[Aryl Hydrocarbon Receptor Ligand Activity of Extracts from 62 Herbal Medicines and Effect on Cytochrome P450 Activity].

Aryl hydrocarbon receptor (AhR) ligand activity of the extracts of 62 herbal medicines was examined using yeast reporter assay. Fifty-eight herbal extracts exhibited AhR ligand activity. The highest activity was observed with Ogon (Scutellariae Radix), followed by Oren (Coptidis Rhizoma), Kujin (Sophorae Radix) and Shoma (Cimicifiigae Rhizoma). When these extracts were treated with hesperinase, a hydrolase for sugar conjugates, the aglycones showed higher activity than the parent extracts. Among the constituents of Ogon extract, baicalein and wogonin showed AhR ligand activity, while the sugar conjugate of baicalein, baicalin, was inactive. Among the flavonoid components of these herbal medicines, flavone and chrysin exhibited high ligand activity for AhR. Ethoxyresorufin O-dealkylase (EROD) activity due to CYP1A1 in HepG2 cells was enhanced by the addition of baicalein. Baicalein also decreased the 3-methylcholanthrene-induced increase of EROD activity, but this effect was not statistically significant. When wogonin or baicalein was orally administered at the dose of 100 mg/kg to mice, EROD activity in liver was only slightly changed. Furthermore, when Ogon extract was co-administered with 3-methylcholanthrene, the EROD and methoxyresorufin O-dealkylase activities were not significantly changed. These results indicate that many herbal extracts have AhR ligand activity, and their inducing effect on CYP1A1/2 can be evaluated in HepG2 cells.

Analysis and comparison of Radix Glycyrrhizae (licorice) from Europe and China by capillary-zone electrophoresis (CZE).

A simple capillary-zone electrophoresis (CZE) method for the analysis of plant specimens, Glycyrrhiza glabra L., G. uralensisFisch. and G. inflata Bat. (Leguminosae) as well as commercial licorices from Europe and China was developed. Contents of glycyrrhizin (GL), glycyrrhetic acid (GA), glabridin (GLAB), liquiritin (LQ) and licochalcone A (LC(A)) in ethanolic extracts were investigated. Optimum separation was achieved with sodium tetraborate buffer (pH 9.22; 70 mM); voltage, 25 kV. Recovery rate for GL was found to be 101.90+/-2.54%. Adequate correlation was observed between GL contents measured by CZE and HPLC (r=0.977). Advantages over conventional HPLC analysis of Glycyrrhiza species are short analysis time (<15 min), simple running buffer preparation and the none-use of organic solvents. Using the present CZE method, it was demonstrated that (1) G. glabra was distinguished from G. uralensis especially by phenolic compounds GLAB (G. glabra: 0.19+/-0.11%; n=53) and LQ (G. uralensis, 1.34+/-0.34%, n=10); (2) on average, GL contents were higher in Chinese commercial licorices; (3) relatively high LC(A) contents were especially detected in a Chinese commercial licorice (origin estimated as G. inflata); (4) Glycyrrhiza species were also distinguished by applying PCA on the basis of CZE peak area data of GL, GLAB, GA, LQ and LC(A); and (5) liquiritin apioside was found in all samples.

[Study on identification of wild and cultirated Radix Scutellariae in different growing years].

OBJECTIVE: To identify Radix Scutellariae (Huangqin) of different growth years, to distinguish whether it's wild or cultivated and to provide useful information for the quality control of Huangqin crude drug. METHOD: By using morphological and histological methods, we studied 87 individuals of 45 specimens from 12 habitats of 5 provinces of China, which grew wild or were cultivated in different growing years. Moreover, 22 commercial samples of Huangqin from 7 provinces were also investigated. RESULT: The identification was performed base on morphological and histological characteristics, such as, the shape, color, cork, remaining stems, decayed central xylem, and vessels arrangement, xylem cork ring, growth rings, etc. CONCLUSION: We established an identification method for distinguishing Huangqin wild or cultivated in different growing years. Furthermore, the structure of annual rings in the transection of Radix Scutellariae has been discovered for the first time.

Glycosyl flavonoids from the roots and rhizomes of Asarum longerhizomatosum.

Two new glycosyl flavonoids including a glycosyl aurone, together with six known flavonoids were isolated from the roots and rhizomes of Asarum longerhizomatosum. The structures of the two new compounds were elucidated as 4,6,4'-trihydroxy-aurone-4,6-di-O-beta-D-glucopyranoside (7, caulesauroneside) and naringenin-7,4'-di-O-beta-D-glucopyranoside (8, caulesnarinside). The six known flavonoids were identified as naringenin (1), naringenin-5-O-beta-D-glucopyranoside (2), naringenin-7-O-beta-D-glucopyranoside (3), chalcononaringenin-2'-O-beta-D-glucopyranoside (4), naringenin-5,7-di-O-beta-D-glucopyranoside (5), chalcononaringenin-2',4'-di-O-beta-D-glucopyranoside (6), respectively. This is the first report of the isolation of aurones in the family Aristolochiaceae.

Quantitative analysis of tropane alkaloids in biological materials by gas chromatography-mass spectrometry.

A simple and rapid method for quantitation of tropane alkaloids in biological materials has been developed using an Extrelut column with gas chromatography-mass spectrometry (GC-MS). Biological materials (serum and urine) were mixed with a borate buffer and then applied to an Extrelut column. The adsorbed tropane alkaloids were eluted with dichloromethane before a GC-MS analysis. Atropine-d(3) was used as an internal standard. The extracted tropane alkaloids were converted to trimethylsilyl derivatives prior to GC analysis, to improve the instability of tropane alkaloids from heating and the property of them for a GC column. The recoveries of the compounds, which had been spiked to biological materials, were more than 80%. The GC separation of the derivatives from endogenous impurities was generally satisfactory with the use of a semi-polar capillary column. Tropane alkaloids showed excellent linearity in the range of 10-5000 ng/ml and the limit of detection was 5.0 ng/ml for biological materials. The present method is simple and more rapid than those previously reported, and was applied to a poisoning case. It is useful for the routine analysis of tropane alkaloids in cases of suspected tropane alkaloids poisoning.

Evaluation of variation of acteoside and three major flavonoids in wild and cultivated Scutellaria baicalensis roots by micellar electrokinetic chromatography.

Micellar electrokinetic chromatography (MEKC) conditions were developed to analyze the constituents of Scutellariae Radix (SR) and Scutellaria baicalensis roots. Using the MEKC method, the major flavonoid constituents of baicalin, baicalein and wogonin of wild and cultivated S. baicalensis roots were compared. In a preliminary comparison of electropherogram, one special peak was found in a wild sample but not in a 2-year-cultivated one. The compound corresponding to the peak was isolated and identified as a phenylethanoid glycoside, acteoside, by comparing the 1H- and 13C-NMR spectral data with that of the authentic compound. This is the first time acteoside has been isolated from the Scutellaria genus. It could only be found in SR derived from wild S. baicalensis roots and 4-year-cultivated plants, but not in plant materials cultivated for 3 years. Applying the MEKC method established in this study, rapid and simultaneous determinations of acteoside together with 3 flavonoids in samples were achieved. The method can thus be used for the quality control of SR in a shorter analysis period than HPLC.