Nonaqueous capillary electrophoresis coupled with laser-induced native fluorescence detection for the analysis of berberine, palmatine, and jatrorrhizine in Chinese herbal medicines

Fluorescence enhancement of flavonoids and its application in ingredient determination for some traditional Chinese medicines by CE-LIF

Flavonoids are widely used in the treatment of various diseases due to their antioxidant, anti-inflammatory, anticancer and antiviral properties. Fluorescence detection is rarely applied for the determination of flavonoids because of their weak fluorescence. In this work, a method of fluorescence enhancement of flavonoids was firstly introduced by using sodium acetate for flavonoid derivatization. The study discovered that flavonoids, with a hydroxyl at the C3 position, had the ability to emit strong fluorescence after derivatization. Five flavonoids, kaempferide, galangin, isorhamnetin, kaempferol and quercetin, having a special structure, were selected, derivatized and analyzed by capillary electrophoresis with laser-induced fluorescence detection. Under the optimal conditions, the five flavonoids could be completely separated within 3 minutes. Good linear relationships were obtained for all analytes and the limits of detection for the five flavonoids were in the range of 1.18-4.67 × 10^-7 mol L^-1. Finally, the method was applied to the determination of flavonoids in five traditional Chinese medicines: aster, chamomile, galangal, tangerine peel and cacumen biotae. Flavonoids were successfully found in all these medicines by the developed method. The recoveries were in the range of 84.2-111%. The method developed in this study was fast, sensitive and reliable for the determination of flavonoids.

Development of a multianalytical strategy for detection of frauds in Coleus forskohlii supplements

A new multianalytical methodology based on gas chromatography (GC) and liquid chromatography (LC) coupled to mass spectrometry (MS) has been proposed to evaluate frauds affecting the composition of Coleus forskohlii root supplements (FKS). After optimization and validation of chromatographic methods, 24 FKS were analyzed. Forskolin, their main bioactive component, was only found in 50% of the FKS evaluated (in the 0.032-17.1% range), with 27% of these supplements showing concentrations of this bioactive lower than those declared in their labels. Application of this methodology also proved to be successful for the detection of frauds regarding the replacement of C. forskohlii by other vegetable sources (green tea, soy leaves and a plant of the Berberidaceae family) in 17% of supplements analyzed. A study on stability of forskolin under accelerated conditions allowed to rule out its degradation as responsible for the lack of this bioactive or other natural constituents in 25% of FKS evaluated. It can be concluded that the multianalytical methodology here developed is an advantageous alternative to address the wide diversity of frauds affecting these supplements.

Potential and applications of capillary electrophoresis for analyzing traditional Chinese medicine: a critical review

Capillary electrophoresis (CE) presents a promising possibility for analyzing traditional Chinese medicine (TCM) due to its low reagent consumption, high analysis speed, and enhanced efficiency. Herein we review the employment of CE for analyzing the effective components in TCM and identifying TCM via a fingerprint. Furthermore, we discuss the application of state-of-the-art capillary electrophoresis modes for screening enzyme inhibitors and investigating the interactions between TCM and plasma proteins. The review concludes with recommendations for future studies and improvements in this field of research. The general development trend identified in this review indicates that the application of CE has significantly improved TCM assay performance.

Application of Capillary Electrophoresis to the Analysis of Bioactive Compounds in Herbal Raw Materials

The article is a summary of scientific reports from the last 16 years (2005-2021) on the use of capillary electrophoresis to analyze polyphenolic compounds, coumarins, amino acids, and alkaloids in teas or different parts of plants used to prepare aqueous infusions, commonly known as "tea" or decoctions. This literature review is based on PRISMA guidelines and articles selected in base of criteria carried out using PICOS (Population, Intervention, Comparison, Outcome, Study type). The analysis showed that over 60% of articles included in this manuscript comes from China. The literature review shows that for the selective electrophoretic separation of polyphenolic and flavonoid compounds, the most frequently used capillary electromigration technique is capillary electrophoresis with ultraviolet detection. Nevertheless, the use of capillary electrophoresis-mass spectrometry allows for the sensitive determination of analytes with a lower limit of detection and gives hope for routine use in the analysis of functional foods. Moreover, using the modifications in electrochemical techniques allows methods sensitivity reduction along with the reduction of analysis time.

Naturally occurring proteinaceous nanoparticles in Coptidis Rhizoma extract act as concentration-dependent carriers that facilitate berberine absorption

Pharmacological activities of some natural products diminish and even disappear after purification. In this study, we explored the mechanisms underlying the decrease of acute oral toxicity of Coptidis Rhizoma extract after purification. The water solubility, in vitro absorption, and plasma exposure of berberine (the major active compound) in the Coptidis Rhizoma extract were much better than those of pure berberine. Scanning electron microscopy, laser scanning confocal microscopy (LSCM), and dynamic light scattering experiments confirmed that nanoparticles attached to very fine precipitates existed in the aqueous extract solution. The LSCM experiment showed that the precipitates were absorbed with the particles by the mouse intestine. High-speed centrifugation of the extract could not remove the nanoparticles and did not influence plasma exposure or acute oral toxicity. However, after extract dilution, the attached precipitates vanished, although the nanoparticles were preserved, and there were no differences in the acute oral toxicity and plasma exposure between the extract and pure berberine. The nanoparticles were then purified and identified as proteinaceous. Furthermore, they could absorb co-dissolved berberine. Our results indicate that naturally occurring proteinaceous nanoparticles in Coptidis Rhizoma extract act as concentration-dependent carriers that facilitate berberine absorption. These findings should inspire related studies in other natural products.

Discrimination of Rhizoma Gastrodiae (Tianma) using 3D synchronous fluorescence spectroscopy coupled with principal component analysis

Rhizoma Gastrodiae (Tianma) of different variants and different geographical origins has vital difference in quality and physiological efficacy. This paper focused on the classification and identification of Tianma of six types (two variants from three different geographical origins) using three dimensional synchronous fluorescence spectroscopy (3D-SFS) coupled with principal component analysis (PCA). 3D-SF spectra of aqueous extracts, which were obtained from Tianma of the six types, were measured by a LS-50B luminescence spectrofluorometer. The experimental results showed that the characteristic fluorescent spectral regions of the 3D-SF spectra were similar, while the intensities of characteristic regions are different significantly. Coupled these differences in peak intensities with PCA, Tianma of six types could be discriminated successfully. In conclusion, 3D-SFS coupled with PCA, which has such advantages as effective, specific, rapid, non-polluting, has an edge for discrimination of the similar Chinese herbal medicine. And the proposed methodology is a useful tool to classify and identify Tianma of different variants and different geographical origins.

Enhancement of native fluorescence intensity of berberine by (2-hydroxypropyl)-β-cyclodextrin in capillary electrophoresis coupled by laser-induced fluorescence detection: application to quality control of medicinal plants

A sensitive method for the determination of berberine, a plant alkaloid, was developed by capillary electrophoresis coupled with laser induced fluorescence detection. With the addition of (2-hydroxypropyl)-β-cyclodextrin (2-HP-β-CD) to the separation electrolyte, the low fluorescence signal intensity of berberine in aqueous medium was enhanced considerably by 162 fold. The optimal background electrolyte was selected as 20mM acetic acid, 35mM 2-HP-β-CD, and 20% methanol at pH 5. The limit of detection of the method for berberine was 15.7ng/mL. The intra and interday repeatabilities of corrected peak areas as RDSs were 1.83% and 3.75%, respectively. The developed method was successfully applied for the determination of berberine contents in Chinese medicinal plants and herbal supplemental tablets.

Analysis of four alkaloids of Coptis chinensis in rat plasma by high performance liquid chromatography with electrochemical detection

A sensitive and precise high performance liquid chromatography (HPLC)-electrochemical detection (ECD) method has been developed for the simultaneous determination of four isoquinoline alkaloids including berberine, jatrorrhizine, coptisine and palmatine in Chinese medicine Coptis chinensis. The typical HPLC analysis was performed on WondaSil(®) C18-WR column (250×4.6 mm, 5 μm) with the mobile phase comprising 40 mM phosphate buffer (pH 7.0)-acetonitrile (40:60, v/v) at the flow rate of 0.8 mL min(-1). The electrochemical detection employed a three electrode system with a bare glassy carbon electrode at +1.3 V versus the Ag/AgCl reference electrode. The limits of detection (LODs) of four alkaloids ranged from 0.01 to 0.03 μmol L(-1) and the LOD of berberine was 80 times lower than LOD obtained by UV detection. The rat plasma samples were assayed after oral administration of the traditional Chinese medicine Coptis chinensis by the proposed HPLC-ECD method. The recoveries of this method were ranging from 88.0 to 116%, with the relative standard deviation lower than 3.1% for intra-day precision and 5.7% for inter-day precision. These results show that HPLC-ECD is a useful tool for the quality control of herbal medicine Coptis chinensis and also for pharmacokinetic studies.

Determination of protoberberine alkaloids in Rhizoma Coptidis by ERETIC ¹H NMR method

An alternative quantification approach called ERETIC (Electronic REference To access In vivo Concentrations) utilizing electronic reference-based proton nuclear magnetic resonance (¹H NMR) spectroscopy techniques has been successfully introduced in our present study to simultaneously determine the contents of five major active protoberberine alkaloids (berberine, coptisine, jatrorrhizine, palmatine and epiberberine) in Rhizoma Coptidis, one of the most commonly used traditional Chinese medicines (TCM). The NMR experimental conditions including deuterated solvent, relaxation delay time, and ERETIC transmitter power level were optimized, and the developed method was validated in terms of precision, reproducibility, stability, accuracy, recovery, and limit of quantification (LOQ). The recoveries of the five tested alkaloids ranged between 89.94 and 97.72% for berberine, 90.87 and 100.05% for coptisine, 98.35 and 107.57% for jatrorrhizine, 95.37 and 101.26% for palmatine, and 93.18 and 98.00% for epiberberine, respectively, and LOQ was 0.1 mM for berberine. The high universality, accuracy, reproducibility, and efficiency of the ERETIC method demonstrated in this work suggest that this method could serve as a highly potential quantification alternative for quality assessment of TCM.

Simultaneous determination of iridoid glycosides and flavanoids in Lamionphlomis rotate and its herbal preparation by a simple and rapid capillary zone electrophoresis method

Iridoid glycosides and flavanoids are two main effective components of Lamiophlomis rotata (Benth.) kudo. However, there is no method for simultaneous analysis of iridoid glycosides and flavanoids in L. rotata and its pharmaceutical preparations. A simple and rapid capillary zone electrophoresis (CZE) method was developed and validated for simultaneous determination of two iridoid glycosides (8-O-acetylshanzhiside methylester and 8-deoxyshanzhiside) and three flavanoids (apigenin, quercetin and luteolin) in L. rotata. Operational variables, such as the voltage, buffer concentration and pH were optimized, the final optimum separation condition was 10 mM sodium tetraborate-20 mM NaH(2) PO(4) (pH 8.5)-15% (v/v) methanol, 238 nm UV detection, 18 kV applied voltage. The linearity and the recovery of the proposed method were very satisfactory (correlation coefficients were 0.9994-0.9998 and the recoveries were 94.5-108.8% for the analytes) and the method allowed analytes in real samples to be determined within 9 min. The proposed CZE method can be used for quality control of iridoid glycosides and flavanoids in L. rotata and its herbal preparation.

Bioanalytical applications of capillary electrophoresis with laser-induced native fluorescence detection

In this article we describe recent developments and applications of capillary electrophoresis (CE) coupled with laser-induced native fluorescence (LINF) detection in the analysis of biological, pharmaceutical and environmental samples. Compared with traditional UV absorbance detection used in CE, the LINF technique can greatly improve the concentration sensitivity of CE without the need for derivatization; the only requirement being that the analyte must have native fluorescence. Instrumentation and laser sources used in CE–LINF are summarized and specific applications of CE–LINF to small-biomolecule analysis, profiling of human biofluids, detection of native fluorescent peptides and proteins, single-cell analysis and the use of online sample preconcentration methods are also reviewed in detail.

Pulsatilla decoction and its active ingredients inhibit secretion of NO, ET-1, TNF-alpha, and IL-1 alpha in LPS-induced rat intestinal microvascular endothelial cells

To investigate the pharmacological mechanism of the traditional Chinese medicine, Pulsatilla decoction (PD), the levels of nitric oxide (NO), endothelin-1 (ET-1), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1 alpha (IL-1 alpha) secreted by cultured rat intestinal microvascular endothelial cells (RIMECs) were determined after treatment with PD and its seven active ingredients, namely anemoside B(4), anemonin, berberine, jatrorrhizine, palmatine, aesculin, and esculetin. RIMECs were challenged with lipopolysaccharide (LPS) at 1 microg ml(-1) for 3 h and then treated with PD at 1, 5, and 10 mg ml(-1) and its seven ingredients at 1, 5, and 10 microg ml(-1) for 21 h, respectively. The results revealed that PD, anemonin, berberine, and esculetin inhibited the production of NO; PD, anemonin, and esculetin inhibited the secretion of ET-1; PD, anemoside B(4), berberine, jatrorrhizine, and aesculin downregulated TNF-alpha expression; PD, anemoside B(4), berberine, and palmatine decreased the content of IL-1 alpha. It showed that PD and its active ingredients could significantly inhibit the secretion of NO, ET-1, TNF-alpha, and IL-1 alpha in LPS-induced RIMECs and suggested they would reduce inflammatory response via these cytokines.

Study on the antiendotoxin action of Pulsatillae Decoction using an Affymetrix rat genome array

A high-throughput and efficient Affymetrix rat genome array was used to investigate the pharmacological mechanism of the traditional Chinese medicine, Pulsatillae Decoction (PD), used for the treatment of diseases induced by lipopolysaccharide (LPS). Rat intestinal microvascular endothelial cells (RIMECs) were challenged with 1mug/ml LPS for 3h, and then treated with PD at a concentration of 1mg/ml for 24h. Total RNA from each treatment group was extracted from cultured RIMECs for detection by the Affymetrix Rat Genome 230 2.0 Array. The results showed that 36 genes were upregulated and 33 genes were downregulated in the LPS group vs. the blank control group; 566 genes were upregulated and 12 genes were downregulated in the PD-treated group vs. the LPS group; and 93 genes were upregulated and 29 genes were downregulated in the PD-treated group vs. the blank control group. The analysis of these data suggested that PD specifically and effectively reduce damage induced by LPS, and improved physiological and biochemical responses to counteract the effects of LPS.

Determination of berberine in human plasma by liquid chromatography-electrospray ionization-mass spectrometry

A liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method for the determination of berberine in human plasma using chlorobenzylidine as the internal standard (IS) has been developed and validated. The plasma samples were prepared by LLE and the analytes were chromatographically separated on a Hanbon Lichrospher 5-C18 HPLC column under gradient elution with a mobile phase consisted of acetonitrile and 10mm ammonium acetate buffer containing 0.1% formic acid. Berberine was determined with electrospray ionisation-mass spectrometry (ESI-MS). LC-ESI-MS was performed in the selected-ion monitoring (SIM) mode using target ions at M(+)m/z 336.1 for berberine and M(+)m/z 464.1 for the IS. Calibration curve was linear over the range of 0.020-3.0 ng/ml. The lower limit of quantification (LLOQ) was 0.020 ng/ml. The intra- and inter-run variability values were less than 6.7 and 7.7%, respectively. The method has been successfully applied to determine the plasma concentration of berberine in healthy Chinese volunteers.

Simultaneous determination of eight components in Radix Tinosporae by high-performance liquid chromatography coupled with diode array detector and electrospray tandem mass spectrometry

High-performance liquid chromatography (HPLC) coupled with electrospray tandem mass spectrometry (ESI-MS-MS) and diode array detection (DAD) was used to identify and simultaneously determine eight major ingredients in Radix Tinosporae. The assay was performed on a Diamonsil C(18) analytical column with a gradient solvent system of A (water containing 0.2% formic acid, 20mM ammonium acetate) and B (methanol/acetonitrile=1/1, v/v). The 217, 248, 270 and 347 nm, respectively, were chosen as the monitoring wavelengths to determine four structural types of components, say columbin, phytoecdysteroids (including 20-hydroxyecdysone, 2-deoxy-20-hydroxyecdysone 3-O-beta-d-glucopyranoside and 2-deoxy-20-hydroxyecdysone), menisperine and protoberberine alkaloids (including columbamine, jatrorrhizine and palmatine). This method was validated in respect to precision, repeatability and accuracy, and was successfully applied to quantify the eight components in 39 batches of R. Tinosporae for quality control purpose. The results indicated that the proposed method could be readily utilized as a quality control method for traditional Chinese medicine (TCM).