In VitroAnti-Inflammatory Effects of Quercetin 3-O-Methyl Ether and Other Constituents fromRhamnusSpecies

Abstract

The anti-inflammatory activities of the isolated flavonoids, quercetin 3-O-methyl ether (1), kaempferol (2), and quercetin (3), of Rhamnus nakaharai, and anthraquinone, frangulin B (4), of Rhamnus formosana, were assessed in vitro by determining their inhibitory effects on the chemical mediators released from mast cells, neutrophils, macrophages, and microglial cells. Compounds 1 - 3 strongly inhibited the release of beta-glucuronidase and lysozyme from rat neutrophils stimulated with formyl-Met-Leu-Phe/cytochalasin B (fMLP/CB). Compound 1 strongly inhibited superoxide anion formation in fMLP/CB or phorbol 12-myristate 13-acetate (PMA)-stimulated rat neutrophils. Compound 1 exhibited potent inhibitory effect on tumor-necrosis factor-alpha ( TNF-alpha) formation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells while 1 and 4 showed potent inhibitory effects on TNF-alpha formation in LPS/IFN-gamma (interferon-gamma)-stimulated murine microglial cell lines N9.

Flavonoids with anti-inflammatory and antinociceptive activity from Cistus laurifolius L. leaves through bioassay-guided procedures

“…Through bioassay-guided fractionation procedures three flavonoids, 3-O-methylquercetin (1), 3,7-O-dimethylquercetin (2) and 3,7-O-dimethylkaempferol (3), were isolated as the potent antinociceptive and anti-inflammatory principles. Although 1 was previously reported to possess in vivo anti-inflammatory activity (Wei et al, 2001), this is the first report on the in vivo antiinflammatory and antinociceptive effects of other flavonoids 2 and 3. A remarkable point might be the potency of these flavonoids, which was found to be equal to that of indomethacin, a well-known anti-inflammatory agent, without inducing any apparent acute toxicity or gastric damage.…”

“…It should be noted that 3,7-O-dimethylquercetin (2) was isolated as one of the active anti-inflammatory and antinociceptive principles of the leaves in the present study. Wei et al (2001) revealed that 3-O-methylquercetin (1) (also known as isorhamnetin) as the active anti-inflammatory principle of Rhamnus species and it is suggested that a possible activity mechanism is through inhibition of histamine release from peritoneal mast cells, as well as the release of ␤-glucuronidase and lysozyme from and superoxide anion formation from rat neutrophils. 3-O-methylquercetin (1) was also reported to inhibit the development of cotton-pellet-induced granuloma in mice (Pelzer et al, 1998) and in vitro xanthine oxidase inhibitory activity (Cimanga et al, 2001).…”

Prostaglandin inhibitory and antioxidant components of Cistus laurifolius, a Turkish medicinal plant

“…The degranulation of mast cells and neutrophils and the activation of macrophages and microglial cells contribute to inflammatory disorders. The compound inhibited the release of histamine from peritoneal mast cells, the release of ␤-glucuronidase and lysozyme from rat neutrophils and superoxide anion formation from rat neutrophils (Wei et al, 2001), and exhibited xanthine oxidase inhibitory and superoxide scavenging activities (Cimanga et al, 2001). It also inhibited carrageenan-induced mouse paw edema, and both 1 and genkwanin (3) were reported to inhibit the development of cotton-pellet-induced granuloma in mice (Pelzer et al, 1998).…”

Inhibition of Prostate Cancer Cell Colony Formation by the Flavonoid Quercetin Correlates with Modulation of Specific Regulatory Genes

“…Although quercetin, in general, has been reported to be anti-inflammatory (34), previous studies (26,39) have shown that quercetin exerts significant modulatory effects on gene expression as well as protein synthesis of both pro-and antiinflammatory molecules. A previous study (26) showed that quercetin up-regulated the Th-1-derived proinflammatory cytokine gamma interferon, while it reciprocally inhibited the Th-2-derived anti-inflammatory cytokine interleukin-4.…”