Selective photodynamic effects on cervical adenocarcinoma cells provided by F127 Pluronic®-based micelles modulating hypericin delivery

Abstract Cervical cancer is a leading cause of death among women. The endocervical adenocarcinoma (ECA) represents an aggressive and metastatic type of cancer with no effective treatment options currently available. We evaluated the antitumoral and anti-migratory effects of hypericin (HYP) encapsulated on Pluronic F127 (F127/HYP) photodynamic therapy (PDT) against a human cell line derived from invasive cervical adenocarcinoma (HeLa) compared to a human epithelial cell line (HaCaT). The phototoxicity and cytotoxicity of F127/HYP were evaluated by the following assays: colorimetric assay, MTT, cellular morphological changes by microscopy and long-term cytotoxicity by clonogenic assay. In addition, we performed fluorescence microscopy to analyze cell uptake and subcellular distribution of F127/HYP, cell death pathway and reactive oxygen species (ROS) production. The PDT mechanism was determined with sodium azide and D-mannitol and cell migration by wound-healing assay. The treatment with F127/HYP promoted a phototoxic result in the HeLa cells in a dose-dependent and selective form. Internalization of F127/HYP was observed mainly in the mitochondria, causing cell death by necrosis and ROS production especially by the type II PDT mechanism. Furthermore, F127/HYP reduced the long-term proliferation and migration capacity of HeLa cells. Overall, our results indicate a potentially application of F127/HYP micelles as a novel approach for PDT with HYP delivery to more specifically treat ECA.

Imperatorin is Transported through Blood-Brain Barrier by Carrier-Mediated Transporters

Imperatorin, a major bioactive furanocoumarin with multifunctions, can be used for treating neurodegenerative diseases. In this study, we investigated the characteristics of imperatorin transport in the brain. Experiments of the present study were designed to study imperatorin transport across the blood-brain barrier both in vivo and in vitro. In vivo study was performed in rats using single intravenous injection and in situ carotid artery perfusion technique. Conditionally immortalized rat brain capillary endothelial cells were as an in vitro model of blood-brain barrier to examine the transport mechanism of imperatorin. Brain distribution volume of imperatorin was about 6 fold greater than that of sucrose, suggesting that the transport of imperatorin was through the blood-brain barrier in physiological state. Both in vivo and in vitro imperatorin transport studies demonstrated that imperatorin could be transported in a concentration-dependent manner with high affinity. Imperatorin uptake was dependent on proton gradient in an opposite direction. It was significantly reduced by pretreatment with sodium azide. However, its uptake was not inhibited by replacing extracellular sodium with potassium or N-methylglucamine. The uptake of imperatorin was inhibited by various cationic compounds, but not inhibited by TEA, choline and organic anion substances. Transfection of plasma membrane monoamine transporter, organic cation transporter 2 and organic cation/carnitine transporter 2/1 siRNA failed to alter imperatorin transport in brain capillary endothelial cells. Especially, tramadol, clonidine and pyrilamine inhibited the uptake of [3H]imperatorin competitively. Therefore, imperatorin is actively transported from blood to brain across the blood-brain barrier by passive and carrier-mediated transporter.

Effect of synchronous perfusion of NaN3 in changes in content of cholinergic neurotransmitter in medial prefrontal cortex and hippocampal extra-cellular fluid / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of synchronous perfusion of specific respiratory chain complex IV inhibitor sodium azide (NaN3) in brain on rat ventromedial prefrontal cortex (mPFC) and acetylcholine (ACh) and choline (Ch) contents in hippocampal extra-cellular fluid, and establish the AD rat model induced by mitochondrial acute injury.</p><p><b>METHOD</b>The synchronous dual-probe dual-channel brain microdialysis sampling technology was applied to synchronously perfuse modified Ringer's solution containing NaN3 (50 micro mol L-1) and neostigmine (2 micro mol L-1) into mPFC and hippocampus of conscious, freely moving normal rats, and continuously collect dialysates from different encephalic areas. Dynamic contents of ACh and Ch were determined by high performance liquid chromatography-post-column immobilized enzyme reactor-electrochemical process.</p><p><b>RESULT</b>ACh and Ch contents in mPFC extracellular fluid of normal rats were higher than that in hippocampus. During the process of perfusion, NaN3 could significantly reduce ACh in mPFC/hippocampal extra-cellular fluid, but remarkably increase Ch, and constantly inhibit the recovery of ACh and Ch contents in mPFC/hippocampus.</p><p><b>CONCLUSION</b>The synchronous perfusion of NaN3in rat mPFC and hippocampus can injure functions of the cholinergic nerve projection area, and cause the acute AD model with ACh and Ch metabolic disorders. This model can be used in pathogenetic and pharmacological studies.</p>

[Effect of sodium azide on sperm parameters and the serum levels of testosterone, LH and FSH in adult male mice]

Sodium azide is a chemical and toxic compound. The aim of this study was to evaluate the effects of sodium azide on the viability of sperms and the serum levels of testosterone, LH and FSH in mature male laboratory small mice. In this experimental study, 50 Balb/C male mice weighing 20-25g were divided into five groups [10 mice in each group]. The animals were prescribed sodium azide for 60 days. Alternatively 5, 10 and 20 milligrams per kilogram of body weight of sodium azide were fed to the animals in the experimental groups 1, 2 and 3. After the completion of treatment, serum values of testosterone, LH and FSH were measured. The viability of sperms was also studied. The number of sperms in three experimental groups showed significant decrease compared to the control and sham groups [p<0.001]. Serum value of testostrone hormone showed dose- dependently significant decrease compared to the control and sham groups. The serum level of FSH in the experimental groups did not show any significant change compared to the control and sham groups. But, the serum level of LH in experimental groups receiving sodium azide 10, 20 mg/kg increased significantly compared to the control and sham groups [p<0.01]. It seems sodium azide reduces serum level of testosterone and the number of sperms under the process of spermatogenesis in the animals

Expression and Activity of the Na-K ATPase in Ischemic Injury of Primary Cultured Astrocytes

Astrocytes are reported to have critical functions in ischemic brain injury including protective effects against ischemia-induced neuronal dysfunction. Na-K ATPase maintains ionic gradients in astrocytes and is suggested as an indicator of ischemic injury in glial cells. Here, we examined the role of the Na-K ATPase in the pathologic process of ischemic injury of primary cultured astrocytes. Chemical ischemia was induced by sodium azide and glucose deprivation. Lactate dehydrogenase assays showed that the cytotoxic effect of chemical ischemia on astrocytes began to appear at 2 h of ischemia. The expression of Na-K ATPase alpha1 subunit protein was increased at 2 h of chemical ischemia and was decreased at 6 h of ischemia, whereas the expression of alpha1 subunit mRNA was not changed by chemical ischemia. Na-K ATPase activity was time-dependently decreased at 1, 3, and 6 h of chemical ischemia, whereas the enzyme activity was temporarily recovered to the control value at 2 h of chemical ischemia. Cytotoxicity at 2 h of chemical ischemia was significantly blocked by reoxygenation for 24 h following ischemia. Reoxygenation following chemical ischemia for 1 h significantly increased the activity of the Na-K ATPase, while reoxygenation following ischemia for 2 h slightly decreased the enzyme activity. These results suggest that the critical time for ischemia-induced cytotoxicity of astrocytes might be 2 h after the initiation of ischemic insult and that the increase in the expression and activity of the Na-K ATPase might play a protective role during ischemic injury of astrocytes.

Sodium azide mutagenesis resulted in a peanut plant with elevated oleate content

Screening of peanut seeds resulting from 0.39 percent sodium azide treatment with NIRS calibration equation for bulk seed samples identified a plant with more than 60 percent oleate. Oleate content in individual seeds of the plant, as predicted by NIRS calibration equation for intact single peanut seeds, ranged from 50.05 percent ~ 68.69 percent. Three seeds with >60 percent oleate thus identified were further confirmed by gas chromatography. Multiple sequence alignments of the FAD2B gene from Huayu 22 (wild type) and peanut seeds with elevated oleate (mutant type) revealed a C281T transition in the coding region causing an I94T substitution in the oleoyl-PC desaturase, which may be responsible for reduction in the enzyme activity.

Astaxanthin inhibits sodium azide-induced cytotoxicity in hepatocyte L-02 cells probably by H+ transferring function / 药学学报

This study is to investigate the protective effect of astaxanthin against injured hepatocyte L-02 cells induced by sodium azide (NaN3) and reveal the possible mechanisms. Hepatocyte L-02 cells were exposed to 100 mmol.L-1 NaN3 with various concentrations of astaxanthin pre-incubated, then the cell viability was measured by MTT method; The level of reactive oxygen species (ROS) was determined by DCFH-DA method; The changes of mitochondrial membrane potential (MMP) and apoptosis ratio were detected by JC-1 method and Annexin V-FITC/PI double stain method, respectively. Results showed that after cells were exposed to 100 mmol.L-1 NaN3 for 3 hours, the cell viability significantly decreased; ROS level and the percentage of late phase apoptosis increased obviously; MMP was also declined. When cells were pretreated with astaxanthin, the cell damage and late phase apoptosis ratio reduced and MMP was maintained. However, the level of ROS showed insignificant decrease (P>0.05). The beneficial concentration of astaxanthin in improving cell viability and MMP was not in a dose dependent manner and the most effective of which was 0.10 nmol.L-1 (P<0.01). In order to reveal its possible non-antioxidant mechanism, mitochondrial membrane was imitated and H+ transferring function of astaxanthin was also detected by bilayer lipid membrane (BLM) method. Results showed that 2.0% astaxanthin could transfer H+ efficiently. These suggested the mechanisms of astaxanthin in protection of hepatocyte L-02 cells not via its ROS quenching capability but via its H+ transferring function, which improved the mitochondrial function and had the sequence biology effects.

Estudo do reparo das lesões induzidas no DNA de Escherichia coli pela radiação ultravioleta C (UVC) / Study of repair of induced lesions in the DNA of Escherichia coli by ultraviolet C (UVC)

Didaticamente, podemos dividir o espectro da radiação ultravioleta (UV) em três faixas: UVA (400 a 320 nm), UVB (320 a 290 nm) e UVC (290 a 100 nm). Apesar do UVC ou UV-curto ser eficientemente filtrado pela camada de ozônio da Terra e sua atmosfera, este é uma das faixas do espectro de UV mais usadas para explorar as consequências de danos causados ao DNA, já que a letalidade induzida por este agente está relacionada aos danos diretos no genoma celular, como as lesões dímero de pirimidina, que são letais se não reparadas. Contudo, demonstrou-se que a radiação UVC pode gerar espécies reativas de oxigênio (ERO), como o oxigênio singleto (1O2). Embora, o radical hidroxil (•OH) cause modificações oxidativas nas bases de DNA, alguns trabalhos indicam que o 1O2 também está envolvido nos danos oxidativos no DNA. Esta ERO é produzida por vários sistemas biológicos e reações fotossensibilização, quando cromóforos são expostos à luz visível ou são excitados pela luz UV, permitindo que essa energia possa ser transferida para o oxigênio sendo convertido em 1O2, que é conhecido por modificar resíduos de guanina, gerando 8-oxoG, que caso não seja reparada pode gerar uma transversão GC-TA. O objetivo deste trabalho foi o de elucidar a participação de ERO nos efeitos genotóxicos e mutagênicos gerados pela radiação UVC, assim como as enzimas envolvidas no processo de reparação destas lesões em células de Escherichia coli. Nos ensaios as culturas foram irradiadas com o UVC (254 nm; 15W General Electric G15T8 germicidal lamp, USA). Nossos resultados mostram que o uso de quelantes de ferro não alterou a letalidade induzida pelo UVC. A azida sódica, um captador de 1O2, protegeu as cepas contra os danos genotóxicos gerados pelo UVC e também diminuiu a frequência de mutações induzidas no teste com rifampicina. A reversão específica GC-TA foi induzida mais de 2,5 vezes no ensaio de mutagênese. A cepa deficiente na proteína de reparo Fpg, enzima que corrige a lesão 8-oxoG...

Didactically, we can divide the ultraviolet radiation (UV) spectrum into three bands: UVA (400 to 320 nm), UVB (320-290 nm) and UVC (290-100 nm). Despite the UVC or far-UV be efficiently filtered by Earth´s ozone layer and its atmosphere, this is one of bands of UV spectrum used to explore the consequences of DNA damages, since the UVC-induced lethality is related to direct damage in genome cells, such as pyrimidine dimers, which are lethal if not repaired. However, it was shown that UVC radiation can generate reactive oxygen species (ROS) such as singlet oxygen (1O2). Although hydroxyl radical (•OH) cause oxidative modifications in DNA bases, some works suggests that 1O2 is also involved in oxidative DNA damage. This ROS is produced by several biological systems and photosensitivity reactions when chromophores are exposed to visible light or excited by UV light, allowing that energy can be transferred to the oxygen being converted to 1O2, which is known to modify guanine residues, generating 8-oxoG, if not repaired can lead to a GC-TA transversion. The objective of this work was to elucidate the ROS involvement in the genotoxic and mutagenic effects generated by UVC radiation, as well as the enzymes involved in the repair process of these lesions in Escherichia coli cells. In the assays, cultures were irradiated with UVC (254 nm, 15 W General Electric germicidal lamp G15T8, USA). Our results show that the use of iron chelators did not affect the UVC-induced lethality. The sodium azide, a 1O2 quencher, protected strains against the genotoxic damage produced by UVC and also decreased the frequency of mutations induced in rifampicin assay. Reversal specific GC-TA was induced more than 2.5 fold in the mutagenesis assay. The deficient strain in the repair protein Fpg, an enzyme that corrects 8-oxoG lesions, had less DNA breakage than the wild strain in electrophoresis alkaline assay. The UVC-induced lethality was increased in mutants transformed with the pFPG...

Protective effects of Aloe vera extract on mitochondria of neuronal cells and rat brain / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effects of Aloe vera extract (AV) on mitochondria in rat pheochromocytoma (PC12) cells and rat brain and to study the mechanism of its neuroprotection.</p><p><b>METHOD</b>After treatment, the morphology of PC12 cells was observed under microscope, the activity of mitochondria in PC12 cells was measured by MTT method, and the mitochondrial membrane potential (MMP) in PC12 cells was detected by JC-1 method. The mitochondrial function in rat brain was detected by resazurin method. The production of malondialdehyd (MDA) in rat brain mitochondria was tested by thiobarbaturic acid (TBA) assay.</p><p><b>RESULT</b>AV could improve mitochondrial damage induced by azide sodium (NaN3) in PC12 cells. The viability of PC12 cells treated with NaN364 mmol x L(-1) for 4 h decreased by 47.8%, and AV at 1 and 10 mg x L(-1) could respectively increase the viability of NaN3-treated cells by 16.7% (P < 0.05) and 22.3% (P < 0.01). MMP in PC12 cells in AV 1 and 10 mg x L(-1) group was significantly higher than that of NaN3-treated group (P < 0.05). AV also protected the structure and function of mitochondria in rat brain. AV at 10 mg x L(-1) had protective effect on mitochondria function impair induced by NaN3 (P < 0.01). AV 1 and 10 mg x L(-1) markedly inhibited the lipid peroxidation of brain mitochondria induced by Fe2+ -cysteine (P < 0.05, P < 0.01).</p><p><b>CONCLUSION</b>AV has protective effects on mitochondria of neuronal cells and rat brain.</p>

[Survey of antimutagenic effects of ethanolic extract of propolis by Salmonella typhymurium/microsome]

In this study, antimutagenesis effect of ethanolic extract of propolis against two mutagenic substances named azide sodium and potassium permanganate in the presence and the absence of microsomal homogenate of mouse liver [S9] has been investigated. In this experimental study at first, different concentrations of ethanolic extract of propolis [0.1-5%] for determining minimum inhibitory concentration [MIC] against tester strains were used. Then by Ames test, antimutagenesis effect was assessed in nontoxic extent. In this test, various strains of Salmonella typhymurium were used. Mutant strains [His-] were grown on culture media containing minimum salt and glucose in the presence of mutagen substances above. So only those bacteria that were reversed by mutation [His+] could grow and form colonies on culture media. If antimutagen [EEP] and mutagen substances were gathered, reversed mutation would be reduced and the rate of mutation inhibition could be calculated by means of formula. The differences between the averages of revertants per plate of the sample in relation to the mutagens were analyzed using SPSS software and one-way ANOVA. The resulted MIC values clearly showed that ethanolic extract of propolis at 5% concentration has antibacterial activity against Salmonella typhymurium, but in 0.1-4% concentrations, such effects were not seen. Findings also showed that propolis in such concentrations could neutralize mutagenic effects of those substances in a dose dependent manner. Finally we found that ethanolic extract of propolis that contains different kinds of major and important substances like flavonoids, has good antimutagenic effects and the best concentration for obtaining such effect is in 4% which also was confirmed with microsomal results. The mechanism of antibacterial effect of propolis is complex and it has no analogy to any classic antibiotics, but it should be emphasized that bacterial cell division is inhibited by propolis. Some researchers also argue that propolis could inhibit DNA-dependent RNA polymerase

A Lethal Case of Sodium Azide Ingestion

Sodium azide (NaN3) is a white to colorless, crystalline powder that is highly water soluble, tasteless, and odorless. It is used mainly as a preservative in aqueous laboratory reagents and biologic fluids and also as an automobile airbag gas generant. Although it has caused deaths for decades, the toxic properties and effects of sodium azide in humans remains unknown. A 31-year-old comatose female was transported to the emergency department with an empty bottle labeled sodium azide. She developed cardiac arrest 15 minutes after arrival and expired in spite of 30 minutes of resuscitative effort. Subsequently, resuscitation team members incidentally suffered from sodium azide's exposure and developed eye discomfort, skin rashes parasthesias, pruritus, sore throat, and headache.

Purification and some properties of carbonic anhydrase from Elephas trogontherii (Steppe elephant) bone.

Four isoenzymes of carbonic anhydrase (CA) were purified from Elephas Irogontherii (steppe elephant) bone (approx 0.3-0.5 million years old) from different locations (outer peripheral, cytosolic, inner peripheral and integral) using Sepharose 4B-L-tyrosine sulphanilamide affinity chromatography and their kinetics properties were investigated and compared with known CA isoenzymes. The purification degree of CAs was monitored by SDS-PAGE. Purification fold for outer peripheral, inner peripheral, cytosolic and integral CA was 395.6, 652.8, 1091 and 429.3 and the molecular mass (as determined by gel filtration chromatography) was 37, 36, 35, and 39 kDa, respectively. The optimal temperature for isozymes was 10-20, 30, 30 and 60 degrees C and optimal pH- was between 7.5-11, 7.5-10, 7.5-10 and 7.5 respectively. K(m) values (at optimum pH and 20 degrees C) for p-nitrophenyl acetate as substrate were 4.83, 6.80, 4.525 and 3.86 mM and the Vmax values for the same substrate were 0.00097, 0.0149, 0.00249 and 0.00072 micromol/L*min, respectively. I50 values of isoenzymes for the inhibitors of CA - sulphanilamide, KSCN, acetazolamide and NaN3 were also determined.

Antimutagenic potential of curcumin on chromosomal aberrations in Allium cepa / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Turmeric has long been used as a spice and food colouring agent in Asia. In the present investigation, the antimutagenic potential of curcumin was evaluated in Allium cepa root meristem cells. So far there is no report on the biological properties of curcumin in plant test systems. The root tip cells were treated with sodium azide at 200 and 300 microg/ml for 3 h and curcumin was given at 5, 10 and 20 microg/ml for 16 h, prior to sodium azide treatment. The tips were squashed after colchicine treatment and the cells were analyzed for chromosome aberration and mitotic index. Curcumin induces chromosomal aberration in Allium cepa root tip cells in an insignificant manner, when compared with untreated control. Sodium azide alone induces chromosomal aberrations significantly with increasing concentrations. The total number of aberrations was significantly reduced in root tip cells pretreated with curcumin. The study reveals that curcumin has antimutagenic potential against sodium azide induced chromosomal aberrations in Allium cepa root meristem cells. In addition, it showed mild cytotoxicity by reducing the percentage of mitotic index in all curcumin treated groups, but the mechanism of action remains unknown. The antimutagenic potential of curcumin is effective at 5 microg/ml in Allium cepa root meristem cells.

Characteristics of uptake, transport and efflux of Z- and E-ajoenes in Caco-2 cell monolayers in vitro / 药学学报

The characteristics of uptake, transepithelial transport and efflux of Z- and E-ajoenes isolated from the bulbs of Allium sativum were studied. A human colon cell model Caco-2 cell monolayers in vitro cultured had been applied to study the characteristics of uptake, transepithelial transport and efflux of Z- and E-ajoenes. The quantitative determination of Z- and E-ajoenes was performed by high-performance liquid chromatography. Z- and E-Ajoenes can be detected only in the apical side and can be metabolized, but both compounds can not be transported from apical-to-basolateral and basolateral-to-apical directions in cultured Caco-2 cell monolayers. The metabolism of Z- and E-ajoenes in Caco-2 cell monolayers can be partially inhibited by vitamin C as an anti-oxidant, metyrapone as an inhibitor to subtype CYP3A of cytochrome P450 drug metabolism enzymes, and sodium azide as an inhibitor to ATP production. It is shown that neither Z-ajoene nor E-ajoene can pass through Caco-2 cell monolayers, and that they can be metabolized by the cells. The metabolism might be in correlation with cytochrome P450 drugs metabolism enzymes in Caco-2 cell monolayers.

Purification of a peroxidase from Solanum melongena fruit juice.

Solanum melongena fruit juice contains peroxidase activity of the order of 0.125 IU/mL. A method for the 11-fold purification of the enzyme was developed. The Km values of the peroxidase for the substrates guaiacol and hydrogen peroxide were 6.5 mM and 0.33 mM, respectively. The pH and temperature optima were 5.5 and 84 degrees C, respectively using guaiacol as the substrate. Sodium azide and phenyl hydrazine inhibited the enzyme competitively.

Effect of prepared Polygonum multiflorum on striatum extracellular acetylcholine and choline in rats of intracerebral perfusion with sodium azide / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the protection mechanism of prepared Polygonum multiflorum (PPMT) in rat brain with sodium azide (NaN3) perfusion.</p><p><b>METHOD</b>Rats were divided into six groups: control, model, PPMT, Duxil and PPMT + Duxil groups. The intracerebral microdialysis and high performance liquid chromatography-post column Immobilized enzyme reactor-electrochemical detection were used to continuously measure extracellular acetylcholine (ACh) and choline (Ch) levels in striatum of freely moving awake rats.</p><p><b>RESULT</b>The extracellular Ach, Ch levels of striatum stayed stable in the control group during the whole observing period, but the ACh levels in the model group were lower significant than that in the control group. The Ach levels of three drug groups were respectively higher significant than that of model group at some time points. While the extracellular Ch level in striatum of the model group increased singnificantly compared with the control group. The Ch levels of the three drug groups were lower significant than that of the model group respectively at certain time points. The effects of PPMT were similar with that of Duxil.</p><p><b>CONCLUSION</b>The prepared P. multiflorum can improve the impaired cholinergic nerve function to exert the effects of brain protection by elevating extracellular Ach level and improving uptake of extracellular Ch. It may provide the experimental evidence to support the idea that P. multiflorum could be brain protective drug to treat retrogressive disease such as dementia.</p>

Cellular uptake of magnetic nanoparticle is mediated through energydependent endocytosis in A549 cells

Biocompatible silica-overcoated magnetic nanoparticles containing an organic fluorescence dye, rhodamine B isothiocyanate (RITC), within a silica shell [50 nm size, MNP@SiO2(RITC)s] were synthesized. For future application of the MNP@SiO2(RITC)s into diverse areas of research such as drug or gene delivery, bioimaging, and biosensors, detailed information of the cellular uptake process of the nanoparticles is essential. Thus, this study was performed to elucidate the precise mechanism by which the lung cancer cells uptake the magnetic nanoparticles. Lung cells were chosen for this study because inhalation is the most likely route of exposure and lung cancer cells were also found to uptake magnetic nanoparticles rapidly in preliminary experiments. The lung cells were pretreated with different metabolic inhibitors. Our results revealed that low temperature disturbed the uptake of magnetic nanoparticles into the cells. Metabolic inhibitors also prevented the delivery of the materials into cells. Use of TEM clearly demonstrated that uptake of the nanoparticles was mediated through endosomes. Taken together, our results demonstrate that magnetic nanoparticles can be internalized into the cells through an energy-dependent endosomal-lysosomal mechanism.

A study on the hemolytic properties of Prevotella nigrescens / 대한치과보존학회지

Hemolytic property is a specific feature of bacteria to obtain iron which is essential for its survival in host tissues. Therefore, it is thought to be one of several factors of virulence. The purpose of this study was to investigate the hemolytic properties of Prevotella nigrescens isolated from the teeth diagnosed as pulp necrosis and apical periodontitis under the presence of hemolysin inhibitors such as NaN3 and dithiothreitol, heat, various pH and cultural conditions. The results were as follows; 1. Clinically isolated P. nigrescens strains and standard P. nigrscens ATCC 33563 showed hemolytic activity. 2. P. nigrescens showed higher hemolytic activity against human erythrocytes than sheep or horse erythrocytes. 3. NaN3 and dithiothreitol (DTT) reduced the hemolytic activity of P. nigrescens in a dose dependent manner (p < 0.05). 4. Optimal pH for the maximum hemolytic activity of P. nigrescens was 4.0 and the hemolysin was stable under the 50degrees C, but the hemolytic activity was significantly decreased at 95degrees C. 5. P. nigrescens cultured in 10% CO2 condition showed higher hemolytic activity than the bacteria cultured in the anaerobic condition.

Effects of Tianzhi Keli on extracellular acetylcholine and catecholamine levels in striatum of rats with neuromitochondrial impairment / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effects of Tianzhi Keli (TZ) on acetylcholine (ACh) and catecholamine levels in striatum of rats with neuromitochondrial impairment, and try to find out the neuroprotective mechanism of TZ.</p><p><b>METHOD</b>The microdialysis and high performance liquid chromatography (HPLC)-post column Immobilized enzyme reactor (IMER)-electrochemical detection (ED) were used to establish a model of mitochondrial energy metabolism impairment which induced by perfusion with sodium azide (NaN3), and measure continuously the effects of TZ on extracellular ACh, choline (Ch) and catecholamine of model rats.</p><p><b>RESULT</b>After perfusion with NaN3, ACh, noradrenalin (NE), adrenaline (E), dopamine (DA), 3,4-Dihydroxyphenyl-aletic (DOPAC), and homovanillic acid (HVA) levels were decreased obviously (P < 0.05-0.01), while Ch level was increased distinctly (P < 0.01). Transmitters levels were recovered individually after stop the perfusion with NaN3. TZ can postpone the decrease of ACh and advance the recover of Ch. The effect of TZ coupled with duxil on increasing ACh level is more obviously than effect of TZ or duxil. TZ is also showing a tendency to postpone the decrease of catecholamine and advance its recovery. TZ coupled with duxil can advance the recovery of DOPAC and adjust the metabolic abnormity positively.</p><p><b>CONCLUSION</b>TZ has effect on protecting impairment of choline neurosystem, which induced by damage of mitochondrion and abnormity of energy metabolism; coupled with duxil have synergistic action. TZ also has tendency to protect the impairment of epinephrine and dopamine neurosystem.</p>

Effect of salidroside on mitochondria injury induced by sodium azide / 药学学报

<p><b>AIM</b>To study the protective effect of salidroside on mitochondria injury induced by sodium azide.</p><p><b>METHODS</b>Human neuroblastoma SH-SY5Y cells were exposed to sodium azide with different concentration of salidroside, then cell viability was measured by thiazolyl blue (MTT) method and mitochondrial membrane potential (MMP) was detected by JC-1 method. Protective effect of salidroside against disfunction of mitochondria induced by sodium azide was detected by resazurin method.</p><p><b>RESULTS</b>After exposing to 64 mmol x L(-1) sodium azide for 4 hours, cell viability and MMP of SH-SY5Y cells significantly decreased. When pretreated with salidroside, the cell damage was greatly reduced and the mitochondrial membrane potential was maintained. Furthermore, salidroside can protect function of rat brain mitochondria against damage induced by sodium azide.</p><p><b>CONCLUSION</b>Salidroside was demonstrated to play an important role in improving the function of mitochondria.</p>