Phycocyanin oral delivery system obtained by spray-drying with soy proteins for the treatment of inflammatory bowel diseases: in vivo evaluation

Phycocyanin (PC), a bioactive pigment from Spirulina, exhibits strong antioxidant and anti-inflammatory properties but faces limitations in stability and bioavailability. This study aimed to develop and characterize soy protein-based microparticles (MPs MilcS-PC) using a spray-drying technique to enhance PC's therapeutic potential for inflammatory bowel disease (IBD). Physicochemical characterization (UV-Vis and FT-IR spectroscopy, SEM, XRPD, and DSC) confirmed that PC was effectively encapsulated within the microparticles, improving its solubility and stability. In vitro antioxidant assays demonstrated that MPs MilcS-PC preserved PC's radical scavenging activity. At the same time, dissolution and ex vivo permeation studies revealed a controlled release profile, protecting PC in gastric conditions and enhancing its intestinal permeability. Moreover, biocompatibility tests confirmed the safety of MPs MilcS-PC Fibroblasts, while cytotoxicity assays in Caco-2 cells suggested a dual role in intestinal inflammation management and potential anticancer effects. In vivo, MPs MilcS-PC significantly reduced inflammation in a DNBS-induced colitis rat model, reduced macroscopic damage, and decreased myeloperoxidase activity and IL-6 expression compared to free PC. Bioavailability studies confirmed that encapsulation improved PC absorption. These findings highlight MPs MilcS-PC as a promising delivery system, enhancing PC's stability, bioavailability, and therapeutic efficacy in IBD treatment, encouraging future clinical applications in chronic inflammatory diseases.