Title : Comparative bioactivity of sequentially purified Spirulina maxima extracts for cosmeceutical applications
Abstract:
Spirulina maxima, a microalga rich in bioactive pigments, proteins, and polysaccharides, has attracted increasing attention as a sustainable source of natural ingredients for skincare and cosmeceutical formulations. However, the extent to which purification affects the biological activities of Spirulina-derived compounds remains insufficiently understood. This study therefore compared the chemical characteristics and skin-related functional activities of crude and purified Spirulina extracts. Five samples were prepared through sequential processing steps involving water extraction, buffer extraction, dialysis, ammonium sulfate precipitation, and ion-exchange chromatography. Pigment and polysaccharide contents were determined to characterize the major bioactive constituents, while the purity and molecular characteristics of phycocyanin were assessed using sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) and UV–Vis spectrophotometry. The functional properties of the samples were evaluated in RAW 264.7 macrophages, B16-F10 melanoma cells, and human dermal fibroblasts (HDFa), representing cellular models relevant to oxidative stress, melanogenesis, and skin aging. Among the tested samples, the water extract exhibited the strongest intracellular reactive oxygen species (ROS) scavenging activity. It also significantly inhibited the expression of the tyrosinase gene (TYR), suggesting potential anti-melanogenic and skin-whitening activity, while enhancing the expression of collagen type I alpha 1 chain (COL1A1) in dermal fibroblasts. Furthermore, under UVB-induced oxidative stress conditions, the water extract effectively suppressed matrix metalloproteinase-1 (MMP1) expression, indicating its potential to protect collagen from UVB-associated degradation and prevent wrinkle formation. Notably, these functional effects were greater than those observed for the purified phycocyanin fractions, suggesting that multiple water-soluble constituents may act additively or synergistically. Collectively, these findings demonstrate that simple water extraction can preserve multifunctional bioactive compounds from S. maxima and provide antioxidant, whitening, and anti-aging activities. The water extract may therefore serve as a natural, sustainable, and cost-effective functional ingredient for future cosmeceutical applications.
