Spirulina sp. LEB 18-extracted phycocyanin: Effects on liposomes’ physicochemical parameters and correlation with antiradical/antioxidant properties

[Display omitted] •Effects of Spirulina sp. LEB 18- extracted phycocyanin on liposomes were investigated.•Phycocyanin restricted the motion of liposomes polar and interfacial groups.•Phycocyanin disrupted the package of liposomes hydrophobic region.•Phycocyanin have the strongest interaction with liposomes carbonyl groups.•These effects were correlated to Phycocyaninʾs antiradical/ antioxidant properties. This study describes the physicochemical properties of soybean asolectin (ASO) liposomes loaded with phycocyanin (Phy) extracted from Spirulina sp. LEB 18. The effects of Phy in the liposomesʾ properties were investigated by Fourier transform infrared spectroscopy (FTIR), 1H and 31P nuclear magnetic resonance (NMR), zeta (ζ)-potential, dynamic light scattering (DLS) and ultraviolet-visible (UV–vis) techniques. Phy restricted the motion of ASO polar and interface groups and disrupted the package arrangement of the lipid hydrophobic regions, as a likely effect of dipolar and π interactions related to its amino acid residues and pyrrole portions. These interactions were correlated to antiradical/antioxidant Phy responses obtained by 2,2-diphenyl-1-picrylhidrazil (DPPH) assay, thiobarbituric acid reactive substances (TBARS) and ferric reducing antioxidant power (FRAP) methods, and discussed to bring new chemical perspectives about Phy-loaded liposomes-related nutraceutical applications in inflammatory and viral infection processes.