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.
Alzheimer Disease ; Animals ; Blood-Brain Barrier* ; Brain ; Carotid Arteries ; Cell Membrane ; Choline ; Clonidine ; Endothelial Cells ; In Vitro Techniques ; Injections, Intravenous ; Neurodegenerative Diseases ; Perfusion ; Potassium ; Protons ; Pyrilamine ; Rats ; RNA, Small Interfering ; Sodium ; Sodium Azide ; Sucrose ; Tea ; Tramadol ; Transfection

OBJECTIVETo 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.

METHODThe 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.

RESULTACh 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.

CONCLUSIONThe 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.

Acetylcholine ; metabolism ; Animals ; Choline ; metabolism ; Extracellular Fluid ; drug effects ; metabolism ; Hippocampus ; cytology ; Male ; Neurotransmitter Agents ; metabolism ; Perfusion ; Prefrontal Cortex ; cytology ; Rats ; Rats, Sprague-Dawley ; Sodium Azide ; administration & dosage ; pharmacology ; Time Factors

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.
Adenosine Triphosphatases ; Astrocytes ; Brain Injuries ; Glucose ; Ischemia ; L-Lactate Dehydrogenase ; Neuroglia ; Neurons ; RNA, Messenger ; Sodium Azide

Adult ; Humans ; Male ; Occupational Exposure ; Sodium Azide ; poisoning

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.
Antioxidants ; pharmacology ; Apoptosis ; drug effects ; Cell Line ; Cell Survival ; drug effects ; Hepatocytes ; cytology ; drug effects ; Humans ; Hydrogen-Ion Concentration ; Membrane Potential, Mitochondrial ; drug effects ; Protons ; Reactive Oxygen Species ; metabolism ; Sodium Azide ; toxicity ; Xanthophylls ; pharmacology

OBJECTIVETo 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.

METHODAfter 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.

RESULTAV 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).

CONCLUSIONAV has protective effects on mitochondria of neuronal cells and rat brain.

Aloe ; chemistry ; Animals ; Brain ; drug effects ; metabolism ; Lipid Peroxidation ; drug effects ; Male ; Malondialdehyde ; metabolism ; Mitochondria ; drug effects ; metabolism ; Neurons ; drug effects ; metabolism ; PC12 Cells ; Plant Extracts ; pharmacology ; Plants, Medicinal ; chemistry ; Rats ; Rats, Sprague-Dawley ; Sodium Azide ; pharmacology

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.
Adult ; Air Bags ; Automobiles ; Coma ; Crystallins ; Eating ; Emergencies ; Exanthema ; Eye ; Female ; Headache ; Heart Arrest ; Humans ; Indicators and Reagents ; Pharyngitis ; Pruritus ; Resuscitation ; Sodium ; Sodium Azide

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.
Antioxidants ; pharmacology ; Ascorbic Acid ; pharmacology ; Biological Transport ; drug effects ; Caco-2 Cells ; Cell Membrane ; drug effects ; metabolism ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 CYP3A Inhibitors ; Disulfides ; chemistry ; isolation & purification ; pharmacokinetics ; Enzyme Inhibitors ; pharmacology ; Garlic ; chemistry ; Humans ; Metyrapone ; pharmacology ; Plants, Medicinal ; chemistry ; Sodium Azide ; pharmacology ; Stereoisomerism

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.
Antimutagenic Agents ; pharmacology ; Chromosome Aberrations ; drug effects ; Curcumin ; pharmacology ; Meristem ; drug effects ; genetics ; Mutagens ; toxicity ; Onions ; drug effects ; genetics ; Sodium Azide ; toxicity

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.
Biocompatible Materials/*pharmacokinetics ; Cell Line, Tumor ; Drug Delivery Systems/methods ; Endocytosis/*physiology ; Endosomes/physiology ; Humans ; Lung Neoplasms/drug therapy/*metabolism ; Macrolides/pharmacology ; Microscopy, Confocal ; Microscopy, Electron, Transmission ; Nanoparticles/*administration & dosage ; Sodium Azide/pharmacology ; Sucrose/pharmacology ; Temperature