Protection of free radical-induced cytotoxicity by 2-O-α-d-glucopyranosyl-l-ascorbic acid in human dermal fibroblasts

Abstract

The stable ascorbic acid (AA) derivative, 2-O-α-d-glucopyranosyl-l-ascorbic acid (AA-2G), exhibits vitamin C activity after enzymatic hydrolysis to AA. The biological activity of AA-2G per se has not been studied in detail, although AA-2G has been noted as a stable source for AA supply. The protective effect of AA-2G against the oxidative cell death of human dermal fibroblasts induced by incubating with 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) for 24 h was investigated in this study. AA-2G showed a significant protective effect against the oxidative stress in a concentration-dependent manner. AA-2G did not exert a protective effect during the initial 12 h of incubation, but had a significant protective effect in the later part of the incubation period. Experiments using a α-glucosidase inhibitor and comparative experiments using a stereoisomer of AA-2G confirmed that AA-2G had a protective effect against AAPH-induced cytotoxicity without being converted to AA. Our results provide an insight into the efficacy of AA-2G as a biologically interesting antioxidant and suggest the practical use of AA-2G even before being converted into AA as a beneficial antioxidant.

Graphical Abstract

2-O-α-D-Glucopyranosyl-L-ascorbic acid without being converted to ascorbic acid protected against free radical-induced cytotoxicity in human dermal fibroblasts.

Key words:

• 2-O-α-d-glucopyranosyl-l-ascorbic acid
• stable vitamin C derivative
• water-soluble antioxidant
• oxidative stress
• AAPH

Acknowledgments

We thank Hayashibara Biochemical Laboratories (Okayama, Japan) for the supply of AA-2G.