Isolation of Neuroprotective Anthocyanins from Black Chokeberry (Aronia melanocarpa) against Amyloid-β-Induced Cognitive Impairment

Black chokeberry (Aronia melanocarpa) fruits are rich in anthocyanins, which are vital secondary metabolites that possess antioxidative properties. The aim of this study was to isolate and purify the anthocyanins from black chokeberry by simulated moving bed (SMB) chromatography, and to investigate the neuroprotective effect of SMB purified anthocyanin against Aβ-induced memory damage in rats. The parameters of the SMB process were studied and optimized. Anthocyanin extracts were identified by HPLC and UPLC-QTOF-MS, and antioxidant abilities were evaluated. The Aβ-induced animal model was established by intracerebral ventricle injection in rat brain. Through the SMB purification, anthocyanins were purified to 85%; cyanidin 3-O-galactoside and cyanidin 3-O-arabinoside were identified as the main anthocyanins by UPLC-QTOF-MS. The SMB purified anthocyanins exhibited higher DPPH and ABTS free radical scavenging abilities than the crude anthocyanins extract. Furthermore, rats receiving SMB purified anthocyanins treatment (50 mg/kg) showed improved spatial memory in a Morris water maze test, as well as protection of the cells in the hippocampus against Aβ toxicity. These results demonstrate that anthocyanins could serve as antioxidant and neuroprotective agents, with potential in the treatment of Alzheimer’s disease

Direct Blow-Spinning of Nanofibers on a Window Screen for Highly Efficient PM_2.5 Removal

Particulate matter (PM) pollution has caused many serious public health issues. Whereas indoor air protection usually relies on expensive and energy-consuming filtering devices, direct PM filtration by window screens has attracted increasing attention. Recently, electrospun polymer nanofiber networks have been developed as transparent filters for highly efficient PM_2.5 removal; however, it remains challenging to uniformly coat the nanofibers on window screens on a large scale and with low cost. Here, we report a blow-spinning technique that is fast, efficient, and free of high voltages for the large-scale direct coating of nanofibers onto window screens for indoor PM pollution protection. We have achieved a transparent air filter of 80% optical transparency with >99% standard removal efficiency level for PM_2.5. A test on a real window (1 m × 2 m) in Beijing has proven that the nanofiber transparent air filter acquires excellent PM_2.5 removal efficiency of 90.6% over 12 h under extremely hazy air conditions (PM_2.5 mass concentration > 708 μg/m³). Moreover, we show that the nanofibers can be readily coated on the window screen for pollution protection and can be easily removed by wiping the screen after hazardous days

Tongxinluo attenuates reperfusion injury in diabetic hearts by angiopoietin-like 4-mediated protection of endothelial barrier integrity via PPAR-α pathway

<div><p>Objective</p><p>Endothelial barrier function in the onset and Tongxinluo (TXL) protection of myocardial ischemia/reperfusion (I/R) injury, and TXL can induce the secretion of Angiopoietin-like 4 (Angptl4) in human cardiac microvascular endothelial cells during hypoxia/reoxygenation. We intend to demonstrate whether TXL can attenuate myocardial I/R injury in diabetes, characterized with microvascular endothelial barrier disruption, by induction of Angptl4-mediated protection of endothelial barrier integrity.</p><p>Methods and results</p><p>I/R injury was created by coronary ligation in ZDF diabetic and non-diabetic control rats. The animals were anesthetized and randomized to sham operation or I/R injury with or without the exposure to insulin, rhAngptl4, TXL, Angptl4 siRNA, and the PPAR-α inhibitor MK886. Tongxinluo, insulin and rhAngptl4 have the similar protective effect on diabetic hearts against I/R injury. In I/R-injured diabetic hearts, TXL treatment remarkably reduced the infarct size, and protected endothelial barrier integrity demonstrated by decreased endothelial cells apoptosis, microvascular permeability, and myocardial hemorrhage, fortified tight junction, and upregulated expression of JAM-A, integrin-α5, and VE-cadherin, and these effects of TXL were as effective as insulin and rhAngptl4. However, Angptl4 knock-down with siRNA interference and inhibition of PPAR-α with MK886 partially diminished these beneficial effects of TXL and rhAngptl4. TXL induced the expression of Angptl4 in I/R-injured diabetic hearts, and was canceled by Angptl4 siRNA and MK886. TXL treatment increased myocardial PPAR-α activity, and was abolished by MK886 but not by Angptl4 siRNA.</p><p>Conclusions</p><p>TXL protects diabetic hearts against I/R injury by activating Angptl4-mediated restoration of endothelial barrier integrity via the PPAR-α pathway.</p></div

Identification of endothelial cell apoptosis in the I/R-injured hearts treated with or without TXL by confocal microscopy.

<p>Endothelial cells were identified by red fluorescence (CD34), total cell number was detected by blue fluorescence (DAPI DNA staining), and apoptosis was detected by green fluorescence (TUNEL). Apoptotic endothelial cells were detected and counted by colocalized red and green (displayed as yellow). I/R injury induced significant ECs apoptosis in both MI control and diabetic MI rats (n = 8 in each group). Treatment with insulin, rhAngptl4 or TXL ameliorated ECs apoptosis compared with the diabetic MI controls. Whereas, co-treatment with Angptl4 siRNA partially blocked the beneficial effect of TXL. Administration of the PPARα inhibitor MK886 also reversed the inhibition effect of TXL on ECs apoptosis, but not reduce ECs apoptosis in the rhAngptl4-treated animals. Red arrows indicate endothelial cells and white arrows show apoptotic cells. Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198403#pone.0198403.g001" target="_blank">Fig 1</a>.</p

Evaluation of intramyocardiac hemorrhage in the infarcted hearts treated with or without TXL.

<p>Sections of the hearts were stained with hematoxylin-eosin (n = 8 in each group). DB-sham group has no obvious extravasation of red blood cells in the interstitial space (A). I/R injury induced apparent extravasation of red blood cells into the interstitial space in both DB-MI (B) and non-DB-MI (C) groups. Treatment with insulin (D), rhAngptl4 (E) or TXL (F) greatly decreased extravasation of red blood cells. Combination with angptl4 siRNA canceled the effects of rhAngptl4 (I) and TXL (J). However, combination with MK886 abolished the effect of TXL (L) but not rhAngptl4 (K). Images were taken under a Leica microscope with 40×objective. Black arrows indicate intra-myocardiac hemorrhage. Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198403#pone.0198403.g001" target="_blank">Fig 1</a>.</p

Expression levels of JAM-A, VE-cadherin, and integrin-α5 in the I/R-injured hearts with or without TXL treatment.

<p>I/R injury decreased the expression levels of JAM-A (A), VE-cadherin (B), and Integrin-α5 (C). Pre-treatment with insulin, rhAngptl4, or TXL up-regulated expression levels of JAM-A (A), VE-cadherin (B), and Integrin-α5 (C). Addition of Angptl4 siRNA canceled the effects of TXL-induced up-regulation of JAM-A (A) and VE-cadherin (B), but not Integrin-α5 (C). Co-treatment with MK886 abolished the TXL-upregulated expression of JAM-A (A), VE-cadherin (B), and Integrin-α5 (C). Compared with DB-sham group, *<i>P</i><0.05, ** <i>P</i><0.01; Compared with the DB-MI group, ^†<i>P</i><0.05, ^††<i>P</i><0.01; Compared with the TXL group, ^‡<i>P</i><0.05, ^‡‡<i>P</i><0.01; Compared with the rhAngptl4+siR group, ^§§<i>P</i><0.01. Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198403#pone.0198403.g001" target="_blank">Fig 1</a>.</p

Histopathologic assessments of the area at risk and necrosis in the infarcted hearts treated with or without TXL in the presence or absence of signal regulators.

<p>The area at risk and necrosis was respectively examined by Evans blue and triphenyltetrazolium chloride (TTC) staining (n = 8 in each group). The health myocardium was stained blue by Evans blue, the area at risk (AAR) was not stained by Evans blue. TTC-unstained white myocardium was identified as the area of necrosis (AN). Abbreviations: DB-sham = Diabetic sham; DB-MI = Diabetic MI control; non-DB-MI = non-diabetic MI control; rhAngptl4 = recombinant human Angptl4; rhAngptl4+siCtrl = rhAngptl4+control siRNA; TXL+siCtrl = TXL+control siRNA; rhAngptl4+siR = rhAngptl4+Angptl4 siRNA; TXL+siR = TXL+Angptl4 siRNA.</p

Expression levels of Angptl4 and analysis of PPAR-α activity in the I/R-injured diabetic hearts treated with or without TXL in the presence or absence of signal regulators.

<p>(A) Angptl4 expression was decreased by I/R injury, and pre-treatment with insulin, rhAngptl4, or TXL reverted this effect. Whereas, Angptl4 siRNA and MK886 abolished the TXL-induced upregulation of Angptl4. (B) I/R injury decreased the PPAR-α activity in the I/R-injured myocardium, and even worse in diabetic hearts. Pre-treatment of insulin, rhAngptl4 and TXL increased the PPAR-α activity. Addition of MK886 but not Angptl4 siRNA abolished the TXL-stimulated PPAR-α activation. Compared with the DB-sham group, *<i>P</i><0.05, **<i>P</i><0.01; Compared with the DB-MI group, ^†<i>P</i><0.05, ^††<i>P</i><0.01; Compared with the TXL group, ^‡<i>P</i><0.05, ^‡‡<i>P</i><0.01; Compared with the rhAngptl4+siR group, ^§§<i>P</i><0.01. Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198403#pone.0198403.g001" target="_blank">Fig 1</a>.</p