Application of UPLC-Triple TOF-MS/MS metabolomics strategy to reveal the dynamic changes of triterpenoid saponins during the decocting process of Asian ginseng and American ginseng.

Triterpenoid saponins are the main bioactive components contributed to the nutritional value of ginseng, and different process conditions will affect their content and quality. To study the holistic characterization and dynamic changes of triterpenoid saponins in Asian ginseng (ASG) and American ginseng (AMG) during soaking and decoction, a UPLC-Triple TOF-MS/MS-based metabolomics strategy was used to characterize and discover differential saponin markers. In total, 739 triterpenoid saponins (including 225 potential new saponins) were identified from ASG and AMG in untargeted metabolomics. Based on PCA and OPLS-DA, 51 and 48 saponin markers were screened from soaked and decocted ASG and AMG, respectively. Additionally, targeted metabolomics analysis and HCA of 22 ginsenoside markers suggested that decoction of ASG and AMG for 2 h to 4 h could significantly increase the contents of rare ginsenosides (G), such as G-Rg3, G-Rg5, G-F4. This study provides a scientific insight that high boiling combined with simmering enriches ASG and AMG extracts with rich rare ginsenosides that are more beneficial to human health.

Extraction optimization, structure features, and bioactivities of two polysaccharides from Corydalis decumbens.

Two polysaccharides (CPS1 and CPW2) from Corydalis decumbens were obtained to develop insights into natural medical resources. Optimal extraction conditions of total sugars were researched using the method of response surface methodology, polysaccharides were purified using a combination of ethanol precipitation and anion-exchange chromatography, and structure features were analyzed by scanning electron microscopy, transmission electron microscopy, and Congo-red assay. The bioactivities were estimated in terms of antioxidant and anti-inflammatory effects. Total sugars were extracted with an experimental yield of 32.74% under optimum conditions. CPS1 and CPW2 were purified with yields of 12.01% and 8.23%, respectively. CPS1 was a unique polysaccharide with a molecular weight (Mw) of 360 kDa and consisted of glucose, galactose, mannose, and arabinose in a ratio of 4.9:2.0:1:1.9, and CPW2 was composed of glucose with the Mw of 550 kDa. CPS1 possessed a four-helix conformation, and CPW2 was identified as a linear molecule without branched and entangled chains. The mRNA expressions of TNF-α (71.80%), IL-1ß (56.55%), IL-6 (43.98%), and COX-2 (91.88%) in LPS-stimulated RAW 264.7 cells were significantly inhibited by 75 µg/mL CPS1 (P < 0.0001), while CPW2 showed lower inhibitory effects than CPS1. Compared with CPW2, CPS1 showed stronger scavenging abilities for hydroxyl (EC50 = 520.46 µg/mL), ABTS (EC50 = 533.99 µg/mL), and superoxide (EC50 = 1512.06 µg/mL) radicals. CPS1 with four-helix conformation exhibited more outstanding bioactivities than CPW2 without entangled chains.

Electric dipole modulation for boosting carrier recombination in green InP QLEDs under strong electron injection.

Enhanced and balanced carrier injection is essential to achieve highly efficient green indium phosphide (InP) quantum dot light-emitting diodes (QLEDs). However, due to the poor injection of holes in green InP QLEDs, the carrier injection is usually balanced by suppressing the strong electron injection, which decreases the radiation recombination rate dramatically. Here, an electric dipole layer is introduced to enhance the hole injection in the green InP QLED with a high mobility electron transport layer (ETL). The ultra-thin MoO3 electric dipole layer is demonstrated to form a positive built-in electric field at the interface of the hole injection layer (HIL) and hole transport layer (HTL) due to its deep conduction band level. Simulation and experimental results support that strong electric fields are produced for efficient hole hopping, and the carrier recombination rate is substantially increased. Consequently, the green InP QLEDs based on enhanced electron and hole injection have achieved a high luminance of 52 730 cd m-2 and 1.7 times external quantum efficiency (EQE) enhancement from 4.25% to 7.39%. This work has provided an effective approach to enhance carrier injection in green InP QLEDs and indicates the feasibility to realize highly efficient green InP QLEDs.

Corylin ameliorates chronic ulcerative colitis via regulating the gut-brain axis and promoting 5-hydroxytryptophan production in the colon.

BACKGROUND: Chronic ulcerative colitis (UC) is a lifelong disease, patients with chronic UC have a high prevalence of common mental disorders. The increasing interest in the role of gut-brain axis is seen in inflammatory bowel diseases. PURPOSE: Corylin is a representative flavonoid compound isolated from the Psoraleae Fructus. This study aimed to identify the effects and mechanism of corylin on the inflammation interactions and 5-HT synthesis between the gut and brain in chronic UC. METHODS: Dextran sulfate sodium (DSS) induced chronic UC mouse model was established to assess the therapeutic effect of corylin on chronic UC symptoms. The expression of inflammatory cytokines was detected in the colon and brain. The expression of tight junction (TJ) proteins of intestinal mucosal barrier and blood-brain barrier (BBB) and the ionized calcium-binding adaptor molecule 1 (Iba1) in the hippocampus were determined by western blotting and immunofluorescence staining. In addition, several tryptophan (Trp) metabolites and related neurotransmitters in faeces, colon, serum, and brain were detected by UPLC-MS/MS. The interaction between corylin and 5-hydroxytryptophan decarboxylase (5-HTPDC) was performed by molecular docking and surface plasmon resonance (SPR). Finally, the changes of gut microbiota composition were analyzed by 16S rRNA sequencing. RESULTS: Corylin significantly alleviated colitis symptoms and inhibited inflammatory response in the colon and brain of DSS-induced chronic UC mice. The TJ proteins of intestinal mucosal barrier and BBB were improved and the expression of Iba1 in the hippocampus was normalized after corylin treatment. In addition, corylin treatment increased the expression of neurotransmitters in the brain, especially 5-hydroxytryptamine (5-HT) and 5-hydroxytryptophan (5-HTP), but the expression of 5-HT in the colon was inhibited. Further study firstly proved that corylin could bind to the 5-HTDPC, and then inhibit the expression of 5-HTDPC and VB6, resulting in the 5-HT reduction and 5-HTP accumulation in the colon. Moreover, the intake of corylin transformed the diversity and composition of intestinal microbiota, Bacteroides, Escherichia-Shigella, and Turicibacter were decreased but Dubosiella, Enterorhabdus, and Candidatus_Stoquefichus were increased. CONCLUSION: Corylin administration ameliorated DSS-induced colitis and inhibited intestinal inflammation and neuroinflammation via regulating the inflammation interactions across gut-brain axis and increasing 5-HTP generation in the colon.

Flavonoids dimers from the fruits of Psoralea corylifolia and their cytotoxicity against MCF-7 cells.

Nine new flavonoids dimers, psocorylins R-Z (1-9), were isolated from the fruits of Psoralea corylifolia L. (Psoraleae Fructus), a traditional Chinese medicine. The structures of these compounds were elucidated via multiple spectroscopic techniques and X-ray diffraction. Psocorylins R (1) and S (2) were rare cyclobutane-containing chalcone dimers, and psocorylins T-Z (3-9) were established by CC or COC bond of two flavonoid monomers. The structural-types, flavonoids dimers, were isolated from the plant for the first time, enriching the chemical diversity. The cytotoxicity assay suggested that compounds 1, 2, 4, 5, 6 and 8 exhibited cytotoxic activities against MCF-7 cells. Furthermore, compounds 1 and 8 significantly increased intracellular ROS levels, decreased MMP and induced apoptosis of MCF-7 cells. They markedly upregulated the expression of Bax and cleaved caspase-3, and suppressed Bcl-2 and caspase-3 levels, indicating their mechanism of Bcl-2/Bax/Cleaved caspase-3 pathway. Hence, our findings not only promoted the chemical investigation of Psoraleae Fructus, but also provided potential bioactive natural products for anti-cancer.

The benzofuran glycosides from the fruits of Psoralea corylifolia L.

Six new glucosides of benzofuran (1-6), together with three known glucosides of benzofuran (8, 9, 14), nine flavonoids (12, 13, 15, 18, 19, 20, 21, 22 and 24), three coumarins (16, 17, 23) and four other-typic compounds (7, 10, 11 and 25) were isolated from the fruits of Psoralia corylifolia L. Their structures were elucidated by extensive spectroscopic methods. The biosynthesis pathway of benzofuran system was discussed. Besides, all isolated compounds and additional ring-opening derivatives of psoralen/isopsoralen (P-1, P-2, IP-1 and IP-2) were assayed for inhibition of nitric oxide (NO) production on lipopolysaccharides-induced RAW 264.7 macrophage cells. The results of the assay showed that the glycosides showed weaker or no effects, while most isolated non-glycoside compounds showed moderate or high activities. And the structure-activity relationships of non-glycoside compounds were discussed.

circHIPK3 Promotes Cell Proliferation and Migration of Gastric Cancer by Sponging miR-107 and Regulating BDNF Expression.

BACKGROUND: Circular RNAs (circRNAs) play important regulatory roles in cancer development. However, the mechanisms by which circRNAs regulate gene expression in gastric cancer (GC) remain unclear. METHODS: Human GC samples and their matched normal adjacent tissues were obtained from 30 patients to assess the expression of circHIPK3 and its relationship with GC proliferation and migration. A series of in vitro and in vivo functional experiments were carried out to elucidate the role of circHIPK3 in GC proliferation and migration, and its underlying molecular mechanisms. RESULTS: Using a circRNA microarray we found a circRNA termed circHIPK3 that performed a significant regulatory role in GC. circHIPK3 was further confirmed to be upregulated in all GC tissues and cells tested. Furthermore, circHIPK3 levels were associated with Tumor & Lymph Node & Metastasis(TNM) stage (P = 0.032). The area under the receiver operating characteristic curve (ROC) was 0.743 (95% confidence interval 0.615-0.872; P = 0.001). CCK-8, colony formation, Transwell and EdU assays were performed to evaluate the effects of circHIPK3 on cell proliferation and migration in GC. Moreover, circHIPK3 was identified as a sponge of miR-107, and as such it regulated brain-derived neurotrophic factor (BDNF), which plays a pivotal role in the development of GC. CONCLUSION: circHIPK3 represents a novel potential biomarker and therapeutic target of GC.

A polysaccharide from Umbilicaria yunnana: Structural characterization and anti-inflammation effects.

A polysaccharide JUYP was isolated and purified from Umbilicaria yunnana. The detailed structure of JUYP was studied using gas chromatography (GC), Fourier transform infrared spectroscopy (FTIR), methylation-GC-MS, nuclear magnetic resonance (NMR) and transmission electron microscopy (TEM). A homogeneous polysaccharide JUYP was obtained with the yield of 21.2% and average molecular weight (Mw) of 577 kDa. Monosaccharide composition analysis indicated that JUYP was composed of glucose, galactose and mannose with a molar ratio of 2.3:1:0.7. Structural analyses demonstrated that the dominate components in JUYP were 6-ß-D-Glcp, and other sugar residues included 2,4-ß-D-Manp and T-ß-D-Galf. TEM images further revealed JUYP was a linear branched molecule with entangled chains. Based on the anti-inflammatory assays, 1 µg/mL of JUYP exhibited good inhibitory effects on TNF-α, IL-6, IL-1ß and COX-2 mRNA expressions in LPS-stimulated RAW 264.7 cells, while the inhibitory effects (87.8% for mRNA, 55.89% for protein) of JUYP on IL-1ß expressions were more significant than that of dexamethasone (DXMS, 61.6% for mRNA, 35.15% for protein) (p<0.01).

Circular RNA hsa_circRNA_102958 may serve as a diagnostic marker for gastric cancer.

BACKGROUND: Circular RNAs (circRNA) play key regulatory roles in cancer progression. Human circRNA microarray was performed to screen for abnormally expressed circRNA in gastric cancer tissues. In this study, we found circRNA102958 was up-regulated in gastric cancer tissues and cell lines. METHODS: The hsa_circRNA_102958 levels were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in gastric tissue and cell. Then, the association between the expression level of hsa_circRNA_102958 and the clinicopathological features of patients with gastric cancer was further analyzed. Finally, a network of hsa_circRNA_102958-miRNA-mRNA interactions was predicated. RESULTS: In this study, we analyzed 30 patients and found that hsa_circRNA_102958 was significantly overexpressed in gastric cancer tissues compared with paired adjacent normal tissues. Clinicopathological features showed that hsa_circRNA_102958 level in GC tissues was positively associated with TNM stage (p= 0.032). The area under the ROC curve was 0.74. Finally, a total of 5 miRNAs were predicted to have an interaction with hsa_circRNA_102958. CONCLUSIONS: hsa_circRNA_102958 may be a potential novel and stable biomarker for the diagnosis of gastric carcinoma.

Structural characterization of a novel polysaccharide from Sargassum thunbergii and its antioxidant and anti-inflammation effects.

A novel polysaccharide STSP-I was isolated and purified from Sargassum thunbergii. Its structure and bioactivity were studied using gas chromatography (GC), fourier transform infrared spectroscopy (FTIR), periodate oxidation-smith degradation, partial acid hydrolysis, methylation-GC-MS, nuclear magnetic resonance (NMR), transmission electron microscopy (TEM), radicals scavenging assays and anti-inflammatory assays. STSP-I was consisted of fucose and galactose with a molar ratio of 1.2:1, and its mass was 373 kDa. The main structural components of STSP-I were →4)-α-D-Galp-(1→ and →3)-ß-L-Fucp-(1→, STSP-I was a non-branched polysaccharide, and TEM further revealed the existence of entangled chains and linear forms. Compared with Vitamin C (Vc), STSP-I showed a higher scavenging effect of superoxide radical (EC50 = 0.22 mg/mL) and an equivalent scavenging effect of hydroxyl radical (EC50 = 0.88 mg/mL). STSP-I also exhibited good inhibitory effects of TNF-α, IL-6 and COX-2 mRNA expressions in LPS-stimulated RAW 264.7 mouse macrophage cells, and the inhibitory effects were more than 91% at the concentrations of 75 and 150 µg/ml. The results indicate that the polysaccharide STSP-I from S. thunbergii with the linear structure may serve as potential antioxidant and anti-inflammatory agents.

Clinicopathological and prognostic significance of CDH1 hypermethylation in hepatocellular carcinoma: a meta-analysis.

BACKGROUND: The patients with hepatocellular carcinoma (HCC) have poor prognosis due to being diagnosed at late stage or recurrence following surgery. It's critical to identify effective biomarkers that can improve overall diagnosis and treatment of HCC. METHODS: We performed a meta-analysis of all relative studies reporting the clinicopathological significance of CDH1 hypermethylation in HCC by using Review Manager 5.2. A comprehensive literature search was performed in EMBASE, PubMed, Web of Science and Google Scholar databases. Kaplan Meier Plotter online database was used for the determination of correlation between CDH1 mRNA expression and overall survival in patients with HCC. Odds Ratios (OR) with 95% corresponding confidence intervals (CIs) were calculated. A total of 12 relevant studies were included in the meta-analysis with 981 patients. RESULTS: The positive rate of CDH1 hypermethylation was significantly higher in HCC than in normal liver tissue; and the pooled OR was 4.34 with 95% CI 2.50-7.56, P<0.00001. CDH1 promoter in HCC was more frequently hypermethylated compared to the group of chronic liver disease (CLD); OR was 4.83 with 95% CI 2.67-8.72, P<0.00001. However, the rate of CDH1 promoter hypermethylation was not correlated with different grades as well as stages. High CDH1 mRNA expression was significantly correlated to better overall survival in all 231 HCC patients compared to 133 HCC patients with low level CDH1 mRNA expression; HR was 0.6 with 95% CI 0.42-0.85, P=0.0034. CONCLUSION: In summary, CDH1 promoter hypermethylation is a risk factor and promising biomarker for HCC carcinogenesis and diagnosis, as well as a predictor of poor prognosis.

Economic evaluation of cervical cancer screening strategies in urban China.

OBJECTIVE: This study evaluated the feasibility of different cervical cancer screening strategies in urban China. METHODS: A Markov model was constructed to simulate a hypothetical cohort of 100,000 females aged 30-59 years in a 20-year period. Screening strategies included liquid-based cytology (LBC) every three years, human papillomavirus (HPV) DNA testing every three and five years, respectively, and a combination of HPV DNA testing and LBC (HPV+LBC) every three and five years, respectively. Model outcomes included cumulative incidence over 20 years, cumulative risk of cervical cancer, costs, life year saved (LYS), quality-adjusted life years (QALYs) and benefits. The cost-effectiveness ratios (CERs), incremental cost-effectiveness ratios (ICERs), cost-utility ratios (CURs), and benefit-cost ratios (BCRs) were used as outcomes in the health economic evaluation analysis. Univariate sensitivity analyses were performed to examine the stability of the results. RESULTS: The cumulative incidence of the five screening strategies ranged from 833.02 to 1,158.07 cases per 100,000 females. HPV DNA testing was most effective in reducing the cumulative risk of cervical cancer, saving life years and QALYs and gaining benefits. The CERs of HPV DNA testing every three and five years, and LBC every three years were considered to be very cost-effective if they were below China's GDP per capita. The CERs of HPV+LBC were considered to be cost-effective if they were below three times GDP per capita. The incremental cost-effectiveness analysis showed that HPV DNA testing every three and five years, LBC every three years and HPV+LBC every five years were dominant strategies. CONCLUSIONS: The findings of this study indicated that HPV DNA testing every five years or LBC every three years should be recommended in urban China.

Structure of an entangled heteropolysaccharide from Pholidota chinensis Lindl and its antioxidant and anti-cancer properties.

A major polysaccharide PCP-I was isolated and purified from Pholidota chinensis Lindl. The physicochemical and structural properties of PCP-I were studied using high-performance size-exclusion chromatography (HPSEC), gas chromatography (GC), Fourier transform infrared spectroscopy (FTIR), periodate oxidation-smith degradation, methylation-GC-MS analysis, nuclear magnetic resonance (NMR) spectroscopy and transmission electron microscopy (TEM) analysis. PCP-I was homogeneous with molecular weight (Mw) of 249kDa and composed of xylose and fucose at a molar ratio of 2.45:1. The repeating structural units of PCP-I were →3)-α-D-Xylp-(1→ and →4)-α-L-Fucp-(1→, the terminal fractions were T-D-GalAp, and TEM further revealed that PCP-I was the entangled microstructure which was composed of four non-branched single chains. Compared with Vitamin C (Vc) and 5 fluorine urine (5-Fu), PCP-I showed scavenging effects of superoxide (EC50=1.09mg/mL) and hydroxyl (EC50=0.11mg/mL) radicals equivalent to Vc, and PCP-I (IC50=69.54µg/mL) also exhibited good anti-proliferation capability for human colon cancer cell line caco-2.

Stabilization of Notch1 by the Hsp90 Chaperone Is Crucial for T-Cell Leukemogenesis.

Purpose: Notch1 deregulation is assuming a focal role in T-cell acute lymphoblastic leukemia (T-ALL). Despite tremendous advances in our understanding of Notch1 transcriptional programs, the mechanisms by which Notch1 stability and turnover are regulated remain obscure. The goal of the current study is to identify intracellular Notch1 (ICN1, the activated form of Notch1) binding partner(s) regulating its stability and activity. Experimental Design: We employed immunoaffinity purification to identify ICN1-associating partner(s) and used coimmunoprecipitation to verify the endogenous protein interaction. Pharmacologic or short hairpin RNA-mediated inhibition was applied in loss-of-function assays to assess the role of tentative binding partner(s) in modulating ICN1 protein stability as well as affecting T-ALL cell expansion in vitro and in vivo Mechanistic analysis involved protein degradation and polyubiquitination assays. Results: We identify the Hsp90 chaperone as a direct ICN1-binding partner essential for its stabilization and transcriptional activity. T-ALL cells exhibit constitutive endogenous ICN1-Hsp90 interaction and Hsp90 depletion markedly decreases ICN1 levels. The Hsp90-associated E3 ubiquitin ligase Stub1 mediates the ensuring proteasome-dependent ICN1 degradation. Administration of 17-AAG or PU-H71, two distinct Hsp90 inhibitors, depletes ICN1, inhibits T-ALL cell proliferation, and triggers dramatic apoptotic cell death. Systemic treatment with PU-H71 reduces ICN1 expression and profoundly inhibits murine T-ALL allografts as well as human T-ALL xenografts. Conclusions: Our findings demonstrate Hsp90 blockade leads to ICN1 destabilization, providing an alternative strategy to antagonize oncogenic Notch1 signaling with Hsp90-selective inhibitors. Clin Cancer Res; 23(14); 3834-46. ©2017 AACR.

Quantitative Structure Activity Relationship Models for the Antioxidant Activity of Polysaccharides.

In this study, quantitative structure activity relationship (QSAR) models for the antioxidant activity of polysaccharides were developed with 50% effective concentration (EC50) as the dependent variable. To establish optimum QSAR models, multiple linear regressions (MLR), support vector machines (SVM) and artificial neural networks (ANN) were used, and 11 molecular descriptors were selected. The optimum QSAR model for predicting EC50 of DPPH-scavenging activity consisted of four major descriptors. MLR model gave EC50 = 0.033Ara-0.041GalA-0.03GlcA-0.025PC+0.484, and MLR fitted the training set with R = 0.807. ANN model gave the improvement of training set (R = 0.96, RMSE = 0.018) and test set (R = 0.933, RMSE = 0.055) which indicated that it was more accurately than SVM and MLR models for predicting the DPPH-scavenging activity of polysaccharides. 67 compounds were used for predicting EC50 of the hydroxyl radicals scavenging activity of polysaccharides. MLR model gave EC50 = 0.12PC+0.083Fuc+0.013Rha-0.02UA+0.372. A comparison of results from models indicated that ANN model (R = 0.944, RMSE = 0.119) was also the best one for predicting the hydroxyl radicals scavenging activity of polysaccharides. MLR and ANN models showed that Ara and GalA appeared critical in determining EC50 of DPPH-scavenging activity, and Fuc, Rha, uronic acid and protein content had a great effect on the hydroxyl radicals scavenging activity of polysaccharides. The antioxidant activity of polysaccharide usually was high in MW range of 4000-100000, and the antioxidant activity could be affected simultaneously by other polysaccharide properties, such as uronic acid and Ara.

Structure elucidation of a non-branched and entangled heteropolysaccharide from Tremella sanguinea Peng and its antioxidant activity.

A crude polysaccharide was extracted from the edible fungi Tremella sanguinea Peng, and a polysaccharide TSP-II (31.56%) was separated and purified from the crude polysaccharide. TSP-II was a homogeneous polysaccharide by the high-performance size-exclusion chromatography (HPSEC), had a molecular weight of 356kD and consisted mainly of mannose, xylose, galactose and glucose at a molar ratio 5.9:2.4:1:1.1. The structural assignment of TSP-II was carried out using fourier transform infrared spectroscopy (FTIR) analysis, periodate oxidation-smith degradation, partial hydrolysis with acid, methylation analysis and nuclear magnetic resonance (NMR) studies, and the repeating unit of TSP-II was thus determined. The result indicated that →3)-α-d-Manp-(1→, →2)-α-d-Xylp-(1→, →6)-α-d-Glcp-(1→ and →3)-α-d-Galp-(1→ formed the major components of the main-chain structure, and TSP-II was a non-branched polysaccharide. Transmission electron microscopy (TEM) analysis revealed a primary non-branched and entangled state in its microstructure. TSP-II had higher scavenging activities on hydroxyl radical (EC50=0.088mg/ml) and superoxide radical (EC50=0.127mg/ml) than Vitamin C (Vc).

Structure elucidation of a major fucopyranose-rich heteropolysaccharide (STP-II) from Sargassum thunbergii.

A crude polysaccharide was extracted from the edible algae S. thunbergii. DEAE-Sepharose CL-6B column chromatography was used to separate and purify a major polysaccharide STP-II (63.75%) from the crude polysaccharide. STP-II was found to be a homogeneous polysaccharide with a single peak by high-performance size-exclusion chromatography with a Sugar KS-804 column, have a molecular weight of 550 kD, and consist mainly of fucose, xylose, galactose, glucose and glucuronic acid. The structural assignment of STP-II was carried out using Fourier transform infrared spectroscopy analysis, periodate oxidation-smith degradation, partial hydrolysis with acid, methylation analysis and nuclear magnetic resonance studies, and the repeating unit of STP-II was thus determined. The result indicated that (1→3)-linked-fucose, (1→3)-linked-xylose and (1→3)-linked-galactose formed the major components of the main-chain structure, and the branch ratios were 17.5%. The branching and terminal residues were (1→2)-linked-glucuronic acid, (1→4)-linked-glucose, (1→)-linked-xylose and (1→)-linked-4-O-acetyl-glucose, respectively.

Extraction Optimization, Characterization and Bioactivities of a Major Polysaccharide from Sargassum thunbergii.

Sargassum thunbergii is a kind of natural edible algae. STP (S. thunbergii polysaccharides) was considered as the main bioactive compounds in S. thunbergii. To obtain the optimal processing conditions for maximum total sugar yield, single factor investigation and response surface methodology (RSM) were employed. The optimal processing conditions were as follows: liquid to solid ratio 120 mL/g, extraction time 210 min, extraction temperature 97°C. The experimental yield 7.53% under optimized conditions was closely agreed with the predicted yield 7.85% of the model. The major polysaccharide fraction from S. thunbergii (named STP-II) was purified by DEAE-Sepharose CL-6B column chromatography. High-performance size-exclusion chromatography (HPSEC), gas chromatography (GC) and high-performance liquid chromatography (HPLC) were used to identify its characterizations, and in vitro antioxidant assays and cytotoxicity assays were used to research its bioactivities. The purified fraction STP-II (63.75%) was a single peak in HPSEC with Sugar KS-804 column, had a molecular weight of 550KD, and comprised mainly of fucose, xylose, galactose, glucose and glucuronic acid. STP-II had higher scavenging activities on hydroxyl radical (76.72% at 0.7 mg/mL) and superoxide radical (95.17% at 2 mg/mL) than Vitamin C (Vc). STP-II also exhibited the capability of anti-proliferation in Caco-2 cells. STP-II possessed good antioxidant and inhibitory activity against human colon cancer Caco-2 cells in vitro and could be explored as novel natural functional food.

Suppression of c-Myc is involved in multi-walled carbon nanotubes' down-regulation of ATP-binding cassette transporters in human colon adenocarcinoma cells.

Over-expression of ATP-binding cassette (ABC) transporters, a large family of integral membrane proteins that decrease cellular drug uptake and accumulation by active extrusion, is one of the major causes of cancer multi-drug resistance (MDR) that frequently leads to failure of chemotherapy. Carbon nanotubes (CNTs)-based drug delivery devices hold great promise in enhancing the efficacy of cancer chemotherapy. However, CNTs' effects on the ABC transporters remain under-investigated. In this study, we found that multiwalled carbon nanotubes (MWCNTs) reduced transport activity and expression of ABC transporters including ABCB1/Pgp and ABCC4/MRP4 in human colon adenocarcinoma Caco-2 cells. Proto-oncogene c-Myc, which directly regulates ABC gene expression, was concurrently decreased in MWCNT-treated cells and forced over-expression of c-Myc reversed MWCNTs' inhibitory effects on ABCB1 and ABCC4 expression. MWCNT-cell membrane interaction and cell membrane oxidative damage were observed. However, antioxidants such as vitamin C, ß-mecaptoethanol and dimethylthiourea failed to antagonize MWCNTs' down-regulation of ABC transporters. These data suggest that MWCNTs may act on c-Myc, but not through oxidative stress, to down-regulate ABC transporter expression. Our findings thus shed light on CNTs' novel cellular effects that may be utilized to develop CNTs-based drug delivery devices to overcome ABC transporter-mediated cancer chemoresistance.

[Evaluation of the effect of early postoperative aural/oral rehabilitation of prelingual deaf children with cochlear implants].

OBJECTIVE: To evaluate the effect of aural/oral rehabilitation in the prelingual deaf children with cochlear implants, analyze the relationship between the age at the time of surgery and the rehabilitation effect, and explore the law of aural/oral rehabilitation in the prelingual deaf children after cochlear implantation. METHOD: Prelingual deaf children with cochlear implants were divided by age into 1.3-2.9 group (17 cases), 3.0-4.9 group(14 cases)and 5.0-7.9 group (26 cases). All the children were evaluated by CAP and SIR questionnaires 3 months, 6 months, 9 months and 12 months after the surgery. RESULT: The scores of CAP and SIR in different age groups were all increased with time after cochlear implantation. The score of CAP in 1.3-2.9 group rose the fastest, which was lowest at the end of the 3rd month and was highest at the end of the 12th month. There were no differences between the CAP scores of 1.3-2.9 group and 5.0-7.9 group in the later test. The score of SIR rose the fastest in 1.3-2.9 group, which was lowest at the end of the 3rd month and highest at the end of the 12th month and rose the slowest in 5.0-7.9 group, which was lower than the other groups at the end of the 12th month. CONCLUSION: Within one year after cochlear implantation, the younger the age, the better the effect of aural/oral rehabilitation.