[Influence of Erigeron breviscapus on the expression of collagen type I , MMP1 and TIMP1 of MRC-5 cells under hypoxia]

OBJECTIVE

Study the influence of Erigeron breviscapus on collagen type I, matrix metalloproteinase1 (MMP1) and tissue inhibitor of metalloproteinase1(TIMP1) in human embryo lung fibroblast MRC-5 under hypoxia.

METHODS

MRC-5 cultured in vitro were individed into 4 groups, including normoxia control, hypoxia, hypoxia and staurosporine (SP), hypoxia and erigeron breviscapus. The expression of hypoxia-inducible factor-1 alpha (HIF-1alpha), pro-collal and phospho-smad2 (p-smad2) were evaluated by Western blot. The level of collagen type I, MMP1 and TIMP1 in supernatant fluid were detected by ELISA.

RESULTS

Expressed pro-collalpha1, p-smad2 in MRC-5 cells under nomoxia were detected, but not HIF-lalpha. A low level of collagen type I, MMP1 and TIMP1 was also detected in the cell supernatant. In nomoxia secreted pro-collalpha1, p-smad2, collagen type I , MMP1 and TIMP1, hardly secreted HIF-lalpha. Under hypoxia, the expression of all of them was increased when compared with those of under nomoxia condition (P < 0.05). MMP1 expression was significantly further upregluted by pre-cubation with SP in hypoxia, however collagen type I, TIMP1 in supernatant fluid and pro-collalpha1, p-smad2 in cells were inhibited (P < 0.05, vs. hypoxia group). Treated with Erigeron breviscapus (12. 5 microg/mL, 50 microg/mL) under hypoxia condition, significantly reduced expression of pro-collalpha1, p-smad2, HIF-1alpha in MRC-5 cells and collagen type I, MMP1, TIMP1 in supernatant fluid were observed (P < 0.05, vs. hypoxia).

CONCLUSION

Erigeron breviscapus can decrase the expression of HIF-1alpha of MRC-5 cells under hypoxia condition by inhibit the expression of collagen type I and TIMP1 partly through the Smad2 signaling pathways.

[Optimize the preparation process of Erigeron breviscapus sustained-release pellets based on artificial neural network and particle swarm optimization algorithm]

OBJECTIVE

To optimize the preparation process of Erigeron breviscapus sustained-release pellets.

METHODS

A mathematical model of relationship between the independent variables and dependent variable of the preparation process of Erigeron breviscapus sustained-release pellets was established by using back-propagation (BP) artificial neural networks (ANN), and the preparation process parameters were optimized with particle swarm optimization (PSO) algorithm.

RESULTS

The pellets prepared according to the optimized preparation process parameters had significant effect of sustained-releasing. Drug release from the pellets was controlled by both diffusion and matrix corrosion.

CONCLUSION

Combining BP ANN modeling with PSO algorithm provides an effective way to solve the multi-dimensional optimization problem of complicated nonlinear systems in pharmaceutical technology.

In-line monitoring of extraction process of scutellarein from Erigeron breviscapus (vant.) Hand-Mazz based on qualitative and quantitative uses of near-infrared spectroscopy

The application of near-infrared (NIR) spectroscopy for in-line monitoring of extraction process of scutellarein from Erigeron breviscapus (vant.) Hand-Mazz was investigated. For NIR measurements, two fiber optic probes designed to transmit NIR radiation through a 2 mm pathlength flow cell were utilized to collect spectra in real-time. High performance liquid chromatography (HPLC) was used as a reference method to determine scutellarein in extract solution. Partial least squares regression (PLSR) calibration model of Savitzky-Golay smoothing NIR spectra in the 5450-10,000 cm(-1) region gave satisfactory predictive results for scutellarein. The results showed that the correlation coefficients of calibration and cross validation were 0.9967 and 0.9811, respectively, and the root mean square error of calibration and cross validation were 0.044 and 0.105, respectively. Furthermore, both the moving block standard deviation (MBSD) method and conformity test were used to identify the end point of extraction process, providing real-time data and instant feedback about the extraction course. The results obtained in this study indicated that the NIR spectroscopy technique provides an efficient and environmentally friendly approach for fast determination of scutellarein and end point control of extraction process.

Effects of scutellarin on MUC5AC mucin production induced by human neutrophil elastase or interleukin 13 on airway epithelial cells

Scutellarin is a flavonoid extracted from a traditional Chinese herb, Erigeron breviscapus. The present study investigated the effect of scutellarin on MUC5AC mucin production and the possible mechanism. Human bronchial epithelial 16 (HBE16) cells were pretreated with scutellarin for 60 min, and then exposed to human neutrophil elastase (HNE) or interleukin (IL)-13 for 12 hr. RT-PCR and ELISA were performed to measure the amount of MUC5AC mucin production. The results showed that scutellarin inhibited MUC5AC expression both in mRNA and protein level induced by HNE in a concentration-dependent manner. However, scutellarin failed to inhibit MUC5AC mucin production induced by IL-13. To investigate the intracellular mechanisms associated with the effect of scutellarin on MUC5AC mucin production, western blotting was carried out to examine the phosphorylation of protein kinase C (PKC), signal transducer and activator of transcription 6 (STAT6) and extracellular signal-regulated kinase 1/2 (ERK1/2). The phosphorylation of PKC and ERK1/2 was attenuated after treatment with scutellarin, whereas STAT6 was not significantly affected. Therefore, it is suggested that scutellarin down-regulates MUC5AC mucin production on HBE16 cells via ERK-dependent and PKC-dependent pathways.

[Chemical constituents from herbs of Erigeron breviscapus]

OBJECTIVE

To study the chemical constituents from herbs of Erigeron breviscapus.

METHOD

The compounds were isolated and purified by various chromatographic techniques. Their structures were identified on the basis of physicochemical properties and spectral analysis.

RESULT

Twelve compounds were isolated and structurally identified as quercetin-3-O-beta-D-glucoside (1), 5, 7-dihydroxychromone (2), 3-O-caffeoyl-gamma-quinide (3), naringenin (4), 3, 5-di-O-caffeoylquinic acid (5), 3,4-di-O-caffeoylquinic acid (6), 4, 5-di-O-caffeoylquinic acid (7), 1,3-di-O-caffeoylquinic acid (8), 1, 5-di-O-caffeoylquinic acid (9), 3-O-caffeoylquinic acid (10), 4-O-caffeoylquinic acid (11) and chlorogenic acid (12).

CONCLUSION

Compounds 1-4 were isolated from this plant for the first time.

[Effects of Erigeron breviscapus injection on TNF-alpha, PAI-1 and tPA in rats with acute myocardial infarction]

OBJECTIVE

To research the effects of Erigeron breviscapus injection (EBI) on TNF-alpha, PAI-1 and tPA in rats with acute myocardial infarction.

METHODS

Models of acute myocardial infarction (AMI)were produced by ligation of left anterior descending coronary artery, then rats were randomly divided into control and experimental groups, then respectively gavaged NS, and the low, middle and high dosage of EBI for one week. The cardiac function index and the expression of TNF-alpha, tPA and PAI-1 were measured.

RESULTS

Compared with the NS group, the cardiac function LVEDP, MAP, LVPmax, +/- dp/dt of AMI rat was improved by EBI in all dosage range, and the expression of TNF-alpha and PAI-1, LVEDP were decreased (P < 0.05), the expression of tPA, MAP, LVPmax and +/- dp/dt were increased obviously (P < 0.05) and had a dose-effect relationship.

CONCLUSION

EBI can inhibit the expression of TNF-alpha and PAI-1, increase the expression of tPA,which can prevent the ongoing thrombopoiesis after AMI and improve the cardiac function. This maybe attributes to the inhibition of the overexpression of TNF-alpha.

Rapid screening and identification of caffeic acid and its esters in Erigeron breviscapus by ultra-performance liquid chromatography/tandem mass spectrometry

Caffeic acid and its esters (CAEs) are widely distributed in the plant kingdom and have been reported to elicit a wide range of exceptional biological activities. Present methods for screening and characterization of CAEs normally need the use of liquid chromatography diode-array detection/multistage mass spectrometry (LC-DAD/MS(n)). In this report, a rapid and efficient method coupling ultra-performance liquid chromatography (UPLC) with fragment-targeted multi-reaction monitoring (MRM) has been developed for screening CAEs in a crude extract of Erigeron breviscapus, while a UPLC/quasi-MS(n) method has been applied in the structural identification of these compounds. Furthermore, a simple quasi-UPLC/MS/MS method based on in-source collision-induced dissociation (CID) has been proposed for rapid identification of the CAEs. As a result, a total of more than 34 CAEs were detected and their structures characterized. Nine of them were reported from E. breviscapus for the first time. Applications of these strategies in the chemical investigation of an injection of E. breviscapus resulted in the identifications of 16 CAEs. These strategies, if appropriate modifications are made, will be very useful in screening and characterization not only of CAEs, but of other structural types of compounds in various complex matrices.

[Study on the extraction of breviscapine from Erigeron breviscapus with ultrasonic wave technology optimized by central composite design-response surface method]

OBJECTIVE

To evaluate the effectiveness of ultrasound-assisted extraction and establish the optimized extraction conditions of breviscapine from Erigeron breviscapus.

METHODS

On the basis of the single factor and according to the central composite design principles (CCD), the response surface method (RSM) with 3 factors and 3 levels was adopted and the independent variables were ultrasonic wave extracting time, ethanol concentration, and the ratio of solvent volume to Erigeron breviscapus mass, breviscapine extraction yield determinated by HPLC was used as response value.

RESULTS

Ultrasonic wave extracting time of 24.5 min, ethanol concentration of 74.7% and the ratio of solvent volume to Erigeron breviscapus mass of 19.8 (mL/g) were selected as optimum conditions. Regression coefficients of binomial fitting complex model was 0. 9549 and the predicted breviscapine extraction yield was 0.641%, while the actual extraction yield was 0.632% (n = 5), with relative error of -1.14%.

CONCLUSION

This study confirms the efficiency of ultrasound-assisted extraction as a simple, inexpensive and effective method to improve the extraction of breviscapine from Erigeron breviscapus. The observed and predicted values are close to each other, which proves that the optimization of supersonic extraction process of breviscapine from Erigeron breviscapus by CCD-RSM is reasonable and successful.

GC-MS analysis, antibacterial activity and genotoxic property of Erigeron mucronatus essential oil

GC-MS analysis of the hydrodistilled oil of Erigeron mucronatus DC was carried out, after the separation of a crystalline compound, lachnophyllum cumulene. Twenty-four components were identified. The oil contained 59.6% sesquiterpenoids, 16.1% monoterpenoids and 24.3% poly-acetylenic esters. Among the mono and sesquiterpenoids, limonene (10.3%) and caryophyllenes (11.4%) were the major constituents. The essential oil also revealed the unusual presence of both cis (8.3%) and trans (1.1%) methyl lachnophyllum esters. Seasonal variation in the yield of E. mucronatus oil was observed. The yield varied from 0.49 to 0.58%, being highest during the rainy season. Antimicrobial activity was assessed using a method based on zones of inhibition; the oil exhibited maximum anti- bacterial activity against both Staphylococcus aureus and Escherichia coli, but moderate activity against Pseudomonas aeruginosa. Genotoxicity of the oil was determined in AB blood serum at different concentrations and hours of exposure. The antibacterial activity of the oil and its insignificant genotoxicity at low concentrations make the oil a good candidate as a curative agent.

[Formula screening and optimizing for the dispersible tablets of breviscapine by orthogonal experiment]

OBJECTIVE

To establish a suitable formulation for the dispersible tablets of brevisicapine.

METHODS

To prepare and optimize the breviscapine dispersible tablets by orthogonal experiment design using disintegration time as the index. The quality of breviscapine dispersible tablets was evaluated by the initial stability test.

RESULTS

The disintegration time of optimized prescription formulation was 89 s. L-HPC and CMS-Na were used by combining exterior and interior and the dissolution percent in vitro was obviously superior to the conventional tablets, and the quality of the dispersible tablets was very good in stability test.

CONCLUSION

The formulation screened out for the dispersible tablets of breviscapine is reasonable, stable and suitable for the production on a large scale.

[FTIR spectra-principal component analysis of Erigeron breviscapus and Erigeron multiradiatus from different areas]

Erigeron breviscapus and erigeron multiradiatus, belonging to compositae, have been widely used as "meiduoluomi" in traditional Tibetan medicine for treatment of heat-clearing and detoxicating. However, it is difficult to distinguish them because of similarity of morphology. Therefore, the chemotaxonomy method was established. FTIR fingerprint spectra of E. breviscapus and E. multiradiatus samples from 13 geographical origins were studied. The results demonstrated that they could be divided into 2 classes with principal component analysis (PCA). The classification was well correlated to their gene, geographical origins and weather. In the same class, the chemical components are similar to each other, which can be considered as the criterion for evaluating their quality. The results showed that their infrared spectra characteristic of the same species was similar in the range of 4 000-450 cm(-1), but varied significantly for different species. The method is rapid and simple, and could be applied to evaluate the quality of this traditional medicine.

Estrogenic and neuroprotective properties of scutellarin from Erigeron breviscapus: a drug against postmenopausal symptoms and Alzheimer's disease

Besides the classical hormonal effect, estrogen possesses neuroprotective effects in the brain, which leads to the searching of novel treatments for neurodegenerative diseases such as Alzheimer's disease. Scutellarin is a major flavone derived from Herba Erigerontis, a Chinese medicine derived from Erigeron breviscapus, which has been shown here to possess both estrogenic and neuroprotective properties. Scutellarin showed the estrogenic effects by activating the estrogen responsive elements and phosphorylation of estrogen receptor alpha in cultured MCF-7 cells: the activation was in a dose-dependent manner. On the other hand, scutellarin inhibited the aggregation of beta-amyloid in vitro, and prevented the cell death mediated by beta-amyloid when applied to cultured neuronal PC12 cells. These results therefore suggested that Herba Erigerontis and its component scutellarin might have therapeutic effects against postmenopausal symptoms and Alzheimer's disease.

[Effects of doubled CO2 concentration on Erigeron breviscapus growth and its active constituent accumulation]

With medicinal plant Erigeron breviscapus as test material, its biomass and the contents and yields of scutellarin and caffeate were monitored under doubled (800 +/- 100) micromol x mol(-1) and natural (400 +/- 25) micromol x mol(-1) CO2 concentration. Comparing with those under natural CO2 concentration, the biomass of E. breviscapus under doubled CO2 concentration increased by 22%, the contents of scutellarin and caffeate increased by 23% and 26%, and the yields of these two constituents increased by 37.6% and 45.3%, respectively. Different organs had different responses in their biomass and active constituent contents to the elevated CO2 concentration. Under doubled CO2 concentration, the plant N content decreased by 47.2% and was negatively correlated with active constituent contents, being accorded well to the C/N balance hypothesis, and the biomass was positively correlated with the active constituent contents while no trade-off was observed between plant growth and secondary metabolism, suggesting that rational application of CO2 could improve the yield and quality of E. breviscapus.

[Comparison of the distribution of breviscapine in the brain by different administration routes]

By comparing the drug distribution of breviscapine administered intranasally, orally and intrgvenous injected in rats' brain. After 0.4 mg x kg(-1) breviscapine was given by tail vein, intranasal and gastric perfusion administration to SD rats, cerebrospinal fluid was obtained by erebellomedllery cisternal puncture at different times. 125I labeling was used to determine the drug content of cerebrospinal fluid, cerebrum, cerebellum, medulla oblongata, olfactory region, olfactory bulb and blood in rats. AUCs were calculated by trapezoidal rule. The results showed that AUCs(0-240 min) (microg x min x g(-1)) of brain tissues were 11.686 +/- 1.919, 5.676 +/- 1.025, 7.989 +/- 0.925, 7.956 +/- 1.159, 17.465 +/- 2.136, 24.2 +/- 2.906 and 78.51 +/- 12.05, respectively, in the intranasal administration group; while those in the tail vein administration groups were 6.79 +/- 0.661, 6.251 +/- 0.40, 10.805 +/- 1.161, 9.146 +/- 1.04, 9.892 +/- 1.532, 7.871 +/- 0.842 and 173.91 +/- 10.02; and oral administration group were 0.868 +/- 0.167, 1.708 +/- 0.266, 2.867 +/- 0.725, 2.067 +/- 0.313, 1.361 +/- 0.308, 1.206 +/- 0.255 and 45.2 +/- 7.52, respectively. AUCs(0-240 min) of the brain tissues after oral, tail vein and intranasal administration were 22.29%, 29.18%, 95.49% of that of blood, respectively, it means that the absorption rate and drug distribution in the brain tissues after intranasal administration were higher than those of oral and tail vein administration. It is worth to investigate further the pharmacodynamic relationship.

[Effect of water stress on content of active constituents in Erigeron breviscaps]

OBJECTIVE

To study the effect of water stress on the content of scutellarin and caffeate in Erigeron breviscaps.

METHOD

Fv/Fm, N content, as well as the content of scutellarin and caffeate under three water grads were measured.

RESULT AND CONCLUSION

Fv/Fm of the plant decreased significantly in 8% and 23% water treatment, that proved drought and waterlogging occurred. Under the two conditions, the contents of N were lower but the contents of active constituents were higher than those under 15% treatment. The results support the carbon-nutrient balance hypothesis and the "stress effect hypothesis" for the formation of geo-herbs.

Breviscapine improves functions of spatial learning and memory of focal cerebral ischemia rats

OBJECTIVE

To investigate the effects of breviscapine on the functions of spatial learning and memory of focal cerebral ischemia rats.

METHODS

Rots withl the left middle cerebral artery occluded were made by an intraluminal filament. Then breviscapine (20 mg/kg,40 mg/kg) in experimental group and 10% glucose in control group were administered intraperitoneally once a day for 2 weeks, and the Morris water maze tasks were carried out for 5 days.

RESULTS

Compared with sham-operation group,the animals of ischemia-control group exhibited seriously impaired spatial learning and memory in both place navigation test and spatial probe test. In the place navigation test, the mean value of escape latency in breviscapine group was significantly shorter than that in ischemia control group (P < 0.01 for lower-dose and P < 0.05 for higher-dose breviscapine group, respectively). In the spatial probe test,compared with sham-operation (P < 0.01) and breviscapine group (P < 0.01), the rats of ischemia-control group spent more time in the no-former platform quadrant, and showed reduced frequency of crossing former platform site significantly. The numbers of neurons with Nissl staining and choline acetyltransferase (ChAT) immunopositive neurons in ipssilateral cortex in the breviscapine group were significantly more than those in the ischemia-control group (P < 0.01). In hippocampus, the numbers of neurons with Nissl staining and ChAT immunopositive neurons in the stratum pyramidale of CA area were similar among the groups.

CONCLUSION

These results indicate that breviscapine can improve the functions of spatial learning and memory of focal cerebral ischemia rats and the protection against the loss of ChAT immunopositive neuron in new cortex may be involved in its mechanisms.

[The effect of polyamidoamine (PAMAM) dendrimers on the solubility and pharmacokinetics of breviscapine]

To study the solubilization of breviscapine with polyamidoamine (PAMAM) dendrimers and probe the solubilizing mechanism and investigate the influence of PAMAM dendrimers on the pharmacokinetics of breviscapine, the solubilization of breviscapine by PAMAM dendrimers of generations G1, G1.5, G2 and G2.5 with different concentrations were determined and compared in different pH conditions. Twelve rats randomized into 2 groups were separately orally administered breviscapine and breviscapine combining with PAMAM. Drug in plasma was extracted and determined with HPLC. In pH condition lower than 7.0, the solubilization of breviscapine by PAMAM dendrimers enhanced as the generation and concentration of PAMAM dendrimers as well as the pH increased. Its solubilizing mechanism involves an electrostatic interaction between the carboxyl group of breviscapine and the primary amines and tertiary amines of PAMAM dendrimers. The pharmacokinetics parameters Cmax and AUC0-8 h of breviscapine were (119.65 +/- 9.36) ng x mL(-1) and (370.09 +/- 63.08) ng x h x mL(-1). For breviscapine combined with PAMAM dendrimers, the Cmax and AUC0-8 h were (518.17 +/- 17.07) ng x mL(-1) and (1,219.47 +/- 201.87) ng x h x mL(-1), respectively. There were significant differences of AUC0-8 h between breviscapine and breviscapine combined with PAMAM dendrimers (P < 0.01). PAMAM dendrimers can greatly increase the solubility of breviscapine in water and can improve the oral bioavailability of breviscapine significantly.

[Study on optimal harvest time of Erigeron breviscapus]

OBJECTIVE

To ascertain the optimal harvest time of Erigeron breviscapus.

METHOD

The dry matter weight accumulation of different organs in growth process and contents of scutellarin and coffeic acid ester in whole plant of E. breviscapus were determined.

RESULT

The number of leaves per plant, the dried weight of single leaf and dry matter weight of whole plant and different organs reached the highest after seedling 130-140 d. The content of scutellarin gradually decreased with growth period, and sharply decreased after seedling 140 d. The content of coffeic acid ester varied irregularly with growth period.

CONCLUSION

The optimal harvest time of E. breviscapus is in early bloom period after seedling 130 d.

Anti-inflammatory activity of the extracts and fractions from Erigeron multiradiatus through bioassay-guided procedures

ETHNOPHARMACOLOGICAL RELEVANCE

Erigeron multiradiatus (Lindl.) Benth., an herb that grows in the alpine and subalpine meadow of Qinghai-Tibet plateau, has been widely used as a folk remedy by the native people for treatment of various inflammatory ailments.

AIM OF THE STUDY

In order to isolate and identify the active components of Erigeron multiradiatus for anti-inflammatory activity, a preliminary phytochemical study and a bioassay-guided fractionation and purification process was performed.

MATERIAL AND METHODS

The dry whole plant Erigeron multiradiatus was extracted with 50% ethanol and then separated into CHCl(3), n-BuOH, and aqueous fractions. The anti-inflammatory activities of each fraction were investigated using two in vivo inflammation models.

RESULTS

These results exhibited varying degrees of anti-inflammatory activities and the n-BuOH fraction showed the strongest anti-inflammatory activities. The n-BuOH fraction was then subjected to separation and purification using macroporous resins column chromatography and Sephadex LH-20 leading to two flavonoids glucuronides identified as scutellarein-7-O-beta-glucuronide and apigenin-7-O-beta-glucuronide. Furthermore, LC-MS/MS identification and quantification of isolated compounds were also performed.

CONCLUSION

Scutellarein-7-O-beta-glucuronide and apigenin-7-O-beta-glucuronide were considered as major components and principally responsible for the anti-inflammatory activity of Erigeron multiradiatus. Thus the results of our study provide a scientific basis for the utilization of Erigeron multiradiatus in traditional Tibetan medicine.

[Studies on the constituents from the herba of Erigeron acer]

OBJECTIVE

To investigate the chemical constituents of the aerial part of Erigeron acer.

METHODS

The chemical constituents were isolated by various columns and thin layer chromatographic methods. The structures were identified by spectral data.

RESULTS

Five compounds were isolated and identified as alpha-amyrin (1), beta-amyrin (2), caffeic acid (3), quercetin (4), 4'-hydroxywogonin-7-O-beta-D-glucuronic acid glycoside (5).

CONCLUSION

The five compounds are obtained from this plant for the first time. The signals of 13C-NMR of the compound(5) are reassigned by means of DEPT, HMQC, HMBC, the signals of 1H-NMR of 2" - 5"-H of the glucuronic acid moiety are assigned by means of HMBC, HMQC, 1H-1H COSY for the first time.

Erigeroflavanone, a flavanone derivative from the flowers of Erigeron annuus with protein glycation and aldose reductase inhibitory activity

A novel 2,3-dioxygenated flavanone, erigeroflavanone ( 1), as well as eight known flavonoids and two known gamma-pyranone derivatives, were isolated from an ethyl acetate-soluble extract of the flowers of Erigeron annuus. The structure of compound 1 was elucidated by interpretation of spectroscopic data. All of the isolates were subjected to in vitro bioassays to evaluate their inhibitory activity against advanced glycation end products formation and rat lens aldose reductase.

[Effects of erigeron injection on renal interstitial fibrosis in rats]

OBJECTIVE

To investigate the effect and mechanism of Erigeron Injection (EI) on renal interstitial fibrosis in rats.

METHODS

Unilateral ureteral obstruction (UUO) model rats were taken as the subject of study. Thirty-six Sprague-Dawley rats were randomly divided into the control group (A), the UUO model group (B) and the treatment group (C) treated with intraperitoneal injection of EI 5 mL/kg per day from 24 h before to 9 days after the operation. On the 10th day of UUO, rats were killed and their kidneys were processed to paraffin sections with HE, PAS and picro-sirius-red staining. The pathological change of renal tubular interstitial tissue and relative cortical/interstitial volume (C/I) as well as the relative content of collagen (RC) were observed by light microscope. The expression of transforming growth factor beta1 (TGF-beta1), alpha-smooth muscle actin (alpha-SMA) and collagen I in the renal mesenchyma were examined by immunohistochemistry.

RESULTS

Marked renal interstitial fibrosis changes were found in Group B and C, but the changes were milder in Group C. C/I and RC were higher in Groups B and C as compared with those in Group A (P < 0.01), but they were much lower in Group C than in Group B (P < 0.01). The expression of TGF-beta1, alpha-SMA and collagen I were higher in Group B and C than those in Group A (P < 0.05), but they were lower in Group C than in Group B (P < 0.05).

CONCLUSION

EI could ameliorate renal interstitial fibrosis in rats, which might be partially realized by down-regulating the expression of TGF-beta1 to prevent the renal epithelial cell differentiation and reducing the synthesis of collagen I.

Inhibitory effect of Erigeron breviscapus extract and its flavonoid components on GABA shunt enzymes

Gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter, is metabolized by the successive action of GABA transaminase (GABA-T) and succinic semialdehyde dehydrogenase (SSADH). Inhibition of both enzymes in brain tissues increases the GABA level and may have therapeutic applications in neurological diseases. Erigeron breviscapus ethanol extract was evaluated for their effect on both enzymes. This extract, its ethyl acetate fraction and aqueous fraction, significantly inhibited them at >100 microg/ml. Flavonoid components of E. breviscapus potently and noncompetitively inhibited both enzymes, and the different structure-activity relations were observed with respect to inhibition of both enzymes. Baicalein was the most potent inhibitor for GABA-T with an IC50 value of 12.8+/-1.2 microM, and scutellarein exhibited the best inhibitory effect on SSADH with an IC50 value of 7.20+/-0.9 microM. The present results may imply new pharmacological actions of E. breviscapus and contribute partially to the beneficial effect of the herb and flavonoids on the central nervous system.

Effects of scutellarin on PKCgamma in PC12 cell injury induced by oxygen and glucose deprivation

AIM

To evaluate the neuroprotective effect and mechanisms of scutellarin (Scu) against PC12 cell injury after oxygen and glucose deprivation followed by reperfusion (OGD-Rep).

METHODS

Undifferentiated rat pheochromocytoma PC12 cells, exposed to oxygen and glucose deprivation followed by reperfusion (OGD-Rep), used as an in vitro model of ischemia/reperfusion. Cell survival was evaluated by diphenyltetrazolium bromide (MTT) assay and the amount of LDH release was determined using assay kits. [Ca2+](i) was monitored using a fluorescent Ca2+-sensitive dye Fura-2 acetoxymethyl ester. Cell apoptosis was detected by a DNA ladder and by flow cytometric detection. The expression of protein kinase C (PKC)gamma was determined using both RT-PCR and Western blotting. The translocation of PKCgamma was assayed by subcellular fractionation and Western blotting.

RESULTS

OGD-Rep injury significantly elevated the level of LDH release, [Ca2+](i), mRNA expression and the translocation of PKCgamma compared in the PC12 cells with those of the normal group. Scu (10-100 micromol/L) exerted a protective effect against OGD-Rep injury by reducing LDH release, [Ca2+](i), the percent of apoptosis, and the translocation of PKCgamma.

CONCLUSION

Scu inhibits the increase of [Ca2+](i) and the activation of PKCgamma, exerting protective effects against PC12 cell injury induced by OGD-Rep.

Separation of scutellarin from crude extracts of Erigeron breviscapus (vant.) Hand. Mazz. by macroporous resins

Scutellarin, a flavone glycoside, popularly used in the treatment of heart disease, has been efficiently separated using macroporous resins from crude extracts of Chinese medicinal plant Erigeron breviscapus (vant.) Hand. Mazz. HPD-800 resin offered the best adsorption and desorption capacity for scutellarin among the eight macroporous resins tested, and its adsorption data at 25 degrees C fit best to the Langmuir isotherm. The dynamic adsorption and desorption experiments have been carried out on a HPD-800 resin packed column to optimize the separation process of scutellarin from the crude extracts of E. breviscapus. After one run treatment with HPD-800 resin, the scutellarin content in the product was increased 15.69-fold from 2.61% to 40.96% with a recovery yield of 95.01%. The preparative separation process via adsorption-desorption method developed in this study provides a new approach for scale-up separation and purification of scutellarin for its wide pharmaceutical use.