Sensitive quantitative determination of oxymatrine and matrine in rat plasma by capillary electrophoresis with stacking induced by moving reaction boundary

Capillary electrophoresis fingerprints combined with Linear Quantitative Profiling Method to monitor the quality consistency and predict the antioxidant activity of Alkaloids of Sophora flavescens

Alkaloids of Sophora flavescens (ASF) has various pharmacological effects, and it is widely used in clinical practice. The aim of this research was to develop an environmentally friendly methodology that enables not only identification but also the quality consistency assessment of Alkaloids of Sophora flavescens. A background electrolyte composed of 50 mmol/L sodium tetraborate solution, 500 mmol/L boric acid and 1.2 mmol/L citric acid was used to conduct the fingerprint analysis coupled with quantitative determination of three components. Linear quantitative profiling method was used for comprehensive quality discrimination of the test samples from both qualitative and quantitative perspectives, and the 27 batches of samples were well differentiated. In addition, the fingerprint-efficacy relationship between chemical components and antioxidant activity in vitro was established using partial least squares regression model, which provided important medicinal efficacy information for quality control.

The synergy of diammonium glycyrrhizinate remarkably reduces the toxicity of oxymatrine in ICR mice

Most traditional Chinese medicine prescription dosages are imprecise. This study analyzes the toxicities and adverse effects of a combination the active ingredients of licorice and Kushen medicine: oxymatrine (OMT) and diammonium glycyrrhizinate (DG). The median lethal dose (LD₅₀) and mortality were analyzed in single-dose OMT (or DG) intraperitoneally injected mice with or without combination DG (or OMT). Body weight changes as well as levels of serum sodium and potassium, alanine transaminase (ALT), aspartate transaminase (AST), creatinine, and urea were measured in mice treated with a daily dose of OMT and/or DG for 14days. This study showed that the LD₅₀ of OMT for males and females were 347.44 and 429.15mg/kg, respectively. The LD₅₀ of DG were 525.10 and 997.26mg/kg for males and females, respectively. DG significantly decreased the mice LD₅₀-induced mortality of the OMT, however OMT did not succeed in reducing the LD₅₀-induced mortality rate of DG. The combination of OMT and DG obviously attenuated the changes of the body weight, serum sodium, and potassium induced by DG or OMT alone. These results suggested that toxicity and adverse effects of the OMT was significantly attenuated by DG. The OMT neutralized the adverse effects of the DG, but not the toxicity.

Pharmacokinetic study of 14-(3-methylbenzyl)matrine and 14-(4-methylbenzyl)matrine in rat plasma using liquid chromatography-tandem mass spectrometry

A rapid, sensitive and selective high-performance liquid chromatography-tandem mass spectrometric method (HPLC-MS) was developed and validated to determine the 14-(3-methylbenzyl)matrine (3MBM) and 14-(4-methylbenzyl)matrine (4MBM) levels in rat plasma in the present study. The analytes were separated using a C18 column (1.9 μm, 2.1 mm × 100 mm) equipped with a Security Guard C18 column (5 μm, 2.1 mm × 10 mm), followed by detection via triple-quadrupole mass spectrometry using an electrospray ionization (ESI) source. Sample pretreatment involved one-step protein precipitation with isopropanol:ethyl acetate (v/v, 25:75), and pseudoephedrine hydrochloride was used as an internal standard. The method was linear in the concentration range of 5-2000 ng/ml for both compounds. The intra-day and inter-day relative standard deviations (RSDs) were less than 15%, and all relative errors (REs) were within 15%. The proposed method enables the unambiguous identification and quantification of these two compounds in vivo. This study is the first to determine the 3MBM and 4MBM levels in rat plasma after oral administration of these compounds. These results provide a meaningful basis for evaluating the clinical applications of these medicines.

Enhanced fluorescence quenching in an acridine orange - alizarin red system through matrine and its analytical application

This study shows that alizarin red (AR) only slightly quenched fluorescence for acridine orange (AO) in an AR/AO mixed solution at pH=5-6. The reduced fluorescent signal was closely and linearly associated with the level of MT added to the system, which is the basis for a new quantitative MT assay method using the fluorescence quenching reaction in the AO-AR system. The results show that under optimal conditions, this method had a 14.9-43.5 mg L(-1) linear detection range with a 1.38 mg L(-1) detection limit and 1.24% precision. In addition, this method was used to determine the MT levels in the commercially available MT-containing pesticides and suppositories, which showed a 96.6-103% recovery. Therefore, this method has multiple advantages, including simple and fast operation, high accuracy and low cost. Moreover, herein, we investigated the underlying mechanism in-depth using an ultraviolet (UV) spectroscopic technique.

Analysis of brazilin and protosappanin B in sappan lignum by capillary zone electrophoresis with acid barrage stacking

A method was developed to determine brazilin and protosappanin B in natural products by CE after acid barrage stacking. The optimum conditions were as follows: a BGE of 20 mM sodium tetraborate (pH 9.2) containing 6% v/v of methanol, hydrodynamic injection (0.5 psi, 65 s) followed by hydrodynamic injection of 150 mM citric acid (pH 2.3; 0.5 psi, 22 s), and separated with +25 kV. Under these conditions, brazilin and protosappanin B were separated with a sample-to-sample time less than 13 min and detection limits of 0.28 μg/mL and 0.15 μg/mL, respectively. The applicability of the developed method was demonstrated by the detection of brazilin and protosappanin in methanol extract of sappan lignum.

Determination of oxymatrine and its active metabolite matrine in human plasma after administration of oxymatrine oral solution by high-performance liquid chromatography coupled with mass spectrometry

A rapid, sensitive and selective high-performance liquid chromatography mass spectrometric method has been developed and validated for the simultaneous determination of oxymatrine and its active metabolite matrine in human plasma after administration of oxymatrine oral solution. Analytes were extracted from the plasma by liquid-liquid extraction with chloroform. The chromatographic separation was accomplished on a Venusil C18 column (150 mm × 4.6 mm, 5 μm) protected by a C18 guard column (4.0 mm × 2.0 nm; Phenomenex, Torrance, CA, USA). Analytes were detected on a single quadruple mass spectrometer by selected ion monitoring mode via electrospray ionization source. The assay had a lower limit of quantification of 1.5 ng·mL(-1) for oxymatrine and 3 ng·mL(-1) for matrine in plasma. The calibration curves were linear in the measured range. The overall precision and accuracy for all concentrations of quality controls and standards were within ±15%. The proposed method enabled unambiguous identification and quantification of oxymatrine and its active metabolite matrine in vivo. The results provided a meaningful basis for evaluating the clinical applications of the oxymatrine oral solution.

Pharmacokinetic characterization of oxymatrine and matrine in rats after oral administration of radix Sophorae tonkinensis extract and oxymatrine by sensitive and robust UPLC-MS/MS method

The purpose of this study is to systematically investigate the pharmacokinetic (PK) behaviors of radix Sophorae tonkinensis (S. tonkinensis) using oxymatrine (OMT) and matrine (MT) as the target markers (2 mg/kg OMT and 1.3 mg/kg MT, oral administration). The PK characteristics in radix S. tonkinensis extracts were also compared with those of pure OMT. A fast ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed. OMT absorption was very fast, and no significant differences were observed (p>0.05) in tmax, CL, and t1/2 for both pure OMT and extracts. Cmax and AUC0→∞ of pure OMT were significantly higher than those of S. tonkinensis extracts (Cmax, 61.64±6.65 vs. 43.24±10.14 ng/mL; AUC, 9894.48±2234.99 vs. 4730.30±3503.8 min ng/mL) (p<0.05). However, the absolute OMT bioavailability of pure OMT was higher than that of the compound in radix S. tonkinensis extracts (6.79±2.52% vs. 1.87±2.66%). By contrast, the bioavailability of total alkaloids (OMT+MT) after pure OMT administration was 81.14±8.83%, similar to that of radix S. tonkinensis extracts (69.36±17.37%) (p>0.05). It was presumed that OMT absorption has no effect on the bioavailability of the two alkaloids. Other constituents in radix S. tonkinensis extracts can influence the transformation of OMT to MT, which directly leads to variations in the PK behavior of OMT. In addition, the protein binding of OMT and MT in plasma was very low (4.80%-8.95% for OMT, 5.10-10.55% for MT). In conclusion, OMT in radix S. tonkinensis extracts exhibits different PK behaviors with pure OMT through the transformation of OMT to MT due to other complex ingredients.

Urine Metabolite Profiling of Human Colorectal Cancer by Capillary Electrophoresis Mass Spectrometry Based on MRB

Aim. The study was to investigate the metabolic profile of urine metabolites and to elucidate their clinical significance in patients with colorectal cancer. Methods. Colorectal cancers from early stage and advanced stage were used in this study. Urine samples of colorectal cancer patients and healthy adults were collected and subjected to capillary electrophoresis mass spectrometry based on moving reaction boundary analysis. The metabolic data were analyzed by SPSS 17.0 to find urinary biomarkers for colorectal cancer. Results. The results indicated that the urine metabolic profiling of colorectal cancer patients had significant changes compared with the normal controls, and there were also differences between early stage and advanced colorectal cancer patients. Compared with the control group, the levels of isoleucine, valine, arginine, lactate acid and leucine increased (P < 0.05), but those of histidine, methionine, serine, aspartic acid, citric acid, succinate, and malic acid decreased in urine samples from colorectal cancer (P < 0.05). Furthermore, the levels of isoleucine and valine were lower in urine of patients with advanced colorectal cancer than those in early stage colorectal cancer (P < 0.05). Conclusion. The technique of capillary electrophoresis mass spectrometry based on MRB could reveal the significant metabolic alterations during progression of colorectal cancer, and the method is feasible and may be useful for the early diagnosis of colorectal cancer.

Effects of matrine and oxymatrine on catalytic activity of cytochrome p450s in rats

Matrine and oxymatrine are the major bioactive compounds extracted from the root of Sophora flavescens Ait, which have been widely used in traditional Chinese medicines. The objective of the study was to investigate the effects of matrine or oxymatrine on hepatic cytochrome P450 (CYP450) and the underlying molecular mechanisms. Matrine (15, 75 and 150 mg/kg) or oxymatrine (36, 180 and 360 mg/kg) was administered to rats for 14 days and the activities of CYP450 were measured by the quantification of the metabolites from multiple CYP450 probe substrates, using validated liquid chromatography coupled with liquid chromatography-tandem mass spectrometry detection (LC-MS/MS) and high-performance liquid chromatography methods. The mRNA and protein expression levels of CYPs were determined by quantitative real-time reverse-transcription polymerase chain reaction and Western blotting analysis respectively. Interactions between matrine or oxymatrine and human constitutive androstane (CAR), pregnane X receptor were evaluated by means of the reporter gene assay in CV-1 cells. Our study showed that matrine and oxymatrine significantly induced the activity and gene expression of CYP2B1 in a dose-dependent manner; matrine (150 mg/kg) slightly induced the mRNA and protein expression of CYP2E1 and mildly inhibited the mRNA and protein expression of CYP3A1 in rats. Matrine or oxymatrine could activate human CAR and induce the CYP2B reporter construct in CV-1 cells. These results reveal that matrine and oxymatrine can induce the activity and expression of CYP2B1/2 in rats, and the underlying mechanism may be related to the activation of CAR.

Matrine determination and pharmacokinetics in human plasma using LC/MS/MS

A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for the determination of matrine in human plasma extracted by isopropanol:ethyl acetate (v/v, 5:95). Rapid chromatographic separation was achieved in the mobile phase composition of 5-mM aqueous ammonium acetate and acetonitrile (v/v, 70:30) with a flow rate of 0.20ml/min. Detection was carried out using positive-ion electrospray tandem mass spectrometry on a Sciex API3000. The method was accurate, specific and sensitive for the analysis of matrine in human plasma in the concentration range of 5-2000ng/ml, when huperzine A was used as internal standard. The method facilitated a clinical pharmacokinetic study after oral administration of a single dose of matrine soft gelatin capsules (100, 200 and 400mg) in a three-period crossover design. Dose-related linear trends were observed for the AUC(0-t) and the C(max) of matrine. The t(1/2) and the T(max) of matrine were independent of the administered doses.

Contemporary sample stacking in CE

Sample stacking techniques remain an important tool for enhancement of the selectivity and sensitivity of analyses in contemporary CZE. This contribution reviews new knowledge on this topic published since 2006. It is organized according to the operational principles used, which include concentration adjustment, application of a pH step, MEKC and sweeping, and transient ITP. Techniques combining several of these principles and comparative studies are also included.

Pharmacokinetic study of matrine, oxymatrine and oxysophocarpine in rat plasma after oral administration of Sophora flavescens Ait. extract by liquid chromatography tandem mass spectrometry

A rapid, sensitive and selective high-performance liquid chromatography tandem mass spectrometric method (HPLC-MS) has been developed and validated for the simultaneous determination of matrine (MT), oxymatrine (OMT) and oxysophocarpine (OSP) in rat plasma after oral administration of Sophora flavescens Ait. extract using pseudoephedrine hydrochloride as an internal standard (I.S.). The three analytes were extracted from the plasma samples by liquid-liquid extraction with chloroform. The chromatographic separation was accomplished on a Kromasil C18 column (150 mm x 4.6 mm). Detection was performed on a single quadrupole mass spectrometer by selected ion monitoring (SIM) mode via electrospray ionization (ESI) source. The total run time was 12 min between injections. The assay had a lower limit of quantification of 1.0 ng/ml for MT, 2.0 ng/ml for OMT and 2.0 ng/ml for OSP using 200 microl of plasma. The calibration curves were linear in the measured range. The overall precision and accuracy for all concentrations of quality controls and standards was better than 15%. The proposed method enables unambiguous identification and quantification of MT, OMT and OSP in vivo. This was the first report on determination of the major quinolizidine alkaloids in rat plasma after oral administration of Sophora flavescens Ait. extract. The results provided a meaningful basis for evaluating the clinical applications of the herbal medicine.