Radical scavenging and xanthine oxidase inhibitory activity of phenolic compounds from Bridelia ferruginea stem bark

Citation
K. Cimanga et al., Radical scavenging and xanthine oxidase inhibitory activity of phenolic compounds from Bridelia ferruginea stem bark, J PHARM PHA, 53(5), 2001, pp. 757-761
Citations number
20
Categorie Soggetti
Pharmacology & Toxicology
Journal title
JOURNAL OF PHARMACY AND PHARMACOLOGY
ISSN journal
00223573 → ACNP
Volume
53
Issue
5
Year of publication
2001
Pages
757 - 761
Database
ISI
SICI code
0022-3573(200105)53:5<757:RSAXOI>2.0.ZU;2-J
Abstract
Bridelia ferruginea Benth. (Euphorbiaceae) is a subtropical medicinal plant widely used in traditional African medicine against various diseases. incl uding rheumatic pains. Seven of its constituents (3-O-methylquercetin (1), 3,7,3'.4'-tetra-O-methylquercetin (rutisin, 2), myricetin (3), 3',4',5'-tri -O-methylmyricetin (ferrugin, 4), 3,3'.4'.5'-tetra-O-methylmyricretin (5), quercetin 3-O-glucoside (6), and a biflavanol gallocatechin-[4'-O-7]-epigal locatechin (7)) have been evaluated in-vitro in the xanthine-xanthine oxida se enzymatic system for inhibition of xanthine oxidase and radical scavengi ng activity. Results indicated that compounds 1, 3, 4 and 6 exhibited, at d ifferent levels, xanthine oxidase inhibiting and superoxide scavenging acti vity at micromolarconcentrations, whereas compound 7 showed scavenging acti vity only. Compounds 2 and 5 were inactive in both cases. Study of the stru cture-activity relationship demonstrated that for flavonoids the xanthine o xidase inhibitory activity was reduced by methylation of the hydroxyl funct ionality at C-3 and in rings A and B. These results may partly explain and support the use of B. ferruginea stem bark for the treatment of rheumatic p ains in traditional medicine.