In vitro: |
Life Sci. 2002 Aug 9;71(12):1449-63. | Anti-Helicobacter pylori flavonoids from licorice extract.[Pubmed: 12127165] | Licorice is the most used crude drug in Kampo medicines (traditional Chinese medicines modified in Japan).
METHODS AND RESULTS:
The extract of the medicinal plant is also used as the basis of anti-ulcer medicines for treatment of peptic ulcer. Among the chemical constituents of the plant, glabridin and glabrene (components of Glycyrrhiza glabra), licochalcone A (G. inflata), licoricidin and licoisoflavone B (G. uralensis) exhibited inhibitory activity against the growth of Helicobacter pylori in vitro. These flavonoids also showed anti-H. pylori activity against a clarithromycin (CLAR) and amoxicillin (AMOX)-resistant strain. We also investigated the methanol extract of G. uralensis. From the extract, three new isoflavonoids (3-arylcoumarin, pterocarpan, and isoflavan) with a pyran ring, gancaonols A[bond]C, were isolated together with 15 known flavonoids. Among these compounds, vestitol, licoricone, 1-methoxyphaseollidin and gancaonol C exhibited anti-H. pylori activity against the CLAR and AMOX-resistant strain as well as four CLAR (AMOX)-sensitive strains. Glycyrin, formononetin, isolicoflavonol, glyasperin D, 6,8-diprenylorobol, gancaonin I, dihydrolicoisoflavone A, and gancaonol B possessed weaker anti-H. pylori activity.
CONCLUSIONS:
These compounds may be useful chemopreventive agents for peptic ulcer or gastric cancer in H. pylori-infected individuals. | Biol Pharm Bull. 1999 Oct;22(10):1144-6. | Inhibition of lysoPAF acetyltransferase activity by components of licorice root.[Pubmed: 10549875] | METHODS AND RESULTS:
Licorice root traditionally used as an anti-inflammatory drug exhibited an inhibitory effect on lysoPAF (platelet-activating factor) acetyltransferase in vitro: the ether soluble fraction of the crude drug produced a 27.3% inhibition at a concentration 10 microg/ml. From this fraction, licoricidin (1), 1-methoxyphaseollin (2), 6,8-diprenylgenistein (3) and 1-methoxyphaseollidin (4) were isolated as active components, whose IC50 values were 7.7, 57, 19 and 48 microM, respectively.
CONCLUSIONS:
Licoricidin (1) seems to be one of the most potent compounds of plant origin isolated so far. |
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