Antihyperlipidemic effect of tyrosol, a phenolic compound in streptozotocin-induced diabetic rats

We investigated the antihyperlipidemic effects of tyrosol in streptozotocin (STZ)-induced diabetic rats. Rats were injected intraperitoneally with STZ (40 mg/kg), and these established experimental rats were treated with tyrosol (20 mg/kg) and glibenclamide (600 µg/kg) for 45 days. The observed results revealed that tyrosol treatment significantly reduced plasma glucose, plasma, and liver total cholesterol, triglycerides, free fatty acids, phospholipids, plasma low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, atherogenic index, and significantly increased plasma insulin and high-density lipoprotein cholesterol in STZ-induced diabetic rats. The activity of 3-hydroxy 3-methylglutaryl coenzyme A reductase significantly reduced in the liver, whereas the activities of lipoprotein lipase and lecithin cholesterol acyltransferase were significantly increased in the plasma of tyrosol treated STZ-induced diabetic rats. Histological examination showed that tyrosol treatment remarkably reduced lipid accumulation in the liver of STZ-induced diabetic rats. The present study revealed that tyrosol exhibits potent antihyperlipidemic effects in STZ-induced diabetic rats.

Charge compensation assisted enhancement of photoluminescence in combustion derived Li+ co-doped cubic ZrO2:Eu3+ nanophosphors

Red light emitting cubic Zr_0.99Eu_0.01O₂:Li⁺ (0-9 mol%) nanoparticles are synthesized by a low temperature, self-propagating solution combustion method using oxalyl di-hydrazide (ODH) as fuel. In this study, we report systematic investigation of the effect of lithium ion (Li⁺) concentration on the structural properties and the photoluminescence of zirconia. With increasing lithium concentration, the crystallinity of the samples increases and the lattice strain decreases. The higher crystallinity is likely due to charge compensation achieved by replacing one Zr⁴⁺ ion by a Eu³⁺ and a Li⁺ ion. Scanning electron micrographs (SEM) reveal a mesoporous structure characteristic of combustion derived nanomaterials. Photoluminescence (PL) spectra show that the intensity of the red emission (606 nm) is highly dependent on Li⁺ ion concentration. Furthermore there is a promising enhancement in the associated lifetime. Upon Li⁺ doping, the PL intensity of the samples is found to increase by two fold compared to the undoped sample. Variation of PL intensity with Li⁺ concentration is attributed to the differences in probability of non-radiative recombination (relaxing). Intensity parameters (Ω₂, Ω) and radiative properties such as transition rates (A), branching ratios (β), stimulated emission cross-section (σ_e), gain bandwidth (σ_e × Δλ_eff) and optical gain (σ_e × τ) are calculated using the Judd-Ofelt theory. The calculated values suggest that in optimally co-doped samples, in addition to improved crystallinity and charge compensation, the lowering of Eu³⁺ site symmetry and the increase in the covalency of Eu-O bonding due to interstitial Li are responsible for the observed enhancement in PL intensity.

Beneficial effects of tyrosol on altered glycoprotein components in streptozotocin-induced diabetic rats

CONTEXT

Olive oil is the major source of tyrosol which is a natural phenolic antioxidant. Olive oil constitutes a major component of the Mediterranean diet that is linked to a reduced incidence of chronic diseases.

OBJECTIVE

This study evaluates the effects of tyrosol on altered glycoprotein components in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

Diabetes mellitus was induced in male Wistar rats by streptozotocin (40 mg/kg body weight). These rats were administered tyrosol (20 mg/kg body weight) and glibenclamide (600 μg/kg body weight) orally daily for 45 days. Plasma glucose, plasma insulin, glycoprotein components such as hexose, hexosamine, sialic acid and fucose in the plasma, liver and kidney, and histopathogy of tissues were analyzed.

RESULTS

Diabetic rats revealed significant (p < 0.05) increase in the levels of glucose, hexose, hexosamine, sialic acid and fucose (277.17, 152.45, 100.43, 79.69 and 49.29 mg/dL) in the plasma; decrease in the levels of palsma insulin (6.12 μU/mL) and sialic acid (4.36 and 5.03 mg/g) in the liver and kidney; significant (p < 0.05) increase in hexose (49.33 and 46.82 mg/g), hexosamine (22.68 and 33.20 mg/g) and fucose (31.63 and 32.44 mg/g) in the liver and kidney. Further, periodic acid-Schiff staining of tissues revealed positive-stain accumulation in diabetic rats. Tyrosol treatment showed significant (p < 0.05) effects on all the biochemical parameters and histopathology studied in streptozotocin- nduced diabetic rats. Also, the in vitro study revealed the antioxidant effect of tyrosol.

DISCUSSION AND CONCLUSIONS

Thus, tyrosol protects streptozotocin-induced diabetic rats from the altered glycoprotein components. Further, this study can be extrapolated to humans.

Modulatory effects of naringin on hepatic key enzymes of carbohydrate metabolism in high-fat diet/low-dose streptozotocin-induced diabetes in rats

We evaluated the modulatory effects of naringin on altered hepatic key enzymes of carbohydrate metabolism in high-fat diet/low-dose streptozotocin-induced diabetic rats. Oral treatment of naringin at a doses of 20, 40 and 80 mg/kg body weight to diabetic rats for 30 days resulted in a significant reduction in the levels of plasma glucose, blood glycosylated hemoglobin and increase in the levels of plasma insulin and blood hemoglobin. The altered activities of the hepatic key enzymes of carbohydrate metabolism such as hexokinase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, glucose-6-phosphate dehydrogenase, glycogen synthase, glycogen phosphorylase and glycogen content of diabetic rats were significantly reverted to near normal levels by the treatment of naringin in a dose-dependent manner. Naringin at a dose of 80 mg/kg body weight showed the highest significant effect than the other two doses (20 and 40 mg/kg). Further, immunohistochemical observation of pancreas revealed that naringin-treated diabetic rats showed the increased number of insulin immunoreactive β-cells, which confirmed the biochemical findings. These findings revealed that naringin has potential antihyperglycemic activity in high-fat diet/low-dose streptozotocin-induced diabetic rats.

A phase II study of axitinib (AG-013736) in patients with incurable adenoid cystic carcinoma

BACKGROUND

Recurrent/metastatic adenoid cystic carcinoma (ACC) is an incurable disease with no standard treatments. The majority of ACCs express the oncogenic transcription factor MYB (also c-myb), often in the context of a MYB gene rearrangement. This phase II trial of the tyrosine kinase inhibitor (TKI) axitinib (Pfizer) tested the hypothesis that targeting pathways activated by MYB can be therapeutically effective for ACC.

PATIENTS AND METHODS

This is a minimax two-stage, phase II trial that enrolled patients with incurable ACC of any primary site. Progressive or symptomatic disease was required. Patients were treated with axitinib 5 mg oral twice daily; dose escalation was allowed. The primary end point was best overall response (BOR). An exploratory analysis correlating biomarkers to drug benefit was conducted, including next-generation sequencing (NGS) in 11 patients.

RESULTS

Thirty-three patients were registered and evaluable for response. Fifteen patients had the axitinib dose increased. Tumor shrinkage was achieved in 22 (66.7%); 3 (9.1%) had confirmed partial responses. Twenty-five (75.8%) patients had stable disease, 10 of whom had disease stability for >6 months. The median progression-free survival (PFS) was 5.7 months (range 0.92-21.8 months). Grade 3 axitinib-related toxicities included hypertension, oral pain and fatigue. A trend toward superior PFS was noted with the MYB/NFIB rearrangement, although this was not statistically significant. NGS revealed three tumors with 4q12 amplification, producing increased copies of axitinib-targeted genes PDGFR/KDR/KIT. Two 4q12 amplified patients achieved stable disease for >6 months, including one with significant tumor reduction and the longest PFS on study (21.8 months).

CONCLUSIONS

Although the primary end point was not met, axitinib exhibited clinical activity with tumor shrinkage achieved in the majority of patients with progressive disease before trial enrollment. Analysis of MYB biomarkers and genomic profiling suggests the hypothesis that 4q12 amplified ACCs are a disease subset that benefit from TKI therapy.

Improved Memory Effect of ZnO Nanorods Embedded in an Insulating Polymethylmethacrylate Layer

Fabrication and characterization of memory devices using ZnO nanorod layer grown by chemical-bath method is reported. The fabricated memory device was found exhibit electrical bistability and nonvolatile memory phenomenon. An additional Polymethylmethacrylate (PMMA) polymer layer coated on ITO substrate prior to nanorod deposition has been found improve the LRS/HRS ratio of the device. The current-voltage characteristics of the memory devices are discussed in terms of formation and rupture of conductive filaments. The devices have shown consistent electrical bistable behavior even for 10(5) resistance-switching cycles. This hybrid ITO/PMMA-ZnO NRs/Al device has potential applications in the field of bistable random access memories.

Tyrosol, a phenolic compound, ameliorates hyperglycemia by regulating key enzymes of carbohydrate metabolism in streptozotocin induced diabetic rats

The present study was designed to evaluate the effects of tyrosol, a phenolic compound, on the activities of key enzymes of carbohydrate metabolism in the control and streptozotocin-induced diabetic rats. Diabetes mellitus was induced in rats by a single intraperitoneal injection of streptozotocin (40 mg/kg body weight). Experimental rats were administered tyrosol 1 ml intra gastrically at the doses of 5, 10 and 20mg/kg body weight and glibenclamide 1 ml at a dose of 600 μg/kg body weight once a day for 45 days. At the end of the experimental period, diabetic control rats exhibited significant (p<0.05) increase in plasma glucose, glycosylated hemoglobin with significant (p<0.05) decrease in plasma insulin, total hemoglobin and body weight. The activities of key enzymes of carbohydrate metabolism such as phosphoenolpyruvate carboxykinase, fructose-1,6-bisphosphatase and glucose-6-phosphatase were significantly (p<0.05) increased and the activities of hexokinase and glucose-6-phosphate dehydrogenase were significantly (p<0.05) decreased in the liver and kidney of diabetic control rats. Further, antioxidants were lowered in diabetic control rats. A significant (p<0.05) decline in glycogen level in the liver and muscle and glycogen synthase activity in the liver and a significant (p<0.05) increase in the activity of liver glycogen phosphorylase were observed in diabetic control rats compared to normal control rats. Oral administration of tyrosol to diabetic rats reversed all the above mentioned biochemical parameters to near normal in a dose dependent manner. Tyrosol at a dose of 20mg/kg body weight showed the highest significant effect than the other two doses. Immunohistochemical staining of pancreas revealed that tyrosol treated diabetic rats showed increased insulin immunoreactive β-cells, which confirmed the biochemical findings. The observed results were compared with glibenclamide, a standard oral hypoglycemic drug. The results of the present study suggest that tyrosol decreases hyperglycemia, by its antioxidant effect.

Role of solution pH on the microstructural properties of spin coated cobalt oxide thin films

Cobalt Oxide (Co3o4) thin films have been successfully coated onto glass substrates at various solution pH by sol-gel spin coating technique. The film thickness was estimated using weight gain method and it revealed that the film thickness increased with solution pH values. The prepared film structural, morphological, optical and electrical properties were studied using X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis-NIR spectrophotometer and Vander Pau method, respectively. The structure of the films were found to be face centered cubic with preferential orientation along (311) plane. X-ray line profile analysis was used to evaluate the micro structural parameters such as crystallite size, micro strain, dislocation density and stacking fault probability. The crystallite size values are increased with increase of solution pH values and maximum value of crystallite is estimated at 40.8 nm at solution pH 8 +/- 0.1. Morphological results showed that the pH of the solution has a marked effect on morphology of the Co3O4 thin films. The optical studies revealed that the band gap can be tailored between 2.16 to 2.31 eV by altering pH. The thin film formed at a solution pH 7 is found to have a low resistivity and high mobility. The electrical resistivity (p), carrier concentration (n) and mobility (micro) values are 0.1 x 10(3) omega x cm, 8.9 cm2 gammas(-1) and 6.6 x 10(14) cm(-3), respectively for Co3O4 thin film prepared at solution pH 7 +/- 0.1. EDAX studies showed that the cobalt content increased and the oxygen content decreased with increase of pH.

Low temperature synthesis of pure cubic ZrO2 nanopowder: structural and luminescence studies

Pure cubic zirconia (ZrO2) nanopowder is prepared for the first time by simple low temperature solution combustion method without calcination. The product is characterized by Powder X-ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infra Red spectroscopy (FTIR) and Ultraviolet-Visible spectroscopy (UV-Vis). The PXRD showed the formation of pure stable cubic ZrO2 nanopowders with average crystallite size ranging from 6 to 12 nm. The lattice parameters were calculated from Rietveld refinement method. SEM micrograph shows fluffy, mesoporous, agglomerated particles with large number of voids. TEM micrograph shows honey comb like arrangement of particles with particle size ∼10 nm. The PL emission spectrum excited at 210 nm and 240 nm consists of intense bands centered at ∼365 and ∼390 nm. Both the samples show shoulder peak at ∼420 nm, along with four weak emission bands at ∼484, ∼528, ∼614 and ∼726 nm. TL studies were carried out pre-irradiating samples with γ-rays ranging from 1 to 5 KGy at room temperature. A well resolved glow peak at 377 °C is recorded which can be ascribed to deep traps. With increase in γ radiation there is linear increase in TL intensity which shows the possible use of ZrO2 as dosimetric material.

High-performance memory device using graphene oxide flakes sandwiched polymethylmethacrylate layers

Organic bistable devices (OBDs) using graphene oxide (GO) flakes sandwiched polymethylmethacrylate (PMMA) films were fabricated. These devices exhibited two accessible conducting states, that is, a low-conductivity (OFF) state and a high-conductivity (ON) state. The devices can be switched to ON state under a negative electrical sweep; it can also be reset to the initial OFF state by a reverse (positive) electrical sweep. Detailed I-V measurements have shown that in ITO/PMMA/GO/PMMA/Al sandwiches the resistive switching originates from the formation and rupture of conducting filaments. The ON/OFF ratio of the OBDs was approximately 5 x 10(3), reproducibility of more than 10(5) cycles, and retention time of 10(4) s. These properties show that the device is promising for high-density, low-cost memory application.

Variation of microstructural and optical properties in SILAR grown ZnO thin films by thermal treatment

The influence of thermal treatment on the structural and morphological properties of the ZnO films deposited by double dip Successive ionic layer by adsorption reaction is presented. The effect of annealing temperature and time in air ambient is presented in detail. The deposited films were annealed from 200 to 400 degrees C in air and the structural properties were determined as a function of annealing temperature by XRD. The studies revealed that films were exhibiting preferential orientation along (002) plane. The other structural parameters like the crystallite size (D), micro strain (epsilon), dislocation density (delta) and stacking fault (alpha) of as-deposited and annealed ZnO films were evaluated and reported. The optical properties were also studied and the band gap of the ZnO thins films varied from 3.27 to 3.04 eV with the annealing temperature. SEM studies revealed that the hexagonal shaped grains with uniformly distributed morphology in annealed ZnO thin films. It has been envisaged using EDX analysis that the near stoichiometric composition of the film can be attained by thermal treatment during which microstructural changes do occur.

Type 2 lepra reaction as a cause of pyrexia of unknown origin

Leprosy, a commonly encountered disease, can rarely present as a reactional state de novo with fever as the main presenting feature. Here we describe an uncommon presentation of leprosy [with type 2 lepra reaction] as pyrexia of unknown origin with prominent rheumatologic manifestations [acute polyarthritis], renal involvement and generalized lymphadenopathy with rare presentation of type 2 lepra reaction without the classic skin lesions of erythema nodosum leprosum, occurring in a treatment naive patient without prior history of leprosy.

Morphological properties of Ag₂SeTe nano thin films prepared by thermal evaporation

Semiconducting silver selenide telluride (Ag₂SeTe) thin films were prepared with different thicknesses onto glass substrates at room temperature using thermal evaporation technique. The structural properties were determined as a function of thickness by X-ray diffraction exhibiting no preferential orientation along any plane; however, the films are found to have peaks corresponding to mixed phase. The morphology of these films was studied using scanning electron microscope and atomic force microscopy respectively, and is reported. The morphological properties are found to be very sensitive to the thin film thickness. The composition of the films is also estimated using energy dispersive analysis using X-rays and are also reported.

Morphology selection for cupric oxide thin films by electrodeposition

Polycrystalline cupric oxide thin films were deposited using alkaline solution bath employing cathodic electrodeposition method. The thin films were electrodeposited at various solution pH. The surface morphology and elemental analyzes of the films were studied using scanning electron microscopy (SEM) and energy dispersive X-ray analysis, respectively. SEM studies revealed that the surface morphology could be tailored suitably by adjusting the pH value during deposition. Mesh average on multiple lattice mode atomic force microscopy image was obtained and reported.

Studies on the biosorption of hexavalent chromium from aqueous solutions by using boiled mucilaginous seeds of Ocimum americanum

Investigations were carried out to study the chromium removal efficiency of boiled mucilaginous seeds of Ocimum americanum. Batch experiments were conducted to study the biosorption kinetics of chromium removal for the concentrations 10mg/L, 20mg/L and 40 mg/L of chromium(VI) solutions. The biosorbent dosage was 8 g dry seeds/L. The toxic hexavalent chromium was reduced to less toxic chromium(III) in the presence of seeds and the reduced chromium was adsorbed on the mucilage of seeds. Both the chromium(VI) and chromium(III) were present in the aqueous phase. The optimum chromium reduction and adsorption was observed at the pH value 1.5. The biosorption data fitted well with Langmuir isotherm. The biosorption capacity calculated from the Langmuir isotherm was q=32 mg chromium(III)/g of dry seeds. The continuous column study was also carried out at the flow rate of 27 mL/h for the initial concentration 25mg/L of chromium(VI) feed solution using a packed bed column filled with boiled mucilaginous seeds. The maximum reduction of chromium(VI) to chromium(III) in the packed bed was 80%. The percentage removal of reduced chromium from the aqueous solution was 56.25%. This value was maintained constant until 0.52 L of chromium(VI) solution was pumped through the packed bed column. Thus the naturally immobilized polysaccharides on the seeds mimic the microbial polysaccharides in terms of their ability to adsorb heavy metals with an added advantage of making the immobilization step unnecessary which is a major cost factor of the metal removal process when microbial exopolysaccharides used. The uniform size and spherical shape of swollen seeds give an additional advantage to use them in a packed bed column for continuous removal of chromium(VI) from aqueous solutions.

Eu(3+) doped gadolinium oxysulfide (Gd(2)O(2)S) nanostructures-synthesis and optical and electronic properties

One-dimensional Eu(3+) doped gadolinium oxysulfide (Gd(2)O(2)S:Eu(3+)) nanotubes/nanorods have been synthesized via precursors of Gd(OH)(3) nanostructures using a hydrothermal technique. The blue-shifts in the optical spectra for the Gd(2)O(2)S:Eu(3+) system corresponding to the fundamental absorption and Eu(3+)-X(2-) ligand (X =  O/S) charge transfer bands (CTBs) are significant (∼0.22-0.36 eV) with respect to the bulk counterpart. The nanotubes are good candidates for investigating the size-induced electrical and optical properties of functional oxysulfides. In order to identify the origin and nature of the electronic transitions observed in the visible region, optical and photo-induced impedance measurements have been extended to the nanotubes in this report.