Oxygen radical absorbance capacity of phycocyanin and phycocyanobilin from the food supplement Aphanizomenon flos-aquae.
The oxygen radical absorbance capacity (ORAC) assay has been widely used to quantify peroxyl radical scavenging capacity of pure antioxidant compounds and antioxidant plant/food extracts. However, it has never been applied to natural compounds derived from microalgae-based dietary supplements, namely, phycocyanin (PC) and phycocyanobilin (PCB), for which a strong radical scavenger activity has been documented. In this article, we applied the ORAC method to investigate the capacity of PC and PCB purified from the edible microalga Aphanizomenon flos-aquae to directly quench peroxyl radicals in comparison to well-known antioxidants molecules such as Trolox, ascorbic acid, and reduced glutathione. As a result, PCB was found to have the highest ORAC value (22.18 micromol of Trolox/micromol of compound), comparable to that of PC (20.33 micromol of Trolox/micromol of compound), hence confirming that PCB is mostly responsible for the scavenger activity of PC and making the protein a possible source of the antioxidant in vivo. Our data further corroborate the use of these natural compounds from A. flos-aquae as dietary antioxidant supplements in the treatment of clinical conditions related to oxidative stress.
Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy. serena.benedetti@uniurb.it
Serena
S
Benedetti
Francesca
F
Benvenuti
Stefano
S
Scoglio
Franco
F
Canestrari
D000975:Antioxidants / Q000494:pharmacology*; D046890:Aphanizomenon / Q000737:chemistry*; D001205:Ascorbic Acid / Q000494:pharmacology; D002839:Chromans / Q000494:pharmacology; D019587:Dietary Supplements; D005978:Glutathione / Q000494:pharmacology; D018384:Oxidative Stress; D010545:Peroxides / Q000378:metabolism*; D052980:Phycobilins / Q000494:pharmacology*; D010798:Phycocyanin / Q000494:pharmacology*; D028321:Plant Preparations / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism
D000975:Antioxidants; D002839:Chromans; D010545:Peroxides; D052980:Phycobilins; D028321:Plant Preparations; D017382:Reactive Oxygen Species; D010798:Phycocyanin; C011069:phycocyanobilin; D005978:Glutathione; D001205:Ascorbic Acid; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid