Highly Specific Antibiotic Detection on Water-Stable Black Phosphorus Field-Effect Transistors.

Two-dimensional (2D) black phosphorus (BP) has been reported to have appealing semiconducting properties as the sensing channel in field-effect transistor (FET) sensors. However, the intrinsic instability of BP in water greatly hinders its application, and little is known about its sensing performance and mechanism in aqueous medium. Herein, a water-stable BP FET sensor for antibiotic detection is reported. A novel surface engineering strategy with Ag+ coordination and melamine cyanurate (MC) supramolecular passivation is utilized to enhance the stability and transistor performance of BP. With molecularly imprinted polymers (MIPs) as the detection probe for tetracycline, the BPAg(+)/MC/MIPs sensor shows high sensitivity to tetracycline with a detection limit of 7.94 nM and a quick response within 6 s as well as high selectivity against other antibiotics with similar molecular structures. A new sensing mechanism relying on the conjugation effect of the probe structure is proposed, and new knowledge about alkalinity-enhanced and ionic strength-related response from the electrostatic gating effect is given based on the solution chemistry impact study. This work offers an efficient surface engineering strategy to enable the application of 2D BP for antibiotic detection in aqueous medium and presents a new sensing mechanism in chemical analysis by FET sensors.

Protective effect of 2-dodecyl-6-methoxycyclohexa-2, 5-diene-1, 4-dione, isolated from Averrhoa carambola L., against Aß1-42-induced apoptosis in SH-SY5Y cells by reversing Bcl-2/Bax ratio.

BACKGROUND AND PURPOSE: Aß1-42-induced neurotoxicity has been considered as a possible mechanism to aggravate the onset and progression of Alzheimer's disease (AD). In this study, we aim to determine the protective effect of DMDD on the apoptosis of SH-SY5Y cells induced by Aß1-42 and elucidate potential mechanism of DMDD's protective function in apoptosis. EXPERIMENTAL APPROACH: CCK-8, AnnexinV-FITC/PI flow cytometry, and transmission electron microscopy analysis were used to determine the protection of DMDD on Aß1-42-evoked apoptosis of SH-SY5Y cells. Cytochrome c release, JC-1 staining, and measuring the protein of Bcl-2 family by Western blot were applied to elucidate the mechanism of DMDD's protective function in apoptosis. KEY RESULTS: Three concentration of DMDD (5 µmol/L, 10 µmol/L, and 20 µmol/L) rescues the cell viability loss and apoptosis of SH-SY5Y cells cultivated in Aß1-42. The expressions of cleaved Caspase-3, -8, -9, the cytochrome c release, and mitochondrial membrane potential loss were inhibited by DMDD in Aß1-42-insulted SH-SY5Y cells. The Western blot analysis showed that DMDD pretreatment clearly downregulated the protein of Bax and upregulated Bcl-2. Moreover, the Bcl-2/Bax ratio was obviously decreased in cells only exposed to Aß1-42, but, which was suppressed by treated with DMDD. CONCLUSION AND IMPLICATIONS: DMDD attenuated the apoptosis of SH-SY5Y cells induced by Aß1-42 through reversing the Bcl-2/Bax ratio.

Protective Effect of Benzoquinone Isolated from the Roots of Averrhoa carambola L. on Streptozotocin-Induced Diabetic Mice by Inhibiting the TLR4/NF-κB Signaling Pathway.

BACKGROUND: Studies have demonstrated that the roots of Averrhoa carambola L. (Oxalidaceae), a traditional Chinese medicine, can be used to treat diabetes and diabetes-related diseases. Nevertheless, the potential beneficial effects and mechanism of benzoquinone isolated from the roots of Averrhoa carambola L. (BACR) on diabetes remain unclear. METHODS: Diabetic Kunming mice were injected with STZ (120 mgkg-1) in the tail vein. Fasting blood glucose (FBG) and the change of body weight were measured after oral administration of BACR (120, 60, 30 mg/kg/d) every week. The levels of the total cholesterol (TC), triglyceride (TG), free fatty acids (FFA), glucosylated hemoglobin (GHb), fasting insulin (FINS), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured. The histological examination of pancreatic tissues and the TLR4/NF-κB pathway was analyzed by RT-PCR, immunohistochemistry and Western blot. RESULTS: The study found that clearly the BACR obviously reduced the blood glucose, serum lipids, GHb and FINS. In addition, BACR treatment markedly reduced the release of inflammatory factors, including IL-6 and TNF-α, and down-regulated the expression of the TLR4/NF-κB pathway. CONCLUSION: BACR has potential benefits for the treatment of diabetes by ameliorating metabolic functions and attenuating the inflammatory response via inhibition of the activation of theTLR4/NF-κB pathway.

The Emulsifying Properties of Hydrogenated Rosin Xylitol Ester as a Biomass Surfactant for Food: Effect of pH and Salts.

The xylitol ester of hydrogenated rosin (XEHR) was obtained for the first time from biomass-based hydrogenated rosin and xylitol using an environmentally friendly, high-pressure CO2 catalytic synthesis. This compound is intended for use as an emulsifier for food. Analyses by ICP-AES showed the absence of heavy metal residues in the product, such that it met food standards. Fourier transform infrared and nuclear magnetic resonance spectroscopies together with gel permeation chromatography confirmed the successful esterification and the formation of a monoester and diester with molar masses of 427 and 772 g/mol. The emulsification of water/soybean oil mixtures by adding the XEHR was assessed at pH values of 4, 6.86, and 10 and in the presence of NaCl, KCl, MgCl2, and CaCl2. The XEHR was found to act as an emulsifier by reducing the interfacial tension of such mixtures to less than 2 mN/m under all conditions. The highest emulsifying activity index (9.52 m2/g) and emulsifying stability index (94.53%) were obtained after adding MgCl2 (100 mM). Particle size and confocal microscopy showed that the presence of salts gave a more uniform droplet size and a finer emulsion structure. The high viscosities of the emulsions containing salts also suggested a more cohesive oil droplet network.

2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione isolated from Averrhoa carambola L. root ameliorates diabetic nephropathy by inhibiting the TLR4/MyD88/NF-κB pathway.

BACKGROUND: Averrhoa carambola L. is a traditional medicinal herb that has long been used to treat diabetes. Our previous studies found that 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) isolated from A. carambola L. roots could ameliorate diabetic nephropathy (DN), but its exact mechanism remains unclear. METHODS: A DN model was established by streptozotocin (STZ, 100 mg/kg body weight) in TLR4 knockout (TLR4-/-, KO) mice and wild-type (WT) mice. Body weight and blood glucose were evaluated after oral administration of DMDD (12.5, 25, 50 mg/kg body weight/d) in diabetic mice. The levels of serum lipids, including TC, TG, HDL, and LDL and kidney function indexes Scr and BUN, were detected by biochemical equipment. The levels of inflammatory cytokines including IL-6 and TNF-α, were determined by ELISA kits. Furthermore, changes in renal ultrastructure were observed by electron microscopy. Western blot analysis and RT-PCR were used to assess the protein expression and mRNA levels of TLR4, MyD88 and NF-κB. RESULTS: DMDD treatment attenuated diabetic nephropathy, as a result of a decline in blood glucose, serum creatinine, and blood urine nitrogen levels and an increase in the quantity and density of podocytes, combined with improved dyslipidaemia. DMDD treatment inhibited the inflammatory response and downregulated the expression of the TLR4/MyD88/NF-κB pathway in diabetic mice, and these changes were significantly different in TLR4-/- mice. CONCLUSION: DMDD alleviates diabetic nephropathy by mitigating kidney damage and inflammation via the inhibition of the TLR4/MyD88/NF-κB signalling pathway.

Protective Effects of 2-Dodecyl-6-Methoxycyclohexa-2,5 -Diene-1,4-Dione Isolated from Averrhoa Carambola L. (Oxalidaceae) Roots on Neuron Apoptosis and Memory Deficits in Alzheimer's Disease.

BACKGROUND/AIMS: The roots of Averrhoa carambola L. (Oxalidaceae) have long been used as a traditional Chinese medicine for the treatment of headaches, vomiting, coughing and hangovers. 2-dodecyl-6-methoxycyclohexa-2, 5-1, 4-dione (DMDD) has been isolated from A. carambola L. roots, and this study was carried out to investigate the potential beneficial effects of DMDD on neuron apoptosis and memory deficits in Alzheimer's disease. METHODS: The effects of a DMDD on learning and memory in APP/PS1 transgenic AD mice in vivo were investigated via Morris water maze and Y-type electric maze tests. In vitro, Cell viability was assessed by CCK-8. Apoptosis was assessed by Annexin V-FITC/PI flow cytometry assay, and transmission electron microscopy assay. Relative quantitative real-time PCR and Western blot were used to determine the expressions of genes and proteins. RESULTS: The spatial learning and memory deficit, fear memory deficit, as well as apoptosis and loss of neuron in hippocampal area of APP/PS1 mice were reversed by DMDD in APP/PS1 transgenic AD mice. DMDD protected against the Aß1-42-induced apoptosis, loss of mitochondria membrane potential, induction of pro-apoptotic Bcl-2 family protein Bax, reduction of anti-apoptotic Bcl-2 family proteins Bcl-2, and activation of Caspase-3, and -9 in PC-12 cells. The Bcl-2/Bax ratio was also increased in DMDD-pretreated PC-12 cells in vitro and APP/PS1 mice in vivo. CONCLUSION: DMDD has potential benefit on treating learning and memory deficit in APP/PS1 transgenic AD mice, and its effects may be associated with reversing the apoptosis of neuron via inhibiting Bax/Bcl-2 mediated mitochondrial membrane potential loss.

Hepatoprotective effects of Yulangsan flavone against carbon tetrachloride (CCl4)-induced hepatic fibrosis in rats.

BACKGROUND: Yulangsan flavone (YLSF) was extracted from the root of Millettia pulchra Kurz var-laxior (Dunn) Z. Wei, which has been widely used for liver disease treatment in the Guangxi province of China. HYPOTHESIS/PURPOSE: The study was conducted to demonstrate the hepatoprotective effects of YLSF against CCl4-induced hepatic fibrosis in rats, meanwhile revealing the potential mechanism. STUDY DESIGN: Sprague-Dawley (SD) rats of both sexes were randomly divided into two groups: hepatic fibrosis group and normal control (NC) group. The rats in the hepatic fibrosis group were given 1 ml/kg 50% CCl4 (1:1 mixed with peanut oil), while those in the NC group were given 1 ml/kg normal saline (NS), both via intragastric administration. The established experimental rat model from the hepatic fibrosis group was confirmed by pathological inspection and randomly divided into five groups: three YLSF groups (20 mg/kg, 40 mg/kg and 80 mg/kg), a colchicine group (0.20 mg/kg) and a model group (10 ml/kg NS). All rats were treated with corresponding drugs or NS once a day for four consecutive weeks. Twenty-four hours after the last administration, blood serum and hepatic tissue were collected. METHODS: The activities of ALT and AST in the serum and the levels of SOD, MDA, GSH and GSH-Px in hepatic tissue were analysed, the indexes of liver, spleen and thymus were counted, the degree of hepatic injury was examined using HE and Masson staining, and the mRNA expression of Col-1, TIMP-1 and TGF-ß1 in hepatic tissues was detected. RESULTS: Compared with the model group, experimental results showed that YLSF and colchicine could reduce the levels of AST, ALT and MDA, increase the levels of SOD, GSH and GSH-Px, enhance rat survivability, decrease the liver, spleen and thymus index, significantly lessen collagen deposition and tissue damage and down-regulate the mRNA expression of Col-1, TIMP-1 and TGF-ß1. CONCLUSIONS: Our findings confirm that YLSF has a certain curative effect on rats with liver fibrosis induced by CCl4, and its mechanism may include attenuating free radicals, inhibiting lipid peroxidation and accelerating extracellular matrix degradation by down-regulating expression of related genes.

Protective Effects of 2-Dodecyl-6-Methoxycyclohexa-2,5 -Diene-1,4-Dione Isolated from Averrhoa Carambola L. (Oxalidaceae) Roots on High-Fat Diet-Induced Obesity and Insulin Resistance in Mice.

BACKGROUND/AIMS: The roots of Averrhoa carambola L. (Oxalidaceae) have long been used as a traditional Chinese medicine for the treatment of diabetes and diabetes-related diseases. 2-dodecyl-6-methoxycycyclohexa-2,5-1,4-dione (DMDD) has been isolated from A. carambola L. roots, and this study was carried out to investigate the potential beneficial effects of DMDD on obesity and insulin resistance induced by a high-fat diet (HFD) in mice. METHODS: C57BL/6J mice were fed a HFD for 16 weeks and orally administered DMDD (12.5, 25, or 50 mg/kg of body weight per day) and metformin (280 mg/kg of body weight per day) for the last 4 weeks. RESULTS: The body weights and adipose tissue weights as well as the serum levels of blood glucose, total cholesterol, triglycerides, free fatty acids, insulin, interleukin-6, and tumor necrosis factor-α were significantly decreased by DMDD, and the expression of Toll-like receptor 4 (TLR4) and myeloid differentiation factor (Myd88) in the epididymal adipose tissue was downregulated by DMDD. In contrast, insulin sensitivity was enhanced. The results of the glucose tolerance tests, insulin tolerance tests, and insulin release tests indicated that there was a marked improvement in insulin secretion, and the areas under the curve corresponding to the three tests were also significantly decreased by DMDD. The activities of superoxide dismutase and glutathione peroxidase were simultaneously enhanced, whereas the content of malondialdehyde was decreased by DMDD in the liver homogenates of the C57BL/6J mice. In addition, hepatic steatosis and adipocyte hypertrophy, as assessed by H&E staining of liver and adipose tissues, were significantly improved by DMDD. CONCLUSION: These data suggest that MDD has potential benefits for the treatment of HFD-induced obesity and insulin resistance, and its effects may be associated with improvements in lipid metabolism and inhibition of the expression of TLR4 in adipose tissues.

Stereospecific antioxidant effects of ginsenoside Rg3 on oxidative stress induced by cyclophosphamide in mice.

Ginsenoside Rg3 is one of the active ingredients isolated from Panax ginseng C.A. Meyer. Previous investigation demonstrated that Rg3 was stereospecific in promotion of the immune response. The present study was designed to evaluate Rg3 and its epimers, 20(R)-Rg3 and 20(S)-Rg3, for their effects on oxidative stress induced by cyclophosphamide (Cy) in mice. Forty-eight mice were randomly distributed into 6 groups and intraperitoneally administered saline solution, Cy, 20(R)-Rg3, 20(S)-Rg3, 20(R)-Rg3+Cy or 20(S)-Rg3+Cy. After that, the spleen, thymus and serum were collected to measure the indices of the organs and oxidative parameters. The results showed that Rg3 significantly inhibited Cy-induced oxidative stress in mice by increasing the indices of the spleen and thymus and total antioxidant capacity, elevating the activities of catalase, superoxidase dismutase and lysozyme as well as decreasing the activity of xanthine oxidase and the levels of malondialdehyde and nitric oxide. Rg3 was stereospecific in antioxidant activities as R form exhibited significantly higher antioxidant effects than S form. Therefore, R form should be used when Rg3 is considered to be used as an antioxidant agent.