Abstract:Comparative studies on the antioxidant activity of phycobiliprotein crude extract，phycocyanin and phycoerythrin in artificial farming Nostoc sphaeroides were developed in vitro.The activity of antioxidant was evaluated through detecting hydroxyl radical scavenging，superoxide anion radical scavenging，and lipid peroxidation inhibition in vitro.Antioxidant tests demonstrated that phycobiliprotein crude extract，phycocyanin and phycoerythrin showed significant antioxidant activity，but three different proteins exerted antioxidant activity through different ways.In hydroxyl radical scavenging tests，the orders of effect from strong to weak were from phycobiliprotein crude extract，phycocyanin to phycoerythrin，while in superoxide anion radical scavenging tests，the orders of effect from strong to weak were from phycoerythrin，phycocyanin to phycobiliprotein crude extract.In lipid peroxidation inhibition tests，the orders of effect from strong to weak were from phycoerythrin，phycobiliprotein crude extract to phycocyanin.Antioxidant tests demonstrated that phycobiliprotein crude extract，phycocyanin and phycoerythrin from artificial farming Nostoc sphaeroides showed significant antioxidant activity through different ways.