Scutellaria Baicalensis Root Research Articles

Baicalein induces the apoptosis of U251 glioblastoma cell lines via the NF-kB-p65-mediated mechanism

ABSTRACTGlioblastoma (GBM) is the most aggressive cerebral gliomas. Moreover, the overall prognosis of GBM is still little. Baicalein (BA) is a flavonoid derived from the Scutellaria baicalensis root, and has historically been used in anticancer therapies. However, its apoptosis role and related mechanisms in GBM has not yet been researched clearly. Thus, this study aimed to investigate the effects of BA on human GBM U251 cell line. The effects of BA on proliferation of U251 cells were measured by Cell Counting Kit-8 assay. Cellular apoptosis was detected by flow cytometry with annexin V-FITC/propidium iodide staining. The expression of apoptosis-related protein Bcl-2, Bax and cleaved-caspase3 was detected by quantitative real-time PCR and western blot. The expression of nuclear p65 protein, the active subunit of nuclear factor-kappa B (NF-κB), was determined by immunofluorescence and western blot. Our results showed that the viability of U251 cells significantly decreased in a time- and dose-dependent manner after treated with BA, and the apoptotic ratio of BA-treated groups was significantly higher than that of control groups. Furthermore, the expression of NF-kB-p65 in the nucleus was remarkably reduced, and the activity of NF-kB-p65 was remarkably inhibited after BA treatment. Combined treatment with a NF-kB-P65 inhibitor (QNZ) and BA resulted in the synergistic reduction of Bcl-2 expression and then increase of Bax and cleaved-caspase3 expression; and the viability of U251 cells was also inhibited. In conclusion, BA inhibits GBM cells viability and induces apoptosis via inhibit the activity of NF-kB-p65, suggesting that BA is a potential therapeutic agent for GBM.

Application of a new method, orthogonal projection to latent structure (OPLS) combined with principal component analysis (PCA), to screening of prostaglandin E2 production inhibitory flavonoids in Scutellaria Root.

A new method consisting of orthogonal projection to latent structure (OPLS) and modified principal component analysis (PCA) was applied to a screening of bioactive compounds from natural products. In this report, extracts of 52 Scutellaria Root (the root ofScutellaria baicalensis Georgi) samples were analyzed by high-performance liquid chromatography (HPLC), and their inhibitory activities towards prostaglandin E2 (PGE2) production in a murine macrophage-like cell line J774.1 were examined. Wogonin and oroxylin A were predicted to be strong inhibitors of PGE2 production by OPLS analysis of the data. However, 6-methoxywogonin, which has been reported to have inhibitory activity, was omitted. Modified PCA was then applied to these data as a filter to exclude compounds less relevant to the activity, and OPLS analysis was applied to the modified data. As a result, this method predicted wogonin, oroxylin A and 6-methoxywogonin to be strong inhibitors of PGE2 production without any prior knowledge. The predictions by the OPLS combined with PCA method of PGE2 production inhibitory activities of 52 samples showed good agreement with the actual data. This method is simple and effective and can be used in screening of bioactive natural compounds without any prior knowledge.

Baicalin and Baicalein Inhibit Src Tyrosine Kinase and Production of IL-6

Flavonoids play an important role in the treatment of various diseases, as they are able to inhibit reactive oxygen species, which cause damage to cells and tissues which may lead to increased risk of inflammatory diseases. Baicalin and baicalein, two flavonoids found in the roots ofScutellaria baicalensis, in the leaves ofThymus vulgarisandOroxylum indicum, were tested for their anti-inflammatory activity as well as for their cytotoxicity. Thereby the two compounds were investigated on Src tyrosine kinase inhibition and inhibition of production of interleukin (IL-6) in lipopolysaccharide- (LPS-) stimulated THP-1 cells. Additionally, the THP-1 cell line was used for the determination of the cytotoxicity. Both baicalin and baicalein showed some anti-inflammatory properties, while baicalein turned out to be the more active compound with higher inhibitory activities on both Src tyrosine kinase and production of cytokine IL-6. Baicalin and baicalein showed no signs of cytotoxicity in the MTS cytotoxicity assay in THP-1 cells.

Antiobesity Effects of the Combined Plant Extracts Varying the Combination Ratio of Phyllostachys pubescens Leaf Extract and Scutellaria baicalensis Root Extract.

The antiobesity effects of several different combinations of extracts (BS) prepared from two plants, Phyllostachys pubescens leaf (bamboo leaf: BL) and Scutellaria baicalensis root (SB), were investigated using a high fat diet (HFD) induced obese mouse model. In order to find the most effective mixture among the mixtures of the two plant extracts, experimental preparations were made by combining BL and SB by different proportions of 3 : 1 (BS31), 2 : 1 (BS21), 1 : 1 (BS11), 1 : 2 (BS12), and 1 : 3 (BS13). Body weight, weight of adipose tissues, size of adipocytes, levels of glucose, leptin and adiponectin, and lipid profile in serum, and fat accumulation in liver were investigated. We have found that BS21 is the most effective in antiobesity among the five mixtures investigated, indicated by reduction in body weight gain, total mass of adipose tissue, and the size of adipocyte. In addition, BS21 has shown to be beneficial in serum lipid profile, levels of glucose, leptin, and adiponectin in serum, and fat accumulation in liver. By chromatographic separation of BS21, the two maker compounds, isoorientin and baicalin, were identified and quantified for the standardization of BS21.

Влияние синтетического антиоксиданта тиофана и экстракта трансформированных корней шлемника байкальского на индуцированный мутагенез

На модели повреждения генетических структур личинок Dr. melanogaster цисплатином и циклофосфаном изучены генопротекторные свойства синтетического антиоксидантного вещества тиофана и экстракта трансформированных корней шлемника байкальского (ЭШБ). При добавлении в питательную среду тиофана или ЭШБ отмечено снижение количества рекомбинантов Dr. melanogaster (самок, несущих рецессивные маркерные мутации yellow и/или singed).

Baicalein increases the expression and reciprocal interplay of RUNX3 and FOXO3a through crosstalk of AMPKα and MEK/ERK1/2 signaling pathways in human non-small cell lung cancer cells.

BackgroundBaicalein, a natural flavonoid obtained from the Scutellaria baicalensis root, has been reported to inhibit growth of human lung cancer. However, the detailed mechanism underlying this has not been well elucidated.MethodsCell viability was measured using a 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assays. Apoptosis was detected by flow cytometry analysis and caspase 3/7 assays. The expression of RUNX3 and FOXO3a mRNA were measured by real time RT-PCR methods. Western blot analysis was performed to measure the phosphorylation and protein expression of AMP-activated protein kinase alpha (AMPKα) and extracellular signal-regulated kinase 1/2 (ERK1/2), runt-related transcription factor 3 (RUNX3) and forkhead box O3a (FOXO3a). Silencing of FOXO3a and RUNX3 were performed by small interfering RNA (siRNA) methods. Exogenous expression of FOXO3a or RUNX3 was carried out by electroporated transfection assays.ResultsWe showed that baicalein significantly inhibited growth and induced apoptosis of non-small cell lung cancer (NSCLC) cells in a time- and dose-dependent manner. Baicalein induced RUNX3 and FOXO3a protein expression, and increased phosphorylation of AMPKα and ERK1/2. Moreover, the inhibitors of AMPK and MEK/ERK1/2 reversed the effect of baicalein on RUNX3 and FOXO3a protein expression. Interestingly, while compound C had little effect on blockade of baicalein-induced phosphorylation of ERK1/2, PD98059 significantly abrogated baicalein-induced phosphorylation of AMPKα. Intriguingly, while silencing of RUNX3 abolished the effect of baicalein on expression of FOXO3a and apoptosis, silencing of FOXO3a significantly attenuated baicalein-reduced cell proliferation. On the contrary, overexpression of FOXO3a restored the effect of baicalein on cell growth inhibition in cells silencing of endogenous FOXO3a gene and enhanced the effect of baicalein on RUNX3 protein expression. Finally, exogenous expression of RUNX3 increased FOXO3a protein and strengthened baicalein-induced phosphorylation of ERK1/2.ConclusionCollectively, our results show that baicalein inhibits growth and induces apoptosis of NSCLC cells through AMPKα- and MEK/ERK1/2-mediated increase and interaction of FOXO3a and RUNX3 protein. The crosstalk between AMPKα and MEK/ERK1/2 signaling pathways, and the reciprocal interplay of FOXO3a and RUNX3 converge on the overall response of baicalein. This study reveals a novel mechanism for regulating FOXO3a and RUNX3 signaling axis in response to baicalein and suggests a new strategy for NSCLC associated targeted therapy.

The influence of Citrosept addition to drinking water and Scutellaria baicalensis root extract on the content of selected mineral elements in the blood plasma of turkey hens.

The aim of this research work was to indicate the influence of Citrosept preparation and Scutellaria baicalensis root extract, administered per os to growing turkey hens in 3 different dosages, on the content of selected mineral elements in blood plasma of slaughter turkey hens. An attempt was also made to specify the most effective dosage of the applied preparations with the highest efficiency as regards increased levels of examined macro- and microelements in the birds' blood. The research experiment was conducted on 315 turkey hens randomly divided into seven groups, each consisting of 45 turkey hens. Group K constituted the control group without experimental additions of the above-mentioned preparations. When it comes to turkey hens which belonged to groups II-IV, Citrosept preparation was instilled to water in the following dosages: Group II - 0.011 ml/kg of bm; Group III - 0.021 ml/kg of bm; Group IV - 0.042 ml/kg bm. For birds which belonged to groups V-VII preparation, which was Scutellaria baicalensis root extract, was instilled to water in the following dosages: Group V - 0.009 ml/kg of bm; Group VI - 0.018 ml/kg of bm, Group VII - 0.036 ml/kg bm. In the examined plant extracts and blood plasma of the birds the levels of Na, K, Ca, Mg, Cu, Zn, and Fe were identified. The use of examined extracts influenced the changes in the levels of all tested elements in slaughter turkey hens' blood plasma. An upward tendency was recorded which regarded the level of calcium and magnesium, and a downward tendency of sodium, potassium, copper, zinc, and iron in relation to the results achieved in the control group.

Effect of oral administration of Scutellaria Baicalensis root extract on atopic dermatitis-like skin lesion induced by oxazolone in hairless mice

Effect of oral administration of methanolic extract from Scutellaria baicalensis root (SB) on the development of oxazolone-induced atopic dermatitis-like skin lesions in hairless mice was investigated. Mice were orally administered SB 250, 500 mg/kg/day, or dexamethasone 1 mg/kg/day for 33 days. Oral administration of SB inhibited the development of clinical symptoms, and reduced dermal mast cell infiltration, but did not show definite suppressive effect on elevation of serum total IgE level under experimental condition. Interleukin (IL)-6 level in serum and the mRNA expressions of IL-4, IL-13, IL-12, interfereon-γ, transforming growth factor-β, and fork head box P3 in draining lymph nodes were not significantly affected by SB administration, indicating SB could alleviate atopic dermatitis via the inhibition of mast cell infiltration.

Baicalein and wogonin are activators of rat TREK-2 two-pore domain K+ channel

Earlier studies have shown that TREK-1 and TREK-2 (TREKs), members of the two-pore domain K(+) (K(2P)) channel family that are highly expressed under pathological conditions, are activated by neuroprotective agents. Baicalein and wogonin, oriental flavonoids originating from the root of the medicinal herb Scutellaria baicalensis, are known to have beneficial effects for neuroprotection. However, little is known about the effects of baicalein and wogonin on ion channels including TREKs. We investigated whether baicalein and wogonin modulate the TREK-2 channel, which has been less studied than TREK-1. Single-channel recordings were performed in COS-7 cells transfected with rat TREK-2 and analyzed baicalein- or wogonin-induced channel activity. We found that baicalein and wogonin activated the TREK-2 current by increasing the opening frequency (channel activity: from 0.05 ± 0.01 to 0.17 ± 0.06 in baicalein treatment and from 0.03 ± 0.01 to 0.29 ± 0.09 in wogonin treatment, P < 0.05), while leaving the single-channel conductance and mean open time unchanged. Baicalein continuously activated TREK-2, whereas wogonin transiently activated TREK-2. Application of baicalein and wogonin activated TREK-2 in both cell attached and excised patches, suggesting that baicalein and wogonin may modulate TREK-2 either directly or indirectly with different mechanisms. These results suggest that baicalein- and wogonin-induced TREK-2 activation help set the resting membrane potential of cells exposed to pathological conditions and thus may give beneficial effects in neuroprotection.

Opposite expression of securin and γ‐H2AX regulates baicalein‐induced cancer cell death

Securin and γ-H2AX have been shown to regulate cell survival and genomic stability. However, it is still unknown how the expression and regulation of these proteins is altered following treatment with baicalein, a natural flavonoid extracted from the Scutellaria baicalensis root. In the present study, we investigate the possible roles of securin and γ-H2AX in baicalein-induced cancer cell death. Baicalein reduced cell viability in a variety of human cancer cell lines, including bladder, cervical, colon, and lung cancer cells. Interestingly, baicalein treatment (40-80 µM for 24 h) markedly inhibited securin expression, while the levels of γ-H2AX were elevated. Abnormal spindle formation and chromosomal segregation were induced by baicalein. Furthermore, wild type HCT116 cancer cells had a higher incidence of cytotoxicity and apoptosis than securin-null HCT116 cells following treatment with baicalein. In contrast, baicalein increased the levels of γ-H2AX to a similar extent in both cell types. Transfection with H2AX siRNA further increased baicalein-induced cell death. Additionally, blockade of the AKT pathway by treatment with wortmannin or AKT shRNA lowered the levels of γ-H2AX and enhanced cytotoxicity in baicalein-treated cells. Taken together, our findings suggest that the opposing effects of baicalein on securin and γ-H2AX levels may be involved in the regulation of cell viability and genomic stability by this compound.

Secondary metabolite mapping identifies Scutellaria inhibitors of human lung cancer cells

Scutellaria baicalensis root is widely used in China as an adjuvant to orthodox chemotherapy of lung cancer. However, functional biomarkers of this plant for anti-lung cancer activity have not yet been reported. We therefore determined the growth inhibition activity by MTT assay of eight solvent extracts of S. baicalensis in the human lung cancer cell line SK-MES-1. This activity was then mapped onto the secondary metabolite profile of crude extracts by principal components analysis (PCA) of proton NMR and HPLC-UV data. NMR- and HPLC-PCA maps revealed highest inhibitory activity for the non-aqueous extracts. The first two components of both maps discriminated extract activity mainly based on the differential content of three compounds, which were then tested individually. The IC 50 values for baicalin (IC 50: 64 ± 5 μM), baicalein (IC 50: 80 ± 6 μM) and wogonin (IC 50: 39 ± 10 μM) were comparable to that of the antineoplastic cisplatin (IC 50: 79 ± 16 μM). A partial least squares regression (PLS)-NMR model highly correlated with the corresponding PLS-HPLC model for prediction of inhibition. Secondary metabolite mapping of lung cancer growth inhibitors in crude extracts may be an important first step to qualify Chinese herbal prescriptions required for meaningful clinical trials of such integrated therapies.

Baicalein attenuates oxLDL‐induced oxidative functional damages in endothelial cells

Endothelial apoptosis is a driving force in atherosclerosis development. Oxidized low‐density lipoprotien (oxLDL) pormotes inflammatory and thrombotic processes. Baicalein, a flavonoid obtained from the root of Chinese medicinal herb Scutellaria baicalensis, possesses a multitude of pharmacological activities including anti‐oxidant, anti‐inflammation and anti‐tumor. In this present study, we tested the hypothesis that baicalein could protects vascular endothelial cells against the proatherosclerotic stressor oxLDL and explored the possible mechanisms. Human umbilical vein endothelial cells (HUVECs) were incubated with baicalein (2.5–20 μM) for 2 hours and then incubated with oxLDL (150 μg/ml) for an additional 24 hours. Our results showed that baicalein ameliorated the oxLDL‐diminished eNOS protein expression and reduced the oxLDL‐induced adhesion molecules and the adherence of monocytic THP‐1 cells to HUVECs. Furthermore, several apoptotic features caused by oxLDL including ROS production, intracellular calcium accumulation, mitochondrial membrane potential collapse, disturbed the balance of bcl‐2 family proteins, and triggered subsequent cytochome c release to cytosol and activation of caspase‐3 were attenauted by pretreatment with baicalein. Findings from this study suggest that baicalein may have clinical implications in the prevention of atherosclerotic vascular disease.

Baicalein exerts neuroprotective effects in 6-hydroxydopamine-induced experimental parkinsonism in vivo and in vitro

Baicalein, a flavonoid obtained from the root of Chinese medicinal herb Scutellaria baicalensis, has been shown to exert a protective effect on neurons against several neuronal insults. The aim of this study was to explore the neuroprotective effect of baicalein in 6-hydroxydopamine (6-OHDA)-induced experimental parkinsonism in vitro and in vivo. In in vitro experiments, we found that baicalein (0.5, 5 μg/mL) could significantly ameliorate the 6-OHDA-induced SH-SY5Y cell apoptosis from 31.56% in the 6-OHDA group to 18.90%, 21.61% respectively, and also promote neurite outgrowth of PC12 cell. In in vivo experiments, baicalein had no effect on apomorphine (APO)-induced rotations, but it could significantly attenuate muscle tremor of 6-OHDA-lesioned rats. The burst frequency and amplitude are 13.43%, 35.18% compared to 6-OHDA group. Moreover, baicalein treatment could also increase tyrosine hydroxylase (TH)-positive neurons to 265.52% of the 6-OHDA group. The neuroprotective action of baicalein was coincident with an attenuated astroglial response within the substantia nigra. Neuroprotective effect of baicalein as demonstrated by the increasing the number of dopaminergic neurons may have been, in part, caused by anti-apoptotic, pro-differentiation and anti-inflammatory mechanisms of baicalein. Therefore, baicalein can be a promising candidate for prevention or treatment of Parkinson's disease, owing to its anti-apoptotic, pro-differentiation and anti-inflammatory action.

Validation of a HPLC method for flavonoid biomarkers in skullcap (Scutellaria) and its use to illustrate wide variability in the quality of commercial tinctures.

To compare the flavonoid biomarker content (baicalin, baicalein and wogonin) of eleven commercial tinctures derived from Scutellaria lateriflora aerial parts (n=7) and Scutellaria baicalensis root (n=4). S. lateriflora tinctures are used in by western herbal practitioners to treat anxiety whereas S. baicalensis tinctures are used to treat inflammatory disease. Baicalin and baicalein were purchased from Aldrich Chemical Co. and Wogonin was purchased from ChromaDex. The internal standard (4-hydroxybenzoic acid) was obtained from Acros Organics. The column used was a Luna C18, 5 m (150 x 4.6 mm, Phenomenex) maintained at ambient room temperature. A HP1050 HPLC system was used, comprising a gradient pump with degasser, a variable wavelength UV detector set to 270 nm, and an autosampler. Gradient elution was performed using 0.1% formic acid (eluent A) and methanol (eluent B). The gradient elution initial conditions were 45% B with linear gradient to 60% from 2 to 10 min, followed by linear gradient to 70% B at 30 min, and then linear gradient to 99% B at 31 min, this proportion being maintained for 1 min. The mobile phase was then returned to initial conditions at 33 min and maintained until the end of the run at 35 min. The flow rate was 1 mL/min. The assay was validated for sensitivity, accuracy and reproducibility. The concentration range of biomarkers (baicalin, baicalein and wogonin) in commercial tinctures is reported for S. lateriflora (baicalin: 0-12.66 mg/mL; baicalein: 0-0.63 mg/mL; wogonin: 0-0.16 mg/mL) and for S. baicalensis (baicalin: 0.12-10.61 mg/mL; baicalein: 0.52-5.88 mg/mL; wogonin: 0.08-1.61 mg/mL). The wide variability in biomarker concentrations between commercial tinctures has important implications for the manufacturers of commercial tinctures, for herbal practitioners in the choice of tinctures and not least for pharmacology and clinical researchers.

Identification and quantification of eight flavones in root and shoot tissues of the medicinal plant Huang-qin (Scutellaria baicalensis Georgi) using high-performance liquid chromatography with diode array and mass spectrometric detection

A method of analysis of eight flavones using high-performance liquid chromatography (HPLC)-diode array detection (DAD)-mass spectrometry (MS) in root and aerial tissues of the medicinal plant Scutellaria baicalensis was developed. The identity of the analytes was confirmed using retention time, UV-vis and mass spectral comparisons to commercial standards. Both UV-vis and mass spectral patterns were characterized for glycosylated flavones. Two additional flavone glycosides were tentatively identified as chrysin-7-glucuronide and wogonoside, but not quantified. Greenhouse and in vitro-grown tissues were analyzed with flavone concentrations ranges of 0.14-150 and 0.030-1.7 microg/mg for greenhouse root and shoot tissue, respectively, and 0.0068-6.4 and 0.082-1.5 microg/mg for in vitro-grown roots and shoots, respectively.

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.

Flavonoid baicalein attenuates activation-induced cell death of brain microglia.

Baicalein (5,6,7-trihydroxyflavone), a flavonoid originated from the root of Chinese medicinal herb Scutellaria baicalensis, has been shown to exert anti-inflammatory and antioxidant effects, and it is a well known inhibitor of 12-lipoxygenase. We have previously reported that neuroglia undergo nitric oxide (NO)-dependent and NO-independent apoptosis upon inflammatory activation. In the current work, we asked how anti-inflammatory baicalein influences autoregulatory apoptosis of activated microglia and their NO production. Baicalein attenuated NO production and apoptosis of lipopolysaccharide (LPS)-activated, but not interferon-gamma-activated, BV-2 mouse microglial cells as well as rat primary microglia cultures. The inhibition of NO production by baicalein was due to the suppression of inducible NO synthase induction. Moreover, baicalein inhibited LPS-induced nuclear factor-kappaB (NF-kappaB) activity in BV-2 cells without affecting caspase-11 activation, interferon regulatory factor-1 induction, or signal transducer and activator of transcription-1 phosphorylation. Transfection of BV-2 cells with a p65 subunit of NF-kappaB abolished the apoptosis-attenuating effects of baicalein, indicating that the inhibition of NF-kappaB is a major mechanism of action. Baicalein, however, did not significantly affect NO donor-mediated cytotoxicity, and the apoptosis-attenuating effects of baicalein were independent of 12-lipoxygenase inhibition. Based on our previous findings that activation-induced cell death (AICD) of microglia occurs through two separate pathways (NO-dependent pathway and caspase-11-dependent pathway), our current results suggest that baicalein selectively inhibits the NO-dependent apoptotic pathway of activated microglia by suppressing cytotoxic NO production. Also, the AICD-inhibiting effects of baicalein were specific for the inflammatory stimulus that activated microglia.

Effects of baicalein isolated from roots ofScutellaria baicalensis Georgi on interleukin 1β- and tumour necrosis factor α-induced tissue-type plasminogen activator and plasminogen activator inhibitor-1 production in cultured human umbilical vein endothelial cells

The effects were examined of baicalein on tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) production stimulated by interleukin-1α (IL-1β) and tumour necrosis factor-α (TNF-α) in cultured human vein umbilical endothelial cells (HUVECs). IL-1β and TNF-α increased PAI-1 production, but they decreased t-PA production. Baicalein isolated from the roots of Scutellaria baicalensis Georgi, inhibited the PAI-1 production stimulated by IL-1β and TNF-α, but it had no effect on the t-PA. In addition, protein kinase C (PKC) inhibitors such as H7 and sphingosine decreased the reduction of t-PA and the increase of PAI-1 by IL-1β and TNF-α. On the other hand, dibutryl cAMP and forskolin had no effect on the t-PA reduction and PAI-1 increase by IL-1β and TNF-α. Moreover, IL-1β and TNF-α did not cause [Ca2+] elevation. These results suggest that the inhibitory action of baicalein on the PAI-1 production by both cytokines might be directly mediated through PKC inhibition. © 1997 John Wiley & Sons, Ltd.

Anti-influenza virus activity of plant flavonoid, 5,7,4′-trihydroxy-8-methoxyflavone, from the roots of scutellaria baicalensis and enhancement of its activity by drug delivery system (DDS) : T. Nagai a, Y. Nishibe b, Y. Makino b, T. Tomimori c and H. Yamada a aOriental Medicine Research Center, The Kitasato Institute, Tokyo 108, Japan, bPharmaceutical Products Research Laboratories, Teijin Limited, Tokyo 191, Japan and

Anti-influenza virus activity of plant flavonoid, 5,7,4′-trihydroxy-8-methoxyflavone, from the roots of scutellaria baicalensis and enhancement of its activity by drug delivery system (DDS) : T. Nagai a, Y. Nishibe b, Y. Makino b, T. Tomimori c and H. Yamada a aOriental Medicine Research Center, The Kitasato Institute, Tokyo 108, Japan, bPharmaceutical Products Research Laboratories, Teijin Limited, Tokyo 191, Japan and

Effects of certain herbal medicines on the biotransformation of arachidonic acid: a new pharmacological testing method using serum

Two in vitro experimental systems were compared to evaluate the pharmacological effects of some herbal medicines on the biotransformation of arachidonic acid (AA) using the microsomal fraction of sheep vesicular glands as an enzyme source. The first system involved the addition of serum obtained from rats treated orally with the herbal medicines, while the second system involved the direct addition of herbal medicine extracts to the enzyme medium. Both systems were performed in parallel. Indomethacin, used as a reference drug, inhibited AA biotransformation in a dose-dependent manner in both experimental systems. The serum of rats orally pretreated for 1 h with Coptis japonica rhizome and Paeonia lactiflora root also inhibited AA biotransformation. Direct addition of hot water extracts of Rheum officinale rhizome, Scutellaria baicalensis root, Paeonia moutan bark and Zingiber officinale rhizome also inhibited AA biotransformation, while the extracts of Coptis japonica rhizome and Paeonia lactiflora root showed no effects.