Development of a novel method for the extraction of phycocyanin pigment from Spirulina platensis and assessment of its antioxidant, antimicrobial, and anticancer activities

Phycocyanin (PC), a primary light-harvesting pigment derived from Spirulina platensis, finds extensive application owing to its biological properties. In this study, we present an efficient procedure for the extraction of PC pigment, followed by a thorough exploration of its biological activities. A novel extraction method, involving a four-step process including cell lysis through freeze-thawing, maceration, centrifugation, and tangential microfiltration, was employed, resulting in purity index of 1.32. The crude PC was analyzed by UV–visible and FTIR spectroscopy. SDS-PAGE analysis showed two bonds corresponding to α (17 kDa) and β (20 kDa) subunits of PC. The crude PC was examined for its antioxidant activity through diverse antioxidants assays, including assessments of DPPH radical-scavenging capacity, reducing power, and ABTS assay. In addition, assays assessing antimicrobial activity revealed significant inhibitory effects of the crude PC against various bacterial and fungal strains. The inhibitory effect of crude PC on the proliferation of human breast cancer cells (MCF-7) was detected by MTT assay. Interestingly, crude PC was most active with 59.2% of cell proliferation inhibition at 4 mg/mL, while it exhibits greater safety and lower toxicity on normal cell lines (HEK-293). Moreover, the application of crude PC in a dose-dependent manner to MCF-7 cells led to the inhibition of cell migration as observed in the wound healing assay. In summary, these findings suggest that crude PC holds promise for its utilization as valuable functional and bioactive components in the food and nutraceutical sectors.