Understanding and Optimizing Capacitance Performance in Reduced Graphene-Oxide Based Supercapacitors.

Reduced graphene-oxide (RGO)-based electrodes in supercapacitors deliver high energy/power capacities compared to typical nanoporous carbon materials. However, extensive critical analysis of literature reveals enormous discrepancies (up to 250 F g-1 ) in the reported capacitance (variation of 100-350 F g-1 ) of RGO materials synthesized under seemingly similar methods, inhibiting an understanding of capacitance variation. Here, the key factors that control the capacitance performance of RGO electrodes are demonstrated by analyzing and optimizing various types of commonly applied electrode fabrication methods. Beyond usual data acquisition parameters and oxidation/reduction properties of RGO, a substantial difference of more than 100% in capacitance values (with change from 190 ± 20 to 340 ± 10 F g-1 ) is found depending on the electrode preparation method. For this demonstration, ≈40 RGO-based electrodes are fabricated from numerous distinctly different RGO materials via typically applied methods of solution (aqueous and organic) casting and compressed powders. The influence of data acquisition conditions and capacitance estimation practices are also discussed. Furthermore, by optimizing electrode processing method, a direct surface area governed capacitance relationship for RGO structures is revealed.

Astragaloside IV Synergizes with Ferulic Acid to Alleviate Hepatic Fibrosis in Bile Duct-Ligated Cirrhotic Rats.

BACKGROUND: Due to the multi-factorial etiology of hepatic fibrosis, multi-target therapeutics based on combinatory drugs is known to be a promising strategy for the disease. AIMS: The present study attempted to test the hypothesis that astragaloside IV combined with ferulic acid synergistically inhibits activation of hepatic stellate cells in vivo. METHODS: Bile duct-ligated rats were treated with astragaloside IV or/and ferulic acid for 28 days. Liver fibrosis was measured by histological examination. The oxidative stress-related biomarkers were measured with spectrophotometry. Expressions of mRNA and protein were measured by real-time PCR and Western blotting. RESULTS: Bile duct-ligated rat treatment with astragaloside IV and ferulic acid in combination resulted in synergistic alleviation of hepatic fibrosis. Simultaneously, activation of hepatic stellate cells was significantly inhibited by the combination therapy when compared with astragaloside IV or ferulic acid alone. Interestingly, astragaloside IV, but not ferulic acid, induced accumulation of Nrf2 in the nucleus, synthesized antioxidant enzymes through negative regulation of glycogen synthase kinase-3ß, scavenged reactive oxygen species, and, in turn, suppressed hepatic stellate cells activation in bile duct-ligated rats. Conversely, ferulic acid, but not astragaloside IV, suppressed TGF-ß1 and its receptors expression, which resulted in downregulation of Smad3 and Smad4. CONCLUSIONS: These findings suggest that the combination of astragaloside IV and ferulic acid synergistically induces deactivation of hepatic stellate cells through inhibition of the TGF-ß pathway and activation of the Nrf2 pathway, and suggest that combination of astragaloside IV and ferulic acid is a promising candidate for the treatment of hepatic fibrosis.

Marrow adipose tissue in adolescent girls with obesity.

BACKGROUND: Marrow adipose tissue (MAT) is increasingly recognized as an active and dynamic endocrine organ that responds to changes in nutrition and environmental milieu. Compared to normal weight controls, adolescent girls with anorexia nervosa have higher MAT content, which is associated with impaired skeletal integrity, but data are limited regarding MAT content in adolescents with obesity and how this interacts with bone endpoints. OBJECTIVE: To evaluate (i) MAT content in adolescents with obesity compared to normal-weight controls, (ii) the association of MAT with bone endpoints, and (iii) whether these associations of MAT are affected by body weight. METHODS: We assessed MAT, bone endpoints, and body composition in 60 adolescent girls 14-21 years old: 45 with obesity (OB) and 15 normal-weight controls (NW-C). We used (i) DXA to assess areal bone mineral density (aBMD) at the lumbar spine and total hip, and total body fat and lean mass, (ii) proton magnetic resonance spectroscopy (1H-MRS) to assess MAT at the 4th lumbar vertebra and femur, and MRI to assess visceral (VAT) and subcutaneous adipose tissue (SAT), (iii) high resolution peripheral quantitative CT (HR-pQCT) to assess volumetric BMD (vBMD), (iv) individual trabeculae segmentation to evaluate trabecular bone (plate-rod morphology), and (v) finite element analysis to assess stiffness (a strength estimate) at the distal radius and tibia. RESULTS: Groups did not differ for age or height. Weight, BMI, and areal BMD Z-scores at all sites were higher in the OB group (p<0.0001). MAT was lower in OB at the femoral diaphysis (p= <0.0001) and the lumbar spine (p=0.0039). For the whole group, MAT at the lumbar spine and femoral diaphysis was inversely associated with BMI, total fat mass, lean mass, and VAT. Even after controlling for body weight, independent inverse associations were observed of femoral diaphyseal and lumbar MAT with total tibial vBMD, and of lumbar MAT with radial trabecular vBMD. CONCLUSION: Adolescent girls with obesity have lower MAT than normal-weight controls despite having an excess of total body fat. These findings confirm that MAT is regulated uniquely from other adipose depots in obesity. MAT was inversely associated with vBMD, emphasizing an inverse relationship between MAT and bone even in adolescent girls with obesity.

Astragaloside IV and ferulic acid synergistically promote neurite outgrowth through Nrf2 activation.

Recently, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) have nuclear localization and nuclear exclusion signals and shuttle between the cytoplasm and the nucleus. Thus, we hypothesised that astragaloside IV (AS-IV) induction nuclear import of Nrf2 and ferulic acid (FA) inhibition nuclear export of Nrf2 contribute to synergistic antioxidant effects of combination of FA and AS-IV (FA/AS-IV). Here, we have demonstrated that FA/AS-IV enhances neurite outgrowth of PC12 cells challenged with lead acetate (PbAc) via antioxidant properties in a synergistic manner. Concomitantly, FA/AS-IV significantly promotes Nrf2 activation and induces "phase-II'' enzymes during PbAc toxicity, compared with either FA or AS-IV alone. Interestingly, FA but not AS-IV activates the extracellular signal-regulated kinases 1 and 2 (ERK1/2), leading to an increase in both de novo synthesis of Nrf2 and nuclear import of Nrf2. Simultaneously, AS-IV but not FA suppresses Fyn phosphorylation via Akt-mediated inhibition of GSK-3ß, which inhibited nuclear export of Nrf2. Importantly, dual activation of both ERK1/2 and Akt by FA/AS-IV in PC12 cells challenged with PbAc is mediated by independent mechanisms, which are supported by pharmacological inhibitors. Collectively, these results support the notion that the FA/AS-IV may be promising in therapy for lead developmental neurotoxicity. This combination deserves further study in vivo.

Rosmarinic acid attenuates ß-amyloid-induced oxidative stress via Akt/GSK-3ß/Fyn-mediated Nrf2 activation in PC12 cells.

Oxidative stress is an important pathogenic factor in Alzheimer's disease (AD). Recently, nuclear factor E2-related factor 2 (Nrf2) has emerged as a master regulator for the endogenous antioxidant response, and thus represents an attractive therapeutic target against AD. The aim of this study is to test the hypothesis that rosmarinic acid (RosA) attenuates amyloid-ß (Aß)-evoked oxidative stress through activating Nrf2-inducible cellular antioxidant defense system. Here, we reported that RosA attenuated Aß-induced cellular reactive oxygen species (ROS) generation and lipid hydroperoxides (LPO). Interestingly, knockdown of Nrf2 by plasmid-based short hairpin RNA (shRNA) abrogated, at least in part, RosA-mediated neuroprotection in Aß-challenged PC12 cells. Mechanistically, RosA enhanced the nuclear translocation of Nrf2 and binding to antioxidant response element (ARE) core element but did not induced Nrf2 transcription. Simultaneously, RosA induced a set of Nrf2 downstream target genes encoding phase-II antioxidant enzymes. Furthermore, RosA enhanced protein kinase B (Akt) phosphorylation, glycogen synthase kinase-3ß (GSK-3ß) phosphorylation at Ser9, and Fyn phosphorylation. Noteworthy, pharmacological inhibition or gene knockdown studies demonstrated that Akt locate upstream of GSK-3ß and regulate Nrf2 through Fyn in the context of PC12 cells pre-incubated with RosA following exposed to Aß. Conversely, the antioxidant effects of RosA could be blocked by Akt inhibitors LY294002, GSK-3ß inhibitor LiCl, Nrf2 shRNA, or Fyn shRNA in Aß-challenged PC12 cells. Consequently, the antioxidant effects of RosA are mediated predominantly by Akt/GSK-3ß/Fyn pathway through increased activity of Nrf2. These results suggest, although do not prove, that RosA can be a promising candidate for neuroprotective treatment of AD.

Astragaloside IV synergizes with ferulic acid to suppress hepatic stellate cells activation in vitro.

Because hepatic fibrosis usually involves more than one pathological process, combination therapy with modalities that target aberrant signaling cascade in activated hepatic stellate cells (HSCs) represents an alternative strategy. This study evaluates the hypothesis that astragaloside IV (AS-IV) and ferulic acid (FA) synergize to inhibit HSCs activation via simultaneous activating nuclear factor erythroid-2-related factor-2 (Nrf2) and blocking transforming growth factor-ß (TGF-ß) pathways. The combination of FA and AS-IV, hereafter referred to as the AS-IV/FA, at suboptimal concentrations synergistically inhibited HSCs activation, as measured by expressions of α-smooth muscle actin (α-SMA), collagen α type I (Col I) and fibronectin. Nrf2 nuclear accumulation, glutathione (GSH) increase, and reactive oxygen species (ROS) reduction by AS-IV were not potentiated by co-treatment with FA. Similarly, inhibition of TGF-ß1 secretion and Smad activity by FA also was not enhanced by combined treatment with AS-IV. AS-IV/FA synergistically suppresses the p38 mitogen-activated protein kinase (MAPK) activity. Inhibition of HSCs activation by AS-IV/FA could be completely blocked by TGF-ßs-neutralizing antibody plus shRNA-mediated knockdown of Nrf2. Dual blockade of the TGF-ß1/Smad pathway by FA and activation of Nrf2/ARE pathway by AS-IV contributed to the synergistic effects of this combination treatment. These results suggest that combinatorial treatments that target different pathway may afford a more effective strategy to inhibit HSC activation.

ß-Ecdysterone Protects SH-SY5Y Cells Against 6-Hydroxydopamine-Induced Apoptosis via Mitochondria-Dependent Mechanism: Involvement of p38(MAPK)-p53 Signaling Pathway.

Parkinson's disease (PD) is a neurological disorder pathologically characterized by loss of dopaminergic neurons in the substantia nigra. No curative therapy is available for PD. We recently found that phytoestrogen ß-ecdysterone (ß-Ecd) is able to reduce MPP(+)-induced apoptosis in PC12 cells. This study investigated the potential of ß-Ecd to protect against SH-SY5Y cell apoptosis induced by the PD-related neurotoxin 6-hydroxydopamine (6-OHDA) and the underlying mechanism for this cytoprotection. In the present study, pretreatment with ß-Ecd significantly reduced 6-OHDA-induced apoptosis of SH-SY5Y cells by a mitochondria-dependent pathway, as indicated by downregulation of Bax and PUMA (p53 upregulated modulator of apoptosis) expression, suppressing ΔΨm loss, inhibiting cytochrome c release, and attenuating caspase-9 activation. Furthermore, we showed that the inhibition of p38 mitogen-activated protein kinase (p38(MAPK))-dependent p53 promoter activity contributed to the protection of SH-SY5Y cells from apoptosis, which was validated by the use of SB203580 or p38ß dominant negative (DN) mutants. Additionally, knock-down apoptosis signal-regulating kinase 1 (ASK1) by specific shRNA and blockade reactive oxygen species (ROS) by pharmacological inhibitor competently prevented ß-Ecd-mediated inhibition of p38(MAPK) and ASK1 phosphorylation, respectively. These data provide the first evidence that ß-Ecd protects SH-SY5Y cells against 6-OHDA-induced apoptosis, possibly through mitochondria protection and p53 modulation via ROS-dependent ASK1-p38(MAPK) pathways. The neuroprotective effects of ß-Ecd make it a promising candidate as a therapeutic agent for PD.