Pharmaceutical evaluation of Glycyrrhiza uralensis roots cultivated in eastern Nei-Meng-Gu of China

Research Progress on the Mechanism of Reducing Toxicity and Increasing the Efficacy of Sini Decoction Compatibility

Sini Decoction (SND) is the main prescription for treating Shaoyin disease in Zhang Zhongjing's Treatise on Typhoid Diseases in Han Dynasty. It is composed of Aconitum carmichaeli Debeaux, Glycyrrhiza uralensis Fisch ex DC and Zingiber officinale Roscoe. It has the effects of warming middle-jiao to dispel cold and revive the yang for resuscitation. Nowadays, it is mainly used in diseases in cardiovascular system, nervous system, digestive system and so on. In this paper, the effect and mechanism of the compatibility of Aconitum carmichaelii, Glycyrrhiza uralensis Fisch ex DC and Zingiber officinale Roscoe in SND were described. The results showed that SND performed remarkbly on strengthening heart, promoting blood circulation as well as inhibiting cardiomyocyte apoptosis, anti-inflammatory and anti-hypothyroidism. The toxic effect of Aconitum carmichaelii was relieved by the combination of Glycyrrhiza uralensis Fisch ex DC and Zingiber officinale Roscoe. The mechanism of increasing efficiency and reducing toxicity after the compatibility of medicines in SND was discussed from the perspective of changes in biological effects and chemical compositions. In terms of biological effects, the mechanism of SND in treating heart failure, myocardial ischemia, myocardial hypertrophy and hypothyroidism and protecting cell injury were discussed. As to chemical composition changes, most studies have compared the changes of main components in Aconitum carmichaelii, Glycyrrhiza uralensis Fisch ex DC and Zingiber officinale Roscoe with the whole prescription, drug pair and single Decoction, which further confirmed the effect of Glycyrrhiza uralensis Fisch ex DC on the detoxification of Aconitum carmichaelii and the significance of compatibility efficiency of SND. For the application of differently processed varieties of Aconitum carmichaelii in SND, the treatment of different diseases has siginificant tendencies and differences in the selections of Aconitum carmichaelii processed varieties. This paper will lay a foundation on clarifying the mechanism of drug compatibility of SND and in the future, provide a reference for the proper selection of differently processed products of Aconitum carmichaelii in SND in order to exert better effects in clinical pratices.

Effect of glucoglycyrrhizin on IgE-mediated immediate hypersensitivity in mice

To evaluate the pharmacological property of glucoglycyrrhizin (GGL), a unique glycoside of glycyrrhetinic acid (GA), we investigated the anti-allergic effect of GGL on IgE-mediated immediate hypersensitivity in mice. GGL exhibited the antiallergic effect against IgE-mediated immediate hypersensitivity. At a dose of 100 mg/kg, GGL exhibited antiallergic activity equivalent to that of glycyrrhizin (GL). Furthermore, the pretreatment with anti-GA monoclonal antibody eliminated the antiallergic action of GGL. These results indicated that GGL may act in the same way as GL in the human body. Its safety should be verified for its use as a drug similar to GL.

Evaluation of the safety and efficacy of Glycyrrhiza uralensis root extracts produced using artificial hydroponic and artificial hydroponic-field hybrid cultivation systems III: anti-allergic effects of hot water extracts on IgE-mediated immediate hypersensitivity in mice

To evaluate the safety and efficacy of Glycyrrhiza uralensis root extracts produced using artificial hydroponic and artificial hydroponic-field hybrid cultivation systems, we investigated anti-allergic action in mice using IgE-mediated immediate hypersensitivity. Hot water extracts obtained from the roots of Glycyrrhiza uralensis cultivated using two systems were orally administered at a dose of 100 mg/kg as glycyrrhizin (GL) and compared with the commercial crude drug, Glycyrrhizae Radix. Both the artificial hydroponic and artificial hydroponic-field hybrid cultivated root extracts showed anti-allergic effects on IgE-mediated immediate hypersensitivity in mice, as did the commercial crude drugs. These results highlight the potential for artificially cultivated roots of Glycyrrhiza uralensis to be used as an alternative medicinal source.

Evaluation of the safety and efficacy of Glycyrrhiza uralensis root extracts produced using artificial hydroponic and artificial hydroponic-field hybrid cultivation systems

Glycyrrhiza uralensis roots used in this study were produced using novel cultivation systems, including artificial hydroponics and artificial hydroponic-field hybrid cultivation. The equivalency between G. uralensis root extracts produced by hydroponics and/or hybrid cultivation and a commercial Glycyrrhiza crude drug were evaluated for both safety and efficacy, and there were no significant differences in terms of mutagenicity on the Ames tests. The levels of cadmium and mercury in both hydroponic roots and crude drugs were less than the limit of quantitation. Arsenic levels were lower in all hydroponic roots than in the crude drug, whereas mean lead levels in the crude drug were not significantly different from those in the hydroponically cultivated G. uralensis roots. Both hydroponic and hybrid-cultivated root extracts showed antiallergic activities against contact hypersensitivity that were similar to those of the crude drug extracts. These study results suggest that hydroponic and hybrid-cultivated roots are equivalent in safety and efficacy to those of commercial crude drugs. Further studies are necessary before the roots are applicable as replacements for the currently available commercial crude drugs produced from wild plant resources.

The influence of compatibility of processed radix Aconiti Kusnezoffii on the pharmacokinetic of four components in Glycyrrhiza uralensis Fisch

ETHNOPHARMACOLOGICAL RELEVANCE

Glycyrrhiza uralensis Fisch. and processed radix Aconiti kusnezoffii are the main components in many Chinese traditional patent medicines with the ratio of 1:1, which are used for treatment of rheumatoid arthritis, heart failure and so on. Glycyrrhizic acid, glycyrrhetic acid, liquiritigenin and isoliquiritigenin are the essential bioactive triterpenes and flavones in the extract of G. uralensis, which were analysis by a simple but accurate method.

MATERIALS AND METHODS

In the present study, a specific HPLC method was developed and validated for simultaneous determination of pharmacokinetic parameters of glycyrrhizic acid, glycyrrhetic acid, liquiritigenin and isoliquiritigenin in G. uralensis after oral administration of single herb extract and a combination of two herbs extracts respectively.

RESULTS

The calibration curves of the four components had good linearity higher than 0.9991 in the measured range. The intra-day and inter-day precisions (RSD) at different levels were both within 9.73%, and the accuracies (RE) were in the range of -7.9-8.0%. Compared with pharmacokinetic parameters of G. uralensis administered orally, values of AUC and Cmax of liquiritigenin and isoliquiritigenin decreased significantly (p<0.05), plasma concentrations of glycyrrhizic acid rose slightly and bimodal phenomenon of concentration-time of isoliquiritigenin and glycyrrhetinic acid disappeared after combined administration.

DISCUSSION AND CONCLUSIONS

Some components in the extract of processed radix A. kusnezoffii showed different effects on the pharmacokinetics of the four ingredients in G. uralensis.

Aim for production of Glycyrrhizae Radix in Japan (3): development of a new licorice cultivar

The development of cultivars is indispensable for the establishment of a method aimed at producing licorice in Japan. The cultivar should have the following attributes: (1) the underground parts should grow vigorously; (2) the glycyrrhizin (GL) content must be 2.5 % or greater; and (3) the architecture of the aerial parts should be erect. A new cultivar suitable for the domestic production of licorice was developed by crossbreeding between strain A-19 (with a high GL content) as the mother and strain G-6 (with vigorous growth) as the father. After 2 years of cultivation, strain C-2 exhibited vigorous growth; the fresh weight and stem diameter were 148.8 g and 0.89 mm, respectively. Moreover, the dry-weight GL and total flavonoid contents of the new cultivar (strain C-2) from cultured plants were 3.61 and 1.365 %, respectively.

Pharmacokinetic study of four flavones of Glycyrrhiza in rat plasma using HPLC-MS

AIM OF THE STUDY

This study aimed to develop a specific HPLC-MS method for simultaneous quantification of four flavones of Glycyrrhiza in rat plasma after oral administration and to describe the pharmacokinetics of four flavones in rat plasma.

MATERIALS AND METHODS

A simple, sensitive and selective method for simultaneous determination of four flavones of Glycyrrhiza in rat plasma, i.e., liquiritin, isoliquiritin, liquiritigenin, and isoliquiritigenin, by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS) with negative electrospray ionization mode, was developed and validated. The method was applied to investigate the pharmacokinetics of four flavones in rat plasma after oral administration of Glycyrrhiza flavones. Chromatographic separation was accomplished on an Agilent TC-C18 column (4.6mm×250mm, and 5μm), with gradient elution by using a mixture of methanoic acid (A) and acetonitrile (B) as the mobile phase at a flow rate of 0.8mL/min.

RESULTS

The calibration curves for four flavones had good linearity higher than 0.997 in the measured range. Relative standard deviations (RSDs) of the intra- and inter-day precision at different levels were all less than 4.8%. The pharmacokinetic profile of four flavones in rat plasma was fitted with a two-compartment model detected by a simple, rapid and accurate HPLC-MS method. Time (h) to reach peak concentration (μg/mL) of liquiritin (2.69±0.04), isoliquiritin (10.16±0.02), liquiritigenin (2.83±0.02), and isoliquiritigenin (0.28±0.01) was 2.02±0.23, 1.97±0.20, 0.48±0.02, and 1.93±0.36, respectively. The distribution and elimination half-life (h) and area under the concentration-time curve (μg/mL-h) from t=0 to last time of liquiritin, isoliquiritin, liquiritigenin, and isoliquiritigenin were 1.02±0.48/2.27±0.53/16.97±0.43, 2.04±1.01/2.38±0.80/69.20±5.24, 0.35±0.10/4.26±0.16/14.83±0.11, and 1.18±0.32/3.04±0.22/2.10±0.09, respectively. Isoliquiritin presented the phenomenon of double peaks and the others appeared together in a single and plateau absorption phase. Isoliquiritigenin had the lowest oral bioavailability because of Cmax and AUC0-∞. Liquiritigenin had the fastest absorption and distribution rate and the lowest elimination rate according to Tmax, t1/2α, and t1/2β.

CONCLUSIONS

This paper first reported on identification and determination of four flavones of Glycyrrhiza in rat plasma and their respective pharmacokinetic characteristics. The results provided a meaningful basis for better understanding the absorption mechanism of Glycyrrhiza and evaluating the clinical application of this medicine.

Pharmaceutical evaluation of liquorice before and after roasting in mice

Liquorice has been used for allergic-inflammatory and liver disorders in both traditional Chinese and modern medicine. In traditional Chinese formulations, it is mainly roasted liquorice that has been used rather than un-roasted liquorice. We have compared the pharmaceutical characteristics of liquorice before and after roasting to clarify the pharmaceutical significance of the roasting. Although roasted liquorice contained less glycyrrhizin (an anti-allergic component) than un-roasted liquorice, the inhibitory potency of roasted liquorice extract (200 mg kg−1) on immunoglobulin E (IgE)-mediated triphasic ear swelling in mice was much greater compared with un-roasted liquorice. To search for additional active ingredients, roasted liquorice extract was subjected to gel-chromatography to give an anti-allergic fraction (Fa) of molecular weight ranging from 15000 to 200000 or more, in which glycyrrhizin was not detected. By testing the activity of the various fractions, it was proved that the anti-allergic effect of roasted liquorice was due to glycyrrhizin, its metabolite glycyrrhetic acid, and the Fa fraction. The inhibitory potency of the Fa fraction (15 and 75 mg kg−1) prepared from roasted liquorice was stronger than that prepared from un-roasted liquorice. Therefore, a pharmaceutical implication of roasting the liquorice seems to be associated with an increase in the anti-allergic property of the Fa fraction. It is notable that oral administration of the high molecular mass fraction (Fa) significantly inhibited IgE-mediated ear swelling six days after challenge at doses as low as 3, 15 or 75 mg kg−1.

Effects of space flight on DNA mutation and secondary metabolites of licorice (Glycyrrhiza uralensis Fisch.)

Licorice (Glycyrrhiza uralensis Fisch.) seeds were flown on a recoverable satellite for 18 days(the average radiation dose in the flight recovery module was 0.102 mGy/d, the distance from flight apogee to earth was 350 km, gravity 10(-6)). After returning to earth, the seeds were germinated and grown to maturity. The parallel ground-based seeds were also planted under the same conditions. The leaves of licorice were used for inter-simple sequence repeat (ISSR) analysis and the two main secondary metabolites in one-year-old roots were analyzed by high performance liquid chromatography (HPLC). Among 22 random primers used in this experiment, 6 primers generated different DNA band types. Analysis of HPLC showed that the content of glycyrrhizic acid (GA) and liquiritin (LQ) in the roots from seeds flown in space was respectively 2.19, 1.18 times higher than that of the control group. The results demonstrated that the extraterrestrial environment induced mutagenic effects on licorice and affected its secondary metabolites. These changes indicated that extraterrestrial orbit is possible means of breeding of licorice so as to preserve this endangered medicinal plant.

One-step immunochromatographic separation and ELISA quantification of glycyrrhizin from traditional Chinese medicines

The bioactive constituent, glycyrrhizin or glycyrrhizic acid (GA), was purified from two traditional Chinese medicines (TCM), Shaoyao gancao tang and Dahuang gancao tang, and from crude extracts from licorice roots by means of immunoaffinity chromatography using anti-GA monoclonal antibody (MAb) and was quantified with an enzyme-linked immunosorbent assay (ELISA). Laboratory preparations included the synthesis of conjugate GA-human serum albumin (GA-HSA), the production of anti-GA-MAb, the optimization of the immunoaffinity column packed with the anti-GA-MAb coupled to hydrazide gel and the determination of the GA content in TCM and crude drugs from five different sources by ELISA and high performance liquid chromatography (HPLC). The experimental results reveal that the anti-GA-MAb coupled to Affi-Gel Hz gel results in a coupling efficiency of 95.2%, and the immunoaffinity chromatography gives a mean recovery of 97.6% of GA with a capacity of 33.5+/-2.40 microg/mL of immunoaffinity gel under the given conditions. The GA content of the crude extracts (ranging 74.8-114.6 microg/mg) from different sources by the ELISA method is much greater than that of the TCM (16.4-25.1 microg/mg) which is, in good agreement with the results of the HPLC method. Our report provides a rapid, reliable and sensitive approach for one-step separation and quantification of GA.

Pharmaceutical evaluation of cultivated Glycyrrhiza uralensis roots in comparison of their antispasmodic activity and glycycoumarin contents with those of licorice

In China, the collection of wild Glycyrrhiza uralensis, one of the raw materials of Chinese licorice, has been restricted to prevent desertification. To compensate for the reduced supply of wild Glycyrrhiza plants, cultivation programs of G. uralensis have been initiated in eastern Inner Mongolia. The goal of the present study was to compare the chemical and pharmacological properties of cultivated G. uralensis roots to those of licorice prepared from wild Glycyrrhiza plants. The antispasmodic effect of boiled water extract of 4-year-old cultivated G. uralensis roots and licorice on carbachol-induced contraction in mice jejunum was similar (ED(50): 134+/-21 microg/ml vs. 134+/-16 microg/ml). In addition, glycycoumarin content, which is an antispasmodic and species-specific ingredient of G. uralensis, was similar when comparing the boiled water extracts of 4-year-old cultivated roots and licorice (0.10+/-0.02% vs. 0.10+/-0.06%). These data suggest that cultivated G. uralensis roots may be an adequate replacement for the generation of licorice in the context of the restriction of wild Glycyrrhiza plant collection.

Emerging issues in traditional Chinese medicine

Traditional Chinese medicine (TCM) has many beneficial effects and has been practiced for several thousand years. It is known to treat the cause of a disease rather than to alleviate its symptoms. Based on a belief that TCM is natural, safe, and of lower cost, consumers worldwide are spending more out-of-pocket money on this form of therapy. This increased spending, and reports of adverse reactions, has drawn the attention of many regulatory agencies. Scientists have called for more evidence-based and scientific research on the risks and benefits of TCM. In Canada, the Natural Health Product Regulations came into effect January 2004. TCM herbal product manufacturers will need to provide products of reputable quality to the market. Many will apply modern technology and good science to support their products. The issues facing producers, scientists, and consumers alike are quality control and assessment, standardization of bioactive components, mechanisms of actions, and integration of the evolved modern Chinese medicine into the healthcare system. Solid science, better regulation of the final product, and better education of consumers are necessary to extract the best of TCM to complement existing conventional medicine to deliver the best healthcare.Key words: bioactive components, chromatographic fingerprinting, integration, mechanisms, Natural Health Product (NHP) Regulations, standardization, traditional Chinese medicine.

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.

Comparative Analysis of Ten Strains of Glycyrrhiza uralensis Cultivated in Japan

Comparative analysis of 10 strains of Glycyrrhiza uralensis cultivated in Kyoto, Japan, was undertaken to characterize their variations. Based on the chemical characteristics of their leaves and underground parts, the 10 strains were divided into two chemotypes, the China type and Kazakhstan type. The contents of licoleafol in the leaves of the China type (0-0.03% of dry weight) were lower than those of the Kazakhstan type (0.05-1.16% of dry weight). In addition, a China type-specific unidentified compound was also detected in the leaves of China-type plants. Glycyrrhizin contents in the underground parts of the China type (2.08-5.12% of dry weight) were relatively higher than those of the Kazakhstan type (0.75-2.55% of dry weight). Contents of glycycoumarin, a species-specific flavonoid of G. uralensis, in the underground parts of China-type plants (0.07-0.28% of dry weight) were higher than those of Kazakhstan-type plants (0.01-0.08% of dry weight). These 10 strains were also divided into two genotypes, the GA type and AT type, based on their chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit gene (rbcL) sequences, although there was no correlation between the chemotype and the rbcL genotype.