The therapeutic effect of Xuanbai Chengqi Decoction on chronic obstructive pulmonary disease with excessive heat in the lung and fu-organs based on gut and lung microbiota as well as metabolic profiles.

As a prescription for treating lung inflammation and intestinal diseases, Xuanbai Chengqi Decoction (XBCQD) in clinical practice can effectively treat COPD with excessive heat in the lung and fu-organs, which is characterized by phlegm-heat accumulation in the lung and constipation. This study aims to find the potential biomarkers of COPD with excessive heat in the lung and fu-organs from two aspects of lung and intestine based on metabolomics and microbiota analysis, and to evaluate the efficacy of XBCQD as well as to explore the mechanism of drug function according the regulating effect of drugs on these markers. The HPLC-Q-TOF-MS/MS, 16SrDNA technology and multiple statistical methods were used to trace the process of disease and curative effect with XBCQD. Results showed that the onset and development of disease was associated with the imbalance of 41 differential metabolites in plasma, bronchoalveolar lavage fluid and feces and 82 bacteria at the levels of phylum, class, order, family and genus from lung and intestine, including Escherichia-Shigella. However, after treatment with XBCQD, 30 differential metabolites mainly involving in the metabolism of linoleic acid, taurine and hypotaurine metabolism, arachidonic acid metabolism, biosynthesis of primary bile acids, tryptophan metabolism, arginine and proline metabolism and 65 pulmonary and intestinal bacteria at all levels were reversed in the drug group. In addition, the results of the correlation analysis showed that specific microbiota from lung and intestine and reversed differential metabolites had a significant correlation, and they could affect each other in the course of disease occurrence and treatment. This study preliminarily confirmed that XBCQD can be used to treat COPD with excessive heat in the lung and fu-organs through lung-intestine simultaneous treatment. It also provided new strategies for the treatment of lung diseases or intestinal diseases, and new research ideas for the evaluation of drug efficacy.

Leonurus japonicus Houtt. (Motherwort): Systematic research through chemical profiling, stability under controlled conditions and pharmacokinetic analysis on screening Q-markers for quality control.

Leonurus japonicus Houtt. (Motherwort) is the fresh or dried aerial part of Leonurus japonicus Houtt. (Labiaceae), which is widely used in clinical practice and daily life, used to treat gynecological diseases. However, the differences between different parts, single index component in Pharmacopoeias and the less stability of active ingredients affect its clinical efficacy. This study aimed to find the multi-active compounds between different parts of Motherwort to ensure its clinical efficacy, which related to stability and had pharmacokinetic behavior. Firstly, HPLC-Q-TOF-MS/MS was used to analyze the components in vitro and in vivo, as well as multivariate statistical analysis and network pharmacology analysis was conducted to find the significant different components related to activity. Secondly, the content determination methods were established to study the stability of effective components during storage in order to establish the content limit for quality control of Motherwort. Thirdly, UFLC-MS/MS was used to analyze the pharmacokinetic behavior of active components in Motherwort. The results showed that a total of 131 chemical constituents were identified in vitro and 21 prototype absorption compounds and 72 metabolites were found in vivo. Meantime, multivariate statistical analysis and network pharmacology analysis was combined to find that leonurine, stachydrine and trigonelline were activity-related substance, which could be used as active components related to pharmacodynamics in different parts. Then the stability variation trend and content limit of three alkaloids were found, which could be used for the quality control of Motherwort. Furthermore, the results showed that three alkaloids had pharmacokinetic behavior in vivo. 3 alkaloids were screened, which could be used as active components most closely related to pharmacodynamics among different parts. The stable stage, assay tolerance and pharmacokinetic characteristics were studied by the active substances, which could provide a basis for quality control and clinical medication of Motherwort.

Determination and Comparison of Short-Chain Fatty Acids in Serum and Colon Content Samples: Alzheimer's Disease Rat as a Case Study.

Short-chain fatty acids (SCFAs) are the main microbial fermentation products from dietary fibers in the colon, and it has been speculated that they play a key role in keeping healthy in the whole-body. However, differences in SCFAs concentration in the serum and colon samples had attracted little attention. In this study, we have optimized the extract and analysis methods for the determination of ten SCFAs in both serum and colon content samples. Methanol and acetonitrile were chosen for extraction of SCFAs from serum and colon content samples, respectively. Biological samples were collected from Alzheimer's disease rats treated by extract of Schisandra chinensis (Turcz.) Baill (SC-extract) were taken as research objects. The results showed that, the relative peak intensities of SCFAs in the colon content from all groups were quite similar, and the trend was identical in the serum samples. Compared with the values in humans, the ratio of ten SCFAs in rat's colon was similar, while the percent of acetate in rat's serum was significantly higher. For therapy of Alzheimer's disease (AD), SC-extract decreased the concentration of butyrate, 3-Methyvalerate, and caproate in the serum samples towards the trend of normal rats. This study may help our understanding of how SCFAs are transported across colonic epithelium in healthy and diseased organisms.

Bioactive flavonoids in medicinal plants: Structure, activity and biological fate.

Flavonoids, a class of polyphenol secondary metabolites, are presented broadly in plants and diets. They are believed to have various bioactive effects including anti-viral, anti-inflammatory, cardioprotective, anti-diabetic, anti-cancer, anti-aging, etc. Their basic structures consist of C6-C3-C6 rings with different substitution patterns to produce a series of subclass compounds, and correlations between chemical structures and bioactivities have been studied before. Given their poor bioavailability, however, information about associations between structure and biological fate is limited and urgently needed. This review therefore attempts to bring some order into relationships between structure, activity as well as pharmacokinetics of bioactive flavonoids.

Simultaneous determination of hydrophilic and lipophilic constituents in herbal medicines using directly-coupled reversed-phase and hydrophilic interaction liquid chromatography-tandem mass spectrometry.

Limitations in the separation ability of conventional liquid chromatography system remains a challenge in developing a versatile method for simultaneously determining both hydrophilic and lipophilic constituents in herbal medicines (HMs). To measure compounds covering a broad polarity span in HMs, we developed a directly-coupled reversed-phase and hydrophilic interaction liquid chromatography-tandem mass spectrometry system. Samples were firstly separated according to lipophilicity by using a C18 column. Utilizing a T-piece as connector, the eluent was then pumped into an amide column to get further separation that mainly based on the hydrogen bonding effects. Dan-Qi pair, an extensively used herb-combined prescription in China, was selected to test the practicability and performance of the established system. A total of 27 components, containing 9 hydrophilic and 18 lipophilic constituents, were simultaneously determined using a schedule multiple reaction monitoring method in 15 min. Up to 69.9% content could be monitored in one injection in Dan-Qi pair extract, showing a significant advantage over previous methods. The proposed method was expected to benefit the controllability of herbal medicines.

Brain-derived Neurotrophic Factor Signaling Mediates the Antidepressant-like Effect of the Total Flavonoids of Alpiniae Oxyphyllae Fructus in Chronic Unpredictable Mild Stress Mice.

The present study verified the antidepressant-like effects of the total flavonoids of Alpinia oxyphylla Miq. (AOF) using the chronic unpredictable mild stresses paradigm and explored the mechanism that underlies antidepressant-like effects of AOF in mice. Previous research has shown that tropomyosin-related kinase B (TrkB) receptor-mediated extracellular regulated protein kinases (ERK) signaling pathways participate in depression pathophysiology. Therefore, we aimed to explore whether AOF improved depression-like behaviors by increasing activity of ERK pathways mediated by TrkB. Results showed that AOF significantly reduced the immobility time in the forced swimming test and increased the sucrose preference in sucrose preference test. In addition, decreased phosphorylated cyclic adenosine monophosphate response element-binding protein (pCREB)/CREB, pERK/ERK, and pTrkB/TrkB levels in the hippocampus induced by chronic unpredictable mild stresses were reversed by intragastric administration of AOF. Results suggested that AOF increased pCREB/CREB, pERK/ERK, and pTrkB/TrkB levels by acting on the TrkB receptor. To verify this hypothesis, mice were pretreated with the TrkB inhibitor K252a (or 0.1% dimethyl sulfoxide, intraperitoneally, 2 weeks), before the intragastric administration of AOF. This resulted in an absence of antidepressant-like effects, as well as no activation of pERK/pCREB/BDNF signaling pathways. Results demonstrated that AOF might exert antidepressant-like effects by targeting TrkB receptor-mediated pERK/pCREB/BDNF signal systems, which could help to identify the AOF receptor. Copyright © 2016 John Wiley & Sons, Ltd.

The comparative pharmacokinetics of four bioactive ingredients after administration of Ramulus Cinnamomi-Radix Glycyrrhizae herb pair extract, Ramulus Cinnamomi extract and Radix Glycyrrhizae extract.

Ramulus Cinnamomi (RC)-Radix Glycyrrhizae (RG) is a classic herb pair, which is commonly used as a fixed form to treat cardiovascular disease in the clinic. Our work aimed to compare the pharmacokinetic difference of cinnamic acid, liquiritin, isoliquiritigenin and glycyrrhetinic acid in rats after oral administration of the RC-RG herb pair extracts [Guizhigancao Decoction (GGD) and Lingguizhugan Decoction (LGZGD)] and the single RC or RG extract. A HPLC-MS method was developed and validated to study comparative pharmacokinetics. The pharmacokinetic parameters (Cmax , AUC, MRT) of four compounds between the RC-RG herb pair group and the single herb (RC or RG) group showed significant differences (p < 0.05). Compared with the single herb (RC or RG) group, higher peak concentration, slower elimination and larger exposure could be observed after giving the RC-RG herb-pair extracts. The pharmacokinetic differences might indicate the relativity of remedy in the RC-RG herb pair and provide scientific information for rational administration of the drug in the clinic. Copyright © 2016 John Wiley & Sons, Ltd.

[Bioactive consistency evaluation of cardiotonic pill using marker genes].

The study is aimed to develop a method in evaluation of the bioactive consistency of cardiotonic pill (CP). HepG2 cell line was employed as a biological detector. After treated with CP for 24 h, gene chip and qRT-PCR were used to select m RNAs that can represent the bioactivity of CP. Then similarity between different batches of CP were calculated based on expression levels of marker genes to evaluate the bioactive consistency of CP. Marker genes were selected according to the criteria as follows: 1 fold change < 0.67 or > 1.5; 2 potential relevance to curative effects; 3 extensive involvement in the cellular functions and clustering analysis categories; 4 dose-dependent effect. A total of 10 genes were selected as bioactive markers of CP. Angular cosine was calculated to evaluate the similarity between two samples. The method was validated using intra-day precision and inter-day precision. Using angular cosine similarity, the intra-day and inter-day precision were 0.4% and 0.6%, respectively. The similarities of 6 batches of CDPs ranged from 0.992 to 0.999, and 1 batch of Compound Danshen Tablet was 0.534. The established method is specific and accurate, and provides comprehensive and objective evaluation of bioactive quality of CDPs. It can also benefit the bioactive consistency evaluation of other compounds in traditional Chinese medicines.

Evaluation of the protective effect of Zhi-Zi-da-Huang decoction on acute liver injury with cholestasis induced by α-naphthylisothiocyanate in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Zhi-Zi-Da-Huang decoction (ZZDHD), a classic traditional Chinese medicine (TCM) formula composed of four herbal medicines, has been widely used to treat various hepatobiliary disorders for a long time in China. However, the pharmacological effect of ZZDHD on liver injury with cholestasis is unrevealed. AIM OF THE STUDY: To investigate the hepatoprotective effect of ZZDHD against α-naphthylisothiocyanate (ANIT)-induced liver injury with cholestasis in rats. MATERIALS AND METHODS: The rats were intragastrically (i.g.) given ZZDHD at doses of 1, 2 and 4 g/kg (crude drug/body weight) once a day for seven days and treated with ANIT (75 mg/kg via i.g.) to cause liver injury at 12h after the fifth administration. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltranspeptidase (γ-GTP), total bilirubin (TBIL), direct bilirubin (DBIL) and total bile acid (TBA), as well as bile flow were measured at 48 h after ANIT treatment to evaluate the protective effect of ZZDHD. Moreover, the possible protective mechanisms were elucidated by assays of liver enzyme activities and component contents including malondialdehyde (MDA), myeloperoxidase (MPO), lipid peroxide (LPO), superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). The biochemical observations were supplemented by histopathological examination. Ultra fast liquid chromatography-mass spectrometry (UFLC-MS) was used for the phytochemical analysis of ZZDHD. RESULTS: The high dose (4 g/kg) and middle dose (2g/kg) of ZZDHD exhibited significant and dose-dependent protective effect on ANIT-induced liver injury with cholestasis by reversing the changes in bile flow, the serum and hepatic enzymes, and histopathology of the liver tissue. Meanwhile, it was found that the low dose (1g/kg) of ZZDHD did not improve the biochemical indexes except serum TBIL, DBIL and TBA, which showed little protective effect. Phytochemical analysis revealed the presence of sixteen compounds in ZZDHD. CONCLUSIONS: This study indicates that ZZDHD exerted a hepatoprotective effect on ANIT-induced liver injury with cholestasis in rats, and the mechanism of this activity is possibly related to its antioxidant properties.

Protective effect of n-butanol extract from Alpinia oxyphylla on learning and memory impairments.

Alzheimer's disease (AD) is one of the major neurological diseases of the elderly. How to safely and effectively remove the toxic Aß42 peptide through blood-brain barrier (BBB) is considered to be an effective method for the prevention and treatment of AD. The compounds whose molecule weight is less than 400 Da and the number of hydrogen bonding is less than 10 are more likely to permeate BBB. In our previous study, we have several small molecule compounds which are isolated from n-butanol (NB) extract of Alpinia oxyphylla that are similar with this kind of compounds This study explored the neuroprotective effects of the NB significantly protected against learning and memory impairments induced by Aß(1-42) in Y-maze test, active avoidance test and Morris water maze test. Besides, NB (180 mg/kg, 360 mg/kg) was able to attenuate the neuronal damage and apoptosis in the frontal cortex and hippocampus in mice. In addition, the inhibition of ß-secretase and the level of Aß(1-42) are also involved in the action mechanisms of NB in this experimental model. This study provided an experimental basis for clinical application of A. oxyphylla Miq. in AD therapy.

The effects of sesquiterpenes-rich extract of Alpinia oxyphylla Miq. on amyloid-ß-induced cognitive impairment and neuronal abnormalities in the cortex and hippocampus of mice.

As a kind of medicine which can also be used as food, Alpinia oxyphylla Miq. has a long clinical history in China. A variety of studies demonstrated the significant neuroprotective activity effects of chloroform (CF) extract from the fruits of Alpinia oxyphylla. In order to further elucidate the possible mechanisms of CF extract which mainly contains sesquiterpenes with neuroprotection on the cognitive ability, mice were injected with Aß(1-42) and later with CF in this study. The results showed that the long-term treatment of CF enhanced the cognitive performances in behavior tests, increased activities of glutathione peroxidase (GSH-px) and decreased the level of malondialdehyde (MDA), acetylcholinesterase (AChE), and amyloid-ß (Aß), and reversed the activation of microglia, degeneration of neuronal acidophilia, and nuclear condensation in the cortex and hippocampus. These results demonstrate that CF ameliorates learning and memory deficits by attenuating oxidative stress and regulating the activation of microglia and degeneration of neuronal acidophilia to reinforce cholinergic functions.

[Analysis on influential factors in China's exports of primary and semi-finished products of traditional Chinese medicine to ASEAN].

Two regression models, based on panel data over the period of 2000-2011, are built and used to analyze what factors determine China's exports of primary and semi-finished products of traditional Chinese medicine to ASEAN. The results indicate that, China GDP, the ratio of ASEAN to China GDP per capita, average export price, the ratio of state-owned assets to total assets, have a significant positive influence on the export volumes of primary products of Chinese medicine. At the same time, RMB appreciation, the ratio of three kinds of foreign-invested assets to total assets, China-ASEAN Early Harvest Program, ASEAN-China Free Trade Area have a significant negative influence. In respect of the export volumes of semi-finished products of Chinese medicine, the significant influential factors are ASEAN GDP and the ratio of ASEAN to China GDP per capita. The former is positive and the latter is negative. In order to optimize the commodity composition of experts, it is needed to increase export volumes of both primary and semi-finished products of Chinese medicine. According to the analysis above, some proposals are put forward, such as, improving the performance of foreign capital, playing an exemplary and leading role in technological innovation by state-owned enterprises, taking advantage of bargaining power of suppliers, increasing outward foreign direct investment.

Ligustrazine attenuates elevated levels of indoxyl sulfate, kidney injury molecule-1 and clusterin in rats exposed to cadmium.

In this study, we aimed at evaluating the effect of ligustrazine, a major constituent of Ligusticum wallichii from traditional Chinese medicine, on Cd-induced changes in nephrotoxicity indices. Rats were divided into four experimental groups: control; ligustrazine; Cd and ligustrazine+Cd. Cd treated alone group showed significant decreases (P<0.05) in body weight, renal levels of superoxide dismutase (SOD) and glutathione reductase (GR); and significant increases (P<0.05) in urine volume (24h), pH values, serum blood urea nitrogen (BUN), serum uric acid, kidney malondialdehyde (MDA), urinary total protein, urinary glucose, urinary lactate dehydrogenase (LDH) and urinary alkaline phosphatase (ALP). Apart from indoxyl sulfate (a uremic toxin), two newly accepted nephrotoxicity biomarkers including kidney injury molecule-1 (kim-1) and clusterin were also found to be increased. Nonetheless, all these effects induced by Cd were reversed upon treatment by ligustrazine although it failed in decreasing the concentrations of Cd in kidney and urine. Histopathological studies in Cd-treated rats exhibited renal tubule damage, which was also ameliorated by ligustrazine pretreatment. These results suggest that ligustrazine exhibits protective effects on Cd-induced nephrotoxicity. Additionally, this study also demonstrates Cd exposure induces elevated levels of indoxyl sulfate in serum and kidney, and clusterin in urine.

Validation of HPLC method for the determination of polydatin in giant knotweed rhizome.

An HPLC method has been developed to determine polydatin in giant knotweed rhizome. In order to systematically validate the method, specificity, precision, linearity of reference solution and test solution, repeatability, reproducibility, accuracy, stability and robustness were measured. In the robustness test, a one-variable-at-a-time procedure was applied to evaluate the influence of slight variations in method factors, including the flow rate, the column temperature, the extraction time, and etc., on the assay result of polydatin. No significant differences were found when the process parameters changed during the experimental domain. And system suitability test limits were defined based on the robustness test. Results showed that the developed method was accurate, reproducible and robust.

Elution-extrusion counter-current chromatography separation of two new benzyl ester glucosides and three other high-polarity compounds from the tubers of Pleione bulbocodioides.

INTRODUCTION: The tubers of Pleione bulbocodioides (Franch.) Rolfe, with gastrodin and benzyl ester glucosides as main components, have been used in traditional Chinese medicine for the treatment of various cancers and bacterial infections. Up to now, their official quality control method is still inadequate, and the difficulty of obtaining these high-polarity compounds is one of the major reasons. OBJECTIVE: To develop a rapid and efficient method for preparative separation of the high-polarity compounds gastrodin and benzyl ester glucosides. METHODS: An optimised solvent system composed of n-butanol:ethanol:water (20:1:20, v/v/v) was applied for the elution-extrusion counter-current chromatography (EECCC) separation. The upper phase was used as the stationary phase, and the lower phase was used as the mobile phase at a flow rate of 1.5 mL/min, a rotation speed of 850 rpm and a temperature of 35°C. RESULTS: Five high-polarity glucosides, including two new compounds, (E)-4-ß-D-glucopyranosyloxycinnamic acid 9-(4-ß-D-glucopyranosyloxybenzyl) ester (4 mg) and (Z)-2-(2-methylpropyl)butenedioic acid bis(4-ß-D-glucopyranosyloxybenzyl) ester (9 mg), and three main components, gastrodin (87 mg), dactylorhin A (60 mg) and militarine (15 mg), with HPLC purities of 95.4%, 96.4%, 91.1%, 97.2% and 95.5% respectively, were yielded from 400 mg of the prepared sample. CONCLUSION: Elution-extrusion counter-current chromatography could be used as a useful tool for the separation of high-polarity compounds such as gastrodin and benzyl ester glucosides and the enrichment of the minor ones.

[Comparative study on pharmacokinetics of senkyunolide I after administration of simple recipe and compound recipe in rats].

OBJECTIVE: To develop a LC-MS method for the determination of senkyunolide I (SI) in rat plasma, in order to observe whether there is significant change in the pharmacokinetics parameters of complex prescriptions of Huoluoxiaolingdan (HLXL) and single herbal extracts from Ligusticum chuanxiong Hort. in rats, and assess the effect of other components in HLXL on the pharmacokinetics of SI. METHOD: Twelve male Sprague-Dawley (SD) rats were randomly divided into two groups, and orally administered with extract from HLXL and L. chuanxiong (both equal to SI 4.53 mg x kg(-1)). Their blood was collected at different time points for LC-MS, in order to detect the plasma concentration of SI. The pharmacokinetic parameters of SI were calculated by DAS 2.0 software. SPSS 16.0 software was used for independent-sample T-test and Nonparametric T-test. RESULT: A linear relationship of SI ranged from 6.750 to 675.0 microg x L(-1), and with the lowest limit of detection being 6.750 microg L(-1). Both of the plasma concentration-time curves of SI were fitted with the two-compartment model for extract of HLXL and L. chuanxiong. The detected AUC and Cmax of SI showed significant difference, with no significant difference in other parameters. CONCLUSION: The LC-MS determination method established in this experiment was so exclusive, accurate and sensitive that it is suitable for pharmacokinetic studies on extracts of HLXL and SI from L. chuanxion. The experiment results show that other ingredients of HLXL have noticeable effect on the absorption of SI in rat plasma.

[Screening of hepatotoxicity fraction of Genkwa Flos and study on UPLC fingerprint of hepatotoxicity fraction].

OBJECTIVE: To look for the active fraction of ethanol extract of Genkwa Flos (EGF) induced hepatotoxicity and develop an UPLC fingerprint of the active fraction. METHOD: Target fraction of EGF induced hepatotoxicity was guided by the serum biochemical and histopathology methods. The UPLC method was applied to establish the chromatographic fingerprint. The separation was achieved on a BEH C18 column (2.1 mm x 50 mm, 1.7 microm) with a mobile phase consisting of acetonitrile and water containing 0.05% phosphate acid running gradient elution. The detection was carried out at 210 nm and the analysis was finished within 10 min. RESULT: The chloroform phase of EGF could be responsible for the hepatotoxicity of this herb. The common mode of the UPLC fingerprint was set up under the established condition. There were 17 common peaks in fourteen batches of herbs, eight of which were identified, and the similar degrees of the fourteen batches to the common mode were between 0.890-0.999. CONCLUSION: It is easy to locate the chloroform extraction of EGF with hepatotoxicity. And the UPLC fingerprint was developed for the above fraction, which could provide valuable references for safe and effective clinical use of EGF.

Neolignanamides, lignanamides, and other phenolic compounds from the root bark of Lycium chinense.

Seven new neolignanamides (1-7), including two pairs of cis- and trans-isomers, and a new lignanamide (8) were isolated from the EtOAc-soluble fraction of an EtOH extract of the root bark of Lycium chinense, together with 22 known phenolic compounds (9-30), four of which were obtained from the genus Lycium for the first time. Compounds 5, 6, and 7 are unusual dimers having a rare connection mode between the two cinnamic acid amide units, while compounds 6, 7, and 8 are the first naturally occurring dimers derived from two dissimilar cinnamic acid amides. The cinnamic acid amides, neolignanamides, and lignanamides possess moderate radical-scavenging activity against the DPPH (2,2-diphenyl-1-picrylhydrazyl) and superoxide radicals.

[Analysis on influential factors of Chinese medicinal herb growers' willingness to use green pesticides: evidence on Panax notoginseng production areas in Wenshan, Yunnan province].

The purpose of the article is to apply a binary logistic model to analyze the major factors, which influence Chinese medicinal herb growers' willingness to use green pesticides by using survey data collected in Wenshan, Yunnan Province. The results indicate that, output per capita, average pesticide cost per mu, cognition of pesticide residues, expectations on Panax notoginseng prices, cognition of pesticides' effect of pests control, cognition of P. notoginseng prices of low pesticide residues have a significant influence on growers' willingness to use green pesticides. According to the analysis above, some proposals for enhancing Chinese medicinal herb growers' willingness to use green pesticides are put forward, such as, moving toward the intensive planting systems, fetching down the pieces of green pesticides, emphasizing and propagating the advantages of green pesticides, keeping the prices of Chinese medicinal herb running at steady rates.

Simultaneous quantification of three iridoids in rat plasma after oral administration of Zhi-zi-chi decoction using LC-MS.

A sensitive and efficient liquid chromatography-mass spectrometry (LC-MS) method was developed and validated for the simultaneous determination of geniposide, 6α-hydroxygeniposide, and genipin gentiobioside in rat plasma. After the addition of internal standard (I.S.) salidroside and acidification (formic acid, 0.1%), plasma samples were carried out by protein precipitation with acetonitrile and separated on a Kromasil C(18) column (200 mm × 4.6 mm, 5 µm) within a runtime of 15.0 min. The linear ranges were 2-250 ng/mL for both 6α-hydroxygeniposide and genipin gentiobioside and 2-2000 ng/mL for geniposide, respectively. The lower limit of quantification (LLOQ) was 2 ng/mL for all the analytes. The validated method was successfully applied to the pharmacokinetics study of geniposide, 6α-hydroxygeniposide, and genipin gentiobioside in rats after oral administration of Zhi-zi-chi decoction.