Arg-liposome-amplified colorimetric immunoassay for selective and sensitive detection of cystatin C to predict acute kidney injury.

Cystatin C (Cys C) has been considered as a novel biomarker of kidney disease, which is thought to be a better indicator of glomerular filtration rate than creatinine (Scr) in the prediction of acute kidney injury (AKI). Hence, there is strong need to develop a precise, rapid and simple detection method for Cys C. Here we reported a Arg-liposome-amplified colorimetric immunoassay for the detection of Cys C to predict AKI. Cys C antibodies are conjugated on the surface of magnetic beads (MBs) and arginine (Arg)-loaded liposomes to form Ab1-MBs and Ab2-Arg-liposomes, respectively. When Ab1-MBs captured Cys C, Ab2-Arg-liposomes are added and incubated to form the immuno-sandwich complex. After magnetic separation, the surfactant Triton ×100 is added to damage the liposomes, leading to the release of Arg which can induce the gold nanoparticles aggregation. Therefore, the discoloration can be used for visual and quantitative detection of Cys C. Notably, the method has a linear relation in the range of 10-100 µg/L for Cys C with a limit of detection 4.32 µg/L, which is lower than some of the previous reports. In addition, the AKI mice serum samples were tested by the developed method, which were in good agreement with ELISA results. More intriguingly, the results of cisplatin induced acute kidney injury in mice showed that the method could be used to evaluate the protective effect of astragalus membranaceus (AM) on AKI by detecting Cys C in serum, providing a new strategy for screening renal protective drugs. Accordingly, a rapid and highly sensitive Cys C detection system was established with great potential for clinical diagnostics.

A nano-preparation approach to enable the delivery of daphnoretin to potentiate the therapeutical efficacy in hepatocellular cancer.

Daphnoretin (DAP), isolated from a traditional Chinese medicine Wikstroemia indica (Linn. C. A. Meyer), could induce apoptosis of hepatocellular cancer (HCC) and inhibit tumor growth. However, the application of DAP in cancer therapies was hampered because to its poor solubility. Herein, this study aimed to design an approach of double-targeted nano-preparation to enable the delivery of DAP to potentiate the therapeutical efficacy in liver cancer via glycyrrhetinic acid-polyethylene glycol-block-poly (D,L-lactic acid)/polyethylene glycol-block-poly (D,L-lactic acid)-DAP (GPP/PP-DAP). In particular, the purity of separated DAP was up to 98.12% for preparation research. GPP/PP-DAP was successfully prepared by the thin-film hydration method. Subsequently, the GPP/PP-DAP was optimized by univariate analysis and the response surface methodology, producing a stable and systemically injectable nano-preparation. Impressively, on the one hand, cytotoxicity studies showed that the IC50 of the GPP/PP-DAP was lower than that of free DAP. On the other hand, the GPP/PP-DAP was more likely to be endocytosed by HepG2 cells and targeted to the liver with orthotopic tumors, potentiating the therapeutical efficacy in HCC. Collectively, both in vitro and in vivo results indicated the excellent tumor inhibition and liver targeting of GPP/PP-DAP, suggesting the nano-preparation could serve as a potential drug delivery system for natural ingredients with anti-hepatoma activity to lay the theoretical foundation for clinical application.

Developing a novel and simple biosensor for Cystatin C as a fascinating marker of glomerular filtration rate with DNase I-aided recycling amplification strategy.

Cystatin C (Cys C) has been proposed as a fascinating glomerular filtration rate (GFR) marker for early detection of acute kidney injury and chronic kidney disease. However, most of traditional methods for Cys C detection are immunoassays, which was tedious to perform and unfriendly for economics. In this work, a novel and simple biosensor for the sensitive measurement of Cys C via DNase I-aided recycling amplification strategy was successfully constructed based on the graphene oxide (GO) and fluorophore-labelled aptamer, which can be used to the early prediction of kidney injury. The fluorescence of fluorophore-labelled aptamer was quenched by GO based on the Fluorescence Resonance Energy Transfer (FRET) and recovered with the existence of Cys C. In addition, the DNase I enzyme would digest the fluorophore-labelled aptamer and dissociate the Cys C to launch the next reaction, resulting in an increase of signal amplification. Hence, the limit of detection is found to be 0.16 ng mL-1, which is almost 3 times lower than that without DNase I. Consequently, the developed biosensor offers a novel approach towards simple and rapid detection of Cys C based on the integration of GO and aptamer. Conceivably, this strategy holds a wide scope in the application of numerous other analytes if corresponding aptamers are available.

In Vitro and In Vivo Anti-AChE and Antioxidative Effects of Schisandra chinensis Extract: A Potential Candidate for Alzheimer's Disease.

Acetylcholinesterase (AChE) inhibition and antioxidants are two common strategies for the treatment in the early stage of Alzheimer's Disease (AD). In this study, extracts from nine traditional Chinese medical (TCM) herbs were tested for anti-AChE activity by Ellman's microplate assay and cytotoxicity by CCK-8. Based on its excellent AChE inhibition effect and its lowest cytotoxicity, Schisandra chinensis (SC) extract was selected to do the mechanism research. SC extract protected pheochromocytoma (PC12) cells against H2O2-induced toxicity by improving the cell survival rate in a dose-dependent manner. And it also showed significant free radical (DPPH) scavenging activities, ferric reducing antioxidant power (FRAP), and 2,2'-Azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging. To confirm these results, the scopolamine-induced mice models were utilized in this study. Compared with the positive drug (piracetam), SC could also exhibit similar effects to alleviate the mice's cognitive deficits. Moreover, in the mice brain samples, the AChE activity and malondialdehyde (MDA) levels of SC-treatment group both showed a reverse as compared to model group. Taken together, these results all suggested that SC extract may be a potential therapeutic candidate for AD.

[A liquid chromatography-mass spectrometry-based metabolomic study on the changes of intracellular lipid metabolism regulated by Pokemon].

Pokemon, a transcriptional repressor, inhibits the transcription of tumor suppressor genes and promotes tumor formation by affecting chromatin recombination or binding directly to the tumor suppressor genes. In this study, the mechanism behind the Pokemon regulation of liver cancer cell metabolism was evaluated using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. Pokemon-overexpressing HL7702 cells were obtained by lipofection. The cells were collected at different time points after transfection and their intracellular metabolites were analyzed using an LC-MS-based metabolomic method. Based on the results of a multivariate statistical analysis, candidate metabolites with significant differences were selected, and 36 of them were confirmed by database and MS/MS analysis. These metabolites were primarily involved in lipid synthesis by KEGG database searches. Further analysis indicated that both the acetyl-coenzyme carboxylase and the fatty acid synthase were activated in the lipid synthesis pathway. The results show that Pokemon can affect cell metabolism by activating the lipid synthesis pathways in cells.

HPLC-MS/MS determination of flavonoids in Gleditsiae Spina for its quality assessment.

Gleditsiae Spina, the thorn of Gleditsia sinensis Lam., has been used as an anti-inflammatory, anti-tumor, and anti-bacterial traditional medicine for hundreds of years in China. This study used high-performance liquid chromatography and tandem mass spectrometry combined with chemometric methods to allow the fast and accurate identification and quantification of the flavonoids compounds in Gleditsiae Spina, and created reliable criteria for accurate identification of Gleditsiae Spina and its adulterants. This research provides good evidence for the classification and quality evaluation of Gleditsiae Spina. Firstly, eight flavonoids compounds were detected and identified on the basis of their mass spectra, fragment characteristics, and comparison with published data. Then the mass spectroscopic fragmentation pathways of these compounds were determined and, in addition rutin, isoquercitrin, and quercitrin were detected in Gleditsiae Spina for the first time. The quantification was performed on a triple quadrupole tandem mass spectrometer in multi-reaction monitoring mode, and the baseline separation of the eight bioactive flavonoids components was achieved within 13 min. Furthermore, the proposed method was successfully applied for simultaneous quantitative determination of the eight Gleditsiae Spina compounds and adulterants obtained from different sources in China. Then, we built a classification model which showed a high level of accuracy predicting 100% of the samples, correctly.

Metabonomic Study of Biochemical Changes in Human Hair of Heroin Abusers by Liquid Chromatography Coupled with Ion Trap-Time of Flight Mass Spectrometry.

Hair analysis is with the advantage of non-invasive collection and long surveillance window. The present study employed a sensitive and reliable liquid chromatography coupled with ion trap-time of flight mass spectrometry method to study the metabonomic characters in the hair of 58 heroin abusers and 72 non-heroin abusers. Results indicated that certain endogenous metabolites, such as sorbitol and cortisol, were accelerated, and the level of arachidonic acid, glutathione, linoleic acid, and myristic acid was decreased in hair of heroin abusers. The metabonomic study is helpful for further understanding of heroin addiction and clinical diagnosis.

New phenanthrene derivatives with nitric oxide inhibitory and radical-scavenging activities from Pholidota imbricata Hook.

One new phenanthrene derivative phoimbrtol A (1) with seven known compounds, loddigesiinol B (2), shanciol B (3), (-)-medioresinol (4), (-)-pinoresinol (5), quercetin 3-O-ß-L-arabinofuranoside (6), luteolin 7-O-ß-glucoside (7) and platycaryanin D (8) have been isolated from the ethyl acetate extract of the air-dried whole plant of Pholidota imbricata Hook. Their inhibitory effects on nitric oxide (NO) production and 1,1-diphenyl-2-picrylhydrazil (DPPH) radical scavenging activity were examined. Among these compounds, 8 exhibited the most potent activity at NO production inhibitory assay and DPPH radical scavenging assay, stronger than those of the familiar antioxidative agents, quercetin and resveratrol.

Metabonomics study of the protective effects of green tea polyphenols on aging rats induced by d-galactose.

This article was designed to study metabonomic characters of aging induced by d-galactose (d-gal) and the protective effects of green tea polyphenols (GTP). Plasma samples from control, d-gal and GTP treated rats were analysed by ultra-performance liquid chromatography coupled with mass spectrometry (UPLC/MS) in positive mode. Coupled with biochemistry and histopathology results, the significant difference in metabolic profiling between d-gal treated group and the GTP treated group by using the principal components analysis (PCA) indicated that changes in global plasma metabolites were occurred. Some significantly changed metabolites like lysophosphatidylcholines, tryptophan, dihydrosphingosine and phytosphingosine have been found and identified. These changes in plasma metabolites are related to the perturbations of lecithin metabolism, amino acid metabolism and phospholipids metabolism, which may be helpful to further understand the action mechanisms of GTP.