186 results match your criteria: " The Hong Kong Polytechnic University[Affiliation]"

Tanshinone II A, a multiple target neuroprotectant, promotes caveolae-dependent neuronal differentiation.

Eur J Pharmacol

October 2015

Department of Pharmacology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, PR China. Electronic address:

Neuron loss is one fundamental features of neurodegenerative diseases. Stimulating endogenous neurogenesis, especially neuronal differentiation, might potentially provide therapeutic effects to these diseases. In this study, tanshinone II A (TIIA), a multiple target neuroprotectant, was demonstrated to promote dose-dependent neuronal differentiation in three cell models of immortalized C17.

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Optimization of permethyl ningalin B analogs as P-glycoprotein inhibitors.

Bioorg Med Chem

September 2015

Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China; State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. Electronic address:

In the present study, a total of 9 novel permethyl ningalin B analogs have been synthesized and evaluated for their P-gp modulating activity in a P-gp overexpressed breast cancer cell line LCC6MDR. Among these derivatives, compound 12 with dimethoxy groups at rings A and B and tri-substitution at ring C with ortho-methoxyethylmorpholine, meta-bromo and para-benzyloxy groups displays the most potent P-gp modulating activity with EC50 of 423 nM to reverse paclitaxel resistance. It is non-toxic towards L929 fibroblast with IC50 greater than 100 μM and with selective index greater than 236.

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Sixteen naturally occurring oleanolic acid saponins and their derivatives were synthesized in an efficient and practical strategy, and their inhibitory activities against α-glucosidase and α-amylase were evaluated in vitro. Among all the compounds, 28-O-monoglucoside 8 exhibited remarkably potent inhibitory activity against α-glucosidase with an IC50 value of 87.3 µM, which was fivefold stronger than that of the antidiabetic acarbose.

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Protection against β-amyloid-induced synaptic and memory impairments via altering β-amyloid assembly by bis(heptyl)-cognitin.

Sci Rep

July 2015

Department of Physiology, Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University. Ningbo 315211, China.

β-amyloid (Aβ) oligomers have been closely implicated in the pathogenesis of Alzheimer's disease (AD). We found, for the first time, that bis(heptyl)-cognitin, a novel dimeric acetylcholinesterase (AChE) inhibitor derived from tacrine, prevented Aβ oligomers-induced inhibition of long-term potentiation (LTP) at concentrations that did not interfere with normal LTP. Bis(heptyl)-cognitin also prevented Aβ oligomers-induced synaptotoxicity in primary hippocampal neurons.

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Bis(propyl)-cognitin Prevents β-amyloid-induced Memory Deficits as Well as Synaptic Formation and Plasticity Impairments via the Activation of PI3-K Pathway.

Mol Neurobiol

August 2016

Ningbo Key Laboratory of Behavioral Neuroscience, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, 315211, Ningbo, China.

Bis(propyl)-cognitin (B3C), derived from tacrine linked with three methylene (-CH2-) groups, is a dimerized molecule interacting multiple targets. During the past several years, it has been reported as a promising therapeutic drug for Alzheimer's disease (AD) and other neurodegenerative disorders. However, the therapeutic mechanism of B3C for AD needs further demonstration.

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The cause of Alzheimer's disease (AD) could be ascribed to the progressive loss of functional neurons in the brain, and hence, agents with neuroprotection and neurite outgrowth-promoting activities that allow for the replacement of lost neurons may have significant therapeutic value. In the current study, the neuroprotective and the neurite outgrowth-promoting activities and molecular mechanisms of bis(propyl)-cognitin (B3C), a multifunctional anti-AD dimer, were investigated. Briefly, B3C (24 h pretreatment) fully protected against glutamate-induced neuronal death in primary cerebellar granule neurons with an IC50 value of 0.

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Visual detection of formaldehyde by highly selective fluorophore labeling via gold(III) complex-mediated three-component coupling reaction.

Org Biomol Chem

July 2015

Food Safety and Technology Research Centre, State Key Laboratory of Chirosciences, and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.

A novel method for visual detection of formaldehyde with excellent selectivity via a gold(iii) complex-mediated three-component coupling reaction of resin-linked sterically bulky amines and fluorescent alkynes has been developed.

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We are interested in developing novel natural product-derived P-gp inhibitors to reverse cancer drug resistance. Here, we have synthesized 55 novel derivatives of methylated epigallocatechin (EGC), gallocatechin (GC), and dihydromyricetin (DHM). Three EGC derivatives (23, 35, and 36) and three GC derivatives (50, 51, and 53) are significantly better than epigallocatechin gallate (EGCG) with a relative fold (RF) ranging from 31.

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This paper introduces a detailed method to apply metabolic profiles conducting on tangerine peels (Citrus reticulata 'Dahongpao') at three maturity stages from July to December. Principal component analysis not only demonstrated the metabolic footprints of tangerine peels during ripening but also revealed the compounds (D-limonene and linalool) that mostly contributed to it. Furthermore, some other characteristic compounds were screened to further reveal the chemical features of Pericarpium Citri Reticulatae (PCR) and Pericarpium Citri Reticulatae Viride (PCRV).

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Schisantherin A protects against 6-OHDA-induced dopaminergic neuron damage in zebrafish and cytotoxicity in SH-SY5Y cells through the ROS/NO and AKT/GSK3β pathways.

J Ethnopharmacol

July 2015

State Key Laboratory of Quality Research of Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macao, China. Electronic address:

Ethnopharmacological Relevance: The fruit of Schisandra chinensis (Turcz.) Baill, has been traditionally used in management of liver diseases and ageing associated neurodegeneration. The bioactive compound from this medicinal plant would be valuable for its potential use in prevention and treatment of Parkinson׳s disease.

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Prevalence of antiseptic-resistance genes in staphylococci isolated from orthokeratology lens and spectacle wearers in Hong Kong.

Invest Ophthalmol Vis Sci

May 2015

School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 2Squina Centre for Infection Control, School of Nursing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR.

Purpose: To compare isolation of staphylococci from periorbital tissues and accessories of orthokeratology (ortho-k) lens and spectacle wearers and investigate prevalence of antiseptic-resistance (QAC) genes. To determine minimum inhibitory concentrations (MIC) of antiseptics and antibiotic susceptibility of isolates.

Methods: Staphylococci were isolated from eyelids, eyelashes, and conjunctival sacs of 23 ortho-k lens wearers and 20 spectacle wearers.

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Reaction between CH3O2 and BrO radicals: a new source of upper troposphere lower stratosphere hydroxyl radicals.

J Phys Chem A

May 2015

‡School of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Williamson Building, Oxford Road, Manchester M13 9PL, U.K.

Over the last two decades it has emerged that measured hydroxyl radical levels in the upper troposphere are often underestimated by models, leading to the assertion that there are missing sources. Here we report laboratory studies of the kinetics and products of the reaction between CH3O2 and BrO radicals that shows that this could be an important new source of hydroxyl radicals:BrO + CH3O2 → products (1). The temperature dependent value in Arrhenius form of k(T) is k1 = (2.

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A novel series of tacrine derivatives were designed and synthesized by combining caffeic acid (CA), ferulic acid (FA) and lipoic acid (LA) with tacrine. The antioxidant study revealed that all the hybrids have much more antioxidant capacities compared to CA. Among these compounds, 1b possessed a good ability to inhibit the β-amyloid protein (Aβ) self-aggregation, sub-micromole acetylcholinesterase (AChE)/butyrylcholinesterase (BuChE) inhibitory, modest BACE1 inhibitory.

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Synthesis, biological activity, and biopharmaceutical characterization of tacrine dimers as acetylcholinesterase inhibitors.

Int J Pharm

December 2014

School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region. Electronic address:

Tacrine (THA), as the first approved acetylcholinesterase (AChE) inhibitors for the treatment of Alzheimer's disease (AD), has been extensively investigated in last seven decades. After dimerization of THA via a 7-carbon alkyl spacer, bis(7)-tacrine (B7T) showed much potent anti-AChE activity than THA. We here report synthesis, biological evaluation and biopharmaceutical characterization of six THA dimers referable to B7T.

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An antioxidative galactomannan-protein complex isolated from fermentation broth of a medicinal fungus Cs-HK1.

Carbohydr Polym

November 2014

Department of Applied Biology & Chemical Technology, State Key Laboratory of Chinese Medicine and Molecular Pharmacology in Shenzhen, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China. Electronic address:

A protein-containing polysaccharide, EPS2BW, was fractionated from the exopolysaccharide (EPS) produced by a medicinal fungus Cordyceps sinensis (Cs-HK1). EPS2BW was mainly composed of galactomannan with about 16% (w/w) protein and 50 kDa average molecular weight. The galactomannan part consisted of mannose and galactose at 1.

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Objectives: Constipation has been identified as a worldwide health problem among elderly people. Currently, it is not effectively relieved by the use of laxatives and lifestyle modification. Previous studies reported promising results in managing constipation with auricular acupressure (AA), although its effectiveness was not affirmed.

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The different types of cell death occurring in HCT116 colorectal cancer cell after the treatment of cisplatin, carboplatin, oxaliplatin, DMC, Pt(NH3)2(demethylcantharidin:DMC) and Pt(R,R-1,2-diaminocyclohexane: DACH)(DMC) were examined. Pt(NH3)2(DMC) and Pt(R,R-DACH)(DMC) are the two DMC-integrated platinum complexes:Pt(R,R-DACH)(DMC) with the same Pt moiety as oxaliplatin and Pt(NH3)2(DMC) akin to carboplatin. Using the light scattering properties of cells combined with propidium iodide (PI) red fluorescence to distinguish between early apoptotic and necrotic cells, the results confirmed that apoptosis, which triggered by cisplatin, carboplatin and oxaliplatin, was the major type of cell death, while the major DMC-induced cell death type was necrosis.

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Substantial neuroprotection against K+ deprivation-induced apoptosis in primary cerebellar granule neurons by novel dimer bis(propyl)-cognitin via the activation of VEGFR-2 signaling pathway.

CNS Neurosci Ther

October 2013

Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China; The Hong Kong Polytechnic University, Shenzhen Research Institute, Shenzhen, China.

Background: Neuronal loss via apoptosis in CNS is the fundamental mechanism underlying various neurodegenerative diseases. Compounds with antiapoptotic property might have therapeutic effects for these diseases. In this study, bis(propyl)-cognitin (B3C), a novel dimer that possesses anti-AChE and anti-N-methyl-d-aspartate receptor activities, was investigated for its neuroprotective effect on K(+) deprivation-induced apoptosis in cerebellar granule neurons (CGNs).

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Purpose: Reports on cytotoxic effects of rigid gas-permeable lens multipurpose solutions, which remain important because of increasing popularity of orthokeratology, are limited. This study determined cytotoxic effects of rigid gas-permeable lens multipurpose solutions on human corneal epithelial cells and assessed the proliferation rate at different levels of cell membrane damage.

Methods: The human corneal epithelial cells were exposed to multipurpose solutions containing chlorhexidine gluconate (0.

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We have previously reported that bis(propyl)-cognitin (B3C), similar to memantine (MEM), is an uncompetitive N-methyl-d-aspartate receptor antagonist with fast off-rate property. In the current study, we further demonstrated that in primary cultures of rat cerebellar granule neurons (CGNs), 2h pretreatment of B3C (IC50, 0.45μM) prevented glutamate-induced excitotoxicity 10 times more potently than memantine (IC50, 4.

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Rapid detection and quantitation of ketamine and norketamine in urine and oral fluid by wooden-tip electrospray ionization mass spectrometry.

Analyst

April 2013

State Key Laboratory of Chirosciences, Food Safety and Technology Research Centre and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region, China.

Drug analysis is an indispensable task in controlling drug abuse, which is a serious problem worldwide nowadays. In this study, we report a simple and rapid approach for detection and quantitation of drugs-of-abuse in urine and oral fluid by wooden-tip electrospray ionization mass spectrometry (WT-ESI-MS). We demonstrated that ketamine, one of the most common abused drugs, and its major metabolite, norketamine, in raw urine and oral fluid could be readily detected and quantified by WT-ESI-MS with only little sample preparation and no chromatographic separation, and the analytical performances, including the linear range, accuracy, precision, LOD and LOQ, were well acceptable for analysis of real samples.

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Drynaria fortunei (Kunze) J. Sm. (DF), a Chinese herb commonly used for the treatment of bone fracture, was previously shown to exert anabolic effects on bone.

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Toluene derivatives as simple coupling precursors for cascade palladium-catalyzed oxidative C-H bond acylation of acetanilides.

Chem Commun (Camb)

January 2013

State Key Laboratory of Chirosciences and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.

A palladium-catalyzed cascade cross-coupling of acetanilide and toluene for the synthesis of ortho-acylacetanilide is described. Toluene derivatives can act as effective acyl precursors (upon sp(3)-C-H bond oxidation by a Pd/TBHP system) in the oxidative coupling between two C-H bonds. This dehydrogenative Pd-catalyzed ortho-acylation proceeds under mild reaction conditions.

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Presence of antiseptic resistance genes in porcine methicillin-resistant Staphylococcus aureus.

Vet Microbiol

March 2013

Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. Electronic address:

Numerous studies have documented the presence of methicillin-resistant Staphylococcus aureus (MRSA) in meat-producing animals, which has led to concern about its spread into the community. Disinfectants play an important role in reduction of contamination in both animal husbandry and food-preparation, helping control spread of organisms from foodstuffs, including raw meat. Plasmid-borne antiseptic resistance (AR) genes increasing tolerance to several disinfectants have been reported in S.

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Modulation of telomerase and signal transduction proteins by hexyl-ALA-photodynamic therapy (PDT) in human doxorubicin resistant cancer cell models.

Photodiagnosis Photodyn Ther

September 2012

Medical Laboratory Science Section, Department of Health Technology & Informatics, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region, Kowloon.

Aims: This study employed a doxorubicin resistant (MES-SA-Dx5) human uterine sarcoma cell line and its counterpart (MES-SA), to elucidate the efficacy of aminolevulinic acid-hexylester (hexyl-ALA) mediated PDT at molecular and transcriptional levels.

Methods: Hexyl-ALA generated protoporphyrin IX in both cells were determined by molecular probes using Confocal Laser Scanning Microscopy. The hexyl-ALA-PDT induced signal transduction proteins and mode of cell death were quantitated by CASE ELISA assays and DAPI staining.

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