title: Antioxidant capacity of betacyanins as radical scavengers for peroxyl radical and nitric oxide.
abstract: This study was designed to assess the antioxidant capacity of betacyanins as indole derived plant pigments, such as betanin, phyllocactin and betanidin. The antioxidant capacity of the betacyanins was evaluated as an index of radical scavenging ability using the peroxyl radical generating system in the presence of AAPH and NO generating system using NOR3 as an NO donor. The peroxyl radical scavenging capacity was dose-dependent in the low concentration range (25-100 nM). The mol-Trolox equivalent activity/mol compound (mol-TEA/mol-compound) as an index of the antioxidant capacity indicated the following order at 10.70 ± 0.01, 3.31 ± 0.14 and 2.83 ± 0.01 mol-TEA/mol-compound for betanidin, betanin and phyllocactin, respectively. In addition, betacyanins reduced the nitrite-level in the low concentration range of 2.5-20 μM. The IC₅₀ values (μM) of nitrogen radical scavenging activity were 24.48, 17.51 and 6.81 for betanin, phyllocactin and betanidin. ESR studies provided evidence that the compounds directly scavenged NO. These results indicated that betacyanins have a strong antioxidant capacity, particularly betanidin with a catechol group had higher activity than those of the glycoside of betacyanins. This study demonstrated that the betacyanins will be useful as natural pigments to provide defence against oxidative stress.
authors: Department of Bioresource Technology, Okinawa National College of Technology, 905 Henoko, Nago City, Okinawa 905-2192, Japan. Electronic address: taira@okinawa-ct.ac.jp.
authors: Junsei
authors: J
authors: Taira
authors: Department of Bioresource Technology, Okinawa National College of Technology, 905 Henoko, Nago City, Okinawa 905-2192, Japan.
authors: Eito
authors: E
authors: Tsuchida
authors: Department of Bioresource Technology, Okinawa National College of Technology, 905 Henoko, Nago City, Okinawa 905-2192, Japan.
authors: Megumi C
authors: MC
authors: Katoh
authors: Department of Bioresource Technology, Okinawa National College of Technology, 905 Henoko, Nago City, Okinawa 905-2192, Japan.
authors: Masatsugu
authors: M
authors: Uehara
authors: Okinawa Industrial Technology Center, 12-2 Suzaki, Uruma City, Okinawa 904-2234, Japan.
authors: Takayuki
authors: T
authors: Ogi
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D050859:Betacyanins / Q000737:chemistry*; D029421:Cactaceae / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D005638:Fruit / Q000737:chemistry; D009569:Nitric Oxide / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry
chemical_list: D000975:Antioxidants; D050859:Betacyanins; D010545:Peroxides; D010936:Plant Extracts; C508222:phyllocactin; C049375:perhydroxyl radical; D009569:Nitric Oxide; C020228:betanin
keywords: Antioxidant; Betacyanin; ESR; Hylocereus polyrhizus; Nitric oxide; Peroxyl radical