Anti-Inflammatory and Anti-Urolithiasis Effects of Polyphenolic Compounds from Quercus gilva Blume

Quercus gilva Bume (QGB, family Fagaceae) is a tall evergreen oak species tree that grows in warm temperate regions in Korea, Japan, China and Taiwan. Quercus plants have long been the basis of traditional medicines. Their clinical benefits according to traditional medicine include relief of urolithiasis, tremors and inflammation. In the present study, the anti-urolithiasis activity including anti-inflammatory and anti-oxidative activities, of some phenolic compounds isolated from QGB were described. Seven compounds were isolated and identified as picraquassioside D (1), quercussioside (2), (+)-lyoniresinol-9′α-O-β-d-xylopyranoside (3), (+)-catechin (4), (−)-epicatechin (5), procyanidin B-3 (6), and procyanidin B-4 (7). Compounds 5–7 showed potent anti-oxidative and anti-inflammatory activities. These compounds were further tested for their inhibition of the gene expression of the inflammatory cytokines. The three compounds 5–7 showed dose-dependent inhibitory activities on gene expression of COX-2 and IL-1β. In vivo, urolithiasis was induced more effectively in an animal model of acute urolithiasis by the administration of QGB extract. These results indicate the potential of compounds from QGB in the treatment of urolithiasis.