GK-2 Reduces Death of Cultured Granule Neurons in Cerebellum Induced by the Toxic Effects of Zinc Ions.

Peptide mimetic of nerve growth factor GK-2 in a dose of 1-2 mg/liter improves survival of cultured rat cerebellar granule neurons exposed to the cytotoxic effect of zinc ions, but has no protective effect against copper ion cytotoxicity. Experiments on cultured rat hippocampal slices demonstrated that GK-2 did not affect reactivity of pyramidal neurons and long-term potentiation in the hippocampal field CA1 and the probability of glutamate release from presynaptic terminals in the synapses of the CA3-CA1 fields. The results suggest that GK-2 does not affect the functional properties of synaptic transmission under normal conditions, but protects neurons from the toxic effects of zinc, which creates prerequisites for GK-12 use in the treatment of neurodegenerative diseases.

The immediate influence of deltamethrin on ion transport through rabbit skin. An in vitro study.

Deltamethrin can be absorbed into the respiratory tract, the gastrointestinal tract and through the skin. The study was designed to assess the effect of deltamethrin on electrophysiological parameters of rabbit's skin, studied in vitro, to identify the mechanism of action and effects of short-term dermal exposure to deltamethrin. The objective of the study was to investigate changes in electrophysiological parameters after exposure to 0.01 M deltamethrin under unchanged conditions, in the presence of amiloride (sodium transport blocker) and bumetanide (chloride transport blocker). Exposure to deltamethrin reduced the electrophysiological reaction of examined tissue in unchanged conditions and during the sodium reabsorption phase but did not influence the chloride ion secretion phase. The presented data show that the pyrethroide affects transepithelial ion transport in the external layers of the skin. The inhibition of chloride and sodium ions enabled evaluation of the impact of the pesticide on dermal transport.

Manganese chloride induces histone acetylation changes in neuronal cells: Its role in manganese-induced damage.

Manganese neurotoxicity presents with Parkinson-like symptoms, with degeneration of dopaminergic neurons in the basal ganglia as the principal pathological feature. Manganese neurotoxicity studies may contribute to a better understanding of the mechanism of Parkinson's disease. Here, we examined the effects of manganese on histone acetylation, a major epigenetic change in chromatin that can regulate gene expression, chromatin remodelling, cell cycle progression, DNA repair and apoptosis. In this study, we found that manganese chloride (MnCl2) may significantly suppress the acetylation of histone H3 and H4 in PC12 cells and SHSY5Y cells in a time-dependent manner. Then we tested the role of manganese chloride on histone acetyltransferase (HAT) and histone deacetylase (HDAC). The results showed that MnCl2 increased the activity of HDAC but decreased that of HAT in PC12 cells. Further experiments showed that MnCl2 selectively increased the expression levels of HDAC3 and HDAC4 rather than HDAC1 and HDAC2, but decreased that of HAT in PC12 cells and SHSY5Y cells. Pretreatment with the HAT inhibitor anacardic acid (AA) enhanced manganese-induced decrease in cell viability and apoptosis, but HDAC inhibition by TSA drug had an opposite effect in PC12 cells. Collectively, MnCl2 inhibited the acetylation of core histones in cell culture models of PD, and that inhibition of HDAC activity by TSA protects against manganese-induced cell death, indicating that histone acetylation may represent key epigenetic changes in manganese-induced dopaminergic neurotoxicity.

Propofol inhibits carbachol-induced chloride secretion by directly targeting the basolateral K+ channel in rat ileum epithelium.

BACKGROUND: Propofol is a widely used intravenous general anesthetic. Acetylcholine (ACh) is critical in controlling epithelial ion transport. This study was to investigate the effects of propofol on ACh-evoked secretion in rat ileum epithelium. METHODS: The Ussing chamber technique was used to investigate the effects of propofol on carbachol (CCh)-evoked short-circuit currents (Isc). KEY RESULTS: Propofol (10-2 -10-6  mol/L) attenuated CCh-evoked Isc of rat ileum mucosa in a dose-dependent manner. The inhibitory effect of propofol was only evident after application to the serosal side. Pretreatment with tetrodotoxin (TTX, 0.3 µmol/L, n=5) had no effect on propofol-induced inhibitory effect, whereas serosal application of K+ channel inhibitor, glibenclamide, but not, an ATP-sensitive K+ channel inhibitor, largely reduced the inhibitory effect of propofol. In addition, pretreatment with either hexamethonium bromide (HB, nicotinic nACh receptor antagonist) or Cl- channel blockers niflumic acid and cystic fibrosis transmembrane conductance regulator (inh)-172 did not produce any effect on the propofol-induced inhibitory effect. CONCLUSIONS & INFERENCES: Propofol inhibits CCh-induced intestinal secretion by directly targeting basolateral K+ channels.

Characterization of the Anticoagulant and Antithrombotic Properties of the Sphingosine 1-Phosphate Mimetic FTY720.

Sphingosine 1-phosphate (S1P) is a highly active lysophospholipid implicated in various cardiocerebrovascular events such as coagulation, myocardial infarction and stroke. However, as the functional S1P receptor antagonist, whether the S1P mimetic FTY720 can modulate coagulation and/or thrombotic formation remains largely unknown. We investigated the effects of FTY720 on adenosine diphosphate (ADP)-induced platelet aggregation, coagulation parameters and thrombus formation in rats. Pretreatment with FTY720 (2.5 mg/kg) inhibited platelet aggregation induced by ADP, elongated the thrombin time and decreased the fibrinogen levels. However, FTY720 produced no significant effects on the arteriovenous bypass thrombus formation or the FeCl3-induced thrombus formation in the inferior vena cava and the common carotid artery. Our data suggest that FTY720 can exert an inhibitory effect on platelet aggregation and coagulation-related parameters. These characteristics of FTY720 could be useful as an adjunct in the treatment of ischemic diseases such as ischemic stroke and myocardial infarction.

Aluminum trichloride induces bone impairment through TGF-ß1/Smad signaling pathway.

Aluminum (Al) is recognized worldwide as serious inorganic contaminants. Exposure to Al is associated with low BMD and an increased risk of osteoporosis. However, the precise molecular mechanisms remains unclear. Thus, in this study, rats were orally exposed to 0 (control group, CG) and 0.4g/L AlCl3 (AlCl3 treated group, AG) in drinking water for 120days; osteoblasts were treated with AlCl3 (0.12mg/mL) and/or TGF-ß1 (4.5ng/mL) for 24h. We found that AlCl3 decreased the BMD, damaged femoral ultrastructure, decreased the activities of GSH-Px and SOD, and increased the levels of ROS and MDA in bone, decreased the activity of B-ALP and content of PINP, and increased the activity of TRACP-5b and content of NTX-I in serum, decreased mRNA expressions of TGF-ß1, TßRI, TßRII and Smad4, protein expressions of TGF-ß1, p-Smad2/3 and Smad2/3/4 complex, and increased Smad7 mRNA expression in bone and in osteoblasts. Moreover, we found exogenous TGF-ß1 application reversed the inhibitory effect of AlCl3 on osteoblasts activity by activating the TGF-ß1/Smad signaling pathway and increasing the mRNA expressions of ALP and Col I in osteoblasts. These results demonstrate that AlCl3 induces bone impairment through inactivation of TGF-ß1/Smad signaling pathway.

Protein kinase C enhances the swelling-induced chloride current in human atrial myocytes.

Swelling-activated chloride currents (ICl.swell) are thought to play a role in several physiologic and pathophysiologic processes and thus represent a target for therapeutic approaches. However, the mechanism of ICl.swell regulation remains unclear. In this study, we used the whole-cell patch-clamp technique to examine the role of protein kinase C (PKC) in the regulation of ICl.swell in human atrial myocytes. Atrial myocytes were isolated from the right atrial appendages of patients undergoing coronary artery bypass and enzymatically dissociated. ICl.swell was evoked in hypotonic solution and recorded using the whole-cell patch-clamp technique. The PKC agonist phorbol dibutyrate (PDBu) enhanced ICl.swell in a concentration-dependent manner, which was reversed in isotonic solution and by a chloride current inhibitor, 9-anthracenecarboxylicacid. Furthermore, the PKC inhibitor bis-indolylmaleimide attenuated the effect and 4α-PDBu, an inactive PDBu analog, had no effect on ICl.swell. These results, obtained using the whole-cell patch-clamp technique, demonstrate the ability of PKC to activate ICl,swell in human atrial myocytes. This observation was consistent with a previous study using a single-channel patch-clamp technique, but differed from some findings in other species.

Piperazine derivatives as iron chelators: a potential application in neurobiology.

Polysubstituted piperazine derivatives, designed as new iron chelators, were synthesized and fully characterized by nuclear magnetic resonance and mass spectroscopy. Their potential to prevent iron-induced neurotoxicity was assessed using a cellular model of Parkinson disease. We demonstrated their ability to provide sustained neuroprotection to dopaminergic neurons that are vulnerable in this pathology. The iron chelating properties of the new compounds were determined by spectrophotometric titration illustrating that high affinity for iron is not associated with important neuroprotective effects.

Ginkgo biloba extract (Egb761) attenuates zinc-induced tau phosphorylation at Ser262 by regulating GSK3ß activity in rat primary cortical neurons.

In the brain, an excessive amount of zinc promotes the deposition of ß-amyloid proteins and the intraneuronal accumulation of neurofibrillary tangles composed of hyperphosphorylated tau proteins. These consequences are key neuropathological traits that reflect Alzheimer's disease. Egb761, a standardized Ginkgo biloba extract, is a powerful antioxidant known to exhibit neuroprotective actions. In this study, we investigated whether Egb761 can counteract the zinc-induced tau phosphorylation in rat primary cortical neurons. To determine the modification of tau phosphorylation by Egb761 treatment, we conducted Western blot analyses, MTT assay, ROS measurements and immunocytochemistry. We found that zinc-induced tau phosphorylation occurred at Ser262 in a time- and dose-dependent manner while other tau sites were not phosphorylated. Tau phosphorylation at Ser262 was increased 30 min after zinc treatment and peaked 3 h after zinc treatment (control: 100 ± 1.2%, 30 min: 253 ± 2.24%, 3 h: 373 ± 1.3%). Interestingly, Egb761 treatment attenuated the zinc-induced tau hyperphosphorylation at Ser262 in a concentration-dependent manner while the antioxidant N-acetylcysteine showed a similar effect. Furthermore, Egb761 prevented the zinc-induced activation of p38 MAPK and GSK3ß, as well as the zinc-induced increase in ROS production and neuronal cell death. Lithium chloride also inhibited the zinc-induced tau phosphorylation but did not affect ROS levels. These results suggest the potential of Egb761 for inhibiting the zinc-induced tau phosphorylation at Ser262 through its anti-oxidative actions involving the regulation of GSK3ß. Therefore, Egb761 may be a candidate for the treatment of tauopathy present in neurological disorders such as Alzheimer's disease.

Resolving the multifaceted mechanisms of the ferric chloride thrombosis model using an interdisciplinary microfluidic approach.

The mechanism of action of the widely used in vivo ferric chloride (FeCl3) thrombosis model remains poorly understood; although endothelial cell denudation is historically cited, a recent study refutes this and implicates a role for erythrocytes. Given the complexity of the in vivo environment, an in vitro reductionist approach is required to systematically isolate and analyze the biochemical, mass transfer, and biological phenomena that govern the system. To this end, we designed an "endothelial-ized" microfluidic device to introduce controlled FeCl3 concentrations to the molecular and cellular components of blood and vasculature. FeCl3 induces aggregation of all plasma proteins and blood cells, independent of endothelial cells, by colloidal chemistry principles: initial aggregation is due to binding of negatively charged blood components to positively charged iron, independent of biological receptor/ligand interactions. Full occlusion of the microchannel proceeds by conventional pathways, and can be attenuated by antithrombotic agents and loss-of-function proteins (as in IL4-R/Iba mice). As elevated FeCl3 concentrations overcome protective effects, the overlap between charge-based aggregation and clotting is a function of mass transfer. Our physiologically relevant in vitro system allows us to discern the multifaceted mechanism of FeCl3-induced thrombosis, thereby reconciling literature findings and cautioning researchers in using the FeCl3 model.

Mangiferin ameliorates aluminium chloride-induced cognitive dysfunction via alleviation of hippocampal oxido-nitrosative stress, proinflammatory cytokines and acetylcholinesterase level.

Mangiferin is a phytochemical primarily present in the stem, leaves and bark of Mangifera indica. It offers neuroprotection mainly through inhibition of oxidative stress, and decreasing proinflammatory cytokines level in the brain. Aluminium has been reported to cause oxidative stress-associated damage in the brain. In the present investigation, protective effect of mangiferin against aluminium chloride (AlCl3)-induced neurotoxicity and cognitive impairment was studied in male Swiss albino mice. AlCl3 (100 mg/kg) was administered once daily through oral gavage for 42 days. Mangiferin (20 and 40 mg/kg, p.o.) was given to mice for last 21 days of the study. We found cognitive dysfunction in AlCl3-treated group, which was assessed by Morris water maze test, and novel object recognition test. AlCl3-treated group showed elevated level of oxidative stress markers, proinflammatory cytokines level and lowered hippocampal brain-derived neurotrophic factor (BDNF) content. Mangiferin (40 mg/kg) prevented the cognitive deficits, hippocampal BDNF depletion, and biochemical anomalies induced by AlCl3-treatment. In conclusion, our data demonstrated that mangiferin offers neuroprotection in AlCl3-induced neurotoxicity and it may be a potential therapeutic approach in the treatment of oxido-nitrosative stress and inflammation-associated neurotoxicity.

The Blockade of Transmembrane Cl⁻ Flux Mitigates I/R-Induced Heart Injury via the Inhibition of Calpain Activity.

AIMS: The aim of this study was to determine whether calpain is involved in Cl(-)-induced myocardial ischemia/reperfusion (I/R) injury. METHODS: Isolated rat hearts were subjected to either 45 min of global no-flow ischemia followed by reperfusion or successive perfusion with Ca(2+)-free KH solution for 3 min and normal KH solution for 30 min, also known as Ca(2+) paradox. RESULTS: The hearts in the I/R group exhibited increases in myocardial injury area, LDH release, caspase 3 activity and apoptotic indices and a marked decline in cardiac performance. As was the case regarding the effects of MDL 28170, an inhibitor of calpain, treatment with 5 µM NPPB, 5 µM DIDS and low Cl(-) significantly attenuated cardiac injury. Moreover, each of the treatments significantly protected against Ca(2+) overload-induced injury in the setting of Ca(2+) paradox. The Western blot and immunofluorescence data revealed that there was an increase in the percentages of calpain membrane-positive cells and the numbers of fragments resulting from the calpain-mediated proteolysis of α-fodrin in both the I/R and the Ca(2+) paradox, indicating that the activation of calpain occurred. More importantly, these effects were mitigated by the blockade of transmembrane Cl(-) flux, as was accomplished via MDL 28170. CONCLUSION: Our results provide evidence that the blockade of transmembrane Cl(-) flux mitigates I/R-induced cardiac injury via the inhibition of calpain activity. They also indicate that intracellular Ca(2+) overload regulates calpain activation in the setting of Cl(-)-induced injury.

Iron-enhanced coagulation is attenuated by chelation: thrombelastographic and ultrastructural analysis.

Increased circulating ferritin and free iron have been found in a variety of disease states associated with thrombophilia. When blood or plasma is exposed to iron addition, characteristic changes in thrombus formation are observed by scanning electron microscopy, which include fusion of fibrin polymers, matting, and even sheeting of fibrin. A primary mechanism posited to explain iron-mediated hypercoagulability is hydroxyl radical formation and modification of fibrinogen; however, iron has also been demonstrated to bind to fibrinogen. We have recently demonstrated that iron enhances coagulation, manifested as a decrease in the time of onset of coagulation. Using clinically encountered concentrations of iron created by addition of FeCl3 to human plasma, we demonstrated that iron-mediated changes in reaction time determined by thrombelastography or changes in thrombus ultrastructure were significantly, but not completely, reversed by iron chelation with deferoxamine. Thus, reversible iron binding to fibrinogen mechanistically explains a significant portion of coagulation kinetic and ultrastructural hypercoagulability. Further investigation is needed to determine whether residual iron binding or other iron-mediated effects is responsible for hypercoagulability observed after chelation.

Role of propolis (bee glue) in improving histopathological changes of the kidney of rat treated with aluminum chloride.

Humans are frequently exposed to aluminum from various food additives, therapeutic treatments and the environment, and it can be potentially toxic. This study is aimed to elucidate the protective effects of propolis against aluminum chloride (AlCl3 )-induced histopathological and immunohistochemical changes in kidney tissues of rats. Sixty Wistar Albino male rats (average weight 250-300 g) were divided into three equal groups. The first served as a negative control. The second received AlCl3 (34 mg/kg bw, 1/ 25 LD 50). The third were administered AlCl3 (34 mg/kg bw, 1/ 25 LD 50) plus propolis (50 mg/kg bw). Doses were given once daily via a gavage for 8 weeks every day. The results showed that shrunken glomeruli, intraglomerular congestion, loss of apical microvilli, degeneration of mitochondria and widened rough endoplasmic reticulum were also observed in the Proximal Convoluted Tubules of these animals. Treatment with propolis ameliorated the harmful effects of AlCl3 ; this was also proved histopathologically by the noticeable improvement in the renal tissues. There were also significant variations in the expressed of ki-67 and p53 proteins. It can be concluded that propolis may be promising as a natural therapeutic agent in AlCl3 -induced renal toxicity and oxidative stress in rat kidneys.

Towards high-siderophore-content foods: optimisation of coprogen production in submerged cultures of Penicillium nalgiovense.

BACKGROUND: Fungal siderophores are likely to possess atheroprotective effects in humans, and therefore studies are needed to develop siderophore-rich food additives or functional foods to increase the siderophore uptake in people prone to cardiovascular diseases. In this study the siderophore contents of mould-ripened cheeses and meat products were analysed and the coprogen production by Penicillium nalgiovense was characterised. RESULTS: High concentrations of hexadentate fungal siderophores were detected in penicillia-ripened Camembert- and Roquefort-type cheeses and also in some sausages. In one sausage fermented by P. nalgiovense, the siderophore content was comparable to those found in cheeses. Penicillium nalgiovense produced high concentrations of coprogen in submerged cultures, which were affected predominantly by the available carbon and nitrogen sources under iron starvation. Considerable coprogen yields were still detectable in the presence of iron when the fermentation medium was supplemented with the iron chelator Na2-EDTA or when P. nalgiovense was co-cultivated with Saccharomyces cerevisiae. CONCLUSION: These data may be exploitable in the future development of high-siderophore-content foods and/or food additives. Nevertheless, the use of P. nalgiovense fermentation broths for these purposes may be limited by the instability of coprogen in fermentation media and by the ß-lactam production by the fungus.

Mucociliary transport in porcine trachea: differential effects of inhibiting chloride and bicarbonate secretion.

This study was designed to assess the relative importance of Cl(-) and HCO(3)(-) secretion to mucociliary transport rate (MCT) in ex vivo porcine tracheas. MCT was measured in one group of tissues that was exposed to adventitial HCO(3)(-)-free solution while a parallel group was exposed to adventitial HCO(3)(-)-replete solution. After measurement of baseline MCT rates, acetylcholine (ACh) was added to stimulate submucosal gland mucous liquid secretion, and MCT rates were again measured. Before ACh addition, the mean MCT was higher in the HCO(3)(-)-free group (4.2 ± 0.9 mm/min) than in the HCO(3)(-)-replete group (2.3 ± 0.3 mm/min), but this difference was not statistically significant. ACh addition significantly increased MCT in both groups, but ACh-stimulated MCT was significantly lower in the HCO(3)(-)-free group (11.0 ± 1.5 mm/min) than in the HCO(3)(-)-replete group (17.0 ± 2.0 mm/min). A second series of experiments examined the effect on MCT of blocking Cl(-) secretion with 100 µM bumetanide. Before adding ACh, MCT in the bumetanide-treated group (1.0 ± 0.2 mm/min) was significantly lower than in the control group (3.8 ± 1.1 mm/min). ACh addition significantly increased MCT in both groups, but there was no significant difference between the bumetanide-treated group (21.4 ± 1.7 mm/min) and control group (19.5 ± 3.4 mm/min). These results indicate that ACh-stimulated MCT has greater dependence on HCO(3)(-) secretion, whereas the basal MCT rate has greater dependence on Cl(-) secretion.

G0/G1 phase arrest and apoptosis induced by manganese chloride on cultured rat astrocytes and protective effects of riluzole.

Occupational or environmental exposure to excessive Mn would cause manganism, which is resembled Parkinson disease. However, the mechanism underlying manganism is still unknown. It had been documented that astrocytes play important roles in physiological function in brain. Therefore, in the present study, the cultured astrocytes were exposed to 0, 125, 250, and 500 µM MnCl(2), and cell viability, lactate dehydrogenase (LDH) leakage, morphological change, cell cycle progression, and apoptosis were determined. In addition, 100 µM riluzole (a glutamatergic modulator) was pretreated for 6 h before no MnCl(2) exposure or 500 µM MnCl(2) exposure. The results showed that cell viability inhibited, LDH leakage elevated, morphology injured, G(0)/G(1) phase cell cycle arrested, and apoptosis rate increased in a concentration-dependent manner. Further investigation indicated that riluzole pretreatment reversed cytotoxicity, cell cycle aberration, and apoptosis on astrocytes caused by MnCl(2). These results suggested that MnCl(2) could cause cytotoxicity, cell cycle arrest, and apoptosis concentration-dependently; riluzole might antagonize Mn toxicity on astrocytes.

Inappropriate use of D-values for determining biocidal activity of various antimicrobials.

The objective of this study was to investigate the application of established D-value calculations to survival curves for various bacteria using the following antimicrobials: acidified sodium chlorite, triclosan, octanoic acid, and sodium hydroxide. D-values can be calculated in 3 ways, a linear regression, an endpoint calculation, or an average of multiple endpoint calculations. The assumption made in calculating a D-value is that the rate of kill follows 1st-order kinetics under specified treatment conditions. Each antimicrobial solution was challenged with approximately 108 CFU/mL of Staphylococcus aureus, Listeria monocytogenes, Salmonella enterica subsp. enterica, and Escherichia coli independently and in triplicate. Test systems were sampled at each of the 10 time points over a period of 7 min, neutralized, pour plated then incubated at 35 °C for 48 h (AOAC official method 960.09). Survival curves using the log-transformed data were calculated using regression analysis. Correlations coefficients for all linear regression analyses ranged between 0.291 and 0.982, with 6 of the 16 different treatment systems having an R2 value below 0.7. Methods used for calculating D-values should lead to the same result if the survival curve in a given condition is linear. The calculated D-values were different using endpoint analysis (Stumbo method), linear regression, and average of multiple endpoints. This study demonstrates the nonlinearity of inactivation curves of antimicrobials. D-value estimations cannot be reliably used to illustrate biocidal activity in antimicrobial test systems.

Activation of the basolateral membrane Cl- conductance essential for electrogenic K+ secretion suppresses electrogenic Cl- secretion.

Adrenaline activates transient Cl(-) secretion and sustained K(+) secretion across isolated distal colonic mucosa of guinea-pigs. The Ca(2+)-activated Cl(-) channel inhibitor CaCCinh-A01 (30 µm) significantly reduced electrogenic K(+) secretion, detected as short-circuit current (I(sc)). This inhibition supported the cell model for K(+) secretion in which basolateral membrane Cl(-) channels provide an exit pathway for Cl(-) entering the cell via Na(+)-K(+)-2Cl(-) cotransporters. CaCCinh-A01 inhibited both I(sc) and transepithelial conductance in a concentration-dependent manner (IC(50) = 6.3 µm). Another Cl(-) channel inhibitor, GlyH-101, also reduced sustained adrenaline-activated I(sc) (IC(50) = 9.4 µm). Adrenaline activated whole-cell Cl(-) current in isolated intact colonic crypts, confirmed by ion substitution. This adrenaline-activated whole-cell Cl(-) current was also inhibited by CaCCinh-A01 or GlyH-101. In contrast to K(+) secretion, CaCCinh-A01 augmented the electrogenic Cl(-) secretion activated by adrenaline as well as that activated by prostaglandin E(2). Synergistic Cl(-) secretion activated by cholinergic/prostaglandin E(2) stimulation was insensitive to CaCCinh-A01. Colonic expression of the Ca(2+)-activated Cl(-) channel protein Tmem16A was supported by RT-PCR detection of Tmem16A mRNA, by immunoblot with a Tmem16A antibody, and by detection of immunofluorescence in lateral membranes of epithelial cells. Alternative splices of Tmem16A were detected for exons that are involved in channel activation. Inhibition of K(+) secretion and augmentation of Cl(-) secretion by CaCCinh-A01 support a common colonic cell model for these two ion secretory processes, such that activation of basolateral membrane Cl(-) channels contributes to the production of electrogenic K(+) secretion and limits the rate of Cl(-) secretion. Maximal physiological Cl(-) secretion occurs only for synergistic activation mechanisms that close these basolateral membrane Cl(-) channels.

Biochemical and molecular aspects of aluminium chloride-induced neurotoxicity in mice and the protective role of Crocus sativus L. extraction and honey syrup.

Aluminium has been proposed as an environmental factor that may affect several enzymes and other biomolecules related to neurotoxicity and Alzheimer's disease (AD). The promising protective effect of aqueous saffron extract and honey syrup on neurotoxicity induced by aluminuim chloride (AlCl(3)) may be derived from their own antioxidant properties. Balb/c and C57BL/6 mice (35-40 g) were injected with AlCl(3), 40 mg/kg/day for 45 days. Each mice strain was divided into four groups: AlCl(3) treated group, AlCl(3) plus water saffron extract group (administered with saffron extract at 200 mg/kg b.w. once a day for the experimental period), AlCl(3) plus honey syrup group (administered with honey syrup at 500 mg/kg b.w. for 45 days). The control group received no treatment. Oxidative stress and antioxidant status were estimated in the brain and differential display was performed for both mice strains to scan the mRNA in the treated and non treated groups. In addition, the up and down regulated genes were isolated, cloned and sequenced. The sequence analysis was performed and compared with the other genes cited on GenBank. The results show that there was a decrease in the activity of the antioxidant enzymes (P≤0.001) such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the AlCl3 groups of both mice strains. The level of brain thiobarbituric acid reactive substances (TBARS) showed a significant increase (P≤0.001) of lipid peroxidation (LPO) in the AlCl(3) groups. There was an indication of carcinogenicity in the AlCl(3) treated group representing an increase in serum tumor markers such as arginase and a-l-fucosidase. More than 350 band patterns were obtained and about 22 different up-down regulated genes were observed. The sequence analysis of the three selected up-regulated genes revealed that they are similar to B-cell lymphoma 2 (Bcl-2), R-spondin and the inositol polyphosphate 4-phosphatase genes (INPP4B), respectively. The R-spondin gene was up-regulated in all examined animals except the control ones but the other two genes were only induced in the animals treated with AlCl(3) and honey syrup. We conclude that the biochemical and molecular studies showed the neurotoxicity of AlCl(3) in the brains of mice. In addition, there was an ameliorative change with saffron extract and honey syrup against AlCl(3) neurotoxicity. The obtained molecular results suggest that AlCl(3) made induction for BCL-W gene, which is an anticancer gene or belongs to the DNA repair system in the brain cells, as well as for R-spondin and inositol polyphosphate 4-phosphatase genes, which help in cell proliferation.