Development and validation of a dried blood spots assay for metabolic profiling of ginsenosides using ultra-high performance liquid chromatography-mass spectrometry.

ETHNOPHARMACOLOGICAL RELEVANCE: Panax ginseng C.A. Meyer., a famous and valuable traditional Chinese medicine with thousand years of history for its healthcare and therapeutic effects. It is necessary and meaningful to study the pharmacokinetic behavior of ginsenosides in vivo as they are the most active components. Dried blood spots (DBS) are a mature and advanced blood collection method with meet the needs for the measurement of numerous analytes. AIM OF THE STUDY: This study aimed to explore the feasibility on DBS in the metabolic profile analysis of complex herbal products. MATERIALS AND METHODS: An ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) method was developed and validated for the determination of ginsenosides. The preparation of DBS samples was conducted by spiking the whole blood with analytes to obtain 20 µL of blood spots on Whatman 903 collection card. A punched dish of 10 mm in diameter was extracted with 70 % methanol aqueous solution, digoxin was used as an internal standard. Target compounds were separated on a Waters T3 column (2.1 × 100 mm, 1.8 µm) with acetonitrile and water (0.1 % formic acid) at a flow rate of 0.4 mL/min. RESULTS: The various ginsenosides showed good linearity in the range of 1-2000 ng/mL. The extraction recoveries and matrix effects of the target analytes were above 82.2%. The intra- and inter-batch accuracy and precision were within the limits of ≤15% for all tested concentrations. Moreover, the collected dried blood spot samples could be stably stored at room temperature for 14 days and 4 °C for 1 month without being affected. And it is delightful that the DBS-based analysis is compatible or even superior to the conventional protein precipitation in terms of sensitivity, linearity, and stability. In particular, the target analytes are stable in the DBS sampling under normal storing condition and the sensitivity for some trace metabolites of ginsenosides, such as 20(S)-Rg3, 20(R)-Rg3, F1, Rk1, Rg5, etc. increases 3-4 folds as evaluated by LLOQ. CONCLUSIONS: The established method was successfully applied to pharmacokinetic studies of ginseng extract in mice, this suggests a more feasible strategy for pharmacokinetic study of traditional and natural medicines both in animal tests and clinical trials.

Identification of metabolites in plasma related to different biological activities of Panax ginseng and American ginseng.

RATIONALE: Panax ginseng (PG) and American ginseng (AMG) are both medicinal plants of the Panax genus in the Acanthopanax family. Although PG and AMG have similar components of ginsenosides, there are many differences of their bioactivities. In this study, the biochemical mechanisms of different bioactivities of PG and AMG were explored by researching the differential metabolites in plasma after administration of each of PG and AMG. METHODS: In order to explore the material basis of differential bioactivities, two groups of mice were administrated orally with PG and AMG, and the method of metabolomics was used to identify the differential metabolites in plasma. Then network pharmacology was used based on the differential metabolites. Afterward, the metabolite-target-pathway network of PG and AMG was constructed; thus the pathways related to different bioactivities were analyzed. RESULTS: Through principal component analysis and orthogonal projections to latent structures discriminant analysis, there were 10 differential metabolites identified in the PG group and 8 differential metabolites identified in the AMG group. Based on network pharmacology, the differential metabolites were classified and related to differential bioactivities of PG and AMG. In the PG group, there were 6 metabolites related to aphrodisiac effect and exciting the nervous system, and 5 metabolites associated with raised blood pressure. In the AMG group, 5 metabolites were classified as having the effect of inhibiting the nervous system, and 6 metabolites were related to antihypertensive effect. CONCLUSIONS: This study explored the material basis of the differential biological activities between PG and AMG, which is significant for the research of PG and AMG use and to promote human health.

Determination of Dammar-20(22)E,24-Diene-3ß,6α,12ß-Triol in rat plasma by LC-MS/MS and its application in a pharmacokinetic study.

Dammar-20(22)E,24-Diene-3ß,6α,12ß-Triol (YNPT2), as one of the main pharmacological and active components of Panax ginseng, promotes ubiquitination and degradation of hypoxia inducible factor Ia through proteasome, which reduces the content of hypoxia inducible factor Ia in tumor cells. Therefore, it is widely used in tumor inhibition. A sensitive and specific bioanalytical method of liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the quantification of YNPT2 rat plasma has been developed. Buspirone was used as the internal standard (IS). A 50 µl aliquot of rat plasma sample was deproteinized by 150 µl methanol-acetonitrile (1:1,v:v), vortex-mixed for 1 min and centrifuged at 15,000 r/min for 10 min at 4 °C. Then, 120 µl of supernatant was pipetted out into the autosampler vials and analyzed by LC-MS/MS with 10 µl injection volume. Chromatographic separation was performed on an Agilent ZORBAX XDB-C18 column (2.1 × 50 mm, 3.5 µm) with mobile phases consisting of water containing 5 mM ammonium acetate (mobile phase A) and acetonitrile (mobile phase B) at a flow rate of 0.6 ml/min over a total run time of 4.0 min. YNPT2 and buspirone (IS) were detected and quantified using positive electrospray ionization in multiple reaction monitoring (MRM) mode with transitions of m/z 441.4 â†’ 109.1 for YNPT2 and m/z 386.3 â†’ 122.1 for IS. The linear range was 5-2000 ng/ml with the square regression coefficient (r2) of 0.9972, and the lower limit of quantification (LLOQ) was 5 ng/ml. The intra-day and inter-day precision deviations of YNPT2 ranged from 3.8 to 6.9% and 3.5-5.8%, and accuracy error ranged from -7.4-5.9% and -9.2-11.9%. The average extraction recovery of YNPT2 in rat plasma was between the range of 98.5%-102.7%. This method was successfully applied to study the pharmacokinetics of YNPT2 in rats after intragastric administration at a single dose of 10.0 mg/kg and after intravenous injection at a single dose of 2.0 mg/kg.

Determination of ginsenoside Rh3 in rat plasma by LC-MS/MS and its application to a pharmacokinetic study.

Ginsenoside Rh3 (GRh3) is a bacterial metabolite of ginsenoside Rg5, which is the main component of hot-processed ginseng. A simple, efficient and sensitive method was developed and validated for the determination of GRh3 in rat plasma by LC-tandem mass spectrometry. After protein precipitation with methanol/acetonitrile (1:1, vol/vol) using propranolol as the internal standard, the target analytes were separated on an XDB C18 column, with methanol containing 0.1% formic acid and water containing 0.1% formic acid used as mobile phases for gradient elution. Mass spectrometry was performed in electrospray ion source-positive ion mode and multiple reaction monitoring mode, monitoring the transitions m/z 622.5 → 425.5 and m/z 260.1 → 116.1 for GRh3 and internal standard, respectively. The concentration range of GRh3 was 20-20,000 ng/mL and the correlation coefficient (r2 ) was greater than 0.99. The accuracy error and relative standard deviation were below 15%. The extraction recovery and matrix effect were 74.2% to 78.7% and 96.9% to 108.4%, respectively. Under different conditions, GRh3 was stable in the range of 1.8%-8.7%. This method has been successfully applied to study the pharmacokinetics of GRh3 with an oral dose of 10.0 mg/kg and an intravenous dose of 2.0 mg/kg in rats, respectively. The absolute bioavailability of GRh3 was 37.6%.

Comparative pharmacokinetics study of six effective components between two dosage forms of Qixue-Shuangbu Prescription in rats by UPLC-MS/MS.

Qixue-Shuangbu Prescription (QSP) is an efficacious prescription for treating heart failure, myocardial ischemia and other diseases. It is composed of nine Chinese herbs. This study investigated and compared the pharmacokinetics of QSP in rats by UPLC-MS/MS between two dosage forms of traditional decoction (TD) and compound tincture (CT). Owing to the complexity of the chemicals in QSP, ginsenoside Rg1, ginsenoside Re, ferulic acid, astragaloside IV, rhein and calycosin were chosen for the pharmacokinetics study. The method established for detecting serum specimens was shown to have acceptable selectivity, linearity, lower limit of quantitation, precision, accuracy, recovery, matrix effect and stability. The peak concentration, AUC0-t and AUC0-∞ of ginsenoside Re, ginsenoside Rg1, ferulic acid and rhein were significantly increased after oral administration of CT (P < 0.05), the half-life of ferulic acid in the CT group was lower than that in the TD group (P < 0.05) and the half-life and AUC0-∞ of astragaloside IV in the CT group were significantly increased (P < 0.05), which revealed that wine-processing could influence the bioavailability and the elimination of these compounds. For better clinical efficacy, we suggest that the CT dosage form of QSP should be selected.

Pharmacokinetic studies of ginsenosides Rk1 and Rg5 in rats by UFLC-MS/MS.

A rapid ultra-fast liquid chromatography tandem mass spectrometry method was developed and validated to determine ginsenosides Rk1 and Rg5, a pair of isomers, in rat plasma, which was successfully applied to their pharmacokinetic studies. Two ginsenosides were given to male Sprague-Dawley rats via intragastrical and intravenous routes, respectively, and the impact of double bond position on the pharmacokinetic features of the two ginsenosides was elucidated in rats. Ginsenoside Rg3 was used as internal standard and ethyl acetate was applied to extract analytes and internal standard. Chromatographic separation was carried out on a reverse-phase UPLC HSS T3 column (100 × 2.1 mm, 1.8 µm). The flow rate was set to 0.4 ml/min. The fragmentation transition was m/z 765.4 → m/z 101.1 for two ginsenosides. The mobile phases were composed of 0.1% formic acid aqueous solution and acetonitrile. The linear range was 2-1,000 ng/ml for the two ginsenosides. Intra- and inter-day precisions were <11.67%, and accuracy fluctuated from -7.44 to 6.78%. The extraction recovery, matrix effect and stability were within acceptable levels. After treatment with ginsenosides Rk1 and Rg5, some differences were found in their pharmacokinetic profiles in rats. The maximum plasma drug concentration and the area under the plasma drug concentration-time curve of ginsenoside Rg5 were about 5 times bigger than those of ginsenoside Rk1 after oral administration, and 3 times higher after intravenous administration. The oral bioavailabilities of ginsenosides Rk1 and Rg5 were 0.67 and 0.97%, respectively. The results indicated that ∆20(22) -ginsenosides showed better pharmacokinetic features than ∆20(21) -ginsenosides with the same glycosylation.

Pharmacokinetics of ginsenosides following repeated oral administration of red ginseng extract significantly differ between species of experimental animals.

We aimed to investigate ginsenoside pharmacokinetics in mice and rats following the repeated oral administration of red ginseng extract (RGE) (2 g/kg/day for 7 days). In mouse plasma, seven protopanaxadiol (PPD)-type ginsenosides (20(S)-ginsenoside Rb1, Rb2, Rc, Rd, Rg3, 20(S)-compound K, and 20(S)-PPD) and one protopanaxatriol (PPT)-type 20(S)-ginsenoside Re were detected, whereas 20(S)-ginsenoside Rb1, Rb2, Rc, Rd, 20(S)-PPD, and 20(S)-PPT were detected in rat plasma. The tetra- or tri-glycosylated PPD-type ginsenosides Rb1, Rb2, Rc, and Rd, high content ginsenosides in RGE, showed high plasma exposure, a short absorption time (Tmax), and a long elimination time (T1/2) among the ginsenosides detected in both species. Among the deglycosylated metabolites existing in the feces, 20(S)-compound K and 20(S)-PPD in mice and 20(S)-PPD and 20(S)-PPT in rats were found in the plasma samples. In addition to the differences in the ginsenosides detected in mice and rats, the Tmax and T1/2 of 20(S)-PPD and 20(S)-PPT in rats were greater than those in mice, suggesting the species-dependent difference in the gut metabolism and absorption of ginsenosides in the pathway from 20(S)-ginsenoside Rd to 20(S)-PPD and from 20(S)-ginsenoside Re to 20(S)-PPT. In conclusion, the choice of animal model should be the subject of careful consideration when exploring the pharmacology of RGE with specific focus on the plasma profile of an individual ginsenoside.

UFLC-MS/MS Determination and Population Pharmacokinetic Study of Tanshinol, Ginsenoside Rb1 and Rg1 in Rat Plasma After Oral Administration of Compound Danshen Dripping Pills.

BACKGROUND AND OBJECTIVES: As a traditional Chinese Materia Medica (CMM), the Compound Danshen Dripping Pill (CDDP) is widely used for the treatments of cardiovascular diseases. In view of its undefined applicable population and dosage, a population pharmacokinetic (PPK) study is required. The objective of this study was to explore the feasibility of multi-component CMM PPK in rat plasma after oral administration of CDDP based on sparse sampling. METHODS: In this research, a simple, rapid and highly sensitive UFLC-MS/MS method for the simultaneous determination of tanshinol (TSL), ginsenoside Rb1 (GRb1) and ginsenoside Rg1 (GRg1) has been successfully developed in rat plasma. Moreover, the validated method has been applied to a PPK study of CDDP based on sparse data. We established the PPK models for these three main active constituents using a nonlinear mixed-effects model, taking into account of factors such as gender, age in weeks and weight. RESULTS: The PPK models of TSL and GRb1 were best described by a one-compartment model with linear elimination and first-order absorption. The model of GRg1 was best described by a two-compartment model with first-order absorption. Bootstrap validation and a visual predictive check confirmed the predictive ability, the model stability and the precision of the parameter estimates from these models. CONCLUSION: As a preliminary exploration toward the clinical population pharmacokinetic research, this study provides a reference for the population pharmacokinetic study of traditional CMM.

Different absorption and metabolism of ginsenosides after the administration of total ginsenosides and decoction of Panax ginseng.

RATIONALE: Panax ginseng C.A. Meyer (PG), which contains polysaccharides and ginsenosides as the major bioactive components, has been used to promote health and treat diseases for thousands of years in China. Total ginsenosides were extracted from a decoction of Panax ginseng (GD), which included both ginsenosides and polysaccharides, and dissolved in water to obtain a total ginsenosides aqueous solution (TGAS). To study their absorption and metabolism, the pharmacokinetics (PK) and metabolites of ginsenosides in vivo were investigated after the administration of GD and TGAS. METHODS: Rat and mice plasma samples were collected after the administration of GD and TGAS. Ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry was used with the UNIFI platform to identify metabolites in the plasma sample. The pharmacokinetic parameters were calculated using a noncompartmental method in the Drug and Statistics software package. RESULTS: Thirty ginsenoside metabolites were identified in mice plasma, of which only seven were found in the rat plasma after the administration of GD. The PK of ginsenosides Rb1 , Rc, and Rd were also determined after the oral administration of GD and TGAS and showed significant differences in the pharmacokinetic parameters. CONCLUSIONS: There was no difference in the biotransformation pathways after the oral administration of GD and TGAS, indicating that there was no influence of polysaccharides on the biotransformation of ginsenosides in vivo. However, the pharmacokinetic parameters were different after the administration of GD and TGAS, possibly because of the polysaccharides in GD. This study should be of significance in exploring the basis of PG bioactivities and lays the foundation for the further development of new drugs using PG.

Pharmacokinetic effects of ginsenoside Rg1 on aconitine, benzoylaconine and aconine by UHPLC-MS/MS.

Ginseng and aconite are well-known couplet medicinals. Ginsenoside Rg1 is the main active ingredient in ginseng, and aconitine (AC), benzoylaconine (BAC) and aconine (ACN) are three representative alkaloids in aconite, which belong to the diester alkaloids, monoester alkaloids and alkanolamine alkaloids respectively. The aim of this study was to investigate the pharmacokinetic effects of ginsenoside Rg1 on the three types of alkaloids and to provide evidences for their compatibility mechanism. In this study, the ginsenoside Rg1 was simultaneously intragastrically administered to rats with AC, BAC and ACN, respectively, and the rat plasma was collected at different time points. The plasma drug concentrations of the three types of alkaloids were determined by UHPLC-MS/MS, and the pharmacokinetic parameters were calculated. The results indicated that the peak concentration and area under the concentration-time curve of BAC were significantly increased (P < 0.05), those for AC were decreased (P < 0.05), and the values for ACN did not change after pretreatment with ginsenoside Rg1. It was inferred that ginsenoside Rg1 may affect the absorption and metabolism of AC and BAC and then change their pharmacokinetic parameters. Subsequently, their absorption and metabolism were further investigated using the Caco-2 cell monolayer and rat liver microsomes in vitro. The Caco-2 cell monolayer absorption assay indicated that ginsenoside Rg1 could promote the absorption of AC and BAC, and the rat liver microsomes metabolism assay indicated that ginsenoside Rg1 accelerated the metabolism of AC and did not affect the other two alkaloids. All of the results indicated that ginsenoside Rg1 may reduce the toxicity of aconite and improve its efficacy by promoting the absorption of BAC and accelerating the metabolism of AC. These results could provide evidence for the compatibility mechanism of the traditional Chinese herbal formula Shenfu Decoction.

Dose-dependent exposure profile and metabolic characterization of notoginsenoside R1 in rat plasma by ultra-fast liquid chromatography-electrospray ionization-tandem mass spectrometry.

Notoginsenoside R1 (NGR1 ), a diagnostic protopanaxatriol-type (ppt-type) saponin in Panax notoginseng, possesses potent biological activities including antithrombotic, anti-inflammatory, neuron protection and improvement of microcirculation, yet its pharmacokinetics and metabolic characterization as an individual compound remain unclear. The aim of this study was to investigate the exposure profile of NGR1 in rats after oral and intravenous administration and to explore the metabolic characterization of NGR1 . A simple and sensitive ultra-fast liquid chromatographic-tandem mass spectrometric method was developed and validated for the quantitative determination of NGR1 and its major metabolites, and for characterization of its metabolic profile in rat plasma. The blood samples were precipitated with methanol, quantified in a negative multiple reaction monitoring mode and analyzed within 6.0 min. Validation parameters (linearity, precision and accuracy, recovery and matrix effect, stability) were within acceptable ranges. After oral administration, NGR1 exhibited dose-independent exposure behaviors with t1/2 over 8.0 h and oral bioavailability of 0.25-0.29%. A total of seven metabolites were characterized, including two pairs of epimers, 20(R)-notoginsenoside R2 /20(S)-notoginsenoside R2 and 20(R)-ginsenoside Rh1 /20(S)-ginsenoside Rh1 , with the 20(R) form of saponins identified for the first time in rat plasma. Five deglycometabolites were quantitatively determined, among which 20(S)-notoginsenoside R2 , ginsenoside Rg1 , ginsenoside F1 and protopanaxatriol displayed relatively high exploration, which may partly explain the pharmacodynamic diversity of ginsenosides after oral dose.

Detection of 13 Ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, Compound K, 20(S)-Protopanaxadiol, and 20(S)-Protopanaxatriol) in Human Plasma and Application of the Analytical Method to Human Pharmacokinetic Studies Following Two Week-Repeated Administration of Red Ginseng Extract.

We aimed to develop a sensitive method for detecting 13 ginsenosides using liquid chromatography-tandem mass spectrometry and to apply this method to pharmacokinetic studies in human following repeated oral administration of red ginseng extract. The chromatograms of Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, compound K (CK), protopanaxadiol (PPD), and protopanaxatriol (PPT) in human plasma were well separated. The calibration curve range for 13 ginsenosides was 0.5-200 ng/mL and the lower limit of quantitation was 0.5 ng/mL for all ginsenosides. The inter- and intra-day accuracy, precision, and stability were less than 15%. Among the 13 ginsenosides tested, nine ginsenosides (Rb1, Rb2, Rc, Rd, Rg3, CK, Rh2, PPD, and PPT) were detected in the human plasma samples. The plasma concentrations of Rb1, Rb2, Rc, Rd, and Rg3 were correlated with the content in red ginseng extract; however, CK, Rh2, PPD, and PPT were detected although they are not present in red ginseng extract, suggesting the formation of these ginsenosides through the human metabolism. In conclusion, our analytical method could be effectively used to evaluate pharmacokinetic properties of ginsenosides, which would be useful for establishing the pharmacokinetic-pharmacodymic relationship of ginsenosides as well as ginsenoside metabolism in humans.

Validated LC-MS/MS method for simultaneous quantification of seven components of Naodesheng in rat serum after oral administration and its application to a pharmacokinetic study.

A simple, precise and reliable LC-MS/MS method was developed and validated for simultaneous quantification of vitexin, notoginsenoside R1, hydroxysafflor yellow A, ginsenoside Rd, puerarin, daidzein and senkyunolide I as components of Naodesheng (NDS) in rat serum. The Linearity ranges in rat serum were 0.045-4.5 µg/mL for vitexin, 0.0476-4.76 µg/mL for notoginsenoside R1, 0.0422-4.22 µg/mL for hydroxysafflor yellow A, 0.0426-4.26 µg/mL for ginsenoside Rd, 0.0436-4.36 µg/mL for puerarin, 0.026-2.6 µg/mL for daidzein, and 0.05-5 µg/mL for senkyunolide I, with the correlation coefficients greater than 0.99. The established method was validated in terms of intra- and inter-day precision and accuracy, recovery, matrix effect and stability. Furthermore, the method was successfully applied for pharmacokinetic study of these seven components in rat serum after oral administration of NDS.

Pharmacokinetics and bioavailability study of ginsenoside Rk1 in rat by liquid chromatography/electrospray ionization tandem mass spectrometry.

Ginsenoside Rk1 (Rk1) exhibited various potent biological activities. However, its pharmacokinetic profile in vivo remains unclear. In the present study, a simple and sensitive liquid chromatography tandem mass spectrometry method was developed and validated for determination of Rk1 in rat plasma and applied in a pharmacokinetic study. The sample was precipitated with acetonitrile and separated on a Zorbax Eclipse XDB C18 column (50 × 2.1 mm, 1.8 µm). The mobile phase was composed of 0.1% formic acid in water and acetonitrile at a flow rate of 0.4 mL/min. Rk1 and internal standard (ginsenoside Rg3) were quantitatively monitored with precursor-to-product ion transitions of m/z 765.4 → 441.5 and m/z 783.5 → 621.4, respectively. The assay was linear over the concentration range of 5-1000 ng/mL (r > 0.99) with the LLOQ of 5 ng/mL. Other parameters including intra- and inter-day precision and accuracy, extraction recovery and matrix effect were within the acceptable limits. The analyte was stable under the tested storage conditions. The validated method has been successfully applied to a pharmacokinetic study of Rk1 in rat plasma after intravenous (5 mg/kg) and oral (25 mg/kg, 50 mg/kg) administration. After oral administration, Rk1 could be detected in blood at 30 min and reached the highest concentration at 4.29~4.57 h. Our results demonstrated that Rk1 showed low clearance, moderate half-life (3.09-3.40 h) and low bioavailability (2.87-4.23%). The study will provide information for the further application of Rk1.

Comparative pharmacokinetics of nine major bioactive components in normal and ulcerative colitis rats after oral administration of Lizhong decoction extracts by UPLC-TQ-MS/MS.

Lizhong decoction (LZD), a classic formula, has been used to treat ulcerative colitis (UC) for thousands of years in clinical practice. However, the pharmacokinetic characteristics of its major bioactive components in rats under different physiological and pathological states are not clear. Thus, in this study, a rapid and sensitive analytical method, ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS/MS) method, was developed and applied to simultaneously determine glycyrrhizic acid, liquiritin, isoliquiritin, glycyrrhizin, isoliquiritigenin, 6-gingerol, ginsenoside Rg1, ginsenoside Rb1 and ginsenoside Re in normal and UC rats after oral administration of LZD extract. A Waters BEH C18 UPLC column was used for chromatographic separation, while acetonitrile and 0.1% formic acid were selected as mobile phase. The linearity of nine analytes was >0.9920. Inter- and intra-day accuracy was ≤ 11.4% and precision was from 1.1 to 12.7%. Additionally, stable and suitable extraction recoveries were also obtained. The established method was validated and found to be specific, accurate and precise for nine analytes. Furthermore, it was successfully applied to the pharmacokinetic investigation of nine major components after oral administration of LZD extracts to normal and model rats, respectively. The results showed that the pharmacokinetic parameters (Cmax , Tmax , AUC0-t , AUC0-∞ ) in the plasma of UC rats were significantly different from those of normal rats, which could provide a reference for the clinical application of LZD.

Simultaneous determination of three saponins in human plasma after oral administration of compound danshen dripping pills by LC-MS/MS and its application in a pharmacokinetic study.

As one of the main constituents of Compound Danshen Dripping Pills (CDDP), Panax notoginseng (PN) plays a pivotal role in the treatment of cardiovascular diseases. Numerous researches have proved that the dammarane type saponins including notoginsenoside R1 (NR1), ginsenoside Rg1 (GRg1) and ginsenoside Rb1 (GRb1) are the main bioactive components of PN in CDDP. An efficient, realiable and sensitive liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis method for simultaneously detecting NR1, GRg1 and GRb1 in human plasma was established and applied to the pharmacokinetics study of the three PN saponins after oral administration of CDDP. The human plasma samples were processed using acetonitrile and the target materials were separated on an Eclipse plus C18 column (100 × 4.6 mm, 3.5 µm) with a gradient mobile phase consisted of water (containing 0.1% formic acid) and methanol. Within the concentration ranges of 0.25-50 ng/mL, each calibration curve exhibited an excellent linear relationship (r>0.998). The precision deviations of intra-day and inter-day analysis were lower than 9.0%, and accuracy error (RE%) ranged between 1.5% and 10.5%. The average recoveries of analytes were >64.0%. The established method was successfully applied to determine the pharmacokinetics of the three saponins in human plasma. In addition to providing guidance for clinical safe medication, the experimental results also provided a valuable and reliable basis for further pharmacological studies of PN in the human body after oral administration of CDDP.

Quantification of Panax notoginseng saponins metabolites in rat plasma with in vivo gut microbiota-mediated biotransformation by HPLC-MS/MS.

Panax notoginseng saponins (PNS) are the major components of Panax notoginseng, with multiple pharmacological activities but poor oral bioavailability. PNS could be metabolized by gut microbiota in vitro, while the exact role of gut microbiota of PNS metabolism in vivo remains poorly understood. In this study, pseudo germ-free rat models were constructed by using broad-spectrum antibiotics to validate the gut microbiota-mediated transformation of PNS in vivo. Moreover, a high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) was developed for quantitative analysis of four metabolites of PNS, including ginsenoside F1 (GF1), ginsenoside Rh2 (GRh2), ginsenoside compound K (GCK) and protopanaxatriol (PPT). The results showed that the four metabolites could be detected in the control rat plasma, while they could not be determined in pseudo germ-free rat plasma. The results implied that PNS could not be biotransformed effectively when gut microbiota was disrupted. In conclusion, gut microbiota plays an important role in biotransformation of PNS into metabolites in vivo.

Study on the herb-herb interaction of Danqi Tongmai Tablet based on the pharmacokinetics of twelve notoginsenoides in acute myocardial ischemia and sham rats.

Danqi Tongmai tablet (DQTT), an innovative TCM formula under clinical trials, is composed of salvianolic acids (SA) and panax notoginsenosides (PNE) for the treatment of coronary heart disease and angina pectoris. However, the in vivo herb-herb interaction of DQTT remains unclear. In the present research, a rapid, reliable and sensitive method for quantitative analysis of multi-notoginsenoside in rat plasma based on ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-TQ/MS) was established and then applied to explore the herb-herb interaction mechanism of DQTT based on the pharmacokinetics in acute myocardial ischemia (AMI) and sham rats after oral administration of DQTT and PNE. Compared with sham rats after oral administration of PNE, the values of AUC0-t for Rf and Rb2 were significantly higher in DQTT group. Compared with AMI rats after oral PNE, AUC0-t for NR1, Rg1, Re, Rb1, Rd, Rg2, Rb2, NR2, Rh1, F1 and F2 were significantly increased after oral administration of DQTT. These results hinted that SA could improve the bioavailability of notoginsenosides in AMI rats, which provides scientific information for better understanding the herb-herb interaction mechanism and offers a reference for clinical administration of DQTT. Additionally, the presently developed methodology was simple, robust, accurate, precise, and would be useful for the pharmacokinetic studies for all kinds of notoginsenosides and other herbal saponins.

Pharmacokinetic Study of Compound K in Japanese Subjects After Ingestion of Panax ginseng Fermented by Lactobacillus paracasei A221 Reveals Significant Increase of Absorption into Blood.

Compound K (CK) is a metabolite of a saponin in Panax ginseng, formed from ginsenoside, a triterpenoid glycoside, by human intestinal bacteria. Lactobacillus paracasei A221 isolated from fermented food can hydrolyze (deglycosylate) the main ginsenoside, ginsenoside Rb1, and generate CK. However, the pharmacokinetics of L. paracasei A221 fermented ginseng (FG) and nonfermented ginseng (NFG) have not been investigated so far. The aim of this study was to investigate the pharmacokinetics of CK after oral administration of single doses of FG and NFG in healthy Japanese adults. An open-label, randomized, single-dose, two-period, crossover study was conducted in 12 Japanese healthy volunteers (five men and seven women, aged 40-60 years). All subjects were equally allocated into two groups and administered tablets containing FG or NFG. Until 24 h after the administration, blood samples were sequentially collected, plasma concentrations of CK were measured, and the pharmacokinetic parameters were calculated. We also expected restoration of decreased testosterone level as one of the beneficial effects of FG and measured plasma total testosterone concentrations in male volunteers. The means of Tmax, Cmax, and area under the concentration-time curve (AUC) were significantly different between the two groups. In the FG group, AUC0-12h (ng h/mL) and AUC0-24h (ng h/mL) were, respectively, 58.3- and 17.5-fold higher than those in the NFG group. Moreover, mean testosterone concentration in the FG group significantly increased 24 h after administration. These results showed that the main ginsenoside metabolite of ginseng, CK, produced by L. paracasei A221 has potential utility in health maintenance in healthy middle-aged and old Japanese adults.

Multiple circulating saponins from intravenous ShenMai inhibit OATP1Bs in vitro: potential joint precipitants of drug interactions.

ShenMai, an intravenous injection prepared from steamed Panax ginseng roots (Hongshen) and Ophiopogon japonicus roots (Maidong), is used as an add-on therapy for coronary artery disease and cancer; saponins are its bioactive constituents. Since many saponins inhibit human organic anion-transporting polypeptides (OATP)1B, this investigation determined the inhibition potencies of circulating ShenMai saponins on the transporters and the joint potential of these compounds for ShenMai-drug interaction. Circulating saponins and their pharmacokinetics were characterized in rats receiving a 30-min infusion of ShenMai at 10 mL/kg. Inhibition of human OATP1B1/1B3 and rat Oatp1b2 by the individual saponins was investigated in vitro; the compounds' joint inhibition was also assessed in vitro and the data was processed using the Chou-Talalay method. Plasma protein binding was assessed by equilibrium dialysis. Altogether, 49 saponins in ShenMai were characterized and graded into: 10-100 µmol/day (compound doses from ShenMai; 7 compounds), 1-10 µmol/day (17 compounds), and <1 µmol/day (25 compounds, including Maidong ophiopogonins). After dosing, circulating saponins were protopanaxadiol-type ginsenosides Rb1, Rb2, Rc, Rd, Ra1, Rg3, Ra2, and Ra3, protopanaxatriol-type ginsenosides Rg1, Re, Rg2, and Rf, and ginsenoside Ro. The protopanaxadiol-type ginsenosides exhibited maximum plasma concentrations of 2.1-46.6 µmol/L, plasma unbound fractions of 0.4-1.0% and terminal half-lives of 15.6-28.5 h (ginsenoside Rg3, 1.9 h), while the other ginsenosides exhibited 0.1-7.7 µmol/L, 20.8-99.2%, and 0.2-0.5 h, respectively. The protopanaxadiol-type ginsenosides, ginsenosides without any sugar attachment at C-20 (except ginsenoside Rf), and ginsenoside Ro inhibited OATP1B3 more potently (IC50, 0.2-3.5 µmol/L) than the other ginsenosides (≥22.6 µmol/L). Inhibition of OATP1B1 by ginsenosides was less potent than OATP1B3 inhibition. Ginsenosides Rb1, Rb2, Rc, Rd, Ro, Ra1, Re, and Rg2 likely contribute the major part of OATP1B3-mediated ShenMai-drug interaction potential, in an additive and time-related manner.