3,6'-Disinapoyl sucrose alleviates cognitive deficits in APP/PS1 transgenic mice.

Alzheimer's disease (AD) is a neurodegenerative disorder with insidious onset and progressive development. There is an urgent need to find drugs that prevent and slow AD progression. We focus our attention on 3,6'-disinapoyl sucrose (DISS), an oligosaccharide with antidepressant and antioxidant activities. In this work, APP/PS1 transgenic mice were used to explore the neuroprotective impact of DISS to provide new applications for prevention and therapy of AD. This study aims to assess DISS's neuroprotective impact on learning and memory deficits in APP/PS1 transgenic mice using behavioral tests (Morris water maze, novel object recognition test, and passive avoidance test). Morphological alterations of hippocampus neurons were observed by Nissl staining and neuronal apoptosis was assessed by TUNEL assay. By using ELISA, the expressions of inflammatory factors were evaluated, and Western blotting was used to measure the protein expressions of neuron-related regulators in the hippocampus. DISS significantly ameliorated the cognitive disorder in APP/PS1 transgenic mice, reduced apoptosis by decreasing the ratio of Bax/B-cell lymphoma/leukemia-2 (Bcl-2) in hippocampal neurons, and restored the abnormal secretion of inflammatory factors (IL-2, TNF-α, IL-1ß, and IL-6). Moreover, the gavage of high-dose DISS can boost the expressions of CREB/brain-derived neurotrophic factor (BDNF). Overall, our results indicate that DISS improves cognitive function in APP/PS1 transgenic mice by inhibiting neural apoptosis and activating the CREB/BDNF signal pathway.NEW & NOTEWORTHY In this study, for the first time, DISS was used in APP/PS1 transgenic mice to explore its neuroprotective effect. After gavage DISS for 1 mo, the impairment of learning and spatial memory ability and the loss of neurons in APP/PS1 mice were alleviated. DISS reduced a neuroprotective effect in AD mice via decreasing neuronal apoptosis, enhancing the expressions of CREB phosphorylation and BDNF, pointing to DISS as a new therapeutic target for AD.

The immunometabolic reprogramming of microglia in Alzheimer's disease.

Alzheimer's disease (AD) is an age-related neurodegenerative disorder (NDD). In the central nervous system (CNS), immune cells like microglia could reprogram intracellular metabolism to alter or exert cellular immune functions in response to environmental stimuli. In AD, microglia could be activated and differentiated into pro-inflammatory or anti-inflammatory phenotypes, and these differences in cellular phenotypes resulted in variance in cellular energy metabolism. Considering the enormous energy requirement of microglia for immune functions, the changes in mitochondria-centered energy metabolism and substrates of microglia are crucial for the cellular regulation of immune responses. Here we reviewed the mechanisms of microglial metabolic reprogramming by analyzing their flexible metabolic patterns and changes that occurred in their metabolism during the development of AD. Further, we summarized the role of drugs in modulating immunometabolic reprogramming to prevent neuroinflammation, which may shed light on a new research direction for AD treatment.

Protective effects of fisetin in an Aß1-42-induced rat model of Alzheimer's disease.

Alzheimer's disease (AD) is a chronic, neurodegenerative disorder that affects the central nervous system and is found predominantly in elderly populations. As amyloid b protein (Ab) is one of the key players responsible for the pathogenesis of AD, we sought to investigate the protective effects of fisetin in an Ab1-42-induced rat model of AD. In this model, the protective effects of fisetin on learning and memory impairment induced by Ab1-42 were determined via the Morris water maze and passive avoidance test. Furthermore, the antioxidant activity, anti-inflammation, and apoptosis effect of fisetin were investigated using biochemical and immunohistochemical methods. The results showed that intragastric (i.g.) administration of fisetin (100, 50, and 25 mg/kg) improved previous learning and memory impairments in Ab1-42-treated rats. Hippocampal tissue from these fisetin-treated rats revealed that the activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) were markedly enhanced, and that the levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were significantly reduced. Meanwhile, fisetin also significantly attenuated Ab1-42-induced cholinergic dysfunction such as elevated the activity of choline acetyltransferase (ChAT) and reduced the activity of acetylcholine esterase (AChE). In addition, hippocampal tissue obtained from fisetin-treated rats revealed a reversal of Ab1-42-induced effects on apoptotic pathway protein (caspase-3) expression and inflammatory response of glial fibrillary acidic protein (GFAP). This indicated that the amount of degenerating hippocampal neurons with apoptotic features was dramatically reduced after treatment with fisetin. Collectively, these findings suggest that fisetin has potential as a treatment agent for Alzheimer's disease and that its effects occur through several mechanisms, including inhibition of oxidative stress, adjustments to previous cholinergic dysfunction, anti-inflammatory actions, and decreased apoptotic activity.

3,6'-Disinapoylsucrose alleviates the amyloid precursor protein and lipopolysaccharide induced cognitive dysfunction through upregulation of the TrkB/BDNF pathway.

The aim of this study is to explore the effect and mechanism of 3,6'-disinapoylsucrose (DISS) on an Alzheimer's disease (AD) mice model induced by APPswe695 lentivirus (LV) and intraperitoneal injection of lipopolysaccharide (LPS). The results show that DISS improves cognitive ability, decreases the levels of IL-2, IL-6, IL-1ß, and TNF-α, reduces the expression of NF-κB p65, and alleviates Aß deposition and nerve cell damage. DISS can regulate tyrosine kinase B (TrkB)/brain-derived neurotrophic factor (BDNF) signaling in the hippocampus. In summary, DISS can significantly alleviate neuroinflammation, spatial learning and memory disorders in AD model mice.

Protective Effect of Chitosan Oligosaccharide against Hydrogen Peroxide-Mediated Oxidative Damage and Cell Apoptosis via Activating Nrf2/ARE Signaling Pathway.

Chitosan oligosaccharide (COS), hydrolyzed and deacetylated from chitosan, has been reported to possess varieties of biological activities. Alzheimer's disease (AD) is a multifactorial progressive neurodegenerative disorder characterized by cognitive decline and memory loss, where oxidative stress was reported to be an overwhelming cause of the occurrence of AD. We have previously reported that COS could significantly decrease cell death, ROS generation, and lipid peroxidation, though the potential mechanism was yet to be determined. This study was designed to investigate the neuroprotective effect of COS against hydrogen peroxide (H2O2)-induced oxidative stress and apoptosis in neuronal SH-SY5Y cells. Our results indicated that COS could dose-dependently scavenge H2O2 in the cell-free systems. Accordingly, COS markedly decreased H2O2-induced cell apoptosis and intracellular ROS generation, while increased antioxidant capacity in SH-SY5Y cells. Further, COS significantly reduced the expression of Bax and upregulated Bcl-2. The mRNA and protein expression levels of nuclear Nrf2, heme oxygenase 1 (HO-1), and NAD(P)H: quinone oxidoreductase 1 (NQO1) were significantly increased upon COS treatment. Moreover, Nrf2-siRNA evidently reversed the promotive effect of COS on expression levels of HO-1 and NQO1, and ARE-driven transcriptional activity as determined by double-luciferase reporter gene assay. Besides, COS reversed H2O2-mediated increased phosphorylation of ERK1/2 and p38 MAPK. In conclusion, our findings indicate that COS could protect SH-SY5Y cells from oxidative damage and apoptosis via regulating Nrf2/ARE signaling pathway, which may provide new applications for the prevention and treatment of AD.

Rapid Identification of 3,6'-Disinapoyl Sucrose Metabolites in Alzheimer's Disease Model Mice Using UHPLC-Orbitrap Mass Spectrometry.

Alzheimer's disease (AD) is a degenerative disease of the central nervous system characterized by the progressive impairment of neural activity. Studies have shown that 3,6'-disinapoyl sucrose (DISS) can alleviate the pathological symptoms of AD through the activation of the cAMP/CREB/BDNF signaling pathway. However, the exact biochemical mechanisms of action of DISS are not clear. This study explores metabolism of DISS in an AD mouse model, induced by the microinjection of a lentiviral expression plasmid of the APPswe695 gene into CA1 of the hippocampus. After gavage administration of DISS (200 mg/kg), the kidneys, livers, brains, plasma, urine, and feces were collected for UHPLC-Orbitrap mass spectrometry analysis. Twenty metabolites, including the prototype drug of DISS, were positively or tentatively identified based on accurate mass measurements, characteristic fragmentation behaviors, and retention times. Thus, the metabolic pathways of DISS in AD mice were preliminarily elucidated through the identification of metabolites, such as ester bond cleavage, demethoxylation, demethylation, and sinapic acid-related products. Furthermore, differences in the in vivo distribution of several metabolites were observed between the model and sham control groups. These findings can provide a valuable reference for the pharmacological mechanisms and biosafety of DISS.

Rescue of cognitive deficits in APP/PS1 mice by accelerating the aggregation of ß-amyloid peptide.

BACKGROUND: Brain amyloid deposition is one of the main pathological characteristics of Alzheimer's disease (AD). Soluble oligomers formed during the process that causes ß-amyloid (Aß) to aggregate into plaques are considered to have major neurotoxicity. Currently, drug development for the treatment of Alzheimer's disease has encountered serious difficulties. Our newly proposed solution is to accelerate the aggregation of Aß to reduce the amount of cytotoxic Aß oligomers in brain tissue. This strategy differs from the existing strategy of reducing the total Aß content and the number of amyloid plaques. METHOD: In this study, we screened a small library and found that a flavonoid compound (ZGM1) promoted the aggregation of ß-amyloid (Aß). We further verified the binding of ZGM1 to Aß42 using a microscale thermophoresis (MST) assay. Subsequently, we used dot blotting (DB), transmission electron microscopy (TEM), and thioflavin T fluorescence (ThT) measurements to study the aggregation of Aß under the influence of ZGM1. By using cell experiments, we determined whether ZGM1 can inhibit the cytotoxicity of Aß. Finally, we studied the protective effects of ZGM1 on cognitive function in APPswe/PS1 mice via behavioral experiments and measured the number of plaques in the mouse brain by thioflavin staining. RESULTS: ZGM1 can bind with Aß directly and mediate a new Aß assembly process to form reticular aggregates and reduce the amount of Aß oligomers. Animal experiments showed that ZGM1 can significantly improve cognitive dysfunction and that Aß plaque deposition in the brain tissue of mice in the drug-administered group was significantly increased. CONCLUSION: Our research suggests that promoting Aß aggregation is a promising treatment method for AD and deserves further investigation.

Rapid Identification of Tanshinone IIA Metabolites in an Amyloid-ß1-42 Induced Alzherimer's Disease Rat Model using UHPLC-Q-Exactive Qrbitrap Mass Spectrometry.

Alzheimer's disease (AD) is a neurodegenerative disorder that damages health and welfare of the elderly, and there has been no effective therapy for AD until now. It has been proved that tanshinone IIA (tan IIA) could alleviate pathological symptoms of AD via improving non-amyloidogenic cleavage of amyloid precursor protein, decreasing the accumulations of p-tau and amyloid-ß1-42 (Aß1-42), and so forth. However, the further biochemical mechanisms of tan IIA are not clear. The experiment was undertaken to explore metabolites of tan IIA in AD rats induced by microinjecting Aß1-42 in the CA1 region of hippocampus. AD rats were orally administrated with tan IIA at 100 mg/kg weight, and plasma, urine, faeces, kidney, liver and brain were then collected for metabolites analysis by UHPLC-Q-Exactive Qrbitrap mass spectrometry. Consequently, a total of 37 metabolites were positively or putatively identified on the basis of mass fragmentation behavior, accurate mass measurements and retention times. As a result, methylation, hydroxylation, dehydration, decarbonylation, reduction reaction, glucuronidation, glycine linking and their composite reactions were characterized to illuminate metabolic pathways of tan IIA in vivo. Several metabolites presented differences in the distribution of tan IIA between the sham control and the AD model group. Overall, these results provided valuable references for research on metabolites of tan IIA in vivo and its probable active structure for exerting neuroprotection.

A Review of the Preparation, Analysis and Biological Functions of Chitooligosaccharide.

Chitooligosaccharide (COS), which is acknowledged for possessing multiple functions, is a kind of low-molecular-weight polymer prepared by degrading chitosan via enzymatic, chemical methods, etc. COS has comprehensive applications in various fields including food, agriculture, pharmacy, clinical therapy, and environmental industries. Besides having excellent properties such as biodegradability, biocompatibility, adsorptive abilities and non-toxicity like chitin and chitosan, COS has better solubility. In addition, COS has strong biological functions including anti-inflammatory, antitumor, immunomodulatory, neuroprotective effects, etc. The present paper has summarized the preparation methods, analytical techniques and biological functions to provide an overall understanding of the application of COS.

The inhibitory effect of chitosan oligosaccharides on ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) in HEK293 APPswe cells.

Amyloid precursor protein (APP) proteolysis is essential for the production of ß-amyloid peptides (Aß) that form senile plaques in Alzheimer's disease (AD) brains. The ß-site amyloid protein precursor cleaving enzyme 1 (BACE1) is the rate limiting enzyme in the generation of Aß from APP, inhibition of BACE1 is thereby considered as an attractive strategy for anti-AD drug discovery. Chitosan oligosaccharides (COS) has been shown to possess various biological activities. Here we investigated the potential inhibitory effect of COS on both BACE1 expression in HEK293 APPswe cells and BACE1 enzymatic activity in vitro. The results showed that COS (100-500µg/ml) dose-dependently decreased the cell apoptosis, and potently repressed the secretion of both Aß40 and Aß42 as determined by ELISA. Moreover, treatment with COS resulted in a dramatic reduction in BACE1 mRNA and protein expression level, eIF2α phosphorylation as well as BACE1 enzymatic activity. Taken together, our findings indicate that COS can ameliorate Aß-associated neurotoxicity, which may be, at least in part, attributable to reductions in BACE1 enzymatic activity and expression.

Neuroprotective effects of liquiritin on cognitive deficits induced by soluble amyloid-ß1-42 oligomers injected into the hippocampus.

This study assessed the modulating effects of liquiritin against cognitive deficits, oxidative damage, and neuronal apoptosis induced by subsequent bilateral intrahippocampal injections of aggregated amyloid-ß1-42 (Aß1-42). This study also explored the molecular mechanisms underlying the above phenomena. Liquiritin was orally administered to rats with Aß1-42-induced cognitive deficits for 2 weeks. The protective effects of liquiritin on the learning and memory impairment induced by Aß1-42 were examined in vivo by using Morris water maze. The rats were then euthanized for further studies. The antioxidant activities of liquiritin in the hippocampus of the rats were investigated by biochemical and immunohistochemical methods. The apoptosis of the neurons was assessed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay. Liquiritin at doses of 50-100 mg/kg significantly improved the cognitive ability, restored the abnormal activities of glutathione peroxidase and superoxide dismutase, and decreased the levels of malondialdehyde，8-hydroxy-2'-deoxyguanosine and protein carbonyl in the hippocampus of rats with Alzheimer's disease. Moreover, neural apoptosis in the hippocampus of Aß1-42-treated rats was reversed by liquiritin. Liquiritin can significantly ameliorate Aß1-42-induced spatial learning and memory impairment by inhibiting oxidative stress and neural apoptosis.

Roles of O-GlcNAcylation on amyloid-ß precursor protein processing, tau phosphorylation, and hippocampal synapses dysfunction in Alzheimer's disease.

Alzheimer disease (AD), a central nervous system degenerative disease, is characterized by abnormal deposition of amyloid-ß peptide (Aß), neurofibrillary tangles formed by hyperphosphorylated tau and synaptic loss. It is widely accepted that Aß is the chief culprit of AD. Aß peptide is the cleavage product of amyloid-ß precursor protein (APP). Recently, more attention has been paid to O-linked ß-N-acetylglucosaminylation (O-GlcNAcylation) modification of protein. O-GlcNAcylation plays a significant role in hippocampal synaptic function. Abated O-GlcNAcylation might be a modulator in progression of AD through regulating activity of pertinent enzymes and factors. Evidence suggests that enhanced O-GlcNAcylation interacts with tau phosphorylation and prevents brain from tau and Aß-induced impairment. Here, we review the roles of O-GlcNAcylation in APP cleavage, tau phosphorylation and hippocampal synapses function.

Chitosan oligosaccharides alleviate cognitive deficits in an amyloid-ß1-42-induced rat model of Alzheimer's disease.

AIM: The objective of the present study was two-fold: (i) to evaluate the modulating effects of chitosan oligosaccharides (COS) on cognitive deficits and (ii) to explore their underlying molecular mechanisms. METHODS: The Morris water maze and passive avoidance tests were used to determine the neuroprotective effects of COS on Aß1-42-induced learning and memory impairments. Biochemical methods were then used to assess COS antioxidant activity in hippocampus, including effects on apoptosis (TUNEL assay) and changes in inflammatory mediators (immunohistochemistry). RESULTS: Orally administered COS at 200, 400, or 800 mg/kg doses were effective at reducing the learning and memory deficits in Aß1-42-induced rats. These same doses were also able to ameliorate neuronal apoptosis. The neuroprotective effects of COS were closely associated with its ability to inhibit oxidative stress. This was shown with decreasing levels of malondialdehyde, 8-hydroxy-2'-deoxyguanosine and increasing levels of glutathione peroxidase and super oxide dismutase activities. COS were also shown to suppress the inflammatory response and decrease measures of inflammation via a decrease in the release of proinflammatory cytokines (e.g. interleukin-1beta and tumor necrosis factor-alpha). CONCLUSION: Taken together, our findings suggest that COS have beneficial effects on the cognitive impairments seen in an Aß1-42-induced model of Alzheimer's disease via inhibiting oxidative stress and neuroinflammatory responses.

Chitosan Oligosaccharides Inhibit/Disaggregate Fibrils and Attenuate Amyloid ß-Mediated Neurotoxicity.

Alzheimer's disease (AD) is characterized by a large number of amyloid-ß (Aß) deposits in the brain. Therefore, inhibiting Aß aggregation or destabilizing preformed aggregates could be a promising therapeutic target for halting/slowing the progression of AD. Chitosan oligosaccharides (COS) have previously been reported to exhibit antioxidant and neuroprotective effects. Recent study shows that COS could markedly decrease oligomeric Aß-induced neurotoxicity and oxidative stress in rat hippocampal neurons. However, the potential mechanism that COS reduce Aß-mediated neurotoxicity remains unclear. In the present study, our findings from circular dichroism spectroscopy, transmission electron microscope and thioflavin T fluorescence assay suggested that COS act as an inhibitor of Aß aggregation and this effect shows dose-dependency. Moreover, data from thioflavin T assay indicated that COS could significantly inhibit fibrils formation and disrupt preformed fibrils in a dose-dependent manner. Furthermore, the addition of COS attenuated Aß1-42-induced neurotoxicity in rat cortical neurons. Taken together, our results demonstrated for the first time that COS could inhibit Aß1-42 fibrils formation and disaggregate preformed fibrils, suggesting that COS may have anti-Aß fibrillogenesis and fibril-destabilizing properties. These findings highlight the potential role of COS as novel therapeutic agents for the prevention and treatment of AD.

Treatment with lutein provides neuroprotection in mice subjected to transient cerebral ischemia.

Lutein is known to be a nonprovitamin A carotenoid found in broccoli and spinach. The aim of present study was to investigate whether lutein can protect brain against ischemic injury by reducing oxidative stress. Male ICR mice were randomly divided into five experimental groups: model group, sham group, lutein high, middle, and low-dose groups (30, 15, and 7.5 mg/kg). Mice were subjected to a 2-h middle cerebral artery occlusion followed by reperfusion for 22 h. The reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, antioxidant enzyme activities, malondialdehyde (MDA), and the carbonyl content in oxidatively modified proteins in brain tissue were determined with colorimetric method. The 8-hydroxy deoxyguanosine (8-OHdG) expression was measured by immunohistochemistry assay, and the neuron apoptosis was detected by TdT-mediated dUTP nick end labeling assay. Then, the neurological deficit scores were measured at last. Treatment of lutein significantly elevated the ratio of GSH/GSSG as well as activities of superoxide dismutase, glutathione peroxidase, and catalase and obviously decreased the contents of MDA, brain carbonyl, the expression of 8-OHdG, the number of apoptotic cells, and neurological deficit scores. Our results demonstrate that administration of lutein affords strong neuroprotective effect against transient cerebral ischemic injury and that the effect might be associated with its antioxidant property.

Development of loop-mediated isothermal amplification assay for specific and rapid detection of differential goat pox virus and sheep pox virus.

BACKGROUND: Capripox viruses are economically important pathogens in goat and sheep producing areas of the world, with specific focus on goat pox virus (GTPV), sheep pox virus (SPPV) and the Lumpy Skin Disease virus (LSDV). Clinically, sheep pox and goat pox have the same symptoms and cannot be distinguished serologically. This presents a real need for a rapid, inexpensive, and easy to operate and maintain genotyping tool to facilitate accurate disease diagnosis and surveillance for better management of Capripox outbreaks. RESULTS: A LAMP method was developed for the specific differential detection of GTPV and SPPV using three sets of LAMP primers designed on the basis of ITR sequences. Reactions were performed at 62°C for either 45 or 60 min, and specificity confirmed by successful differential detection of several GTPV and SPPV isolates. No cross reactivity with Orf virus, foot-and-mouth disease virus (FMDV), A. marginale Lushi isolate, Mycoplasma mycoides subsp. capri, Chlamydophila psittaci, Theileria ovis, T. luwenshuni, T. uilenbergi or Babesia sp was noted. RFLP-PCR analysis of 135 preserved epidemic materials revealed 48 samples infected with goat pox and 87 infected with sheep pox, with LAMP test results showing a positive detection for all samples. When utilizing GTPV and SPPV genomic DNA, the universal LAMP primers (GSPV) and GTPV LAMP primers displayed a 100% detection rate; while the SPPV LAMP detection rate was 98.8%, consistent with the laboratory tested results. CONCLUSIONS: In summary, the three sets of LAMP primers when combined provide an analytically robust method able to fully distinguish between GTPV and SPPV. The presented LAMP method provides a specific, sensitive and rapid diagnostic tool for the distinction of GTPV and SPPV infections, with the potential to be standardized as a detection method for Capripox viruses in endemic areas.

Chitosan oligosaccharides protect rat primary hippocampal neurons from oligomeric ß-amyloid 1-42-induced neurotoxicity.

ß-Amyloid peptide (Aß), the major component of senile plaques in patients with Alzheimer's disease (AD), is believed to facilitate the progressive neurodegeneration that occurs in this disease. Mounting natural compounds are proved to be potential candidates for the prevention and treatment of AD. Chitosan oligosaccharides (COSs), the enzymatic hydrolysates of chitosan, have been reported to possess diverse biological activities. Here we investigated the effect of COSs on oligomeric Aß-mediated toxicity in rat primary hippocampal neurons. Pretreatment with COSs markedly inhibited cell death induced by Aß exposure as determined by cell viability assay and lactate dehydrogenase release assay. In parallel, the generation of reactive oxygen species and lipid peroxidation were attenuated by COSs. Furthermore, our results indicated that COSs remarkably prevented Aß-induced cell apoptosis as manifested by depressing the elevation of Bax/Bcl-2 ratio and caspase-3 activation, suggesting that the neuroprotective effect of COSs could be partially due to apoptosis regulation. In addition, pretreatment with COSs significantly blocked Aß-induced phosphorylation of c-Jun N-terminal kinase. Taken together, these findings may shed light on the role of COSs as a potential therapeutic agent for AD.

The mitochondrial genome of Paramphistomum cervi (Digenea), the first representative for the family Paramphistomidae.

We determined the complete mitochondrial DNA (mtDNA) sequence of a fluke, Paramphistomum cervi (Digenea: Paramphistomidae). This genome (14,014 bp) is slightly larger than that of Clonorchis sinensis (13,875 bp), but smaller than those of other digenean species. The mt genome of P. cervi contains 12 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 2 non-coding regions (NCRs), a complement consistent with those of other digeneans. The arrangement of protein-coding and ribosomal RNA genes in the P. cervi mitochondrial genome is identical to that of other digeneans except for a group of Schistosoma species that exhibit a derived arrangement. The positions of some transfer RNA genes differ. Bayesian phylogenetic analyses, based on concatenated nucleotide sequences and amino-acid sequences of the 12 protein-coding genes, placed P. cervi within the Order Plagiorchiida, but relationships depicted within that order were not quite as expected from previous studies. The complete mtDNA sequence of P. cervi provides important genetic markers for diagnostics, ecological and evolutionary studies of digeneans.

Aß-40 Y10F increases ßfibrils formation but attenuates the neurotoxicity of amyloid-ß peptide.

Alzheimer's disease (AD) is characterized by the abnormal aggregation of amyloid-ß peptide (Aß) in extracellular deposits known as senile plaques. The tyrosine residue (Tyr-10) is believed to be important in Aß-induced neurotoxicity due to the formation of tyrosyl radicals. To reduce the likelihood of cross-linking, here we designed an Aß-40 analogue (Aß-40 Y10F) in which the tyrosine residue was substituted by a structurally similar residue, phenylalanine. The aggregation rate was determined by the Thioflavin T (ThT) assay, in which Aß-40 Y10F populated an ensemble of folded conformations much quicker and stronger than the wild type Aß. Biophysical tests subsequently confirmed the results of the ThT assay, suggesting the measured increase of ß-aggregation may arise predominantly from enhancement of hydrophobicity upon substitution and thus the propensity of intrinsic ß-sheet formation. Nevertheless, Aß-40 Y10F exhibited remarkably decreased neurotoxicity compared to Aß-40 which could be partly due to the reduced generation of hydrogen peroxide. These findings may lead to further understanding of the structural perturbation of Aß to its fibrillation.

Protective effects of curcumin on amyloid-ß-induced neuronal oxidative damage.

To investigate the protective effects of curcumin against amyloid-ß (Aß)-induced neuronal damage. Primary rat cortical neurons were cultured with different treatments of Aß and curcumin. Neuronal morphologies, viability and damage were assessed. Neuronal oxidative stress was assessed, including extracellular hydrogen peroxide and intracellular reactive oxygen species. The abilities of curcumin to scavenge free radicals and to inhibit Aß aggregation and ß-sheeted formation are further assessed and discussed. Curcumin preserves cell viability, which is decreased by Aß. The results of changed morphology, released Lactate dehydrogenases and cell viability assays indicate that curcumin protects Aß-induced neuronal damage. Curcumin depresses Aß-induced up-regulation of neuronal oxidative stress. The treatment sequence impacts the protective effect of curcumin on Aß-induced neuronal damage. Curcumin shows a more protective effect on neuronal oxidative damage when curcumin was added into cultured neurons not later than Aß, especially prior to Aß. The abilities of curcumin to scavenge free radicals and to inhibit the formation of ß-sheeted aggregation are both beneficial to depress Aß-induced oxidative damage. Curcumin prevents neurons from Aß-induced oxidative damage, implying the therapeutic usage for the treatment of Alzheimer's disease patients.