Hepatoprotective protein pigment complex phycocyanin from Spirulina maxima and its potential antimicrobial, oxidative stress-modulating effects

In the present study, the antibacterial activity and oxidative stress-modulating effects of phycocyanin extracted from Spirulina maxima were investigated. Phycocyanin was isolated from S. maxima biomass using cold maceration, followed by ammonium sulfate precipitation and column chromatography. The purified phycocyanin was screened for antibacterial activity against pathogenic bacterial strains, Escherichia coli and Staphylococcus aureus , by determining the zone of inhibition, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The oxidative stress-modulating potential of phycocyanin was evaluated in a zebrafish model by analyzing oxidative stress markers, including catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione peroxidase (GPO), lipid peroxidase (LPO), and reduced glutathione (GSH). In addition, the gene expression of key oxidative stress markers was assessed using quantitative real-time PCR (qRT-PCR), and the hepatoprotective activity of phycocyanin was examined by measuring hepatic enzymes such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Phycocyanin derived from algal biomass effectively inhibited the growth of bacterial strains, as demonstrated by MIC and MBC results. Antioxidant studies in the zebrafish oxidative stress model revealed that phycocyanin administration significantly modulated oxidative stress without inducing hepatotoxicity or tissue damage. Overall, these findings suggest that algal-derived phycocyanin is a promising bioactive compound with dual functions as an effective antimicrobial and a potent modulator of oxidative stress, offering excellent biocompatibility for potential therapeutic applications against infectious and oxidative stress-related diseases. • Highly stable protein pigment complex phycocyanin with notable antioxidative potential was extracted from Spirulina maxima. • Phycocyanin exhibited an oxidative stress modulatory effect against the H 2 O 2 -induced zebrafish model. • No sign of toxic effect on the hepatic enzymes and tissue organisation revealed the hepato-protective activity of phycocyanin. • Extracted phycocyanin revealed high antibacterial activity against human pathogenic bacterial strains.