Analytical approaches for traditional chinese medicines exhibiting antineoplastic activity

Malinzi, a traditional medicinal plants: Comprehensive review of botany, medical application, chemical composition, and pharmacology

Malinzi is the dry ripe seed of Iris Lactea Pall. var. chinensis (Fisch.) Koidz and is a tradtional medicinal plant with significant development and utilization value. A total of 31 compounds from Malinzi have been reported, including flavonoids, quinones, oligostilbenes, and other constituents. Modern pharmacological studies have shown that Malinzi has good activities in anti-tumor, radio-sensitization, boost immunity, anti-oxidation, anti-fertility, and glucolipid metabolism. In this paper, by reviewing the domestic and foreign research literatures of Malinzi and summarizing its traditional uses, chemical constituents, and pharmacological activities, it is expected to provide theoretical reference for the subsequent in-depth research and application of Malinzi.

2-methylbenzoyl berbamine, a multi-targeted inhibitor, suppresses the growth of human osteosarcoma through disabling NF-κB, ERK and AKT signaling networks

Osteosarcoma is the most common malignant bone tumor in children and young adults, and it has a survival rate of only 60% with current cytotoxic chemotherapy combined with aggressive surgery. The aim of this study was to evaluate the therapeutic efficacy of the berbamine derivative 2-methylbenzoyl berbamine (BBD24) for osteosarcoma in vitro and in vivo. We used human osteosarcoma cell lines, primary osteosarcoma cells and mouse models to evaluate the inhibitory effects of BBD24 on osteosarcoma and to determine the molecular mechanism. Our results showed that BBD24 inhibited the growth of the human osteosarcoma cell lines HOS and MG63 in a time- and dose-dependent manner. BBD24 also exhibited significant inhibitory effects on primary osteosarcoma cells. In contrast, BBD24 did not affect normal blood cells under the same conditions. Treatment with BBD24 induced apoptosis, necrosis and autophagy in osteosarcoma cells. Western blot analysis revealed that BBD24 activated the caspase-dependent pathway and downregulated the NF-kB, AKT, and ERK pathways. Finally, BBD24 treatment induced a significant inhibitory effect on the growth of osteosarcoma in nude mice. Our findings indicate that BBD24 is a multitarget inhibitor and may represent a new type of anticancer agent for osteosarcoma treatment.

Salvia miltiorrhiza injection restores apoptosis of fibroblast-like synoviocytes cultured with serum from patients with rheumatoid arthritis

Salvia miltiorrhiza injection (SMI) is a water‑soluble agent, derived from Salvia miltiorrhiza (SM), that is traditionally used to treat cardiovascular and cerebrovascular diseases. Furthermore it has been demonstrated to possess the ability to induce apoptosis of tumor cells. However, it remains unclear whether SMI can induce apoptosis of rheumatoid arthritis (RA) fibroblast‑like synoviocytes (FLS), which are hyperplastic in RA due to defective apoptosis. There is also evidence that allogenic serum may be associated with the induction of apoptosis. The aim of the present study was to investigate the involvement of serum during SMI‑induced apoptosis in RA FLS. The results demonstrated that SMI could induce apoptosis of RA FLS, cultured with fetal bovine serum (FBS), in a dose‑dependent manner. In addition, SMI decreased the expression of nuclear factor‑κB in RA FLS nuclear extracts and inhibited the secretion of tumor necrosis factor‑α. Fas ligand expression was not detected in RA FLS, in either the presence or absence of SMI. The pro‑apoptotic genes B‑cell lymphoma 2 (Bcl‑2) associated X protein (Bax) and Fas, were shown to be upregulated following SMI stimulation, whereas the expression levels of the anti‑apoptotic gene Bcl‑2, were downregulated. Upon replacement of FBS with normal human serum, the apoptotic rate and Bax mRNA expression levels following SMI stimulation, were unchanged. However, culturing RA FLS with patient' serum (RPS), restored the apoptotic rate and Bax mRNA expression levels following SMI stimulation. There may be numerous mechanisms by which SMI inhibits RA FLS proliferation. The present study demonstrated that SMI can restore apoptosis of RA FLS cultured with RPS. These results indicate that SMI may have a potential role in the treatment of synovial hyperplasia of RA.

Combined therapeutic effects of vinblastine and Astragalus saponins in human colon cancer cells and tumor xenograft via inhibition of tumor growth and proangiogenic factors

Our previous study had demonstrated that Astragalus saponins (AST) could reduce the side effects of orthodox chemotherapeutic drugs, while concurrently promote antitumor activity. In the present study, we attempted to investigate the potential synergistic anticarcinogenic effects of AST and a vinca alkaloid vinblastine (VBL). Reduced expression of key proangiogenic and metastatic factors including VEGF, bFGF, metalloproteinase (MMP)-2, and MMP-9 was detected in VBL-treated colon cancer cells, with further downregulation by combined VBL/AST treatment. Subsequently, VBL or AST decreased LoVo cell invasiveness, with further reduction when the drugs were cotreated. Significant growth inhibition and cell cycle arrest at G2/M phase were achieved by either drug treatment with apparent synergistic effects. VBL-induced apoptosis was confirmed but found to be unrelated to induction of the novel apoptotic protein NSAID-activated gene 1. In vivo study in tumor xenograft indicates that combined VBL/AST treatment resulted in sustained regression of tumor growth, with attenuation of the neutropenic and anemic effects of VBL. In addition, downregulation of proangiogenic and proliferative factors was also visualized, with boosting effect by combined drug treatment. These findings have provided evidence that AST combined with adjuvant chemotherapeutics like VBL could alleviate cancer development through diversified modes of action, including the regulation of angiogenesis.

Pinocembrin: a novel natural compound with versatile pharmacological and biological activities

Pinocembrin (5,7-dihydroxyflavanone) is one of the primary flavonoids isolated from the variety of plants, mainly from Pinus heartwood, Eucalyptus, Populus, Euphorbia, and Sparattosperma leucanthum, in the diverse flora and purified by various chromatographic techniques. Pinocembrin is a major flavonoid molecule incorporated as multifunctional in the pharmaceutical industry. Its vast range of pharmacological activities has been well researched including antimicrobial, anti-inflammatory, antioxidant, and anticancer activities. In addition, pinocembrin can be used as neuroprotective against cerebral ischemic injury with a wide therapeutic time window, which may be attributed to its antiexcitotoxic effects. Pinocembrin exhibits pharmacological effects on almost all systems, and our aim is to review the pharmacological and therapeutic applications of pinocembrin with specific emphasis on mechanisms of actions. The design of new drugs based on the pharmacological effects of pinocembrin could be beneficial. This review suggests that pinocembrin is a potentially promising pharmacological candidate, but additional studies and clinical trials are required to determine its specific intracellular sites of action and derivative targets in order to fully understand the mechanism of its anti-inflammatory, anticancer, and apoptotic effects to further validate its medical applications.

Proteomic Changes Induced by Podophyllotoxin in Human Cervical Carcinoma HeLa Cells

Podophyllotoxin, a kind of lignan extracted from the Podophyllum plant, has been shown to inhibit the growth of various carcinoma cells. However, the molecular mechanism remains unclear. In this study, the inhibition of cell growth and changes in protein expression induced by podophyllotoxin were investigated in human cervical carcinoma HeLa cells. Our results demonstrate that Podophyllotoxin inhibits HeLa cell growth and induces apoptosis. By using proteomic techniques, seven proteins were found to be significantly regulated by podophyllotoxin compared to the untreated control; among them, four were down-regulated and three were up-regulated. All of the seven proteins were identified with peptide mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) after in-gel trypsin digestion. Five of these proteins are involved in protein metabolism, and the other two play roles in cell communication and signaling transduction pathways. It is suggested that the effect of podophyllotoxin on the growth of tumor cells is significantly related to the metabolism-associated proteins.

The determination of flavonoids in Wikstroemia indica C. A. Mey. by liquid chromatography with photo-diode array detection and negative electrospray ionization tandem mass spectrometry

RATIONALE

Flavonoids in the medicinal plant Wikstroemia indica C. A. Mey. are present in trace amounts and found in complex matrices. An efficient and sensitive method is necessary for the rapid identification of such biomolecules.

METHODS

Flavonoids were extracted with methanol via ultrasonic-assisted extraction and analyzed by liquid chromatography with photo-diode array detection and tandem mass spectrometry. The extract was analyzed and compounds were identified using negative electrospray ionization data-dependent tandem mass spectrometry.

RESULTS

The results confirmed the presence of three flavonoid compounds, seven biflavonoid compounds, and one coumarin-like compound, daphnoretin, in the extracts of different plant parts of W. indica. The method detection limit was evaluated down to 5 µg/g using kaempfol as a reference standard.

CONCLUSIONS

The proposed method offers a rapid and reliable analysis for the determination of flavonoids in medicinal plants.

CaMKII γ, a critical regulator of CML stem/progenitor cells, is a target of the natural product berbamine

Bcr-Abl tyrosine kinase inhibitors (TKIs) have been a remarkable success for the treatment of Ph(+) chronic myeloid leukemia (CML). However, a significant proportion of patients treated with TKIs develop resistance because of leukemia stem cells (LSCs) and T315I mutant Bcr-Abl. Here we describe the unknown activity of the natural product berbamine that efficiently eradicates LSCs and T315I mutant Bcr-Abl clones. Unexpectedly, we identify CaMKII γ as a specific and critical target of berbamine for its antileukemia activity. Berbamine specifically binds to the ATP-binding pocket of CaMKII γ, inhibits its phosphorylation and triggers apoptosis of leukemia cells. More importantly, CaMKII γ is highly activated in LSCs but not in normal hematopoietic stem cells and coactivates LSC-related β-catenin and Stat3 signaling networks. The identification of CaMKII γ as a specific target of berbamine and as a critical molecular switch regulating multiple LSC-related signaling pathways can explain the unique antileukemia activity of berbamine. These findings also suggest that berbamine may be the first ATP-competitive inhibitor of CaMKII γ, and potentially, can serve as a new type of molecular targeted agent through inhibition of the CaMKII γ activity for treatment of leukemia.

INTERACTION OF EMODIN WITH DNA BASES: A DENSITY FUNCTIONAL THEORY

In this study, we present work on the physicochemical interaction between the anticancer drug molecule Emodin (ED) and DNA. Comprehending the physicochemical properties of this drug besides the mechanism by which it interacts with DNA should eventually permit the rational design of novel anticancer or antiviral drugs. The final purpose is the clarification of this novel class of drugs as potential pharmaceutical agents. The properties of the isolated intercalator ED and its stacking interactions with adenine⋯thymine (AT) and guanine⋯cytosine (GC) (nucleic acid base pairs) in face-to-face and face-to-back models were studied by means of the density functional tightbinding (DFTB) method. This method was an approximate version of the density functional theory (DFT) method and it includes London dispersion energy. The molecular modeling of the complex formed between ED and DNA indicated that this complex was capable of contributing to the formation of a constant intercalation site. The results exhibit that ED changes affect DNA structure with reference to bond lengths, bond angles, torsion angles, and charges.

Analysis of anticancer drugs: a review

In the last decades, the number of patients receiving chemotherapy has considerably increased. Given the toxicity of cytotoxic agents to humans (not only for patients but also for healthcare professionals), the development of reliable analytical methods to analyse these compounds became necessary. From the discovery of new substances to patient administration, all pharmaceutical fields are concerned with the analysis of cytotoxic drugs. In this review, the use of methods to analyse cytotoxic agents in various matrices, such as pharmaceutical formulations and biological and environmental samples, is discussed. Thus, an overview of reported analytical methods for the determination of the most commonly used anticancer drugs is given.

Investigation into omacetaxine solution stability for in vitro study

Omacetaxine is a natural product extract originating from Chinese medicine and finding therapeutic use as a potent myelosuppressive agent in leukemia. When planning in vitro cell biology experiments to assess omacetaxine activity against primary leukemic stem cells, it became apparent that the literature rarely describes the in vitro stability of the molecule, although accessible chromatographic methods have been published. Clearly whole organisms vs their component cells will differ in the way in which they handle xenobiotics, with the latter more dependent on physiochemical parameters such as pH and temperature in the absence of active metabolism or excretion. This could impact on the cells' experience of drug in culture. We therefore report here on examination of a modified, high-performance liquid chromatography (HPLC) method with assessment of degradant production from a 72 h solution stability study, clearly demonstrating that omacetaxine is highly stable in representative cell culture conditions (37 °C, neutral pH) and persists for many days in marked contrast to its short-half life in vivo.

High throughput identification of components from traditional Chinese medicine herbs by utilizing graphene or graphene oxide as MALDI-TOF-MS matrix

In this work, graphene or graphene oxide was utilized, for the first time, to identify small molecular components from traditional Chinese medicine (TCM) herbs, by acting as matrix of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Due to the large surface area of graphene or graphene oxide, the analytes were trapped tightly to the matrix, which avoids the contamination of the ion source and vacuum system. Besides, their excellent electronic, thermal and mechanical properties make them desired matrices for MALDI-TOF-MS. Stable analysis was achieved with no background inference even at the concentration of 100 nM. Moreover, the limit of detection (LOD) could be greatly lowered by utilizing graphene or graphene oxide as a pre-enrichment adsorbent. In summary, the promoted MALDI-TOF-MS methodology was demonstrated to be simple, sensitive, fast, cost effective and, most importantly, high throughput.

Salvianolic Acid B, a potential chemopreventive agent, for head and neck squamous cell cancer

Head and neck squamous cell cancer (HNSCC) is one of the top ten cancers in the United States. The survival rate of HNSCC has only marginally improved over the last two decades. In addition, African-American men bear a disproportionate burden of this preventable disease. Therefore, a critical challenge of preventive health approaches is warranted. Salvianolic acid B (Sal-B) isolated from Salvia miltiorrhiza Bge, which is a well-know Chinese medicines has been safely used to treat and prevent aging diseases for thousand of years. Recently, the anticancer properties of Sal-B have received more attention. Sal-B significantly inhibits or delays the growth of HNSCC in both cultured HNSCC cells and HNSCC xenograft animal models. The following anticancer mechanisms have been proposed: the inhibition of COX-2/PGE-2 pathway, the promotion of apoptosis, and the modulation of angiogenesis. In conclusion, Sal-B is a potential HNSCC chemopreventive agent working through antioxidation and anti-inflammation mechanisms.

Ultrasonic extraction and HPLC determination of anthraquinones, aloe-emodine, emodine, rheine, chrysophanol and physcione, in roots of Polygoni multiflori

INTRODUCTION

Polygoni multiflori, one of traditional Chinese herbal medicines for the treatment of various diseases commonly associated with aging, is known to contain active anthraquinone ingredients. However, the content of the anthraquinones varies among P. multiflori samples with collection season and sites. Thus, simple, reliable and accurate analytical methods for determining of anthraquinones in P. multiflori products are needed for the quality control and pharmacological studies.

OBJECTIVE

To develop an HPLC method for the simultaneous determination of five anthraquinones, aloe-emodine, rheine, emodine, chrysophanol and physcione, in the roots of P. multiflori.

METHODOLOGY

Anthraquinones were extracted from the roots of P. multiflori using aqueous alcohol solutions or hot water under ultrasonication. Separation and quantitation of anthraquinones was accomplished using a reversed-phase C18 column with the mobile phase of methanol-water-phosphoric acid (600:400:1), and the detection wavelength of 254 nm.

RESULTS

Seventy per cent aqueous ethanol showed the highest extraction efficiency for anthraquinones from roots of P. multiflori when compared with four other extraction solvents tested. All calibration curves were linear over the concentration range tested with the square of correlation coefficients >0.999. The detection limits (S/N = 3) were 0.89, 1.1, 1.6, 1.7 and 2.0 ng for chrysophanol, aloe-emodine, rheine, emodine and physcione, respectively. Emodine and physcione were found in the samples tested at concentrations of 0.341 and 0.197 mg/g, respectively.

CONCLUSION

The described HPLC methods are simple, accurate and selective techniques for separation and quantification of anthraquinones in roots of P. multiflori and other plant samples.

Probing the binding sites and the effect of berbamine on the structure of bovine serum albumin

Berbamine, a naturally occurring isoquinoline alkaloid extracted from Berberis sp., is the active constituent of some Chinese herbal medicines and exhibits a variety of pharmacological activities. The effects of berbamine on the structure of bovine serum albumin (BSA) were investigated by circular dichroism, fluorescence and absorption spectroscopy under physiological conditions. Berbamine caused a static quenching of the intrinsic fluorescence of BSA, and the quenching data were analyzed by application of the Stern-Volmer equation. There was a single primary berbamine-binding site on BSA with a binding constant of 2.577x10(4)Lmol(-1) at 298K. The thermodynamic parameters, enthalpy change (DeltaH(0)) and entropy change (DeltaS(0)) for the reaction were -76.5kJmol(-1) and -173.4Jmol(-1)K(-1) according to the van't Hoff equation. The results showed that the hydrogen bond and van der Waals interaction were the predominant forces in the binding process. Competitive experiments revealed a displacement of warfarin by berbamine, indicating that the binding site was located at Drug sites I. The distance r between the donor (BSA) and the acceptor (berbamine) was obtained according to the Förster non-radiation energy transfer theory. The results of three-dimensional fluorescence spectra, UV-vis absorption difference spectra and circular dichroism of BSA in the presence of berbamine showed that the conformation of BSA was changed. The results provide a quantitative understanding of the effect of berbamine on the structure of bovine serum albumin, providing a useful guideline for further drug design.

Determination of camptothecins in DMSO extracts of Nothapodytes foetida by direct injection capillary electrophoresis

A rapid capillary electrophoresis procedure was developed for determining the anti-cancer components, camptothecins, in Nothapodytes foetida. The hydrophobic compound was extracted from plant tissue (ca. 1 mL of DMSO for 100 mg of dried plant tissue) with a water-miscible organic solvent, DMSO, at elevated temperature (60 degrees C). The extract was directly injected into the separation capillary (untreated fused silica, 34 cm in length, 75 microm i.d.) and analysed in MEKC mode (369 nm). Within 5 min of migration, camptothecins were successfully separated and quantified by adding organic modifiers to the running buffer (20% DMSO, 90 mm SDS in 10 mm borate buffer, pH 8.60). The linear dynamic range for camptothecin was from 5 to 400 microg/mL. This method was proven to be very suitable for monitoring the amount of camptothecins during the cultivation of the medicinal plant.

Studies on alkaloids binding to GC-rich human survivin promoter DNA using positive and negative ion electrospray ionization mass spectrometry

Electrospray ionization mass spectrometry (ESI-MS) was used to investigate the binding of 13 alkaloids to two GC-rich DNA duplexes which are critical sequences in human survivin promoter. Negative ion ESI-MS was first applied to screen the binding of the alkaloids to the duplexes. Six alkaloids (including berberine, jatrorrhizine, palmatine, reserpine, berbamine, and tetrandrine) show complexation with the target DNA sequences. Relative binding affinities were estimated from the negative ion ESI data, and the alkaloids show a binding preference to the duplex with higher GC content. Positive ion ESI mass spectra of the complexes were also recorded and compared with those obtained in negative ion mode. Only the 1 : 1 complex with berbamine was observed with lower abundance in the positive ion mass spectrum while complexes with the other alkaloids were absolutely absent. Collision-induced dissociation (CID) experiments indicate that the complexes with the protoberberine alkaloids (berberine, jatrorrhizine, and palmatine) dissociate via base loss and covalent cleavage. In contrast, product ion spectra of the complexes with the alkaloids reserpine, berbamine, and tetrandrine show the predominant loss of a neutral alkaloid molecule, accompanied by base loss and covalent cleavage to a lesser extent. A comparison of the gas-phase behaviors of complexes with the alkaloids to those with the traditional DNA binders has suggested an intercalative binding mode of these alkaloids to the target DNA duplexes.

Simultaneous determination of anthraquinones in radix Polygoni multiflori by capillary gas chromatography coupled with flame ionization and mass spectrometric detection

A rapid, accurate and reliable analytical method was developed for the simultaneous determination of five major anthraquinones, aloe-emodin, chrysophanol, emodin, physcion, and rhein, in radix Polygoni multiflori, a traditional Chinese herbal medicine. The method comprises a fast ultrasonic extraction with methanol and derivatization with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA)+1% trimethylchlorosilane (TMCS) followed by capillary gas chromatographic (GC) separation. The effect of reaction time on the derivatization of anthraquinones was examined. A baseline separation of the anthraquinone and internal standard derivatives was achieved in 15min. The detection limits range from 0.22 to 0.60microg/mL for the five anthraquinones. The calibration curves are linear over the concentration range studied (from the detection limits to 40.0microg/mL) with the squares of correlation coefficients, R2, greater than 0.998. The developed method was successfully applied to the simultaneous determination of anthraquinones in radix P. multiflori samples. The peak identification was confirmed using GC-MS. The contents of anthraquinones in radix P. multiflori samples studied were 27.41, 289.6, 64.22, 202.1, 288.6microg/g for chrysophanol, emodin, aloe-emodin, physcion, rhein, respectively. All relative standard deviations are less than 3.2%. The recoveries range from 80.2% to 119.3% for the five analytes. To the authors' best knowledge, this is the first GC method reported for the simultaneous determination of the five anthraquinones in radix P. multiflori.

Development of an improved liquid phase microextraction technique and its application in the analysis of flumetsulam and its two analogous herbicides in soil

An improved liquid phase microextraction (LPME) technique has been developed. As part of this technique, analytes were extracted into an extractant microdrop which was laid on the cone-shaped bottom of a PCR tube (polychloroprene rubber tube) but not at the needle tip of a microsyringe, and the sample vial and PCR tube were horizontally placed so that the extractant was not affected by the force of vertical orientation (gravity and floating force). The stability of the extractant microdrop increased greatly, and the selection of extractant was extended. In this work, flumetsulam and its two analogous herbicides were chosen as model analytes in investigating the feasibility of the new pretreatment method by coupling it to high-performance liquid chromatography (HPLC). Under the optimized experimental conditions, the linear range and the limits of detection (S/N = 3) were 0.01-5 microg/mL (r = 0.9997) and 0.8 ng/mL for flumetsulam, 0.002-5 microg/mL (r = 0.9994) and 0.5 ng/mL for analogue 1, and 0.002-1 microg/mL (r = 0.9993) and 0.5 ng/mL for analog 2, respectively. The inter- and intraday reproducibilities (RSD) were below 5.3 and 4.5%, respectively. Good recoveries that ranged from 79.4 to 115.0% were obtained in the analysis of real soil samples. The extraction efficiency of the improved method was 4-8 times higher than that of the conventional liquid phase microextraction method. The novel, simple, rapid, sensitive technique is very suitable for extraction of apolar and medium polar analyte in complex environmental samples.

Molecular mechanism of emodin action: transition from laxative ingredient to an antitumor agent

Anthraquinones represent a large family of compounds having diverse biological properties. Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is a naturally occurring anthraquinone present in the roots and barks of numerous plants, molds, and lichens, and an active ingredient of various Chinese herbs. Earlier studies have documented mutagenic/genotoxic effects of emodin, mainly in bacterial system. Emodin, first assigned to be a specific inhibitor of the protein tyrosine kinase p65lck, has now a number of cellular targets interacting with it. Its inhibitory effect on mammalian cell cycle modulation in specific oncogene overexpressed cells formed the basis of using this compound as an anticancer agent. Identification of apoptosis as a mechanism of elimination of cells treated with cytotoxic agents initiated new studies deciphering the mechanism of apoptosis induced by emodin. At present, its role in combination chemotherapy with standard drugs to reduce toxicity and to enhance efficacy is pursued vigorously. Its additional inhibitory effects on angiogenic and metastasis regulatory processes make emodin a sensible candidate as a specific blocker of tumor-associated events. Additionally, because of its quinone structure, emodin may interfere with electron transport process and in altering cellular redox status, which may account for its cytotoxic properties in different systems. However, there is no documentation available which reviews the biological activities of emodin, in particular, its growth inhibitory effects. This review is an attempt to analyze the biological properties of emodin, a molecule offering a broad therapeutic window, which in future may become a member of anticancer armamentarium.

Recent developments in sample preparation techniques for chromatography analysis of traditional Chinese medicines

Traditional Chinese medicines (TCMs) have a long history dating back thousands of years. Recently, there has been increasing interest worldwide in the use of TCMs for the prevention and treatment of various illnesses. In China, a large number of analytical tools, especially chromatographic techniques have been used to analyze the constituents of TCMs in order to control their quality and discover new bioactive compounds. In this paper, recent developments in sample preparation techniques for the extraction, clean-up, and concentration of analytes from TCMs are compared. These techniques include headspace solid-phase microextraction (HS-SPME), headspace liquid-phase microextraction (HS-LPME), microwave-assisted extraction (MAE), supercritical-fluid extraction (SFE), pressurized-liquid extraction (PLE), and microwave distillation (MD).

Simultaneous determination of eight active components in Chinese medicine ‘YIQING’ capsule using high-performance liquid chromatography

An effective, accurate and reliable method for the simultaneous separation and determination of eight active components (berberine, aloe-emodin, rhein, emodin, chrysophanol, baicalin, baicalein and wogonin) in Chinese medicine 'YIQING' capsule was developed using reverse phase high-performance liquid chromatography (RP-HPLC) coupled with diode array detection. The chromatographic separation was performed on a Lichrospher C18 column (250 mm x 4.6 mm i.d. with 5.0 microm particle size) with a simple linear gradient elution programme. Due to the different UV characteristic of these components, three detection wavelengths were utilized for the quantitative analysis (UV wavelength 254 nm for anthraquinone derivatives, 278 nm for flavones compounds, and 345 nm for protoberberine alkaloids, respectively). Excellent linear behaviors over the investigated concentration ranges were observed with the values of R2 higher than 0.99 for all the analytes. The recoveries, measured at three concentration levels, varied from 94.9% to 105.3%. The validated method was successfully applied to the simultaneously determination of these active components in 'YIQING' capsules from different production batches.

Electrochemical studies of the interaction of the anticancer herbal drug emodin with DNA

The interaction between anticancer herbal drug emodin and DNA was studied with differential pulse voltammetry (DPV) and cyclic voltammetry (CV) at the bare or DNA modified GCE and ultraviolet-visible (UV) spectra. The DPV of emodin showed that peak potentials shifted to more positive value and peak currents decreased with the addition of DNA. UV spectra exhibited that the absorption of emodin at about 440nm decreased with red shift. The results showed that the herbal drug emodin interacted with DNA by intercalating into the double helix of DNA. Under our experiment conditions, the decrease of peak current was proportional to DNA concentration, which can be applied to determining DNA concentration. The combining constant (beta) and combing number (m) of DNA-mEM were determined too.