5-7-dihydroxy-6-methoxy-2-phenylchromen-4-one has been researched along with baicalein* in 33 studies
33 other study(ies) available for 5-7-dihydroxy-6-methoxy-2-phenylchromen-4-one and baicalein
Article | Year |
---|---|
Topics: Ethanol; Flavanones; Flavonoids; Plant Roots; Plants; Saccharomyces cerevisiae | 2022 |
Molecular Mechanism of the Effect of Huanglian Jiedu Decoction on Type 2 Diabetes Mellitus Based on Network Pharmacology and Molecular Docking.
Huanglian Jiedu Decoction (HLJDD) is a Traditional Chinese Medicine (TCM) formula comprising four herbal medicines. This decoction has long been used in China for clinically treating T2DM. However, the molecular mechanism of HLJDD treat for T2DM is still not fully known. Hence, this study was designed to reveal the synergistic mechanism of HLJDD formula in the treatment of T2DM by using network pharmacology method and molecular docking.. Retrieving and screening of active components of different herbs in HLJDD and corresponding T2DM-related target genes across multiple databases. Subsequently, STRING and Cytoscape were applied to analysis and construct PPI network. In addition, cluster and topological analysis were employed for the analysis of PPI networks. Then, the GO and KEGG enrichment analysis were performed by using ClueGO tool. Finally, the differentially expressed analysis was used to verify whether the expression of key target genes in T2DM and non-T2DM samples was statistically significant, and the binding capacity between active components and key targets was validated by molecular docking using AutoDock.. There are 65 active components involved in 197 T2DM-related targets that are identified in HLJDD formula. What is more, 39 key targets (AKT1, IL-6, FOS, VEGFA, CASP3, etc.) and 3 clusters were obtained after topological and cluster analysis. Further, GO and KEGG analysis showed that HLJDD may play an important role in treating T2DM and its complications by synergistically regulating many biological processes and pathways which participated in signaling transduction, inflammatory response, apoptotic process, and vascular processes. Differentially expressed analysis showed that AKT1, IL-6, and FOS were upregulated in T2DM samples and a significant between sample differential expression. These results were validated by molecular docking, which identified 5 high-affinity active components in HLJDD, including quercetin, wogonin, baicalein, kaempferol, and oroxylin A.. Our research firstly revealed the basic pharmacological effects and relevant mechanisms of the HLJDD in the treatment of T2DM and its complications. The prediction results might facilitate the development of HLJDD or its active compounds as alternative therapy for T2DM. However, more pharmacological experiments should be performed for verification. Topics: Apoptosis; China; Cluster Analysis; Diabetes Mellitus, Type 2; Drugs, Chinese Herbal; Flavanones; Flavonoids; Gene Expression Profiling; Humans; Inflammation; Interleukin-6; Kaempferols; Medicine, Chinese Traditional; Molecular Docking Simulation; Protein Interaction Mapping; Proto-Oncogene Proteins c-akt; Quercetin | 2020 |
Oroxylin A, a methylated metabolite of baicalein, exhibits a stronger inhibitory effect than baicalein on the CYP1B1-mediated carcinogenic estradiol metabolite formation.
Topics: Breast Neoplasms; Carcinogenesis; Carcinogens; Cytochrome P-450 CYP1B1; Down-Regulation; Estradiol; Estrogens, Catechol; Female; Flavanones; Flavonoids; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; MCF-7 Cells | 2019 |
Establishment of rat liver microsome-hydrogel system for in vitro phase II metabolism and its application to study pharmacological effects of UGT substrates.
Studies on the efficacy evaluation of UDP-glucuronosyltransferases (UGTs) substrates often ignore the existence of active metabolites. However, the present study aims to establish an in-vitro Phase II metabolism system to predict their pharmacological effects after metabolism. Rat liver microsomes (RLMs) encapsulated in a F127'-Acr-Bis (FAB) hydrogel were placed in the incubation system. Baicalein (BA) was chosen as a model drug and the metabolic activity was investigated by quantitating the metabolite Baicalin (BG). The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was used to measure the cell viability in Traditional cell culture system (TCCS) and Microsome-hydrogel added to cell culture system for Phase II metabolism (MHCCS-II). Finally, MHCCS-II was applied to predict the metabolic effects of Oroxylin A (OA) and Wogonin (W). Compared to TCCS group, for HepG2 and MCF-7 cells, BA in MHCCS-II led to lower survival ratios of cells (P < 0.05), while for PC12 cells it led to higher survival ratios of cells (P < 0.01). For HepG2 cells, OA and W showed obviously enhanced tumor inhibition after metabolism with the IC Topics: Animals; Antineoplastic Agents; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Flavanones; Flavonoids; Glucuronosyltransferase; Humans; Hydrogels; Metabolic Detoxication, Phase II; Microsomes, Liver; Molecular Structure; Rats; Structure-Activity Relationship; Tumor Cells, Cultured | 2019 |
Synergistic effect of baicalein, wogonin and oroxylin A mixture: multistep inhibition of the NF-κB signalling pathway contributes to an anti-inflammatory effect of Scutellaria root flavonoids.
Scutellaria root, the root of Scutellaria baicalensis Georgi, is a crude drug used for inflammatory diseases. In our previous report, the combination of flavonoids contained in Scutellaria root have been found to inhibit PGE Topics: Drugs, Chinese Herbal; Flavanones; Flavonoids; Humans; NF-kappa B; Scutellaria; Scutellaria baicalensis; Transfection | 2018 |
A metabolomic approach to identify anti-hepatocarcinogenic compounds from plants used traditionally in the treatment of liver diseases.
Topics: Andrographis; Antineoplastic Agents, Phytogenic; Apigenin; Apocynaceae; Asia, Southeastern; Biflavonoids; Bignoniaceae; Catechin; Diterpenes; Ethnopharmacology; Flavanones; Flavonoids; Hep G2 Cells; Humans; Lamiaceae; Liver Neoplasms; Metabolomics; Plants, Medicinal; Proanthocyanidins | 2018 |
Baicalin protects mice against Salmonella typhimurium infection via the modulation of both bacterial virulence and host response.
The worsening problems of antibiotic resistance prompt the need for alternative strategies. Baicalin, which is isolated from Scutellaria baicalensisi, has been demonstrated to exhibit anti-inflammatory, anti-virulence and antimicrobial effects. Salmonella typhimurium is an important foodborne pathogenic bacteriaum that causes gastrointestinal disease in humans and many animals.. The aim of this study was to investigate the effects of baicalin on S. typhimurium infection in mice and its possible mechanism in vitro.. To evaluate the effect of baicalin in vivo, mice were orally administered of baicalin, and then were infected by an intragastric administration of S. typhimurium. The minimal inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of baicalin, baicalein, and oroxylin A against S. typhimurium were detected under the guides of the Clinical and Laboratory Standards Institute. In vitro, Caco-2 cells were infected with S. typhimurium in the presence or absence of baicalin, baicalein, and oroxylin A at sub-MICs.. In the in vivo experiment, the body weight loss, the serum levels of TNFα, IL-6, and lactic dehydrogenase (LDH), the pathological changes of the caecum and the caecum bacterial burdens were examined. The MICs and MBCs of baicalin, baicalein, and oroxylin A against S. typhimurium were detected by two-fold serial dilutions. In vitro, Caco-2 cells were infected with S. typhimurium, and the invasion capacity, TNFα, nitrate, and LDH were analysed. The transcription levels of Salmonella pathogenicity island 1 virulence associated genes (sopB, sopE, sopE2) of S. typhimurium in the presence of baicalin, baicalein, and oroxylin A were detected by qRT-PCR.. Our results showed that baicalin significantly decreased the body weight loss, the serum levels of TNFα, IL-6, and LDH, and the caecum bacterial burdens of mice challenged with S. typhimurium. Histological examination showed that baicalin decreased the lesion in the caecum of S. typhimurium-infected mice. MICs and MBCs of baicalin, and oroxylin A. against S. typhimurium were > 128 µg/ml. MICs and MBCs of baicalein against S. typhimurium were 64 µg/ml, and > 128 µg/ml, respectively. Pretreatment of Caco-2 cells or S. typhimurium with baicalin, baicalein, and oroxylin A significantly inhibited the invasion of Caco-2 cells by S. typhimurium in a dose-dependent manner. Sub-MICs of baicalin, baicalein, and oroxylin A also significantly decreased the levels of TNFα, nitrate, and LDH from S. typhimurium-infected Caco-2 cells. Moreover, the transcription levels of sopB, sopE, and sopE2 were significantly suppressed by baicalin, baicalein, and oroxylin A.. These results demonstrated that baicalin is a promising agent for the prevention of S. typhimurium infection via the modulation of both bacterial virulence and host response. Topics: Animals; Anti-Bacterial Agents; Caco-2 Cells; Flavanones; Flavonoids; Humans; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Plant Extracts; Salmonella Infections, Animal; Salmonella typhimurium; Scutellaria; Virulence | 2018 |
Brain Uptake of Bioactive Flavones in Scutellariae Radix and Its Relationship to Anxiolytic Effect in Mice.
Scutellariae Radix (SR) and its bioactive flavones elicit a variety of effects in the brain. However, the brain uptake of individual SR flavones and its relationship to the elicited effects after SR administration remain unknown. Moreover, previous studies seldom measured pharmacokinetic and pharmacodynamic outcomes simultaneously. In the current study, the brain uptake of six major SR flavones and the anxiolytic behavior following oral administration of a SR extract at two clinically relevant doses (600 and 1200 mg/kg twice daily) were simultaneously investigated in mice (n = 18 per group). Brain and plasma concentrations of the flavones were measured by LC-MS/MS, while the anxiolytic effect was evaluated using the elevated plus maze. To further investigate the mechanism behind the differential brain uptake of the six SR flavones, these flavones were separately administered to mice at an equivalent molar oral dose (n = 6). The brain tissue bindings of the SR flavones were also measured with the in vitro brain slice method. Our results indicated that all six SR flavones including three aglycons (baicalein, wogonin, and oroxylin A) and three glucuronides (baicalin, wogonoside, and oroxyloside) could pass through the blood-brain barrier, with brain concentrations ranging from 7.9 to 224.0 pmol/g. It provided novel evidence that oroxylin A had the highest brain uptake among the six SR flavones regardless of its limited content in SR extract, in which 3.6-3.9% of the administered oroxylin A dose was present in the brain 6 h postdosing and with a brain-to-plasma ratio of 0.42-0.46. Although SR extract contains flavones that are positive modulators of the benzodiazepine binding site of GABA Topics: Animals; Anti-Anxiety Agents; Brain; Flavanones; Flavones; Flavonoids; Glucosides; Male; Maze Learning; Mice; Mice, Inbred ICR; Scutellaria baicalensis; Tandem Mass Spectrometry | 2017 |
Enhancement of solubility and dissolution rate of baicalein, wogonin and oroxylin A extracted from Radix scutellariae.
Baicalein, wogonin, and oroxylin A are three major hydrophobic components in the extract of Radix scutellariae with wide spectrum of pharmacological applications. The purpose of this study was to enhance the solubility, dissolution rate and stability of baicalein, wogonin and oroxylin A by solid dispersion (SD) technique. SD of the extract with various polymers was prepared to select the best carrier. Solubility study, chemical stability study and dissolution study were performed to characterize the SD. The solubility of all three components, after forming solid dispersion with povidone K-30 (PVP K-30) was significantly increased in pH 6.8 medium at room temperature. Stability study conducted for 80days elucidated that the SD in powder state was fairly stable without the aid of Vitamin C (VC). VC was required as antioxidant to impart stability to baicalein in aqueous medium. The dissolution test of the SD of three components, admixed with VC at the weight ratio of 1:6 (Radix scutellariae extract: VC, w/w) exhibited faster dissolution rate with 100% release of all components. Pharmacokinetic study of baicalein solid dispersion revealed that AUC and C Topics: Drug Stability; Flavanones; Flavonoids; Scutellaria; Solubility | 2017 |
Screening of six Ayurvedic medicinal plants for anti-obesity potential: An investigation on bioactive constituents from Oroxylum indicum (L.) Kurz bark.
As an effort to identify newer anti-obesity lead(s) we have selected 13 plant materials from the six plant species which have been reported in Indian Ayurvedic medicine as remedy against complications affecting glucose and lipid homeostasis.. In vitro screening of six Indian Ayurvedic medicinal plants on anti-adipogenic and pancreatic lipase (PL) inhibition potential followed by bioactivity guided isolation from most active plant material.. In vitro anti-adipogenic assay using 3T3-L1 preadipocytes and pancreatic lipase (PL) inhibition assay were performed for hexanes, dichloromethane, ethyl acetate and methanolic extracts of all the plant materials. Bioactivity guided isolation approach was used to identify active constituent for anti-adipogenesis and PL inhibition assay. Inhibition of lipid accumulation and adipogenic transcription factor was measured by oil Red 'O' staining and quantitative real-time PCR method respectively.. Ethyl acetate extract of Oroxylum indicum bark was found to be most active in screening of anti-adipogenesis (59.12±1.66% lipid accumulation as compared to control at 50μg/mL dose) and PL inhibition (89.12±6.87% PL inhibition at 250μg/mL dose) assays. Further, three bioactive flavonoids were isolated and identified as oroxylin A, chrysin and baicalein from O. indicum bark. Oroxylin A, chrysin, and baicalein were inhibited lipid accumulation in 3T3-L1 preadipocytes (75.00±5.76%, 70.21±4.23% and 77.21±5.49% lipid accumulation respectively in comparison to control at 50μM dose) and PL enzyme (69.86±2.96%, 52.08±2.14% and 45.06±2.42% PL inhibition respectively at 250μg/mL dose). In addition, oroxylin A and chrysin also inhibited PPARγ and C/EBPα, major adipogenic transcription factors, in 3T3L-1 preadipocytes during adipogenesis process at 50μM dose.. The present study augurs the anti-obesity potential of well practiced Ayurvedic herb O. indicum and its flavonoids. Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Animals; Anti-Obesity Agents; Bignoniaceae; CCAAT-Enhancer-Binding Protein-alpha; Cell Line; Flavanones; Flavonoids; India; Lipase; Medicine, Ayurvedic; Mice; Obesity; Plant Bark; Plant Extracts; Plants, Medicinal; PPAR gamma | 2017 |
Distribution patterns of the contents of five biologically activate ingredients in the root of Scutellaria baicalensis.
As an important herbaceous plant, Scutellaria baicalensis Georgi (Chinese skullcap) is geographically widespread and commonly used throughout the world. In the Chinese medicine market, S. baicalensis has been divided into two primary types, "Ku Qin" (WXR) and "Tiao Qin" (TST). Moreover, TST is also divided into different grades according to the diameter of roots. To explore the distribution patterns of the contents of five biologically activate ingredients (FBAI), we used six-year-old cultivated S. baicalensis and analyzed its growth characteristics as well as the quality difference among different types and diameters in roots. Throughout the entire root, we discovered that contents of the FBAI all initially increased and subsequently decreased from the top to the bottom of the roots. The baicalin content of WXR was less than that of TST. On the contrary, the contents of baicalein, wogonin, and oroxylin A in WXR were up to about two times higher than that in TST. We also found that the 0 to 40 cm part of the S. baicalensis root possessed about 87% of the root biomass and about 92% of the contents of the active ingredients. Topics: Drugs, Chinese Herbal; Flavanones; Flavonoids; Plant Roots; Scutellaria baicalensis | 2017 |
Enzymatic production of oroxylin A and hispidulin using a liverwort flavone 6-O-methyltransferase.
Oroxylin A and hispidulin, compounds which are abundant in both Scutellaria and liverwort species, are important lead compounds for the treatment of ischemic cerebrovascular disease. Their enzymatic synthesis requires an O-methyltransferase able to interact with the related flavonoid's 6-OH group, but such an enzyme has yet to be identified in plants. Here, the gene encoding an O-methyltransferase (designated PaF6OMT) was isolated from the liverwort species Plagiochasma appendiculatum. A test of alternative substrates revealed that its strongest preferences were baicalein and scutellarein, which were converted into, respectively, oroxylin A and hispidulin. Allowed a sufficient reaction time, the conversion rate of these two substrates was, respectively, 90% and 100%. PaF6OMT offers an enzymatic route to the synthesis of oroxylin A and hispidulin. Topics: Apigenin; Cerebrovascular Disorders; Cloning, Molecular; Flavanones; Flavones; Flavonoids; Hepatophyta; Humans; Methyltransferases; Substrate Specificity | 2016 |
Effects of Lead Phytochemicals of Radix Scutellariae on Acanthamoeba.
Acanthamoeba keratitis (AK), which is associated with noncompliant use of contact lenses, remains difficult to treat due to delayed diagnosis and paucity of therapeutic agents. Although improvements in activity against Acanthamoeba infection have been achieved in disinfecting solutions for soft contact lenses, such modifications have not been extended to those for special rigid gas permeable (RGP) contact lenses, which are increasingly used for myopia control in children. Phytochemicals present in herbs used for traditional Chinese medicine may be effective as therapeutic or preventive agents. The purpose of this study was to investigate amoebicidal properties of lead phytochemicals of Radix scutellariae alone and in combination with multipurpose (disinfecting) solutions (MPS) for RGP lenses.. Viability of Acanthamoeba castellani and A. polyphaga trophozoites was determined following exposure to four phytochemicals: baicalin, baicalein, wogonoside, and oroxylin A and both alone and in combination with four RGP MPS, using a modified stand-alone technique.. As individual agents, wogonoside and oroxylin A showed highest activity against A. castellani and A. polyphaga trophozoites, respectively. For both organisms, the combination of baicalein and oroxylin A was superior. Effectiveness of MPS alone did not exceed 0.27 log reduction, but addition of combined baicalein and oroxylin A resulted in 0.92 and 0.64 log reductions of A. castellani and A. polyphaga, respectively.. The combination of baicalein and oroxylin A enhanced the activity of MPS for RGP contact lenses against trophozoites of two pathogens, A. castellani, and A. polyphaga, and offers a potential therapeutic and/or preventative agent for AK. Topics: Acanthamoeba; Acanthamoeba Keratitis; Animals; Antioxidants; Contact Lens Solutions; Contact Lenses, Hydrophilic; Disinfectants; Disinfection; Flavanones; Flavonoids; Lead; NAD(P)H Dehydrogenase (Quinone); Phytochemicals | 2016 |
Influence of mefenamic acid on the intestinal absorption and metabolism of three bioactive flavones in Radix Scutellariae and potential pharmacological impact.
Mefenamic acid (MEF) and the dried root of Scutellaria baicalensis Georgi (Radix Scutellariae, RS) share a high possibility of combined medication to treat inflammation.. The present study investigates the impact of MEF on absorption/disposition of three major components in RS (baicalein, B; wogonin, W; oroxylin A, OA) and further pharmacological changes.. The apparent permeability (P(app)) and percentage of metabolism of B, W and OA at 10 μΜ were measured at the absence/presence of MEF (100 μΜ) in the Caco-2 cell monolayer model. A modified whole blood assay was employed to quantify prostaglandin E₂ (PGE₂) 4, 6 and 8 h post-oral administration with water suspension of MEF at 40 mg/kg and RS at 200 mg/kg.. In the presence of MEF, Papp of B, W and OA were increased from 1.69 ± 0.89 × 10⁻⁶, 1.57 ± 0.10 × 10⁻⁶ and 3.09 ± 0.70 × 10⁻⁶ cm/sec to 5.24 ± 0.27 × 10⁻⁶, 6.08 ± 0.19 × 10⁻⁶ and 4.13 ± 0.38 × 10⁻⁶, whereas their percentage of metabolism was decreased from 72.75 ± 2.44%, 73.27 ± 3.25% and 89.84 ± 2.99% to 21.11 ± 0.69%, 17.90 ± 5.55% and 45.44 ± 3.38%. PGE2 level was much lower in the co-administration group (49.04 ± 2.03 pg/ml) than in the MEF group (73.13 ± 3.03 pg/ml) or RS group (494.37 ± 11.75 pg/ml) 4 h post MEF dosing, suggesting a synergic effect.. Co-administration of MEF and RS could induce potential alterations in their pharmacokinetic profiles and anti-inflammatory effects. Topics: Animals; Anti-Inflammatory Agents; Caco-2 Cells; Drug Interactions; Drug Synergism; Flavanones; Flavonoids; Humans; Intestinal Absorption; Male; Mefenamic Acid; Plant Extracts; Plant Roots; Rats; Rats, Sprague-Dawley; Scutellaria baicalensis; Time Factors | 2014 |
Species difference in the inhibitory potentials of non-steroidal anti-inflammatory drugs on the hepatic sulfation and glucuronidation of bioactive flavonoids: differential observations among common inhibition parameters.
1. This study elucidated the species differences between rats and humans in the inhibitory potential of drugs against sulfation and glucuronidation, and whether such differences depend on the inhibition parameter adopted. 2. With 14 non-steroidal anti-inflammatory drugs (NSAIDs) as model inhibitors and three flavanoids baicalein, wogonin and oroxylin A as model substrates, three common inhibition parameters percentage of control, IC50 and Ki were determined in rat liver cytosols (RLCs), human liver cytosols (HLCs), rat liver microsomes (RLMs) and human liver microsomes (HLMs). The closeness of the inhibition parameters from rat liver preparations to that from human liver preparations was analyzed by geometric mean fold error (GMFE) and statistical comparisons. 3. The percentage of control in RLC/RLM was not significantly different from that in HLC/HLM, with a GMFE of 0.85 (RLC-HLC) and 1.03 (RLM-HLM); whereas the IC50 and Ki in RLC/RLM were significantly different from that in HLC/HLM. The trend of difference was consistent between IC50 and Ki, where these parameters in RLC and RLM underestimated (GMFE <0.5) and overestimated (GMFE >2) that in HLC and HLM, respectively. 4. In conclusion, the inhibitory potentials of NSAIDs against sulfation and glucuronidation in rats and humans were different and depended on the adopted inhibition parameters. Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cytosol; Dose-Response Relationship, Drug; Flavanones; Flavonoids; Humans; Inhibitory Concentration 50; Liver; Microsomes, Liver; Rats; Species Specificity | 2014 |
Development of a SPE-LC/MS/MS method for simultaneous quantification of baicalein, wogonin, oroxylin A and their glucuronides baicalin, wogonoside and oroxyloside in rats and its application to brain uptake and plasma pharmacokinetic studies.
This study aims to identify and quantify the six major bioactive flavones of the traditional Chinese medicine Scutellariae Radix (RS), including baicalein, baicalin, wogonin, wogonoside, oroxylin A and oroxyloside in rat after oral administration of a standardized RS extract. A novel, sensitive and selective method for simultaneous determination of these six analytes in rat brain and plasma using solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC/MS/MS) was developed and fully validated. The lower limits of quantification (LLOQs) for the six RS flavones in brain tissue were 0.02nmol/g. The LLOQs in plasma were 0.005nmol/ml for B, W and OA, 0.025nmol/ml for WG and OAG, and 0.1875nmol/ml for BG. The current study provides novel evidence of the presence of all the tested RS flavones and an isoform of BG (BG', probably baicalein-6-O-glucuronide) in the rat brain after oral administration of RS extract, suggesting their ability to permeate through the blood-brain barrier. The method was also successfully applied to the pharmacokinetic study of all these analytes in plasma after oral administration of RS extract (300mg/kg) to Sprague-Dawley rats. The developed assay method provides a useful tool for both preclinical and clinical investigations on the disposition of RS flavones in brain and plasma. Topics: Animals; Brain; Chromatography, Liquid; Flavanones; Flavones; Flavonoids; Glucosides; Glucuronides; Male; Rats; Solid Phase Extraction; Tandem Mass Spectrometry | 2014 |
[Pharmacokinetics and pharmacodynamics of huangqin tang in febrile rats].
The pharmacodynamic (PD) and pharmacokinetic (PK) properties of Huangqin Tang (HQT) were investigated in yeast-induced febrile rats. Blood sample and rectal temperature data of the rats were collected at different times after single oral administration of HQT at 20 g x kg(-1). The plasma concentrations of paeoniflorin, baicalin, wogonoside, baicalein, wogonin, oroxylin A, glycyrrhizic acid and glycyrrhetinic acid were quantified by a sensitive liquid chromatography-tandem mass spectrometric (LC-MS) method. The blood concentrations of PGE2, 1L-1β and TNF-α were detected by radioimmunoassay (RIA). All pharmacokinetic parameters were processed by non-compartmental analysis using WinNonlin software. The potential relationship between the mean concentration of eight constituents and the antifebrile efficacy was investigated by calculating Pearson correlation coefficients. It was found that HQT had significant antifebrile efficacy in yeast-induced febrile rats, but had no effect to normal rats. The antifebrile effect of HQT can be attributed to the inhibition of PGE2, 1L-1β and TNF-α. The constituents (baicalin, wogonoside, baicalein, wogonin, oroxylin A, glycyrrhizic acid and glycyrrhetinic acid) in febrile rats had delayed absorption and elimination, a longer residence time in the body, and higher C(max) and AUC than those in normal rats. Febrile condition could affect the pharmacokinetic behaviour of HQT in vivo; the flavonoids with the same backbone showed the similar fate in the body; baicalein and wogonin had a strong positive correlation (R > 0.66, P ≤ 0.02) with the antifebrile efficacy determined. Together, these constituents demonstrated different pharmacokinetic properties in the febrile body. Topics: Administration, Oral; Animals; Area Under Curve; Chromatography, Liquid; Dinoprostone; Drugs, Chinese Herbal; Fever; Flavanones; Flavonoids; Glucosides; Interleukin-1beta; Mass Spectrometry; Monoterpenes; Rats; Tumor Necrosis Factor-alpha | 2014 |
[LC-MS quantification and pharmacokinetics of the multi-constituents of Huangqin Tang in rat plasma after different single oral doses].
The current study aims to investigate the pharmacokinetic properties of Huangqin Tang on different oral doses. An LC-MS method for simultaneous determination of flavonoids and terpenoids in rat plasma was developed and validated. Plasma samples were treated with hydrochloric acid (containing 1% ascorbic acid), precipitated with acetonitrile, separated on a Zorbax SB-C18 column, detected by single quadruple mass spectrometry with an electrospray ionization interface, and quantified using selected ion monitoring mode. All pharmacokinetic parameters were processed by non-compartmental analysis using WinNonlin software. The results of specificity, linearity, intra-day and inter-day precisions, accuracy, and stability for LC-MS assay were suitable for the quantification of paeoniflorin, baicalin, wogonoside, baicalein, wogonin, oroxylin A, glycyrrhizic acid and glycyrrhetinic acid in rat plasma. The concentration-time profiles of baicalin, wogonoside, baicalein, wogonin, oroxylin A and glycyrrhizic acid showed double-peak phenomenon after Huangqin Tang was orally administered at 40 g x kg(-1) dose; all eight constituents in rat plasma showed good dose-exposure relationship within the dosage of 10-40 g x kg(-1); although plasma concentrations were different, the flavonoids with the same backbone showed the similar fate in the body with the corresponding dosage. In conclusion, the LC-MS assay was successfully applied for the pharmacokinetic study of multi-constituents of Huangqin Tang with different doses. Additionally, these constituents demonstrated good pharmacokinetic properties in the body. Topics: Administration, Oral; Animals; Chromatography, Liquid; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Flavanones; Flavonoids; Glucosides; Glycyrrhetinic Acid; Glycyrrhizic Acid; Male; Monoterpenes; Pentacyclic Triterpenes; Rats; Rats, Wistar; Spectrometry, Mass, Electrospray Ionization | 2013 |
Detection of baicalin metabolites baicalein and oroxylin-a in mouse pancreas and pancreatic xenografts.
Scutellaria baicalensis has been a subject of research interest due to its potential multiple therapeutic benefits. This study was to examine the distribution of baicalein, wogonin, oroxylin A and their glucuronide/sulfate-conjugated metabolites in plasma, colon, small intestine, lung, liver, pancreas, kidney, and prostate tissues and in pancreatic tumor in a xenograft animal model. In addition, we examined metabolic stability of baicalin in these tissues.. A mouse xenograft model was prepared by injection of 3 × 10 human pancreatic cancer MiaPaCa-2 cells subcutaneously into nude mice. Mice were randomly allocated to control diet (AIN-76A) and 1% S. baicalensis diet (n = 8 per group) for 13 weeks. Levels of baicalein, wogonin, oroxylin A, and their conjugates in mouse tissues were measured by high-pressure liquid chromatography after enzymatic hydrolysis and then extraction.. A substantial amount of baicalin (34%-63%) was methylated to oroxylin A and its conjugates in various organs during absorption. Whereas plasma contained predominantly conjugates of baicalein, wogonin, and oroxylin A, both aglycones and conjugates were found in all other tissues investigated and in tumor.. Substantial accumulation of bioactive metabolites are found in target tissues, suggesting strong potential for S. baicalensis use as a preventive or adjuvant supplement for pancreatic cancer. Topics: Animals; Biological Availability; Cell Line, Tumor; Chromatography, High Pressure Liquid; Diet; Flavanones; Flavonoids; Mice; Mice, Nude; Pancreas; Pancreatic Neoplasms; Plant Extracts; Plant Roots; Random Allocation; Scutellaria baicalensis | 2012 |
Comparison of intestinal absorption and disposition of structurally similar bioactive flavones in Radix Scutellariae.
Radix Scutellariae is a commonly used herbal medicine. Baicalein, wogonin, and oroxylin A are three major bioactive flavones in Radix Scutellariae and share similar chemical structures. The intestinal absorption and disposition of baicalein have been systematically investigated by our group before. In this study, the intestinal absorption and disposition of wogonin and oroxylin A were further explored and compared with the profiles of baicalein to find potential structure-activity relationship. Absorptive models including Caco-2 cell monolayer model and rat in situ single-pass intestinal perfusion model as well as in vitro enzymatic kinetic study were employed in the current study. The absorption of baicalein, wogonin, and oroxylin A were favorable with wogonin showing the highest permeability based on two absorptive models. However, three flavones underwent a fast and extensive phase II metabolism. The intestinal metabolism of three flavones exhibited species difference between human and rat. Oroxylin A demonstrated the highest intrinsic clearance of glucuronidation among three flavones. The multidrug resistance proteins might be involved in the efflux of their intracellularly formed conjugated metabolites. The pathway of intestinal absorption and disposition of B, W, and OA was similar. However, the extent of permeability and metabolism was different among three flavones which might be due to the number and position of the hydroxyl group. Topics: Animals; Caco-2 Cells; Flavanones; Flavonoids; Glucuronides; Humans; Intestinal Absorption; Male; Permeability; Rats; Rats, Sprague-Dawley; Scutellaria baicalensis; Species Specificity; Structure-Activity Relationship | 2012 |
Simultaneous determination of baicalin, wogonoside, baicalein, wogonin, oroxylin A and chrysin of Radix scutellariae extract in rat plasma by liquid chromatography tandem mass spectrometry.
A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of baicalin, wogonoside, baicalein, wogonin, oroxylin A and chrysin in rat plasma, using naringin as an internal standard. After acidifying with HCl, plasma samples were pretreated by liquid-liquid extraction with acetone. Chromatographic separation was accomplished on a Hypersil Gold-C(18) analytical column (2.1×150 mm, 5 μm) utilizing a gradient elution profile and a mobile phase consisting of (A) 0.1% formic acid in water and (B) acetonitrile. Detection was performed by multiple reaction monitoring (MRM) mode using electrospray ionization in the positive ion mode. All analytes showed good linearity over the investigated concentration range (r>0.9900). The lower limit of quantification was 0.5 ng/ml for baicalin, wogonoside, wogonin and oroxylin A, and 1.0 ng/ml for baicalein and chrysin. Intra-day and inter-day precisions (RSD%) were less than 15% and accuracy (RE%) ranged from -6.7% to 5.8%. The validated method was successfully applied to investigate the pharmacokinetics of the major flavonoids of Radix scutellariae extract after oral administration to rats. Topics: Administration, Oral; Animals; Area Under Curve; Chromatography, Liquid; Drugs, Chinese Herbal; Flavanones; Flavonoids; Glucosides; Half-Life; Limit of Detection; Male; Metabolic Clearance Rate; Plant Extracts; Rats; Rats, Wistar; Reference Standards; Reproducibility of Results; Scutellaria baicalensis; Sensitivity and Specificity; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry | 2012 |
Identification and quantification of baicalein, wogonin, oroxylin A and their major glucuronide conjugated metabolites in rat plasma after oral administration of Radix scutellariae product.
The current study aims to identify and quantify three flavones (baicalein, wogonin and oroxylin A) and their major metabolites (baicalin, wogonoside and oroxylin A-7-O-glucuronide) in rat plasma after oral administration of Radix scutellariae product. A simple HPLC/UV method has been developed to simultaneously determine the three flavones and their major metabolites in rat plasma. The chromatographic separation of the six analytes was achieved by a Thermo C(18) column with linear gradient elution of a mobile phase containing acetonitrile and 20mM sodium dihydrogen phosphate buffer (pH 4.6). All the tested analytes were detected by PDA detector at a wavelength of 320nm. The intra-day and inter-day precision for the current assay of the six analytes was within the range of -2.23% to 15.13% and -10.83% to 6.42%, respectively. All the studied analytes could be efficiently extracted from the rat plasma using HLB cartridge with extraction recoveries above 70% and were stable under different storage conditions. The developed assay method was successfully applied to the pharmacokinetic study of baicalin, wogonoside after oral administration of a commercially available Radix scutellariae containing capsule at a dose of 3.2g/kg to Sprague-Dawley rats. In addition to wogonoside, a new metabolite of wogonin has been identified using LC/MS/MS for the first time. Topics: Administration, Oral; Animals; Chromatography, High Pressure Liquid; Drug Stability; Drugs, Chinese Herbal; Flavanones; Flavonoids; Glucuronides; Limit of Detection; Male; Molecular Structure; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Scutellaria baicalensis; Solid Phase Extraction; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry | 2011 |
Anti-pruritic effect of baicalin and its metabolites, baicalein and oroxylin A, in mice.
To explore whether intestinal microflora plays a role in anti-pruritic activity of baicalin, a main constituent of the rhizome of Scutellaria baicalensis (SB).. Baicalin was anaerobically incubated with human fecal microflora, and its metabolites, baicalein and oroxylin A, were isolated. The inhibitory effect of baicalin and its metabolites was accessed in histamine- or compound 48/80-induced scratching behavior in mice.. Baicalin was metabolized to baicalein and oroxylin A, with metabolic activities of 40.2+/-26.2 and 1.2+/-1.1 nmol.h(-1).mg(-1) wet weight of human fecal microflora, respectively. Baicalin (20, 50 mg/kg) showed more potent inhibitory effect on histamine-induced scratching behavior when orally administered than intraperitoneally. In contrast, baicalein and oroxylin A had more potent inhibitory effect when the intraperitoneally administered. The anti-scratching behavior activity of oral baicalin and its metabolites was in proportion to their inhibition on histamine-induced increase of vascular permeability with oroxylin A more potent than baicalein and baicalin. In Magnus test using guinea pig ileum, oroxylin A is more potent than baicalein and baicalin in inhibition of histamine-induced contraction. The anti-scratching behavioral effect of oral baicalin was significantly reduced when oral antibiotics were simultaneously administered, whereas the effect of baicalein and oroxylin A were not affected.. Oral baicalin may be metabolized by intestinal microflora into baicalein and oroxylin A, which ameliorate pruritic reactions through anti-histamine action. Topics: Animals; Anti-Bacterial Agents; Antipruritics; Feces; Flavanones; Flavonoids; Guinea Pigs; Histamine; Histamine Antagonists; Intestines; Male; Mice; Mice, Inbred BALB C; Mice, Inbred ICR; Phytotherapy; Pruritus; Scutellaria baicalensis; Streptomycin; Tetracycline | 2010 |
Synthesis and biological evaluation of novel benzyl-substituted flavones as free radical (DPPH) scavengers and α-glucosidase inhibitors.
Pharmacologically motivated natural product investigations have yielded a large variety of structurally unique lead compounds with interesting biomedical properties, but the natural roles of these molecules often remain unknown. In the present investigation, a series of benzyl substituted-flavone derivatives have been synthesized from the lead compounds and were screened against 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and α-glucosidase inhibitory properties. The resulting activity profiles of these flavone derivatives were compared for degree of similarity to the profile of 1-3. Most of the synthesized derivatives displayed potent activities when compared to the parent compounds. Maximum potencies for DPPH free radical scavenging activity were observed only in compounds containing the 4-hydroxyl substitution and 3-methoxyl group on the phenyl ring. While the 2- and 4-hydroxyl group substitutions on the phenyl ring seem to be crucial for the intestinal α-glucosidase inhibitory activity. Topics: Benzene Derivatives; Bignoniaceae; Biphenyl Compounds; Flavanones; Flavonoids; Free Radical Scavengers; Glycoside Hydrolase Inhibitors; Hypoglycemic Agents; India; Molecular Structure; Picrates; Plant Roots; Plants, Medicinal | 2010 |
[Flavonoids from Scutellaria baicalensis and their bioactivities].
To study the flavonoids of Scutellaria baicalensis and their bioactivities.. Chromatographic methods were used to separate compounds, spectral methods were used to determine the structures and bioactivities of the flavonoids were screened in several models in vitro.. Nine compounds were isolated and identified as baicalein (1), wogonin (2), oroxylin A (3), 5, 7, 2', 6'-tetrahydroxyflavone (4), viscidulin III (5), baicalin (6), wogonoside (7), oroxylin A-7-O-beta-D-glucuronide (8) and chrysin-6-C-alpha-L-arabinopyranosyl-8-C-beta-D-glucopyranoside (9).. Baicalein had good anti-bacteria activity, and some compounds showed inhibiting activity against IL-1beta converting enzyme. The 13C NMR data of compounds 9 were assigned correctly by 2D nuclear magnetic resonance (NMR). Topics: Anti-Bacterial Agents; Caspase Inhibitors; Flavanones; Flavonoids; Glucosides; Scutellaria baicalensis | 2009 |
Impacts of baicalein analogs with modification of the 6th position of A ring on the activity toward NF-kappaB-, AP-1-, or CREB-mediated transcription.
The water extract of Scutellariae baicalensis Georgi (S. baicalensis) has potential anti-tumor and anti-inflammatory activities. A major flavonoid isolated from S. baicalensis, baicalein, was also found to have anti-tumor and anti-inflammatory activities. These biological activities could be due to their antioxidant action and/or effect on different signal transduction pathways. We investigated the effects of several baicalein analogs with a substitution of hydrogen of the hydroxyl group at the 6th position of A ring on three signal pathway mediated transcription (NF-kappaB, AP-1, and CREB) associated with inflammation and cancer growth. We found that the analogs with O-alkyl group of the different carbon chain length or O-benzyl activated NF-kappaB transcription without TNFalpha stimulation. Some of the analogs increased TNFalpha stimulated NF-kappaB transcription by two- to threefold. None of the analogs studied has major effect on AP-1 signal transduction with or without TPA stimulation. All of the analogs increased CREB transcription with forskolin stimulation up to twofold. However, they did not have a potent effect (less or about twofold activation) on intrinsic CREB signal transduction. The modification of baicalein at the 6th position of A ring was not correlated with change in these signal transduction pathways and cytotoxicity. Though, they are structural analogs, they are not functional analogs. Modification of baicalein at the 6th position could alter the specificity of action toward different cellular targets. Flavonoids could be chemophores in the development of drugs targeted at different signal transcriptional pathway. Topics: Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents, Phytogenic; Cyclic AMP Response Element-Binding Protein; Drug Design; Flavanones; Molecular Structure; NF-kappa B; Plants, Medicinal; Scutellaria baicalensis; Structure-Activity Relationship; Tetradecanoylphorbol Acetate; Transcription Factor AP-1 | 2008 |
[Studies on ethyl acetate soluble constituents of Huanglian Jiedutang].
To study the ethyl acetate soluble constituents from the water extractive of Huanglian Jiedutang decoction, which are composed of Rhizoma Coptidis, Radix Scutellariae, Cortex Phellodendri and Fructus Gardeniae, and provide substances foundation for its pharmacokinetic and pharmacodynamic investigation.. The chemical constituents were isolated by various column chromatographic methods and structurally elucidated by NMR and MS techniques.. Thirty-five compounds were isolated, among which twenty compounds have been identified as beta-sitosterol (1), oroxylin A (2), wogonin (3), ursolic acid (4), skullcapflavone I (5), tenaxin I (6), skullcapflavone II (7), limonin (8), 5, 2'-dihydroxy-6, 7, 8, 3'-tetramethoxyflavone (9), chrysin (12), baicalein (17), tenaxin II (19), 5, 7, 2'-trihydroxy-6, 8-dimethoxyflavone (21), shihulimonin A (22), 6, 2'-dihydroxy-5, 7, 8, 6'-tetramethoxyflavone (26), viscidulin II (28), 5, 7, 4'-trihydroxy-8-methoxyflavone (29), 5, 7, 2', 6'-tetrahydroxyflavone (30), wogonin-7-O-beta-D-glucuronide methyl ester (31) and daucosterol (34).. On the basis of reported results of the chemical constituents of Rhizoma Coptidis, Radix Scutellariae, Cortex Phellodendri and Fructus Gardeniae, it was estimated that all flavonoid compounds rised from the Radix Scutellariae, and compounds 8 and 22 rised from Cortex Phellodendri. Compound 22 was identified in the Cortex Phellodendri for the first time. Topics: Acetates; Drugs, Chinese Herbal; Flavanones; Flavones; Flavonoids; Limonins; Magnetic Resonance Spectroscopy; Sitosterols; Spectrometry, Mass, Electrospray Ionization; Triterpenes; Ursolic Acid | 2008 |
Pharmacokinetics of baicalein, baicalin and wogonin after oral administration of a standardized extract of Scutellaria baicalensis, PF-2405 in rats.
The pharmacokinetics of active components such as baicalein, wogonin and oroxylin A were evaluated after oral administration of a purified extract of Scutellaria baicalensis GEORGI (PF-2405) containing the high contents of baicalein, wogonin and oroxylin A to rats. Following oral administration of PF-2405 at 10, 20 and 40 mg/kg dose (equivalent to 4.5, 9.0 and 18 mg/kg baicalein), a major constituent baicalein and its active metabolite baicalin showed dose-linear pharmacokinetics as evidenced by unaltered dose-normalized AUC, dose-normalized Cmax, Ae(0-30h) and GI(30h) values. Following oral administration of PF-2405 at three doses (equivalent to 0.4, 0.8 and 1.6 mg/kg wogonin), dose-normalized Cmax and dose-normalized AUC were comparable between the 20 and 40 mg/kg PF2405 doses, but plasma concentrations of wogonin at 10 mg/kg of PF-2405 were not measurable as they were below limit of quantitation (LOQ; 18 pmol/mL). Following oral administration of PF-2405 at the three doses (equivalent to 1.5, 3.0 and 6.0 mg/kg oroxylin A), the concentrations of oroxylin A in plasma, urine and gastrointestine samples were below the assay LOQ (18 pmol/mL). Significant differences in AUCs, Ae(0-30h) and GI(30h) values for baicalein and baicalin were observed after oral administration of pure baicalein (18 mg/kg) and PF-2405 (40 mg/kg). The increases in AUCs of baicalein and baicalin after oral administration of PF-2405 may have been due to the significant decrease in GO(30h) values for baicalein. Topics: Administration, Oral; Animals; Chromatography, Liquid; Flavanones; Flavonoids; Gastrointestinal Tract; Male; Plant Extracts; Rats; Rats, Sprague-Dawley; Scutellaria baicalensis; Tandem Mass Spectrometry | 2007 |
Liquid chromatography with tandem mass spectrometry for the simultaneous determination of baicalein, baicalin, oroxylin A and wogonin in rat plasma.
A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of baicalein, baicalin, oroxylin A and wogonin, Scutellaria baicalensis active components in rat plasma was developed. After liquid-liquid extraction with 2-(3,4-dimethoxy-phenyl)-5,7-dihydroxy-chromen-4-one as internal standard, baicalein, baicalin, oroxylin A and wogonin were eluted from an Atlantis C(18) column within 7 min with isocratic mobile phase consisting of methanol and 0.1% formic acid (60:40, v/v). The analytes were detected using an electrospray ionization tandem mass spectrometry in the multiple reaction monitoring (MRM) mode. The standard curves were linear (r=1.000) over the concentration ranges of 5-500 ng/ml for baicalein, wogonin and oroxylin A and 5-5000 ng/ml for baicalin. The coefficients of variation and relative errors of baicalein, wogonin, oroxylin A and baicalin for intra- and inter-assay at three or four quality control (QC) levels were 0.8-6.1% and -4.0 to 5.8%, respectively. The lower limits of quantification for baicalein, wogonin, oroxylin A and baicalin were 5ng/ml using 50 microl of plasma sample. This method was successfully applied to the pharmacokinetic study of baicalein, baicalin, wogonin and oroxylin A after an intravenous administration of Scutellariae radix extract to male Sprague-Dawley rats. Topics: Animals; Chromatography, Liquid; Flavanones; Flavonoids; Male; Plant Extracts; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Scutellaria; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry | 2006 |
Antioxidative and anti-inflammatory activities of polyhydroxyflavonoids of Scutellaria baicalensis GEORGI.
The active ingredients of 'golden root' of Scutellaria baicalensis GEORGI (Huang-Qin), a valuable traditional Chinese medicine, are polyhydroxyflavonoids, namely baicalein, oroxylin A and wogonin. With the objective of overcoming their poor solubility and to investigate their structure and activity relationships, baicaleinyl 7-O-sulfate was prepared, and extensive comparative antioxidative and anti-inflammatory tests were conducted. All the polyhydroxyflavonoids exhibited significant antioxidative and free-radical scavenging activities. In respect of their nitric oxide (NO) inhibition, wogonin was superior to all the other flavonoids, while oroxylin A was most potent in the inhibition of lipid peroxidation. Wogonin proved to be the most potent (82.9% inhibition, p<0.05) in its anti-inflammatory activity against carrageenan-induced rat hind paw edema. There was a correlation between the in-vivo anti-inflammatory activity and the in-vitro antioxidative activities. Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Drugs, Chinese Herbal; Edema; Flavanones; Flavonoids; Free Radical Scavengers; Lipid Peroxidation; Nitric Oxide; Phytotherapy; Rats; Scutellaria baicalensis; Solubility; Structure-Activity Relationship | 2006 |
Isolation and purification of baicalein, wogonin and oroxylin A from the medicinal plant Scutellaria baicalensis by high-speed counter-current chromatography.
The medicinal plant Scutellaria baicalensis Georgi has been used widely in traditional Chinese medicine for anti-inflammation, anticancer, antiviral and antibacterial infections, reducing the total cholesterol level and decreasing blood pressures. A high-speed counter-current chromatography (HSCCC) method was developed for the preparative separation and purification of three bioactive flavonoids, namely, baicalein, wogonin and oroxylin A, from S. baicalensis Georgi. Preparative HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-n-butanol-water (1:1:8:10, v/v/v/v) was successfully performed by increasing the flow-rate of the mobile phase stepwise from 1.0 to 2.0 ml min(-1) after 4 h. The components purified and collected were analyzed by high-performance liquid chromatography. The method yielded 144.8 mg of baicalein at 95.7% purity, 50.2 mg of wogonin at 98.5% purity, and 12.4 mg of oroxylin A at 93.2% purity from 500 mg of the crude extract in a one-step separation. The recoveries of baicalein, wogonin and oroxylin A were 92.7%, 91.6% and 92.5%, respectively. Topics: Chromatography, High Pressure Liquid; Countercurrent Distribution; Flavanones; Flavonoids; Scutellaria baicalensis | 2005 |
Analysis of inhibitory effects of scutellariae radix and baicalein on prostaglandin E2 production in rat C6 glioma cells.
Inhibitory mechanism of the water extract of Scutellariae Radix on prostaglandin E2 (PGE2) release was examined in C6 rat glioma cells. Scutellariae Radix reduced a Ca2+ ionophore A23187-induced PGE2 release by inhibition of arachidonic acid (AA) liberation. Sho-saiko-to and San'o-shashin-to, which contain Scutellariae Radix, also inhibited PGE2 release. A23187 caused phosphorylation of mitrogen-activated protein kinase (MAPK), resulting in activation of cytosolic phospholipase A2 (cPLA2). Scutellariae Radix and baicalein inhibited the phosphorylation of MAPK. Baicalein, but not baicalin, inhibited A23187-induced PGE2 release. These results suggest that baicalein in Scutellariae Radix reduces AA liberation through the inhibition of the MAPK-cPLA2 pathway. Topics: Amino Acid Sequence; Animals; Antineoplastic Agents; Arachidonic Acid; Calcimycin; Calcium-Calmodulin-Dependent Protein Kinases; Dinoprostone; Drugs, Chinese Herbal; Enzyme Inhibitors; Flavanones; Flavonoids; Glioma; Ionophores; Molecular Sequence Data; Phosphorylation; Prostaglandin Antagonists; Rats; Tumor Cells, Cultured | 1998 |
Inhibition of NAD(P)H:quinone acceptor oxidoreductase by flavones: a structure-activity study.
A structure-activity study was carried out to determine the important regions of baicalein and oroxylin A, two flavones isolated from the Chinese herb Scutellariae radix, in inhibiting NAD(P)H:quinone acceptor oxidoreductase (EC 1.6.99.2; DT-diaphorase). This quinone reductase is a vitamin K reductase. It is a target for and has been used as a model enzyme to investigate the mode of action of oral anticoagulants. The two flavones were found to inhibit this quinone reductase in nanomolar ranges. The 5-hydroxyl, 7-hydroxyl, 8-hydroxyl, and 2-phenyl groups of these flavones were found to be important for their inhibition of the enzyme. The inhibition profiles of the flavones on the NADH-menadione reductase activity, the NADH-potassium ferricyanide reductase activity, and the NADH-methyl red reductase activity of this enzyme were different. Therefore, even though the flavones were found to be competitive inhibitors with respect to NADH, they probably did not inhibit the enzyme by binding to the nicotinamide nucleotide binding site. Inhibition kinetic studies which indicated that these compounds bound to different sites than those for dicoumarol and phenindone were performed. These results indicate that these flavones are a new type of inhibitor of NAD(P)H:quinone acceptor oxidoreductase and potentially useful as anticoagulant drugs. Topics: Azo Compounds; Binding Sites; Binding, Competitive; Escherichia coli; Ferricyanides; Flavanones; Flavin-Adenine Dinucleotide; Flavonoids; Magnoliopsida; NAD; NAD(P)H Dehydrogenase (Quinone); NADP; Spectrophotometry; Structure-Activity Relationship; Vitamin K | 1993 |