Silybin ameliorates hepatic lipid accumulation and modulates global metabolism in an NAFLD mouse model.

Silybin shows good effects against obesity and metabolic syndrome, but the systemic modulation effect of silybin has not been fully revealed. This study aims to investigate the metabolic regulation by silybin of nonalcoholic fatty liver disease (NAFLD). C57BL/6 J mice were fed a high-fat/high-cholesterol diet for 8 weeks and treated with silybin (50 or 100 mg/kg/day) and sodium tauroursodeoxycholate (TUDCA, 50 mg/kg/day) by gavage for the last 4 weeks. Blood biochemical indexes and hepatic lipid measurement as well as Oil red O staining of the liver were conducted to evaluate the model and the lipid-lowering effect of silybin and TUDCA. Furthermore, serum and liver samples were detected by a metabolomic platform based on gas chromatography-mass spectrometry (GC/MS). Multivariate/univariate data analysis and pathway analysis were used to investigate differential metabolites and metabolic pathways. The results showed that the mouse NAFLD model was established successfully and that silybin and TUDCA significantly lowered both serum and hepatic lipid accumulation. Metabolomic analysis of serum and liver showed that a high-fat/high-cholesterol diet caused abnormal metabolism of metabolites involved in lipid metabolism, polyol metabolism, amino acid metabolism, the urea cycle and the TCA cycle. Silybin and TUDCA treatment both reversed metabolic disorders caused by HFD feeding. In conclusion, a high-fat/high-cholesterol diet caused metabolic abnormalities in the serum and liver of mice, and silybin treatment improved hepatic lipid accumulation and modulated global metabolic pathways, which provided a possible explanation of its multiple target mechanism.

Curcumin inhibits hepatic stellate cell activation via suppression of succinate-associated HIF-1α induction.

PURPOSE: Aberrant succinate accumulation emerges as a unifying mechanism for inflammation and oxidative stress. This study aims to investigate whether curcumin ameliorates hepatic fibrosis via blocking succinate signaling. METHODS: We investigated the effects of curcumin on hepatic succinate accumulation and liver fibrosis in mice fed a high-fat diet (HFD). Meanwhile, we stimulated mouse primary hepatic stellate cells (HSCs) with succinate and observed the inhibitory effects of curcumin on succinate signaling. RESULTS: Oral administration of curcumin and metformin combated mitochondrial fatty acid oxidation and reduced hepatic succinate accumulation due to the inhibition of succinate dehydrogenase (SDH) activity and demonstrated inhibitory effect on hepatic fibrosis. In mouse primary HSCs, curcumin prevented succinate- and CoCl2-induced hypoxia-inducible transcription factor-1α (HIF-1α) induction via suppression of ROS production and effectively reduced gene expressions of Col1α, Col3α, fibronectin and TGF-ß1 with inflammation inhibition. Knockdown of HIF-1α with small interfering RNA blocked the action of succinate to induce HSCs activation, indicative of the essential role of HIF-1α in succinate signaling. CONCLUSIONS: Hepatic succinate accumulation served as a metabolic signal to promote liver fibrosis through HIF-1α induction. Curcumin reduced succinate accumulation by combating fatty acid oxidation and prevented HSCs activation by blocking succinate/HIF-1α signaling pathway.

Curcumin restrains hepatic glucose production by blocking cAMP/PKA signaling and reducing acetyl CoA accumulation in high-fat diet (HFD)-fed mice.

OBJECTIVE: This study is designed to investigate whether curcumin reduces excessive hepatic glucose production (HGP) via regulation of second messenger cAMP. METHODS: High-fat diet (HFD)-fed mice were orally administrated of metformin (200 mg/kg) or curcumin (50 mg/kg) daily for 10 weeks. Meanwhile, we stimulated mouse primary hepatocytes with palmitate (PA). RESULTS: Curcumin reduced hepatic cAMP accumulation by preserving PDE4B induction, thereby suppressing gluconeogenesis via blocking cAMP/PKA activation. Curcumin reduced lipid deposition by reducing free fatty acid uptake and prevented acetyl CoA accumulation by combating mitochondrial oxidation. As a result from inhibiting acetyl CoA accumulation, curcumin protected pyruvate dehydrogenase (PDH) activity and inhibited pyruvate carboxylase (PC), limiting the shift of mitochondrial pyruvate from oxidation to gluconeogenesis via the carboxylation. CONCLUSION: Curcumin reduced cAMP accumulation by preserving PDE4B activity and inhibited acetyl CoA production by reducing mitochondrial fatty acid oxidation, thereby restraining pyruvate-driven hepatic glucose production.

Silybin inhibits NLRP3 inflammasome assembly through the NAD+/SIRT2 pathway in mice with nonalcoholic fatty liver disease.

Silybin is one of the effective, traditional Chinese medicines used as a hepatoprotective agent in nonalcoholic fatty liver disease (NAFLD) therapy worldwide, and the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome has been recognized as an important factor involved in NAFLD development. However, little is known about the mechanisms of silybin in the regulation of high-fat diet (HFD)-induced liver inflammation. In our study, we found that silybin inhibited endoplasmic reticulum stress and NLRP3 inflammasome activation in the livers of HFD-fed mice and in cultured hepatocytes. Phosphorylation of inositol-requiring enzyme (IRE)1α and eIF2α, expression of thioredoxin-interacting protein and cleaved caspase-1, and release of IL-1ß were reduced by silybin. In addition, silybin inhibited the approach of calreticulin and translocase of outer membrane 20 (Tom20), prevented assembly of the NLRP3 inflammasome complex, and suppressed the accumulation of acetylated α-tubulin in the perinuclear region. Both MEC-17 and sirtuin 2 (SIRT2) were influenced by palmitate and silybin, whereas histone deacetylase 6 was not affected. In addition, supplementing NAD+ directly or increasing NAD+ concentration with silybin could maintain the activity of SIRT2. The anti-inflammatory effect of silybin was blocked by SIRT2 silencing or by the SIRT2 inhibitor AGK2, as evidenced by NLRP3/ASC colocalization, AC-α-tubulin expression, and IL-1ß release. These findings indicate that the NAD+/SIRT2 pathway is an important mediator through which silybin prevents NLRP3 inflammasome activation during NAFLD.-Zhang, B., Xu, D., She, L., Wang, Z., Yang, N., Sun, R., Zhang, Y., Yan, C., Wei, Q., Aa, J., Liu, B., Wang, G., Xie, Y. Silybin inhibits NLRP3 inflammasome assembly through the NAD+/SIRT2 pathway in mice with nonalcoholic fatty liver disease.

Nucleic acid quantification using nicking-displacement, rolling circle amplification and bio-bar-code mediated triple-amplification.

In the present study, an inductively-coupled plasma-mass spectrometry (ICP-MS)-based triple-amplification system, by combination of nicking-displacement, rolling circle amplification (RCA) and bio-bar-code probes, was fabricated for the detection of DNA target. By using this system, hepatitis B virus (HBV) DNA target down to 3.2×10(-17)M was detected by DNA probes labeled with Au nanoparticles (AuNPs). Single nucleotide polymorphisms in genes can also be effectively discriminated. In addition, we proved that this strategy is capable of detecting the target in complicated biological samples and holds great potential application in biomedical research.

A dual-amplified electrochemical detection of mRNA based on duplex-specific nuclease and bio-bar-code conjugates.

On the basis of strong preference for cleaving double-stranded DNA or DNA in DNA:RNA heteroduplexes of duplex-specific nuclease (DSN), a dual-amplified electrochemical detection of mRNA was developed in this article, by coupling the enhancement of DSN and bio-bar-code conjugates. Capture probe was linked with magnetic nanoparticles (MNPs) at its 5' end and bio-bar-code at its 3' end. In the presence of target surviving mRNA, all hybridized S1 strands were cleaved off the biosensor by the DSN, and the bio-bar-code probe with CdS nanoparticles (CdS NPs) was released into the solution. The metal sulfide nanoparticles were measured by anodic stripping voltammetry (ASV) subsequently. This assay exhibited high sensitivity and selectivity with a detection limit of 0.48fM. In addition, we proved that this simple and cost-effective strategy is capable of detecting the target in complicated biological samples and holds great potential application in biomedical research and clinical diagnostics.

Expression characteristics of FHIT, p53, BRCA2 and MLH1 in families with a history of oesophageal cancer in a region with a high incidence of oesophageal cancer.

The aim of the present study was to determine the changes to the expression levels of fragile histidine triad (FHIT), breast cancer type 2 susceptibility protein (BRCA2), MutL homolog 1 (MLH1) and tumour protein 53 (p53) exhibited by families with a history of oesophageal cancer in a region that has a high incidence of oesophageal cancer, and to determine the association of these changes with the cancer history of the families. Immunohistochemistry was used to detect the protein expression of FHIT, p53, BRCA2, and MLH1 in the excised specimens of cancer tissues from 74 oesophageal cancer patients (positive family history of oesophageal cancer [OCFH +], n=33; negative family history of oesophageal cancer [OCFH -], n=41) from a region with a high incidence of oesophageal cancer. The positive expression rates of FHIT (61%; 45/74), BRCA2 (50%; 37/74) and MLH1 (27%; 9/33) in the oesophageal cancer tissues were significantly lower than those in the healthy tissues adjacent to the cancer (97% [29/30], 87% [26/30] and 73% [25/41], respectively). A significant difference was identified between the positive expression rates (P<0.01). However, FHIT, p53, BRCA2 and MLH1 expression demonstrated no significant affect on clinicopathological changes, such as oesophageal cancerous tissue differentiation, the degree of infiltration and cancer cell metastasis. The FHIT, BRCA2 and MLH1 expression levels were identified to be significantly lower in the cancer tissues from OCFH + patients. This result indicates that the expression levels of FHIT, BRCA2, and MLH1 are important molecular indices of genetic susceptibility to oesophageal cancer.

A surface plasmon resonance assay coupled with a hybridization chain reaction for amplified detection of DNA and small molecules.

A surface plasmon resonance (SPR) detection system based on a hybridization chain reaction (HCR) was developed for amplified detection of DNA and small molecule with high sensitivity.

SC-514, a selective inhibitor of IKKß attenuates RANKL-induced osteoclastogenesis and NF-κB activation.

The RANKL-induced NF-κB signaling pathway is essential for osteoclastogenesis. This study aims to identify specific inhibitors targeting NF-κB signaling pathway, which might serve as useful small molecule inhibitors for the treatment and alleviation of osteoclast-mediated bone lytic diseases. By screening for compounds that selectively inhibit RANKL-induced NF-κB activation in RAW264.7 cells as monitored by luciferase reporter gene assay, we identified SC-514, a specific inhibitor of IKKß, as a candidate compound targeting osteoclastogenesis. SC-514 dose-dependently inhibits RANKL-induced osteoclastogenesis with an IC50 of <5µM. At high concentrations, SC-514 (≥12.5µM) induced apoptosis and caspase 3 activation in RAW264.7 cells. Moreover, SC-514 specifically suppressed NF-κB activity owing to delayed RANKL-induced degradation of IκBα and inhibition of p65 nuclear translocation. Taken together, our results indicate that SC-514 impairs RANKL-induced osteoclastogenesis and NF-κB activation. Thus, targeting IKKß by SC-514 presents as a potential treatment for osteoclast-related disorders such as osteoporosis and cancer-induced bone loss.

[Purification and characterization of a chitinase from Bombyx mori].

The importance of chitinases in the physiological and developmental processes of fungi and insects makes themselves and their inhibitors important targets for biological pesticides. A chitinase was isolated from Bombyx mori and purified to electrophoretic homogeneity by ammonium sulfate precipitation and Sephadex G-150 column chromatography. The molecular mass was estimated to be about 88 kDa by SDS-PAGE, while the K(m) was calculated to be 22.3 micromol/L. Moveover, the optimal reaction temperature was 45 degrees C, and the optimum pH was 6.0. The effect of metal ions and organic reagents on chitinase activity was investigated. The activity was enhanced by high concentration of Mn2+, while was strongly inhibited by Cu2+ and SDS. These results provide a basis for screening the chitinase-based biological pesticide.

Highly sensitive electrochemical detection of human telomerase activity based on bio-barcode method.

In the present study, an electrochemical method for highly sensitive detection of human telomerase activity was developed based on bio-barcode amplification assay. Telomerase was extracted from HeLa cells, then the extract was mixed with telomerase substrate (TS) primer to perform extension reaction. The extension product was hybridized with the capture DNA immobilized on the Au electrode and then reacted with the signal DNA on Au nanoparticles to form a sandwich hybridization mode. Electrochemical signals were generated by chronocoulometric interrogation of [Ru(NH(3))(6)](3+) that quantitatively binds to the DNA on Au nanoparticles via electrostatic interaction. This method can detect the telomerase activity from as little as 10 cultured cancer cells without the polymerase chain reaction (PCR) amplification of telomerase extension product.

3,3-Dimethyl-1-[5-(1H-1,2,4-triazol-1-yl-meth-yl)-1,3,4-thia-diazol-2-ylsulfan-yl]butan-2-one.

In the mol-ecule of the title compound, C(11)H(15)N(5)OS(2), the thia-diazole and triazole rings are not coplanar, the dihedral angle formed by their mean planes being 59.9 (2)°. The exocyclic S atom, and the methyl-ene, carbonyl, tert-butyl and one methyl carbon form an approximately planar zigzag chain, which makes a dihedral angle of 74.6 (1)° with the thia-diazole ring.

Synthesis and QSAR studies of novel triazole compounds containing thioamide as potential antifungal agents.

Eighteen novel triazole compounds containing thioamide were designed and synthesized. Their structures were confirmed by elemental analysis, (1)H NMR, IR, and MS. The title compounds exhibited certain antifungal activity. And the geometry structures of the title compounds were optimized by means of the density functional theory (DFT) method at B3LYP/6-31G( *) level. The quantitative structure-activity relationship (QSAR) of the title compounds was systematically investigated. A correlative equation between FA and DELH, V was well established by using the multiple linear regression (MLR).

Electrochemical polymerization of fluoranthene and characterization of its polymers.

A novel inherently conducting polymer, high-quality polyfluoranthene (PFA) film with electrical conductivity of 10(-2) S cm(-1), was first synthesized electrochemically by direct anodic oxidation of fluoranthene in a middle strong Lewis acid-boron trifluoride diethyl etherate. The oxidation potential onset of fluoranthene in this medium was measured to be only 1.07 V vs SCE, which was much lower than that in acetonitrile + 0.1 mol L(-1) tetrabutylammonium tetrafluoroborate (1.68 V vs SCE). This PFA film showed good redox activity and stability even in concentrated sulfuric acid. Moreover, the fluorescence properties of PFA were greatly improved in comparison with those of the monomer. Dedoped PFA films were partly soluble in polar solvents such as CH(2)Cl(2), acetone, tetrahedrofuran, and dimethyl sulfoxide. The structure and morphology of the polymer were investigated by UV-vis spectroscopy, infrared spectroscopy, and scanning electron microscopy, respectively. The results of quantum chemistry calculations of fluoranthene monomer and (1)H NMR spectroscopy of dedoped PFA films indicated that the polymerization mainly occurred at C((3)), C((4)), C((13)), and C((14)) positions.