Enrichment of flavonoid aglycones in licorice extract enhanced anti-inflammatory potential,but its hypnotic effect was not altered
- Author:
Xue-Qiong ZHANG
1
;
Hwa-Jin KIM
;
Su-Ying CUI
;
Tae-Jun BAE
;
Xiang-Yu CUI
;
Soo-Geun LEE
;
Bae-Hyeong PYO
;
Yong-He ZHANG
Author Information
1. Department of Pharmacology
- Keywords:
anti-inflammation;
flavonoid aglycon;
grifola frondosa HB0071;
hypnotic;
Licorice
- From:
Chinese Journal of Pharmacology and Toxicology
2018;32(4):337-338
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE Licorice is used throughout the world as a traditional herbal remedy. Ac-cording to Chinese traditional medicine licorice alone can be used to treat inflammation.Although there have been some studies investigated the anti-inflammatory ingredients of licorice, but for the potency of flavonoid glycoside and their aglycones on inflammation are not evaluated.This study was designed to assess the contributions of licorice flavonoid glycosides and their aglycons to its anti-inflammatory and hypnotic effects. METHODS For the flavonoid aglycone's enrichment, the extract of licorice (EL) was fermented in submerged culture of the edible fungus Grifola frondosa HB0071 mycelia which can produce β-glucosidase and catalyze the flavonoid glycosides to aglycones.EL and fermented extract of licorice (FEL) were used in this study. The anti-inflammation test was carried out in arachidonic acid (AA)-induced ear edema model and the hypnotic test was performed by using electroencephalogram (EEG)analysis method in normal freely moving SD rats.The chemicals constituents were analyzed by HPLC.RESULTS During fermentation,the falvonoid glycosides of licorice were hydrolyzed by the time process.Along with fermentation time,the concentration of the major flavonoid glycosides,liquiritin and isoliquiritin were decreased obviously, and simultaneously their aglycons, liquiritigenin and isoliquiriti-genin were remarkably increased in FEL.Moreover,the content of another major constituent glycyrrhi-zic acid and glycyrrhetinic acid were not changed after the fermentation. In AA-induced mice ear ede-ma test,after topical application,FEL(effective dose range:5-20 μg·ear-1)showed more potent inhibito-ry activity than EL(effective dose range:25-100 μg·ear-1).On the other hand,oral administration of EL and FEL exhibited the same hypnotic potency and both enhanced the total sleep time including rapid eye movement (REM) sleep and non-REM sleep time. CONCLUSION These results suggested that the enrichment of flavonoid aglycons such as liquiritigenin and isoliquiritigenin enhanced the anti-inflam-matory potency of licorice extract,and this potentiation has nothing to do with glycyrrhizic acid or glycyr-rhetinic acid.In addition,enrichment of flavonoid aglycones did not alter the hypnotic effect of licorice.
