Study on Extracting Crude Phycocyanin from Spirulina Algae and Determining Its Ability in Protecting Fibroblasts from Oxidative Stress of Hydroxyl Peroxide

Phycocyanin is a powerful natural antioxidant from Arthrospira platensis. In this study, crude phycocyanin (crPC) was extracted, and its ability to protect fibroblast from hydroxyl peroxide (H₂O₂) in vitro was determined. crPC was extracted from Spirulina by a step-by-step method: 1/cell breaking by a repeated freezing/thawing method; 2/contaminant removal by 8% active charcoal and ammonium sulfate 15%; 3/phycocyanin obtaining by ammonium sulfate 50% and dialysis. Abilities of crPC 6, 12.5, 25, 50 and 75 μg/mL in inducing cell proliferation and migration were tested on fibroblasts. The protective ability of crPC against oxidative stress of H₂O₂ was determined on fibroblasts as the following method: fibroblasts were pretreated with crPC 25 μg/mL for 24 h before exposing to H₂O₂ 175 μM for 90 min (experimental group). Then cell viability, cell phase and senescence β-galactosidase expression were evaluated. The results showed that: PI of crPC was 2.79 ± 0.03 and concentration was 1.13 ± 0.05 (n = 5). crPC below 150 μg/ml was non-toxic to fibroblasts and crPC above 25 μg/mL stimulated cell proliferation (doubling time was 44.5 ± 1.2 h, n = 3) and migration (24 h, n = 3). Compared to control group (cells were treated only with H₂O₂ 175 μM), cell viability in the experimental group was higher (79.3 ± 5.4% vs. 53.4 ± 2.3%, n = 3) and cell ratio in G0/G1 and senescence β-galactosidase expression was lower (78.7 ± 4.1% vs. 85.8 ± 6.1%) (22.8 ± 4.6% vs. 68.4 ± 6.8%). Conclusion: crPC was extracted successfully from Arthospira platensis, and crPC 25 μg/mL was able to protect fibroblast against oxidative stress of H₂O₂.