Study on the pharmacokinetic profiles of corynoline and its potential interaction in traditional Chinese medicine formula Shuanghua Baihe tablets in rats by LC–MS/MS

Protoberberine alkaloids: A review of the gastroprotective effects, pharmacokinetics, and toxicity

BACKGROUND

Stomach diseases have become global health concerns. Protoberberine alkaloids (PBAs) are a group of quaternary isoquinoline alkaloids from abundant natural sources and have been shown to improve gastric disorders in preclinical and clinical studies. The finding that PBAs exhibit low oral bioavailability but potent pharmacological activity has attracted great interest.

PURPOSE

This review aims to provide a systematic review of the molecular mechanisms of PBAs in the treatment of gastric disorders and to discuss the current understanding of the pharmacokinetics and toxicity of PBAs.

METHODS

The articles related to PBAs were collected from the Web of Science, Pubmed, and China National Knowledge Infrastructure databases using relevant keywords. The collected articles were screened and categorized according to their research content to focus on the gastroprotective effects, pharmacokinetics, and toxicity of PBAs.

RESULTS

Based on the results of preclinical studies, PBAs have demonstrated therapeutic effects on chronic atrophic gastritis and gastric cancer by activating interleukin-4 (IL-4)/signal transducer and activator of transcription 6 (STAT6) pathway and suppressing transforming growth factor-beta 1 (TGF-β1)/phosphoinositide 3-kinase (PI3K), Janus kinase-2 (JAK2)/signal transducers and activators of transcription 3 (STAT3), and mitogen-activated protein kinase (MAPK) pathways. The major PBAs exhibit similar pharmacokinetic properties, including rapid absorption, slow elimination, and low bioavailability. Notably, the natural organ-targeting property of PBAs may account for the finding of their low blood levels and high pharmacological activity. PBAs interact with other compounds, including conventional drugs and natural products, by modulation of metabolic enzymes and transporters. The potential tissue toxicity of PBAs should be emphasized due to their high tissue accumulation.

CONCLUSION

This review highlights the gastroprotective effects, pharmacokinetics, and toxicity of PBAs and will contribute to the evaluation of drug properties and clinical translational studies of PBAs, accelerating their transfer from the laboratory to the bedside.

Corynoline inhibits esophageal squamous cell carcinoma growth via targeting Pim-3

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is an aggressive and deadly malignancy characterized by late-stage diagnosis, therapy resistance, and a poor 5-year survival rate. Finding novel therapeutic targets and their inhibitors for ESCC prevention and therapy is urgently needed.

METHODS

We investigated the proviral integration site for maloney murine leukemia virus 3 (Pim-3) protein levels using immunohistochemistry. Using Methyl Thiazolyl Tetrazolium and clone formation assay, we verified the function of Pim-3 in cell proliferation. The binding and inhibition of Pim-3 by corynoline were verified by computer docking, pull-down assay, cellular thermal shift assay, and kinase assay. Cell proliferation, Western blot, and a patient-derived xenograft tumor model were performed to elucidate the mechanism of corynoline inhibiting ESCC growth.

RESULTS

Pim-3 was highly expressed in ESCC and played an oncogenic role. The augmentation of Pim-3 enhanced cell proliferation and tumor development by phosphorylating mitogen-activated protein kinase 1 (MAPK1) at T185 and Y187. The deletion of Pim-3 induced apoptosis with upregulated cleaved caspase-9 and lower Bcl2 associated agonist of cell death (BAD) phosphorylation at S112. Additionally, binding assays demonstrated corynoline directly bound with Pim-3, inhibiting its activity, and suppressing ESCC growth.

CONCLUSIONS

Our findings suggest that Pim-3 promotes ESCC progression. Corynoline inhibits ESCC progression through targeting Pim-3.

Corynoline protects ang II-induced hypertensive heart failure by increasing PPARα and Inhibiting NF-κB pathway

Heart failure is a fairly common outcome of hypertension. Recent studies have highlighted the key role of the non-hemodynamic activity of angiotensin II (Ang II) in hypertensive heart failure via inducing cardiac inflammation. Drugs that disrupt Ang II-induced cardiac inflammation may have clinical utility in the treatment of hypertensive heart failure. A naturally occurring compound, corynoline, exhibit anti-inflammatory activities in other systems. C57BL/6 mice were injected with Ang II via a micro-osmotic pump for four weeks to develop hypertensive heart failure. The mice were treated with corynoline by gavage for two weeks. RNA-sequencing analysis was performed to explore the potential mechanism of corynoline. We found that corynoline could inhibit inflammation, myocardial fibrosis, and hypertrophy to prevent heart dysfunction, without the alteration of blood pressure. RNA-sequencing analysis indicates that the PPARα pathway is involved Ang II-induced cardiac fibrosis and cardiac remodeling. Corynoline reversed Ang II-induced PPARα inhibition both in vitro and in vivo. We further found that corynoline increases the interaction between PPARα and P65 to inhibit the NF-κB pro-inflammatory pathway in H9c2 cells. Our studies show that corynoline relieves Ang II-induced hypertensive heart failure by increasing the interaction between PPARα and P65 to inhibit the NF-κB pathway.

Transcriptome sequencing and metabolome analysis reveal the mechanism of Shuanghua Baihe Tablet in the treatment of oral mucositis

Oral mucositis (OM) caused by cancer therapy is the most common adverse reaction in the radiotherapy of head and neck tumors. In severe cases, it can lead to the interruption of treatment, which affects the control of the disease and the quality of life. Shuanghua Baihe Tablet (SBT) is a traditional Chinese medicine (TCM) formula, which is administerd to treat OM in China. It has been clinically effective for more than 30 years, but the underlying mechanism is not completely understood. With the development of multiple omics, it is possible to explore the mechanism of Chinese herbal compound prescriptions. Based on transcriptomics and metabolomics, we explored the underlying mechanism of SBT in the treatment of OM. An OM model of rats was established by 5-FU induction, and SBT was orally administered at dosages of 0.75 and 3 g·kg^-1·d^-1. In order to search for SBT targets and related metabolites, the dysregulated genes and metabolites were detected by transcriptomics and metabolomics. Immune related indicators such as interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) were detected by ELISA. Treg cell disorders was analyzed by flow cytometry. Our results showed that SBT significantly alleviated the symptoms of OM rats and the inflammatory infiltration of ulcer tissues. After SBT administration, inflammatory related metabolic pathways including linoleic acid metabolism, valine, leucine and isoleucine biosynthesis were significantly altered. Furthermore, the production of proinflammatory factors like IL-17 and TNF-α, were also dramatically reduced after SBT administration. Besides, the infiltration degree of Treg cells in the spleen of OM modeling rats was significantly improved by SBT administration, thus maintaining the immune balance of the body. The current study demonstrates that SBT regulates inoleic acid metabolism, glycerophospholipid metabolism and amino acid metabolism, and inhibits IL-17/TNF signal transduction to restore Treg and Th17 cell homeostasis in OM rats, thereby alleviating chemotherapy-induced OM.

Multiple component-pharmacokinetic studies on 10 bioactive constituents of Peiyuan Tongnao capsule using parallel reaction monitoring mode

Peiyuan Tongnao capsule (PTC) plays an important role in clinical application due to its excellent curative efficacy in the treatment of ischemic stroke and chronic cerebral circulation insufficiency. To standardize and rationalize the clinical application of PTC, a rapid and sensitive method based on ultra-high performance liquid chromatography/quadrupole-Orbitrap mass spectrometry with parallel reaction monitoring (PRM) mode was developed and validated for the pharmacokinetic (PK) study. Ten bioactive compounds (aucubin, salidroside, echinacoside, paeoniflorin, verbascoside, liquiritin, 2,3,5,4'-tetrahydroxy stilbene-2-O-β-d-glucoside, coumarin, glycyrrhizic acid, and emodin) were simultaneously determined in rat plasma. All calibration curves exhibited good linearity (r²  > 0.99). The lower limits of quantification were 0.082-13.291 ng mL^-1 . The intra- and inter-day precision was 0.54-12.36%, whereas the intra- and inter-day accuracy ranged from 100.45 to 114.00%. The mean extraction recoveries were 81.77-117.66%, and the average matrix effects (MEs) were 86.23-109.96%. The high extraction recoveries and acceptable MEs indicated that the pretreatment method was feasible. And the stability was acceptable under various storage conditions and processing procedures. The validated method was successfully applied to the multiple components-PK studies, which lay the foundation for further pharmacological and clinical research of PTC and may provide a reference for other traditional Chinese medicines.

Determination of Crizotinib in Mouse Tissues by LC-MS/MS and Its Application to a Tissue Distribution Study

Toxicity induced by crizotinib, a small-molecule tyrosine kinase inhibitor, is a significant clinical issue during treatment. A tissue distribution study is required to explore the organs affected by this molecule. In this study, a simple liquid chromatography tandem mass spectrometry method was developed and validated for the determination of crizotinib in various mouse tissues. Mouse tissue homogenates were processed by protein precipitation with methanol, and apatinib was chosen as the internal standard. The analytes were separated on a Phenomenex Kinetex C₁₈ (50 mm × 2.1 mm, 2.6 μm) column with gradient elution using methanol and 0.3% formic acid water solution. Tandem mass spectrometric detection was conducted using multiple reaction monitoring via an electrospray ionization source in the positive mode. The monitored ion transitions were m/z 450.1 ⟶ 260.2 for crizotinib and m/z 398.2 ⟶ 212.0 for apatinib. The problem of the severe carryover effect was successfully resolved. The method was validated and applied to a tissue distribution study of crizotinib in mice, which was reported for the first time. The results of the study showed that the main target organs of crizotinib were the lung, liver, and spleen, and a high concentration of crizotinib was found in the gastrointestinal tract. This study offers a reliable method for quantifying crizotinib and provides a basis for further research on crizotinib toxicity.

Network pharmacology strategy for revealing the pharmacological mechanism of pharmacokinetic target components of San-Ye-Tang-Zhi-Qing formula for the treatment of type 2 diabetes mellitus

ETHNOPHARMACOLOGICAL RELEVANCE

San-Ye-Tang-Zhi-Qing formula (SYTZQ) is an effective prescription for the treatment of pre-diabetes disorders of glycolipid metabolism in type 2 diabetes mellitus (T2DM). It consists of five Chinese herbs including Mori Folium, Nelumbinis Folium, Crataegi Folium, Salviae Miltiorrhizae Radix et Rhizoma and Paeoniae Radix Rubra.

AIM OF THE STUDY

This study was aimed to reveal the pharmacological mechanism of pharmacokinetic target components of SYTZQ for the treatment of T2DM.

MATERIALS AND METHODS

A rapid, precise and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to quantify simultaneously nuciferin, vitexin-4″-O-glucoside, vitexin-2″-O-rhamnoside, paeoniflorin and rosmarinic acid in rat plasma after oral administration of SYTZQ. The network pharmacology was used to analyze the effect of the compounds absorbed into the blood of SYTZQ on T2DM. The effects of paeoniflorin, nuciferine and rosmarinic acid on adipogenic differentiation were validated in vitro experiments.

RESULTS

The separation was performed on an ACQUITY UHPLC HSS T3 column (2.1 mm × 100 mm, 1.7 μm) using acetonitrile and 0.1% (v/v) formic acid in water as the mobile phase in gradient elution. The calibration curves of five analytes showed good linearity (r ≥ 0.9991) with the lower limits of quantification (LLOQ) between 0.3 and 5.0 ng/mL. The recoveries and matrix effects of five analytes ranged from 81.1% to 113%. The RSDs of inter-day and intra-day precision were all within 13.7%. The validated method was successfully applied to the pharmacokinetic study of five ingredients after oral administration of SYTZQ to rat. 39 major targets and 22 candidate pathways of five compounds absorbed into the blood of rats after administration of SYTZQ were identified and successfully constructed a compound-target-disease-pathway network. It was confirmed that paeniforin, nuciferine and rosmarinic acid could decrease the adipogenicity differentiation in vitro experiments.

CONCLUSIONS

The pharmacokinetic parameters indicated that the five components (nuciferin, vitexin-4″-O-glucoside, vitexin-2″-O-rhamnoside, paeoniflorin and rosmarinic acid) were absorbed and eliminated quickly in vivo. These five absorbed components were associated with 22 pathways, including insulin resistance, regulation of lipolysis in adipocytes, PI3k/AKT-, TNF-, cAMP- and cGMP-PKG-signaling pathway. Paeoniflorin, nuciferine and rosmarinic acid have the effect of inhibiting adipocyte differentiation. This study could provide more reference for quality control, and provide a firm basis for evaluating the clinical efficiency of SYTZQ.

Putative multiple reaction monitoring strategy for the comparative pharmacokinetics of postoral administration Renshen-Yuanzhi compatibility through liquid chromatography-tandem mass spectrometry

Background

Exploring the pharmacokinetic (PK) changes of various active components of single herbs and their combinations is necessary to elucidate the compatibility mechanism. However, the lack of chemical standards and low concentrations of multiple active ingredients in the biological matrix restrict PK studies.

Methods

A putative multiple reaction monitoring strategy based on liquid chromatography coupled with mass spectrometry (LC–MS) was developed to extend the PK scopes of quantification without resorting to the use of chemical standards. First, the compounds studied, including components with available reference standard (ARS) and components lacking reference standard (LRS), were preclassified to several groups according to their chemical structures. Herb decoctions were then subjected to ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry analysis with appropriate collision energy (CE) in MS² mode. Finally, multiple reaction monitoring transitions transformed from MS² of ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry were used for ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry to obtain the mass responses of LRS components. LRS components quantification was further performed by developing an assistive group-dependent semiquantitative method.

Results

The developed method was exemplified by the comparative PK process of single herbs Radix Ginseng (RG), Radix Polygala (RP), and their combinations (RG–RP). Significant changes in PK parameters were observed before and after combination.

Conclusion

Results indicated that Traditional Chinese Medicine combinations can produce synergistic effects and diminish possible toxic effects, thereby reflecting the advantages of compatibility. The proposed strategy can solve the quantitative problem of LRS and extend the scopes of PK studies.

Ultrahigh Performance Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry Method for Qualitative and Quantitative Analyses of Constituents of Corydalis bungeana Turcz Extract

In this study, the constituents of a Corydalis bungeana Turcz extract were qualitatively analyzed using gradient elution with a mobile phase of 0.2% acetic acid and acetonitrile. We obtained comprehensive insight into the constituents of C. bungeana Turcz extracts through the quantitative analysis of 14 compounds by comparison with authentic reference standards, and tentatively identified an additional 44 compounds through electrospray ionization mass spectrometry (ESI-MS) and tandem MS detection. The separation was successfully achieved using an Agilent SB-C₁₈ column (1.8 µm, 150 × 2.1 mm; Agilent, Santa, CA, USA). A tandem quadrupole spectrometer was operated in either full-scan mode or multiple reaction monitoring (MRM) for the qualitative and quantitative analyses of the constituents, respectively. Validation data (inter-day and intra-day combined) for accuracy and precision ranged from -4.80% to 4.73%, and 0.30% to 4.97%, respectively. An ultrahigh performance liquid chromatographic-ESI-tandem MS (UHPLC-ESI-MS/MS) method for qualitative of C. bungeana Turcz (C. bungeana) extract and the quantification of 14 alkaloids, namely, A-N, was developed and validated. Quantitative analysis involved gradient elution with a mobile phase of 0.1% acetic acid and methanol for 45 min. The separation was successfully achieved using a Waters SB-C₁₈ column (1.8 µm, 100 mm × 2.1 mm, Waters, Milford, Massachusetts, USA). The repeatability and stability of the method also met USFDA criteria with CV values lower than 5%. The limit of detection of the 14 alkaloids ranged from 9.74 to 13.00 ng/mL, whereas the linearities of the standard curves were between 0.9991 and 0.9995. In total, 15 commercial samples from 11 different sources were analyzed.

Metabolism-based herb-drug interaction of Corydalis Bungeanae Herba with berberine in vitro and in vivo in rats

Corynoline (CRL) and berberine (BER) are the major bioactive components found in traditional Chinese medicines Corydalis Bungeanae Herba (Corydalis bungeanae) and Coptidis Rhizoma, respectively. The two herbs serve as anti-inflammatory agents and are generally applied to many prescriptions. The aims of the study were to evaluate herb-drug interaction of C. bungeanae with BER and to investigate the mechanisms of the interaction action. Pre-treatment of BER caused reduction of plasma CRL in rats with increased formation of its three oxidative metabolites (M1-M3). Compared with the vehicle-treated group, the peak concentration and area under the concentration-time curve of CRL decreased by ~60% (given CRL) and ~50% (given extracts) in rats pre-treated with BER, respectively, along with 130 and 100% increases in apparent clearance. More M1-M3 were formed in liver microsomes of rats pretreated with BER (7 days) than in those pretreated with vehicle. Additionally, elevated activities of rCYPs2D2 and 1A2 (CYPs2D6 and 1A2) were observed in the BER-induced group. Up-regulated expression of hepatic rCYP2D2 (CYP2D6) was found in animals after 7 days of treatment of BER. The study illustrated that C. Bungeanae and BER produced metabolic herb-drug interaction and provided important information that combination of C. bungeanae with BER-containing herbal medicines may encounter the risk of decreased efficacy of CRL.

Metabolism and Bioactivation of Corynoline With Characterization of the Glutathione/Cysteine Conjugate and Evaluation of Its Hepatotoxicity in Mice

Corynoline (CRL), an isoquinoline alkaloid, is the major constituent derived from Corydalis bungeana Herba, which is a well-known Chinese herbal medicine widely used in many prescriptions. The purpose of this study was to comprehensively investigate the metabolism and bioactivation of CRL, and identify the CYP450 isoforms involved in reactive ortho-benzoquinone metabolites formation and evaluate its hepatotoxicity in mice. Here, high resolution and triple quadrupole mass spectrometry were used for studying the metabolism of CRL. Three metabolites (M1-M3) and four glutathione conjugates (M4-M7) of CRL ortho-benzoquinone reactive metabolite were found in vitro using rat and human liver microsomes supplemented with NADPH and glutathione. Four cysteine conjugates (M8-M11) were trapped in mice besides M1-M7. Using human recombinant CYP450 enzymes and chemical inhibitor method, we found that CYP3A4, CYP2C19, CYP2C9, and CYP2D6 were mainly involved in the bioactivation of CRL. Furthermore, CRL had no obvious hepatotoxicity and did not induce acute liver injuries in the experimental dosage (125-500 mg/kg) used in this study. However, phenomena of abnormal behaviors and low body temperature appeared in mice after drug administration, and three of them were dead. Tissue distribution study of CRL in mice showed that the main target organ of CRL was liver, then kidney, heart, and brain. CRL could traverse the blood-brain barrier, and have relative high concentration in brain. So, we surmise that toxicity effect of CRL on other organs may have occurred, and more attention should be paid on the traditional Chinese medicine contained CRL in clinic.

Liquid Chromatography-Tandem Mass Spectrometry Simultaneous Determination and Pharmacokinetic Study of Fourteen Alkaloid Components in Dog Plasma after Oral Administration of Corydalis bungeana Turcz Extract

A rapid and sensitive Ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous determination of fourteen alkaloids in beagle dog plasma after a single oral dose of the Corydalis bungeana Turcz (C. bungeana) extract selected bifendate as the internal standard (IS). The plasma samples were preprocessed by liquid-liquid extraction (LLE) with aether before separation on an Agilent SB-C₁₈ column (1.8 µm, 150 × 2.1 mm) using a gradient elution program. The mobile phase consists of 0.2% acetic acid and acetonitrile at the flow rate of 0.3 mL/min. In the positive ion mode, the analytes were detected by multiple reaction monitoring (MRM). The results indicated that calibration curves for fourteen analytes have good linearity (R² = 0.9904). The lower limits of quantification (LLOQ) of fourteen alkaloids and IS were all over 4.87 ng/mL and the matrix effects ranged from 94.08% to 102.76%. The mean extraction recoveries of Quality control samples at low (LQC), medium (MQC) and high (HQC) and IS were all more than 78.03%. The intra- and inter-day precision (R.S.D.%) also met the criterion, at the same time the deviation of assay accuracies (R.E) ranged from −13.70% to 14.40%. The T_max values of fourteen alkaloids were no more than 1 h. The range of C_max was from 74.16 ± 8.71 to 2256 ± 255.9 ng/mL. The assay was validated in the light of the regulatory bioanalytical guidelines and proved acceptable, which was successfully applied to a pharmacokinetic study of these compounds in beagle dogs after oral administration of Corydalis bungeana Turcz extract.

Randomized, Double-Blind, Placebo-Controlled Trial of Shuanghua Baihe Tablets to Prevent Oral Mucositis in Patients With Nasopharyngeal Cancer Undergoing Chemoradiation Therapy

PURPOSE

Oral mucositis is a common unpreventable complication associated with chemoradiation therapy. Shuanghua Baihe tablets have been approved by the Chinese Food and Drug Administration for treating recurrent oral mucosa ulceration. This study assessed whether Shuanghua Baihe tablets could prevent oral mucositis during chemoradiation therapy for locally advanced nasopharyngeal carcinoma.

METHODS AND MATERIALS

This multicenter, randomized, double-blind, placebo-controlled trial was conducted at 11 hospitals in China between January 22, 2014, and September 21, 2015. Eligible patients (N=240, 18-70 years old) with pathologically diagnosed locally advanced nasopharyngeal carcinoma were randomly assigned (computer-block randomization; 1:1) to receive Shuanghua Baihe tablets or a placebo (4 tablets, 3 times a day, for 7 weeks) at the initiation of chemoradiation therapy. Administration of Shuanghua Baihe tablets could be ended if grade 3 or higher oral mucositis developed and patients were unwilling to continue taking the drug. The primary endpoints were oral mucositis incidence and latency.

RESULTS

The incidence of oral mucositis during this study was significantly lower in the Shuanghua Baihe group (85.0%; 95% confidence interval [CI], 78.6%-91.4%) than in the placebo group (96.6%; 95% CI, 93.4%-99.9%; P=.0028). The median latency period was 28 days in the Shuanghua Baihe group and 14 days in the placebo group (hazard ratio, 0.17; 95% CI, 0.12-0.23; P<.0001). Compared with placebo, Shuanghua Baihe tablets significantly reduced the oral mucositis severity scores recorded by the investigators (Oral Mucositis Score, 24.0 [range, 0.0-67.8] vs 57.5 [range, 0.0-98.0]; P<.0001), full-time nurses (Oral Assessment Guide score, 462.0 [range, 392.0-664.7] vs 520.4 [range, 392.0-714.0]; P<.0001), and patients (score for soreness of mouth and throat, 4.0 [range, 0-10] vs 6.0 [range, 0-10]; P<.0001). No serious adverse events were observed, and the incidence of mild or moderate gastrointestinal adverse events associated with Shuanghua Baihe tablets was 3.3%. The short-term response rate was similar in patients receiving Shuanghua Baihe tablets and those receiving placebo during chemoradiation therapy during this study.

CONCLUSIONS

Shuanghua Baihe tablets reduced the occurrence, latency, and severity of oral mucositis in patients with nasopharyngeal cancer during chemoradiation therapy treatment.

Recent advances in pharmacokinetics approach for herbal medicine

Traditional Chinese Medicine (TCM), an indispensable part of herbal medicine, has been used for treating many diseases and/or symptoms for thousands of years.

Simultaneous determination of corynoline and acetylcorynoline in human urine by LC-MS/MS and its application to a urinary excretion study

Corynoline and acetycorynoline, the major active components derived from Corydalis bungeana Herba, showed multiple pharmacological activities. However, quantification of the two compounds in human urine has not been reported. A simple liquid chromatography with tandem mass spectrometry method for the simultaneous determination of corynoline and acetycorynoline in human urine has been developed and fully validated. The analytes were extracted from urine samples by simple liquid-liquid extraction. Chromatographic separation was achieved on a Hedera ODS-2C18 column with the mobile phase of water (containing 0.5% formic acid) and acetonitrile (28:72, v/v) at a flow rate of 0.4mL/min. A tandem mass spectrometric detection was conducted using multiple reaction monitoring via an electrospray ionization source in positive mode. The monitored ion transitions were m/z 368.1→289.1 for corynoline, m/z 410.2→289.2 for acetycorynoline and m/z 380.2→243.2 for donepezil (internal standard), respectively. The calibration curves were linear (correlation coefficients>0.9970) over the concentration ranges of 3.0-3000pg/mL for corynoline and 3.0-1000pg/mL for acetycorynoline. The established method was highly sensitive with the lower limit of quantification (LLOQ) of 3.0pg/mL for both analytes. The intra- and inter-day precision was lower than 10% in terms of relative standard deviation for the low, medium, and high quality control samples, and lower than 16% for the LLOQ samples of the analytes. The accuracy was within ±10% in terms of relative error for both analytes. The method was successfully applied to a urinary excretion study after oral administration of the Chinese medicine formula Shuanghua Baihe tablets in healthy volunteers. The urinary excretion profiles of corynoline and acetycorynoline in human were first reported. The results of this study suggest that renal excretion was not the main excretion pathway of corynoline and acetycorynoline in humans.

Highly sensitive method for simultaneous determination of nine alkaloids of Shuanghua Baihe tablets in human plasma by LC-MS/MS and its application

Shuanghua Baihe tablets (SBT) is a traditional Chinese medicinal formula which has been used to treat recurrent aphthous stomatitis for many years. To study the pharmacokinetic profiles of berberine, epiberberine, coptisine, palmatine, jatrorrhizine, magnoflorine, berberrubine, corynoline and acetylcorynoline in human after administration of SBT, a sensitive liquid chromatography-tandem mass spectrometry method was developed and fully validated for the simultaneous quantification of these nine alkaloids in human plasma. After protein precipitation, the nine alkaloids in human plasma sample was separated on a Hanbon C18 (150mm×2.1mm, 5μm) column with gradient elution using methanol and 0.5% formic acid water solution, and detected by a triple quadrupole mass spectrometer with an electrospray ionization source. It is a challenge to design different calibration ranges for different analytes in a bioanalytical method for simultaneous determination of multi-analytes in bio-samples. To ensure that each alkaloid in the plasma was determined accurately by the simultaneous quantitation method, the upper limits of quantification for the nine alkaloids were designed at 100, 300, 800, 1800 and 5000pg/mL, respectively, according to the maximum plasma concentration value of each alkaloid obtained from the pilot pharmacokinetic study. The lower limit of quantification was 15pg/mL for berberine, epiberberine, coptisine, magnoflorine, berberrubine, corynoline and acetylcorynoline, while for palmatine and jatrorrhizine it was 1.5pg/mL. This method was successfully applied to investigate the pharmacokinetic profiles of the nine alkaloids in healthy Chinese volunteers after a single oral administration of SBT.

Pharmacokinetics and safety of the multiple constituents of Shuanghua Baihe tablets in healthy subjects

It is the first clinical study to investigate the pharmacokinetics and safety of the multiple constituents of Shuanghua Baihe tablets in humans by LC-MS/MS.