Purification and antioxidant activity of phycocyanin from Synechococcus sp. R42DM isolated from industrially polluted site

•The cyanobacterium Synechococcus sp. R42DM is isolated and identified.•Combined use of Triton X-100 and ultra-sonication is noted optimum for cell lysis.•Phycocyanin (PC) is purified from Synechococcus cell-extract.•Synechococcus PC shows significant in vitro and in vivo antioxidant activity.•Synechococcus PC is proposed to be used as nutraceutical and anti-aging molecule. The cyanobacterium Synechococcus sp. R42DM, isolated from an industrially polluted site Vatva, Gujarat, India was recognized to produce phycocyanin (PC) as major phycobiliprotein. In present study, the combinatorial approach of chemical and physical methods i.e. Triton-X 100 treatment and ultra-sonication was designed for extraction of PC. From cell extract, the intact and functional-PC was purified up to purity 4.03 by ammonium sulphate fractionation and ion-exchange chromatography. The PC displayed considerable in vitro antioxidant and radical-scavenging activity. This PC was further noticed to scavenge intracellular-ROS and to increase tolerance against thermal and oxidative stress in Caenorhabditis elegans. Moreover, the PC was noticed to improve the physiological behaviour and longevity of C. elegans. In addition, the PC showed remarkable stability under physico-chemical stressors, which is desirable for their use in biomedical applications. In conclusion, present paper added up evidence in support of the prospective use of PC as an antioxidant nutraceutical.