Reassessment of antioxidant activity of arbutin: multifaceted evaluation using five antioxidant assay systems.
ABSTRACT Arbutin, a practically used skin-lightening agent, has been reported to possess a weak antioxidant activity compared to that of its precursor, hydroquinone. However, its antioxidant activity has not been systematically evaluated. Hence, this study reassessed its activity using five assay systems. Assays were first performed using model radicals, DPPH radical and ABTS(*+). Arbutin showed weak DPPH radical-scavenging activity compared to that of hydroquinone, but showed strong ABTS(*+)-scavenging activity. Its activity by ORAC assay was then evaluated using a physiologically relevant peroxyl radical. Arbutin exerted weak but long-lasting radical-scavenging activity and showed totally the same antioxidant activity as that of hydroquinone. Finally, it was shown that, in two cell-based antioxidant assays using erythrocytes and skin fibroblasts, arbutin exerted strong antioxidant activity comparable or even superior to that of hydroquinone. These findings indicate that the antioxidant activity of arbutin may have been under-estimated and suggest that it acts as a potent antioxidant in the skin.
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ABSTRACT: 2-O-β-D-Glucopyranosyl-L-ascorbic acid (AA-2βG) is a natural derivative of vitamin C (Lascorbic acid, AA) isolated from Goji berry (Lycium barbarum L.) fruit. We evaluated the antioxidant activities of AA-2βG and AA using in vitro and in vivo model systems. In vitro radical scavenging assays demonstrated that AA-βG was capable of scavenging 1,1-diphenyl-2-picryl-hydrazyl and hydroxyl peroxide and inhibiting H(2)O(2)-induced hemolysis better than AA. AA-2βG and AA had similar hydroxyl radical scavenging capabilities, but AA-2βG was incapable of scavenging superoxide anion radicals, and its capacity to scavenge nitrite (NO(2) (-)) was lower than that of AA. The overall in vitro reduction capability of AA-2βG was also significantly lower than that of AA. Moreover, in vivo studies demonstrated that AA-2βG was capable of protecting the liver against carbon tetrachloride-induced acute liver injury in mice. These results suggest that AA-2βG is an important antioxidant component of Goji berry fruit, which may share similar but distinct antioxidant mechanistic properties with AA. This study furthers our understanding of the mechanisms of Goji berry fruit pharmacological activities on antiaging and antitumor properties as a traditional medicine and dietary supplement.Archives of Pharmacal Research 05/2011; 34(5):801-10. · 1.54 Impact Factor
- Gastroenterology 01/2011; 140(5). · 12.82 Impact Factor