A rapid and sensitive UFLC-MS/MS method for the simultaneous determination of gentiopicroside and swertiamarin in rat plasma and its application in pharmacokinetics

Characterization of the Chemical Constituents in Radix gentianae by Ultra-High Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry

Radix gentianae (RG) is a traditional Chinese medicine used for the treatment of acute and chronic hepatitis in clinic. However, the chemical profile of RG is still unconfirmed, which hindered the progress of pharmacological study and clinical application. In this study, ultra-high performance liquid chromatography together with quadrupole time-of-flight mass spectrometry techniques were employed to separate and characterize the chemical constituents in RG. Under the optimized conditions, a total of 60 compounds were rapidly identified or tentatively characterized. Results indicated that iridoid glucosides, flavonoids, organic acids, amino acids, saccharides and nucleosides were major constituents in RG. It is concluded the established method can help to clarify the substance basis and provide useful information for ascertaining the bioactive constituents and action mechanism of RG.

Metabolite Profiling of Swertia cincta Extract in Rats and Pharmacokinetics Study of Three Bioactive Compounds Using UHPLC-MS/MS

Swertia cincta, a plant of the genus Swertia in Gentianceae, has "heat-clearing" and detoxifying effects that normalize the gallbladder function in the treatment of jaundice. Although numerous studies on Swertia cincta have been performed, the absorption and pharmacokinetic behaviors remain unclear. In this study, the compounds of Swertia cincta in serum, bile, feces, and urine of rats were analyzed using a ultra-high-performance liquid chromatography-tandem mass spectrometry. A total of 9 prototype components and 48 metabolites were detected in biological samples. Furthermore, we determined the main components absorbed in the blood of Swertia cincta and established a method for simultaneously determining these components (sweroside, swertiamarin, and gentiopicroside) in positive ionization mode within 6 min. The quantitative method was successfully applied for the multiple-component pharmacokinetic study of Swertia cincta.

Safety of a feed additive consisting of a tincture derived from the roots of Gentiana lutea L. (gentian tincture) for all animal species (FEFANA asbl)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety of a tincture derived from Gentiana lutea L. (gentian tincture). It is intended to be used as a sensory additive for all animal species. The product is a water/ethanol solution, with a dry matter content of approximately 4.3% and it contains on average 0.0836% polyphenols (of which 0.0463% are flavonoids and 0.0027% xanthones) and 0.0022% gentiopicroside. The additive is intended for use in complete feed or drinking water up to a maximum level of 50 mg tincture/kg for all animal species, except horses, for which the proposed use is 200 mg/kg in complete feed. In a previous assessment, due to the genotoxic potential identified in vitro for xanthones (gentisin and isogentisin) and gentiopicroside the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) could not conclude on the safety of the additive for long-living animals and on risks of genotoxicity and carcinogenicity for dermal exposure of unprotected users. The additive did not raise safety concern for short-living animals, consumers and the environment. The applicant has provided information in the form of literature to address the previously identified genotoxic activity of xanthones and gentiopicroside and the risk for the user. Considering that the literature identified provided no new evidence, the FEEDAP Panel reiterated that it is not in a position to conclude on the safety of the additive for long-living and reproductive animals. No conclusions could be drawn on the potential of the additive to be a dermal/eye irritant or a skin sensitiser. When handling the tincture, exposure of unprotected users to xanthones (gentisin and isogentisin) and gentiopicroside cannot be excluded. Therefore, to reduce the risk, the exposure of the users should be minimised.

Activated Carbon-Based Immunochromatographic Strip Test for the Rapid Qualitative Analysis of Swertiamarin and Sweroside

Background

Swertia japonica (S. japonica) is a medicinal plant that belongs to the Gentianaceae family. Several reports confirm the biological effects of the S. japonica extract. This plant is used mainly as a digestive stimulant, appetite stimulant, and gastrointestinal disease remedy in Japan. Secoiridoid glycosides are a group of compounds related to the beneficial effects of this plant.

Objective

We developed an immunochromatographic strip test for major secoiridoid glycosides, such as swertiamarin (SM) and sweroside (SS) detection.

Methods

We fabricated an immunoprobe using activated carbon as a reporter molecule and a monoclonal antibody against SM and SS (MAb D2) as a detection molecule. The test and control zones of the strip test contained SM-cBSA and Goat pAb anti-mouse IgM HRP conjugate, respectively. The immunoprobe reacted competitively with free SM and/or SS and immobilized SM-cBSA. The results were read and interpreted by the black spot intensity in the test zone.

Results

We succeeded in developing a strip test system with a detection limit (LOD) of 12.5 µg/mL. The selectivity and reliability evaluation revealed that the strip test is suitable for detecting SM and SS in S. japonica. The result was ready to be read in 30 min.

Conclusions

This method can be a useful tool for the screening of biologically active S. japonica samples for further preparation of traditional medicine.

Highlights

To the best of our knowledge, this is the first immunochromatographic strip test developed for the detection of SM and SS in S. japonica samples.

A monoclonal antibody-based indirect competitive enzyme-linked immunosorbent assay to quantify swertiamarin and related compounds in Swertia japonica Makino

INTRODUCTION

Swertia japonica Makino (S. japonica) has a long history of use as a folk medicine, and it is one of the three essential Japanese folk medicines. S.japonica has been reported to have various biological activities. The biologically active secoiridoid glycoside swertiamarin (SM) has been isolated from S. japonica. The efficacy of this plant is attributed to SM and related secoiridoid glycosides. To control the quality of S. japonica for medicinal use, a method for the determination of SM and other secoiridoid glycosides in the plant is needed.

OBJECTIVE

To produce an anti-SM monoclonal antibody (MAb) and develop an indirect competitive enzyme-linked immunosorbent assay (icELISA) for S. japonica standardisation and quality control.

METHODOLOGY

SM was conjugated to cationised bovine serum albumin (cBSA), and the SM-cBSA conjugate was used to immunise BALB/c mice. Splenocytes from the immunised mice were then fused with SP2/0 myeloma cells to produce hybridoma cells that expressed anti-SM MAb.

RESULTS

The developed icELISA was sufficiently sensitive and had a quantitative range of 0.78 to 12.5 μg/mL. Coefficients of variation below 10% indicated good repeatability. Recoveries in a spike and recovery assay ranged from 91.84% to 115.50%, which confirmed that the icELISA was accurate. The SM content measured using the icELISA was in agreement with the results of a high-performance liquid chromatography-ultraviolet (HPLC-UV) assay.

CONCLUSION

The icELISA is suitable for the high-throughput analysis of SM and other secoiridoid glycosides in S. japonica. The method is fast, economical, and reliable for S. japonica quality control.

Pharmacokinetics and metabolic profiles of swertiamarin in rats by liquid chromatography combined with electrospray ionization tandem mass spectrometry

Swertiamarin, a typical compound of secoiridiod glycosides with various pharmacological effects which is the major iridoid glicoside of Swertia. In this study, we have established a fast and sensitive LC-MS/MS method. The aim was to conduct pharmacokinetic studies of swertiamarin in vivo of rats. Gentiopicroside was used as internal standard and a C18 column was employed for the separation of analytes. The selected reaction monitoring transitions were m/z 375→177, 357.1→195 for swertiamarin and the internal standard, respectively, in a positive ion mode. The results showed that swertiamarin had a good linearity in the range of 2-8000 ng/mL (r ＞ 0.997) and its limit of detection (LLOD) was 0.5 ng/mL. The developed method subsequently successfully used in the pharmacokinetic study of swertiamarin in rats after oral administration (50, 100, and 150 mg/kg). We obtained a series of pharmacokinetic parameters, and the half-time of swertiamarin was 1 h, while the oral bioavailability was between 5.6-7.6%. Six metabolites of swertiamarin were identified based on accurate mass measurements of protonated molecules and their MS/MS spectrum by ultra-high-performance chromatography/tandem quadrupole time-of-flight mass spectrometry. Furthermore, metabolites were classified into three groups and the metabolic pathway of swertiamarin was proposed. The finding may help for the understanding of effectiveness and safety of swertiamarin.

Simultaneous determination of four secoiridoid and iridoid glycosides in rat plasma by ultra performance liquid chromatography-tandem mass spectrometry and its application to a comparative pharmacokinetic study

A simple, reliable and rapid ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous quantification of four secoiridoid (gentiopicroside, swertiamarin, sweroside) and iridoid glycosides (loganic acid), the bio-active ingredients in rat plasma. After liquid-liquid extraction, chromatographic separation was accomplished on a Shim-pack XR-ODS column with a mobile phase consisting of methanol and 0.1% formic acid in water. A triple quadrupole tandem mass spectrometry equipped with an electrospray ionization source was used as detector operating both in positive and negative ionization mode and operated by multiple-reaction monitoring scanning. The lower limits of quantitation were 0.25-30 ng/mL for all the analytes. Both intra-day and inter-day precision and accuracy of analytes were well within acceptance criteria (±15%). The mean extraction recoveries of analytes and internal standard (amygdalin) from rat plasma were all >71.4%. The validated method was successfully applied to a comparative pharmacokinetic study of four analytes in rat plasma between normal and arthritic rats after oral administration of Huo Luo Xiao Ling Dan and Gentiana macrophylla extract, respectively. Results showed significant differences in pharmacokinetic properties of the analytes among the different groups.