Antioxidant activity of Cyanobacteria isolated from Cochin estuary

Abstract

Antioxidant activity of methanolic extracts of three Cyanobacteria, <i>Oscillatoria limosa</i> C.Agardh ex Gomont, <i>Synechococcus elongates</i> (Nägeli) Nägeli and <i>Synechocystis aquatilis</i> var. minor Geitler isolated from Cochin estuary was studied. Phycobiliproteins were analysed, phycocyanin and allophycocyanin were the major pigments in <i>O. limosa</i> and <i>S. aquatilis</i> while phycoerythrin was the major one in <i>S. elongatus</i>. Total phenolic content, total antioxidant activity and nitric oxide scavenging activity was maximum in <i>O. limosa</i> (33.4µg GAE±0.45, 97µg AE±0.327 and 55.16%±0.51. Superoxide radical scavenging activity was shown maximally by <i>S. elongatus</i> (97%±0.871) followed by <i>O. limosa</i> (91.5%±0.781) and lowest in <i>S. aquatilis</i> (90.66%±0.611). <i>S. aquatilis</i> maximally inhibited lipid peroxidation (94.47%±0.472).