Determination of glycyrrhetic acid in human plasma by HPLC-MS method and investigation of its pharmacokinetics

Exploration of material basis: Chemical composition profile, metabolic profile and pharmacokinetic characteristics in Xingbei Zhike granule

HEADINGS ETHNOPHARMACOLOGICAL RELEVANCE

Xingbei Zhike granule (XBZK), a widely prescribed Chinese patent medicine, is known for its efficacy in clearing lung qi, relieving cough and reducing phlegm, as well as fever, dry and bitter taste, and irritability. Despite its clinical popularity, comprehensive investigations into its chemical composition, in vivo metabolism, and pharmacokinetic characteristics are limited.

AIM OF THE STUDY

This study investigates the chemical composition, in vivo metabolism, and in vivo dynamics of XBZK to clarify its material basis and pharmacokinetic characteristics.

MATERIALS AND METHODS

Ultra-high performance liquid chromatography with Orbitrap tandem mass spectrometry (UPLC-Orbitrap-MS) was used to determine the chemical composition and in vivo metabolic profile of XBZK. Additionally, UPLC with triple quadrupole mass spectrometry (UPLC-TQ-MS/MS) was performed to quantify its main components and evaluate its in vivo dynamics in rat plasma.

RESULTS

In total, 57 components were identified in XBZK. Furthermore, 40 prototype components and 31 metabolites were detected in various biological matrices of rats, including plasma, tissues, bile, feces, and urine. After administration, the area under the curve (AUC) for ephedrine (Eph), pseudoephedrine (Peph), neotuberostemonine (Neo), amygdalin (Amy), and enoxolone (Eno) exhibited a strong linear relationship with the administered dose (r > 0.9) in all rats. And gender-related differences in the absorption of peiminine (Pmn), peimisine (Pms), and chrysin-7-O-glucuronide (Cog) were notable among rats, with male rats showing a dose-dependent pattern of absorption, while female rats exhibited minimal absorption.

CONCLUSIONS

XBZK contains 57 components, primarily composed of flavonoids, alkaloids, and coumarins. The eight main components were rapidly absorbed and eliminated, with some, such as Eph, Peph, Neo, Amy and Eno, following a linear pharmacokinetic pattern. Furthermore, Pmn, Pms and Cog were well absorbed in male rats, showing a dose-dependent behavior.

Ursolic Acid-Based Derivatives as Potential Anti-Cancer Agents: An Update

Ursolic acid is a pharmacologically active pentacyclic triterpenoid derived from medicinal plants, fruit, and vegetables. The pharmacological activities of ursolic acid have been extensively studied over the past few years and various reports have revealed that ursolic acid has multiple biological activities, which include anti-inflammatory, antioxidant, anti-cancer, etc. In terms of cancer treatment, ursolic acid interacts with a number of molecular targets that play an essential role in many cell signaling pathways. It suppresses transformation, inhibits proliferation, and induces apoptosis of tumor cells. Although ursolic acid has many benefits, its therapeutic applications in clinical medicine are limited by its poor bioavailability and absorption. To overcome such disadvantages, researchers around the globe have designed and developed synthetic ursolic acid derivatives with enhanced therapeutic effects by structurally modifying the parent skeleton of ursolic acid. These structurally modified compounds display enhanced therapeutic effects when compared to ursolic acid. This present review summarizes various synthesized derivatives of ursolic acid with anti-cancer activity which were reported from 2015 to date.

Natural Products as Modulators of CES1 Activity

Carboxylesterase (CES) 1 is the predominant esterase expressed in the human liver and is capable of catalyzing the hydrolysis of a wide range of therapeutic agents, toxins, and endogenous compounds. Accumulating studies have demonstrated associations between the expression and activity of CES1 and the pharmacokinetics and/or pharmacodynamics of CES1 substrate medications (e.g., methylphenidate, clopidogrel, oseltamivir). Therefore, any perturbation of CES1 by coingested xenobiotics could potentially compromise treatment. Natural products are known to alter drug disposition by modulating cytochrome P450 and UDP-glucuronosyltransferase enzymes, but this issue is less thoroughly explored with CES1. We report the results of a systematic literature search and discuss natural products as potential modulators of CES1 activity. The majority of research reports reviewed were in vitro investigations that require further confirmation through clinical study. Cannabis products (Δ ⁹-tetrahydrocannabinol, cannabidiol, cannabinol); supplements from various plant sources containing naringenin, quercetin, luteolin, oleanolic acid, and asiatic acid; and certain traditional medicines (danshen and zhizhuwan) appear to pose the highest inhibition potential. In addition, ursolic acid, gambogic acid, and glycyrrhetic acid, if delivered intravenously, may attain high enough systemic concentrations to significantly inhibit CES1. The provision of a translational interpretation of in vitro assessments of natural product actions and interactions is limited by the dearth of basic pharmacokinetic data of the natural compounds exhibiting potent in vitro influences on CES1 activity. This is a major impediment to assigning even potential clinical significance. The modulatory effects on CES1 expression after chronic exposure to natural products warrants further investigation. SIGNIFICANCE STATEMENT: Modulation of CES1 activity by natural products may alter the course of treatment and clinical outcome. In this review, we have summarized the natural products that can potentially interact with CES1 substrate medications. We have also noted the limitations of existing reports and outlined challenges and future directions in this field.

Effects of diammonium glycyrrhizinate on hepatic and intestinal UDP-Glucuronosyltransferases in rats: Implication in herb-drug interactions

Glycyrrhizin is a major bioactive component of liquorice, which exerts multiple biochemical and pharmacological activities and is frequently used in combination with other drugs in the clinic. Mycophenolate mofetil (MMF), an immunosuppressant widely used in transplant patients, is metabolized by UDP-glucuronyltransferases (UGTs). Although significant evidence supports that glycyrrhizin could interact with the cytochrome P450s (CYPs), few studies have addressed its effects on UGTs. The present study aimed at investigating the regulatory effects of diammonium glycyrrhizinate (GLN) on UGTs in vitro and in vivo. We found that long-term administration of GLN in rats induced overall metabolism of MMF, which might be due to the induction of UGT1A protein expression. Hepatic UGT1A activity and UGT1A mRNA and protein expression were significantly increased in GLN-treated rats. UGT1A expression levels were also increased in the intestine, contradicting with the observed decrease in intestinal UGT1A activities. This phenomenon may be attributed to different concentrations of glycyrrhetinic acid (GA) in liver and intestine and the inhibitory effects of GA on UGT1A activity. In conclusion, our study revealed that GLN had multiple effects on the expression and activities of UGT1A isoforms, providing a basis for a better understanding of interactions between GLN and other drugs.

Glycyrrhetinic acid might increase the nephrotoxicity of bakuchiol by inhibiting cytochrome P450 isoenzymes

Background

Licorice, a popular traditional Chinese medicine (TCM), is widely used to moderate the effects (detoxification) of other herbs in TCM and often combined with Fructus Psoraleae. However, the classical TCM book states that Fructus Psoraleae is incompatible with licorice; the mechanism underlying this incompatibility has not been identified. Glycyrrhetinic acid (GA), the active metabolite of licorice, may increase the toxicity of bakuchiol (BAK), the main chemical ingredient in Psoralea corylifolia, by inhibiting its detoxification enzymes CYP450s.

Methods

The effect of concomitant GA administration on BAK-induced nephrotoxicity was investigated, and the metabolic interaction between BAK and GA was further studied in vitro and in vivo. The cytotoxicity was assessed using an MTT assay in a co-culture model of HK-2 cell and human liver microsomes (HLMs). The effect of GA on the metabolism of BAK, and on the activities of CYP isoforms were investigated in HLMs. The toxicokinetics and tissue exposure of BAK as well as the renal and hepatic functional markers were measured after the administration of a single oral dose in rats.

Results

In vitro studies showed that the metabolic detoxification of BAK was significantly reduced by GA, and BAK was toxic to HK-2 cells, as indicated by 25∼40% decreases in viability when combined with GA. Further investigation revealed that GA significantly inhibited the metabolism of BAK in HLMs in a dose-dependent manner. GA strongly inhibits CYP3A4 and weakly inhibits CYP2C9 and CYP1A2; these CYP isoforms are involved in the metabolism of BAK. In vivo experiment found that a single oral dose of BAK combined with GA or in the presence of 1-aminobenzotriazole (ABT), altered the toxicokinetics of BAK in rats, increased the internal exposure, suppressed the elimination of BAK prototype, and therefore may have enhanced the renal toxicity.

Conclusion

The present study demonstrated that GA inhibits CYP isoforms and subsequently may increase the nephrotoxicity of BAK, which underlie one of the possible mechanisms responsible for the incompatibility of Licorice with Fructus Psoraleae.

Development of an LC-MS/MS method for the quantitation of deoxyglycychloxazol in rat plasma and its application in pharmacokinetic study

Deoxyglycychloxazol (TY501) is a glycyrrhetinic acid derivative which exhibits high anti-inflammatory activity and reduced pseudoaldosteronism compared to glycyrrhetinic acid. In this study, a sensitive and rapid liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was established for the quantitation of TY501 in rat plasma. Plasma samples were treated by precipitating protein with methanol and supernatants were separated by a Symmetry C₈ column with the mobile phase consisting of methanol and 10 mM ammonium formate (containing 0.1% of formic acid) (90:10, v/v). The selected reaction monitoring (SRM) transitions were performed at m/z 647.4→191.2 for TY501 and m/z 473.3→143.3 for astragaloside aglycone (IS) in the positive ion mode with atmospheric pressure chemical ionization (APCI) source. Calibration curve was linear over the concentration range of 5–5000 ng/mL. The lower limit of quantification was 5 ng/mL. The mean recovery was over 88%. The intra- and inter-day precisions were lower than 6.0% and 12.8%, respectively, and the accuracy was within ±1.3%. TY501 was stable under usual storage conditions and handling procedure. The validated method has been successfully applied to a pharmacokinetic study after oral administration of TY501 to rats at a dosage of 10 mg/kg.

Immune adjuvant effect of Juzentaihoto, a Japanese traditional herbal medicine, on tumor vaccine therapy in a mouse model

Japanese traditional herbal medicine (Kampo) have been used to improve the general physical condition after surgery and to mitigate the side effects of radiation and chemotherapy in tumor patients. Juzentaihoto (JTT) consists of ten medical herbs, and is also called Shi-Quan-Da-Bu-Tang in Chinese herbal medicine. Among Kampo medicines, JTT has especially gained attention as a biological response modifier. Currently, clinical trials of various tumor vaccine therapies are being performed world-wide. However, tumor antigens that are inoculated as vaccines do not have high immunogenicity; thus, it is difficult to obtain an effective therapeutic effect. Thus, it is necessary to develop a tumor vaccine adjuvant that is more potent and very safe. In the present study, we examined the efficacy of JTT as an oral adjuvant when given together with tumor vaccines. As a result, JTT enhanced the phagocytic ability of OVA antigen and the presentation ability of OVA antigen in dendritic cells in vitro. Furthermore, tumor growth was markedly decreased, and the survival period was significantly prolonged in mice inoculated with mouse lymphoma, which is expressed with tumor model antigen. In conclusion, these findings suggest that JTT can be used with tumor vaccines as an immune adjuvant.

Effects of simvaglyzin and atorvaglyzin on the expression of 3-hydroxy-3-methyl-glutaryl-CoA reductase in rat liver

Activity and levels of protein and mRNA of 3-hydroxy-3-methyl-glutaryl-CoA reductase were estimated in rat liver after the administration of atorvastatin and simvastatin and their complexes with glycyrrhizic acid (atorvaglyzin and simvaglyzin). The amount of 3-hydroxy-3-methyl-glutaryl-CoA reductase protein in rats decreased by 13 and 25% (p<0.05) 24 h after treatment with atorvaglyzin and simvaglyzin, respectively. Activity of this enzyme decreased by 46% in rats treated with atorvaglyzin. The amount of messenger RNA in these groups significantly increased as compared to control group (untreated animals).

Pharmacokinetic study in mice of galphimine-A, an anxiolytic compound from Galphimia glauca

The aim of this study was to obtain pharmacokinetic data for the anxiolytic compound galphimine-A (G–A) from Galphimia glauca. G–A is the most abundant anxiolytic compound in this plant, while Galphimine-E (G–E) is the most abundant galphimine, but inactive. G–E was transformed chemically into G–A. The pharmacokinetic study was carried out in ICR mice, which were orally administered a single 200 mg/kg dose of G–A. Samples of blood and brain were taken at different times after administration of G–A. Previously, we established the validation of methods for determining the concentration of G–A. The G–A was detected in plasma 5 min after oral administration, and its concentration reached 2.47 μg/mL. Data from concentration-time curves allowed us to establish the main pharmacokinetic parameters in two models: one- and/or two-compartment. C_max values were 3.33 and 3.42 μg/mL respectively, likewise AUC_{0→1440 min} were 1,951.58 and 1,824.95 μg/mL·min. The G–A in brain tissue was noted to cross the blood-brain barrier, reaching C_max 2.74 μg/mL, T_max 81.6 min, and then drop gradually to 0.32 μg/mL detected at 24 h. The presence of G–A in brain tissue, confirmed that this anxiolytic compound can access the target organ and acts directly on the CNS.

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.

Ursolic acid in cancer prevention and treatment: molecular targets, pharmacokinetics and clinical studies

Discovery of bioactive molecules and elucidation of their molecular mechanisms open up an enormous opportunity for the development of improved therapy for different inflammatory diseases, including cancer. Triterpenoids isolated several decades ago from various medicinal plants now seem to have a prominent role in the prevention and therapy of a variety of ailments and some have already entered Phase I clinical trials. One such important and highly investigated pentacyclic triterpenoid, ursolic acid has attracted great attention of late for its potential as a chemopreventive and chemotherapeutic agent in various types of cancer. Ursolic acid has been shown to target multiple proinflammatory transcription factors, cell cycle proteins, growth factors, kinases, cytokines, chemokines, adhesion molecules, and inflammatory enzymes. These targets can potentially mediate the chemopreventive and therapeutic effects of ursolic acid by inhibiting the initiation, promotion and metastasis of cancer. This review not only summarizes the diverse molecular targets of ursolic acid, but also provides an insight into the various preclinical and clinical studies that have been performed in the last decade with this promising triterpenoid.

Determination of maslinic acid, a pentacyclic triterpene from olives, in rat plasma by high-performance liquid chromatography

Maslinic acid, a pentacyclic triterpene from olives, has been reported to exert beneficial effects on health, including anticarcinogenic activity. Despite its importance, little is known about its bioavailability in both humans and animals. A fundamental step for this evaluation consisted of measuring this compound in blood. Therefore, a simple high-performance liquid chromatography (HPLC) method with diode array detection has been developed. Maslinic acid contained in plasma was extracted twice using ethyl acetate. After centrifugation, the organic fraction was evaporated to dryness and the residue was reconstituted with methanol/water (75:25, v/v) and analyzed by HPLC. The method was validated by obtaining a linear correlation (r(2) = 0.999) and an average recovery of 99%. Precision expressed as the coefficient of variation ranged from 1.23 to 9.06%. The oral administration of maslinic acid (50 mg/kg) to rats and its subsequent detection in plasma showed that the method is suitable for absorption, distribution, and metabolism studies.

Enhanced transdermal delivery of 18β-glycyrrhetic acid via elastic vesicles: in vitro and in vivo evaluation

OBJECTIVE

The aim of this work was to develop an elastic vesicular formulation to enhance the skin permeation of a poorly water-soluble 18β-glycyrrhetic acid (GA) and treat dermatitis.

METHODS

Elastic vesicles of GA were prepared by the film method with high pressure homogenizer and characterized by storage stability. In vitro permeation studies were carried on rat skin using Franz diffusion cell. In vivo skin deposition of GA was studied using HPLC assay. Chronic allergic contact dermatitis model was built to evaluate pharmacodynamic of GA elastic vesicles.

RESULTS

The GA elastic vesicles developed have high flexibility and the storage stability was at least for 6 months at 4°C and for 4 months at 25°C. In vitro cumulative penetration of GA from elastic vesicles within 8 hours was 5.3-fold and 23.2-fold higher than that of conventional liposomes and saturated solution, respectively. After non-occlusive application to mice ears in vivo, skin deposition of GA increased immediately and reached the C(max) at 3 h (1.95 ± 0.32 µg/cm²) and still detected, even after 16 hours GA removed. In vivo anti-inflammatory activity study, GA elastic vesicles showed significant reduction in ear thickness and mass (25.52% and 49.23%) (P < 0.05). The suppressive activity was comparable to that of positive control group (Triamcinolone Acetonide and Econazole Nitrate cream in market), while few side effects were observed in present model.

CONCLUSION

The results suggested that of GA elastic vesicular was safe and effective in treatment of contact dermatitis by transdermal administration.

Biological analysis of herbal medicines used for the treatment of liver diseases

Herbal medicines have been used to treat liver disorders for thousands of years in the East and have now become a promising therapy internationally for pathological liver conditions. Biological analysis of hepatoprotective herbs is an important issue from the pharmacokinetic perspective in developing new therapeutic managements for liver disease. The biological analysis focuses on the pretreatment methods, separation and quantification of herbal medicines in biological samples. We have compiled and discuss the biological analytical method of six herbal medicines for liver protection containing Silybum marianum(silymarin), Glycyrrhiza glabra, Scutellaria baicalensis, Schisandra chinensis, Salvia miltiorrhiza and Astragalus membranaceus. This review provides a convenient reference for researchers to reduce time-consuming method optimization.

Gas phase isomeric differentiation of oleanolic and ursolic acids associated with heptakis-(2,6-di-O-methyl)-beta-cyclodextrin by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

Oleanolic acid (OA) and ursolic acid (UA) are isomeric triterpenoid compounds with similar pharmaceutical properties. Usually, modern chromatographic and electrophoretic methods are widely utilized to differentiate these two compounds. Compared with mass spectrometric (MS) methods, these modern separation methods are both time- and sample-consuming. Herein, we present a new method for structural differentiation of OA and UA by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with the association of heptakis-(2,6-di-O-methyl)-beta-cyclodextrin (DM-beta-CD). Exact MS and tandem MS (MS/MS) data showed that there is no perceptible difference between OA and UA, as well as their beta-cyclodextrin and gamma-cyclodextrin complexes. However, there is a remarkable difference in MS/MS spectra of DM-beta-CD complexes of OA and UA. The peak corresponding to the neutral loss of a formic acid and a water molecule could only be observed in the MS/MS spectrum of the complex of DM-beta-CD : OA. Molecular modeling calculations were also employed to further investigate the structural differences of DM-beta-CD : OA and DM-beta-CD : UA complexes. Therefore, by employing DM-beta-CD as a reference reagent, OA and UA could be differentiated with purely MS method.