In vitro: |
Appl Environ Microbiol. 2003 Oct;69(10):5849-54. | Anaerobic degradation of flavonoids by Clostridium orbiscindens.[Pubmed: 14532034] | METHODS AND RESULTS:
An anaerobic, quercetin-degrading bacterium was isolated from human feces and identified as Clostridium orbiscindens by comparative 16S rRNA gene sequence analysis. The organism was tested for its ability to transform several flavonoids. The isolated C. orbiscindens strain converted quercetin and taxifolin to 3,4-dihydroxyphenylacetic acid; luteolin and eriodictyol to 3-(3,4-dihydroxyphenyl)propionic acid; and apigenin, naringenin, and phloretin to 3-(4-hydroxyphenyl)propionic acid, respectively. Genistein and daidzein were not utilized.
CONCLUSIONS:
The glycosidic bonds of luteolin-3-glucoside, Luteollin 5-glucoside, naringenin-7-neohesperidoside (naringin), quercetin-3-glucoside, quercetin-3-rutinoside (rutin), and phloretin-2'-glucoside were not cleaved. | Planta Med., 2011, 13(5):1-12. | Relationship between chemical structure and antioxidant activity of luteolin and its glycosides isolated from thymus sipyleus subsp. sipyleus var. sipyleus.[Reference: WebLink] | One triterpenic acid (ursolic acid), one phenolic acid (rosmarinic acid), and four flavonoids (luteolin, luteolin 7-O-(6"-feruloyl)-β-glucopyranoside, luteolin 5-O-β-glucopyranoside(Luteollin 5-glucoside ), and luteolin 7-O-β-glucuronide) were isolated from the aerial parts of Thymus sipyleus subsp. sipyleus var. sipyleus and identified by spectroscopic methods.
METHODS AND RESULTS:
In vitro lipid peroxidation inhibition effects of the compounds were determined using TBA test method in a bovine brain liposome system. All compounds inhibited lipid peroxidation in various degrees except for ursolic acid. The order of the lipid peroxidation activities of luteolin, its glycosides and rosmarinic acid were: Luteolin 7-O-β-glucuronide> luteolin 5-O-β-glucopyranoside(Luteollin 5-glucoside )> luteolin 7-O-(6"-feruloyl)- β-glucopyranoside > rosmarinic acid >luteolin. However, the activity order of the compounds was completely different in DPPH radical-scavenging activity. None of the compounds shows Fe 2+ chelating activity. The results were discussed based on their chemical structures and polarities. | Food Chem Toxicol . 2012 Jun;50(6):2171-9. | Anti-inflammatory activity of Korean thistle Cirsium maackii and its major flavonoid, luteolin 5-O-glucoside[Pubmed: 22525859] | Abstract
The anti-inflammatory activity of whole Cirsium maackii (family Compositae) plants and of its major flavonoid, luteolin 5-O-glucoside, was evaluated for their ability to inhibit lipopolysaccharide (LPS)-induced nitric oxide (NO) production, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) protein expression, and tert-butylhydroperoxide (t-BHP)-induced reactive oxygen species (ROS) generation in RAW 264.7 murine macrophage cells. The methanolic extract of C. maackii showed strong anti-inflammatory activity, and was thus fractionated with several solvents. The ethyl acetate-soluble fraction, exhibiting the highest anti-inflammatory activity potential, was further to yield a major flavonoid, luteolin 5-O-glucoside. We found that luteolin 5-O-glucoside, at a non-toxic concentration, inhibited LPS-induced NO production and t-BHP-induced ROS generation in a dose-dependent manner in RAW 264.7 cells. It also suppressed the expression of iNOS and COX-2 in LPS-stimulated macrophages. Furthermore, the efficacies of the methanolic extract of C. maackii in inhibiting both NO and ROS were attributed to its flavonoid content by HPLC analysis. These results indicated that C. maackii whole plants and its flavonoids inhibit the expression of iNOS and COX-2 in through the inhibition of ROS generation, and therefore can be considered as a useful therapeutic and preventive approach for the treatment of various inflammatory and oxidative stress-related diseases.
Copyright © 2012 Elsevier Ltd. All rights reserved. |
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