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Search Results: 1 - 10 of 10691 matches for " Guanhua Du "
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Modern Drug Screening Techniques Approach on CMM

Du Guanhua,

世界科学技术-中医药现代化 , 2000,
Abstract: 近年来,随着科学技术的进步,药物筛选技术发生了巨大变化,出现了以快速、微量、大规模为特点,应用多种先进技术手段的高通量药物筛选方法。应用现代科学技术进行中药现代化研究,是促进中药现代化研究的重要途径之一。本文通过介绍最新技术,讨论了药物筛选新技术在中药现代化研究中的应用,主要探讨了在中药活性成分、中药理论、中药复方、中药作用机制等方面的研究中,药物筛选新技术的应用可能性和已有的尝试,从方法学的角度为中药现代化研究提供新的思路,供研究人员参考。
Fluorescence Resonance Energy Transfer Assay for High-Throughput Screening of ADAMTS1 Inhibitors
Jianhao Peng,Lili Gong,Kun Si,Xiaoyu Bai,Guanhua Du
Molecules , 2011, DOI: 10.3390/molecules161210709
Abstract: A disintegrin and metalloprotease with thrombospondin type I motifs-1 (ADAMTS1) plays a crucial role in inflammatory joint diseases and its inhibitors are potential candidates for anti-arthritis drugs. For the purposes of drug discovery, we reported the development and validation of fluorescence resonance energy transfer (FRET) assay for high-throughput screening (HTS) of the ADAMTS1 inhibitors. A FRET substrate was designed for a quantitative assay of ADAMTS1 activity and enzyme kinetics studies. The assay was developed into a 50-μL, 384-well assay format for high throughput screening of ADAMTS1 inhibitors with an overall Z’ factor of 0.89. ADAMTS1 inhibitors were screened against a diverse library of 40,960 total compounds with the established HTS system. Four structurally related hits, naturally occurring compounds, kuwanon P, kuwanon X, albafuran C and mulberrofuran J, extracted from the Chinese herb Morus alba L., were identified for further investigation. The results suggest that this FRET assay is an excellent tool, not only for measurement of ADAMTS1 activity but also for discovery of novel ADAMTS1 inhibitors with HTS.
Methyl salicylate 2-O-β-D-lactoside, a novel salicylic acid analogue, acts as an anti-inflammatory agent on microglia and astrocytes
Xi Lan, Rui Liu, Lan Sun, Tiantai Zhang, Guanhua Du
Journal of Neuroinflammation , 2011, DOI: 10.1186/1742-2094-8-98
Abstract: Our studies show that DL0309 significantly inhibits lipopolysaccharide (LPS)-induced release of the pro-inflammatory cytokines IL-6, IL-1β, and TNF-α; and the expression of the inflammation-related proteins iNOS, COX-1, and COX-2 by microglia and astrocytes. At a concentration of 10 μM, DL0309 prominently inhibited LPS-induced activation of NF-κB in glial cells by blocking phosphorylation of IKK and p65, and by blocking IκB degradation.We demonstrate here for the first time that DL0309 exerts anti-inflammatory effects in glial cells by suppressing different pro-inflammatory cytokines and iNOS/NO. Furthermore, it also regulates the NF-κB signaling pathway by blocking IKK and p65 activation and IκB degradation. DL0309 also acts as a non-selective COX inhibitor in glial cells. These studies suggest that DL0309 may be effective in the treatment of neuroinflammatory disorders, including AD.Alzheimer's disease (AD) is a progressive neurodegenerative disorder of the elderly characterized by global deficits in cognition ranging from loss of memory to impaired judgment. It has been hypothesized that early microglial activation in AD delays disease progression by promoting clearance of beta amyloid peptide (Aβ) before formation of senile plaques [1-3]. Microglia are antigen-presenting cells that, upon activation, are capable of phagocytosis and the production of various pro-inflammatory molecules such as nitric oxide (NO) and interleukin-1β (IL-1β) [4]. These molecules are able to destroy pathogens, but can also induce toxicity in neurons, which are compromised in AD. Furthermore, in aged human brain, many microglia are dystrophic, showing morphological features indicative of senescence such as fragmented cytoplasmic processes [5]. Like microglia, chronically activated astrocytes are believed to contribute to AD through production of NO and of various pro-inflammatory cytokines and chemokines. Apart from this, astrocytes become activated around plaques to take up Aβ and neuro
Luteolin Isolated from the Medicinal Plant Elsholtzia rugulosa (Labiatae) Prevents Copper-Mediated Toxicity in β-Amyloid Precursor Protein Swedish Mutation Overexpressing SH-SY5Y Cells
Rui Liu,Fanrui Meng,Li Zhang,Ailin Liu,Hailin Qin,Xi Lan,Lin Li,Guanhua Du
Molecules , 2011, DOI: 10.3390/molecules16032084
Abstract: Luteolin, a 3’,4’,5,7-tetrahydroxyflavone, is a plant flavonoid and pharmacologically active agent that has been isolated from several plant species. In the present study, the effects of luteolin obtained from the medicinal plant Elsholtzia rugulosa and the related mechanisms were examined in an Alzheimer's disease (AD) cell model. In this model, copper was used to exacerbate the neurotoxicity in β-amyloid precursor protein Swedish mutation stably overexpressed SH-SY5Y cells (named “APPsw cells” for short). Based on this model, we demonstrated that luteolin increased cell viability, reduced intracellular ROS generation, enhanced the activity of SOD and reversed mitochondrial membrane potential dissipation. Inhibition of caspase-related apoptosis was consistently involved in the neuroprotection afforded by luteolin. Furthermore, it down-regulated the expression of AβPP and lowered the secretion of Aβ1-42. These results indicated that luteolin from the Elsholtzia rugulosa exerted neroprotective effects through mechanisms that decrease AβPP expression, lower Aβ secretion, regulate the redox imbalance, preserve mitochondrial function, and depress the caspase family-related apoptosis.
The Vasorelaxant Mechanisms of a Rho Kinase Inhibitor DL0805 in Rat Thoracic Aorta
Lili Gong,Jianhao Peng,Lianhua Fang,Ping Xie,Kun Si,Xiaozhen Jiao,Liping Wang,Guanhua Du
Molecules , 2012, DOI: 10.3390/molecules17055935
Abstract: Rho-kinase has been suggested as a potential therapeutic target in the treatment of cardiovascular diseases. The Rho-kinase signaling pathway is substantially involved in vascular contraction. The aim of the present study was to evaluate the vasorelaxant effects of Rho kinase inhibitor DL0805 in isolated rat aortic rings and to investigate its possible mechanism(s). It was found that DL0805 exerted vasorelaxation in a dose-dependent manner in NE or KCl-induced sustained contraction and partial loss of the vasorelaxation under endothelium-denuded rings. The DL0805-induced vasorelaxation was significantly reduced by the nitric oxide synthase inhibitor Nω-nitro-L-arginine methyl ester, the guanylate cyclase inhibitor methylene blue and the cyclooxygenase inhibitor indomethacin. The voltage-dependent K+ channel blocker 4-aminopyridine remarkably attenuated DL0805-induced relaxations. However, the ATP-sensitive K+ channel blocker glibenclamide and Ca2+-activated K+ channel blocker tetraethylammonium did not affect the DL0805-induced relaxation. In the endothelium-denuded rings, DL0805 also reduced NE-induced transient contraction and inhibited contraction induced by increasing external calcium. These findings suggested that DL0805 is a novel vasorelaxant compound associated with inhibition of Rho/ROCK signaling pathway. The NO-cGMP pathway may be involved in the relaxation of DL0805 in endothelium-intact aorta. The vasorelaxant effect of DL0805 is partially mediated by the opening of the voltage-dependent K+ channels.
Salvianolic Acid A Protects the Peripheral Nerve Function in Diabetic Rats through Regulation of the AMPK-PGC1α-Sirt3 Axis
Xiaoyan Yu,Li Zhang,Xiuying Yang,Huakang Huang,Zhonglin Huang,Lili Shi,Hengai Zhang,Guanhua Du
Molecules , 2012, DOI: 10.3390/molecules170911216
Abstract: Salvianolic acid A (SalA) is one of the main efficacious, water-soluble constituents of Salvia miltiorrhiza Bunge. This study investigated the protective effects of SalA on peripheral nerve in diabetic rats. Administration of SalA (0.3, 1 and 3 mg/kg, ig) was started from the 5th week after strepotozotocin (STZ60 mg/kg) intraperitoneal injection and continued for 8 weeks. Paw withdrawal mechanical threshold (PWMT) and motor nerve conduction velocity (MNCV) were used to assess peripheral nerve function. The western blot methods were employed to test the expression levels of serine-threonine liver kinase B1 (LKB1), AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1α), silent information regulator protein3 (sirtuin 3/Sirt3) and neuronal nitric oxide synthase (nNOS) in sciatic nerve. Results showed that SalA administration could increase PWMT and MNCV in diabetic rats; reduce the deterioration of sciatic nerve pathology; increase AMPK phosphorylation level, up-regulate PGC-1α, Sirt3 and nNOS expression, but had no influence on LKB1. These results suggest that SalA has protective effects against diabetic neuropathy. The beneficial effects of SalA on peripheral nerve function in diabetic rats might be attributed to improvements in glucose metabolism through regulation of the AMPK-PGC1α-Sirt3 axis.
Salvianolic Acid A Inhibits PDGF-BB Induced Vascular Smooth Muscle Cell Migration and Proliferation While Does Not Constrain Endothelial Cell Proliferation and Nitric Oxide Biosynthesis
Lan Sun,Rui Zhao,Li Zhang,Tiantai Zhang,Wenyu Xin,Xi Lan,Chao Huang,Guanhua Du
Molecules , 2012, DOI: 10.3390/molecules17033333
Abstract: Proliferation and migration of vascular smooth muscle cells (VSMCs) are critical events in the initiation and development of restenosis upon percutaneous transluminal coronary angioplasty (PTCA). Polyphenols have been suggested to ameliorate post-angioplasty restenosis. Salvianolic A (SalA) is one of the most abundant polyphenols extracted from salvia. In this study, we investigated the effect of salvianolic A (SalA) on the migration and proliferation of VSMCs. We found a preferential interaction of SalA with cellular systems that rely on the PDGF signal, but not on the EGF and bFGF signal. SalA inhibits PDGF-BB induced VSMC proliferation and migration in the concentration range from 0.01 to 0.1 μM. The inhibition of SalA on VSMC proliferation is associated with cell cycle arrest. We also found that SalA inhibits the PDGFRβ-ERK1/2 signaling cascade activated by PDGF-BB in VSMCs. In addition, SalA does not influence the proliferation of endothelial cells, the synthesis of NO and eNOS protein expression. Our results suggest that SalA inhibits migration and proliferation of VSMCs induced by PDGF-BB via the inhibition of the PDGFRβ-ERK1/2 cascade, but that it does not constrain endothelial cell proliferation and nitric oxide biosynthesis. Thus, the present study suggests a novel adjunct pharmacological strategy to prevent angioplasty-related restenosis.
3D-QSAR analysis of a new type of acetylcholinesterase inhibitors
AiLin Liu,HongMei Guang,LiYa Zhu,GuanHua Du,Simon M. Y. Lee,YiTao Wang
Science China Life Sciences , 2007, DOI: 10.1007/s11427-007-0094-1
Abstract: Acetylcholinesterase (AChE) inhibitors are an important class of medicinal agents used for the treatment of Alzheimer’s disease. A screening model of AChE inhibitor was used to evaluate the inhibition of a series of phenyl pentenone derivatives. The assay result showed that some compounds displayed higher inhibitory effects. In order to study the relationship between the bioactivities and the structures, 26 compounds with phenyl pentenone scaffold were analyzed. A 3D-QSAR model was constructed using the method of comparative molecular field analysis (CoMFA). The results of cross-validated R2cv=0.629, non-cross-validated R2=0.972, SE=0.331, and F=72.41 indicate that the 3D-model possesses an ability to predict the activities of new inhibitors, and the CoMFA model would be useful for the future design of new AChE inhibitors.
A Personal View of Ouality Control of Traditional Chinese Medicine

Li Zhonghong,Du Guanhua,

世界科学技术-中医药现代化 , 2004,
Abstract: 本文在对现有的指标成分检测及指纹图谱质量控制模式进行分析的基础上,结合本实验室的研究工作,提出有效成分检控应是中药质量控制的发展方向,并阐述了实施有效成分检控这一质量控制模式的方法与可能性。
重庆南山雾水特性及其对马尾松(Pinus massoniana Lamb)的影响

Du Xiaoming,Liu Houtian,Xing Guanhua,

环境科学学报 , 1988,
Abstract: The characieristics of fog water and its effects on masson pine in Nanshan mountains, Chongqing were studied. The results of fog water analysis showed that it was sulfur acidic fog with an average pH value of 4.5(3.6-5.6). The major components of the fog water were SO2-4, Ca2+and NH4+.The total ionic concentration was 9.3 times of that of the rain water at the same season. There was a large amount of particiulate-matter in the fog water. The pH value of the fog water condensed on the needles of pine decreased to 3.0 or below,indicating possibilities of le aching of Ca2+, Mg2+ and NO3- ions from the needles and the effect on needle chlorophyll. The particulate matter in the fog water might affect the needle, photosynthesis by blocking up the stomas.
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