Phormidium versicolor PC skin cream evaluation for its stability and biological activities

In the present investigation, 13% ± 0.84 of the extracted and purified phycocyanin from Phormidium versicolor was obtained, with a purity of 0.69 following dialysis. FT-IR analysis of purified phycocyanin revealed stretching vibration peaks in the profiles of the functional groups of N-H, O-H, C = O, N-H, C = O, and C = NH⁺. The phycocyanin had a significant DPPH radical scavenging ability (IC₅₀ = 0.6 ± 0.02 mg mL^-1) confirmed with FRAP assay, and it exhibited microbiological activity between 1.25 and 2.5 mg mL^-1 against Candida albicans, Klebsiella pneumoniae, and Enterococcus faecalis. Phycocyanin showed no cytotoxic and improved the viability of HEK-293. It was added to skin cream at a rate of 6 mg g^-1 because of its significant yield extraction and biological activity. At 10 mg mL^-1, a bactericidal activity has been noted, inhibiting the growth of bacteria responsible for inflammatory skin conditions. For 60 days, the emulsion's stability was monitored at room temperature, 25 °C, and 45 °C. The appearance of the batch kept at 45 °C was changed to beige after 7 days, while the others were kept for 15 days. Skin creams enhanced with phycocyanin were found to be stable over the course of storage at both room temperature and 25 °C, based on centrifugation stability analysis. But starting on the fifteenth day, the items kept at 45 °C were unstable. Thus, the current study's findings are in favor of using phycocyanin as an antioxidant in cosmetic products. However, further investigation is required before using it in clinical trials. KEY POINTS: • Phycocyanin extraction field (13%) is particularly significant compared to other cyanobacteria. • Phycocyanin at 0.6 microg g-1 in skin cream fights bacteria in skin inflammation. • Phycocyanin-enriched cream was stable at room temp, 25 °C, and unstable at 45 °C after day 15.