The Antioxidization Effects of TP-5, Thy(1[Lys23] and Their Spin Labeled Derivatives

TP-5 and Thy(1, synthesized by solid phase synthesis, have the effect to restrain the formation of superoxide anion in xanthine oxidase system in vitro. The formations of lipid peroxide in several organs (such as liver, brain and thymus) of the mice treated with TP-5, TP-5(R, active fragment of Thy(1 and active fragment of Thy(1(R of 10 (g(kg(d-1 for 10 d were decreased. That means these peptides possess the capability of antioxidezation.

Tong xie yao fang relieves irritable bowel syndrome in rats via mechanisms involving regulation of 5-hydroxytryptamine and substance P

AIM: To investigate whether the Chinese medicine Tong Xie Yao Fang(TXYF) improves dysfunction in an irritable bowel syndrome(IBS) rat model. METHODS: Thirty baby rats for IBS modeling were separated from mother rats(1 h per day) from days 8 to 21, and the rectum was expanded by angioplasty from days 8 to 12. Ten normal rats were used as normal controls. We examined the effects of TXYF on defection frequency, colonic transit function and smooth muscle contraction, and the expression of 5-hydroxytryptamine(5-HT) and substance P(SP) in colonic and hypothalamus tissues by Western blot and RT-PCT techniques in both normal rats and IBS model rats with characterized visceral hypersensitivity.in normal rats and 4.5 ± 1.58 in IBS model rats(P < 0.001). However, the defecation frequency was significantly decreased(3.0 ± 1.25 vs 4.5 ± 1.58, P < 0.05), while the time(in seconds) of colon transit function was significantly increased(256.88 ± 20.32 vs 93.36 ± 17.28, P < 0.001) in IBS + TXYF group rats than in IBS group rats. Increased colonic smooth muscle tension and contract frequency in IBS model rats were significantly decreased by administration of TXYF. Exogenous agonist stimulants increased spontaneous activity and elicited contractions of colon smooth muscle in IBS model rats, and all of these actions were significantly reduced by TXYF involving 5-HT and SP down-regulation. CONCLUSION: TXYF can modulate the activity of the enteric nervous system and alter 5-HT and SP activities, which may contribute to the symptoms of IBS.

Synthesis and antitumor activity of N^1-acetylamino-(5-alkyl/aryl-1,3,4-thiadiazole-2-yl)-5-fluorouracil derivatives

A new series of N^1-acetylamino-（5-alkyl/aryl- 1,3,4-thiadiazole-2-yl）-5-fluorouracil derivatives were designed and synthesized. These compounds have not been reported in literature, and their structure chemical were confirmed by IR, ^1H NMR and MS （HRMS）. The results of antitumor inhibitory activity test showed that some compounds possess more potent antitumor inhibitory activity than 5-fluorouracil.

Changes of 5-hydroxytryptamine and tryptophan hydroxylase expression in the ventral horn of spinal cord

Objective To investigate changes of 5-hydroxytryptamine （5-HT） and its synthesis rate-limiting enzyme tryp-tophan hydroxylase （TPH） in the ventral horn of spinal cord after exercise-induced fatigue, and to further discuss the mecha- nism of exercise-induced central fatigue at spinal level. Methods Sixteen healthy adult Wistar rats were randomly divided into 2 groups： exercise-induced fatigue group and control group. Immunohistochemical staining for 5-HT and TPH in the ventral horn were performed and analysized quantitatively. The mean optic densities of 5-HT and TPH positive fibers or terminals were measured by computerized image analyzer. Results Both 5-HT and TPH positive fibers/terminals decreased in the exercise-induced fatigue group. The immunohistochemical staining was weaker and the mean optic densities decreased obviously in the fatigue group compared with those in the control group （P 〈 0.05）. Conclusion 5-HT and TPH in the ventral horn of spinal cord might be involved in exercise-induced fatigue.

Effect of the pineal gland on 5-hydroxytryptamine and γ-aminobutyric acid secretion in the hippocampus of male rats during the summer and winter

Objective:The present study aimed to investigate the effect of seasonal variation on neurotransmitter release in the hippocampus of normal rats and rats with pineal excision.Methods:Two time points,the summer and winter solstice,which are the longest and shortest days of the year,respectively,were selected.Male Spraguee Dawley rats that underwent a sham operation without pineal excision were included as a control group.The concentrations of 5-hydroxytryptamine(5-HT)andγ-aminobutyric acid(GABA)were determined by radioimmunoassays and enzyme-linked immunosorbent assays,respectively.Results:In the winter,the 5-HT and GABA levels in normal rats exhibited a significant difference compared with those in the operation group(P<.01).A difference was also noted in GABA levels between the normal group and the sham operation group(P<.05).The concentrations of 5-HT and GABA in the hippocampal tissues of the normal group exhibited a seasonal rhythm consisting of elevation during the summer and reduction during the winter(P<.01),while the GABA levels in the sham operation group exhibited a significant difference,with elevation during the summer and reduction during the winter(P<.01).In the operation group,GABA showed the same trend(P<.01).Conclusion:The seasonal rhythm of neurotransmitter secretion by the hippocampus(5-HT and GABA)consisted of elevation during the summer and reduction during the winter.During the winter,the pineal gland exhibited a reverse regulatory effect on the secretion of 5-HT and GABA in the hippocampus,and it exhibited seasonal selectivity with regard to the regulation of 5-HT.

Orbitofrontal cortex action of 5-hydroxytryptamine and its receptor in an acute forced swimming stress-induced depression model

BACKGROUND： The orbitofrontal cortex （OFC） is a brain region closely associated with emotion. 5-hydroxytryptamine （5-HT） has been shown to be involved in human depression. OBJECTIVE： To investigate OFC actions and mechanisms of 5-HT and 5-HT1A receptor （5-HT1AR） in stress-induced depression.DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at Laboratory of Neurobiology, College of Life Science, Shaanxi Normal University between May 2006 and March 2008. MATERIALS： 5-HT, p-chlorophenylalanine （PCPA, an inhibitor to tryptophan hydroxylase） and spiperone （5-HT1AR antagonist） were provided by Sigma, USA; rabbit anti-rat 5-HT1AR antibody was provided by Tianjin Haoyang Biological Manufacture. METHODS： A total of 40 male Sprague Dawley rats, aged 3 months, were randomly divided into five groups： control, model, 5-HT, spiperone ＋ 5-HT, and PCPA, with 8 rats in each group. Except for control group, rats in the other four groups were used to establish depression models by forced swimming for 15 minutes. At 30 minutes before forced swimming test, 0.5 pL of 5-HT （12.5 pg/pL）, PCPA （20 pg/pL）, spiperone （1.3 pg/pL） ＋ 5-HT （12.5 pg/pL, 10 minutes later）, and saline were respectively injected into the OFC of 5-HT, PCPA, spiperone ＋ 5-HT, and model groups, respectively. The control group received a saline microinjection into the OFC.MAIN OUTCOME MEASURES： Forced swimming and open field tests were employed to measure animal behaviors, and immunohistochemistry was used to analyze 5-HT1AR expression in the OFC, cingulate cortex, and piriform cortex. RESULTS： （1） Compared with the model group, 5-HT microinjection into the OFC prominently reduced immobility time in the forced swimming test and rearing in open field test （P 〈 0.05）; locomotion and grooming in open field test were increased, although there was no significance （P 〉 0.05）. Furthermore, following PCPA microinjection into the OFC （PCPA ＋ forced swimming stress）, immobility time in forced swimming test increased dramatically （P〈 0.01）, locomotion and rearing in open field test declined （P〈 0.05 and P 〈 0.01, respectively）. Compared with the 5-HT group, 5-HT1AR antagonist （spiperone ＋ 5-HT ＋ forced swimming stress） increased immobility time in forced swimming test （P 〈 0.01）, but decreased locomotion, rearing, and grooming in open field test. （2） Forced swimming stress markedly elevated 5-HT1AR expression in OFC, cingulate cortex, and piriform cortex （P〈 0.05 or P〈 0.01）. CONCLUSION： 5-HT improved stress-induced depression, and 5-HT anti-depression effects are primarily achieved via 5-HT1AR. Stress-induced up regulation of 5-HT1AR expression might be a compensatory mechanism for decreased 5-HT expression.

5-Hydroxytryptamine:a potential therapeutic target in amyotrophic lateral sclerosis

Previous studies have indicated that the pathogenesis of amyotrophic lateral sclerosis(ALS) is closely linked to 5-hydroxytryptamine(5-HT).To investigate this further,we administered 5-HT receptor antagonists to SOD1*G93A transgenic(ALS mouse model) and wide-type mice.This involved intraperitoneal injections of either granisetron,piboserod,or ritanserin,which inhibit the 5-HT3,5-HT4,and 5-HT2 receptors,respectively.The transgenic mice were found to have fewer5-HT-positive cells in the spinal cord compared with wide-type mice.We found that the administration of granisetron reduced the body weight of the transgenic mice,while piboserod and ritanserin worsened the motor functioning,as assessed using a hanging wire test.However,none of the 5-HT receptor antagonists affected the disease progression.We analyzed the distribution and/or expression of TAR DNA binding protein 43(TDP-43) and superoxide dismutase 1 G93A(SOD1-G93A),which fo rm abnormal aggregates in ALS.We found that the expression of these proteins increased following the administration of all three 5-HT receptor antagonists.In addition,the disease-related mislocalization of TD P-43 to the cytoplasm increased markedly for all three drugs.In ce rtain anatomical regions,the 5-HT receptor antagonists also led to a marked increase in the number of astrocytes and microglia and a decrease in the number of neurons.These results indicate that 5-HT deficiency may play a role in the pathogenesis of amyotrophic lateral sclerosis by inducing the abnormal expression and/or distribution of TDP-43 and SOD1-G93A and by activating glial cells.5-HT co uld therefore be a potential therapeutic target for amyotrophic lateral sclerosis.

Role of 5-hydroxytryptamine expression in cerebellar Purkinje cells in obstructive sleep apnea syndrome

In the present study, electrical stimulation to the rat insular cortex induced apnea or respiratory disturbance, reduced amplitude of genioglossal electromyogram, and decreased electromyogram integrals. In addition, arterial blood gas analysis showed arterial blood acidosis, reduced pH values, increased alkali reserve negative values, decreased peripheral blood 5-hydroxytryptamine content, and increased 5-hydroxytryptamine expression in cerebellar Purkinje cells. Following lidocaine injection to block the habenular nucleus, abnormalities in breath, genioglossal electromyogram, and blood gas values disappeared, and peripheral blood 5-hydroxytryptamine content returned to levels prior to electric stimulation. However, 5-hydroxytryptamine expression in cerebellar Purkinje cells remained high. The results suggested that 5-hydroxytryptamine expression in Purkinje cells did not correlate with ventilation function involving insular cortex and habenular nucleus.

5-hydroxytryptamine-mediated apnea caused by the habenular nucleus

5-hydroxytryptamine contributes to the control of activities of the dilator muscle in the upper respiratory tract, and is derived from the raphe nuclei, in which the habenular nucleus exerts a sustaJned inhibitory effect. In the present study, respiratory motion curve of the genJoglossus muscle and peripheral 5-hydroxytryptamine changes were observed following L-glutamate stimulation of the habenular nucleus of adult Wistar rats. Results showed that the rats had apnea and decreased plasma 5-hydroxytryptamine content after the neurons in habenular nucleus were excited. Genioglossus muscle electromyogram amplitude and integral were significantly reduced. The genioglossus myoelectric activity and respiratory motion curve were similar to obstructive sleep apnea syndrome, thus confirming that the habenular nucleus is the key nucleus involved in the pathogenesis of obstructive sleep apnea syndrome, and is the primary regulated center in the raphe nuclei. Stimulation of the habenular nucleus may suppress 5-hydroxytryptamine release and result in apnea, which is similar to obstructive sleep apnea syndrome.

Synthesis and antiangiogenic activities of 5-amino-1,3-dihydro-1,3-dioxo-2H-isoindole-2-propanoic acid derivatives

Based on the structure-activity relationships and antiangiogenic mechanism of RGD-containing peptides, a series of 5-amino- 1,3-dihydro-1,3-dioxo-2H-isoindole derivatives were synthesized. The structures were characterized by ^1H NMR, MS and elementary analysis. There ability to inhibit angiogenesis were evaluated by chick embryo chorioallantoic membrane assay at 10^-5 mol/L. Compounds 7a and 7b displayed obvious antiangiogenic activity.

2D-QSAR Studies on Anthranilic Acid Derivatives: A Novel Class of Allosteric Inhibitors of Hepatitis C NS5B Polymerase

Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic function approximation （GFA） method of variable selection was used to generate the model. Highly statistically significant model with r^2 = 0.966 and r^2cv = 0.951 was obtained when the number of descriptors in the equation was set to 5. High r^2pred value of 0.884 indicates the good predictive power of the best model. Spatial descriptors of radius of gyration （RadOfGration）, molecular volume （Vm）, length of molecule in the z dimension （Shadow-Zlength）, thermodynamic descriptors of the octanol/water partition coefficient （LogP） and molecular refractivity index （MR） showed enormous contributions to HCV NS5B polymerase inhibition. The validation of the model was done by leave-one-out （LOO） test, randomization tests and external test set prediction. The model gives insight on indispensable structural requirements for the activity and can be used to design more potent analogs against HCV NSSB polymerase.

Design,Synthesis,and Biological Evaluation of 5H-Thiazolo[3,2-a]pyrimidine-6-carboxylic Acid Ethyl Ester Derivatives as a Novel Series of Acetylcholinesterase Inhibitors

Acetylcholinesterase inhibitors are the most frequently prescribed anti-Alzheimer＇s drugs. A series of 5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester derivatives as the novel acetylcholinesterase inhibitors was designed based on virtual screening methods. The target compounds were synthesized with Biginelli reaction and Hantzsch-type condensation of dihydropyrimidines with substituted phenacyl chlorides, and were characterized with elemental analysis, IR, MS, ^1H NMR, and ^13C NMR. The biological evaluation against human acetylcholinesterase in vitro indicated all the target compounds show more than 50% inhibition at 10μmol/L by means of the Ellman method. The results provide a starting point for the development of novel drugs to treat Alzheimer＇s disease and lay the foundation of searching for improved acetylcholinesterase inhibitors with the novel scaffolds.

Inhibiting 5-hydroxytryptamine receptor 3 alleviates pathological changes of a mouse model of Alzheimer's disease

Extracellular amyloid beta(Aβ) plaques are main pathological feature of Alzheimer’s disease.However,the specific type of neuro ns that produce Aβ peptides in the initial stage of Alzheimer’s disease are unknown.In this study,we found that 5-hydroxytryptamin receptor 3A subunit(HTR3A) was highly expressed in the brain tissue of transgenic amyloid precursor protein and presenilin-1 mice(an Alzheimer’s disease model) and patients with Alzheimer’s disease.To investigate whether HTR3A-positive interneurons are associated with the production of Aβ plaques,we performed double immunostaining and found that HTR3A-positive interneurons were clustered around Aβ plaques in the mouse model.Some amyloid precursor protein-positive or β-site amyloid precursor protein cleaving enzyme-1-positive neurites near Aβ plaques were co-localized with HTR3A interneurons.These results suggest that HTR3A-positive interneurons may partially contribute to the generation of Aβ peptides.We treated 5.0-5.5-month-old model mice with tro pisetron,a HTR3 antagonist,for 8 consecutive weeks.We found that the cognitive deficit of mice was partially reversed,Aβ plaques and neuroinflammation we re remarkably reduced,the expression of HTR3 was remarkably decreased and the calcineurin/nuclear factor of activated T-cell 4 signaling pathway was inhibited in treated model mice.These findings suggest that HTR3A interneurons partly contribute to generation of Aβ peptide at the initial stage of Alzheimer’s disease and inhibiting HTR3 partly reve rses the pathological changes of Alzheimer’s disease.

Photodynamic Therapy of Cancer Cells with Methanesulfonate Salts of 5-Aminolevulinic Acid and Its Derivatives

A series of 5-aminolevulinic acid and its alkylester methanesulfonates was exploited to photodynamic therapy（PDT） of human lymphocytic cells, U-937 in vitro. The PDT efficiency is influenced by the concentration and incubation time. Generally, for ALA and its alkylester methanesulfonates, the cell survival rate decreases and the accumulation ability of PplX increases with the concentration and incubation time. We found that the longer carbon chain methanesulfonates（C5-S, C6-S, C8-S） exhibit better PDT effect than ALA methanesulfonate. This possibly provides a promising route to the clinical application ofPplX-mediated PDT to cancer cell.

Synthesis and Anti-influenza Virus Activity of Ethyl 6-Bromo-5-hydroxyindole-3-carboxylate Derivatives

A series of ethyl 6-bromo-5-hydroxyindole-3-carboxylate derivatives were synthesized and their in vitro anti-influenza virus activity was evaluated. All the compounds were characterized by 1H NMR and MS.

Design, Synthesis and Antifungal Activity of 6-Fluoro-3,3a,4,5-tetrahydro-2H-pyrazolo[4,3-c]-quinoline-2-carboxamide Derivatives

A series of 6-fluoro-3,3a,4,5-tetrahydro-2H-pyrazolo[4,3-c]quinoline-2-carboxamide derivatives was designed based on the bioisosterism and combination principle in drug design. The target compounds were synthesized from substituted aniline through Michael addition, cyclization, Mannich reaction and condensation with 4-substituted semicarbazides, and the structures were confirmed by mass spectrometry（MS） and 1H NMR. The antifungal assay was carried out in vitro by two-fold dilution. The result shows that all the compounds are of antifungal activities against the tested fungi at different levels.

Synthesis and Metabolism of 5-hydroxytryptamine in Peripheral Circulatory System of Suckling Piglets

[ Objective] To find the rule of 5-hydroxytryptamine （5-HT） synthesis and metabolism in peripheral blood of suckling piglets with aging. [ Method ] All of 15 British Large White pigs at 0, 5 and 15 d of age were selected as experimental animals, and their serumal concentrations of L- tryptophan （L-Trp）, 5-HT and 5-hydroxyindoleacetic acid （5-HIAA） in peripheral circulatory system were determined synchronously by reversed- phase high-performance liquid chromatography method with UV. [ Result] The concentration of L-Trp was （16. 92 ± 1.74） iJmol/L at birth, （59.94 ±10.88） iJmol/L at 5 d of age and （70.42± 6.48） μmol/L at 15 d of age. The concentration of 5-HT was （ 12.85 ± 1.79） iJmol/L at birth, （4.81 ±2.05） ijmol/L at 5 d of age and （5.49±1.09） μmol/L at 15 d of age. While 5-HIAA, the metabolic product of 5-HT, was not detected at all the samples selected. [ Conclusion] The L-Trp concentration of suckling piglets increase significantly with aging （ P 〈0. 05）. While the concentra- tion of 5-HT and the conversion ratio of L-Trp to 5-HT are both highest at birth （P〈0.05） and keep stable at 5 and 15 d of age.

Synthesis, Crystal Structure and Antitumor Activities of N,N,1-Triphenyl-1H-benzo[d]imidazol-5-amine Derivatives

In order to discover the novel antitumor agents,a series of N,N,1-triphenyl-1Hbenzo[d]imidazol-5-amine derivatives were designed and synthesized,and the structures were characterized by IR,H-RMS,1H and 13C NMR.X-ray crystallography showed that 4c is in monoclinic system,space group P1 with a=9.209(2),b=9.533(3),c=14.097(3)?,β=102.069(3)°,V=1202.2(5)?3,Z=2,F(000)=528,μ=1.74 mm–1,S=1.024,the final R=0.0448 and wR=0.1109.The in vitro antitumor activities of target compounds were evaluated by MTT assay against human cancer cell lines K562,HL-60,HeLa and BGC-823.The target compounds demonstrated weak or moderate antitumor activities against these cell lines.

Changes of 5-hydroxytryptamine and dopamine contents in brain microvessels and the influence on cerebral edema at early stage of brain injury

The contents of 5-hydroxytryptamine(5-HT)and dopamine(DA) in the brain microvessels(BMVs) at the early stage of rat brain injury were measured by using high performance liquid chromatography with electrochemical detector(HPLC-ECD) and the influence of the