Pharmacokinetic-pharmacodynamic modeling analysis and anti-inflammatory effect of Wangbi capsule in the treatment of adjuvant-induced arthritis.

Clinically, Wangbi Capsule (WBC) is widely used in the treatment of Rheumatoid arthritis (RA) because of its remarkable therapeutic effect. To reveal the mechanism, a pharmacokinetic-pharmacodynamic (PK-PD) model was developed for the first time to assess the relationship between time-concentration (dose)-effect. Freund's Complete Adjuvant was used to induce the adjuvant-induced arthritis model. Multi-indices were used to evaluate the therapeutic effect and an S-Imax PK-PD model was established based on the concentrations of osthole, 5-O-methylvisamminoside, cimifugin, albiflorin, paeoniflorin and icariin and the levels of interleukin-1ß and prostaglandin E2 using a two-compartment PK model together with a PD model with an effect-site compartment. The results suggest that WBC can treat RA by regulating the levels of prostaglandin E2 and interleukin-1ß. For the PK-PD model, the parameters indicated that WBC had a large safety margin and all six bioactive ingredients of WBC have therapeutic effects on RA. Among them icariin, osthole and 5-O-methylvisamminoside may be the main effective substances. This study provided a scientific basis for further study of population pharmacokinetics / population pharmacodynamics (PPK/PPD), to develop a reasonable administration plan and improve individualized drug therapy.

Comparative pharmacokinetics and metabolites study of seven major bioactive components of Shaoyao-Gancao decoction in normal and polycystic ovary syndrome rats by ultra high pressure liquid chromatography with tandem mass spectrometry.

A simple and sensitive liquid chromatography with tandem mass spectrometry method was developed for simultaneous quantification of paeoniflorin, albiflorin, oxypaeoniflorin, liquiritin, liquiritigenin, glycyrrhetinic acid, and glycyrrhizin in rat plasma after oral administration of Shaoyao-Gancao decoction, which is traditionally used in the treatment of polycystic ovary syndrome. The plasma samples were pretreated with methanol as precipitant. The method exhibited good linearity (correlation coefficient (R2 ) > 0.99) with lower quantification limits of 0.595-4.69 ng/mL for all analytes. Intra- and interbatch precision, accuracy, recovery, and stability of the method were all within accepted criteria. The results showed that the pharmacokinetic behaviors of the seven compounds were altered in the pathological status of polycystic ovary syndrome. Furthermore, a total of 36 metabolites were structurally identified based on their accurate masses and fragment ions. The major metabolic pathway involves phase I metabolic reactions (such as hydroxylation), phase II metabolic reactions (such as sulfation and glucuronidation conjugation) as well as the combined multiple-step metabolism. This study is the first report on the pharmacokinetic and metabolic information of Shaoyao-Gancao decoction in both normal and model rats, which would provide scientific evidences for the bioactive chemical basis of herbal medicines and also promote the clinical application of Shaoyao-Gancao decoction for treating polycystic ovary syndrome.

Neuroprotective effect of Trichosanthes kirilowii cassia twig on cerebral ischemia-reperfusion injury in rats.

In this study, in-depth observation and investigation of blood-brain barrier permeability and neuroprotective effect of Trichosanthes kirilowii cassia twig particles on rats with cerebral ischemia-reperfusion injury were performed. Focal cerebral ischemia-reperfusion injury model was established by middle cerebral artery occlusion method, reperfusion was implemented 2 hours after ischemia; qualitative analysis and investigation of trichosanthes kirilowii cassia twig particles in plasma, brain tissue and cerebrospinal fluid in normal and middle cerebral artery occlusion (MCAO) rats were done by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS); changes in neurological deficits, cerebral infarction stereometry, blood-brain barrier permeability and histopathological changes of MCAO model rats were observed. Qualitative analysis by HPLC-MS/MS results showed that ingredients, paeoniflorin, albiflorin, liquiritin in Trichosanthes kirilowii cassia twig particles can reach the brain through the blood-brain barrier. In the model group, glycyrrhizin and glycyrrhizic acid can be detected in brain tissue or cerebrospinal fluid. In addition, Trichosanthes kirilowii cassia twig particles can significantly lower neurological deficits of rats in middle cerebral artery occlusion model, reduce the Evans blue penetration, contract infarct size, and reduce pathological tissue injury of cerebral ischemia reperfusion. The ingredients of Trichosanthes kirilowii cassia twig particles can reach the brain tissue through the blood-brain barrier and play a role in neuroprotection of rats with cerebral ischemia-reperfusion injury, which has important research significance and brings scientific experimental, theoretical basis for clinical drug use.

Simultaneous determination of paeonilactone A and paeonilactone B in rat plasma after oral administration of albiflorin by UPLC/TOF/MS following picolinoyl derivatization.

A new highly sensitive analytical method was developed to investigate the in vivo metabolism of albiflorin, one of the most principal components in traditional Chinese medicine. After hydrolyzation with sulfatase, the main metabolites paeonilactone A and paeonilactone B of paeoniflorin in rat plasma were successfully detected for the first time by liquid chromatography mass spectrometry following picolinoyl derivatization. Borneol was used as the internal standard compound to quantify paeonilactone A and paeonilactone B in rat plasma. Paeonilactone A and paeonilactone B show different pharmacokinetic behaviors. The maximum plasma concentration of paeonilactone A reached 36.4±5.6ng/mL at about 8h after oral administration of albiflorin at a dose of 5mg/kg, while the maximum plasma concentration of paeonilactone B reached 12.4±3.4ng/mL at about 2h. The total metabolic pathway of albiflorin in rats was proposed. Albiflorin was found to be metabolized to the sulfate of paeonilactone A and paeonilactone B which may be responsible for the biological effect of albiflorin. The new analytical method may help to elucidate the clinical efficacy of traditional Chinese formula containing albiflorin.

Simultaneous determination of ginsenoside Rb1, ginsenoside Rg1, paeoniflorin, albiflorin and oxypaeoniflorin in rat plasma by liquid chromatography-tandem mass spectrometry: Application to a pharmacokinetic study of wen-Yang-Huo-Xue soft capsule.

A simple and sensitive HPLC-MS/MS method was developed and fully validated for simultaneous determination of ginsenoside Rb1, ginsenoside Rg1, paeoniflorin, albiflorin and oxypaeoniflorin in rat plasma. Plasma samples were pretreated with protein precipitation using acetonitrile. The chromatographic separation was carried out on a C18 column with a gradient mobile phase consisting of acetonitrile and water (containing 0.1% formic acid). All analytes and digoxin (internal stand, IS) were quantitated through electrospray ionization in negative ion multiple reaction monitoring mode. All calibration curves exhibited good linearity (r > 0.9960) over a wide concentration range for all components. The intra-day and inter-day precisions (RSD) at three different levels were all <12.0% and the accuracies (RE) ranging from -6.1 to 6.2%. The extraction recoveries of the five compounds ranged from 89.2 to 97.1%. The validated method was successfully applied in a comparative pharmacokinetic study of Wen-Yang-Huo-Xue soft capsule (WYHXSC) in rats. Compared with single pure component, the exposure of the investigated components, except for oxypaeoniflorin, increased after oral administration of WYHXSC in rats, which suggested a synergistic effects between the herbs in the WYHXSC preparations.

Robust Translation of γ-Secretase Modulator Pharmacology across Preclinical Species and Human Subjects.

The amyloid-ß peptide (Aß)-in particular, the 42-amino acid form, Aß1-42-is thought to play a key role in the pathogenesis of Alzheimer's disease (AD). Thus, several therapeutic modalities aiming to inhibit Aß synthesis or increase the clearance of Aß have entered clinical trials, including γ-secretase inhibitors, anti-Aß antibodies, and amyloid-ß precursor protein cleaving enzyme inhibitors. A unique class of small molecules, γ-secretase modulators (GSMs), selectively reduce Aß1-42 production, and may also decrease Aß1-40 while simultaneously increasing one or more shorter Aß peptides, such as Aß1-38 and Aß1-37. GSMs are particularly attractive because they do not alter the total amount of Aß peptides produced by γ-secretase activity; they spare the processing of other γ-secretase substrates, such as Notch; and they do not cause accumulation of the potentially toxic processing intermediate, ß-C-terminal fragment. This report describes the translation of pharmacological activity across species for two novel GSMs, (S)-7-(4-fluorophenyl)-N2-(3-methoxy-4-(3-methyl-1H-1,2,4-triazol-1-yl)phenyl)-N4-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine-2,4-diamine (BMS-932481) and (S,Z)-17-(4-chloro-2-fluorophenyl)-34-(3-methyl-1H-1,2,4-triazol-1-yl)-16,17-dihydro-15H-4-oxa-2,9-diaza-1(2,4)-cyclopenta[d]pyrimidina-3(1,3)-benzenacyclononaphan-6-ene (BMS-986133). These GSMs are highly potent in vitro, exhibit dose- and time-dependent activity in vivo, and have consistent levels of pharmacological effect across rats, dogs, monkeys, and human subjects. In rats, the two GSMs exhibit similar pharmacokinetics/pharmacodynamics between the brain and cerebrospinal fluid. In all species, GSM treatment decreased Aß1-42 and Aß1-40 levels while increasing Aß1-38 and Aß1-37 by a corresponding amount. Thus, the GSM mechanism and central activity translate across preclinical species and humans, thereby validating this therapeutic modality for potential utility in AD.

Sensitive analysis and pharmacokinetic study of the isomers paeoniflorin and albiflorin after oral administration of Total Glucosides Of White Paeony Capsule in rats.

A sensitive and reliable method using liquid chromatography tandem mass spectrometry (LC-MS/MS) was established for the simultaneous assay of paeoniflorin and albiflorin in bio-samples of rats after liquid-liquid extraction with ethylacetate. For the first time, the developed method was validated and successfully applied to the pharmacokinetics study of paeoniflorin and albiflorin after oral administration of Total Glucosides Of White Paeony Capsule (TGP). Relative to the intravenous injection, the absolute bio-availabilities of paeoniflorin and albiflorin were 2.8 and 1.7%, while their excretion in feces was 43.06 and 40.87%, respectively. Both paeoniflorin and albiflorin showed dose-dependent exposure in plasma, with a half-life of approximately 1.8h. No significant differences were observed between a single equal dose of paeoniflorin or albiflorin and that of TGP for the pharmacokinetic parameters, including AUC, T1/2 and Cmax. Paeoniflorin and albiflorin were exposed at high levels in immune relevant organ/tissues, such as the spleen, thymus and bone, which could facilitate immuno-regulatory activities.

Comparisons of the pharmacokinetic profile of four bioactive components after oral administration of gan-sui-ban-xia decoction plus-minus gansui and gancao drug combination in normal rats.

Gan-Sui-Ban-Xia Decoction (GSBXD) was first presented by Zhang Zhongjing in the book Synopsis of Golden Chamber during the Han Dynasty period. The formula was then used for the treatment of persistent fluid retention with floating pulse in Traditional Chinese Medicine (TCM), which in modern medicine is known as malignant ascites. Here, a rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed for the determination of glycyrrhizinic acid, liquiritin, paeoniflorin, albiflorin after oral administration of GSBXD plus-minus Gansui and Gancao anti-drug combination to investigate the possible pharmacokinetic profile differences of different prescriptions with GSBXD in normal rats. The differences of pharmacokinetic parameters among groups were tested by the Student's t-test with p < 0.05 as the level of significance. Significant differences were found between the Gansui and Gancao anti-drug combination and other herbs in GSBXD on pharmacokinetic profile of glycyrrhizinic acid, liquiritin, paeoniflorin and albiflorin. The obtained knowledge might contribute to the rationality of the clinic use of GSBXD and also reveal the compatibility conditions of the Gansui and Gancao anti-drug combination.

Pharmacokinetic synergy from the taxane extract of Taxus chinensis improves the bioavailability of paclitaxel.

BACKGROUND: Taxus chinensis (Pilger) Rehd is widely distributed in China and the northern hemisphere, and the most popular medicinal component isolated from Taxus chinensis is paclitaxel (PTX), which has now become the first-line chemotherapeutic drug for breast cancer and ovarian cancer. Oral administration of pure PTX as a potential anti-cancer agent is compromised by low bioavailability. HYPOTHESIS/PURPOSE: In the clinical practice of traditional Chinese medicine, drug co-administration in the form of mixtures or formula could achieve pharmacokinetic/pharmacodynamic synergies. In this study, we aimed to investigate whether there exist any 'inherent' phytochemical synergy from Taxus chinensis extract that could improve PTX bioavailability. STUDY DESIGN: Pharmacokinetic study of PTX after oral administration of Taxus chinensis extracts or single PTX was performed. In addition, comparative cytotoxic studies were carried out on the MCF-7 breast cancer cell lines. METHODS: The plasma concentrations of PTX were determined using a validated high performance chromatography tandem mass spectrometry method. The cytotoxicity was compared using the MTT assay. RESULTS: Oral administration of taxane fractions isolated from Taxus chinensis (containing 17.2% PTX) could achieve remarkably higher blood concentration and systemic exposure of PTX in rats, while the retention of PTX was significantly improved. Further tissue distribution analysis revealed that the penetration of PTX into major tissues was drastically increased compared with that of single PTX. In addition, in MCF-7 cells, the co-existing components in taxane mixtures could strengthen the inhibitory effects of PTX on tumor cell proliferation. CONCLUSION: Together, these results support that administration of PTX in the form of taxane mixtures may become a novel approach to improve the poor bioavailability of PTX. Moreover, the inherent synergy from Taxus chinensis taxane extracts promises a novel strategy to strengthen PTX efficacy.

Pharmacokinetic comparisons by UPLC-MS/MS of isomer paeoniflorin and albiflorin after oral administration decoctions of single-herb Radix Paeoniae Alba and Zengmian Yiliu prescription to rats.

Zengmian Yiliu (ZMYL), a traditional Chinese formula, is designed to improve clinical efficacy and reduce adverse effects in combination with cisplatin in ovarian cancer chemotherapy. In ZMYL, Radix Paeoniae Alba (RPA, made from root of Paeonia lactiflora Pall.) acts as an adjunctive drug in cancer treatment by ameliorating side effects induced by radio- and chemotherapy. The pharmacokinetics differences between isomer albiflorin and paeoniflorin, the main components of RPA, after oral administration decoction of single-herb RPA and ZMYL were compared using a sensitive and accurate UPLC-MS/MS. The results indicate that there are statistically significant differences between the pharmacokinetic parameters: decreasing area under the plasma concentration-time curve (AUC), maximum concentration (Cmax ), elimination rate constant (Ke ) and increasing apparent volume of distribution (Vd ) and clearance (CL) for albiflorin, increasing distribution half-life (T1/2d ) and decreasing elimination half-life (T1/2e ), distribution rate constant (Kd ) and absorption rate constant (Ka ) for paeoniflorin in the ZMYL group compared with the single-herb RPA group. In comparison with albiflorin, the pharmacokinetic parameters of paeoniflorin included significantly increasing mean residence time (MRT) and Vd , decreasing CL and Ke in the single-herb RPA group and increasing MRT and T1/2d and decreasing CL, Ke and Kd in the ZMYL group. Both paeoniflorin and albiflorin are more likely, as the main active ingredients in RPA and ZMYL, to play a variety of pharmacological effects, and herb-herb interactions occur, resulting in different pharmacokinetics of albiflorin and paeoniflorin in RPA and ZMYL.

[Study on rational daily administration frequency of Fufang Biejia Ruangan tablet based on integrated serum pharmacologic and pharmacokinetic model].

To observe in vitro the effect of rat drug serum on the proliferation of HSC-T6 hepatic stellate cells in the pharmacokinetic model for determining peoniflorin in Fufang Biejia Ruangan tablet, in order to discover the rational daily administration frequency of Fufang Biejia Ruangan tablet. Fufang Biejia Ruangan tablet was orally administered to rats with different daily administration frequency. Their blood was collected from veins behind eye sockets at different time points before the administration and after the first administration, in order to determine the concentration of peoniflorin in blood plasma and the effect of rat drug serums on the proliferation of HSC-T6. A comprehensive analysis was made on the relationship between pharmacodynamics and pharmacokinetics to determine the rational daily administration frequency of Fufang Biejia Ruangan tablet. The results showed a good correlation between the inhibitory effect of Fufang Biejia Ruangan tablet-contained serum on HSC-T6 and the concentration of peoniflorin in blood. The two-time administration group showed higher pharmacologic and pharmacokinetic AUCs than one-time administration and three-time administration groups. In conclusion, Fufang Biejia Ruangan table is recommended to be taken twice a day for treating liver fibrosis in chronic hepatitis.

Simultaneous determination of five phenolic components and paeoniflorin in rat plasma by liquid chromatography-tandem mass spectrometry and pharmacokinetic study after oral administration of Cerebralcare granule(®).

A simple, sensitive and selective high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method was developed for simultaneous determination and pharmacokinetic study of six active components, protocatechuic acid, chlorogenic acid, caffeic acid, ferulic acid rosmarinic acid and paeoniflorin in rat plasma after oral administration of Cerebralcare granule(®) for the first time. The method involves a simple liquid-liquid extraction with ethyl acetate. The separation was performed on a Luna C18 column (2.0×100mm i.d., 3.0µm, particle, Phenomenex, USA) with gradient elution using a mobile phase composed of acetonitrile and water (containing 0.1% formic acid) at a flow rate of 0.2ml/min. Electrospray ionization (ESI) in negative ion mode and selective reaction monitoring (SRM) was used for the quantification of six active components and internal standard (IS, Chloroamphenicol). The method was linear for all analytes over investigated range with all correlation coefficients greater than 0.9914. The lower limits of quantification (LLOQ) were 1.0ng/ml for protocatechuic acid, 1.0ng/ml for chlorogenic acid, 1.0ng/ml for caffeic acid, 5.0ng/ml for ferulic acid, 1.5ng/ml for rosmarinic acid and 6.0ng/ml for paeoniflorin, respectively. The intra- and inter-day precisions (R.S.D.%) were less than 6.60% and 11.68%, and accuracy (RE %) between -3.26% and 1.13% (n=6). The developed method was applied for the first time to the pharmacokinetic study of protocatechuic acid, chlorogenic acid, caffeic acid, ferulic acid, rosmarinic acid and paeoniflorin in rat plasma after oral administration of Cerebralcare granule(®).

[In vitro transdermal delivery of the active fraction of xiangfusiwu decoction based on principal component analysis].

The objective of the present study was to establish a method based on principal component analysis (PCA) for the study of transdermal delivery of multiple components in Chinese medicine, and to choose the best penetration enhancers for the active fraction of Xiangfusiwu decoction (BW) with this method. Improved Franz diffusion cells with isolated rat abdomen skins were carried out to experiment on the transdermal delivery of six active components, including ferulic acid, paeoniflorin, albiflorin, protopine, tetrahydropalmatine and tetrahydrocolumbamine. The concentrations of these components were determined by LC-MS/MS, then the total factor scores of the concentrations at different times were calculated using PCA and were employed instead of the concentrations to compute the cumulative amounts and steady fluxes, the latter of which were considered as the indexes for optimizing penetration enhancers. The results showed that compared to the control group, the steady fluxes of the other groups increased significantly and furthermore, 4% azone with 1% propylene glycol manifested the best effect. The six components could penetrate through skin well under the action of penetration enhancers. The method established in this study has been proved to be suitable for the study of transdermal delivery of multiple components, and it provided a scientific basis for preparation research of Xiangfusiwu decoction and moreover, it could be a reference for Chinese medicine research.

[Experimental studies on pharmacokinetics of three components in Buyanghuanwu injection on base of total quantum statistical moment].

OBJECTIVE: To verify established the total quantum statistic moments model with astragaloside IV, paeoniflorin, tetramethylpyrazine in Buyanghuanwu injection, in order to establish a pharmacokinetic experimental method with multi-component traditional Chinese medicine (TCM) compound system. METHOD: The RP-HPLC was adopted, with the chromatographic column of C18, 4.6 mm x 250 mm, 5 microm. As for astragaloside IV, the ELSD detector was adopted with acetonitrile-water (35: 65) as the mobile phase at 1 mL x min(-1); the pressure of column was (15.0 +/- 0.408) MPa, the column temperature was 30 degrees C. Regarding paeoniflorin and tetramethylpyrazine, the detection of wavelengths was 254 nm, with acetonitrile-water (35:65) as the mobile phase at 1 mL x min(-1), the column pressure of (15.17 +/- 0.41) MPa. The pharmacokinetic parameters for single component were dealt with DAS and the total quantum statistical moment (TQSM) parameters were calculated using formulations. RESULT: All of the three components followed the two compartmental pharkacokinetic model (P < 0.01) in rats. Compared with the superimposed total concentration, each single component showed difference in parameters up to 10 000 times at most, whereas the RSD of TQSM parameters was 3.510%. The TQSM pharmacokinetic parameters of the three components in Buyanghuanwu injection showed that AUC(t), MRT(t), VRT(t), CL(t), V(t), were (119.8 +/- 27.20) g x min x L(-1), (210.0 +/- 54.49) min, (5.608 +/- 2.723) x 10(4) min2, (0.319 6 +/- 0.068 8) mL x min(-1) x kg(-1) and (64.12 +/- 8.243) mL x kg(-1), respectively, suggesting that the half-life time for the three components were (145.5 +/- 37.76) min and 95% of them were metabolized within 0-674. 2 min. CONCLUSION: The TQSM can be used to study pharmacokinetic parameters of multi-component TCM compound, because the method can characterize the pharmacokinetic regularity of quantum-time change in a multi-component system.

UHPLC-MS simultaneous determination and pharmacokinetic study of three aromatic acids and one monoterpene in rat plasma after oral administration of Shaofu Zhuyu decoction.

We developed a sensitive and rapid method for determination of ferulic acid, caffeic acid, vanillic acid, and paeoniflorin in rat plasma based on ultra high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The separation of the four compounds was carried out on an AcQuity UHPLC™ BEH C18 column using a mobile phase consisting of acetonitrile and water (containing 0.1% formic acid). Electrospray ionization in positive and negative ion mode and multiple reaction monitoring was used to identify and quantify active components. All calibration curves gave good linearity (r > 0.991) over the concentration range from 4.24-2875 ngmL(-1) for all components. The precision of the in vivo study was evaluated by intraday and interday assays and the percentages of RSD were all within 10.6%. The recovery ranged from 60.2 to 77.9%. The method was successfully applied to pharmacokinetic study of all three aromatic acids and one monoterpene in rat plasma. Furthermore, we compared the pharmacokinetics profile of the four compounds in normal and primary dysmenorrhea rats' plasma following oral administration of Shaofu Zhuyu decoction (SFZYD) and its ethanol supernatant extract (SFE).

Pharmacokinetic study of multiple active constituents after oral gavage of Guizhi decoction in rats using a LC-MS/MS method.

Guizhi decoction (GZD) is a classic traditional Chinese medicine formula, clinically used for the treatment of influenza, common cold, and other pyretic conditions. A sensitive, specific, and validated liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed to investigate the pharmacokinetic properties of cinnamic acid, hippuric acid, paeoniflorin, and glycyrrhetic acid in rat. After single dose oral administration of 7.9 g extract/kg body weight GZD in rats, plasma concentrations of cinnamic acid, hippuric acid, paeoniflorin, and glycyrrhetic acid were measured by LC-MS/MS. Pharmacokinetic parameters were calculated from the plasma concentration-time data. The values of AUC0-t, half-life (t 1/2), and C max were 7.2 ± 2.3 µg h/mL, 1.2 ± 0.3 h, and 9.2 ± 5.2 µg/mL for cinnamic acid, 53 ± 31 µg h/mL, 2.8 ± 2.0 h, and 17 ± 3 µg/mL for hippuric acid, 1.1 ± 0.5 µg h/mL, 1.9 ± 1.1 h, and 0.6 ± 0.3 µg/mL for paeoniflorin, and 11 ± 6 µg h/mL, 6.6 ± 2.5 h, and 0.9 ± 0.6 µg/mL for glycyrrhetic acid, respectively. The results would offer useful information for effective components of GZD in vivo.

[Multi-channel analysis and comparison on absorption difference between paeoniflorin and Paeonia lactiflora extracts].

OBJECTIVE: To compare the difference of the absorption difference between paeoniflorin monomer and Paeonia lactiflora extracts in rat intestinal canals by multi-channels. METHOD: The rat intestinal perfusion model was established. The intestinal perfusate, bile and plasma samples were collected, in combination of the intestinal enzymes incubation test and the partition coefficient determination, to conduct a multi-channel analysis and comparison on absorption difference between paeoniflorin and P. lactiflora extracts. RESULT: In the same concentration, permeability coefficient P(eff)* of paeoniflorin in the different intestinal segments of P. lactiflora extract higher than the monomer of paeoniflorin, especially in the jejunum and ileum intestinal segments (P < 0. 05). However, both paeoniflorin monomer and P. lactiflora extracts showed less P(eff)* in four intestinal segments, with the former ranging between 0. 209-0.290 and the latter 0.252-0.333. No paeoniflorin and its metabolin was determined in bile samples, plasma samples and intestinal enzymes incubation samples of paeoniflorin monomer and P. lactiflora extracts. CONCLUSION: Compared with the paeoniflorin monomer, P. lactiflora extract showed significantly increase in P(eff)*, which indicated that other ingredients in the extract can improve the absorption of paeoniflorin. However, due to the poor absorption of paeoniflorin, this effect fails to increase the concentration of paeoniflorin in bile and plasma within short period of time.

Food- and gender-dependent pharmacokinetics of paeoniflorin after oral administration with Samul-tang in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Samul-tang (Si-Wu-tang in Chinese, Shimotsu-to in Japanese), widely used in eastern Asia, is composed of Angelica gigas (Angelicae Gigantis Radix), Cnidium officinale (Cnidii Rhizoma), Paeonia lactiflora (Paeonia Radix) and Rehmannia glutinosa (Rehmanniae Radix Preparata). Paeoniflorin, one of active components in Samul-tang has anti-platelet, anti-inflammation, anti-cancer and neuroprotective properties. However, there is no information about the effects of gender and food intake on the pharmacokinetics of paeoniflorin till now. AIM OF THE STUDY: This study was conducted to investigate whether food and gender could influence pharmacokinetic profiles of paeoniflorin after oral administration of Samul-tang. MATERIALS AND METHODS: Male and female rats were administered with a single oral dose of Samul-tang equivalent to 80 mg/kg of paeoniflorin. Plasma concentrations of paeoniflorin were measured by high-performance liquid chromatography. The statistical differences of each group were evaluated using the analysis of variance (ANOVA) or Student t-test. RESULTS: The pharmacokinetic parameters of paeoniflorin were not significant different by gender difference. However, the maximum plasma concentration (C(max), 0.47±0.29 µg/mL versus 1.10±0.35 µg/mL), area under the concentration-time curve (AUC(0→∞), 1.41±0.89 h · µg/mL versus 3.12±1.61 h · µg/mL) and relative bioavailability (F(rel)=2.21) of fed rats were significantly increased in comparison with those of fasted rats (P<0.05). CONCLUSION: Taken together, food intake can affect both the rate and extent of absorption of paeoniflorin when Samul-tang was administered orally. Furthermore, this study demonstrates a readily preparative HPLC method in the research of traditional herbal medicine.

Pharmacokinetic comparisons of albiflorin and paeoniflorin after oral administration of Shaoyao-Gancao-Tang and single herb Paeony decoction to rats.

Shaoyao-Gancao-Tang (SGT) is a traditional Chinese prescription containing Radix Paeoniae alba and Radix Glycyrrhizae and is commonly used to relieve pains. Albiflorin and paeoniflorin are the main effective compounds of Radix Paeoniae alba, and the pharmacokinetic differences of the two compounds in rats after oral administration of SGT and single herb Paeony decoction were studied. At different time points (5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 360, and 540 min) after administration, plasma concentrations of albiflorin and paeoniflorin were determined using a simple and reliable UPLC method, and main pharmacokinetic parameters were evaluated. It was found that there were significant differences (p < 0.05 or p < 0.01) between the two groups. The results indicated that some components in the other ingredient herb of SGT (Radix Glycyrrhizae) had a pharmacokinetic interaction with albiflorin and paeoniflorin and hence reduced their systematic exposure level.

Comparative pharmacokinetic study of paeoniflorin and albiflorin after oral administration of Radix Paeoniae Rubra in normal rats and the acute cholestasis hepatitis rats.

A comparative study was designed and conducted to compare the pharmacokinetic difference of paeoniflorin and albiflorin after oral administration of Radix Paeoniae Rubra to normal rats and the acute cholestasis hepatitis rats induced by alpha-naphthylisothiocyanate (ANIT). UPLC-ESI-MS/MS method was employed to determine the level of paeoniflorin and albiflorin in rat plasma using geniposide as the internal standard (IS). Unpaired Student's t-test was used for the statistical comparison. The investigation showed that there were significant differences between the normal rats and the acute cholestasis hepatitis rat groups in calculated parameters, such as AUC(0-t), AUC(0-∞), T(max) and CLz/F. The results indicated that acute liver injury in rats could alter the pharmacokinetics of drug. Since patients are the final users of the drug, it is essential to investigate the pharmacokinetics of the drug in disease status. Therefore, we used normal rats and the acute cholestasis hepatitis rats to study pharmacokinetics of Radix Paeoniae Rubra with the purpose of examining the influence of disease on the metabolic course.