5.6 - In vitro Superoxide Anion Radical Scavenging Ability of Honeybush Tea (Cyclopia)

Abstract

The superoxide anion radical (O2-) scavenging ability of aqueous extracts from honeybush tea, as affected by species and fermentation, and phenolic compounds from fermented C. intermedia, was evaluated. Unfermented C. sessiliflora showed the strongest O2- scavenging ability. Fermentation significantly (P ≤ 0.05) decreased the O2- scavenging ability of the different species. A strong structure-activity relationship was illustrated by the relative O2- scavenging efficacy of the phenolic compounds. The flavone luteolin and the flavanone eriodictyol showed excellent O2- scavenging activity compared to the flavanones, hesperidin and hesperetin. The isoflavone formononetin and coumestan medicagol were not effective scavengers of this radical.