Changxiao Liu

Phytochemical and pharmacological studies on Radix Angelica sinensis

The roots of Angelica sinensis (RAS), are a Chinese herbal medicine traditionally used in prescriptions for replenishing blood, treating abnormal menstruation, and other womens diseases. It has also been widely marketed as health food for womens care in Asia, and as a dietary supplement in Europe and America. RAS is well-known for its hematopoietic, antioxidant, and immunoregulatory activities. RAS also possesses anti-cancer, memory, radioprotective, and neuroprotective effects. Phytochemical investigations on this plant led to organic acids, phthalides, polysaccharides, and other metabolites. Based on recent animal studies and clinical trials, RAS has been used in the treatment of gynecologic diseases, cardio-cerebrovascular disease, nervous system diseases, and nephrotic syndrome. In this review, the recent phytochemical and pharmacological studies, drug-drug interactions, clinical applications, and toxicity of RAS are summarized.

Quantitation of ursolic acid in human plasma by ultra performance liquid chromatography tandem mass spectrometry and its pharmacokinetic study.

Ursolic acid is a hydroxy pentacyclic triterpene, which proved to have sedation, anti-inflammatory, antibacterial, antiulcer and anti-cancer activities. An ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method with high selectivity, sensitivity and throughput has been established and validated for quantitation of total ursolic acid in human plasma. Plasma samples were pretreated by liquid-liquid extraction with ethyl acetate and were chromatographed by an ACQUITY UPLC BEH C(8) column (100 mm×2.1 mm, I.D., 1.7 μm) using mobile phase consisting of acetonitrile and 10 mM ammonium formate (90:10, v/v) at 0.2 mL/min. The duration of chromatography analysis was 3 min. The multiple reaction monitoring (MRM) was performed at m/z 455.1→455.0 for ursolic acid and m/z 469.3→425.2 for glycyrrhetinic acid (internal standard, IS) in the negative ion mode with electrospray ionization (ESI) source. The assay showed good linearity over the range of 10-5000 ng/mL for ursolic acid in human plasma with a lower limit of quantitation of 10 ng/mL. The mean extraction recovery was 73.2±4.5% and the matrix ion suppression ranged from -11.4% to -5.6%. The intra- and inter-day precisions were less than 7.0% and 7.2%, respectively, and the accuracy was within ±2.0%. Ursolic acid was stable during the analysis and the storage period. The validated method has been successfully applied to a pharmacokinetic study after intravenous infusion of Ursolic Acid Nano-liposomes to healthy volunteers.

Inhibition of Coix seed extract on fatty acid synthase, a novel target for anticancer activity

ETHNOPHARMACOLOGICAL RELEVANCE Coix seed has been traditionally used to treat cancers in folk medicine. AIM OF THE STUDY Study the anticancer action mechanism of Coix seed extract. MATERIALS AND METHODS After the treatment with Coix seed extract (10 microl/ml), the residual activity of fatty acid synthase (FAS) as overall reaction, beta-ketoacyl reduction, enoyl reduction, and acetyl acetyl coenzyme A (AcAcCoA) reduction was separately detected at 340 nm in the UV-190 spectrophotometer. After rats were administrated Coix seed extract (2.5, 5.0, and 10.0 ml/kg) intragastrically for 10 days consecutively, activities of FAS, malate dehydrogenase (MDH), lipid protein lipase (LPL), hepatic lipase (HL), triglyceride (TG), and glucose-6-phosphate dehydrogenase (G-6-PD) in the plasma, liver and fatty tissues were determined. RESULTS Experiments in vitro showed that the inhibition of Coix seed extract on FAS activity was significant and dose dependent, and two active sites inhibited were beta-ketoacyl reductases (KR) and enoyl reductase (ER). Experiments in vivo showed that Coix seed extract inhibited FAS activity in the liver, and elevated LPL and HL activity in the plasma, and effected G-6-PD activity. CONCLUSIONS The study supports that FAS is a novel target for anticancer activity, and provides a theoretical foundation for the wide application of Coix seed extract in traditional medicine.

An integrated metabonomic method for profiling of metabolic changes in carbon tetrachloride induced rat urine

Carbon tetrachloride (CCl(4)) is a well-known model compound for inducing chemical hepatic injury. This work characterizes the metabolism disorders of hepatotoxicity induced by CCl(4) in a Wistar rat model with a single dosage of 1 ml/kg. A seven-day long continuous collection of urine was performed in male rats in this experiment. Blood biochemistry and histopathology were examined to identify specific changes of liver hepatotoxicity. At the same time, an integrated analytical approach based on liquid chromatography coupled with mass spectrometry (LC-MS) was developed to map the metabolic response in urine. The current metabonomic approach based on LC-MS indicated 23 endogenous metabolites as biomarkers in urine associated with the hepatotoxicity induced by CCl(4). The underlying regulations of CCl(4)-perturbed metabolic pathways were discussed according to the identified metabolites. The present study proves the great potential of LC-MS based metabonomics in mapping metabolic response for toxicology.

Polymeric micelles for enhanced lymphatic drug delivery to treat metastatic tumors

Polymeric micelles have been proven to be a promising nano-sized system for drug delivery. Understanding its in vivo behaviors at the whole body, tissue and cellular levels is critical for translating this drug delivery system into clinical practice. In this study, the 14.5 nm micelles made of polyethylene glycol-phosphatidylethanolamine (PEG-PE) for delivery of doxorubicin and vinorelbine were investigated. Using confocal and two-photon microscopy imaging of live mice or tissue sections, we observed that after systemic administration, the fluorescently labeled PEG-PE micelles encapsulating doxorubicin migrated through blood vessels in entirety into the interstitial tissue, collected by lymphatic vessels, and accumulated in lymph nodes. Importantly, encapsulated drugs such as vinorelbine (Nanovin), preferentially accumulate in lymph nodes when compared to the free drugs. Moreover, the in vivo bioluminescent imaging showed that Nanovin significantly reduced lymph node metastasis rate (P<0.05) in 4 T1-luc2 murine breast tumor bearing mice. Finally, we observed that Nanovin enhanced antitumor activity against primary tumors and lung metastases while having low toxicity in various 4 T1 tumor models. This study suggests that PEG-PE micelle is a promising drug delivery system for the treatment of lymphatic metastases, and may also have important applications in other lymphatic system-related diseases.

Determination of strychnine and brucine in rat plasma using liquid chromatography electrospray ionization mass spectrometry.

A simple, sensitive and selective liquid chromatography-electrospray mass spectrometric (LC-ESI-MS) method was developed and validated for simultaneous determination of strychnine and brucine in rat plasma, using tacrine as the internal standard (IS). Sample preparation involved a liquid-liquid extraction of the analytes with n-hexane, dichloromethane and isopropanol (65:30:5, v/v/v) from 0.1mL of plasma. Chromatographic separation was carried out on a Waters C(18) column using a mobile phase of methanol-20mM ammonium formate-formic acid (32:68:0.68, v/v/v). Positive selected ion monitoring mode was used for detection of strychnine, brucine and the IS at m/z 335.2, m/z 395.2 and m/z 199.2, respectively. Linearity was obtained over the concentration range of 0.5-500ng/mL for strychnine and 0.1-100ng/mL for brucine. The lower limit of quantification was 0.5ng/mL and 0.1ng/mL for strychnine and brucine, respectively. The intra- and inter-day precision for both strychnine and brucine was less than 7.74%, and accuracy ranged from -4.38% to 2.21% at all QC levels. The method has been successfully applied to a pharmacokinetic study of processed Semen Strychni after oral administration to rats.

Effects of adlay seed oil on blood lipids and antioxidant capacity in hyperlipidemic rats

BACKGROUND Adlay (Coix lacryma-jobi L. subsp. ma-yuen (Romanet) T. Koyama (family Poaceae)) seed has been used as a dietary supplement for its therapeutic effects for thousands of years. This study was designed to investigate the effects of adlay seed oil, obtained by supercritical CO₂ extraction, on blood lipids and antioxidant capacity in hyperlipidemic rats. RESULTS Adlay seed oil could reduce the abdominal fat tissue and low-density lipoprotein concentration, and increase the total antioxidant capacity in hyperlipidemic rats. Adlay seed oil also significantly decreased the malondialdehyde content in serum, and increased serum total superoxide dismutase activity in hyperlipidemic rats. Therefore, the antioxidant mechanism might be related to the scavenging effects of adlay seed oil on reactive oxidative species, especially on the superoxide anion free radical. CONCLUSION The results showed that adlay seed oil had blood lipid-reducing and antioxidant effects, and could be used as a supplement in healthcare food and drugs for the prevention of chronic diseases (especially artherosclerosis and coronary artery disease).

A New Concept on Quality Marker for Quality Assessment and Process Control of Chinese Medicines

Abstract Chinese medicine (CM) is the most typical conventional therapy compared with any other traditional or alternative medicine systems. The active components of CMs are either primary or secondary metabolites generated by metabolic and biosynthetic enzymes in plants, protecting the plants from environmental stress. The characteristics of these metabolites are diverse, complicated and unique. In this paper, current approaches for quality assessment were extensively reviewed, a new concept of quality marker (Q-marker) was then proposed for CM quality assessment. Additionally, definition of the Q-marker, as well as the relevant methods, were discussed, on the basis of the biosynthetic pathways of secondary metabolites and source of biological active components. Study design of Q-marker is complex system for quality assessment and production process control of CM products with transitivity and traceability. Therefore, the system with characteristics of transmission and traceability is expected to be established for regulation of quality. Upon the concept which the transitivity and traceability in the quality assessment and production process control covered the entire process, such as raw materials, decoction slices, processing, extraction and production can be further enhanced. The transitivity and traceability will inevitably require close attention to “who, what, where, when, and why” details at each stage of Q-markers of CM production form raw materials to patent product. The establishing quality standards are enablers of many and various transitivity and traceability solutions, not a solution in them. It means that the transitivity and traceability system is readily link between products and across borders in quality. According to the thinking mode and methods of investigation on quality assessment of CM product, we focus on the entire process, in terms of safety and effectiveness and quality control. The standard preparation of CM or CM decoction is not only the basis for study of Q-marker, but also the basis for transmission and traceability of the quality of CM product.

Herb-drug Interactions Involving Drug Metabolizing Enzymes and Transporters

Herbal medicines and their active ingredients are widely used worldwide, and they have become an important part of clinical medicine. The combined use of herbs and drugs has increased the possibility of pharmacokinetic and pharmacodynamic interactions. Clinical studies have demonstrated that the combined use of herbs and drugs can enhance or attenuate the drug efficacy and toxicity. The herb-drug combinations may reduce a drug efficacy and lead to treatment failure when long-term administration. Case reports detailing serious clinical adverse reactions have promoted studies on the interactions between herbs and drugs. This review highlights recent knowledge to discuss herb-drug interactions involving metabolizing enzymes and drug transporters. Drug transporters are widely present in body and play an important role in the absorption, distribution, excretion and metabolism, efficacy, and toxicity of drugs. Investigation of transporters has developed rapidly since 1990s, the effects of many transporters on the pharmacokinetics of drugs and herb-drug interactions have been reported. Some concepts on drug transporters issued experimentally and clinically drug-drug and herb-drug interactions have applied in many studies. Methodology studies are very important for understanding the mechanism, considerations and evaluation of experiments and clinical studies on drug metabolizing enzymes and transporters in drug-drug interactions.

Improved HPLC method for doxorubicin quantification in rat plasma to study the pharmacokinetics of micelle‐encapsulated and liposome‐encapsulated doxorubicin formulations

An improved simple, rapid and accurate HPLC method for quantification of doxorubicin derived from micelle-encapsulated or liposome-encapsulated doxorubicin formulation in rat plasma was described. The mobile phase consisting of a mixture of methanol-water [containing 0.1% formic acid anhydrous and 0.1% ammonia solution (25%), pH 3.0], 60:40, was delivered at a flow rate of 1.0 mL/min. Sample preparation for micelle- or liposome-encapsulated doxorubicin in rat plasma were achieved directly by protein precipitation with acetonitrile. Doxorubicin and daunorubicin (internal standard, IS) were separated on a C(18) reversed-phase HPLC column and quantified by a fluoresence detection with an excitation wavelength of 475 nm and an emission wavelength of 580 nm. The linearity was obtained over the range of 5.0-1000.0 ng/mL and 1.0-200.0 microg/mL for doxorubicin and the lower limit of quantitation was 5.0 ng/mL. For each level of quality control samples, inter- and intra-assay precision was less than 9.6 and 5.1% (relative standard deviation), respectively, and percentage error was within +/-2.6%. The extraction recoveries of doxorubicin in the range of 10 ng/mL to 100 microg/mL in rat plasma were between 94.1 and 105.6%. This method was successfully applied to the pharmacokinetic study of doxorubicin formulations after i.v. administration to rats.