Norisoboldine,an Anti-Arthritis Alkaloid Isolated from Radix Linderae,Attenuates Osteoclast Differentiation and Inflammatory Bone Erosion in an Aryl Hydrocarbon Receptor-Dependent Manner

Norisoboldine (NOR), the primary isoquinoline alkaloid constituent of the root of Lindera aggregata, has previously been demonstrated to attenuate osteoclast (OC) differentiation. Accumulative evidence has shown that aryl hydrocarbon receptor (AhR) plays an important role in regulating the differentiation of various cells, and multiple isoquinoline alkaloids can modulate AhR. In the present study, we explored the role of NOR in the AhR signaling pathway. These data showed that the combination of AhR antagonist resveratrol (Res) or α-naphthoflavone (α-NF) nearly reversed the inhibition of OC differentiation through NOR. NOR could stably bind to AhR, up-regulate the nuclear translocation of AhR, and enhance the accumulation of the AhR-ARNT complex, AhR-mediated reporter gene activity and CYP1A1 expression in RAW 264.7 cells, suggesting that NOR might be an agonist of AhR. Moreover, NOR inhibited the nuclear translocation of NF-κB-p65, resulting in the evident accumulation of the AhR-NF-κB-p65 complex, which could be markedly inhibited through either Res or α-NF. Although NOR only slightly affected the expression of HIF-1α, NOR markedly reduced VEGF mRNA expression and ARNT-HIF-1α complex accumulation. In vivo studies indicated that NOR decreased the number of OCs and ameliorated the bone erosion in the joints of rats with collagen-induced arthritis, accompanied by the up-regulation of CYP1A1 and the down-regulation of VEGF mRNA expression in the synovium of rats. A combination of α-NF nearly completely reversed the effects of NOR. In conclusion, NOR attenuated OC differentiation and bone erosion through the activation of AhR and the subsequent inhibition of both NF-κB and HIF pathways.     

Upregulation of progranulin by Helicobacter pylori in human gastric epithelial cells via p38MAPK and MEK1/2 signaling pathway: role in epithelial cell proliferation and migration

Helicobacter pylori is a major human pathogen associated with gastric diseases such as chronic active gastritis, peptic ulcer, and gastric carcinoma. The growth factor progranulin (PGRN) is a secreted glycoprotein that functions as an important regulator of cell growth, migration, and transformation. We aimed to determine the molecular mechanisms by which H. pylori upregulates the expression of PGRN and the relationship between H. pylori infection and production of PGRN in controlling cell proliferation and migration. Levels of PGRN were examined in gastric tissues from patients and in vitro in gastric epithelial cells. Cell proliferation was measured by colony formation assay. Cell migration was monitored by wound healing migration assay. PGRN protein levels were increased in patients with gastritis and gastric cancer tissue. Infection of gastric epithelial cells with H. pylori significantly increased PGRN expression in a time-dependent manner. Blockade of the p38 and MEK1/2 pathway by inhibitor inhibited H. pylori-mediated PGRN upregulation. Activation of p38 and MEK1/2 pathway by H. pylori was also identified. Knockdown of PGRN attenuated the H. pylori-induced proliferative activity and migration of cancer cells. These findings suggest that the upregulation of PGRN in H. pylori-infected gastric epithelial cells may contribute to the carcinogenic process.     

Design of the dike-pond system in the littoral zone of a tributary in the Three Gorges Reservoir, China

The Three Gorges Dam is the greatest water control project in the world with the largest fresh water littoral zone. Emergence of the littoral zone during the growing season provides some plants with the opportunity to complete their growth cycle, but the fluctuating water level also brings about some environmental problems, such as soil erosion, water pollution, and biodiversity reduction. A series of cascading terraced ponds located in the littoral zone of a secondary branch of the Yangtze River at Laotudi Bay was designed to be a dike-pond system for resolving the environmental problems of this special littoral zone while also making use of resources in an eco-friendly manner. The design of the dike-pond system is described in detail in this article, and some monitoring protocols are recommended for evaluating the environmental benefits of the system. The economic value of the dike-ponds was estimated to be about ¥125,986. Due to the ecological management mode adopted, 14 species of wild aquatic plants and 6 species of wading birds were found in the dike-pond system, in contrast to 9 species of wild aquatic plants and 3 species of wading birds in a comparable conventional farming area. It is hoped that dike-pond ecological engineering will be instrumental in reducing water pollution and increasing biodiversity in the littoral zone of the Three Gorges Reservoir.     

Analysis of fatty acids in A. szechenyianum Gay. by microwave‐assisted extraction and gas chromatography‐mass spectrometry

Introduction – Aconitum szechenyianum Gay. is a traditional Chinese medicinal herb with the detumescent and styptic effects and antitumor activity. There have been only a few researches on its chemical components, but no detailed report has appeared on its fatty acids. Objective – To develop a simple and effective method for the extraction of fatty acids from A. zechenyianum Gay. and then to investigate the fatty acid components. Methodology – Microwave‐assisted extraction (MAE) was optimized with response surface methodology, and the fatty acid compositions of extract were determined by GC–MS with previous derivatisation to fatty acid methyl esters (FAMEs). The results were compared with that obtained by classical Soxhlet extraction (SE). Results – Compared with SE, MAE showed significantly higher fatty acid yields, shorter extraction time, and lower energy and solvent consumption. The major fatty acids in A. szechenyianum Gay. are linoleic acid, palmitic acid, linolenic acid, oleic acid and stearic acid, and the unsaturated fatty acids occupy 66.4% of the total fatty acids. Copyright © 2010 John Wiley & Sons, Ltd.     

Carbon nanotube powders as electrode modifier to enhance the activity of anodic biofilm in microbial fuel cells

Carbon nanotube (CNT) is a promising electrode material and has been used as an anode modifier in microbial fuel cells (MFCs). In this study, a new method of simultaneously adding CNT powders and Geobacter sulfurreducens into the anode chamber of a MFC was used, aiming to form a composite biofilm on the anode. The performance of MFCs such as startup time and steady-state power generation was investigated under conditions of different CNT powders dosages. Results showed that both the startup time and the anodic resistance were reduced. The optimal dosage of CNT powders pre-treated by acid was 4 mg/mL for the anode chamber with an effective volume of 25 mL. The anodic resistance and output voltage of the MFC with CNT powders addition were maintained around 180 Ω and 650 mV during 40 days operation, while those of the MFC without CNT powders addition increased from 250 Ω to 540 Ω and decreased from 630 mV to 540 mV, respectively, demonstrating that adding CNT powders helped stabilize the anodic resistance, thus the internal resistance and power generation during long-term operation. Based on cyclic voltammogram, the electrochemical activity of anodic biofilm was enhanced by adding CNT powders, though no significant increase of the biomass in anodic biofilm was detected by phospholipids analysis. There was no remarkable change of ohmic resistance with an addition of CNT powders revealed by current interrupt method, which indicated that the rate of mass transfer might be promoted by the presence of CNT powders.     

Indication of intracellular physiological pH changes by L-cysteine-coated CdTe quantum dots with an acute alteration in emission color

A novel quantum dots (QDs) based biosensor was developed to monitor physiological pH changes in both fixed and living cells by means of pH-dependent emission color of the QDs. In our system, the nominally single-sized colloidal solution samples of the L-cysteine-capped CdTe QDs with intrinsically broadened size distributions were prepared by employing aqueous synthesis technique. The quench of fluorescence intensities of the QDs with a 16 nm red shift of the emission maximum and a color change from green to yellow was observed with a slight pH decrease (from 7.0 to 6.8) in the system. This pH-dependent emission could be attributed to the efficient exciton energy transfer from smaller QDs to larger ones, which was controlled by electrostatic-tuned aggregation/disaggregation (low/high pH values) processes of the QDs. In addition to high stability, the emission shift of the QDs was reversible for at least one cycle under optimal conditions. Our pH biosensor may find potential application for monitoring the intracellular pH changes in both physiological and pathological conditions.