Enrichment of flavonoid aglycones in licorice extract enhanced anti-inflammatory potential,but its hypnotic effect was not altered

OBJECTIVE Licorice is used throughout the world as a traditional herbal remedy.According 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.

Differential transcriptional regulation of the NANOG gene in chicken primordial germ cells and embryonic stem cells

Background:NANOG is a core transcription factor(TF)in embryonic stem cells(ESCs)and primordial germ cells(PGCs).Regulation of the NANOG gene by TFs,epigenetic factors,and autoregulatory factors is well characterized in ESCs,and transcriptional regulation of NANOG is well established in these cells.Although NANOG plays a key role in germ cells,the molecular mechanism underlying its transcriptional regulation in PGCs has not been studied.Therefore,we investigated the mechanism that regulates transcription of the chicken NANOG(cNANOG)gene in PGCs and ESCs.Results:We first identified the transcription start site of cNANOG by 5′-rapid amplification of cDNA ends PCR analysis.Then,we measured the promoter activity of various 5′flanking regions of cNANOG in chicken PGCs and ESCs using the luciferase reporter assay.cNANOG expression required transcriptional regulatory elements,which were positively regulated by POU5F3(OCT4)and SOX2 and negatively regulated by TP53 in PGCs.The proximal region of the cNANOG promoter contains a positive transcriptional regulatory element(CCAAT/enhancer-binding protein(CEBP)-binding site)in ESCs.Furthermore,small interfering RNA-mediated knockdown demonstrated that POU5F3,SOX2,and CEBP played a role in cell type-specific transcription of cNANOG.Conclusions:We show for the first time that different trans-regulatory elements control transcription of cNANOG in a cell type-specific manner.This finding might help to elucidate the mechanism that regulates cNANOG expression in PGCs and ESCs.