title: C-phycocyanin: a potent peroxyl radical scavenger in vivo and in vitro.
abstract: C-Phycocyanin (from Spirulina platensis) effectively inhibited CCl(4)-induced lipid peroxidation in rat liver in vivo. Both native and reduced phycocyanin significantly inhibited peroxyl radical-induced lipid peroxidation in rat liver microsomes and the inhibition was concentration dependent with an IC(50) of 11.35 and 12.7 microM, respectively. The radical scavenging property of phycocyanin was established by studying its reactivity with peroxyl and hydroxyl radicals and also by competition kinetics of crocin bleaching. These studies have demonstrated that phycocyanin is a potent peroxyl radical scavenger with an IC(50) of 5.0 microM and the rate constant ratios obtained for phycocyanin and uric acid (a known peroxyl radical scavenger) were 1.54 and 3.5, respectively. These studies clearly suggest that the covalently linked chromophore, phycocyanobilin, is involved in the antioxidant and radical scavenging activity of phycocyanin.
authors.affiliation: Department of Organic Chemistry, Indian Institute of Science, Bangalore, 560 012, India.
authors.forename: V B
authors.initials: VB
authors.lastname: Bhat
authors.forename: K M
authors.initials: KM
authors.lastname: Madyastha
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D001426:Bacterial Proteins; D001894:Borohydrides / Q000378:metabolism; D002251:Carbon Tetrachloride / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002338:Carotenoids / Q000378:metabolism; D016166:Free Radical Scavengers / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D005609:Free Radicals / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology; D017665:Hydroxyl Radical / Q000378:metabolism; D020128:Inhibitory Concentration 50; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects; D013058:Mass Spectrometry; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D010084:Oxidation-Reduction; D010545:Peroxides / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D052980:Phycobilins; D010798:Phycocyanin / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D011758:Pyrroles / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D013053:Spectrophotometry; D053545:Spirulina; D045725:Tetrapyrroles; D014527:Uric Acid / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D001426:Bacterial Proteins; D001894:Borohydrides; D016166:Free Radical Scavengers; D005609:Free Radicals; D010545:Peroxides; D052980:Phycobilins; D011758:Pyrroles; D045725:Tetrapyrroles; D010798:Phycocyanin; D014527:Uric Acid; C049375:perhydroxyl radical; D017665:Hydroxyl Radical; D002338:Carotenoids; C011069:phycocyanobilin; C029036:crocin; C025364:sodium borohydride; D002251:Carbon Tetrachloride