Effect of type 2 diabetes mellitus on flavonoid pharmacokinetics and tissue distribution after oral administration of Radix Scutellaria extract in rats / 中国天然药物

Radix Scutellaria is widely applied to the treatment of diabetes mellitus in China. Its main bioactive constituents contain baicalin, wogonoside, oroxyloside, and their aglycones. To investigate the effect of type 2 diabetes mellitus on both pharmacokinetics and tissue distribution of these flavonoid compounds, the six flavonoids in plasma and tissues from the normal and type 2 diabetic rats after oral administration of Radix Scutellaria extract were simultaneously measured by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. The results showed that baicalin, wogonoside, and oroxyloside had higher C and AUC values (P < 0.05) in type 2 diabetic rats than that in normal rats and the tissue-distribution behaviors of the six flavonoid compounds in hearts, livers, spleens, lungs, kidneys, brains, pancreas, fat and muscle of the type 2 diabetic rats showed obviously differences from the normal rats (P < 0.05). In conclusion, the differences in the pharmacokinetics of oroxyloside and tissue distribution of the six flavanoids in Radix Scutellaria extract between diabetic and normal rats were found for the first time. The results from the present study provided a crucial basis for a better understanding of in vivo anti-diabetic mechanism of action of the six flavonoids from Radix Scutellaria.

Effect of type 2 diabetes mellitus on flavonoid pharmacokinetics and tissue distribution after oral administration of Radix Scutellaria extract in rats / 中国天然药物

Radix Scutellaria is widely applied to the treatment of diabetes mellitus in China. Its main bioactive constituents contain baicalin, wogonoside, oroxyloside, and their aglycones. To investigate the effect of type 2 diabetes mellitus on both pharmacokinetics and tissue distribution of these flavonoid compounds, the six flavonoids in plasma and tissues from the normal and type 2 diabetic rats after oral administration of Radix Scutellaria extract were simultaneously measured by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. The results showed that baicalin, wogonoside, and oroxyloside had higher C and AUC values (P < 0.05) in type 2 diabetic rats than that in normal rats and the tissue-distribution behaviors of the six flavonoid compounds in hearts, livers, spleens, lungs, kidneys, brains, pancreas, fat and muscle of the type 2 diabetic rats showed obviously differences from the normal rats (P < 0.05). In conclusion, the differences in the pharmacokinetics of oroxyloside and tissue distribution of the six flavanoids in Radix Scutellaria extract between diabetic and normal rats were found for the first time. The results from the present study provided a crucial basis for a better understanding of in vivo anti-diabetic mechanism of action of the six flavonoids from Radix Scutellaria.

Simultaneous Determination of Six Neurotransmitters in Rat Plasma, Adrenal Gland and Hypothalamus with Liquid Chromatography-Tandem Mass Spectrometry / 分析化学

A rapid Liquid chromatography-tandem mass spectrometry method was developed for the simultaneous determination of six neurotransmitters in rat plasma,adrenal gland and hypothalamus,including γ-aminobutyric acid (GABA),serotonin(5-HT), tyrosine(L-Tyr), dopamine(DA), norepinephrine(NE) and epinephrine(E). This method was used for the neurotransmitters detection in rat adrenal, blood and hypothalamus. The samples were pre-column derivatized with dansyl chloride,and 5-HTP and CA were used as internal standards. A Thermo C18column (50 mm×3 mm,2.7 μm) was used for sample separation with 0.1% aqueous formic acid solution as phase A and methanol as phase B at a flow rate of 0.2 mL/min, and the injection volume was set at 2 μL. The detection was carried out with multi-reaction monitoring(MRM) in electron spray ionization (ESI) positive mode. The linear ranges for detection of GABA,5-HT, L-Tyr, DA, NE and E were 0.26-620.80 μmol/L,0.03-11.20 μmol/L,1.20-88.00 μmol/L,0.03-41.02 μmol/L, 0.01-47.20 μmol/L, 0. 01-90. 24 μmol/L, respectively, with recoveries varying from 91. 16% to 116.20%. This method can detect the neurotransmitters rapidly and accurately, providing a platform for the determination of neurotransmitters in rat plasma, adrenal gland and hypothalamus in pharmacological experiments.

Application of modern mass spectrometry in metabolism and pharmacokinetics of traditional Chinese medicine / 药学学报

Modern mass spectrometry plays an important role in the study of metabolism and pharmacokinetics of traditional Chinese medicine due to its high sensitivity, high analysis speed and good stability. First, this article gives a brief introduction to the development of modern mass spectrometry techniques. Second, the application of modern mass spectrometry is summarized in the study of metabolism and pharmacokinetics of traditional Chinese medicine including in vitro and in vivo studies. In vitro research is reviewed with a focus on metabolism of intestinal bacteria and cytochrome P450 enzymes; in vivo research is covered mainly with a fo cuse on the application of microdialysis-MS, GC/LC-MS, new ambient mass spectrometry, and imaging mass spectrometry in metabolism and pharmacokinetics.

The metabolic fingerprint of the compatibility of Radix Aconite and Radix Paeoniae Alba and its effect on CYP450 enzymes / 药学学报

Using a UPLC-MS/MS (MRM) and cocktail probe substrates method, the metabolic fingerprint of the compatibility of Radix Aconite (RA) and Radix Paeoniae Alba (RPA) and its effect on CYP450 enzymes were investigated. These main CYP isoforms include CYP 1A2, CYP 2C, CYP 2E1, CYP 2D and CYP 3A. Compared with the inhibition effect of RA decoctions on CYP450 isoforms, their co-decoctions of RA and RPA with different proportions can decrease RA' inhibition on CYP3A, CYP2D, CYP2C and CYP1A2, but can not reduce RA' effect on CYP2E1. The metabolic fingerprints of RA decoction and co-decoctions with different proportions of RPA in CYP450 of rat liver were analyzed by UPLC-MS. Compared with the metabolic fingerprints of RA decoction, the intensity of diester-diterpenoid aconitum alkaloids decreased significantly, while the intensity of monoester-diterpenoid alkaloids significantly increased in the metabolic fingerprints of co-decoctions of RA and RPA. The results suggest that RA coadministration with RPA increased the degradation of toxic alkaloid and show the effect of toxicity reducing and efficacy enhancing.

High performance preparation and structural confirmation of lignans from Schisandrae chinensis fructus by using HSCCC combined with ESI-MSn method / 药学学报

High-speed counter-current chromatography (HSCCC) was used to high performance separate and prepare lignans from Schisandrae chinensis fructus. The solvent system is composed of n-hexane-ethyl acetate-methanol-water (9 : 1 : 5 : 5) and n-hexane-ethyl acetate-methanol-water (9 : 1 : 9 : 5), speed is at 900 r.min-1, and flow rate is at 2.0 mL.min-1. Five fractions from Schisandrae chinensis fructus extract were separated and prepared with one HSCCC process. They were identified as schisandrin, gomisin J, schisandrol B, schisantherin A and deoxyschizandrin by electrospray ionization-multiple tandem mass spectrometry (ESI-MSn), respectively. Their contents were obtained in 98.74%, 94.32%, 99.53%, 94.23% and 98.68% by ultra high performance liquid chromatography (UPLC), separately. The rapid and simple method can be applied for the preparation of lignans from Schisandrae chinensis fructus.

Effects of six kinds of Chinese herb extracts on the activities of rat liver microsomes in vitro / 药学学报

Effects of six kinds of Chinese herb extracts, including Folium Crataegi extract, Herba Epimedii extract, Folium Acanthopanacis Senticosi extract, Trifolium pratense L. extract, Folium Ginkgo extract and Radix Puerariae extract, on the activities of CYP450 isozymes (CYP1A2, CYP2C, CYP2E1, CYP2D, CYP3A) in rat hepatic microsomals were studied by using a UPLC-MS/MS (MRM) and cocktail probe substrates method. The results showed that effects of six kinds of Chinese herb extracts on each CYP450 isozyme activity were inhibitory. The IC50 of Folium Crataegi extract for the inhibition of rat microsomal CYP2D activity was only for 4.04 microg x mL(-1), which showed the highest inhibition; Trifolium pratense L. extract had strong inhibitory action to CYP2D, the IC50 value was 5.73 microg x mL(-1); Folium Crataegi extract also had strong inhibitory action on CYP2E1, the IC50 value was 10.91 microg x mL(-1). Furthermore, the IC50 of Folium Ginkgo extract for the inhibition of rat microsomal CYP3A, 2D, 2E1 activities were 45.12, 35.45 and 22.41 microg x mL(-1), respectively, and the IC50 of Folium Acanthopanacis Senticosi extract on the inhibition of rat microsomal CYP2E1 activity was 32.89 microg x mL(-1). In addition, mechanism of inhibition experimental results showed that the inhibiting abilities of Folium Crataegi extract and Radix Puerariae extract on each CYP450 isozyme increased with the increasing of the preincubation time, therefore, the inhibitory effects were a mechanism-based inhibition.

Metabolites and metabolic pathways of mesaconitine in rat liver microsomal investigated by using UPLC-MS/MS method in vitro / 药学学报

Mesaconitine was incubated with rat liver microsomes in vitro. The metabolites of mesaconitine in rat liver microsomes were identified by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method with high resolution power. A typical reaction mixture of 100 mol L-1 Tris-HCI buffer (pH 7.4) containing 0.5 gL-1 microsomal protein and 50 micro molL-1 mesaconitine was prepared. The above reaction mixture was divided into six groups, and the volume of each group was 200 micro L. The incubation mixture was pre-incubated at 37 degrees C for 2 min and the reactions were initiated by adding NADPH generating system. After 90 min incubation at 37 degrees C, 200 micro L of acetonitrile was added to each group to stop the reaction. The metabolites of mesaconitine were investigated by UPLC-MS/MS method. Mesaconitine and 6 metabolites M1-M6 were found in the incubation system. The structures were characterized according to the data from MS/MS spectra and literatures. The metabolic reactions of mesaconitine in rat liver microsomes included the demethylation, deacetylation, dehydrogenation and hydroxylation. The major metabolic pathways of mesaconitine in rat liver microsomes were determined by UPLC-MS/MS on multiple reaction monitoring (MRM) mode combined with specific inhibitors of cytochrome P450 (CYP) isoforms, including alpha-naphthoflavone (CYP1A2), quinine (CYP2D), diethyldithiocarbamate (CYP2E1), ketoconazole (CYP3A) and sulfaphenazole (CYP2C), separately. Mesaconitine was mainly metabolized by CYP3A. CYP2C and CYP2D were also more important CYP isoforms for the metabolism reactions of mesaconitine, but CYP1A2 and CYP2E1 haven't any contribution to MA metabolism in rat liver microsomes.

Change of the content of chemical constituents and anti-oxidative action of the decoction of radix ginseng combined with Flos Lonicerae, radix Polygoni Multiflori and Radix Astragali / 药学学报

Ginsenosides in the decoction of Radix Ginseng, Radix Ginseng with Flos Lonicerae, Radix Polygoni Multiflori or Radix Astragali have been investigated by high performance liquid chromatography (HPLC) and electrospray ionization mass spectrometric method (ESI-MS). Change of the content of ginsenosides was nonlinear in diverse combinative proportion of Radix Ginseng with Flos Lonicerae, while the stripping of ginsenosides was promoted by a small amount of Radix Polygoni Multiflori. In the combinative decoction of Radix Ginseng with Radix Astragali, ginsenosides contents were increased compared to single decoction of Radix Ginseng. Besides, ferric reducing antioxidant power (FRAP) method was developed for determination of the total antioxidative activity of n-butanol and water-soluble extracts from the decoction. The experimental results showed that antioxidative activity was better in the combinative decoction than that in single decoction, and the FRAP values of n-butanol extract were also greater compared with that of water extract.

Studies on change of chemical composition in coptis-scute herb couple by using HPCE and HPLC / 药学学报

Quantitative analysis on different proportions of couple of Coptis and Scute. The proportions of Coptis and Scute couple were 6:1, 6:4, 6:7, 6:10, 6:13, separately. The contents of alkaloids in Coptis and decoction of Coptis and Scute were determined by HPCE and the contents of flavones in Scute and decoction of Coptis and Scute were determined by HPLC, separately. Precipitates were generated after the couple of Coptis and Scute, which results the decrease of contents of effective ingredients.

Lignans from different processed products of Schisandra chinensis fruits / 药学学报

To study the lignan components of different processed products of Schisandra chinensis fruits, the study was conducted with electrospray ionization mass spectrometry (ESI-MS) and high performance liquid chromatography (HPLC). There was no new lignan components detected from the products obtained with different processed methods, the difference was in the content of lignan components. The method is accurate and effective, which can be used to evaluate the quality of different processed products of Schisandra chinensis fruits.

Interaction between anticancer drugs and DNA studied by using electrospray ionization mass spectrometry / 药学学报

To elucidate further sequence selectivity and nature of the binding of anticancer drugs to DNA, the interaction between anticancer drugs, which are minor groove ligands (distamycin A, DM and netropsin, NP) and intercalator (mitoxantrone, MT), and DNA were studied by electrospray ionization mass spectrometry. The 2 : 1 specific complex of DM and AT-rich DNA were observed principally, while only 1 : 1 specific complex of NP and AT-rich DNA were observed. MT specifically binds to GC-rich DNA. In addition, DM binds to DNA containing 5 A/T bases minor groove almost in a 2 : 1 mode and does not bind to DNA containing 3 A/T bases minor groove. NP binds most strongly to DNA containing 4 A/T bases minor groove. The 1 : 1 specific complex of MT and 6-mer DNA was also observed. The result of competitive binding experiment shows that DM binds more strongly to AT-rich DNA than NP does. These results provide bases for investigating the mechanism of interaction between the drugs and DNA and for improving the structure of target drug.

Analysis of aconite alkaloids in the combination of radix aconiti lateralis preparata with different herbs by ESI-MS spectrometry / 药学学报

The method was established study the influence of different herbal combination with Radix Aconiti in the traditional medical formulae on content of the aconite alkaloids, for elucidating the scientific basis of reducing the toxicity of aconite in traditional Chinese medical formulation. The samples for ESI-MS study were prepared by decocting a mixture of Radix Aconiti Lateralis Preparata ( RALP) with Radix Glycyrrhizae Preparata (RGP) , Radix Paeoniae Alba ( RPA) , Rhizoma Zingiberis (RZ) or Radix Et Rhizoma Rhei ( RERR) , separately, and extracting the residue of the above mentioned mixtures after decocting. The diester-diterpenoid alkaloids (DDAs) was lower in the herb couples of RALP-RGP, RALP-RPA, RALP-RZ and RALP-RERR, and lipo-alkaloids was increased in the herb couples of RALP-RGP, RALP-RPA and RALP-RZ. The reason of reducing toxic effect principle is that the components of RGP, RPA and RZ have ester-exchange reactions with DDAs in RALP to produce lipo-alkaloids of low toxicity in the decocting process of the herb couples. The combination of RALP-RERR can reduce the content of DDAs in decoction and residue due to the formation of water insoluble alkaloid compound.

Study on Aconitum diterpenoid alkaloids from flowers of Aconitum kusnezoffi and its decoction by ESI-MS / 药学学报

<p><b>AIM</b>To study the change of chemical compound after decocting the flowers of Aconitum kusnzoffii Reichb (FAK) by analyzing the alkaloids in FAK and the decoction of FAK qualitatively.</p><p><b>METHODS</b>The alkaloid extracts of FAK and alkaloid mixtures in the decoction of FAK were directly analyzed by electrospray ionization trap tandem mass spectrometry via by pump.</p><p><b>RESULTS</b>Three novel aconitum alkaloids were found in FAK. In addition, it is found that both diester diterpenoid alkaloids and triester diterpenoid alkaloids were hydrolyzed in the decoction of FAK. The hydrolysis products of the diester-alkaloids are benzoylaconines and aconines; the hydrolysis products of the triester-alkaloids are 3-acetyl-aconines.</p><p><b>CONCLUSION</b>ESI-MS" method is suitable for the analysis of Aconitum alkaloids in the decoction of FAK as well as other Aconitum plants, which offers the advantages of convenience, speed, sensitivity and specificity.</p>

Study on the combination principles about aconite roots by electrospray ionization mass spectrometry / 药学学报

<p><b>AIM</b>To explore the combination principle about aconite roots from the chemical point of view.</p><p><b>METHODS</b>Analyzing and comparing the nordeterpenoid alkaloids in the crude aconite roots, the decoction of crude aconite roots and aconite roots with some other Chinese traditional herbs by electrospray ionization trap tandem mass spectrometry. Detecting the pH value of the decoction of crude aconite roots and of some other Chinese traditional herbs; studying the influence of acidity to the hydrolysis of standard sample of mesaconitine.</p><p><b>RESULTS</b>Most of diester-diterpenoid alkaloids in the decoction of aconite roots and the decoction of aconite roots with liquorice roots are hydrolyzed, and the hydrolysis of alkaloids are inhibited in the decoction of aconite roots with Pinellia tuber or Schisandra. The acidity of the decoction of aconite roots or liquorice is lower than the decoction of Pinellia tuber or Schisandra; standard sample of mesaconitine can not be hydrolyzed in acid water.</p><p><b>CONCLUSION</b>Acidity is a key factor to influence the hydrolysis of diester-diterpenoid alkaloids, and the hydrolysis of alkaloids are inhibited in high acidity, which lead to the high toxicity of the decoction containing aconite roots.</p>