Jie Zhong

Increased Systemic Exposure to Rhizoma Coptidis Alkaloids in Lipopolysaccharide-Pretreated Rats Attributable to Enhanced Intestinal Absorption

Rhizoma coptidis is a rhizome commonly used in traditional Chinese medicine. After oral administration of rhizoma coptidis extract, the plasma concentrations of its effective alkaloid constituents are so low that their systemic therapeutic actions cannot be explained. This study aimed to investigate the influence of lipopolysaccharide (LPS) on the pharmacokinetics of the rhizoma coptidis alkaloids. Pharmacokinetic experiments were performed with rats; both in vitro absorption and efflux experiments were carried out with everted rat gut sacs, whereas in vitro metabolism experiments were conducted with rat liver microsomes and intestinal S9 fractions. Mucosal changes were evaluated with light microscopy and transmission electron microscopy. The results showed that, in rat plasma, LPS pretreatment increased systemic alkaloid exposure. LPS pretreatment increased the in vitro absorption of the alkaloids and decreased their efflux. The efflux of vinblastine and rhodamine 123, P-glycoprotein substrates, also was decreased. The absorption of fluorescein isothiocyanate-labeled dextran (average molecular mass, 4 kDa), a gut paracellular permeability probe, was not influenced. Obvious damage was observed in the mucosa, but the tight junctions between epithelial cells remained intact. Intestinal, rather than hepatic, alkaloid metabolism was decreased. These findings indicated that LPS pretreatment increased systemic exposure to the alkaloids through enhancement of their absorption, which was related to decreased intestinal efflux and metabolism. The results add to the understanding of why rhizoma coptidis is active despite the low plasma concentrations of the rhizoma coptidis alkaloids measured in normal subjects and experimental animals.

Relationships between pharmacokinetics and efficacy of Xie-xin decoction in rats with experimental ulcerative colitis

ETHNOPHARMACOLOGICAL RELEVANCE Xie-xin decoction (XXD) has been used as a classic formula in China for the treatment of gastrointestinal dysfunction such as ulcerative colitis (UC). However, no potential action mechanisms and active compounds had been systematically investigated. AIM OF THE STUDY To explore the effectiveness and the material basis of XXD in trinitrobenzene sulfonic acid (TNBS)-induced UC rats. MATERIALS AND METHODS XXD was administered orally for 8 days at a dosage of 2 or 4g/kg/day. Plasma pharmacokinetic properties and colon tissue concentrations of multiple compounds from XXD were detected. Tissue damage scores, production of interleukin (IL)-10 and myeloperoxidase (MPO), expression of tumor necrosis factor-alpha (TNF-α) and nuclear factor-kappa Bp65 (NF-κBp65) in colon tissues were examined. Canonical correlation analysis was performed to evaluate the relationships between pharmacokinetics and efficacy to elucidate significantly active compounds of XXD. RESULTS XXD promoted the recovery of colitis and inhibited the colonic inflammation damage in UC rats by reducing the level of MPO and the expression of TNF-α and NF-κBp65, and increasing the production of IL-10 in colon tissues. Efficacy of XXD was positively related with AUC of five plasma compounds (baicalin, berberine, wogonoside, wogonin, and rhein) and concentrations of six colon tissue compounds (coptisine, jatrorrhizine, palmatine, berberine, baicalein and emodin), respectively. CONCLUSIONS The multiple compounds in plasma and colon tissues from XXD might be the main material basis for therapeutic potentials in UC rats.

Identification and pharmacokinetics of multiple constituents in rat plasma after oral administration of Yinchenzhufu decoction.

ETHNOPHARMACOLOGICAL RELEVANCE Yinchenzhufu decoction (YCZFD) is a classical Chinese herbal formula and has been used to treat severe jaundice in chronic liver injuries since the Qing Dynasty (18th century CE). To identify the components absorbed into the blood in YCZFD and explore their pharmacokinetic profile for understanding the effective ingredients of YCZFD. MATERIALS AND METHODS After rats were given YCZFD by intragastric administration, the plasma was processed by precipitation of protein. The compounds in YCZFD extract and the plasma were identified by using high-resolution mass spectrometry with a database-directed strategy. The pharmacokinetics of multiple compounds from YCZFD in rat plasma was studied by using the established UPLC-MS/MS method. RESULTS Forty compounds in YCZFD extract and 21 prototype compounds with 11 metabolites in rat plasma were detected after oral administration. The pharmacokinetic parameters of glycyrrhizic acid, glycyrrhetic acid, cinnamic acid, ononin, atractylenolide III, and liquiritin from YCZFD were obtained in rats. CONCLUSIONS The identified constituents and the pharmacokinetic features of YCZFD are helpful for understanding the material bases of its therapeutic effects.

Content determination of the major constituents of Yinchenzhufu decoction via ultra high-performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry

In this study, we developed a method using ultra high-performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry for determining the contents of chlorogenic acid, atractylenolide I, atractylenolide III, benzoylaconine, benzoylmesaconine, benzoylhypaconine, glycyrrhizic acid, glycyrrhetic acid, liquiritigenin, and cinnamic acid in Yinchenzhufu decoction, a classic traditional Chinese medicine prescription. Separation was performed on a C18 column (4.6mm i.d.×250mm, 5μm) and achieved with good linearity (r(2)>0.9984) within 35min. Gradient elution was applied using a mobile phase of 0.05% acetic acid/acetonitrile. The analytes were quantified on an LCQ ion trap mass spectrometer in electrospray ionisation full-scan mode. Variations in the intra- and inter-day precision of all analytes were below 4.57%, and the accuracy was evaluated by a recovery test within the range of 97.88-102.25%. The method successfully quantified the 10 compounds in five sample batches of Yinchenzhufu decoction, and the results show that the method is accurate, sensitive, and reliable.

Renal Protective Role of Xiexin Decoction with Multiple Active Ingredients Involves Inhibition of Inflammation through Downregulation of the Nuclear Factor-κB Pathway in Diabetic Rats

In Chinese medicine, Xiexin decoction (XXD) has been used for the clinical treatment of diabetes for at least 1700 years. The present study was conducted to investigate the effective ingredients of XXD and their molecular mechanisms of antidiabetic nephropathy in rats. Rats with diabetes induced by high-fat diet and streptozotocin were treated with XXD extract for 12 weeks. XXD significantly improved the glucolipid metabolism disorder, attenuated albuminuria and renal pathological changes, reduced renal advanced glycation end-products, inhibited receptor for advanced glycation end-product and inflammation factors expression, suppressed renal nuclear factor-κB pathway activity, and downregulated renal transforming growth factor-β1. The concentrations of multiple components in plasma from XXD were determined by liquid chromatography and tandem mass spectrometry. Pharmacokinetic/pharmacodynamic analysis using partial least square regression revealed that 8 ingredients of XXD were responsible for renal protective effects via actions on multiple molecular targets. Our study suggests that the renal protective role of XXD with multiple effective ingredients involves inhibition of inflammation through downregulation of the nuclear factor-κB pathway, reducing renal advanced glycation end-products and receptor for advanced glycation end-product in diabetic rats.

Involvement of rat organic cation transporter 2 in the renal uptake of jatrorrhizine

Jatrorrhizine is a protoberberine alkaloid derived from Coptis chinensis concentrated extremely in rat kidney. In the present study, the involvement of rat organic cation transporter 2 (rOCT2) in the renal uptake of jatrorrhizine in rat was investigated through in vitro and in vivo experiments. Saturable and nonsaturable uptakes of jatrorrhizine were observed in rat kidney slices and rOCT2-Madin-Darby canine kidney (MDCK) cells. Michaelis-Menten constants of 677.8 and 21.0 µM, maximum uptake rate of 123 (pmol/min)/mg kidney and 13.7 (pmol/min)/mg protein, and nonsaturable uptake clearance of 0.054 (µL/min)/mg kidney and 0.032 (µL/min)/mg protein were observed in rat kidney slices and rOCT2-MDCK cells, respectively. As inhibitors of rOCT2, corticosterone, verapamil, and cimetidine can inhibit jatrorrhizine uptake in rat kidney slices and rOCT2-MDCK cells. Their median inhibitory concentration in rat kidney slices was 7, 78, and 538 µM, whereas that in rOCT2-MDCK cells was 1.07, 86.5, and 151.8 µM. Coadministration with 20 mg/kg corticosterone, a selective inhibitor of rOCT2, reduced the jatrorrhizine concentration in the cortex and medulla in the in vivo experiment. Thus, rOCT2 is mainly responsible for the renal uptake of jatrorrhizine in rat and in the regulation of jatrorrhizine concentration in the kidney.

Simultaneous quantification of multiple components in rat plasma by UPLC-MS/MS and pharmacokinetic study after oral administration of Huangqi decoction

A rapid, sensitive and accurate UPLC-MS/MS method was developed for the simultaneous quantification of components of Huangqi decoction (HQD), such as calycosin-7-O-β-d-glucoside, calycosin-glucuronide, liquiritin, formononetin-glucuronide, isoliquiritin, liquiritigenin, ononin, calycosin, isoliquiritigenin, formononetin, glycyrrhizic acid, astragaloside IV, cycloastragenol, and glycyrrhetinic acid, in rat plasma. After plasma samples were extracted by protein precipitation, chromatographic separation was performed with a C18 column, using a gradient of methanol and 0.05% acetic acid containing 4mm ammonium acetate as the mobile phase. Multiple reaction monitoring scanning was performed to quantify the analytes, and the electrospray ion source polarity was switched between positive and negative modes in a single run of 10 min. Method validation showed that specificity, linearity, accuracy, precision, extraction recovery, matrix effect and stability for 14 components met the requirements for their quantitation in biological samples. The established method was successfully applied to the pharmacokinetic study of multiple components in rats after intragastric administration of HQD. The results clarified the pharmacokinetic characteristics of multiple components found in HQD. This research provides useful information for understanding the relation between the chemical components of HQD and their therapeutic effects.

A systematic quality control method of Huangqi decoction: simultaneous determination of eleven flavonoids and seven triterpenoid saponins by UHPLC-MS

A novel method of ultra high-pressure liquid chromatography coupled with mass spectrometry (UHPLC-MS) was developed for the quantitative analysis of 18 major bioactive components from Huangqi decoction (HQD). HQD is a classic traditional Chinese medicine (TCM) commonly used to treat consumptive and chronic liver diseases. Chromatographic separation was performed on a reverse-phase C18 column for 30 min at a flow rate of 1 mL min−1. The optimum mobile phase for the gradient elution was 0.05% aqueous formic acid and acetonitrile. All of the analytes showed good linearity over the tested concentration ranges (r2 > 0.9972). The recoveries of the three concentration levels ranged from 91.14% to 106.21% with relative standard deviation (RSD) less than 4.69%. Intra- and inter-day precisions were less than 4.73% and 4.97%, respectively. Moreover, this method was successfully used to determine the content of HQD extracts in three different batches. Hence, this method could be used for the multi-component quality control of HQD.

Simultaneous determination of 14 major components in Longhu Rendan pills by ultra-high-performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry

A novel method based on ultra-high-performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry was developed for the simultaneous determination of the 14 major active constituents of Longhu Rendan pills. These 14 compounds were separated within 20 min in a C18 column (2.1 mm i.d. × 100 mm, 3 μm), and good linearity was achieved (r > 0.9980). Gradient elution was applied using a mobile phase of 0.01% formic acid containing 0.2 mM ammonium formate/acetonitrile. The analytes were quantified on an LCQ ion trap mass spectrometer in electrospray ionisation full-scan mode. Variations in the intra- and inter-day precisions of all analytes were below 4.60%, and the accuracy was evaluated by a recovery test within 94.41% to 103.39%. The method successfully quantified the 14 compounds in three sample batches of Longhu Rendan pills. Therefore, our method enables the highly accurate, sensitive and reliable determination of 14 major active constituents, which can aid the quality control investigation of Longhu Rendan pills.

Validated assay for the evaluation of multiple glucuronidation activities in human liver microsomes via liquid chromatography-tandem mass spectrometry

A sensitive and high-throughput liquid chromatography-tandem mass spectrometry system was developed and validated for the simultaneous determination of major human hepatic UDP-glucuronyltransferase forms in human liver microsomes. The analytes were detected using a triple-quadrupole mass spectrometer equipped with an electrospray ionization source in the negative ion and selected reaction monitoring modes. The method provided satisfactory linear concentration range, accuracy, precision, and stability. The developed method was successfully applied to the enzyme kinetic study of estradiol-3-O-glucuronidation, 4-methylumbelliferone-O-glucuronidation, propofol-O-glucuronidation, and 3-azido-3-deoxythymidine glucuronidation in human liver microsomes.