflammatory cytokines, in which decreased by 74% interleukin 6 (IL-6), 42.28% tumor necrosis factor-α (TNF-α), 69.07% content of malondialdehyde (MDA), 40.45% interleukin-1β (IL-1β) relative to the LPS group. Moreover, Se-SP3 decreased the nitric oxide (NO) production by 64.84% compared with the LPS group and increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), indicating that Se-SP3 has excellent antioxidant and anti-inflammatory activities, and could be used as a functional food ingredient or natural medicine. • Spirulina platensis is an excellent carrier of Se. • The characteristics and bioactivity of Se-SP with different molecular weights were investigated. • Protein Se-SP3 showed the better antioxidant and anti-inflammatory activity.