Effects of Scutellaria baicalensis on chronic cerebral hypoperfusion-induced memory impairments and chronic lipopolysaccharide infusion-induced memory impairments

Ethnopharmacological relevance

Extracts of the roots of Scutellaria baicalensis Georgi (Labiatae) have been widely used to relieve fever related to bacterial infection and inflammatory diseases in traditional Korean medicine and have been reported to be effective in brain diseases.These experiments were conducted to examine the effects of oral administration of Scutellaria baicalensis extracts on the rescue of memory impairments induced by chronic cerebral hypoperfusion or chronic lipopolysaccharide (LPS) infusion. In addition, the underlying mechanisms of these effects were investigated.

Materials and methods

In the first experiment, chronic cerebral hypoperfusion was induced in male Wister rats by bilateral common carotid artery occlusion (BCCAo). Daily administration of Scutellaria baicalensis extracts was started on 20 day after BCCAo and given for 40 days. A Morris water maze was then used to evaluate the status of the hippocampal-dependent spatial learning and hippocampal mitogen-activated protein kinase (MAPK) signaling was examined in control rats, rats with chronic cerebral hypoperfusion, and rats with chronic cerebral hypoperfusion that was administered Scutellaria baicalensis. In the second experiment, hippocampal microglial activation was induced by chronic infusions of LPS into the fourth ventricle of Fisher-344 rat brains. Daily administration of Scutellaria baicalensis extracts was started on 7 day after the surgery of LPS infusion and given for 32 days. Spatial memory and hippocampal microglial activation was then examined in control rats with an artificial cerebrospinal fluid infusion, rats with chronic LPS infusion, and rats with chronic LPS infusion that were administered Scutellaria baicalensis.

Results

Rats that received chronic cerebral hypoperfusion or chronic LPS infusion showed spatial memory impairments relative to their control rats; however, these symptoms were reduced by daily administration of Scutellaria baicalensis. Administration of Scutellaria baicalensis mitigated alterations of hippocampal MAPK signaling by chronic cerebral infusion and microglial activation by chronic LPS infusion.

Conclusions

These results indicate that Scutellaria baicalensis may possess therapeutic potential for the prevention of Alzheimer's disease and vascular dementia.     

Wogonin, an active ingredient of Chinese herb medicine Scutellaria baicalensis, inhibits the mobility and invasion of human gallbladder carcinoma GBC-SD cells by inducing the expression of maspin

Ethnopharmacological relevance

A traditional Chinese medicine Scutellaria baicalensis is prescribed for the treatment of a variety of inflammatory diseases and tumors in clinic in China. However, the detailed mechanism of anti-metastasis effect of wogonin, a main active ingredient of Scutellaria baicalensis, remains elusive.

Aim of the study

The present study was designed to investigate the action and mechanism of wogonin on the mobility and invasion of human gallbladder carcinoma GBC-SD cells.

Materials and methods

Viability, apoptosis, mRNA and protein expression of tumor cells were analyzed by MTT, Annexin V staining, real-time PCR and Western blot, respectively. The migration and invasion assay was used to evaluate the anti-metastasis effect of wogonin. Knockdown of maspin was performed by specific small interference RNA.

Results

Wogonin at the dose of 1-10 μM, which did not induce apoptosis, significantly inhibited the mobility and invasion activity of human gallbladder carcinoma GBC-SD cells. In addition, the expressions of matrix metalloproteinase (MMP)-2, MMP-9 and phosphorylated extracellular regulated protein kinase 1/2 (ERK1/2) but not phosphorylated Akt were dramatically suppressed by wogonin in a concentration-dependent manner. Furthermore, the metastasis suppressor maspin was confirmed as the downstream target of wogonin. Both maspin mRNA and protein were upregulated by wogonin. Interestingly, the knockdown of maspin resulted in almost completely blocking of wogonin-induced inhibition of MMP-2, MMP-9 and phosphorylated ERK1/2 as well as the mobility and invasion activity of GBC-SD cells.

Conclusions

These findings suggest that wogonin inhibits cell mobility and invasion by upregulating the metastasis suppressor maspin. Together, these data provide novel insights into the chemoprotective effect of wogonin, a main active ingredient of Chinese medicine Scutellaria baicalensis.     

Korean Scutellaria baicalensis water extract inhibits cell cycle G1/S transition by suppressing cyclin D1 expression and matrix-metalloproteinase-2 activity in human lung cancer cells

Aim of the study

Scutellaria baicalensis Georgi is a widely used medicinal herb in several Asian countries including Korea. The various medicinal properties attributed to Scutellaria baicalensis include anti-bacterial, anti-viral, anti-inflammatory and anti-cancer effects. The present study investigated the cytotoxicity of Scutellaria baicalensis water extract (SBWE) on A549 non-small-cell-lung cancer cells and the A549 expression of cyclin D1, cyclin-dependent kinase 4 (CDK4) and matrix metalloproteinase-2 (MMP-2), and the effects of SBWE on cell cycle progression, especially the G1/S phase, and on cell motility.

Materials and methods

SBWE cytotoxicity was assessed by a standard colorimetric assay utilizing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and expression of cyclin D1 and CDK4 protein in SBWE-treated A549 cells was assessed by Western blot analysis. Flow cytometry analysis was performed to determine the effect of SBWE on A549 cell cycle progression. A549 cell MMP-2 activity was examined by zymography. Cell motility and migration was assessed by a scratch wound healing assay.

Results

SBWE was not cytotoxic. The production of Cyclin D1, CDK4 and MMP-2 activity were significantly decreased in a SBWE dose-dependent manner, with maximum inhibition occurring at SBWE concentrations of 250 μg/ml and 500 μg/ml. SBWE inhibited cell cycle progression in the G1/S phase and significantly inhibited the motility of A549 cells.

Conclusions

Cyclin D1 protein may be associated with MMP-2 activity and cell motility. Thus, SBWE promotes a strong protective effect against MMP-2 mediated metastasis and cell proliferation through the down-regulation of cyclin D1. SBWE may be a useful chemotherapeutic agent for lung cancer.     

(2S)-naringenin from Typha angustata inhibits vascular smooth muscle cell proliferation via a G0/G1 arrest

Ethnopharmacological relevance

Typha angustata is used in traditional Chinese medicine for a variety of clinical disorders. Its pharmacological actions include beneficial effects on hyperlipidemia and myocardial infarction, as well as labor-inducing and antibacterial effects.

Aim of the study

We investigated the mechanism underlying the ability of (2S)-naringenin, an active compound from Typha angustata, to inhibit the proliferation of vascular smooth muscle cells (VSMCs).

Materials and methods

After measuring the antiproliferative effect of (2S)-naringenin on VSMC proliferation using cell proliferation and viability assays, the possible involvement of a signaling pathway associated with platelet-derived growth factor receptor β (PDGF-Rβ), extracellular signal regulated kinase 1/2 (ERK1/2), phosphatidylinositol 3-kinase (PI3K)-linked protein kinase B (Akt/PKB), or phospholipase C-γ1 (PLCγ1) was investigated by immunoblotting. Moreover, the effect of (2S)-naringenin on DNA synthesis and the cell cycle was examined using a [³H]-thymidine incorporation assay and flow cytometry.

Results

(2S)-Naringenin significantly inhibited PDGF-BB-induced VSMC proliferation in a concentration-dependent manner, but did not affect signaling pathways associated with PDGF-Rβ, Akt/PKB, ERK1/2, or PLCγ1. However, (2S)-naringenin suppressed DNA synthesis via a G₀/G₁ cell cycle arrest. Accordingly, the expression of cyclins D1 and E and cyclin-dependent kinases 2 and 4 was inhibited in a concentration-dependent manner; moreover, the phosphorylation of retinoblastoma protein was suppressed.

Conclusions

Our results show that (2S)-naringenin inhibited the PDGF-BB-induced proliferation of VSMCs via a G₀/G₁ arrest; thus, (2S)-naringenin may be valuable as a therapeutic agent for managing atherosclerosis and/or vascular restenosis.     

Baicalein, isolated from Scutellaria baicalensis, protects against endothelin-1-induced pulmonary artery smooth muscle cell proliferation via inhibition of TRPC1 channel expression

Ethnopharmacological relevance

We investigated the antiproliferative effects of baicalein, isolated from Scutellaria baicalensis (Huang-qin), on ET-1-mediated pulmonary artery smooth muscle cells (PASMCs) proliferation and the mechanisms underlying these effects.

Materials and methods

Intrapulmonary artery smooth muscle cells were isolated and cultured from female Sprague-Dawley rats and used during passages 3-6. The proliferation of PASMCs was quantified by cell counting and XTT assay. The protein expression of TRPC1 and PKCα were determined by western blotting. The cell cycle pattern was assayed by flow cytometry. The intracellular calcium concentrations ([Ca²⁺]_i) were measured using the fluorescent indicator fura-2-AM and flow cytometry.

Results

Baicalein (0.3-3 μM) inhibited PASMCs proliferation, promoted cell cycle progression, enhanced [Ca²⁺]_i levels, increased capacitative Ca²⁺ entry (CCE), upregulated the canonical transient receptor potential 1 (TRPC1) channel and membrane protein kinase Cα (PKCα) expression induced by ET-1 (0.1 μM). The PKC activator PMA (1 μM) reversed the inhibitory effects of baicalein on ET-1-induced upregulation of TRPC1 expression and S phase accumulation, while the PKC inhibitor chelerythrine (1 μM) potentiated baicalein-mediated G₂/M phase arrest and TRPC1 channel inhibition.

Conclusion

Our findings suggest that baicalein protects against ET-1-induced PASMCs proliferation via modulation of the PKC-mediated TRPC channel.     

Cortex Dictamni extract induces apoptosis of activated hepatic stellate cells via STAT1 and attenuates liver fibrosis in mice

Ethnopharmacological relevance

In traditional Chinese medicines, Cortex Dictamni is prescribed for the treatment of a variety of inflammatory diseases such as acute rheumatoid arthritis, skin inflammation and jaundice.

Aim of the study

This study was designed to investigate the effect of ethanol extract of Cortex Dictamni on treatment of hepatic fibrosis and its possible mechanisms.

Materials and methods

The in vivo effect of Cortex Dictamni extract (CDE) was evaluated by measuring histological changes and collagen content in CCl₄-indcued hepatic fibrosis mice. Viability, apoptosis and protein expression of hepatic stellate cells (HSC) were analyzed by MTT, Annexin V staining and Western blot respectively.

Results

CDE alleviated CCl₄-induced hepatic fibrosis in mice and showed a much stronger inhibition of cell viability in activated HSC cell line HSC-T6 than that in normal hepatocyte L02 cells. Furthermore, CDE induced apoptosis of HSC-T6 cells associated with increased expressions of cleaved PARP and cleaved caspase-3. Interestingly, CDE activated STAT1 in HSC-T6 cells and the effect of CDE on apoptosis of HSC-T6 cells could be neutralized using JAK/STAT1 signaling inhibitor AG490.

Conclusions

These findings suggest that CDE possesses anti-fibrosis activity with selectively induction of activated HSC apoptosis via activating STAT1, which might be a novel strategy for hepatic fibrosis therapy.     

Memory improvement in ibotenic acid induced model rats by extracts of Scutellaria baicalensis

Ethnopharmacological relevance

Scutellaria baicalensis Georgi (Labiatae) extracts have been used as traditional Korean medicine, to treat cerebral ischemia in addition to bacterial infection and inflammatory diseases.

Aim of the study

The improvement effect on learning and memory by the administration of Scutellaria baicalensis extracts was evaluated and the underlying mechanisms were investigated.

Materials and methods

Memory behavior was tested by the passive avoidance test and Y-maze test. We also investigated the cells expressing neuronal markers related to memory processes by immunofluorescence staining analysis in memory deficient animal model (Ibo model) rats and in hippocampal progenitor cells.

Results

We found neuronal cells immunoreactive to choline acetyltransferase (ChAT), a marker for cholinergic neurons were increased in the hippocampus, while cells producing GABA and glutamate were not after 30 mg/kg Scutellaria baicalensis administration. Futhermore, Scutellaria baicalensis extracts enhanced the survival of a hippocampal progenitor cell line, HiB5 and its differentiation to ChAT immunoreactive cells. The increased expression of memory related neurotransmitter, NMDA receptor and a reduction of activated microglia in the hippocampus were also observed in the Ibo model when administrated Scutellaria baicalensis extracts.

Conclusions

These results imply that Scutellaria baicalensis has significant neuroprotective effects in the Ibo model.     

Synergistic effects of baicalein with ciprofloxacin against NorA over-expressed methicillin-resistant Staphylococcus aureus (MRSA) and inhibition of MRSA pyruvate kinase

Ethnopharmacological relevance

Baicalein, the active constituent derived from Scutellaria baicalensis Georgi., has previously been shown to significantly restore the effectiveness of β-lactam antibiotics and tetracycline against methicillin-resistant Staphylococcus aureus (MRSA). With multiple therapeutic benefits, the antibacterial actions of baicalein may also be involved in overcoming other bacterial resistance mechanisms. The aim of the present study was to further investigate antibacterial activities of baicalein in association with various antibiotics against selected Staphylococcus aureus strains with known specific drug resistance mechanisms.

Material and methods

A panel of clinical MRSA strains was used for further confirmation of the antibacterial activities of baicalein. The effect of baicalein on inhibiting the enzymatic activity of a newly discovered MRSA-specific pyruvate kinase (PK), which is essential for Staphylococcus aureus growth and survival was also examined.

Results

In the checkerboard dilution test and time-kill assay, baicalein at 16 μg/ml could synergistically restore the antibacterial actions of ciprofloxacin against the NorA efflux pump overexpressed SA-1199B, but not with the poor NorA substrate, pefloxacin. Moreover, synergistic effects were observed when baicalein was combined with ciprofloxacin against 12 out of 20 clinical ciprofloxacin resistant strains. For MRSA PK studies, baicalein alone could inhibit the enzymatic activity of MRSA PK in a dose-dependent manner.

Conclusion

Our results demonstrated that baicalein could significantly reverse the ciprofloxacin resistance of MRSA possibly by inhibiting the NorA efflux pump in vitro. The inhibition of MRSA PK by baicalein could lead to a deficiency of ATP which might further contribute to the antibacterial actions of baicalein against MRSA.     

The absorption characterization effects and mechanism of Radix Angelicae dahuricae extracts on baicalin in Radix Scutellariae using in vivo and in vitro absorption models

Ethnopharmacological relevance

Angelicae Dahurica(Hoffm.)Benth.&Hook.f.ex Franch.&Sav combined with Scutellaria baicalensis Georgi. has been widely used as herb-pairs in traditional Chinese medicine (TCM) to treat migraine headache and cataract, but the underlying compatibility mechanism of the two herbs remains unknown.

Aim of study

In the present work, we investigated the additive or synergistic effects of absorption behavior of Radix Angelicae dahuricae extracts on baicalin, and the absorption-enhancing mechanism of Radix Angelicae dahuricae extracts on baicalin.

Materials and methods

Total coumarins (Cou) and volatile oil (VO), as the two main components of Radix Angelicae dahuricae, were extracted by supercritical fluid extraction (SFE) further treated with liquid-liquid separation method. The absorption behavior was investigated by applying the everted gut sac technique and in situ single-pass intestinal perfusion method.

Results and conclusions

The results showed that both the Cou and the VO could improve the intestinal absorption of baicalin in vivo, and had synergistic action the enhanced absorption of baicalin. Since verapamil did not affect the P_app and K_a of baicalin significantly, we concluded that the absorption of Baicalin could not be an active transportation in dependent of P-glycoprotein-Mediated efflux systems. Based on intestinal absorption of drug studying was one of the efficacious methods to clarify the compatibility of principles of herb-pairs. The everted gut sac technique and in situ single-pass intestinal perfusion technique model were the effective methods to study the absorption of drug, the application of the animal model to investigating the absorption of herb-drug interactions or other relevant research purposes is envisioned.     

Icaritin induces cell death in activated hepatic stellate cells through mitochondrial activated apoptosis and ameliorates the development of liver fibrosis in rats

Aim of the study

Icaritin is an active ingredient extracted from the plant Herba Epimedium Sagittatum (Sieb. et Zucc.) Maxim. The purpose of this study is to investigate the effects and mechanisms of icaritin-induced cell death in activated hepatic stellate cells (HSCs) and ameliorating the development of liver fibrosis in rats.

Materials and methods

: In vitro, icaritin-induced cell death rates in HSC-T6 (rat) and LX-2 (human) HSC lines as well as normal hepatocyte cell lines HL-7702 (L02) and WRL-68 were assayed by MTT method, and the apoptotic ratios were detected by both flow cytometry and the Annexin-V-FITC Apoptosis Detection Kit. A Whole Rat Genome Microarray Kit was used to identify expression of interest genes through fold-change screening. In vivo study, experimental liver fibrosis models were built by carbon tetrachloride (CCl₄) or common bile duct ligation (CBDL) in Wistar rats. Icaritin (1 mg/kg/day, three days a week) was administered by gastric gavage for four weeks (n = 6 per group). At the end of the study, serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) as well as the contents of hydroxyproline and collagen I in liver tissues were measured. Histopathological changes and the distribution of activated HSCs were observed in the liver tissues using hematoxyline-eosin (HE) staining and immunohistochemical staining for α-smooth muscle actin (α-SMA).

Results

Icaritin induced apoptosis in HSC-T6 and LX-2 in a concentration- and time-dependent manner with little toxicity to normal hepatocyte cell lines. The IC₅₀ of icaritin in HSC-T6 was 12.83 μM at 48 h. Apoptotic ratio of HSC-T6 treated with 24 μM icaritin was 20.19%, and the G2 phase of the cell cycle did not occur (P < 0.05). Gene analysis showed that icaritin up-regulated Bak-1, Bmf and Bax expression while significantly down-regulated Bcl-2 expression (vs. control group, P < 0.01). These results suggested that mitochondrial pathway played an important role in icaritin-induced apoptosis in activated HSCs. In vivo results showed that icaritin reduced the number of activated HSCs, and brought the elevated levels of AST, ALT, hydroxyproline and collagen I to normal or near normal values (vs. model group, P < 0.05).

Conclusions

Icaritin can induce cell death in activated HSCs through mitochondria-mediated apoptosis, ameliorate the progression of hepatic fibrosis in rats, and could be a promising drug for treating liver fibrosis.     

Lipoxygenase inhibitory activity of crude bark extracts and isolated compounds from Commiphora berryi

Ethnopharmacological relevance

Commiphora berryi is traditionally used for the treatment of cold and fever as well as for wound healing in the southern parts of India.

Aim of study

The present study was designed to investigate in vitro soybean lipoxygenase inhibitory activity of crude extracts and compounds isolated from Commiphora berryi.

Materials and methods

The bark of Commiphora berryi was extracted with different organic solvents and subjected to chromatographic separation for isolation of bioactive compounds. Structures of isolated compounds were elucidated by spectroscopic methods. The anti-inflammatory activity of bark extracts and bioactive compounds were assessed by in vitro soybean lipoxygenase (SBL) assay.

Results

3β-Hydroxyglutin-5-ene (1), friedelin (2), cycloeucaneol (3) nimbiol (4), sugiol (5), surianol (6), daucosterol (7) and ursolic acid (8) were isolated from crude bark extracts of the Commiphora berryi. The structure of nimbiol (4) was also confirmed by single crystal X-ray analysis. The petroleum ether, methanol, chloroform and ethyl acetate extracts of bark of Commiphora berryi showed SBL inhibitory activity with the IC₅₀ values of 15.3, 54.2, 71.5 and 87.8 μg/ml respectively. Among all the isolates, friedelin (2) showed significant SBL inhibitory activity with IC₅₀ 35.8 μM.

Conclusion

The overall results provide evidence that the studied plant might be a potential source of anti-inflammatory agents.     

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 2 h 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.     

Constituents isolated from Cordyceps militaris suppress enhanced inflammatory mediator's production and human cancer cell proliferation

Aim of the study

The purpose of this study is to isolate the pure compounds from the extracts of Cordyceps militaris obtained through solid-state cultivation process, and evaluate their anti-inflammatory and anticancer properties.

Materials and methods

Silica gel column chromatographic purification of Cordyceps militaris extracts resulted in the isolation of 10 pure compounds (1-10). The compounds 1-10 were examined for their growth inhibitory properties against nitric oxide (NO), tumor necrosis factor (TNF)-α and interleukin (IL)-12 enhanced production from LPS/IFN-γ-stimulated macrophages. Additionally, the anti-proliferation effects of 1-10 on human cancer cell lines, colon (colon 205), prostate (PC-3), and hepatoma (HepG2) cells were also analyzed.

Results

Compound 8 displayed potent growth inhibition on NO, TNF-α and IL-12 production with an IC₅₀ value of 7.5, 6.3, and 7.6 μg/ml, respectively. A similar inhibitory trend on these inflammatory mediators was observed for 3, 7, 9 and 10 with an IC₅₀ values ranging from 10.8 to 17.2 μg/ml. On the other hand, compounds 3 and 8 were potent anti-proliferative agents with an IC₅₀ value of 35.6 and 32.6 μg/ml toward PC-3 and colon 205 cell lines, respectively. The compounds 1 and 2 showed potent anti-proliferation in PC-3 and colon 205 cells, while only 3 displayed such effect in HepG2 cells.

Conclusion

The present study provides scientific supporting information for the ethnopharmacological use of Cordyceps militaris as an anti-inflammatory and anticancer agent.     

Gastrodia elata prevents huntingtin aggregations through activation of the adenosine A₂A receptor and ubiquitin proteasome system

Ethnopharmacological relevance

Gastrodia elata Blume (Fam. Orchidaceae) is a traditional Chinese herbal medicine for treating headaches, dizziness, tetanus, epilepsy, and numbness of the limbs, which suggests that it has neuroprotective effect.

Aim of the study

To validate the neuroprotection of Gastrodia elata in preventing neurodegenerations, such as Huntington's disease (HD).

Materials and methods

MTT assay was used to validate the protection of Gastrodia elata. In pheochromocytoma (PC12) cell. Transient transfection of mutant huntingtin (Htt) in PC12 cell was used as an in vitro model of HD. Filter retardation assay was used to measure Htt-induced protein aggregations. Proteasome activity was monitored by transfection of pZsProSensor-1 and imaged by a confocal laser scanning microscope.

Results

This protection of Gastrodia elata could be blocked by an A_2A-R antagonist and a protein kinase A (PKA) inhibitor, indicating an A_2A-R signaling event. Gastrodia elata could reverse mutant Htt-induced protein aggregations and proteasome de-activation through A_2A-R signaling. In addition, activation of PKA tended to activate proteasome activity and reduce mutant Htt protein aggregations. The proteasome inhibitor, MG 132, blocked Gastrodia elata-mediated suppression of mutant Htt aggregations.

Conclusion

Gastrodia elata prevented mutant Htt aggregations and increased proteasomal activity by targeting the A_2A-R through PKA-dependent pathway.     

Simulated gastrointestinal tract metabolism and pharmacological activities of water extract of Scutellaria baicalensis roots

Ethnopharmacological relevance

.

Scutellaria baicalensis

Georgi (Labiatae) is a well-known traditional Chinese medicine to treat inflammation, cardiovascular diseases, respiratory and gastrointestinal infections, etc. The present study was to understand the metabolism of the root of Scutellaria baicalensis (a.k.a. Huangqin in Chinese) in the gastrointestinal tract and the correlation between the metabolites and their respective pharmacological activities.

Materials and methods

The water extract of the root of Scutellaria baicalensis (WESB) was incubated with simulated gastric and intestinal juices, and human fecal microflora for 24 h at 37 °C. The HPLC–DAD analysis was used to monitor the in vitro metabolic process and identify its metabolites by comparing their absorption spectrum and retention time with those of chemical references. The in vitro anticomplementary and antimicrobial activity was evaluated with hemolysis assay, agar disc-diffusion method and MIC value, respectively.

Results

Main constituents of WESB remain unchanged during the incubation with simulated gastric juice (pH=1.5) and intestinal juice (pH=6.8), whereas four flavones, baicalin, wogonoside, oroxyloside and norwogonoside were metabolized into their respective aglycons by human intestinal bacteria. All four metabolites were demonstrated to have higher anticomplementary and antimicrobial activity than those of WESB. The anticomplementary active metabolites were identified to be baicalein, oroxylin A and norwogonin, among them, norwogonin is the most active compound.

Conclusion

The presence of intestinal bacteria is demonstrated to play an important role in the gastrointestinal metabolism of WESB, and the pharmacological effects of Scutellaria baicalensis may be dependent on the intestinal bacteria metabolism.     

Paeonia lactiflora Pall inhibits bladder cancer growth involving phosphorylation of Chk2 in vitro and in vivo

Ethnopharmacological relevance

Extracts of Paeonia lactiflora Pall (RPA), a traditional Chinese medicines has been shown to treat cancers.

Aim of the study

The purpose of this study is to evaluate the anticancer effect of RPA in urinary bladder carcinoma in vitro and in vivo.

Materials and methods

The cell viability was analyzed with DAPI. Flow cytometry and Western blot were used to study the apoptosis and cell cycle related mechanism. A rat model of bladder cancer was induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (OH-BBN). Tumors were analyzed with immunohistochemical analysis.

Results

Our data suggested that RPA inhibits growth of bladder cancer via induction of apoptosis and cell cycle arrest. Treatment of TSGH-8301 cells with RPA resulted in G2-M phase arrest that was associated with a marked decline in protein levels of cdc2, cyclin B1, cell division cycle 25B (Cdc25B) and Cdc25 C. We also reported that RPA-mediated growth inhibition of TSGH-8301 cells was correlated with activation of checkpoint kinase 2 (Chk2). Herein, we further evaluated urinary bladder cancer using a model of bladder cancer induced by OH-BBN. Analysis of tumors from RPA-treated rats showed significant decrease in the expression of Bcl2, cyclin D1, and PCNA, and increase in the expression of p-Chk2 (Thr-68), Bax, and Cip1/p21.

Conclusion

Our data provide the experimental evidence that RPA could modulate apoptosis in models of bladder cancer.     

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, 1 M), 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.