Bilberry Anthocyanins (Vaccinium myrtillus L.) Induced Apoptosis of B16-F10 Cells and Diminished the Effect of Dacarbazine.

Anthocyanins have been reported to have potential as dietary or pharmaceutical supplements in the application of cancer prevention and adjunctive treatment. However, there are few studies on the effect of anthocyanins on melanoma, which have only been performed in cell lines. The objective of this work was to investigate the anticancer effects and mechanisms of bilberry anthocyanin extract (BAE) on melanoma In Vitro and In Vivo. Moreover, a primary study was done to investigate how BAE influenced C57BL/6 mice bearing subcutaneous B16-F10 tumors treated with dacarbazine (DTIC). BAE-induced apoptosis in B16-F10 cells was associated with activation of the mitochondrial pathway induced by increased reactive oxygen species. More, In Vivo anticancer activity studies indicated that BAE attenuated melanoma growth, as identified by hematoxylin-eosin staining, Ki-67, and TUNEL assays. Further western blot results revealed higher phospho-Akt expression with the combination of BAE and DTIC, indicating no suppression of the PI3K/AKT signaling pathway. In summary, this study demonstrated the anti-melanoma activity of BAE and investigated its mechanism. Notably, it should be careful to use products enriching BAE for those melanoma patients treated with DTIC.

[Preparation of molecularly imprinted polymers based on covalent organic frameworks and their application to selective recognition of trace norfloxacin in milk].

Norfloxacin (NFX) is an antibiotic that is widely used in animal husbandry. However, the presence of NFX even in trace amounts in animal-derived food may harm human health. Therefore, it is of practical significance to establish a method for monitoring NFX residues in food. Molecularly imprinted polymers (MIPs) imitate interactions established by natural receptors to selectively retain a target molecule, like antibodies or antigens do. MIPs have been widely employed in the selective recognition of specific target molecules from complex samples. Covalent organic frameworks (COFs) are a new type of organic polymer with uniform and ordered crystal structures. COFs form crystal structures by constructing organic units for ordered assembly through reversible chemical reactions. Their porous structure, regular morphology, and easy modification make COFs promising for use as excellent adsorbent carriers. Owing to these advantages of COFs, researchers have attempted to coat one MIP layer on COFs; however, the preparation methods are time-consuming and laborious, and the conditions are harsh. Hence, this study proposes a simple and rapid method for the preparation of novel MIPs with COFs as the support (DP-COF@MIPs) for the selective recognition of NFX. First, a Schiff-base COF (DP-COF) was rapidly synthesized using 3,3'-diaminobenzidine and p-phthalaldehyde with a metal trifluorate as a catalyst at room temperature. Subsequently, a two-step sequence was adopted as the synthesis strategy using NFX as the template, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a crosslinking agent. The entire synthesis was completed within 5 h under mild conditions. The material was then characterized by multiple analytical methods, including field-emission scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and the Brunauer-Emmett-Teller (BET) method (to determine the specific surface area). The experimental results confirmed the successful preparation of DP-COF@MIPs. The DP-COF@MIPs presented a rough and porous surface, with a pore size of approximately 17.79 nm (mesoporous structure). The properties of the material were evaluated by adsorption and regeneration experiments. The kinetic adsorption experiment showed that the DP-COF@MIPs reached adsorption equilibrium in 90 min. Two straight lines were fitted using the pseudo-second-order kinetics model based on the experimental results for thermodynamic adsorption, indicating that the adsorption process was primarily dominated by chemical adsorption. The maximum apparent adsorption capacity was 41.57 mg/g. In the selective and competitive binding test, five drugs, namely ciprofloxacin, dimetridazole, oxytetracycline, sulfadiazine, and chloramphenicol, were selected as the interferents. The experimental results showed that the DP-COF@MIPs possessed good stereoselectivity and competitive recognition ability. The regeneration of DP-COF@MIPs was evaluated by multiple cycles of adsorption-desorption experiments. The loss in the adsorption capacity of the particles was only approximately 4.7% after seven adsorption-desorption cycles. These results from the regeneration experiments show that the DP-COF@MIPs had high stability and reusability in the selective adsorption and separation of NFX. In addition, the employed method could accurately identify trace NFX in milk samples. The average recoveries were in the range of 88.8%-92.9% at three spiked levels (0.03, 0.10, and 0.30 mg/L) with relative standard deviations (RSDs) in the range of 0.6-1.7% (n=3). Notably, the method could successfully determine NFX at contents as low as 0.0020 mg/L in the milk sample with an average recovery of 77.6% and RSD of 6.4% (n=3). This concentration is one-fiftieth of the maximum residue level stipulated by the European Union (EU), and even lower than the limit of detection (LOD) of conventional high performance liquid chromatography (HPLC) methods. The above results confirm that DP-COF@MIPs can be used to determine trace NFX in actual complex samples using HPLC equipment, even when coupled to conventional UV-Vis detectors. This study offers a facile and general method for the preparation of MIPs based on COFs with selective recognition ability.

Antineoplastic Activity Comparison of Bovine Serum Albumin--Conjugated Sulfides Semiconductor Nanomaterials.

Although tumor is one of the most frequently occurring diseases and a leading cause of death, nanotechnology, one of the frontier sciences, is exhibiting its great potential to tumor treatments. The aim of this study was to design a facile and environmentally-friendly method to prepare bovine serum albumin-conjugated heavy metal sulfides nano-materials, including Ag2S, PbS and CdS. Here, bovine serum albumin was introduced in order to direct the synthesis of nano-materials by using its template effect and supply more sites for further modification in future. The crystal structure and morphology were analyzed by XRD and TEM, respectively. Additionally, the antineoplastic activity of nano-materials was compared by cell viability analysis, optical and electron microscopy observation after exposure of the human hepatoma cell line. The results showed that the inhibition effect of heavy metal sulfides on tumor cells was in the order of nano-PbS > bulk CdS > nano-Ag2S > nano-CdS > bulk PbS > bulk Ag2S. It could be concluded that heavy metal sulfides had significantly negative impact on human hepatoma cells growth but it could not be obviously generalized that nano-particles were always more effective to kill tumor cells than bulk materials. The size and surface reactivity might be the important factors causing the difference.

Intensity-dependent effects of repetitive anodal transcranial direct current stimulation on learning and memory in a rat model of Alzheimer's disease.

Single-session anodal transcranial direct current stimulation (tDCS) can improve the learning-memory function of patients with Alzheimer's disease (AD). After-effects of tDCS can be more significant if the stimulation is repeated regularly in a period. Here the behavioral and the histologic effects of the repetitive anodal tDCS on a rat model of AD were investigated. Sprague-Dawley rats were divided into 6 groups, the sham group, the ß-amyloid (Aß) group, the Aß+20µA tDCS group, the Aß+60µA tDCS group, the Aß+100µA tDCS group and the Aß+200µA tDCS group. Bilateral hippocampus of the rats in the Aß group and the Aß+tDCS groups were lesioned by Aß1-40 to produce AD models. One day after drug injection, repetitive anodal tDCS (10 sessions in two weeks, 20min per session) was applied to the frontal cortex of the rats in the tDCS groups, while sham stimulation was applied to the Aß group and the sham group. The spatial learning and memory capability of the rats were tested by Morris water maze. Bielschowsky's silver staining, Nissl's staining, choline acetyltransferase (ChAT) and glial-fibrillary-acidic protein (GFAP) immunohistochemistry of the hippocampus were conducted for histologic analysis. Results show in the Morris water maze task, rats in the Aß+100µA and the Aß+200µA tDCS groups had shorter escape latency and larger number of crossings on the platform. Significant histologic differences were observed in the Aß+100µA and the Aß+200µA tDCS groups compared to the Aß group. The behavioral and the histological experiments indicate that the proposed repetitive anodal tDCS treatment can protect spatial learning and memory dysfunction of Aß1-40-lesioned AD rats.

[Design of low-intermediate frequency electrotherapy and pain assessment system].

Aiming at the single treatment and the design separation between treatment and assessment in electrotherapy equipment, a kind of system including low-intermediate frequency treatment and efficacy evaluation was developed. With C8051F020 single-chip microcomputer as the core and the circuit design and software programming used, the system realized the random switch of therapeutic parameters, the collection, display and data storage of pressure pain threshold in the assessment. Experiment results showed that the stimulus waveform, current intensity, frequency, duty ratio of the system output were adjustable, accurate and reliable. The obtained pressure pain threshold had a higher accuracy (< 0.3 N) and better stability, guiding the parameter choice in the precise electrical stimulation. It, therefore, provides a reliable technical support for the treatment and curative effect assessment.

Structural basis for angiopoietin-1-mediated signaling initiation.

Angiogenesis is a complex cellular process involving multiple regulatory growth factors and growth factor receptors. Among them, the ligands for the endothelial-specific tunica intima endothelial receptor tyrosine kinase 2 (Tie2) receptor kinase, angiopoietin-1 (Ang1) and Ang2, play essential roles in balancing vessel stability and regression during both developmental and tumor-induced angiogenesis. Despite possessing a high degree of sequence identity, Ang1 and Ang2 have distinct functional roles and cell-signaling characteristics. Here, we present the crystal structures of Ang1 both unbound and in complex with the Tie2 ectodomain. Comparison of the Ang1-containing structures with their Ang2-containing counterparts provide insight into the mechanism of receptor activation and reveal molecular surfaces important for interactions with Tie2 coreceptors and associated signaling proteins. Using structure-based mutagenesis, we identify a loop within the angiopoietin P domain, adjacent to the receptor-binding interface, which confers the specific agonist/antagonist properties of the molecule. We demonstrate using cell-based assays that an Ang2 chimera containing the Ang1 loop sequence behaves functionally similarly to Ang1 as a constitutive Tie2 agonist, able to efficiently dissociate the inhibitory Tie1/Tie2 complex and elicit Tie2 clustering and downstream signaling.

Controllable synthesis and adjustable antineoplastic activity of bovine serum albumin-conjugated PbS/Ag2S core/shell nano-composites.

Series of mono-dispersed bovine serum albumin (BSA)-conjugated PbS/Ag(2)S core/shell nano-composites with different Pb/Ag ratios had been successfully synthesized by an ion-exchange method under the gentle conditions using BSA-conjugated PbS nano-crystals as precursors, which were prepared by a biomimetic method. Fourier transform infrared spectra analysis and transmission electron microscopy (TEM) observation demonstrated that BSA was a key factor to control the morphology and size of final products. Additionally, the real-time TEM observation, X-ray powder diffraction and atomic absorption spectroscopy analysis were applied to monitor the synthesis process. The results indicated that the shell thickness and ratio of Pb to Ag could be controlled by adjusting the ion-exchange time. Both metabolic and morphological methods revealed that the proliferation of rat pheochromocytoma (PC 12) cells could be inhibited by BSA-conjugated PbS/Ag(2)S core/shell nano-composites, and the antineoplastic activity was Pb/Ag ratio-dependent. It might be explained by a Trojan horse-type mechanism. Summarily, the present study would be helpful to find a new core/shell nano-composite with higher and controllable antineoplastic activity due to the synergistic reaction of different metal ions.

Parinaric acid methyl ester polymer films with hill-structured features: fabrication and different sensitivities to normal and tumor cells.

Parinaric acid methyl ester (PnA-Me) polymer films with hill-structured features were fabricated by a solvent volatilization in situ cross-linking method. Moreover, nuclear magnetic resonance, Fourier transform infrared, and oxidation kinetic analyses were successfully applied to monitor the formation process of PnA-Me polymer films. The role of PnA-Me monomer concentrations for growth control of the hill structures on a glass matrix had also been investigated. Also, the results demonstrated that size control of the resulting hill structure ranging from 0.56 ± 0.18 to 19.6 ± 3.5 µm could be realized by varying the concentration of the PnA-Me monomer from 0.0117 to 1.5 mg/mL. Additionally, the effects of polymer films with different surface topographical structures on the behaviors of rat mesenchymal stem cells and human pheochromocytoma cells were measured by morphological and metabolic methods. The results revealed that the cell activity of PnA-Me films was topographical structure- and cell-type-dependent. Furthermore, the selective sensitivity of the PnA-Me films to normal and tumor cells supported the potential value as the coatings for the tissue engineering substitutes.

Anodal transcranial direct current stimulation relieves the unilateral bias of a rat model of Parkinson's disease.

The unilaterally lesioned rat model of Parkinson's disease which fails to orient to the food stimuli presented on the contralateral side of its preferential side of body could be induced by the injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle (MFB). We employed transcranial direct current stimulation (tDCS, current intensity: 80 µA, and 40 µA; anodal electrode area: 3.14 mm(2); stimulation time: 30 minutes) over the M1 area to relieve the ipsilateral bias in the rat model. A corridor test was set to count the ipsilateral bias of the rats. In this experiment, 30 Sprague-Dawley rats (80 µA: n = 8, 40 µA: n = 8, sham: n = 7, healthy control: n = 7) were chosen for the corridor test and the tDCS session. The lesioned rats exhibited increased ipsilateral bias 4 weeks after the lesion surgery (P < 0.01), and the anodal tDCS with the active electrode on the lesioned side relieved the ipsilateral bias significantly (P < 0.01) immediately after the surgery and the improvement lasted for nearly 1 day. The rats in the group of 80 µA exhibited more significant changes than the 40 µA group after one day. After all the experiments, the histological process showed no neurotrauma led by the tDCS. In conclusion, the modulatory function of the cortical excitability of the tDCS may awaken the compensatory mechanisms and the response mechanisms which modulate the loss of the brain function. Further studies should be done to provide more evidence about the assumption.

Protective effects of scutellarin and breviscapine on brain and heart ischemia in rats.

Scutellarin is an active molecule existing in Erigeron breviscapus (vant.) Hand-Mazz. The present work was designed to study the antiischemic effects of scutellarin and its mixture with another substance, breviscapine, in male Sprague-Dawley (SD) rats. Ligature of left anterior descending arteries was performed to induce acute myocardial infarction (MI), and the middle cerebral artery occlusion was created to induce focal cerebral ischemia. The MI size was significantly reduced by scutellarin (15 and 50 mg/kg) but not by breviscapine (5 to 50 mg/kg); the effect of scutellarin on the anti-MI was dose-dependent. Compared with control group, scutellarin (50 mg/kg) reduced the myocardium cell apoptosis in MI rats. The two drugs together (5 to 50 mg/kg) significantly reduced infarction size in focal brain ischemic rats (P < 0.05). There were no significant differences among the 3 dosages in breviscapine-treated rats, and the effect of scutellarin on the anticerebral ischemia was dose-dependent. The results demonstrate that the protective effects of scutellarin on cardiovascular and cerebrovascular ischemia were better than its mixture, breviscapine, in rats.