Astragali Radix Extract Research Articles

Effect of Astragali radix extract on pharmacokinetic behavior of dapagliflozin in healthy and type 2 diabetic rats.

Objective: This study aimed to investigate effect of antidiabetic herb Astragali Radix (AR) on pharmacokinetic behavior of dapagliflozin (DAPA) in healthy rats and type 2 diabetes mellitus (T2DM) rats. Methods: The T2DM rats were induced by high-fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ). Concentrations of DAPA in healthy and T2DM rat plasma were determined by UPLC-MS/MS method. Effect of AR extract (ARE) on pharmacokinetic behavior of DAPA in healthy and T2DM rats was evaluated, respectively. Results: The diabetes status and co-administrated with ARE significantly affected pharmacokinetic behaviors of DAPA in the rats. Compared to that in healthy rats, t max of DAPA significantly shortened, its C max significantly increased in T2DM rats, and its t 1/2, V, AUC, CL and MRT kept unchanged. When ARE was co-administrated with DAPA, C max of DAPA significantly increased, its t max and MRT significantly decreased, and its t 1/2, V, AUC and CL kept unchanged in healthy rats. t max and C max of DAPA significantly decreased, its t 1/2 and V significantly increased, and its AUC, CL and MRT were unchanged in T2DM rats when ARE was co-administrated with DAPA. Co-administration of DAPA and ARE promoted absorptive rate of DAPA, increased its extravascular tissue distribution, and prolonged its duration of action. ARE did not cause accumulation of DAPA in vivo. Conclusion: Both disease status of T2DM and co-administration of ARE affect pharmacokinetic behavior of DAPA in vivo. Potential pharmacokinetic interactions may occur in vivo when herbs and drugs are co-administrated, which may affect efficacy and safety of drugs.

Anti-Mutagenic and Immunomodulatory Effects of Astragali Radix Extract on a Cyclophosphamide-Induced Immunosuppressed Mouse Model

Although the immunomodulatory effects of Astragali Radix extract (AR) have been documented, its anti-mutagenic activity, a problem arising from chemotherapeutic agents, is rarely reported. Therefore, the anti-mutagenic and immunomodulatory effects of AR were investigated using a cyclophosphamide (CPA)-induced immunosuppressed mouse model to develop an alternative immunomodulatory agent. The fluid-bed-dried aqueous extract of AR containing 37.5% dextrin and exopolymers purified from Aureobasidium pullulans SM-2001 (EAP) were used in this study. The therapeutic potentials of AR at doses ranging from 100 mg/kg to 400 mg/kg was estimated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) based cytotoxicity and splenocyte proliferation assay, body weight and lymphatic organ weight measurements, hematological measurements, serum and spleen cytokine level measurements, natural killer (NK) cell activity measurements, real-time RT-PCR expressions of splenic mRNA, a micronucleus test, histopathological observations, and immunohistochemical measurements. In CPA-treated mice, a clear immunosuppressive effect was observed for all tested parameters. However, the oral administration of AR (100, 200, and 400 mg/kg) showed dose-dependent and favorable inhibitory activities on CPA-induced immunosuppression and mutagenicity as compared to 200 mg/kg EAP. Furthermore, AR (100–400 mg/kg) up-regulated the nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB) which are related to NK-, T-, and B-cell activation, with no critical cytotoxicity. The results of this study clearly demonstrate that AR at an appropriate oral dose could act as a potential alternative agent with significant anti-mutagenicity and immunomodulatory properties.

A calibration method based on model updating strategy for the quantitative model of Radix Astragali extract

The main purpose of this study was to construct a calibration model based on model updating strategy for the quantitative analysis of three active components in Radix Astragali extract (RAE). To verify the feasibility of quantitative model by a small portable near-infrared (NIR) spectrometer, a comparison with Fourier Transform near-infrared (FT-NIR) spectrometer was also carried out. Partial least square regression (PLSR) models were established for quantitation of three ingredients including astragaloside IV (AST IV), calycosin-7-glucoside (CG) and astragaloside polysaccharide (APS) for quality control and evaluation of RAE. For new samples, a model-based update strategy was proposed to correct the quantitative models for reducing the influence of the manufacturer and extraction method on the NIR model. A novel Cluster Center Distance (CCD) method was also proposed to select the representative candidate samples added to the calibration set for updating the calibration model which was more suitable for new samples, and three sample-selection methods such as Random sampling (RS), Kennard-Stone (KS) and joint x-y distances (SPXY) were used for comparison. The results indicated that the established calibration method based on a model updating strategy might improve the model's adaptability to new samples significantly. The proposed CCD method had certain advantages in model update and could improve the model's accuracy in predicting the new samples.

Comparative stomach tissue distribution profiles of four major bio-active components of Radix Astragali in normal and gastric ulcer mice

Numerous studies have demonstrated that Radix Astragali can inhibit gastric ulcers in mice. Anhydrous ethanol (0.01 mL/g) administered to mice by intragastric infusion can induce gastric ulcer injury. This study was performed to compare the stomach tissue distribution profiles of four major bioactive constituents of Radix Astragali(calycosin-7-O-β-d-glucoside, calycosin, ononin and formononetin) after oral administration of extract of Radix Astragali (ERA)in normal and gastric ulcer mice. The abundance of Radix Astragali constituents was determined using an ultra-pressure liquid chromatograph with a photodiode array detector (UPLC-PDA), after which histograms were drawn. In comparison with normal mice, the contents of calycosin- 7-O-β-d-glucoside, calycosin, ononin and formononetin in the stomach tissue samples of gastric ulcer mice showed significant differences at the selected time points (P < 0.05).The abundance of each of the four tested constituents in the normal groups was higher than that of the gastric ulcer groups. This study provides an empirical foundation for future studies focused on developing clinical applications of Radix Astragali.

Octadecylimidazolium ionic liquids-functionalized carbon dots and their precursor co-immobilized silica as hydrophobic chromatographic stationary phase with enhanced shape selectivity

In this work, 1-vinyl-3-octadecylimidazolium bromide ionic liquids ([C18VIm]Br) and their derived carbon dots (ImC18CDs) were prepared, [C18VIm]Br and ImC18CDs were grafted on the silica to obtain Sil-ImC18 and Sil-ImC18CDs, respectively, and they were also co-grafted on silica which named Sil-ImC18/CDs. Compared with Sil-ImC18 and Sil-ImC18CDs columns, Sil-ImC18/CDs column exhibited enhanced selectivity for separation of tetracyclic/tricyclic polycyclic aromatic hydrocarbon (PAH) isomers, and butylbenzene isomers in reversed-phase liquid chromatography, which may be due to the synergistic effect between ImC18CDs and [C18VIm]Br, the π-π interaction between imidazolium and analytes, etc. Meanwhile, the retention behavior of Sil-ImC18/CDs was further evaluated and compared with the commercial C18 column using different classes of analytes, including standard test mixtures of Tanaka, Engelhardt, SRM869b, SRM870. The results demonstrated that co-grafted column exhibited superior separation performance. And this column was applied to determine the contents of calycosin-7-glucoside, ononin, calycosin and formononetin in the extract of Radix Astragali, which were found that the concentration was 0.25 mg mL−1, 0.15 mg mL−1, 0.13 mg mL−1 and 0.30 mg mL−1, respectively.

Octadecylamine and glucose-coderived hydrophobic carbon dots-modified porous silica for chromatographic separation

A hydrophobic carbon dots (Glc-OCDs) derived from octadecylamine and glucose were successfully synthesized for the first time and then grafted onto the porous silica surface by the “Nano-on-Micro” strategy, which was served as a new stationary phase (Sil-Glc-OCDs) for reversed-phase liquid chromatography. The structure of this stationary phase was carefully verified by laser scanning confocal microscope, Fourier transform infrared spectrometry, elemental analysis, contact angle measurement, etc. Several analytes including seven polycyclic aromatic hydrocarbons, eight alkylbenzenes, eight phenols and seven sulfonamides can be well separated on this stationary phase. Better separation performance for certain analytes over commercial C18 column was obtained. Interestingly, this stationary phase exhibited excellent chromatographic selectivity in the separation of the isomers of tert‑butylbenzene, sec‑butylbenzene, isobutylbenzene and n-butylbenzene. In addition, this new Sil-Glc-OCDs column was also applied for detection of calycosin-7-glucoside, ononin, calycosin, formononetin, genistein and isorhamnetin in the extract of Radix Astragali, which were found that the concentration was 0.15 g/L, 0.088 g/L, 0.14 g/L, 0.086 g/L, 0.18 g/L and 0.29 g/L, respectively. We believe that this CDs-grafted silica materials are promising for chromatographic separation.

Hypoglycemic effect of Taraxacum officinale root extract and its synergism with Radix Astragali extract.

Taraxacum officinale (dandelion) and Radix Astragali are traditional medicinal and edible plants with high nutritional value. In this study, the synergistic hypoglycemic effect of DRE and Radix Astragali extract (RAE) was evaluated. Our results showed that water extract of dandelion (DRE‐w), mainly containing polysaccharides (63.92 ± 1.82 mg/g), total flavonoid (2.57 ± 0.06 mg/g), total phenolic compounds (8.93 ± 0.34 mg/g), and saponins (0.54 ± 0.05 mg/g), exhibited significantly inhibitory effect on α‐glucosidase and α‐amylase. DRE‐w and RAE had synergistic hypoglycemic effect; we found that DRE‐w and its combination with RAE could relieve the state of insulin resistance in IR‐HepG2 cells. The combination could more significantly increase the glucose consumption and intracellular glycogen content, and improve the activity of hexokinase and pyruvate kinase in IR‐HepG2 cells. In summary, DRE and its combination with RAE can be developed as the drugs or functional foods for diabetes prevention and treatment.

Quality assessment of Astragali Radix from different production areas by simultaneous determination of thirteen major compounds using tandem UV/charged aerosol detector

To identify more chemical markers for improving the quality standard and evaluate producing areas differentiation of Astragali Radix (AR), a simple, low-cost and reliable chromatography method based on a high performance liquid chromatography (HPLC) coupled with ultraviolet (UV) detector and charged aerosol detector (CAD) for separation of 13 major chemical components, including 8 flavonoids and 5 astragalosides in AR extract, was developed. The contents of 13 compounds in total of 27 herb samples, collected from different cultivating regions, were determined and compared. Moreover, chemometric analysis techniques with principal component constituent analysis (PCA) and cluster analysis (CA) were performed to discriminate the samples from different producing areas. As a result, an obvious linkage between the content of components and collecting areas was found. Results showed that the content of astragaloside III and astragaloside IV could be used to differentiate samples collected from Northeast China, Inner Mongolia and Shanxi Province, suggesting that they should be added as the chemical marker for further investigation on the pharmacological actions and the quality control of AR.

A efficient method to identify cardioprotective components of Astragali Radix using a combination of molecularly imprinted polymers-based knockout extract and activity evaluation

Although herb medicines have become the major source for new drug discovery, many of them are largely under-explored due to the purity-activity relationship. Efficient identification of bioactive compounds in conventional stepwise separation and isolation has not yet been elucidated. Therefore, we proposed a new separation strategy for holism understanding of herb pharmacology using molecularly imprinted polymers (MIPs). Astragali Radix (AR), important in traditional Chinese medicine, was chosen in this study for multicomponent knockout followed by bioactivity evaluation. We prepared calycosin molecularly imprinted polymers (calycosin-MIPs) which could selectively recognize flavonoid aglycons in AR. The molecular selectivity of calycosin-MIPs as a critical parameter was evaluated using the template and other high content compounds in AR. Based on it, using the calycosin-MIPs material via solid-phase extraction procedures was applied for the knockout of flavonoid aglycons in AR. Finally, hypoxia/reoxygenation model in H9c2 cells was used to evaluate the activity of the AR extract before and after knockout. The results showed that calycosin-MIPs as recognition materials for flavonoid aglycons in AR are applied in one-step separation with high selectivity and tunability. The subextract in the absence of flavonoid aglycons has been demonstrated to clarify the cardio-protective components of AR. In conclusion, this proof-of-principle study is the first one showing that molecular imprinting technology coupled with a bioassay can be used to explore the bioactive variability from the perspective of multicomponent separation of herbal medicine.

A novel quality by design approach for developing an HPLC method to analyze herbal extracts: A case study of sugar content analysis.

The aim of this study was to present a novel analytical quality by design (AQbD) approach for developing an HPLC method to analyze herbal extracts. In this approach, critical method attributes (CMAs) and critical method parameters (CMPs) of the analytical method were determined using the same data collected from screening experiments. The HPLC-ELSD method for separation and quantification of sugars in Codonopsis Radix extract (CRE) samples and Astragali Radix extract (ARE) samples was developed as an example method with a novel AQbD approach. Potential CMAs and potential CMPs were found with Analytical Target Profile. After the screening experiments, the retention time of the D-glucose peak of CRE samples, the signal-to-noise ratio of the D-glucose peak of CRE samples, and retention time of the sucrose peak in ARE samples were considered CMAs. The initial and final composition of the mobile phase, flow rate, and column temperature were found to be CMPs using a standard partial regression coefficient method. The probability-based design space was calculated using a Monte-Carlo simulation method and verified by experiments. The optimized method was validated to be accurate and precise, and then it was applied in the analysis of CRE and ARE samples. The present AQbD approach is efficient and suitable for analysis objects with complex compositions.

Sulfotransferases and Breast Cancer Resistance Protein Determine the Disposition of Calycosin in Vitro and in Vivo

Sulfation is a key process of drug disposition that generally regulates drug effectiveness and toxicity. Calycosin derived from the dry root extract of Radix Astragali exhibits a variety of biological effects that easily undergo extensive phase II metabolism. However, the sulfation pathway of calycosin lacks information. We investigated the disposition mechanisms of calycosin sulfate in vitro and in vivo. We characterized the sulfation metabolism and excretion of calycosin using bidirectional transport studies. We confirmed that sulfate conjugate is breast cancer resistance protein (BCRP) substrate using the intestinal perfusion model and pharmacokinetics studies in Bcrp1-/- mice. Results showed that calycosin is rapidly and extensively metabolized to calycosin-3'-sulfate (C-3'-S) in the intestine and liver. The overexpression of BCRP led to a substantial increase (approximately 14-fold, p < 0.01) of excreted C-3'-S in the BCRP overexpressed Madin-Darby canine kidney II (MDCK II/BCRP) cells. The chemical inhibition of BCRP caused reduction (about 2-fold, p < 0.01) in C-3'-S apical excretion. Furthermore, in intestinal perfusion studies, the deletion of Bcrp1 significantly decreased C-3'-S excretion in the small intestine (82.6-90.6%, p < 0.01) and colon (97.6-98.2%, p < 0.01). In contrast, plasma level of C-3'-S was increased to 40-fold (p < 0.01) in Bcrp1-/- mice. In conclusion, calycosin undergoes an extensive sulfation metabolism and BCRP is a critical determinant to the disposition of C-3'-S.

Rapid and reliable method for analysis of raw and honey-processed astragalus by UPLC/ESI-Q-TOF-MS using HSS T3 columns

A novel method has been developed for rapid analysis of the major constituents in Radix Astragali and honey-processed Astragalus within 23 minutes using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-Q-TOF-MS). Separation analysis was performed on HSS T3 columns with a gradient elution of acetonitrile-water containing 0.1% formic acid at a flow rate of 0.3 mL min−1. Methodology validation showed that the established method had good repeatability (RSD < 8.07%), intra-day precisions (RSD < 4.20%), and stability (RSD < 7.78%). Accurate molecular weight and characteristic fragment ions obtained from Q-TOF-MS provided a reliable criterion for the structural characterization of the major compounds in raw and honey-processed Astragalus. 35 major constituents, including flavonoids, isoflavan, pterocarpan, and saponins, were identified or tentatively characterized by comparing their retention times and MS spectra with those of authentic standards and literature data. Furthermore, quantitative analysis revealed that the content changes of chemical compositions could cause the tonic effect differences between raw and honey-processed Astragalus. The established method is rapid and reliable for simultaneous analysis of constituents in an extract of Radix Astragali. Moreover, this method will simplify further studies of metabolism and pharmacodynamics and will encourage the use of HSS T3 columns in similar traditional Chinese medicine research.

Quality Control of Danggui Buxue Tang, a Traditional Chinese Medicine Decoction, by (1)H-NMR Metabolic Profiling.

Danggui Buxue Tang (DBT) is one of the simplest traditional Chinese medicine (TCM) decoctions, first described in China in 1247 AD. DBT is composed of 2 herbs, Astragali Radix (AR) and Angelica Sinensis Radix (ASR), boiled together in a 5 : 1 ratio. Clinically, DBT is prescribed to women as a remedy for menopausal symptoms. Here, H-NMR metabolic profiling was conducted for DBT and the water extracts of AR or ASR, to evaluate the potential of this chemical profiling method for quality control of the herbal decoction. Principal component analysis (PCA) showed that DBT could be readily distinguished from the water extracts of its constituent herbs by the metabolic profiles. More interestingly, the metabolic profile of DBT was not a simple sum of that of AR and ASR. Asparagine was found at significantly higher concentration in DBT than that in either AR or ASR extract, contributing mainly to the discrimination of DBT sample. In addition, we employed the same method to profile a commercial DBT powder, verifying its authenticity as compared to our prepared DBT. This study is the first to employ H-NMR metabolic profiling for the quality control of traditional Chinese medicine decoctions.

Can Hedysari Radix replace Astragali Radix in Danggui Buxue Tang, a Chinese herbal decoction for woman aliment?

Astragali Radix (AR) has been used for over 2000 years in China for the enrichment of “Qi”. Hedysari Radix (HR), a herb having similar chemical composition with AR, has been commonly used as a substitute of AR in herbal decoction. In order to evaluate the possible replacement of HR for AR in Chinese herbal decoction, systematic comparison of AR and HR was done by chemical and biological assessments. The water extract of AR contained higher levels of calycosin, calycosin-glucoside, ononin, astragaloside III and astragaloside IV, while higher amount of formononetin was found in the HR extract. The estrogenic, erythropoetic and osteogenic effects were compared between the water extracts of AR and HR, and in all cases AR extract showed higher biological activities. Danggui Buxue Tang (DBT) is a very common herbal decoction for woman aliment, and which contains AR and Angelica Sinensis Radix. Here, we generated two forms of DBT having either AR or HR as the major herbs. Chemically, AR-contained DBT showed higher amounts of various active chemicals, except formononetin that was higher in HR-contained DBT. In parallel, the estrogenic, osteogenic and erythropoetic effects of DBT containing AR showed better activities than that of DBT having HR. Thus, AR and HR showed distinct differences in terms of chemical and biological properties. In order to achieve the best therapeutical effect, as well as to guarantee the safety, AR is recommended here to be used for making DBT.

Anti-atherosclerotic function of Astragali Radix extract: downregulation of adhesion molecules in vitro and in vivo

BackgroundAtherosclerosis is considered to be a chronic inflammatory disease. Astragali Radix extract (ARE) is one of the major active ingredients extracted from the root of Astragalus membranaceus Bge. Although ARE has an anti-inflammatory function, its anti-atherosclerotic effects and mechanisms have not yet been elucidated.MethodsMurine endothelial SVEC4-10 cells were pretreated with different doses of ARE at different times prior to induction with tumor necrosis factor (TNF)-α. Cell adhesion assays were performed using THP-1 cells and assessed by enzyme-linked immunosorbent assay, western blotting and immunofluorescence analyses to detect the expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), phosphorylated inhibitor of κB (p-iκB) and nuclear factor (NF)-κB. We also examined the effect of ARE on atherosclerosis in the aortic endothelium of apolipoprotein E-deficient (apoE−/−) mice.ResultsTNF-α strongly increased the expression of VCAM-1 and ICAM-1 accompanied by increased expression of p-iκB and NF-κB proteins. However, the expression levels of VCAM-1 and ICAM-1 were reduced by ARE in dose- and time-dependent manners, with the strongest effect at a dose of 120 μg/ml incubated for 4 h. This was accompanied by significantly decreased expression of p-iκB and inhibited activation of NF-κB. Immunofluorescence analysis also revealed that oral administration of ARE resulted in downregulation of adhesion molecules and decreased expression of macrophages in the aortic endothelium of apoE−/− mice. ARE could suppress the inflammatory reaction and inhibit the progression of atherosclerotic lesions in apoE−/− mice.ConclusionThis study demonstrated that ARE might be an effective anti-inflammatory agent for the treatment of atherosclerosis, possibly acting via the decreased expression of adhesion molecules.

Extracts from Radix Astragali and Radix Rehmanniae Promote Keratinocyte Proliferation by Regulating Expression of Growth Factor Receptors

Chinese herbal medicine has long been used as a treatment for wounds. However, the underlying cellular and molecular mechanisms remain largely unknown. In this study it was shown that the proliferation of keratinocytes, which is known to play an important role in wound healing as the major cell type in the epidermis, was promoted by three herbal extracts/natural compounds: NF3 (an extract from the mixture of Radix Astragali (RA) and Radix Rehmanniae (RR) in the ratio of 2:1), stachyose (an isolated compound from Radix Rehmanniae) and extract P2-2 (a sub-fraction from the extract of Radix Astragali). The effect of the herbal extracts/natural compounds on the growth of keratinocytes was not influenced by a high glucose level, a condition similar to diabetic patients who usually suffer from diabetic foot ulcers. Real time RT-PCR results showed that the expression of epidermal growth factor (EGF) receptor, but not transforming growth factor-β (TGF-β) receptor, was up-regulated by NF3. Moreover, treatments with the EGF receptor kinase inhibitor AG1478 and the MEK inhibitor U0126 resulted in the diminishment of the effect of the three herbal extracts/natural compounds on keratinocyte proliferation, indicating that EGF receptor might have a significant role in this action. This study has further elucidated the molecular mechanism under which herbal extracts/natural compounds exert their effects on the wound healing process.

Neuroprotective effect of modified Boyanghwano-Tang and the major medicinal plants, Astragali Radix and Salviae Miltiorrhizae Radix on ischemic stroke in rats

Objectives : In this study, the neuroprotective effects of modified Boyanghwano-Tang (mBHT) and the major medicinal plants, Astragali Radix(AR) and Salviae Miltiorrhizae Radix(SMR) were investigated in transient middle cerebral artery occlusion (tMCAO)-induced ischemic stroke of rats. Methods : mBHT(400 mg/kg) and AR(154 mg/kg) or SMR(62 mg/kg) water extract orally injected in rats after 90 min occlusion of MCA and then allow reperfusion to 24 h. Brain infarction was measured by TTC staining and the expressions of NOS isoforms and apoptotic molecules were determined in ischemic brain by Western blot. Results : The results showed that mBHT has stronger neuropreotective property through inhibitions of the PARP cleaved and caspase-3 activation in ischemic rats, and could reduced infarction volumes comparison of those of AR or SMR, respectively. While, AR extract has an angiogenic property through increasing the expressions of eNOS and VEGF, and SMR extract has a strong anti-inflammatory effects through inhibition of iNOS expression in ischemic brains. Conclusions : These results suggest that mBHT has multifactorial therapeutic advantages through anti-apoptosis, anti-inflammation and angiogenesis for ischemic stroke based on a synergistic combination of ingradients rather than monotherapy.

Radix Astragali extract promotes angiogenesis involving vascular endothelial growth factor receptor‐related phosphatidylinositol 3‐kinase/Akt‐dependent pathway in human endothelial cells

Angiogenesis plays an important role in a wide range of physiological processes and many diseases are associated with dysregulation of angiogenesis. Radix Astragali, commonly used in traditional Chinese medicine, is a potential candidate for treating such diseases. However, the biological effects of Radix Astragali on angiogenesis and its underlying mechanisms are yet to be elucidated fully. This study describes the angiogenic effects of Radix Astragali extract (RAE) on human umbilical vein endothelial cells (HUVEC) in vitro. It was shown that RAE treatment stimulated HUVEC to proliferate. A significant increase in migration was observed in RAE-treated HUVEC using the wound healing migration assay. In addition, a significant increase in the number of branching points was observed during endothelial cell capillary formation after RAE treatment. It was shown that RAE enhances vascular endothelial growth factor (VEGF) mRNA expression, and that a specific blocker of VEGF receptor 2 (KDR/Flk) inhibited the RAE-induced HUVEC proliferation. In addition, a decrease in the RAE-induced HUVEC proliferation was observed after treatment with inhibitors of phosphatidylinositol 3-kinase (PI3K), Akt and endothelial nitric oxide synthase (eNOS). Taken together, these data suggest that RAE is a potent stimulator of angiogenesis and that its pro-angiogenic effects involve the VEGF-KDR/Flk and PI3K-Akt-eNOS pathways.

Studies on principal components and antioxidant activity of different Radix Astragali samples using high-performance liquid chromatography/electrospray ionization multiple-stage tandem mass spectrometry

The principal components, isoflavonoids and astragalosides, in the extract of Radix Astragali were detected by a high-performance liquid chromatography couple to electrospray ionization ion trap multiple-stage tandem mass spectrometry (HPLC-ESI-IT-MS n ) method. By comparing the retention time ( t R) of HPLC, the ESI-MS n data and the structures of analyzed compounds with the data of reference compounds and in the literature, 17 isoflavonoids and 12 astragalosides have been identified or tentatively deduced. By virtue of the extracted ion chromatogram (EIC) mode, simultaneous determination of isoflavonoids and astragalosides could be achieved when the different components formed overlapped peaks. And this method has been utilized to analyze the constituents in extracts of Radix Astragali from Helong City and of different growth years. Then the antioxidant activity of different samples has been successfully investigated by HPLC-ESI-MS method in multiple selected ion monitoring (MIM) mode, applying the spin trapping technology, and the Ferric Reducing Antioxidant Power (FRAP) assay was applied to support the result. The correlations of the isoflavonoids and astragalosides components and the antioxidant activities of Radix Astragali were summarized. The present paper demonstrates that HPLC-ESI-MS n is a powerful method for the characterization of the principal components and evaluation of the antioxidant activity of Chinese medicinal herbs.

Quantitative Evaluation of Radix Astragali through the Simultaneous Determination of Bioactive Isoflavonoids and Saponins by HPLC/UV and LC-ESI-MS/MS

The three major active isoflavonoids (calycosin-7-O-β -glucoside, isomucronulatol 7-O-β-glucoside, formononetin) and two main saponins (astragaloside I, astragaloside IV) in an extract of Radix Astragali were determined using rapid, sensitive, reliable HPLC/UV and LC-ESI-MS/MS methods. The separation conditions employed for HPLC/UV were optimized using a phenyl-hexyl column (4.6 × 150 mm, 5 μm) with the gradient elution of acetonitrile and water as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 230 nm. The specificity of the peaks was determined using a triple quadrupole tandem mass spectrometer equipped with an electrospray ionization (ESI) source that was operated in multiple reaction monitoring (MRM) in the positive mode. These methods were fully validated with respect to the linearity, accuracy, precision, recovery and robustness. The HPLC/UV method was applied successfully to the quantification of three major isoflavonoids in the extract of Radix Astragali. The results indicate that the established HPLC/UV and LC-ESI-MS/MS methods are suitable for the quantitative analysis and quality control of multi-components in Radix Astragali.