Preparation and characterization of the inclusion complex of Baicalin (BG) with beta-CD and HP-beta-CD in solution: an antioxidant ability study

The formation of the complexes of BG with beta-CD and HP-beta-CD was studied by UV-vis absorption spectroscopy, fluorescence spectra, Phase-solubility measurements and nuclear magnetic resonance spectroscopy (NMR) in solution. The formation constants (K) of complexes were determined by fluorescence method and Phase-solubility measurements. The results showed that the inclusion ability of beta-CD and its derivatives was the order: HP-beta-CD>beta-CD. In addition, the experimental resulted confirmed the existence of 1:1 inclusion complex of BG with CDs. The antioxidant ability studies of BG and CDs complexes were done. The results obtained indicated that the BG/HP-beta-CD complex was the most reactive form, and then was the BG/beta-CD complex; the last was BG. Special configuration of complex has been proposed on NMR technique.

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.

Bifunctional effects of O-methylated flavones from Scutellaria baicalensis Georgi on melanocytes: Inhibition of melanin production and intracellular melanosome transport

The growing interest in skin lightening has recently renewed attention on the esthetic applications of Chinese herbal medicine. Although Scutellaria baicalensis Georgi is used for antipyretic and antiinflammatory purposes, its whitening effect remains unclear. This study reports three major findings: (1) S. baicalensis has a potent inhibitory effect on melanogenesis; (2) wogonin and its glycoside are the active components of S. baicalensis; and (3) O-methylated flavones from S. baicalensis, such as wogonin, inhibit intracellular melanosome transport. Using a melanin quantification assay, we showed that S. baicalensis potently inhibits melanogenesis in B16F10 cells. Componential analyses revealed that the main components of S. baicalensis are baicalin, wogonoside, baicalein, wogonin, and oroxylin A. Among these five flavones, wogonin and wogonoside consistently inhibited melanogenesis in both B16F10 melanoma cells and primary melanocytes. Wogonin exhibited the strongest inhibition of melanin production and markedly lightened the color of skin equivalents. We identified microphthalmia-associated transcription factor and tyrosinase-related proteins as potential targets of wogonin- and wogonoside-induced melanogenesis suppression. In culture, we found that the melanosomes in wogonin-treated B16F10 cells were localized to the perinuclear region. Immunoblotting analyses revealed that wogonin significantly reduced in melanophilin protein, which is required for actin-based melanosome transport. Other actin-based melanosome transport-related molecules, i.e., Rab27A and myosin Va, were not affected by wogonin. Cotreatment with MG132 blocked the wogonin-induced decrease in melanophilin, suggesting that wogonin promotes the proteolytic degradation of melanophilin via the calpain/proteasomal pathway. We determined that the structural specificities of the mono-O-methyl group in the flavone A-ring and the aglycone form were responsible for reducing melanosome transport. Furthermore, wogonin and two wogonin analogs, mono-O-methyl flavones, strongly suppressed melanosome transport. Our findings suggest the applicability of S. baicalensis in the esthetic field. Thus, we propose a novel pharmacologic approach for the treatment of hyperpigmentation.

Scutellarin from Scutellaria baicalensis suppresses adipogenesis by upregulating PPARα in 3T3-L1 cells

Adipocyte dysfunction is a major cause of obesity, which is associated strongly with many disorders including psychological and medical morbidities, metabolic abnormalities, and cardiovascular diseases as well as a series of cancers. This study investigated the antiadipogenic activity of scutellarin (1) in 3T3-L1 preadipocytes as well as the underlying molecular mechanisms. It was observed that 1 reduced adipocyte differentiation of 3T3-L1 cells potently, as evidenced by a decrease in cellular lipid accumulation. At the molecular level, mRNA expression of the master adipogenic transcription factors, PPARγ and C/EBPα, was decreased markedly. However, mRNA levels of C/EBPβ, the upstream regulator of PPARγ and C/EBPα, were not decreased by 1. Moreover, a dose-dependent upregulation of PPARα was observed for 1. Computational modeling indicated that 1 can bind to PPARα, γ, and δ each in a distinct manner, while it can activate PPARα only by forming a hydrogen bond with Y464, thus stabilizing the AF-2 helix and activating PPARα. Therefore, these results suggest that 1, a major component of Scutellaria baicalensis, attenuates fat cell differentiation by upregulating PPARα as well as downregulating the expression of PPARγ and C/EBPα, thus showing therapeutic potential for obesity-related diseases.

Wogonin but not Nor-wogonin inhibits lipopolysaccharide and lipoteichoic acid-induced iNOS gene expression and NO production in macrophages

Wogonin (Wog; 5,7-dihydroxy-8-methoxy flavone) has been shown to effectively inhibit lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) gene expression and nitric oxide production in our previous study. In the present study, we found that Nor-wogonin (N-Wog; 5,7,8-trihydroxyl flavone), a structural analogue of Wog with an OH substitution at C8, performed different effect on LPS- or lipoteichoic acid (LTA)-induced iNOS gene expression and nitric oxide (NO) production in macrophages. Wog, but not N-Wog, significantly inhibits LPS- or LTA-induced NO production through suppressing iNOS gene expression at both protein and mRNA without affecting NO donor sodium nitroprusside-induced NO production, NOS enzyme activity, and cells viability. Activation of JNKs (not ERKs) via phosphorylation induction, and an increase in c-Jun (not c-Fos) protein expression were involved in LPS- and LTA-treated RAW264.7 cells, and those events were blocked by Wog, but not N-Wog, addition. Furthermore, 5,7-diOH flavone, but not 5-OH flavone, 7-OH flavone, 5-OH-7-OCH(3) flavone, significantly inhibits LPS-induced iNOS protein expression and NO production, and 7,8-diOCH(3) flavone performs more effective inhibitory activity on LPS-induced NO production and iNOS protein expression than 7-OCH(3)-8-OH flavone. These data suggest that OHs at both C5 and C7 are essential for NO inhibition of flavonoids, and OCH(3) at C8 may contribute to this activity, and suppression of JNKs-c-Jun activation is involved.

Inhibitory Effects of Scutellaria baicalensis Root Extract on Linoleic Acid Hydroperoxide-induced Lung Mitochondrial Lipid Peroxidation and Antioxidant Activities

In this study, we evaluated the ability of Scutellaria baicalensis Georgi to protect lipid-peroxidation (LPO) in lung tissue after free radical-induced injury. We prepared S. baicalensis root (SBR) extracts using different solvents. The total flavonoid and total phenol contents of each extract were measured, and the ROS damage protection was evaluated by analyzing linoleic acid hydroperoxide (LHP)-induced LPO in rat lung mitochondria. Moreover, evaluating diphenylpicrylhydrazyl (DPPH), hydrogen peroxide, superoxide anion radical, and hydroxyl radical scavenging abilities and using metal chelating assays were used to determine in vitro antioxidant activity. The ethyl acetate (EtOAc) extract showed high ROS scavenging ability, and four compounds were subsequently isolated and purified from this extract: baicalin, baicalein, wogonin, and oroxylin A. Baicalein in rat lung mitochondria the most significant LHP-induced LPO inhibition was shown and extracted with EtOAc that contained the highest amount of baicalein. Thus, baicalein and the EtOAc extract of SBR may be efficient in conferring ROS damage protection and inhibiting LHP-induced LPO in rat lung mitochondria. Additional studies are warranted to investigate their use as antioxidant therapy for respiration infections, nutrition supplements, and lead compounds in pharmaceuticals.

Skullcap (Scutellaria baicalensis) extract and its active compound, wogonin, inhibit ovalbumin-induced Th2-mediated response

Skullcap (Scutellaria baicalensis) has been widely used as a dietary ingredient and traditional herbal medicine owing to its anti-inflammatory and anticancer properties. In this study, we investigated the anti-allergic effects of skullcap and its active compounds, focusing on T cell-mediated responses ex vivo and in vivo. Splenocytes from mice sensitized with ovalbumin (OVA) were isolated for analyses of cytokine production and cell viability. Mice sensitized with OVA were orally administered skullcap or wogonin for 16 days, and then immunoglobulin (Ig) and cytokine levels were measured by enzyme-linked immunosorbent assays. Treatment with skullcap significantly inhibited interleukin (IL)-4 production without reduction of cell viability. Moreover, wogonin, but not baicalin and baicalein, suppressed IL-4 and interferon-gamma production. In vivo, skullcap and wogonin downregulated OVA-induced Th2 immune responses, especially IgE and IL-5 prediction. Wogonin as an active component of skullcap may be applied as a therapeutic agent for IgE- and IL-5-mediated allergic disorders.

Scutellaria baicalensis Alleviates Insulin Resistance in Diet-Induced Obese Mice by Modulating Inflammation

Insulin resistance is strongly associated with the metabolic syndrome, and chronic inflammation is known to be a major mechanism of insulin resistance and is a therapeutic target. This study was designed to evaluate the effect of Scutellaria baicalensis (SB) in high-fat diet (HFD)-induced insulin-resistant mice and to investigate its mechanism based on inflammatory responses. Mice were fed a HFD to induce insulin resistance and then administered SB for nine weeks. Body weight, glucose, lipid, insulin, epididymal fat pad and liver weights, and histologic characteristics were evaluated to determine the effect on insulin resistance. In order to evaluate the effects on the inflammatory process, we analyzed the proportions of macrophages in liver and epididymal fat and measured inflammatory gene expression. Fasting and postprandial glucose, fasting insulin, HOMA-IR, triglycerides, and low density lipoprotein cholesterol levels were significantly decreased by SB administration. The epididymal fat and liver showed significant weight decreases and histological improvements. Total adipose tissue macrophages (ATMs) decreased (27.71 ± 3.47% vs. 45.26 ± 7.26%, p < 0.05), M2 ATMs increased (47.02 ± 6.63% vs. 24.28 ± 8.00%, p < 0.05), and CD11b⁺ Kupffer cells decreased. The expression levels of tumor necrosis factor alpha and F4/80 in the liver were significantly decreased (12.03 ± 1.47% vs. 25.88 ± 4.57%, p < 0.05) compared to HFD group. These results suggest that SB improved insulin resistance through inhibition of macrophage-mediated inflammation.

Deep Eutectic Solvent-Based Ultrahigh Pressure Extraction of Baicalin from Scutellaria baicalensis Georgi

Deep eutectic solvents (DESs), promising green solvents, and ultrahigh pressure extraction (UPE) as an effective auxiliary extraction method, have attracted wide attention. In this study, DES was coupled with UPE to efficiently extract baicalin from Scutellaria baicalensis Georgi. First, choline chloride: lactic acid (ChCl-LA, molar ratio 1:1) was selected as the most appropriate DES by comparing the extraction yield of different DESs. Second, the extraction protocol was optimized by response surface methodology (RSM) considering the impacts of ChCl-LA concentration, extraction pressure, extraction time and liquid-solid ratio on the extraction yield. Under the optimal condition (40 vol% water content, extraction pressure of 400 MPa, extraction time of 4 min and a liquid-solid ratio of 110 mL/g), a maximum yield of 116.8 mg/g was achieved, higher than that obtained by the traditional extraction method. The microstructure of the raw and extracted Scutellaria baicalensis Georgi samples according to scanning electron microscope (SEM) images revealed that the dissolution of chemical components was enhanced from the disrupted root tissues after DESs-UPE. DESs coupled with UPE could effectively extract the baicalin from Scutellaria baicalensis Georgi as a rapid and efficient extraction method.

Biphasic effects of baicalin, an active constituent of Scutellaria baicalensis Georgi, in the spontaneous sleep-wake regulation

AIM OF THE STUDY

Baicalin is an active compound originating from the root of Scutellaria baicalensis Georgi, which has been used for anti-inflammation, anti-bacteria, anti-hypertension, anti-allergy and sedation since ancient China, though the neuronal mechanisms involved in the sedative effect is still unclear. Baicalin possesses the ability to decrease the expression of pro-inflammatory cytokines and nuclear factor (NF)-κB activity. Furthermore, baicalin has demonstrated an anxiolytic-like effect via activation of γ-aminobutyric acid-A (GABA(A)) receptors. Pro-inflammatory cytokines (e.g. interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α) and the GABAergic system promote sleep. This study was designed to determine whether the GABA(A) receptor activation and/or the suppression of pro-inflammatory cytokines mediate(s) baicalin-induced sleep alterations.

MATERIALS AND METHODS

Baicalin was intracerebroventricularly (ICV) administered 20 min either prior to the beginning of the light period or before the onset of the dark period. Electroencephalogram (EEG) and gross body movement were acquired for sleep analysis. Pharmacological blockade of IL-1 and GABA(A) receptors were employed to elucidate the involvements of IL-1 and GABA(A) receptors in baicalin-induced sleep alterations. IL-1β concentrations obtained after baicalin administration in several distinct brain regions were determined by ELISA.

RESULTS

ICV administration of baicalin decreased slow wave sleep (SWS) during the first 2h of the light period. Rapid eye movement sleep (REMS) was not altered. The blockade of IL-1β-induced SWS enhancement by baicalin suggests that the antagonism of IL-1 receptors is involved in baicalin-induced SWS decrement during the light period. However, IL-1β concentrations during the light period were not altered after baicalin administration. In contrast, baicalin increased both SWS and REMS during hours 8-10 of the dark (active) period when baicalin was administered at the beginning of the dark period, and its effects were blocked by the GABA(A) receptor antagonist bicuculline.

CONCLUSION

Baicalin exhibits biphasic effects on sleep-wake regulation; the decrease of SWS during the light period and increases of SWS and REMS during the dark period. Inhibition of IL-1 action and enhancement of GABA(A) receptor activity may mediate baicalin's effects during the light and dark period, respectively.

Gene expression profiling and pathway network analysis of hepatic metabolic enzymes targeted by baicalein

ETHNOPHARMACOLOGICAL RELEVANCE

Baicalein is a flavone originally isolated from the roots of traditional Chinese medicinal herb, Scutellaria baicalensis, which has been proved as a promising chemopreventive compound for many chronic human diseases.

AIM OF THE STUDY

The present study aimed to clarify the molecular mechanism targeted by baicalein.

MATERIALS AND METHODS

Gene expression profiling of HepG2 cells treated with baicalein was carried out, using the Affymetrix 42K oligonucleotide microarray in the present study. Microarray data analyzed by Ingenuity Pathway Analysis (IPA), further study performed by real time PCR, reporter gene assay, and Western blot.

RESULTS

Among total 42K gene probes, baicalein treatment up-regulated the signals of 440 gene probes (1.04% of total gene probes) and down-regulated signals of 254 gene probes (0.6% of total gene probes) by ≥2-fold. These genes were categorized into 35 groups and hit for biological processes, molecular functions, and signaling pathways. The network and pathway analyses of these data further revealed that an Nrf2 (nuclear factor-erythroid 2 p45-related factor 2)-mediated ARE (antioxidant response element) pathway is involved in baicalein-induced gene expression of hepatic metabolic enzymes. The representative enzymes involved in Nrf2/ARE pathway were further confirmed at mRNA level by real time PCR and at protein level by Western blot analysis. Moreover, the ARE-reporter gene assay demonstrated that baicalein stimulated Nrf2-mediated ARE transactivation.

CONCLUSIONS

Our results provide a comprehensive data for understanding the hepatic metabolism, bioactive role and the molecular mechanisms of baicalein.

Flavones Isolated from Scutellariae radix Suppress Propionibacterium Acnes-Induced Cytokine Production In Vitro and In Vivo

Scutellariae radix, the root of Scutellaria baicalensis, has long been applied in traditional formulations and modern herbal medications. Propionibacterium acnes (P.acnes) in follicles can trigger inflammation and lead to the symptom of inflammatory acnes vulgaris. This study was aimed at evaluating the effect of Scutellariae radix extract and purified components isolated from it on inflammation induced by P.acnes in vitro and in vivo. The results showed the ethyl acetate (EA) soluble fraction from the partition of crude ethanolic extract from Scutellariae radix inhibited P.acnes-induced interleukin IL-8 and IL-1β production in human monocytic THP-1 cells. Seven flavones were isolated from the EA fraction by repeated chromatographies, and identified as 5,7-dihydroxy-6-methoxyflavone (FL1, oroxylin), 5,7-dihydroxy-8-methoxyflavone (FL2, wogonin), 5-hydroxy-7,8-dimethoxyflavone (FL3, 7-O-methylwogonin), 5,6′-dihydroxy-6,7,8,2′-tetramethoxy flavone (FL4, skullcapflavone II), 5,7,4′-trihydroxy-8-methoxyflavone (FL5), 5,2′,6′-trihydroxy-7,8-dimethoxyflavone (FL6, viscidulin II), and 5,7,2′,5′-tetrahydroxy-8,6′-dimethoxyflavone (FL7, ganhuangenin). They all significantly suppressed P. acnes-induced IL-8 and IL-1β production in THP-1 cells, and FL2 exerted the strongest effect with half maximal inhibition (IC₅₀) values of 8.7 and 4.9 μM, respectively. Concomitant intradermal injection of each of the seven flavones (20 μg) with P. acnes effectively attenuated P. acnes-induced ear swelling, and decreased the production of IL-6 and tumor necrosis factor-α in ear homogenates. Our results suggested that all the seven flavones can be potential therapeutic agents against P. acnes-induced skin inflammation.

Amelioration of hyperglycaemia and hyperlipidaemia by adjusting the interplay between gut microbiota and bile acid metabolism: Radix Scutellariae as a case

BACKGROUND

Our previous clinical research showed that the interaction between gut microbiota and bile acids (BAs) in patients with type 2 diabetes mellitus (T2DM) changed significantly. We hypothesized that T2DM could be improved by adjusting this interaction mediated by farnesoid X receptor (FXR). T2DM belongs to the category of "xiaoke" in traditional Chinese medicine. Radix scutellariae has the effects of clearing away heat and eliminating dampness, curing jaundice and quenching thirst and is widely used alone or in combination with other medicines for the treatment of T2DM in China and throughout Asia. Additionally, the interaction between Radix scutellariae and gut microbiota may influence its efficacy in the treatment of T2DM.

PURPOSE

This study chose Radix scutellariae to validate that T2DM could improve by adjusting the interaction between gut microbiota and bile acid metabolism.

STUDY DESIGN AND METHODS

Radix scutellariae water extract (WESB) was administered to a T2DM rat model established by a high-fat diet combined with streptozotocin. The body weight and blood glucose and insulin levels were measured. The levels of serum lipids, creatinine, uric acid, albumin and total bile acid were also detected. Changes in the pathology and histology of the pancreas, liver and kidney were observed by haematoxylin-eosin staining. The 16S rRNAs of gut microbiota were sequenced, and the faecal and serum BAs were determined by liquid chromatography tandem mass spectrometry. The expression levels of BA metabolism-associated proteins in the liver and intestine were evaluated by immunoblot analysis.

RESULTS

The results showed that WESB improved hyperglycaemia, hyperlipaemia, and liver and kidney damage in T2DM rats. In addition, the abundances of key gut microbiota and the concentrations of certain secondary BAs in faeces and serum were restored. Moreover, there was a significant correlation between the restored gut microbiota and BAs, which might be related to the activation of liver cholesterol 7α-hydroxylase (CYP7A1) and the inhibition of FXR expression in the intestine rather than the liver.

CONCLUSIONS

This study provided new ideas for the prevention or treatment of clinical diabetes and its complications by adjusting the interaction between gut microbiota and bile acid metabolism.

Orthogonal array design for the optimization of supercritical fluid extraction of baicalin from roots of Scutellaria baicalensis Georgi

Supercritical fluid was used to extract baicalin from the roots of Scutellaria baicalensis Georgi. An orthogonal array design (OAD), OA(9)(3(4)), was employed as a chemometric method for the optimization of the supercritical fluid extraction of baicalin from the herbal medicine. Four parameters, namely, modifiers, temperature and pressure of supercritical fluid, and the dynamic extraction time, were studied and optimized by a three-level OAD in which the interactions between the parameters were neglected. Determinations of the extracts were performed by high-performance liquid chromatography. The effects of parameters were studied using analysis of variance. The results showed that selection of the modifier was the main factor in attaining higher yields of baicalin. While the other three factors had some effect on the extraction of the compound, the effect was much less than that of the modifiers. 1,2-Propanediol-modified supercritical fluid was more effective than 95% ethanol-modified supercritical carbon dioxide or methanol-modified supercritical carbon dioxide for the extraction of baicalin from the solid matrix. Finally, experimental conditions were proposed which can provide the highest extraction yield with respect to the considered factors.

Scutellaria baicalensis alleviates cantharidin-induced rat hemorrhagic cystitis through inhibition of cyclooxygenase-2 overexpression

Cantharidin, an active component in mylabris, is used in traditional Chinese medicine (TCM) to treat scabies and hepatoma, but accompanied by hemorrhagic cystitis. Evidence shows that cantharidin induces human bladder carcinoma cell death through COX-2 overexpression in vitro. In TCM, Scutellaria baicalensis is usually used to cure mylabris-induced hematuria. This work was undertaken to determine the mechanisms of cantharidin-induced rat hemorrhagic cystitis and explore the uroprotective effect of S. baicalensis. In vitro results showed cantharidin could induce cytotoxicity through prostaglandin (PG)E₂ overproduction of T24 cells. Boiling-water extract of S. baicalensis (SB-WE) could significantly inhibit PGE₂ production and COX-2 expression in lipo-polysaccharide-induced RAW 264.7 cells, indicating obvious anti-inflammatory abilities. In vivo results indicated that cantharidin caused rat hemorrhagic cystitis with hematuria via c-Fos and COX-2 overexpression. SB-WE was given orally to cantharidin-treated rats, whereby hematuria level, elevated PGE₂ and COX-2 protein overexpression were significantly and dose-dependently inhibited by SB-WE. The anti-inflammatory components of SB-WE are baicalin and wogonin, whose contents were 200.95 ± 2.00 and 31.93 ± 0.26 μg/mg, respectively. In conclusion, cantharidin induces rat cystitis through c-Fos and COX-2 over-expression and S. baicalensis can prevent the resulting hematuria because of its anti-inflammatory effects.

Scutellaria baicalensis and a constituent flavonoid, baicalein, attenuate ritonavir-induced gastrointestinal side-effects

Ritonavir, a protease inhibitor drug, is commonly used in AIDS therapy. As with other chemotherapeutic drugs that cause gastrointestinal adverse effects, ritonavir treatment is associated with significant nausea and vomiting. This study investigated whether Scutellaria baicalensis, and its active flavonoid constituent, baicalein, attenuate the gastrointestinal effects of ritonavir. The effects of herb administration were evaluated in ritonavir-treated rats using a rat pica model, which simulates nausea and vomiting in humans. The effects of herb administration on gastric emptying in rats were also measured. Ritonavir treatment resulted in increased kaolin intake or severe pica, the intensity of which was reduced significantly with S. baicalensis administration (1 mg kg(-1); P<0.05). High-performance liquid chromatography analysis of S. baicalensis showed the presence of an extremely potent flavonoid constituent, baicalein. The study aimed to determine if baicalein contributed to the anti-pica effect of the extract. It was observed that baicalein dose-dependently decreased pica in ritonavir-treated rats (P<0.001). In addition to inducing pica, ritonavir also significantly delayed gastric emptying, which could contribute to ritonavir-induced gastrointestinal dysfunction. When S. baicalensis extract was administered to ritonavir-treated rats the delayed gastric emptying was significantly attenuated (P<0.05). The results suggest that S. baicalensis and the constituent baicalein reduce the gastrointestinal dysfunction caused by ritonavir. It is concluded that S. baicalensis may potentially have a role to play in reducing drug-induced adverse effects.

Anti-nociceptive mechanism of baicalin involved in intervention of TRPV1 in DRG neurons in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellaria baicalensis Georgi (Lamiaceae) is often included as an ingredient in traditional Chinese compound prescriptions for the treatment of fever-related or inflammatory conditions.

AIM OF THE STUDY

The present work was to further uncover the analgesic mechanisms of baicalin (a known principal constituent of Scutellaria baicalensis) by investigating its effects on the expression of TRPV1 mRNA as well as on its functions as mediators of calcium entrance into the cytoplasm of dorsal root ganglion (DRG) neurons in vitro.

MATERIALS AND METHODS

By using CPT as an agent to eliminate the non-neuronal cells and using serum-free neurobasal as culture medium, primary cultures of rat DRG neurons with high purity and viability were established. On this basis, effects of baicalin on both the expression of TRPV1 mRNA and on the function of TRPV1 in vitro under two various temperature conditions were studied. The TRPV1 mRNA expression levels were examined by using qRT-PCR and analyzed by the method of 2(-DeltaDeltaCT). The elevation amplitudes of intracellular [Ca(2+)]i evoked by TRPV1 agonist capsaicin in DRG neurons were examined by the calcium fluorescence imaging method under confocal microscopy.

RESULTS

Baicalin was shown to down-regulate the mRNA expression levels of TRPV1 at both 37 and 39 degrees C, and under the latter temperature, the intracellular fluorescent intensity evoked by capsaicin was significantly decreased following incubation with baicalin in vitro. We also demonstrated that the actions of baicalin to TRPV1 were not achieved through pathways of TRPA1 or TRPV subfamily members.

CONCLUSIONS

Collectively, these results provide compelling evidence that the down-regulated actions of baicalin to TRPV1 in DRG neurons might account for part of the anti-nociceptive mechanism of baicalin.

Total flavonoid aglycones extract in Radix Scutellariae induces cross-regulation between autophagy and apoptosis in pancreatic cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Scutellariae (RS), the dried root of Scutellariae baicalensis Georgi, known as a herbal medicine in several Asian countries including China, has been widely used to treat inflammation, hypertension, cardiovascular disease as well as cancer. The total flavonoid aglycone extracted (TFAE) was extracted by ethyl acetate and this extraction methodology was optimized and obtained the protection of Chinese patents.

AIM OF THE STUDY

To investigate the underlying mechanism of the chemotherapeutic effects of TFAE in inducing autophagy and apoptosis in pancreatic cancer cells in vitro and in vivo.

MATERIALS AND METHODS

We performed CCK8 assays, AnnexinV-FITC/PI staining, flow cytometry assays, transmission electron microscopy, immunofluorescence analysis and Western blot to study the molecular mechanism of TFAE in inducing autophagy and apoptosis in pancreatic cancer cells in vitro and in vivo.

RESULTS

In vitro, TFAE exhibits significant anti-tumor activity against pancreatic cancer cell lines, especially for BxPC3 (IC₅₀ = 6.5 μg mL^-1). Moreover, TFAE induces apoptosis and autophagy as evidenced by the increased apoptosis or autophagy-related protein level, the increased the fraction of apoptotic cells and the punctuate patterns of LC3 II. Furthermore, TFAE induce autophagy through PI3K/Akt/mTOR inhibition. Interestingly, pharmacological block autophagy by 3-MA enhanced TFAE-induced apoptosis, indicating that TFAE induced autophagy functions as a cytoprotective process against apoptosis. In vivo, 150 mg/kg TFAE inhibited the BxPC3 tumor growth in immune deficient mice with the inhibitory rate of 66.87% and induced both apoptosis and autophagy.

CONCLUSION

TFAE have anti-tumor activity against pancreatic cancer and can induce apoptosis and autophagy through PI3K/Akt/mTOR signal pathway. TFAE might be a potential anticancer drug to be further developed for human pancreatic cancer therapy.

Comparative Investigation for Rotten Xylem (kuqin) and Strip Types (tiaoqin) of Scutellaria baicalensis Georgi Based on Fingerprinting and Chemical Pattern Recognition

Scutellaria baicalensis Georgi (SBG) is not just as a traditional herbal medicine but also a popular functional food in China and other Asian countries. A sensitive simple strategy was developed for the first time to analyze SBG from eight different geographical sources using high-performance liquid chromatography (HPLC) coupled with multivariate chemometric methods. Two unsupervised pattern recognition models, hierarchical cluster analysis (HCA) and principal components analysis (PCA), and a supervised pattern recognition model, partial least squares discriminant analysis (PLS-DA), were used to analyze the chemical compositions and physical traits of SBG. The important chemical markers baicalin, baicalein, and wogonoside were analyzed quantitatively and with PLS-DA. These methods distinguished rotten xylem (kuqin) and strip types (tiaoqin) of SBG and found that the thickness of the slice had a significant impact on the classification of SBG. Two classes of strip types were identified: one as the uncut pharmaceutical, which was sectioned with a thickness >3 mm; the other as a thin-sectioned strip type, with a thickness of <2 mm. This fingerprinting technique coupled to a chemometric analysis was used for the simultaneous quantitation of three components (chemical markers) of SBG, and greatly simplified the complicated identification of the multiple components of this plant relative to traditional methods. The strategy can clearly distinguish between kuqin and tiaoqin of SBG, and suggests that the thickness of the slice can be used as the basis for evaluation of SBG. These data provide a theoretical basis and scientific evidence for the development and utilization of SBG.

Korean Scutellaria baicalensis Georgi methanol extracts inhibits metastasis via the Forkhead Box M1 activity in hepatocellular carcinoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellaria baicalensis Georgi, commonly known as skullcaps, and it has been widely used as traditional therapeutic herb in several eastern Asia including Korea, China and Japan because of its remarkable anti-inflammatory and anti-cancer effects. Our study focuses on the anti-metastatic effects of Scutellaria baicalensis Georgi in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Methanol extract of Scutellaria baicalensis Georgi was examined for identification of its composition by HPLC-MS/MS. The extract was evaluated for the anti-metastasis activity using HepG2 hepatocellular carcinoma cells via immunoblotting and RT-PCR. For mechanical study, specific Forkhead Box M1 (FOXM1) vector was transfected to HepG2 cells.

RESULTS

Scutellaria baicalensis Georgi potentially inhibited proliferation of HepG2 cells dose dependently. Scutellaria baicalensis Georgi decreased metastasis through the regulation of matrix metalloproteinase 2 (MMP-2) and FOXM1 activities at the transcription and translation levels.

CONCLUSIONS

The results of the present study suggest that Scutellaria baicalensis Georgi could be a potent chemotherapeutic agent against HCC. Its clinical use guarantee for further study and individual flavonoids from Scutellaria baicalensis Georgi should also be investigated.

Increased oral AUC of baicalin in streptozotocin-induced diabetic rats due to the increased activity of intestinal beta-glucuronidase

The purpose of the study was to investigate the pharmacokinetics of baicalin, a major bioactive component of Scutellariae radix, in diabetic conditions. The 4-week diabetic rats were induced by intraperitoneal administration of streptozotocin. Plasma concentrations of baicalin were measured following oral (200 mg/kg) or intravenous (12 mg/kg) administration. Everted intestinal transport, intestinal mucosal metabolism of baicalin and intestinal beta-glucuronidase activity were also investigated. It was found that the diabetic condition significantly increased the exposure of baicalin following oral doses (AUC 100.77 +/- 4.16 microg x h/mL in diabetic rats vs. 48.48 +/- 7.94 microg x h/mL in normal rats). In contrast, the diabetic condition significantly decreased the exposure of baicalin following intravenous doses (AUC 11.20 +/- 2.28 microg x h/mL in diabetic rats vs. 18.02 +/- 3.45 microg x h/mL in normal rats). We also found lower apparent permeability coefficients of baicalin in the ileum of diabetic rats (8.43 x 10 (-6) +/- 2.40 x 10 (-6) cm/s in diabetic rats vs. 5.21 x 10 (-5) +/- 1.55 x 10 (-5) cm/s in normal rats). Further studies showed that the diabetic condition enhanced the hydrolysis of baicalin to baicalein in intestinal mucosal, accompanied by an increase of beta-glucuronidase activity. All these results suggested that the higher oral exposure of baicalin in diabetic rats did not result from the decreased hepatic metabolism or increased intestinal absorption of baicalin. The enhancement of intestinal beta-glucuronidase activity may partly account for the higher exposure of baicalin in diabetic rats after oral administration.

Protection against aflatoxin-B1-induced liver mutagenesis by Scutellaria baicalensis

We have measured the inhibition of the mutagenicity of the mycotoxin aflatoxin-B(1) in the liver of the rat by plant material of Scutellaria baicalensis, or Huang-qin. The addition of one percent dried Huang-qin to the feed of the animals reduced the mutant frequency of a subsequent administration of aflatoxin-B1 by approximately 60 and 77%, respectively, for two different batches of the plant material. The addition of Huang-qin also increased the expression of the gene for glutathione S-transferase A5 subunit by 2.5-3.0-fold, and decreased expression of P450 cytochrome 3A2 by 1.8-2.0-fold. The greater increase of the expression of the GST gene may result in the protection shown by Huang-qin. The sensitivity of the hepatic mitochondria to swelling, a measure of the mitochondrial permeability transition, is increased significantly in animals that are on a diet containing Huang-qin. This may lead to increased sensitivity to apoptosis on treatment with toxic compounds. The two batches of Huang-qin material show differences in both chemical composition and preventive potential. This study demonstrates how a combination of generating and analysis of plant varieties together with a mammalian assay for efficacy may improve the search for better plant-based prevention of cancer initiation.

Neuroprotective effect of oral S/B remedy (Scutellaria baicalensis Georgi and Bupleurum scorzonerifolfium Willd) on iron-induced neurodegeneration in the nigrostriatal dopaminergic system of rat brain

AIM OF THE STUDY

S/B remedy prepared from Scutellaria baicalensis Georgi and Bupleurum scorzonerifolfium Willd, two herbals of Xiao-Tsai-Hu-Tang or Sho-Saiko-To (TJ-9), contains active flavonoids. In this study, the protective effect of S/B remedy on iron-induced neurodegeneration was investigated in the nigrostriatal dopaminergic system of rat brain.

MATERIALS AND METHODS

The antioxidative activity of S/B remedy was studied using brain homogenates incubated with ferrous citrate (iron, 1M), S/B remedy, Trolox and melatonin. Furthermore, a Parkinsonian animal model by an intranigral infusion of iron in the anesthetized rats was employed to investigate the protective effect of S/B remedy in the nigrostriatal dopaminergic system.

RESULTS

Our in vitro studies showed that S/B remedy was more potent than melatonin and equal to trolox in inhibiting iron-induced lipid peroxidation of brain homogenates. Our in vivo studies found that oral administration of S/B remedy dose-dependently attenuated iron-elevated lipid peroxidation in the infused substantia nigra (SN) and iron-depleted dopamine levels in the ipsilateral striatum. Furthermore, iron-induced reductions in glutathione (GSH) content and increases in GSSG (oxidized GSH)/GSH ratio in the infused SN were inhibited in S/B remedy-treated rats. Systemic S/B remedy attenuated the iron-induced increases in heme-oxygenase-1 levels and α-synuclein aggregation in the infused SN. Moreover, S/B remedy reduced iron-induced apoptosis via attenuating mitochondrial and endoplasmic reticulum stress. In addition, S/B remedy was anti-inflammatory as indicated by the attenuation of iron-induced elevations in inducible nitric oxide synthase and cyclo-oxygenase II levels as well as glial fibrillary acidic protein (a biological marker of astrocytes) and ED-1 (a protein indicative of activated microglia) levels in the infused SN of S/B remedy-treated rats.

CONCLUSIONS

These findings suggest that oral administration of S/B remedy is protective against iron-induced neurodegeneration in the nigrostriatal dopaminergic system of rat brain. Therefore, S/B remedy may be therapeutically useful for the treatment of CNS neurodegenerative diseases.

Systematic Understanding of the Mechanism of Baicalin against Ischemic Stroke through a Network Pharmacology Approach

Ischemic stroke is accompanied by high mortality and morbidity rates. At present, there is no effective clinical treatment. Alternatively, traditional Chinese medicine has been widely used in China and Japan for the treatment of ischemic stroke. Baicalin is a flavonoid extracted from Scutellaria baicalensis that has been shown to be effective against ischemic stroke; however, its mechanism has not been fully elucidated. Based on network pharmacology, we explored the potential mechanism of baicalin on a system level. After obtaining baicalin structural information from the PubChem database, an approach combined with literature mining and PharmMapper prediction was used to uncover baicalin targets. Ischemic stroke-related targets were gathered with the help of DrugBank, Online Mendelian Inheritance in Man (OMIM), Genetic Association Database (GAD), and Therapeutic Target Database (TTD). Protein-protein interaction (PPI) networks were constructed through the Cytoscape plugin BisoGenet and analyzed by topological methods. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were carried out via the Database for Annotation, Visualization, and Integrated Discovery (DAVID) server. We obtained a total of 386 potential targets and 5 signaling pathways, including mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT), hypoxia-inducible factor-1 (HIF-1), nuclear factor kappa B (NF-κB), and forkhead box (FOXO) signaling pathways. GO analysis showed that these targets were associated with antiapoptosis, antioxidative stress, anti-inflammation, and other physiopathological processes that are involved in anti-ischemic stroke effects. In summary, the mechanism of baicalin against ischemic stroke involved multiple targets and signaling pathways. Our study provides a network pharmacology framework for future research on traditional Chinese medicine.

Shuang-Huang-Lian injection induces an immediate hypersensitivity reaction via C5a but not IgE

Among traditional Chinese medicine injections, intravenous Shuang-Huang-Lian (IV-SHL) has the highest incidence of injection-induced immediate hypersensitivity reactions (IHRs). The precise mechanisms of IV-SHL-induced IHRs remain ambiguous. In this study, we investigated the mechanisms of SHL injection (SHLI)-induced IHRs. Our data showed that serum total IgE and mouse mast cell protease 1 (MMCP1) levels were higher in the SHLI antiserum; however, these effects of SHLI disappeared in the antibiotic-treated mice. SHLI caused intraplantar vasopermeability and shock during the first local or systemic injection. SHLI-induced nonallergic IHRs were attributed to its intermediate fraction F2 (the extract of Lonicerae Japonicae Flos and Fructus forsythiae), and could be blocked by antagonists for histamine or C5a, rather than PAF or C3a. Eight constituents of F2 were able to directly activate C5 to promote local vasopermeability at the mg/mL level. In conclusion, SHLI-induced IHRs are not mediated by IgE. SHLI or its F2 can directly activate blood C5. Subsequently, C5a is likely to provoke histamine release from its effector cells (e.g., mast cells and basophils), indicating that histamine is a principal effector of IHRs induced by SHLI.