Wenzhe Huang

Study on the anti-gout activity of chlorogenic acid: improvement on hyperuricemia and gouty inflammation.

Gout is a metabolic disorder associated with hyperuricemia resulting in the deposition of monosodium urate (MSU) crystals in joints and tissues. Lowering serum uric acid (Sur) levels and anti-inflammation are highly essential in treating gout. Chlorogenic acid (CA), as one of the most abundant polyphenols in the Chinese medicines, has been rarely reported to have an anti-gout effect. The model of potassium oxonate (PO)-induced hyperuricemia in mice and MSU crystal-induced inflammation in rats has been established in this study. The potential beneficial effects and mechanisms of CA on hyperuricemia and gouty arthritis were elucidated. The results demonstrated that CA significantly decreased the Sur level by inhibiting the xanthine oxidase (XOD) activity but not increasing the urinary uric acid (Uur) level. In addition, CA also exhibited the effect of suppressing paw swelling. Further investigation indicated that CA improved the symptoms of inflammation induced by MSU crystals by inhibiting the production of proinflammatory cytokines including interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). The present study suggests that CA may have a considerable potential for development as an anti-gouty arthritis agent for clinical application.

Identification of the major metabolites of tectorigenin in rat bile by liquid chromatography combined with time‐of‐flight and ion trap tandem mass spectrometry

A novel methodology for the identification of tetorigenin and its metabolites in rat bile has been created using liquid chromatography (LC) combined with time-of-flight (TOF) and ion trap multiple mass spectrometry (IT-MSn). As a means to discriminate amongst unknown organic compounds in complex biological matrices, the proposed methodology relies upon the combination of LC/TOF-MS to provide accurate mass measurements in generating a molecular formula while benefiting from the complementary structural information provided by the LC/IT-MSn. In this study, the combined approach has been applied to the metabolic fingerprinting chromatograms of rat bile samples before and after tectorigenin administration. All possible metabolites are investigated based on accurate mass data and isotope function using LC/TOF-MS and structural confirmation using LC/IT-MSn. Seven phase II metabolities of tectorigenin in rat bile have been successfully elucidated using this novel LC approach and are being reported for the first time.

Anti-hyperuricemic and nephroprotective effects of rhein in hyperuricemic mice.

Hyperuricemia has been considered to be a key risk factor for kidney disease. The formation of uric acid crystals in the kidney further stimulates an intensive inflammatory response. Rhein possesses various pharmacological activities, including anti-inflammatory, antioxidative, antitumor, purgative effects, and so on. To our knowledge, no previous work has been reported about the therapeutic effect of rhein on urate nephropathy. In this study, a model of hyperuricemia and nephropathy induced by adenine and ethambutol in mice was established. Meanwhile, the potential beneficial effects and mechanisms of rhein on hyperuricemia and nephropathy were also investigated. The results demonstrated that rhein significantly decreased the serum uric acid level by inhibiting the xanthine oxidase activity and increasing the excretion of urinary uric acid. In addition, rhein also markedly improved kidney damage related to hyperuricemia. Further investigation indicated that rhein improved the symptoms of nephropathy through decreasing the production of proinflammatory cytokines, including interleukin 1β, prostaglandin E2, and tumor necrosis factor-α and inhibiting the expression of transforming growth factor-β1. The present study suggests that rhein may have a considerable potential for development as an anti-hyperuricemic and nephroprotective agent for clinical application.

Pharmacokinetics and tissue distribution of ginkgolide A, ginkgolide B, and ginkgolide K after intravenous infusion of ginkgo diterpene lactones in a rat model

Ginkgo diterpene lactones are compounds that are extracted from the Ginkgo biloba leaf and possess pharmacologic activities with neuroprotective effects. To address the poor bioavailability of ginkgo diterpene lactones, ginkgo diterpene lactone meglumine injection (GDLI) was formulated and is commercially available. In this study, a simple, sensitive and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for assessing the total amount and the amount of the prototype forms of ginkgolides A (GA), B (GB) and K (GK) in rat plasma and tissues. This method was used to calculate the concentrations of the hydrolysed carboxylic forms and assess the pharmacokinetics of the ginkgolides after intravenous (i.v.) GDLI administration in rats. Generally, all three ginkgolide forms showed dose-dependent plasma concentrations, and no obvious differences in pharmacokinetic parameters, i.e., area under the curve (AUC) of plasma concentration versus time and half-life, were observed after GDLI administration on 7 consecutive days. These ginkgolides primarily existed in the carboxylic form in the plasma, and the systemic concentrations of the carboxylic forms of GA and GB were 11- to 17- and 3- to 4-fold higher than those of their prototype forms, respectively. In contrast, dramatically increased levels of the GA and GB prototype lactones were detected in the liver and heart. GA, GB, and GK were extensively distributed in various organs/tissues; the highest levels were found in the kidneys, liver, and intestine, and the lowest levels were found in the brain. These data suggest that ginkgolides have difficulty crossing the blood-brain barrier and that their targets for protecting against cerebral ischaemia are located outside the central system.

Research on the change of chemical composition in productive process of Re Du Ning injection by HPLC/Q-TOF MS

A high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC/Q-TOF MS) was developed for the analysis of chemical composition change in the production process of Re Du Ning injection, a Chinese medicine preparation with a combination of Lonicera japonica Thunb., Gardenia jasminoides Ellis and Artemisia annua L. A total of 90 compounds from raw materials-intermediates-Re Du Ning injection were detected; among them, 55 compounds were identified or tentatively characterized, and the characteristic ions of different types of compounds were described. Based on these studies, the different types of compounds in the various process routes were analyzed. A total of 28 compounds, including seven iridoid glycosides and six monoterpenes from G. jasminoides Ellis, five iridoid glycosides, nine phenolic acids and one unknown compound from L. japonica Thunb., were transferred to Re Du Ning injection, and two unknown compounds were generated in the production process of Re Du Ning injection. The results indicated that the Chinese Medicine Pharmaceutical process control is very important. This method could provide some reference for other Chinese medicine preparations.

A new hetero dimeric terpenoid derivative, japonicaside C, from the flower buds of Lonicera japonica

Abstract A rare hetero dimeric terpenoid derivative, named japonicaside C, together with five known secoiridoid gloucosides were isolated from the flower buds of Lonicera japonica. The structures of these compounds were established on the basis of spectroscopic analyses. Japonicaside C is the first representative of a novel type of hetero dimeric terpenoid, biogenetically originated from a guaiane-type sesquiterpenoid and a secoiridoid glucoside. Anti-virus activity of the isolated compounds was evaluated in vitro.

Simultaneous determination of ginkgolides A, B and K in human plasma by UPLC-MS/MS and its application to the pharmacokinetic study of Ginkgo Diterpene Lactone Meglumine Injection in humans

We developed and validated a rapid, selective and sensitive ultra-performance liquid-chromatography mass-spectrometry (UPLC-MS/MS) method for quantifying ginkgolide A, ginkgolide B and ginkgolide K as hydrolyzed forms in Ginkgo Diterpene Lactone Meglumine Injection (manufactured by Jiangsu Kanion Pharmaceutical Co., Ltd., Lianyungang, Jiangsu, China) for pharmacokinetic studies. Three ginkgolide compounds and internal-standard (IS), bilobalide, were extracted from human plasma by liquid–liquid extraction using ethyl acetate after acidification, and were separated on an Ace C18-AR column (2.1 mm × 50 mm, 3 μm) using a mobile phase of water containing 20 mM ammonium formate (adjusting pH to 5.4 using formic acid) and acetonitrile by gradient elution. Quantification was performed using negative-ion electrospray-ionization (ESI), and the content of ginkgolides was determined using multiple reaction monitoring (MRM) modes. Pharmacokinetics was assessed after intravenous infusion administration of Ginkgo Diterpene Lactone Meglumine Injection (containing 25 mg ginkgolides) to 3 healthy male Chinese volunteers. Analysis of the standard curves by linear regression revealed a high linearity over a 100-fold dynamic range for the three ginkgolides (the lower limit of quantitation values were 0.189–0.200 ng mL−1). The relative standard deviations of intra- and inter-day measurements were less than 10.7%, and accuracies were between −4.6% and 12.3% in terms of relative error; the extraction recoveries from human plasma were 89.4–91.9%, 81.0–85.0% and 78.5–82.5% for ginkgolide A, ginkgolide B and ginkgolide K, respectively. In conclusion, UPLC-MS/MS is rapid and sensitive for simultaneous quantification of multiple ginkgolides from Ginkgo Diterpene Lactone Meglumine Injection in human plasma and is suitable for pharmacokinetic studies.

Pharmacokinetics of Ginkgolide B after Oral Administration of Three Different Ginkgolide B Formulations in Beagle Dogs

Ginkgolide B (GB), an important active constituent of Ginkgo biloba extract, has been used in clinical applications for the treatment of dementia, cerebral insufficiency or related cognitive decline. To investigate the main pharmacokinetic characteristics of three different GB formulations in beagle dogs, a simple, specific and sensitive LC-MS/MS method was established and validated. The separation of the analytes was achieved on an Agilent Eclipse Plus C18 column (1.8 μm, 2.1 × 50 mm) with a mobile phase consisting of water and acetonitrile. The flow rate was set at 0.4 mL/min. Quantitation was performed using multiple reaction monitoring (MRM) in negative ion mode, with the transitions at m/z (Q1/Q3) 423.1/367.1 for GB and m/z 269.3/170.0 for IS. The linear calibration curve of GB was obtained over the concentration range of 2–200 ng/mL. The intra- and inter-day precisions were <15% and the accuracies were within ±12.7%. The validated method was applied to compare the pharmacokinetic characteristics of GB in healthy beagle dogs after oral administration of three formulations (HME08, GB capsule prepared by hot-melt extrusion technology; LL06, GB pellet prepared by liquid layer technology; conventional GB tablet). The Cmax values of GB from different formulations in beagle dog plasma were 309.2, 192.4 and 66.6 µg/L, and the AUC values were 606.7, 419.1 and 236.2 µg/L·h, respectively. The data suggested that the exposure level of GB from HME08 and LL06 in beagle dog plasma was greatly improved compared with conventional tablets. This study should be helpful for the design and development of oral GB preparations.

Comparative pharmacokinetic profiles of tectorigenin in rat plasma by UPLC-MS/MS after oral administration of Iris tectorum Maxim extract and pure tectoridin.

Iris tectorum Maxim, a well-known herb medicine, is commonly used for treatment of inflammation, cough, and pharyngitis for a long time in China. Tectoridin, main active ingredient of Iris tectorum Maxim, is often used for its quality control. This study was aimed to analyze the pharmacokinetic profile of tectorigenin (the metabolite of tectoridin) after oral administration of I. tectorum Maxim extract, and to compare the pharmacokinetic characterization of tectorigenin after oral administration of I. tectorum Maxim extract (ITME) and pure tectoridin (PT) in rats. In addition, a simple, reliable and sensitive UPLC-MS/MS method was developed for determination of tectorigenin in rat plasma, using kaempferol as internal standard. The processed samples were separated on a Poroshell 120 SB-C₁₈ column and detected by positive electrospray ionization in multiple reaction monitoring (MRM) mode. The method validation results indicated that the established method was simple, specific and reliable. The pharmacokinetic results showed that the plasma concentration of tectorigenin in ITME group was much higher than that of the PT group (p<0.01). Moreover, compared to PT group, t₁/₂ value and AUC(0-∞) value were also notably increased in ITME group (p<0.01). In conclusion, potential interaction exists between those chemical components in ITME, and the co-existing components in ITME could notably promote the absorption of tectoridin in rats, however, the exact compound(s) which enhance the absorption of tectoridin should be investigated in future study.

Qualitative and quantitative evaluation of ginkgo terpene lactone raw material by HPLC/Q-TOF MS combined with HPLC-DAD-ELSD

Ginkgo terpene lactone raw material (GTL) is extracted and purified from the dry leaves of Ginkgo biloba L., and it is the raw material in ginkgo diterpene lactone meglumine injections for treating patients suffering from mild to moderate cerebral infarction (manufactured by Jiangsu Kanion Pharmaceutical Co., Ltd., Lianyungang, Jiangsu, China). In the present study, an efficient strategy was developed for the characterization and identification of chemical components in GTL using high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (HPLC/Q-TOF MS/MS) combined with online valve switching. The structures of compounds were elucidated based on the accurate mass measurements, the fragmentation patterns of standards and the fragment ion at m/z 57.0700 of the tert-butyl group. As a result, 12 ginkgo terpene lactones were screened and identified from GTL, including ginkgolide A, B, C, J, M, K, L, Q, and P as well as bilobalide, one isomer of ginkgolide C and one isomer of ginkgolide A. Furthermore, four main ginkgolides (ginkgolide A, B, C and K) were simultaneously determined using a high performance liquid chromatograph coupled with a diode-array detector and an evaporative light scattering detector method (HPLC-DAD-ELSD) for the first time. The quantitative analytical method was fully validated with respect to linearity (r2 > 0.998), sensitivity, precision, accuracy (the recovery was between 99.7% and 100.4%), and robustness. Ten batches of samples were detected by HPLC-DAD-ELSD, indicating that the proposed approach was applicable for the evaluation of GTL quality.