Structural elucidation of in vitro and in vivo metabolites of cryptotanshinone by HPLC–DAD–ESI–MSn

Effect of Co-Solvents, Modified Starch and Physical Parameters on the Solubility and Release Rate of Cryptotanshinone from Alcohologels

(1) Background: The aim of the work was to investigate the influence of selected physico-chemical factors on the solubility and release rate of CT (cryptotanshinone) in alcohologels. (2) Methods: The alcohologels of methylcellulose (MC), hydroksyethylcellulose (HEC), polyacrylic acid (PA) and polyacrylic acid crosspolymer (PACP) with CT were prepared and/or doped with native potato starch (SN) and modified citrate starches (SM2.5 and SM10). The analytical methods included evaluation of CT release profiles, Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and electrospray ionization mass spectrometry (ESI-MS), and scanning electron microscope (SEM) images were performed. (3) Results: The release and decomposition kinetics of CT in relation to the phosphate buffer solution (PBS) and methanol were observed. The amount of cryptotanshinone (CT) released into PBS was significantly lower (2.5%) compared to its release into methanol, where 22.5% of the CT was released into the model medium. The addition of SM2.5 to the alcohologel significantly increased the CT content to 70% in the alcohologel preparation containing NaOH (40%), and this enhanced stability was maintained for up to two months. The ATR-FTIR exhibited interactions between PA and 2-amino-2-methyl-1,3-propanediol (AMPD) as well as between PA and NaOH in case of the alcohologels. Moreover, it indicated the interaction between CT and NaOH. PXRD diffractograms confirmed the FTIR study. (4) Conclusions: The study observed the influence of a number of factors on the solubility and release rate of CT, as: alkalizers and their concentration, SM2.5 addition. The transition of CT in the presence of NaOH to the tanshinone V sodium (T-V sodium) form was suspected.

Pharmacokinetic Comparison of Nine Bioactive Compounds of Guanxinshutong Capsule in Normal and Acute Myocardial Infarction Rats

BACKGROUND AND OBJECTIVES

Guanxinshutong capsules (GXST) are usually used to treat acute myocardial infarction (AMI), and the clinical effect of GXST is significant. However, there have been only a few studies on the pharmacokinetics of GXST against AMI injury. The objective of this study was to investigate the pharmacokinetics of nine bioactive compounds of GXST in normal and AMI rats.

METHODS

In this work, a rat model of AMI was established by ligating the left anterior descending coronary artery. The pharmacokinetic parameters of nine bioactive compounds (gallic acid, danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B and salvianolic acid A, dihydrotanshinone I, cryptotanshinone, and tanshinone IIA) in the plasma of AMI and normal rats were compared under the same dose of GXST by a LC-MS/MS method. Then, we selected P-glycoprotein (P-gp) and some representative cytochrome P450 enzymes (CYPs) for molecular docking to further analyze the interaction between these compounds.

RESULTS

The pharmacokinetic studies showed that the area under the concentration-time curve (AUC) and maximum concentration (C_max) of phenolic acids were relatively large, while the half-life (T_½) of tanshinones was longer. Among the nine components, salvianolic acid B in AMI rats had the maximum area under the concentration-time curve (AUC_0-∞ = 1961.8 ng·h/mL), which showed a significant difference compared with normal rats (P < 0.05). Tanshinone IIA in AMI rats had the longest half-life (T_½ = 10.1 h), and it was markedly longer than that in normal rats (P < 0.01). In addition, compared with the normal group, the AUC, C_max, T_½ , and time to reach C_max (T_max) of gallic acid increased significantly in AMI rats (P < 0.05 or P < 0.01). For the molecular docking results, it was found that gallic acid may interact with CYP1A2, CYP2D6, and CYP2C9, while danshensu may interact with CYP2C9. Tanshinones may interact with CYP1A2, CYP2D6, CYP2C9, and P-gp.

CONCLUSIONS

The results suggest that the pathological injury caused by AMI has a significant impact on the pharmacokinetic characteristics of some active compounds in GXST, which are conducive to providing a reference and promoting rational clinical drug use.

A review of the biological activity and pharmacology of cryptotanshinone, an important active constituent in Danshen

Cryptotanshinone (IUPAC name: (R)-1,2,6,7,8,9-hexahydro-1,6,6-trimethyl-phenanthro(1,2-b)furan-10,11-dione), a biologically active constituent extracted from the roots and rhizomes of the plant Salvia miltiorrhiza, has been studied in depth as a medicinally active compound and shown to have efficacy in the treatment of numerous diseases and disorders. In this review, we describe in detail the current status of cryptotanshinone research, including findings relating to the structure, pharmacokinetics, pharmacological activity, and derivatives of this compound. Cryptotanshinoneh as a diverse range of pharmacological effects, including anti-cancer, anti-inflammatory, immune regulatory, neuroprotective, and anti-fibrosis activities. Studies on the molecular mechanisms underlying the activities of cryptotanshinone have established that the JAK2/STAT3, PI3K/AKT, NF-κB, AMPK, and cell cycle pathways are involved in the inhibitory and pro-apoptotic effects of cryptotanshinone on different tumor cell lines, these molecular pathways interact in a coordinated manner to inhibit cell proliferation, migration and invasion,and induce transformation, autophagy, necrosis, and cellular immunity. The anti-inflammatory mechanisms of cryptotanshinone have been found to be associated with the TLR4-MyD88/PI3K/Nrf2 and TLR4-MyD88/NF-κB/MAPK pathways, whereasthe Hedgehog, NF-κB, and Nrf-2/HO-1 pathways are regulated by cryptotanshinone to reduce organ fibrosis, and its inhibitory effects on the PI3K/AKT-eNOS pathway have been linked to neuroprotective effects. Given the potential medicinal utility of cryptotanshinone, further research is needed to verify the efficacy and safety of this compound in clinical use, evaluate its pharmacological activity, and identify molecular targets.

Identification of the Metabolites in Rat Urine after Oral Administration and Elucidation of the Metabolic Process of Naozhenning Granule Using LC-MS

Naozhenning (NZN) granule, a Chinese herbal formula, is widely used to treat craniocerebral trauma and promote functional recovery. In our previous study, the chemical components, as well as the serum metabolites in the male Sprague-Dawley rats of the NZN granule after oral administration were characterized. In this study, the urine metabolites in the male Sprague-Dawley rats were further investigated by ultrahigh-performance liquid chromatography-Q Exactive hybrid quadrupole-Orbitrap high-resolution accurate mass spectrometry. In order to identify the urine metabolites comprehensively, three sample preparation methods were used, including solid-phase extraction, protein precipitation method and solvent partition. Based on the accurate molecular weight and the fragmentation information from the MS spectra, a total of 76 urine metabolites were identified, which including 17 prototypes and 59 metabolites. The results showed that the detected urine metabolites were different for the different pretreatment methods, as some metabolites could only be detected in the particular pretreatment method. In addition, the metabolic processes of the components from NZN granule to the serum and urine were also elucidated and discussed. The results will provide useful information for further studying the relationship between the chemical components and pharmacological activity of NZN granule.

Charactering the metabolism of cryptotanshinone by human P450 enzymes and uridine diphosphate glucuronosyltransferases in vitro

Cryptotanshinone (CT) is the main active component in the root of Salvia miltiorrhiza Bunge (SMB) that displays antibacterial, anti-inflammatory and anticancer activities. In this study, we characterized phase I and phase II metabolism of CT in human liver microsomes in vitro and identified the metabolic enzymes (CYPs and UGTs) involved. The metabolites of CT generated by CYPs were detected using LC-MS/MS and the CYP subtypes involved in the metabolic reactions were identified using chemical inhibitors of CYP enzymes and recombinant human CYP enzymes (CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4). Glucuronidation of CT was also examined, and the UGT subtypes involved in the metabolic reactions were identified using recombinant human UGT enzymes (1A1, 1A3, 1A4, 1A5, 1A6, 1A7, 1A8, 1A9, 1A10, 2B4, 2B7, 2B15 and 2B17). After adding NADPH to the human liver microsomes incubation system, CT was transformed into 6 main dehydrogenation and hydroxylation metabolites. CYP2A6, CYP3A4 and CYP2C19 were the major contributors to the transformation of its hydroxylation metabolites. CYP2C19, CYP1A2 and CYP3A4 were the major contributors to the transformation of its hydrogenation metabolites in human liver microsomes. This study showed that the metabolites at m/z of 473 were mediated by UGT1A9 and that the metabolites at m/z of 489 were mediated by UGT2B7 and UGT2B4. CT was extensively metabolized by UGTs following metabolism by CYPs in the liver.

Comprehensive Identification of Guan-Xin-Shu-Tong Capsule via a Mass Defect and Fragment Filtering Approach by High Resolution Mass Spectrometry: In Vitro and In Vivo Study

The Guan-Xin-Shu-Tong capsule (GXSTC) is a well-known traditional Chinese medicine that is used for the treatment of coronary heart disease. Despite its common use in China, basic pharmacological research on its active components is limited. A comprehensive analytical method using quadrupole-time-of-flight mass spectrometry (Q-TOF/MS), specifically with the Triple TOF 5600 platform, was developed to characterize the compounds in the GXSTC powder itself (in vitro) as well as the active components in healthy and heart disease model rats after its oral administration (in vivo). The 5600 platform was operated in both positive and negative ion modes, before the raw data were processed using the extracted ion chromatography (EIC), mass defect filtering (MDF) and fragment filtering (FF) techniques. With the aid of reference compounds for retention time and fragment ion comparisons, 18 compounds were unambiguously identified in vitro. An additional 56 other compounds were tentatively characterized using the accurate quasi-molecular ion mass and Tandem mass spectrometry (MS/MS) fragmentation pattern strategies. Among them, 30 compounds were characterized based on the MDF and FF approaches. Normal rats in addition to hyperlipidemic (HL) and acute blood stasis (ABS) model rats were given a single oral dose of GXSTC solution for subsequent blood analysis at 1 and 2 h after administration. A total of 24 prototypecomponents and 20 metabolites derived from GXSTC were differentially detected across the three animal groups, including the absence of four phase II phenolic acid metabolites in the ABS group and the presence of three diterpenoid-related metabolites exclusive to the HL group. The use of reference compounds as well as the mass defect and fragment-filtering strategies were critical to identify GXSTC compounds in vitro and in vivo. This can be used for further quality control and pharmacological studies aimed at characterizing the active and potential beneficial compounds of this ancient medicine.

Cryptotanshinone inhibits lung tumor growth by increasing CD4+ T cell cytotoxicity through activation of the JAK2/STAT4 pathway

Cryptotanshinone is one of the fat-soluble phenanthrene quinone components. In vitro studies have shown that tanshinone compounds can inhibit the proliferation of various tumor cells and affect cell cycle distribution. The aim of the present study was to better understand the effect of cryptotanshinone on the inhibition of small cell lung cancer by cytotoxic cluster of differentiation (CD)4⁺ T cells through activation of the Janus kinase 2/signal transducer and activator of transcription 4 (JAK2/STAT4) pathway. The Cell Counting kit-8 assay and the lactate dehydrogenase assay were used to analyze the cell proliferation of H446 and CD4⁺ T cells, and the cell cytotoxicity of CD4⁺ and CD8⁺ T cells, respectively. JAK2 and STAT4 protein expression was measured by western blot analysis. Cryptotanshinone effectively inhibited the tumor growth of the H446 cells and the cell proliferation of the CD4⁺ T cells. Treatment with cryptotanshinone increased the cytotoxicity of the CD4⁺ T cells, but could not affect the cytotoxicity of the CD8⁺ T cells. Meanwhile, cryptotanshinone induced phosphorylated (p)-JAK2 and p-STAT4 protein expression in the CD4⁺ T cells. These results suggest that cryptotanshinone inhibits the cell growth of lung tumors by increasing CD4⁺ T cell toxicity through activation of the JAK2/STAT4 pathway.

Identification of the chemical constituents of Chinese medicine Yi-Xin-Shu capsule by molecular feature orientated precursor ion selection and tandem mass spectrometry structure elucidation

The incomplete identification of the chemical components of traditional Chinese medicinal formula has been one of the bottlenecks in the modernization of traditional Chinese medicine. Tandem mass spectrometry has been widely used for the identification of chemical substances. Current automatic tandem mass spectrometry acquisition, where precursor ions were selected according to their signal intensity, encounters a drawback in chemical substances identification when samples contain many overlapping signals. Compounds in minor or trace amounts could not be identified because most tandem mass spectrometry information was lost. Herein, a molecular feature orientated precursor ion selection and tandem mass spectrometry structure elucidation method for complex Chinese medicine chemical constituent analysis was developed. The precursor ions were selected according to their two-dimensional characteristics of retention times and mass-to-charge ratio ranges from herbal compounds, so that all precursor ions from herbal compounds were included and more minor chemical constituents in Chinese medicine were identified. Compared to the conventional automatic tandem mass spectrometry setups, the approach is novel and can overcome the drawback for chemical substances identification. As an example, 276 compounds from the Chinese Medicine of Yi-Xin-Shu capsule were identified.

Identification of absorbed constituents and metabolites in rat plasma after oral administration of Shen-Song-Yang-Xin using ultra-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry

In this study, a rapid and sensitive method by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, and Metabolynx(TM) software with mass defect filter technique was developed for screening and identification of the metabolites in rat plasma after oral administration of Shen-Song-Yang-Xin capsule (SSYX). A total of 92 SSYX-related xenobiotics were identified or characterized, including 45 prototypes and 47 metabolites. The results indicated that the absorbed constituents and metabolites mainly came from benzocyclooctadiene lignans, tanshinones, isoquinoline alkaloids and triterpenic acids, while phase I reactions (e.g. hydrogenation, hydroxylation, demethylation) and phase II reaction (glucuronidation) were the main metabolic pathways of these ingredients in SSYX. This is the first study on metabolic profiling of SSYX in rat plasma after oral administration. Furthermore, these findings provide useful information on the potential bioactive compounds, and enhance our understanding of the action mechanism of SSYX.

Coexisted components of Salvia miltiorrhiza enhance intestinal absorption of cryptotanshinone via inhibition of the intestinal P-gp

Cryptotanshinone, derived from the roots of Salvia miltiorrhiza Bge and Salvia przewalskii Maxim, is the major active component and possesses significant antibacterial, antidermatophytic, antioxidant, anti-inflammatory and anticancer activities. The objective of this study was to investigate the intestinal absorptive characteristics of cryptotanshinone as well as the absorptive behavior influenced by co-administration of the diterpenoid tanshinones and danxingfang using an in vitro everted rat gut sac model. The results showed a good linear correlation between cryptotanshinone of absorption and the incubation time from 10 to 70min. The concentration dependence showed that a non-linear correlation existed between the cryptotanshinone absorption and the concentration at 100 μg/ml. Coexisting diterpenoid tanshinones and danxingfang could significantly enhance the absorption of cryptotanshinone. Coexisting diterpenoid tanshinones and danxingfang, which influenced cryptotanshinone's absorption, manifested as similar to that of the P-glycoprotein inhibitor. The underlying mechanism of the improvement of oral bioavailability was proposed that coexisting diterpenoid tanshinones and danxingfang could decrease the efflux transport of cryptotanshinone by P-glycoprotein.

Regioselective glucuronidation of tanshinone iia after quinone reduction: identification of human UDP-glucuronosyltransferases, species differences, and interaction potential

We have previously identified that the predominant metabolic pathway for tanshinone IIa (TSA) in rat is the NAD(P)H:quinone oxidoreductase 1 (NQO1)-mediated quinone reduction and subsequent glucuronidation. The present study contributes to further research on its glucuronidation enzyme kinetics, the identification of human UDP-glucuronosyltransferase (UGT) isoforms, and the interaction potential with typical UGT substrates. A pair of regioisomers (M1 and M2) of reduced TSA glucuronides was found from human, rat, and mouse, whereas only M1 was found in dog liver S9 incubations. The overall glucuronidation clearance of TSA in human liver S9 was 11.8 +/- 0.8 microl/min/mg protein, 0.7-, 0.8-, and 3-fold of that in the mouse, rat, and dog, respectively. Using intrinsic clearance M2/M1 as a regioselective index, opposite regioselectivity was found between human (0.7) and mouse (1.3), whereas no significant regioselectivity was found in rat. In a sequential metabolism system, by applying human liver cytosol as an NQO1 donor combined with a screening panel of 12 recombinant human UGTs, multiple UGTs were found involved in the M1 formation, whereas only UGT1A9 and, to a very minor extent, UGT1A1 and UGT1A3 contributed to the M2 formation. Further enzyme kinetics, correlation, and chemical inhibition studies confirmed that UGT1A9 played a major role in both M1 and M2 formation. In addition, TSA presented a potent inhibitory effect on the glucuronidation of typical UGT1A9 substrates propofol and mycophenolic acid, with an IC(50) value of 8.4 +/- 1.8 and 8.9 +/- 1.9 microM, respectively. This study will help to guide future studies on characterizing the NQO1-mediated reduction and subsequent glucuronidation of other quinones.

Structural elucidation of metabolites of tanshinone I and its analogue dihydrotanshinone I in rats by HPLC-ESI-MSn

Tanshinone I and its analogue dihydrotanshinone I are the major active components isolated from Salvia miltiorrhiza Bunge and Salvia Przewalskii Maxim. These compounds have been found to possess significant antibacterial, anti-dermatophytic, antioxidant, anti-inflammatory and anticancer activities. Fifteen phase I metabolites and two phase II metabolites of tanshinone I and dihydrotanshinone I in rat bile were elucidated and identified by a sensitive HPLC-ESI-MS(n) method. The molecular structures of the metabolites are presented on the basis of the characteristics of their precursor ions, product ions and chromatographic retention times. The results indicate that the phase I metabolites are biotransformed through four main pathways: dehydrogenation, hydroxylation, furan ring cleavage and oxidation metabolism. Phase II metabolites were mainly identified as the sulfated conjugates which showed a characteristic neutral loss of 80 Da. The biotransformed pathways of tanshinone I and dihydrotanshinone I were proposed on the basis of the investigation.

Identification of the metabolites of ecabet bismuth in rat bile by liquid chromatography-electrospray ionization-tandem mass spectrometry

In the present study, a liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI- MS/MS) method was developed for the screening and the structural elucidation of the metabolites of ecabet bismuth in rat bile. Solid-phase extraction cartridges were used for sample pre-treatment and a gradient liquid chromatographic system composed of 10 mM ammonium acetate buffer and methanol was used for chromatographic separation on a Phenomenex Kromasil C(18) column. The triple quadrupole mass spectrometer was employed to thoroughly detect and acquire the detailed MS/MS spectra of ecabet and its metabolites. By comparing the chromatographic retention behaviors, as well as the changes in molecular weight and full-scan MS/MS spectra of the potential metabolites with those of the parent compound, two main metabolites were identified as glucuronide conjugate of carbonylated ecabet (7-oxo-ecabet) and glucuronide conjugate of ecabet. Both two metabolites have not been reported in the literatures. The metabolic pathways of ecabet in rat were also proposed in this paper.