Radical scavenging activity of Acer nikoense Maxim. extract.

The effect of hot water and alkaline extracts of Acer nikoense Maxim. on the radical intensity of sodium ascorbate, superoxide anion (O2-)(produced by hypoxanthine-xanthine oxidase reaction) and hydroxyl radical (-OH)(generated by Fenton reaction) was investigated using ESR spectroscopy. All these extracts produced radical(s) under alkaline conditions and enhanced the radical intensity of sodium ascorbate. Among these fractions, Fr. I showed the highest stimulation effect, which coincided with its higher degradation rate and capacity to enhance the cytotoxic activity of ascorbate. These fractions also dose-dependently reduced the radical intensity of O2- and -OH. The present study demonstrates that Acer nikoense Maxim. extracts potentiate both radical intensity and apoptosis-inducing activity of ascorbate.