Separation methods used for Scutellaria baicalensis active components

Scutellaria baicalensis Georgi is one of the most widely used traditional Chinese herbal medicines. Its roots have been used for anti-inflammation, anticancer, antiviral and antibacterial infections of the respiratory and the gastrointestinal tract, cleaning away heat, moistening aridity, purging fire, detoxifying toxicosis, reducing the total cholesterol level and decreasing blood pressures. Baicalin, baicalein, wogonin and oroxylin A are its main active components. This review provides an overview of various separation, detection, and identification techniques employed for the quantitative and qualitative determination of these active components. Applications of high-performance liquid chromatography, high-speed counter-current chromatography, thin layer chromatography, capillary electrophoresis, and micellar electrokinetic capillary chromatography to the separation and determination of these active components are described. Examples of identification of these active components and their metabolites in complex matrices by high-performance liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry are also presented. The advantages and limitations of these separation and identification methods are assessed and discussed.

A metabolomic analysis of medicinal diversity in Huang-qin (Scutellaria baicalensis Georgi) genotypes: discovery of novel compounds

In vitro manipulation of plant regeneration in the Chinese medicinal species Scutellaria baicalensis Georgi (Huang-qin) resulted in 26 chemically distinct germplasm lines. Antioxidant potential, growth rate and concentration of baicalin, baicalein, melatonin, and wogonin were the selective markers used to identify elite lines. Metabolomic analysis of a subset of the most distinct lines revealed that Huang-qin extracts contained over 2,000 compounds including 781 determined to be of putative medicinal importance as determined by a database search, as well as previously unidentified amino-derivatives of baicalin and wogonin. Huang-qin also contained a metabolite with the same net formula as hyperforin, previously thought to be unique to Hypericum perforatum L. Together these results provide new insights into the biochemical complexity of an important medicinal species and demonstrate the power of in vitro manipulation in combination with untargeted metabolomic screening for the production of new germplasm.

Influence of bioflavonoids from the radix extract of Scutellaria baicalensis on the level of serum lipids, and the development of laboratory rats fed with fresh and oxidized fats

The aim of this study was to assess the influence of bioflavonoids from the radix of Scurellaria baicalensis on the level of lipids, via the determination of the concentrations of triglycerides, total cholesterol and high-density lipoprotein (HDL) cholesterol in the plasma of laboratory rats fed high-fat and high-cholesterol diets, and via the calculation of their atherogenic index. We also studied the influence of bioflavonoids on their physical development by measuring the increase in their body mass and liver mass. The rats were fed a diet with a 15% content of fresh or oxidized lard or sunflower oil, along with 0.5% added cholesterol. 0.05% S. baicalensis radix extract was added to the diet of half of the rats as the source of bioflavonoids. In the group of rats fed a diet containing oxidized oil we observed a significantly lower increase in body mass (15.5 +/- 7.6 g/4 weeks/rat) than that observed for the control rats (77.0 +/- 15.7 g/4 weeks/rat). The addition of S. baicalensis radix extract to the diet raised the increase in body mass in the groups receiving oil as the source of fat; those receiving fresh oil had a 40% increase, and those receiving oxidized oil showed a 300% increase relative to the appropriate controls. In all the groups of rats fed a diet with bioflavonoids added, a beneficial decrease in the plasma triglyceride content was observed relative to the appropriate controls. In the plasma of rats on a diet containing the extract and fresh or oxidized oil or fresh lard, we observed a beneficial reduction in the total cholesterol level relative to the appropriate controls. The atherogenic index was higher for the group of animals fed with fresh lard than for those fed with fresh oil, and higher for those fed with oxidized oil than for those fed with oxidized lard. The addition of bioflavonoids to the diet beneficially reduced the atherogenic index value in the group fed with fresh oil, and increased its value in the group fed with oxidized lard.

Antimutagenic and antiradical properties of flavones from the roots of Scutellaria baicalensis georgi

The four flavonoids baicalin, baicalein, wogonoside, and wogonin have been isolated from Scutellaria baicalensis (Lamiaceae) root extract as main bioactive components. We evaluated their antimutagenic activity as potential chemopreventive natural substances using the Ames test. Free radical scavenging properties have also been measured with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Both crude extract and isolated flavone glycosides and aglycones have antimutagenic and free radical scavenging properties. The lipophilic flavone baicalein has been confirmed to be the most powerful antimutagen among the compounds tested.

[Inhibitory effect and its kinetic analysis of baicalein on recombinant human protein kinase CK2 holoenzyme]

BACKGROUND & OBJECTIVE

Protein kinase CK2 is a ubiquitous and pleiotropic Ser/Thr protein kinase in eukaryotic cells. CK2 activity has been shown to be markedly elevated in solid tumors and leukemia cells. Its alpha or alpha' gene is a protooncogene. CK2 is attracting increasing attention as a potential target for anti-neoplastic. This study was to search specific CK2 inhibitors in tumor cells through observation of the inhibitory effects of baicalein on recombinant human protein kinase CK2 holoenzyme and its kinetics in vitro.

METHODS

Recombinant human protein kinase CK2 alpha' and beta subunits were cloned and expressed by gene engineering, and purified to homogeneous. These 2 subunits were mixed at equal molar ratio to reconstitute CK2 holoenzyme. The CK2 activity was evaluated by detecting radioactivity of 32P of [gamma-32P]ATP which was incorporated into the substrate in various conditions.

RESULTS

Baicalein was shown to strongly inhibit the holoenzyme activity of CK2 with IC50 of 2.54 micromol/L. Kinetic studies of baicalein on CK2 showed that baicalein acted as an inhibitor of noncompetitive with ATP(KI=7.73 micromol/L) and mixed types with casein(KI=3.07 micromol/L).

CONCLUSION

Baicalein is an effective inhibitor of protein kinase CK2 in vitro.

Quality Evaluation of Commercial Extracts of Scutellaria baicalensis

Botanical products have been widely used for various illnesses and general well-being. However, quality control of botanical products is often not performed due to lack of standardization, resulting in inconsistent efficacies and sometimes serious toxicity. The goals of this study were to determine the correlation between chemical composition and biological activities and to establish a method to measure authenticity, chemical consistency, and biological potency of botanical products. A high-performance liquid chromatography method was used to analyze the authenticity and chemical composition of 10 different commercial extracts. The cell viability assay and prostaglandin E2 (PGE2) enzyme immunoassay were used to analyze biological potency and consistency. Our results showed all extracts contained marker components (baicalein and/or baicalin), confirming their authenticity. However, significant product-to-product and batch-to-batch variation of these marker components was observed with 4 products containing no baicalin at all and baicalein concentration ranging from 0 to 52.3 g/mg. The 50% growth inhibition concentration of the extracts ranged from 0.18 to 2.0 mg/ml, more than an 11-fold variation. PGE2 levels varied from 19.5 to 111.1 pg/106 cells, more than a 5.7-fold difference. These results demonstrated significant variation in chemical composition and biological activities of the commercial extracts and that the amount of marker components may not reflect biological activity levels. Therefore, chemical analysis alone is inadequate for quality control, and biological assays must be included for botanical products to ensure chemical authenticity as well as pharmacological/biological potency and consistency.

[Experimental study on anti-pyretic effect of gegen qin lian decoction and its compounds]

OBJECTIVE

To investigate composition principles of Gegen Qin Lian decoction through anti-pyretic experiment.

METHOD

Pharmacological effects of different compounds of Gegen Qin Lian decoction according to six hours temperature response index (TRI6) and average top temperature response height (deltaT) after the decoction was given to feverish animal model by inactived bacteria suspension.

RESULT

As for reducing six hour temperature response index, Scutellaria baicalensis root was the main effective drug. Pueraria lobata root could enforce the effect while Coptis chinensis rhizome and Glycyrrhiza uralensis root counteracted it. As for reducing average top temperature response height, the Effects of four herbal drugs were the same as for TRI6.

CONCLUSION

Of the compounds of Gegen Qin Lian decoction, as to the pharmcological anti-pyretic effects, the best one is the compound of Scutellaria baicalensis and Pueraria lobata roots.

Potent Inhibitory effect of flavonoids in Scutellaria baicalensis on amyloid beta protein-induced neurotoxicity

The free radical scavenging activities of two major flavonoids (baicalein and baicalin) in Scutellaria baicalensis were determined. The antioxidant capacities of baicalein and baicalin were determined by the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(*)(-) scavenging assay and showed about 110 and 70% vitamin C equivalent antioxidant capacity, respectively. Because amyloid beta (Abeta) protein is known to increase free radical production and lipid peroxidation in PC12 nerve cells, leading to apoptosis and cell death, treatment with baicalein and baicalin may result in the prevention of cellular damage by the Abeta-induced reactive oxygen species. We found that baicalein and baicalin resulted in a dose-dependent anti-Abeta toxicity by means of three different assays [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction, lactate dehydrogenase release, and trypan blue exclusion assays]. These results suggest that baicalein as well as baicalin can reduce the cytotoxicity of Abeta protein in PC12 cells, possibly by a reduction of oxidative stress, and these flavonoids may be useful in the chemoprevention of Alzheimer's disease.

Application of high-speed counter-current chromatography to the preparative separation and purification of baicalin from the Chinese medicinal plant Scutellaria baicalensis

Baicalin was separated and purified for the first time from the traditional Chinese medicinal plant Scutellaria baicalensis Georgi by high-speed counter-current chromatography. Crude baicalin was obtained by extraction with methanol-water (70:30, v/v) from S. baicalensis Georgi. The separation was performed in two steps with a two-phase solvent system composed of n-butanol-water (1:1, v/v), in which the lower phase was used as the mobile phase at a flow-rate of 1.0 ml min(-1) in the head-to-tail elution mode. A total of 37.0 mg of baicalin at 96.5% purity was yielded from 200 mg of the crude baicalin (containing 21.6% baicalin) with 86.0% recovery as determined by HPLC analysis.

Hepatoprotective effect of baicalin, a major flavone from Scutellaria radix, on acetaminophen-induced liver injury in mice

The protective effects of baicalin (BA), a major flavone from Scutellaria radix, on acetaminophen (AP)-induced hepatotoxicity and the possible mechanism(s) of its protective action were investigated in mice. Treatment with BA (300 mg/kg, p.o.) 0.5 h after AP administration significantly prevented an increase in plasma alanine aminotransferase and aspartate aminotransferase activities and AP-induced hepatic necrosis, and also reduced AP-induced mortality from 43% to 0%. In addition, oral treatment with BA significantly prevented AP-induced depletion of glutathione (GSH) contents. However, BA treatment, by itself, did not affect hepatic GSH contents. The effect of BA on the cytochrome P450 2E1 (CYP2E1), the major isozyme involved in AP bioactivation, was investigated. Oral treatment of mice with BA resulted in a significant decrease in AP-induced CYP2E1 activity together with its inhibition of AP-induced CYP2EI expression. These results show that the hepatoprotective effects of BA against AP overdose may be due to its ability to block the bioactivation of AP by inhibiting CYP2E1 expression.

Proteomic analysis of mouse liver for the evaluation of effects of Scutellariae radix by liquid chromatography with tandem mass spectrometry

Scutellariae radix or Scutellaria baicalensis is a medicinal plant that contains major flavonoids such as baicalein, baicalin, wogonin and wogonosides. The present work describes the development of an approach using proteomic analysis of mouse liver to study the effects of prolonged exposure to substances present in chemically standardized Scutellariae radix extracts. Histopathological examination of the mouse liver was compared with the proteome data. The botanical extracts were prepared using pressurized liquid extraction (PLE). A method without isotope labeling was developed, using proteolytic digestion with one- and two-dimensional liquid chromatography with tandem mass spectrometry, and was used to characterize the extent of differential protein expression in mouse liver in response to external factors such as extracts from Scutellariae radix. From the histopathological examination and proteome data, significant changes in the mouse livers were not observed for the low-dose group. The Scutellariae radix extracts at high dose were observed to cause damage at the bile duct and expression change of a number of proteins including some involved in catabolism of triglyceride-rich particles, carbohydrate metabolism, regulators of cell signaling processes, and enzymes involved in biotransformation. Thus, proteomic analysis of liver samples from mice treated with botanical extracts is a promising approach to provide information on any potential toxicity effects of the extracts. The present method also provides another means for comparing proteomes in biological samples such as liver lysates from mice subjected to different treatments.

[Study on subcritical water extraction of baicalin from Radix Scutellariae coupled to high performance liquid chromatographic analysis]

A method for the extraction of baicalin from Radix Scutellariae with subcritical water coupled to high performance liquid chromatographic analysis was established. The effects of various parameters, which included the pressure, temperature, extraction time, and the particle size of the plant material as well as the solvent/sample ratio on the yield were investigated. Compared to the conventional organic solvent extraction method, the subcritical water extraction method showed shorter handling time and lower solvent consumption without waste producing. The optimal conditions of extraction of baicalin from Radix Scutellariae with subcritical water were 0.15 - 0.18 mm particle size, solvent/sample ratio of 0.2 mL/mg, 5 MPa, 130 degrees C for about 10 min. This technique seems very promising for the extraction of liposoluble substances from plant materials.

Baicalin induces differential expression of cytochrome C oxidase in human lung H441 cell

In a previous study, we evaluated the effect of baicalin on the expression of SP-A (surfactant protein A), which was developmentally regulated in an alveolar type II cell, H441. SP-A is encoded by two similar genes, SP-A1 and SP-A2, in humans. The maximal induction of SP-A1 gene of H441 occurred at treating 150 nM of baicalin for 48 h. In the present study, cDNA subtraction analysis is performed to examine the differential expression in H441 cell upon baicalin treatment with a view to investigating the regulatory mechanism. The mRNA of H441 cell incubated with 150 nM baicalin for 48 h was compared to that of blank control. Two PCR products were obtained through subtractive cDNA amplification. A product encoding cytochrome c oxidase was demonstrated to be a differential signal by RT-PCR analysis, and the other was a false positive. The induction of cytochrome c oxidase might increase ATP level in cell, and consequently elevates cAMP, which upregulates surfactant synthesis and secretion.

Scutellaria baicalensis extract decreases cisplatin-induced pica in rats

PURPOSE

Nausea/vomiting are significant side effects associated with the use of chemotherapy in cancer patients. Treatment of nausea/vomiting caused by cisplatin, a potent chemotherapeutic agent and one of the most emetogenic stimuli, requires a combination of different antiemetic drugs. In this study, we investigated the effects of Scutellaria baicalensis, an antioxidant herbal medicine, on cisplatin-induced nausea using a rat model.

METHODS

Rats react to emetic/nausea-producing stimuli, such as cisplatin, with altered feeding habits, manifested by pica or increased consumption of kaolin (a type of clay). We measured pica in rats to quantify cisplatin-induced nausea, and to evaluate the antinausea effect of pretreatment with S. baicalensis extract (SbE) given intraperitoneally.

RESULTS

Cisplatin at 3 mg/kg induced significant pica accompanied by reduced food intake, suggesting the presence of nausea. Hence, this cisplatin dose was selected for testing the antinausea activity of SbE. Cisplatin-induced pica decreased significantly when animals were pretreated with SbE at doses of 1 mg/kg and 3 mg/kg ( P<0.01). At a higher SbE dose (10 mg/kg), kaolin consumption increased, rather than further decreased, and was significantly different from that in the groups treated with low SbE doses.

CONCLUSIONS

SbE pretreatment decreased cisplatin-induced kaolin intake in the rat model of simulated nausea, suggesting that SbE and its active constituent(s) may play a therapeutic role in chemotherapy-induced emesis. Absence of therapeutic effect at the highest tested SbE dose could have been a result of prooxidant activity often associated with excess antioxidant concentration.

Effects of wogonin, a plant flavone from Scutellaria radix, on skin inflammation: in vivo regulation of inflammation-associated gene expression

Flavonoids from plant origin show anti-inflammatory activity in vitro and in vivo. In addition to inhibition of inflammation-associated enzymes, such as cyclooxygenases (COX) and lipoxygenases, they have been found to regulate the expression of inflammation-associated proteins from in vitro experiments. In order to prove in vivo behavior and the potential for beneficial use against inflammatory skin disorders, the effect of wogonin (5,7-dihydroxy-8-methoxyflavone) on in vivo expression of several inflammation-associated genes was examined in the intact as well as in the inflamed mouse skin by reverse transcriptase-polymerase chain reaction analysis. When applied topically on the intact skin, only a high dose treatment of wogonin (1000 microg/ear/3 days) slightly increased COX-1 and fibronectin mRNA. On the other hand, wogonin at the doses of 250-1000 microg/ear/3 days potently lowered mRNA levels of COX-2 and tumor necrosis factor-alpha with less effect on intercellular adhesion molecule-1 and interleukin-1beta in a sub-chronic skin inflammation model of tetradecanoylphorbol-13-acetate-induced ear edema (multiple treatment). The decrease of prostaglandin E(2) concentration (27.3-34.3%) was concomitantly observed in the wogonin-treated groups. A similar effect was also observed in an acute inflammation model of arachidonic acid-induced ear edema. From the present study, wogonin was proved to differentially regulate the expression of inflammation-associated genes in vivo and to become a useful therapeutic agent for skin inflammatory diseases mainly due to its modulation of the expression of proinflammatory molecules.

Differential effects of natural polyphenols on neuronal survival in primary cultured central neurons against glutamate- and glucose deprivation-induced neuronal death

Neuronal injury in the central nervous system following ischemic insult is believed to result from glutamate toxicity and glucose deprivation. In this study, polyphenols isolated from Scutellaria baicalensis Georgi, including baicalin, baicalein, and wogonin, were investigated for their neuroprotective effects against glutamate/NMDA (Glu/NMDA) stimulation and glucose deprivation in primary cultured rat brain neurons. Cell death was accessed by lactate dehydrogenase (LDH) release assay for necrosis, and mitochondrial activity was accessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction activity assay. It was found that both baicalin and baicalein decreased LDH release of the cultured neurons after 24 h treatment, whereas wogonin profoundly increased LDH release after 2 h treatment and resulted in neuronal death after 24 h. Glu/NMDA treatment profoundly increased LDH release and moderately decreased MTT reduction activity in an NMDA receptor-dependent manner. Both baicalin and baicalein significantly reduced Glu/NMDA-increased LDH release, in which baicalein is much more potent than baicalin. Glu/NMDA-increased intracellular calcium was also significantly attenuated by baicalin and baicalein. Baicalin and baicalein did not affect glutamate receptor binding activity, but baicalein did moderately decrease Glu/NMDA-induced nitric oxide (NO) production. In the glucose deprivation (GD) study, baicalein but not baicalin showed significant protective effects on the GD-increased LDH release, without affecting the GD-induced NO production, in cultured rat brain neurons. These results suggest that baicalein is the most effective compound among three polyphenols tested in preventing neurotoxicity induced by both glutamate and GD, whereas baicalin was only effective in preventing glutamate toxicity. Wogonin might have a neurotoxic effect on the brain.

Inhibition of cancer cell proliferation and prostaglandin E2 synthesis by Scutellaria baicalensis

Scutellaria baicalensis is a widely used Chinese herbal medicine that has been used historically in anti-inflammatory and anticancer therapy. The purpose of this study is to verify its anticancer activity on head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo and to investigate its effect on cyclooxygenase-2 (COX-2), which converts arachidonic acid to prostaglandin E(2) (PGE(2)) and is highly expressed in HNSCC. Two human HNSCC cell lines (SCC-25 and KB) and a nontumorigenic cell line (HaCaT) were tested in vitro for growth inhibition, proliferation cell nuclear antigen expression, and COX-2 activity and expression after treatment with Scutellaria baicalensis extract. Its effects were compared with those of baicalein (a flavonoid isolated from Scutellaria baicalensis), indomethacin (a nonselective COX inhibitor), and celecoxib (a selective COX-2 inhibitor). Four nude mice with s.c. inoculation of KB cells were tested for its anticancer activity in vivo by oral administration of Scutellaria baicalensis at a dose of 1.5 mg/mouse (75 mg/kg), five times/week for 7 weeks. Scutellaria baicalensis and other agents demonstrated a strong growth inhibition in both tested human HNSCC cell lines. No growth inhibition of HaCaT cells was observed with Scutellaria baicalensis. The IC(50)s were 150 micro g/ml for Scutellaria baicalensis, 25 micro M for celecoxib, and 75 micro M for baicalein and indomethacin. Scutellaria baicalensis, as well as celecoxib and indomethacin, but not baicalein, suppressed proliferation cell nuclear antigen expression and PGE(2) synthesis in both cell types. Scutellaria baicalensis inhibited COX-2 expression, whereas celecoxib inhibited COX-2 activity directly. A 66% reduction in tumor mass was observed in the nude mice. Scutellaria baicalensis selectively and effectively inhibits cancer cell growth in vitro and in vivo and can be an effective chemotherapeutic agent for HNSCC. Inhibition of PGE(2) synthesis via suppression of COX-2 expression may be responsible for its anticancer activity. Differences in biological effects of Scutellaria baicalensis compared with baicalein suggest the synergistic effects among components in Scutellaria baicalensis.

5,7-Dihydroxy-6-methoxyflavone, a benzodiazepine site ligand isolated from Scutellaria baicalensis Georgi, with selective antagonistic properties

As part of an effort to identify naturally occurring GABA(A) receptor benzodiazepine binding site (BDS) ligands from traditional medicinal herbs, we previously reported that flavonoid derivatives isolated from Scutellaria baicalensis (S. baicalensis) Georgi exhibited significant affinities for the BDS. The present study describes the characterization of 5,7-dihydroxy-6-methoxyflavone (oroxylin A), one of the major components of the herbal extract. Oroxylin A inhibited [3H]flunitrazepam binding to rat cerebral cortical membrane with a IC(50) value of 1.09+/-0.07 microM. A GABA ratio of 1.09+/-0.04 suggests that oroxylin A interacts as an antagonist at the recognition site. In neuropharmacological studies, oral administration of oroxylin A (3.75-60 mg kg(-1)) did not result in significant changes in animal models routinely employed for benzodiazepine (BD) evaluation. However, oroxylin A selectively abolished the anxiolytic, myorelaxant and motor incoordination, but not the sedative and anticonvulsant effects elicited by diazepam, a BDS agonist. These results add oroxylin A to the list of CNS active flavonoids, and as the first naturally occurring member endowed with selective antagonistic actions via the BDS.

[Effect of Radix scutellariae on the growth and form of Porphyromanus endodontics in vitro]

OBJECTIVE

To provide scientific evidence for underpinning the use of Radix Scutellariae in the treatment of pulp and periapical diseases.

METHODS

Using minute amount serial dilution test, this study assessed the minimal inhibitory concentration of Radix Scutellariae extreact against Porphyromanus Endodontics. The forms of Porphyromanus endodontics treated with Radix Scutellariae extract at different concentrations were observed by use of SEM.

RESULTS

The MIC of Radix Scutellariae extract was determined to be 1 mg/ml. Radix Scutellariae changed the forms of Porphyromanus endodontics, making them become bigger, longer and crumbled.

CONCLUSION

Radix Scutellariae could inhibit the growth of Porphyromanus Endodontics.

[Screening 20 Chinese herbs often used for clearing heat and dissipating toxin with nude mice model of hepatitis C viral infection]

OBJECTIVE

To seek effective drugs for anti-hepatitis C virus by screening 20 Chinese herbs often used for clearing heat and dissipating toxin with nude mice model of hepatitis C viral (HCV) infection.

METHODS

After the model mice had been treated with selected drug for 3 months, transmission electron microscope was used to observe whether the HCV-like particles in human fetal hepatocytes (HFH) transplanted into mice spleen still existed, and quantitative RT-PRC technique was used to detect the serum content of HCV-RNA before and after treatment.

RESULTS

(1)HCV-like particles existed in all the model mice after treatment. (2) Serum content of HCV-RNA decreased after treated with Radix Gentianae, Radix Scutellariae, Radix Sophorae tonkinensis, Fructus Gardeniae and Fructus Sophorae flavoscentis, but unchanged after treatment with other drugs.

CONCLUSION

All the 20 herbs screened has not effect in directly eradicating HCV, but Radix Gentianae, Radix Scutellariae, Radix Sophorae tonkinensis, Fructus Gardeniae and Fructus Sophorae flavoscentis could significantly inhibit the replication of HCV-RNA.

[The study of characteristics of absorption and separation of different glycoside on macropore resins]

OBJECTIVE

To study the absorption and separation of different glycoside on different macropore resins.

METHOD

Take baikal skullcap root, cape jasmine fruit and white peony root as samples and study the different characterstics of absorption and separation of these samples on macropore resins such as D101 and so on.

RESULT

The static absorption effect of the the three aglycones on six different macropore resins is baicalin > lactiflorin > gardoside. Their elution are 75% CH3OH, 25% CH3OH, and 45% CH3OH. Their elution rates are 60%, 93%, and 93%.

CONCLUSION

Similar molecules may not have similar absorption abilities on same macropore resins, but the effect of absorption has something to do with the structures of the molecules, the more double-bonds the molecules have, the greater the absorption force the resins have.

Effects of wogonin, wogonoside, and 3,5,7,2',6'-pentahydroxyflavone on chemical mediator production in peritoneal exduate cells and immunoglobulin E of rat mesenteric lymph node lymphocytes

Wogonin (WG), wogonoside (WGS), and 3,5,7,2',6'-pentahydroxyl flavanone (PHF) were isolated from Scutellaria baicalensis, and their effects on histamine, leukotriene B(4) (LTB(4)), and immunoglobulin E (IgE) were examined in rats, observing for a manifestation of a type I allergic reaction. WG and WGS in the amounts of 10 and 100 microM were shown to markedly inhibit histamine release in cells stimulated with calcium ionophore A23187 or compound 48/80. PHF exerted inhibitory activity only at 100 microM. In the case of LTB(4), WG, WGS and PHF markedly inhibited LTB(4) production at the concentration of 100 microM. We also find that the increase in the IgE content induced by concanavalin A (ConA) was alleviated in the presence WG and WGS, while the inhibitory effect of PHF was much weaker. However, the magnitude of inhibitory effect observed on the content of lipid peroxidation induced by ConA was in order of PHF > WG > WGS, with PHF being the strongest. Interestingly, WG and WGS with the methoxyl group strongly inhibited histamine and IgE production, whereas PHF with the hydroxyl group in the B ring was much stronger than WG and WGS against lipid peroxidation. Based on data, it was concluded that the flavonoid components, WG, WGS, and PHF, may block a common pathway for the release of histamine and LTB(4), and that the IgE level is responsible for the lipid peroxidation induced by ConA.

[Recognition of three classes of skullcaps by FTIR spectroscopy combined with artificial neural networks]

In order to recognition of three classes of skullcaps (cultivated, wild Scutellaria baicalensis Georgi and Scutellaria viscidula Bge) three kinds of models of artificial neural networks (ANN), nonlinear-linear, linear-linear and nonlinear-nonlinear model, were used combined with their infrared spectra. Skullcaps samples were collected by Fourier Transform Infrared (FTIR) spectra. 42 samples were gathered as a train set, and 34 samples as a test set, then their supervision trains were performed using three models each. When the summation of error square of train target was selected as 0.01, the correct rate for recognition of three classes of skullcaps using each ANN was 100% for the train set, but was different for the test set, which depended on the number of node in hidden layer, S1. It was found that with the increase of S1, the correct rate would decrease oppositely. This may be caused by the high degree of the non-linearity of the networks, so that the models of networks were not fit for the train of this kind of sample set. When using linear-linear model of ANN varied with S1 in some extent, the correct rate was generally about 85%. Recognizability obtained using nonlinear-linear model of ANN was the best. Its correct rate of recognition was > 97% when S1 = 3, and so this method can be used to recognize three of skullcaps simply, rapidly, and accurately.

Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis Georgi

The search for novel anxiolytics devoid of undesirable side-effects typical of classical benzodiazepines (BDZs) has been intense, and flavonoids, as a relative new class of ligands, have been shown to possess anxiolytic effects in vivo. The present study evaluated the pharmacological properties of a naturally occurring monoflavonoid, 5,7-dihydroxy-8-methoxyflavone or wogonin. The affinity (K(i)) of wogonin for the benzodiazepine site (BZD-S) on the gamma-aminobutyric acid(A) (GABA(A)) receptor complex was 0.92 microM. Using electrophysiological techniques, we showed that wogonin enhanced the GABA-activated current in rat dorsal root ganglion neurons, and in Xenopus laevis oocytes expressing recombinant rat GABA(A) receptors, the enhancement was partially reversed by the co-application of a 1 microM concentration of the BZD-S antagonist anexate (Ro15-1788). Acute toxicity and behavioral effects were examined in mice. Acute lethal activity was low, with an LD(50) of 3.9 g/kg. Oral administration of wogonin (7.5 to 30 mg/kg) elicited an anxiolytic response that was similar to that elicited by diazepam in the elevated plus-maze; a dose-dependent increase in open arm entries and time spent in open arms was observed. More importantly, its anxiolytic effect was blocked by the co-administration of Ro15-1788. In the holeboard test, not only did wogonin-treated mice experience an increased number of head-dips but they also spent more time at it, showing no signs of sedation. Furthermore, wogonin did not cause myorelaxant effects in the horizontal wire test. Taken together, these data suggest that wogonin exerts its anxiolytic effect through positive allosteric modulation of the GABA(A) receptor complex via interaction at the BZD-S. Its anxiolytic effect was not accompanied by sedative and myorelaxant side-effects typical of BDZs.