Radical scavenging activity of Alkanna tinctoria root extracts and their main constituents, hydroxynaphthoquinones
Article first published online: 25 APR 2005
Copyright © 2005 John Wiley & Sons, Ltd.
Volume 19, Issue 2, pages 141–147, February 2005
How to Cite
Assimopoulou, A. N. and Papageorgiou, V. P. (2005), Radical scavenging activity of Alkanna tinctoria root extracts and their main constituents, hydroxynaphthoquinones. Phytother. Res., 19: 141–147. doi: 10.1002/ptr.1645
- Issue published online: 25 APR 2005
- Article first published online: 25 APR 2005
- Manuscript Accepted: 14 DEC 2004
- Manuscript Received: 12 JUL 2004
- Alkanna tinctoria;
- radical scavenging activity;
Alkannin and shikonin (A[sol ]S) are pharmaceutical substances with a wide spectrum of biological properties. Radical scavenging activity is involved in aging processes, antiinßammatory, anticancer and wound healing activities. Hence, in the present study the DPPH radical scavenging activity of alkannin and shikonin, both monomeric and oligomeric, and extracts of Alkanna tinctoria roots were studied and a structure–activity relationship was approximated.
It was shown that both monomeric and oligomeric alkannin and shikonin and also A[sol ]S esters exhibited extremely high radical scavenging activity. The presence of the naphthoquinone moiety seems to be essential for that activity, while the side chain of A[sol ]S possibly plays a minor role. Esterification of A[sol ]S on the side chain hydroxyl group does not affect radical scavenging activity. Organic solvents and olive oil (extracted at room temperature) extracts of Alkanna tinctoria roots, which contain as active ingredients A[sol ]S esters, exhibited very good antiradical activity.
Alkannin and shikonin and their esters and also extracts of Alkanna tinctoria roots could be used promisingly in pharmaceutical and cosmetic preparations for their radical scavenging activity and probably for their antiaging activity. Copyright © 2005 John Wiley & Sons, Ltd.