Pro-angiogenic activity of notoginsenoside R1 in human umbilical vein endothelial cells in vitro and in a chemical-induced blood vessel loss model of zebrafish in vivo

OBJECTIVE

This study aimed at investigating whether notoginsenoside R1 (R1), a unique saponin found in Panax notoginseng could promote angiogenic activity on human umbilical vein endothelial cells (HUVECs) and elucidate their potential molecular mechanisms. In addition, vascular restorative activities of R1 was assessed in a chemically-induced blood vessel loss model in zebrafish.

METHODS

The in vitro angiogenic effect of R1 was compared with other previously reported angiogenic saponins Rg1 and Re. The HUVECs proliferation in the presence of R1 was determined by cell proliferation kit II (XTT) assay. R1, Rg1 and Re-induced HUVECs invasion across polycarbonate membrane was stained with Hoechst-33342 and quantified microscopically. Tube formation assay using matrigelcoated wells was performed to evaluate the pro-angiogenic actions of R1. In order to understand the mechanism underlying the pro-angiogenic effect, various pathway inhibitors such as SU5416, wortmannin (wort) or L-Nω-nitro- L-arginine methyl ester hydrochloride (L-NAME), SH-6 were used to probe the possible involvement of signaling pathway in the R1 mediated HUVECs proliferation. In in vivo assays, zebrafish embryos at 21 hpf were pre-treated with vascular endothelial growth factor (VEGF) receptor kinase inhibitor II (VRI) for 3 h only and subsequently post-treated with R1 for 48 h, respectively. The intersegmental vessels (ISVs) in zebrafish were assessed for the restorative effect of R1 on defective blood vessels.

RESULTS

R1 could stimulate the proliferation of HUVECs. In the chemoinvasion assay, R1 significantly increased the number of cross-membrane HUVECs. In addition, R1 markedly enhanced the tube formation ability of HUVECs. The proliferative effects of these saponins on HUVECs were effectively blocked by the addition of SU5416 (a VEGF-KDR/Flk-1 inhibitor). Similarly, pre-treatment with wort [a phosphatidylinositol 3-kinase (PI3K)-kinase inhibitor], L-NAME [an endothelial nitric oxide synthase (eNOS) inhibitor] or SH-6 (an Akt pathway inhibitor) significantly abrogated the R1 induced proliferation of HUVECs. In chemicallyinduced blood vessel loss model in zebrafish, R1 significantly rescue the damaged ISVs.

CONCLUSION

R1, similar to Rg1 and Re, had been showed pro-angiogenic action, possibly via the activation of the VEGF-KDR/Flk-1 and PI3K-Akt-eNOS signaling pathways. Our findings also shed light on intriguing pro-angiogenic effect of R1 under deficient angiogenesis condition in a pharmacologic-induced blood vessels loss model in zebrafish. The present study in vivo and in vitro provided scientific evidence to explain the ethnomedical use of Panax notoginseng in the treatment of cardiovascular diseases, traumatic injuries and wound healing.

Effectiveness assessment of soil conservation measures in reducing soil erosion in Baiquan County of Northeastern China by using (137)Cs techniques

Accelerated soil erosion is considered as a major land degradation process resulting in increased sediment production and sediment-associated nutrient inputs to the rivers. Over the last decade, several soil conservation programs for erosion control have been conducted throughout Northeastern China. Reliable information on soil erosion rates is an essential prerequisite to assess the effectiveness of soil conservation measures. A study was carried out in Baiquan County of Northeastern China to assess the effectiveness of soil conservation measures in reducing soil erosion using the (137)Cs tracer technique and related techniques. This study reports the use of (137)Cs measurements to quantify medium-term soil erosion rates in traditional slope farmland, contour cropping farmland and terrace farmland in the Dingjiagou catchment and the Xingsheng catchment of Baiquan County. The (137)Cs reference inventory of 2532 ± 670 Bq m(-2) was determined. Based on the principle of the (137)Cs tracer technique, soil erosion rates were estimated. The results showed that severe erosion on traditional slope farmland is the dominant soil erosion process in the area. The terrace measure reduced soil erosion rates by 16% for the entire slope. Typical net soil erosion rates are estimated to be 28.97 Mg per hectare per year for traditional slope farmland and 25.04 Mg per hectare per year for terrace farmland in the Dingjiagou catchment. In contrast to traditional slope farmland with a soil erosion rate of 34.65 Mg per hectare per year, contour cultivation reduced the soil erosion rate by 53% resulting in a soil erosion rate of 22.58 Mg per hectare per year in the Xingsheng catchment. These results indicated that soil losses can be controlled by changing tillage practices from the traditional slope farmland cultivation to the terrace or contour cultivation.

Record-high and robust 17.125 Gb/s gross-rate over 25 km SSMF transmissions of real-time dual-band optical OFDM signals directly modulated by 1 GHz RSOAs

Aggregated 17.125 Gb/s real-time end-to-end dual-band optical OFDM (OOFDM) transmissions over 25 km SSMF IMDD systems with 7 dB receiver sensitivity improvements are experimentally demonstrated, for the first time, by utilizing low-cost transceiver components such as directly modulated 1GHz RSOAs and DACs/ADCs operating at sampling speeds as low as 4GS/s. The demonstrated OOFDM transceivers have both strong adaptability and sufficiently large passband carrier frequency tunability, which enable full use of highly dynamic spectral characteristics of the transmission systems. This results in the achievements of not only excellent performance robustness to variations in system operating conditions but also significantly relaxed requirements on RSOA small-signal modulation bandwidth. It is shown that the aforementioned transmission capacity only varies by <23% over a RSOA-injected optical power variation range as large as 20dB, and that the 1 GHz RSOAs can support successful transmissions of adaptively modulated OOFDM signals having bandwidths of 8.5 GHz. By taking into account the adopted 25% cyclic prefix and a typical 7.3% FEC overhead, the demonstrated real-time OOFDM transmission systems are capable of conveying 11.6 Gb/s user data.

Robust real-time 15.125 Gb/s adaptive optical OFDM transmissions over 100 m OM2 MMFs utilizing directly modulated VCSELs subject to optical injection locking

Optical injection locking (OIL) is an effective approach for significantly enhancing the modulation bandwidths of VCSELs. The frequency responses of OIL-VCSELs are, however, very sensitive to the applied OIL conditions. This brings about strong difficulties in practically utilizing the OIL-enhanced modulation bandwidths to achieve highly robust transmission performances of directly modulated OIL-VCSEL-based multi-mode fibre (MMF) links for cost-sensitive application scenarios such as data-centers. In this paper, directly modulated OIL-VCSEL-based real-time dual-band optical OFDM (OOFDM) transceivers with tunability in both the electrical and optical domains are experimentally demonstrated, for the first time, utilizing DACs/ADCs at sampling speeds as low as 4GS/s. The transceivers can support 15.125 Gb/s adaptive OOFDM transmissions over 100 m OM2 MMF links based on intensity modulation and direct detection. More importantly, the adaptability and tunability of the demonstrated transceivers enable the achievement of excellent robustness of the aggregated OOFDM transmission capacity to OIL condition variations. It is shown that, over a large diversity of OIL conditions that give rise to significantly different system frequency responses, the aggregated OOFDM transmission capacity only vary by <11% in the aforementioned transmission link.

[Chemical studies on roots of Ficus hirta]

Seventeen compounds were isolated from the 95% ethanolic extract of the root of Ficus hirta. Their structures were identified on the basis of physicochemical properties and spectral data analysis. The structures were elucidated as cyclomorusin (1), 3-O-[(6-O-E-sinapoyl)-beta-D-glucopyranosyl]-(1 --> 2)-beta-D-glucopyranoside (2), 3,5,4'-trihydroxy-6,7,3'-trimethoxyflavone (3), quercetin (4), tricin (5), acacetin (6), luteolin (7), apigenin (8), (E) -suberenol (9), meranzin hydrate (10), methyl eugenol (11), 3-methoxy-4-hydroxybenzoic acid (12), p-hydroxybenzoic acid (13), methyl chlorogenate (14), emodin (15), alpha-amyrin acetate (16), and beta-sitosterol emodin (17), respectively. Compounds 1-6, 9-15 were isolated from this plant for the first time.

Ganoderiol A-enriched extract suppresses migration and adhesion of MDA-MB-231 cells by inhibiting FAK-SRC-paxillin cascade pathway

Cell adhesion, migration and invasion are critical steps for carcinogenesis and cancer metastasis. Ganoderma lucidum, also called Lingzhi in China, is a traditional Chinese medicine, which exhibits anti-proliferation, anti-inflammation and anti-metastasis properties. Herein, GAEE, G. lucidum extract mainly contains ganoderiol A (GA), dihydrogenated GA and GA isomer, was shown to inhibit the abilities of adhesion and migration, while have a slight influence on that of invasion in highly metastatic breast cancer MDA-MB-231 cells at non-toxic doses. Further investigation revealed that GAEE decreased the active forms of focal adhesion kinase (FAK) and disrupted the interaction between FAK and SRC, which lead to deactivating of paxillin. Moreover, GAEE treatment downregulated the expressions of RhoA, Rac1, and Cdc42, and decreased the interaction between neural Wiskott-Aldrich Syndrome protein (N-WASP) and Cdc42, which impair cell migration and actin assembly. To our knowledge, this is the first report to show that G.lucidum triterpenoids could suppress cell migration and adhesion through FAK-SRC-paxillin signaling pathway. Our study also suggests that GAEE may be a potential agent for treatment of breast cancer.

Flavonoids with α-glucosidase inhibitory activities and their contents in the leaves of Morus atropurpurea

Background

This study aims to isolate the α-glucosidase inhibitory compounds from mulberry leaves (Morus atropurpurea Roxb., Moraceae) and to develop an analytical method for quantification of the compounds.

Methods

Four flavonoids, rutin (1), isoquercetin (2), kaempferol-3-O-rutinoside (3) and astragalin (4), were isolated by column chromatography from mulberry leaf water extracts (MWE). The α-glucosidase inhibitory activities of MWE and the four isolated compounds were evaluated by a microplate-based in vitro assay. The content of the isolated flavonoids in M. atropurpurea leaves purchased from different local herbal stores or collected in different locations was determined by high performance liquid chromatography.

Results

The four flavonoids (1–4) showed α-glucosidase inhibitory activities, with rutin (1) and astragalin (4) showing high α-glucosidase inhibitory activities (IC₅₀ values of 13.19 ± 1.10 and 15.82 ± 1.11 μM, respectively). The total contents of the four flavonoids were different among eight samples examined, ranging from 4.34 mg/g to 0.53 mg/g.

Conclusions

The four flavonoids in M. atropurpurea leaves could inhibit α-glucosidase activity.

α-Glucosidase inhibitory effect and simultaneous quantification of three major flavonoid glycosides in Microctis folium

Microctis Folium, the leaves of Microcos paniculata L., is a commonly used herbal tea material. The methanol extract of Microctis Folium and its principle compounds vitexin (1), isovitexin (2) and isorhamnetin 3-O-β-d-rutinoside (3) were investigated for their α-glucosidase inhibitory effects. The extract showed strong α-glucosidase inhibitory effect (IC₅₀ = 61.30 μg/mL) and the three flavonoid glycosides 1–3 exerted satisfactory α-glucosidase inhibitory effects, with IC₅₀ values of 244.0 μM, 266.2 μM and 275.4 μM, respectively. A simple and reliable HPLC-DAD method was developed for the quantification of the three flavonoid glycosides in Microctis Folium and applied successfully to determine contents of these components in samples collected from different locations. This study suggested that Microctis Folium may be a promising candidate for development of herbal antidiabetes drugs, and vitexin, isovitexin and isorhamnetin 3-O-β-d-rutinoside can be the biomarkers and chemical markers for this plant substance.

Experimental demonstrations of record high REAM intensity modulator-enabled 19.25Gb/s real-time end-to-end dual-band optical OFDM colorless transmissions over 25km SSMF IMDD systems

Record-high 19.25Gb/s real-time end-to-end dual-band optical OFDM (OOFDM) colorless transmissions across the entire C-band are experimentally demonstrated, for the first time, in reflective electro-absorption modulator (REAM)-based 25km standard SMF systems using intensity modulation and direct detection. Adaptively modulated baseband (0-2GHz) and passband (6.125 ± 2GHz) OFDM RF sub-bands, supporting signal line rates of 9.75Gb/s and 9.5Gb/s respectively, are independently generated and detected with FPGA-based DSP clocked at only 100MHz as well as DACs/ADCs operating at sampling speeds as low as 4GS/s. The two OFDM sub-bands are electrically multiplexed for intensity modulation of a single optical carrier by an 8GHz REAM. The REAM colorlessness is experimentally characterized, based on which optimum REAM operating conditions are identified. To maximize and balance the signal transmission performance of each sub-band, on-line adaptive transceiver optimization functions and live performance monitoring are fully exploited to optimize key OOFDM transceiver and system parameters. For different wavelengths within the C-band, corresponding minimum received optical powers at the FEC limit vary in a range of <0.5dB and bit error rate performances for both baseband and passband signals are almost identical. Furthermore, detailed investigations are also undertaken of the maximum aggregated signal line rate sensitivity to electrical sub-band power variation. It is shown that the aforementioned system has approximately 3dB tolerance to RF sub-band power variation.

Retrieving quasi-phase-matching structure with discrete layer-peeling method

An approach to reconstruct a quasi-phase-matching grating by using a discrete layer-peeling algorithm is presented. Experimentally measured output spectra of Šolc-type filters, based on uniform and chirped QPM structures, are used in the discrete layer-peeling algorithm. The reconstructed QPM structures are in agreement with the exact structures used in the experiment and the method is verified to be accurate and efficient in quality inspection on quasi-phase-matching grating.

[Chemical constituents from the aerial roots of Ficus microcarpa]

OBJECTIVE

To study the chemical constituents of the aerial roots of Ficus microcarpa.

METHODS

The compounds were isolated and purified by column chromatographic methods on silica gel and Sephadex LH-20. Their structures were elucidated by physicochemical properties and spectral data.

RESULTS

12 compounds were isolated from the 95% ethanol extract. Their structures were idenified as 3beta-hydroxy-11-oxours-12-ene (1), 3beta-acetoxy-11-oxours-12-ene (2), oleanic acid (3), 3beta-hydroxy-oleana-11,13 (18)-dien-28-oic acid (4), betulinic acid (5), pyracrenic acid (6), platanic acid (7), isowigtheone (8), myrsininone A (9), derrone (10), alpinumisoflavone (11) and caffeic acid methyl ester (12), respectively.

CONCLUSION

Compounds 4, 6, 12 are obtained from this genus for the first time, compounds 1, 7 - 11 are isolated from this plant for the first time.

Simultaneous quantification of major flavonoids in "Bawanghua", the edible flower of Hylocereus undatus using pressurised liquid extraction and high performance liquid chromatography

A pressurised liquid extraction (PLE) and high performance liquid chromatography (HPLC) method was developed for simultaneous quantification of six major flavonoids in edible flower of Hylocereus undatus. In order to achieve the baseline separation of two pairs of isomers, the HPLC conditions were optimised with different kind of reversed phase columns and mobile phase gradient programs. In addition, the solvent concentration, extraction temperature, extraction time and flush cycle for PLE were also optimised. Zorbax SB-C8 (100×2.1 mm, 1.8 μm) column was chosen with acetonitrile and water containing 0.1% trifluoroacetic acid as mobile phase, the six analytes were eluted with baseline separation. The calibration curves showed good linearity (r(2)>0.9994) with LODs and LOQs less than 0.90 and 3.60 ng respectively. The RSDs for intra- and inter-day repeatability was not more than 1.09% and 1.79% respectively. The overall recovery of the assay was 96.9-105.2%. The sample was stable for at least 12 h. The newly established method was successfully applied to quantify six flavonoids in different parts of "Bawanghua", and the commercial samples from different locations.

Enantioseparation and absolute configuration determination of angular-type pyranocoumarins from peucedani radix using enzymatic hydrolysis and chiral HPLC-MS/MS analysis

Angular-type pyranocoumarins from Peucedani Radix (Chinese name: Qian-hu) have exhibited potential for use on treatment of cancer and pulmonary hypertension. Due to the existence of C-3' and C-4' chiral centers, compounds belonging to this chemical type commonly exist in enantiomers and/or diastereoisomers, which may elicit distinct activities during their interactions with the human body. In the present study, a new method, which combines enzymatic hydrolysis with chiral LC-MS/MS analysis, has been developed to determine the absolute configurations of these angular-type pyranocoumarins. Pyranocoumarins isolated from Qian-hu, their enantiomers, or metabolites were individually incubated with rat liver microsomes. As the common end product from enzymatic hydrolysis of all tested pyranocoumarins, cis-khellactone was collected and its absolute configuration was determined by comparison with (+)-cis-khellactone and (-)-cis-khellactone using chiral LC-MS/MS. The absolute configurations of all tested parent pyranocoumarins were determined by combination of LC-MS/MS, NMR and polarimetric analysis. The results revealed that the metabolite cis-khellactone retained the same absolute configurations of the stereogenic carbons as the respective parent compound. This method was proven to be rapid and sensitive and also has advantages in discriminating single enantiomers and mixtures of optical isomers with different ratios.

Four new triterpenoids from the leaves of Psidium guajava

Four new triterpenoids, psiguanins A-D (1-4), along with 13 known ones (5-17), were isolated from the leaves of Psidium guajava. The structures of new compounds were determined as 2α,3β-dihydroxy-taraxer-20-en-28-oic acid (1), 2α,3β,12α,13β-tetrahydroxy-urs-28-oic acid (2), 2α,3β,12β,13β-tetrahydroxy-urs-28-oic acid (3), and 2α,3β,12β,13α-tetrahydroxy-urs-28-oic acid (4), respectively, on the basis of comprehensive spectroscopic methods and molecular modeling calculation. Among them, compound 4 was characterized as an unusual ursane-type triterpenoid with cis-fused C/D ring system.

Two new saponins from Thalictrum fortunei

Two new cycloartane glycosides were isolated from the aerial parts of Thalictrum fortunei (Ranunculaceae). The chemical structures of these compounds were elucidated as 3-O-β-D-glucopyranosyl (1 → 4)-β-d-fucopyranosyl-(22S,24Z)-cycloart-24-en-3β,22,26,30-tetraol 26-O-β-D-glucopyranoside and 3-O-β-D-glucopyranosyl (1 → 4)-β-D-fucopyranosyl-(22S,24Z)-cycloart-24-en-3β,22,26,29-tetraol 26-O-β-D-glucopyranoside by extensive 1D and 2D NMR methods, HR-ESI-MS, and hydrolysis. Their cytotoxic activities toward human hepatoma Bel-7402 cells, human colon carcinoma LoVo cells, and human non-small-cell lung cancer NCIH-460 cells were evaluated by MTT assay, respectively.