DNAzyme-Mediated Biodeposition Coupling Adjustable Cascade Electric Fields for Photoelectrochemical Telomerase Activity Monitoring.

Telomerase, as a specialized reverse transcriptase, plays a vital role in early cancer diagnostics and prognosis; thus, developing efficient sensing technologies is of vital importance. Herein, an innovative "signal-on-off" photoelectrochemical (PEC) sensing platform was developed for ultrasensitive evaluation of telomerase activity based on an electron-transfer tunneling distance regulation strategy and DNAzyme-triggerable biocatalytic precipitation. Concretely, cascade internal electric fields between CuInS2 quantum dots (QDs), graphitic carbon nitride nanosheets (g-C3N4 NSs), and TiO2 nanorod arrays (NRAs) were developed to realize cascade electron extraction and hole transfer. Enabled by such a design, an effective "signal-on" state to gain a progressively enhanced PEC output was designed by suppressing the photogenerated electron-hole pair recombination. With the introduction of hairpin probe H2 and the subsequent extension of the primer sequence driven by the target telomerase, the CuInS2 QDs labeled with hairpin probe H1 were programmatically unfolded, resulting in CuInS2 QDs' close proximity to the working electrode away from the cascade interface, accompanied by the formation of G-quadruplex/hemin complexes. The gradual undermining of tunneling distance and implantation of DNAzyme-initiating biocatalytic precipitation tremendously induced the sluggish migration kinetics of the photoinduced charge, accompanied by the photocurrent intensity decrement, leading to the "signal-off" state. Under optimized conditions, the as-prepared PEC biosensor realizes ultrasensitive detection of telomerase activity from 10 to 105 cell·mL-1 with a detection limitation of 3 cells·mL-1. As a proof of concept, this well-designed method provides new insights into signal amplification for telomerase activity evaluation and also presents promising potential for further development in drug screening, healthcare diagnostics, and biological assays.

Application of tea polyphenols as additives in brown fermented milk: Potential analysis of mitigating Maillard reaction products.

Brown fermented milk (BFM) is favored by consumers in the dairy market for its unique burnt flavor and brown color. However, Maillard reaction products (MRP) from high-temperature baking are also noteworthy. In this study, tea polyphenols (TP) were initially developed as potential inhibitors of MRP formation in BFM. The results showed that the flavor profile of BFM did not change after adding 0.08% (wt/wt) of TP, and its inhibition rates on 5-hydroxymethyl-2-furaldehyde (5-HMF), glyoxal (GO), methylglyoxal (MGO), Nε-carboxymethyl lysine (CML), and Nε-carboxyethyl lysine (CEL) were 60.8%, 27.12%, 23.44%, 57.7%, and 31.28%, respectively. After 21 d of storage, the levels of 5-HMF, GO, MGO, CML, and CEL in BFM with TP were 46.3%, 9.7%, 20.6%, 5.2%, and 24.7% lower than the control group, respectively. Moreover, a smaller change occurred in their color and the browning index was lower than that of the control group. The significance of this study was to develop TP as additives to inhibit the production of MRP in brown fermented yogurt without changing color and flavors, thereby making dairy products safer for consumers.

The effect of vegetable oil pre-emulsified with whey protein and pectin on physicochemical properties and microstructure of low-fat yogurt.

The effects of whey protein isolate (WPI)-pectin pre-emulsified vegetable oil on the physicochemical properties and microstructure of low-fat yogurt (LFY) were investigated by particle size distribution, water-holding capacity (WHC), texture, rheology, electron microscopy, storage stability, and sensory analysis. The vegetable oil was pre-emulsified into two types of emulsions, a mixed emulsion (ME: WPI-pectin complexes were adsorbed directly at the interface) and a bilayer emulsion (BE: Pectin was added to a previously established WPI-stabilized interface). The results showed that yogurts added with pre-emulsified vegetable oil (ME-Y, BE-Y) had significantly better quality than LFY, with better WHC, textural properties, rheological properties, and storage stability. The average particle size of ME (11.96 µm) was larger than that of BE (10.23 µm). The consistency of yogurt added with ME (ME-Y) was significantly higher than that of yogurt added with BE (BE-Y), at 2359.10 and 2181.12 g s, respectively. Meanwhile, ME-Y exhibited storage stability similar to full-fat control (FFY) and higher sensory scores. Interestingly, the WHC of BE-Y (49.03%) was higher than that of ME-Y (45.63%). In addition, WPI + Pectin-Y exhibited higher WHC (53.81%) and consistency (2518.73 g s) compared to ME-Y and BE-Y, but the particle size distribution was not uniform, and the direct addition of WPI, pectin, and oil had no positive effect on improving the rheological properties of yogurt. Overall, the addition of WPI-pectin pre-emulsified vegetable oil improved the quality of LFY. These findings are particularly relevant for the production of higher quality LFY.

Application of whey protein emulsion gel microparticles as fat replacers in low-fat yogurt: Applicability of vegetable oil as the oil phase.

Low-fat, healthy yogurt is becoming increasingly favored by consumers. In the present study, whey protein emulsion gel microparticles were used to improve the quality of low-fat yogurt, and the effects of vegetable oil emulsion gel as a fat substitute on the qualities of low-fat yogurt were investigated, expecting to obtain healthier and even more excellent quality low-fat yogurt by applying a new method. First, emulsion gel microparticles were prepared, and then particle size distribution of emulsion gel and water holding capacity (WHC), textural properties, rheological properties, microstructure, storage stability, and sensory evaluation of yogurt were carried out. The results showed that yogurt with emulsion gel had significantly superior qualities than yogurt made with skim milk powder, with better WHC, textural properties, rheological properties, and storage stability. The average particle size of whey protein-vegetable oil emulsion gel microparticles was significantly larger than that of whey protein-milk fat emulsion gel microparticles, and the larger particle size affected the structural stability of yogurt. The WHC of yogurt made with whey protein-vegetable oil emulsion gel microparticles (V-EY) was lower (40.41%) than that of yogurt made with whey protein-milk fat emulsion gel microparticles (M-EY; 42.81%), and the texture results also showed that the hardness, consistency, and viscosity index of V-EY were inferior to these of M-EY, whereas no significant differences were found in the cohesiveness. Interestingly, the microstructure of V-EY was relatively flatter, with more and finer network branching. The whey separation between V-EY and M-EY also did not show significant differences during the 14 d of storage. Compared with yogurt made with whey protein, vegetable oil, and skim milk powder, the structure of V-EY remained relatively stable and had no cracks after 14 d of storage. The sensory evaluation results found that the total score of V-EY (62) was only lower than M-EY (65) and significantly higher than that of yogurt made with skim milk powder. The emulsion gel addition improved the sensory qualities of yogurt. Whey protein emulsion gel microparticles prepared from vegetable oil can be applied to low-fat yogurt to replace fat and improve texture and sensory defects associated with fat reduction.

Inhibitory effect of tanshinone IIA, resveratrol and silibinin on enterovirus 68 production through inhibiting ATM and DNA-PK pathway.

BACKGROUND: Human enterovirus 68 (EV68) is a primary etiological agent for respiratory illnesses, while no effective drug has yet used in clinics largely because the pathogenesis of EV68 is not clear. DNA damage response (DDR) responds to cellular DNA breaks and is also involved in viral replication. Three DDR pathways includes ataxia telangiectasia mutated (ATM), ATM and Rad3-related (ATR), and DNA-dependent protein kinase (DNA-PK). Natural products proved to be an excellent source for the discovery and isolation of novel antivirals. Among them, tanshinone IIA, resveratrol, silibinin, rutin and quercetin are reported to target DDR, therefore their roles in anti-EV68 are investigated in this study. PURPOSE: This study investigated the anti-EV68 ability of various natural compounds related to DDR. STUDY DESIGN AND METHODS: The methods include cell counting, flow cytometry, western blot, Immunofluorescence staining, comet assays, quantitative real-time RT PCR and short interfering RNAs (siRNAs) for analysis of cell number, cell cycle, protein expression, protein location, DNA damage, mRNA level and knock down target gene, respectively. RESULTS: EV68 infection induced DDR. Down-regulation or inhibition of ATM or DNA-PK lowered DDR in EV68-infected cells and mitigated viral protein expression, however, down-regulation or inhibition of ATR unexpectedly up-regulated DDR, and promoted viral protein expression. Meanwhile tanshinone IIA, resveratrol, and silibinin inhibited ATM and/or DNA-PK activation and decreased viral proliferation, while rutin and quercetin inhibited ATR activation and promoted viral production. The role of them in ATM, DNA-PK and ATR activation was consistent with previous reports. CONCLUSION: Tanshinone IIA, resveratrol and silibinin inhibited EV68 proliferation through inhibiting ATM and/or DNA-PK activation, and they were effective anti-EV68 candidates.

A Target-Driven Self-Feedback Paper-Based Photoelectrochemical Sensing Platform for Ultrasensitive Detection of Ochratoxin A with an In2S3/WO3 Heterojunction Structure.

Currently, developing versatile, easy-to-operate, and effective signal amplification strategies hold great promise in photoelectrochemical (PEC) biosensing. Herein, an ultrasensitive polyvinylpyrrolidone-treated In2S3/WO3 (In2S3-P/WO3)-functionalized paper-based PEC sensor was established for sensing ochratoxin A (OTA) based on a target-driven self-feedback (TDSF) mechanism enabled by a dual cycling tactic of PEC chemical-chemical (PECCC) redox and exonuclease III (Exo III)-assisted complementary DNA. The In2S3-P/WO3 heterojunction structure with 3D open-structure and regulable topology was initially in situ grown on Au nanoparticle-functionalized cellulose paper, which was served as a universal signal transducer to directly record photocurrent signals without complicated electrode modification, endowing the paper chip with admirable anti-interference ability and unexceptionable photoelectric conversion efficiency. With the assistance of Exo III-assisted cycling process, a trace amount of OTA could trigger substantial signal reporter ascorbic acid (AA) generated by the enzymatic catalysis of alkaline phosphatase, which could effectively provoke the PECCC redox cycling among the tris(2-carboxyethyl)phosphine acid, AA, and ferrocenecarboxylic at the In2S3-P/WO3 photoelectrode, initiating TDSF signal amplification. Based on the TDSF process induced by the Exo III-assisted recycling and PECCC redox cycling strategy, the developed paper-based PEC biosensor realized ultrasensitive determination of OTA with persuasive selectivity, high stability, and excellent reproducibility. It is believed that the proposed paper-based PEC sensing platform exhibited enormous potential for the detection of other targets in bioanalysis and clinical diagnosis.

Paper-Based Constant Potential Electrochemiluminescence Sensing Platform with Black Phosphorus as a Luminophore Enabled by a Perovskite Solar Cell.

Exploring efficient luminophores in the electrochemiluminescence (ECL) system is highly desired to pursue a sensitive ECL sensing platform. Herein, the black phosphorus nanosheets (BP NSs) with excellent ECL properties are investigated and serve as the luminophore with the coreactant of peroxydisulfate (S2O82-) solution. Moreover, owing to the overlapping of emission and absorbance spectra, effective resonance energy transfer (RET) is realized between the BP NSs and the introduced Au nanoparticles. In order to achieve the portable and miniaturized developing trends for the paper-based ECL sensing platform, a paper-based perovskite solar cell (PSC) device is designed to act as the power source to replace the commonly utilized expensive and cumbersome electrochemical workstation. Benefiting from that, a PSC driven paper-based constant potential ECL-RET sensing platform is constructed, thereby realizing sensitive microRNAs (miRNAs) detection. What's more, to attain the preferable analytical performance, the duplex-specific nuclease (DSN) is also introduced to assist the target recycling signal amplification strategy. Based on this, highly sensitive detection of miRNA-107 with a range from 0.1 pM to 15 nM is achieved by this designed sensing platform. Most importantly, this work not only pioneers a precedent for developing a high-sensitivity PSC triggered ECL sensing platform but also explores the application prospect of BP nanomaterial in the field of bioanalysis.

AgInSe2-Sensitized ZnO Nanoflower Wide-Spectrum Response Photoelectrochemical/Visual Sensing Platform via Au@Nanorod-Anchored CeO2 Octahedron Regulated Signal.

Herein an ultrasensitive photoelectrochemical (PEC)/visual biosensor coupled with a multiple signal amplification strategy was proposed for the detection of nucleic acids. The initial signal amplification was achieved via ternary AgInSe2 quantum dot (QD)-sensitized ZnO nanoflowers (ZnO NFs) to form an excellent photoelectric layer. A gold-modified nanorod-anchored CeO2 (Au@NR-CeO2) octahedron was introduced as a multifunctional signal regulator via the formation of triple helix molecules. The Au@NR-CeO2 octahedron could not only quench the photocurrent signal due to the competitive capture of photon energy and electron donors with the photoelectric layer but could also act like a peroxidase to catalyze the formation of mimetic enzymatic catalytic precipitation (MECP) on the surface of the photoelectric layer. Furthermore, the steric hindrance effect from the Au@NR-CeO2 octahedron further reduced the output of the photocurrent signal. After incubation with t-DNA, the triple helix conformation was disassembled and the Au@NR-CeO2 octahedron was released from the electrode surface, leading to the significant increase of photocurrent signal. Meanwhile, the released Au@NR-CeO2 octahedron could flow into the colorimetric area of the lab-on-paper device to catalyze the occurrence of the color reaction, achieving a visual detection for t-DNA. On the basis of the multiple signal amplification strategy, t-DNA was detected specifically with a lower limit of detection of 0.28 fM and a wider linear range from 0.5 fM to 50 nM. The proposed method has the potential utility to detect a variety of nucleic acids and biomarkers.

The combined effect of oleonuezhenide and wedelolactone on proliferation and osteoblastogenesis of bone marrow mesenchymal stem cells.

BACKGROUND: Regulation of the survival and differentiation of bone marrow mesenchymal stem cells is an essential consideration in the development of targeted drugs for treatment of osteoporosis. PURPOSE: The present study aimed to evaluate the combined effect of wedelolactone and oleonuezhenide, two compounds from Chinese formula Er-Zhi-Wan, on osteoblastogenesis and the underlying molecular mechanisms. METHODS: MTT assay was taken to evaluate cell proliferation. The alkaline phosphatase (ALP) activity assay was used to determine the activity of ALP. Alizarin red S (ARS) staining was taken to indicate the intensity of the calcium deposits. Quantitative real-time PCR and Western blot were performed to the levels of Runx2, Osteocalcin, and Osterix expression in mouse bone marrow mesenchymal stem cells (BMSCs). Ovariectomized mouse model and bone histomorphometric analysis were also used to research the effects of wedelolactone and oleonuezhenide on bone loss caused by ovariectomy. RESULTS: Wedelolactone combined with oleonuezhenide enhanced osteoblast differentiation and bone mineralization. Osteoblastogenesis-related marker genes including osteocalcin, Runx2, and osteorix were upregulated in the presence of wedelolactone and oleonuezhenide. At the molecular level, oleonuezhenide did not affect GSK-3ß phosphorylation induced by wedelolactone, but elevated casein kinase 2-alpha (CK2α) expression, resulting in ß-catenin and Runx2 nuclear translocation. In addition, 30 µM wedelolactone-induced cytotoxicity in bone marrow mesenchymal stem cells was relieved by 9 µM oleonuezhenide. These cells were protected by oleonuezhenide and maintained osteoblastic activity. Oleonuezhenide increased Wnt5a and CK2α expression. Wedelolactone-reduced extracellular signal-regulated kinase (ERK) phosphorylation was reversed by oleonuezhenide. In ovariectomized mice, administration of wedelolactone and oleonuezhenide prevented ovariectomy-induced bone loss by enhancing osteoblastic activity. CONCLUSION: These results suggested that oleonuezhenide enhanced the effects of wedelolactone on osteoblastogenesis. These two compounds could be developed as a combined therapeutic agent for osteoporosis.

The use of of inulin, maltitol and lecithin as fat replacers and plasticizers in a model reduced-fat mozzarella cheese-like product.

BACKGROUND: Mono-, di- and oligosaccharides, polyhydric alcohols and lipids are three main types of plasticizers used to process food materials. In the present study, inulin, maltitol and lecithin were selected as representative oligosaccharide, polyhydric alcohol and lipid fat replacers, respectively. Their effects on the physicochemical properties of reduced-fat mozzarella cheese were evaluated. RESULTS: Lecithin reduced the hardness and increased the degree of free oil released. Inulin and lecithin decreased the hydrophobic interaction of reduced-fat cheese. Maltitol improved the elasticity of the reduced-fat cheese and increased the hydrophobic interaction within the casein matrix. Maltitol-added cheese had a lower glass transition temperature (Tg ) than the other cheeses. Maltitol significantly improved the stretchability of the reduced-fat cheese. CONCLUSION: The results obtained in the present study suggest that maltitol is an effective fat replacer in reduced-fat mozzarella cheese and might enhance the cheese's functional properties. The Tg of cheese was related to the water and fat content, fat replacer addition and cross-linking degree of casein. The relationship between Tg and the physicochemical properties of cheese will be studied in further research. © 2019 Society of Chemical Industry.

Effect of ingredients from Chinese herbs on enterovirus D68 production.

Human enterovirus 68 (EVD68) is a primary causative agent for respiratory illness worldwide. Until now, there has been no available medication for treating EVD68-related diseases. Rheum emodin, artemisinin, astragaloside, pseudolaric acid B, oridonin, and erianin are natural extracts from Chinese herbs that have traditionally been used for the treatment and prevention of epidemic diseases. Our results showed that pseudolaric acid B protected cells from EVD68-induced cytopathic effects and decreased viral production. However, the same effects were not observed with rheum emodin, astragaloside, or artemisinin. Pseudolaric acid B inhibited EVD68 production by manipulating the host cell cycle in G2/M phase. Further, either oridonin or erianin related G2/M arrest also inhibited viral production. Due to inducing G2/M phase arrest, pseudolaric acid B, oridonin, and erianin might be good candidates for inhibiting EVD68 production, and Chinese herbs with natural compounds inducing G2/M arrest should be considered for the treatment of EVD68-related diseases.

Herba Artemisiae Capillaris Extract Prevents the Development of Streptozotocin-Induced Diabetic Nephropathy of Rat.

Diabetic nephropathy (DN) is a major cause of end-stage renal disease throughout the world; until now there is no specific drug available. In this work, we use herba artemisiae capillaris extract (HACE) to alleviate renal fibrosis characterized by the excessive accumulation of extracellular matrix (ECM) in rats, aiming to investigate the protective effect of the HACE on DN. We found that the intragastric treatment of high-dose HACE could reverse the effect of streptozotocin not only to decrease the level of blood glucose and blood lipid in different degree but also further to improve renal functions. It is worth mentioning that the effect of HACE treatment was comparable to the positive drug benazepril. Moreover, we found that HACE treatment could on one hand inhibit oxidative stress in DN rats through regulating enzymatic activity for scavenging reactive oxygen species and on the other hand increase the ECM degradation through regulating the activity of metalloproteinase-2 (MMP-2) and the expression of tissue transglutaminase (tTG), which explained why HACE treatment inhibited ECM accumulation. On the basis of above experimental results, we conclude that HACE prevents DN development in a streptozotocin-induced DN rat model, and HACE is a promising candidate to cure DN in clinic.

Pseudolaric acid B inhibits neuroglioma cell proliferation through DNA damage response.

Human neuroglioma is one of the most common malignant intracranial tumors in neurosurgery, and accounts for more than 50% of all brain cancer cases. Thus, a clinically effective drug with which to treat neuroglioma is urgently required. Pseudolaric acid B (PAB), a diterpene acid isolated from the root and trunk bark of Pseudolarix kaempferi Gordon (Pinaceae), was found to inhibit cell growth in a variety of cancer cell lines, but to date the effect of PAB on neuroglioma remains unclear. MTT analysis confirmed that PAB inhibited neuroglioma A172 cell growth in a time- and dose-dependent manner. In addition, PAB influenced the aggregation of tubulin in A172 cells. Meanwhile following PAB treatment, a higher percentage of cells accumulated in the G2/M phase from 12 to 48 h, while at 36 h, cell cycle slippage into the G0/G1 phase, and at 48 h, slippage into the S phase was observed using flow cytometric analysis. Corresponding protein expression was consistent with the cell cycle alteration as detected by western blotting, and it was speculated that cell cycle slippage was related to reduced effectiveness of PAB which warrants further investigation. Meanwhile PAB induced cell death by regulating p38, ERK and JNK expression and activating the DNA damage response. Therefore, PAB plays an antitumor role in A172 cells, and may be a candidate drug for neuroglioma therapy.

Diabetes reversal by inhibition of the low-molecular-weight tyrosine phosphatase.

Obesity-associated insulin resistance plays a central role in type 2 diabetes. As such, tyrosine phosphatases that dephosphorylate the insulin receptor (IR) are potential therapeutic targets. The low-molecular-weight protein tyrosine phosphatase (LMPTP) is a proposed IR phosphatase, yet its role in insulin signaling in vivo has not been defined. Here we show that global and liver-specific LMPTP deletion protects mice from high-fat diet-induced diabetes without affecting body weight. To examine the role of the catalytic activity of LMPTP, we developed a small-molecule inhibitor with a novel uncompetitive mechanism, a unique binding site at the opening of the catalytic pocket, and an exquisite selectivity over other phosphatases. This inhibitor is orally bioavailable, and it increases liver IR phosphorylation in vivo and reverses high-fat diet-induced diabetes. Our findings suggest that LMPTP is a key promoter of insulin resistance and that LMPTP inhibitors would be beneficial for treating type 2 diabetes.

Effect of Renshen Pingfei Decoction, a traditional Chinese prescription, on IPF induced by Bleomycin in rats and regulation of TGF-ß1/Smad3.

AIM OF THE STUDY: Idiopathic pulmonary fibrosis (IPF), one of the clinical common diseases, shares similar pathogenesis with ancient disease "Feibi" in Chinese medicine, Renshen pingfei decoction (RPFS), a classical prescription, was commonly used in treating Feibi. In the current study, the protective role of RPFS in rats model of IPF and the mechanism via regulation of TGF-ß1/Smad3, were evaluated and explored. METHODS: The chemicals of RPFS were analyzed by UPLC-QTOF-MS. Under the optimized chromatographic and MS condition, the major components in RPFS were well separated and detected. An IPF model was established in rats which were induced with Bleomycin (BLM). After treated with corresponding medicine for 7 days, 14 days, 21 days and 28 days respectively, lung function of rats were measured; peripheral blood and bronchoalveolar lavage fluid (BALF) were assessed; histopathological changes and homogenate of lung tissue were detected; TGF-ß1 and Smad3 mRNA and protein expressions in lung tissue were examined as well. RESULTS: 43 signal peaks of chemical components in RPFS were identified by UPLC-QTOF-MS method. Compared with model group, RPFS group exerted significant effects on IPF model rats in improving lung function and decreasing HYP content of lung tissue (P<0.01), reducing the level of TGF-ß1 and NFκB in BALF (P<0.05), decreasing SOD and MDA level in serum (P<0.01), as well as down-regulating TGF-ß1 and Smad3 mRNA and protein expressions of lung tissue (P<0.01). CONCLUSION: RPFS could reduce the lung injury and fibrosis degree and improve lung function of IPF model rats. The protective role might mediated by down-regulating TGF-ß1/Smad3 signaling pathway.

[On the Commonness of San'ao Decoction and Its Analogous Formulas in Facilitating Fei].

San'ao Decoction (SD) and its analogous formulas derived in the following generations are common used prescriptions for treating pulmonary diseases with principal symptoms such as cough and asthma. They are usually compatible with Chinese herbs for facilitating Fei, dispelling wind, resolving phlegm and fluid retention. Material bases in these formulas are mainly derived from Chinese drugs, but dissolution contents of active components are changed and new components are produced after compatibility. By multilevel effect evaluation, these analogous formulas all have commonness in ventilating Fei and superiorities of evidence-based derivation. The effect pathway of commonness was involved in cell structure protection, anti-inflammation, antioxidant, and immunoregulation.

Graphene-palladium nanowires based electrochemical sensor using ZnFe2O4-graphene quantum dots as an effective peroxidase mimic.

We proposed an electrochemical DNA sensor by using peroxidase-like magnetic ZnFe2O4-graphene quantum dots (ZnFe2O4/GQDs) nanohybrid as a mimic enzymatic label. Aminated graphene and Pd nanowires were successively modified on glassy carbon electrode, which improved the electronic transfer rate as well as increased the amount of immobilized capture ssDNA (S1). The nanohybrid ZnFe2O4/GQDs was prepared by assembling the GQDs on the surface of ZnFe2O4 through a photo-Fenton reaction, which was not only used as a mimic enzyme but also as a carrier to label complementary ssDNA (S3). By synergistically integrating highly catalytically activity of nano-sized GQDs and ZnFe2O4, the nanohybrid possessed highly-efficient peroxidase-like catalytic activity which could produce a large current toward the reduction of H2O2 for signal amplification. Thionine was used as an excellent electron mediator. Compared with traditional enzyme labels, the mimic enzyme ZnFe2O4/GQDs exhibited many advantages such as environment friendly and better stability. Under the optimal conditions, the approach provided a wide linear range from 10(-16) to 5×10(-9) M and low detection limit of 6.2×10(-17) M. The remarkable high catalytic capability could allow the nanohybrid to replace conventional peroxidase-based assay systems. The new, robust and convenient assay systems can be widely utilized for the identification of other target molecules.

Identification of amino acid and glutathione N-conjugates of toosendanin: bioactivation of the furan ring mediated by CYP3A4.

Toosendanin (TSN) is a hepatotoxic triterpenoid extracted from Melia toosendan Sieb et Zucc. Considering that TSN contains the structural alert of the furan ring, it is believed that bioactivation of TSN may be responsible for its toxicity. Herein, the bioactivation potential and metabolism profiles of TSN were investigated. After an oral administration of 10 mg/kg TSN to rats, esterolysis and conjugation with amino acids were identified as the main metabolic pathways. The same types of conjugates were detected in liver microsomes in an NADPH-dependent manner. According to the remaining amount of the parent drug, the reactivity of trapping reagents with TSN reactive metabolites was sorted in a decreasing order of N(α)-(tert-butoxycarbonyl)-l-lysine (Boc-Lys) > alanine, lysine, taurine, phenylalanine, serine, glutamic acid, glycine, and glutathione (GSH) > cysteine. No conjugates were observed in NADPH and N-acetyl cysteine (NAC)-supplemented human liver microsomal incubations. Further phenotyping studies and the chemical synthesis of the major conjugated standards proved that TSN was bioactivated by CYP3A4 and yielded a cis-butene-1,4-dial intermediate, which was prone to undergo 1,2-addition with the amino group of amino acids and GSH to form 3-pyrroline-2-one adducts. The sulfydryl group of GSH also attacked the intermediate and yielded S-conjugates by 1,4- or 1,2-addition, which would form pyrrole conjugates by further reacting with the amino group. Compared to the well-recognized S-conjugation of the furan ring, N-conjugation with multiple amino acids and GSH played a more important part in the elimination of reactive metabolites of TSN. The significance of these conjugates requires further investigation.

Using "dioscorea batatas bean"-like silver nanoparticles based localized surface plasmon resonance to enhance the fluorescent signal of zinc oxide quantum dots in a DNA sensor.

We reported here the preparation of "dioscorea batatas bean"-like silver nanoparticles (AgNPs) and the unique structure provided the AgNPs good localized surface plasmon resonance (LSPR) property. In addition, zinc oxide quantum dots (ZnO QDs) were also synthesized and found with good fluorescent property. Furthermore, the ZnO QDs decorated exfoliated graphene oxide (EGO-ZnO) was prepared via electrostatic interaction. The named nanomaterials were applied in a LSPR-induced fluorescent DNA sensor. To fabricate the DNA sensor, the EGO-ZnO was modified on the silica glass as the supporter for the capture probe ssDNA, and the complementary ssDNA was labeled on the surface of the AgNPs. After the hybridization step by step, the AgNPs was fastened on the surface of the EGO-ZnO, and the fluorescent intensity of the EGO-ZnO increased as a result. The prepared DNA sensor enabled the target ssDNA to be detected in the concentration range of 10(-19)-10(-14)M, and the limit of detection was 4.3 × 10(-20)M.

CD4⁺CD25⁺FOXP3⁺ T cells, Foxp3 gene and protein expression contribute to antiasthmatic effects of San'ao decoction in mice model of asthma.

OBJECTIVE: San'ao decoction (SAD) is a commonly used traditional combinatorial formula composed of Herba Ephedrae, Radix Glycyrrhizae and Amygdalus Communis Vas. Early studies showed that in the OVA sensitization asthmatic mice model its compatibility could lower airway reactivity and airway inflammatory cell infiltration. Based on the above results, this study mainly discussed San'ao decoction's immunomodulatory effects on Tregs. METHODS: UPLC-PDA-TOF-MS was applied to analyze chemicals of SAD, and under the optimized chromatographic and MS condition, the major components in SAD were well separated and detected within 22 min. An asthma model was established in BALB/c mice that were sensitized and challenged with ovalbumin. After 2 weeks' treatment, peripheral blood and bronchoalveolar lavage fluid (BALF) were assessed for inflammatory cell counts; histological change of lung tissue were detected; flow cytometry detection of splenic CD4(+)CD25(+)Foxp3(+) Treg cells of the mice were counted; Foxp3 expression in lung tissues were examined as well. RESULTS: 22 Peaks signal chemical components in SAD were identified by UPLC-QTO-MS method. In terms of the percentage of eosinophile in peripheral blood and bronchoalveolar lavage fluid (BALF), SAD groups were significantly lower (p<0.01) than model group. Compared with model group, lung histological changes of SAD groups were reduced; the proportion of CD4(+)CD25(+)Foxp3(+) Treg cells in CD4(+) cells of asthmatic mice also decreased; SAD significantly increased the proportion of CD4(+)CD25(+)Foxp3(+) Treg cells and promoted Foxp3 expression in a mouse model of asthma. CONCLUSION: These results suggest that the antiasthmatic effects of SAD are at least partially associated with CD4(+)CD25(+)Foxp3(+) Treg cells.