curcumin and Paralysis

This study aims to investigate the blood-brain barrier (BBB) permeability of curcumin analogues with shortened linkers and their ability to protect against amyloid-beta toxicity in a whole organism model.. Four curcumin analogues were synthesized. These analogues and curcumin were evaluated for their BBB permeability in the parallel artificial membrane permeability assay. The transgenic Caenorhabditis elegansGMC101 that expresses human Aβ. The four analogues showed improved BBB permeability vs curcumin in the PAMPA with the hemi-analogue C4 having the highest permeability coefficient. At 100 μm, analogues C1 and C4 as well as curcumin significantly prolonged the survival of the nematodes protecting against Aβ toxicity. However, only curcumin and C4 showed protection at lower concentrations. skn-1mRNA was significantly elevated in nematodes treated with curcumin and C4 indicating SKN-1/Nrf activation as a possible mode of action.. Analogue C4 provides a new lead for the development of a curcumin-based compound for protection against Aβ toxicity with an improved BBB permeability.

Topics: Amyloid beta-Peptides; Animals; Blood-Brain Barrier; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Curcumin; Disease Models, Animal; DNA-Binding Proteins; Paralysis; Permeability; Phytochemicals; Protective Agents; Transcription Factors

Botulinum neurotoxins consist of a metalloprotease linked via a conserved interchain disulfide bond to a heavy chain responsible for neurospecific binding and translocation of the enzymatic domain in the nerve terminal cytosol. The metalloprotease activity is enabled upon disulfide reduction and causes neuroparalysis by cleaving the SNARE proteins. Here, we show that the thioredoxin reductase-thioredoxin protein disulfide-reducing system is present on synaptic vesicles and that it is functional and responsible for the reduction of the interchain disulfide of botulinum neurotoxin serotypes A, C, and E. Specific inhibitors of thioredoxin reductase or thioredoxin prevent intoxication of cultured neurons in a dose-dependent manner and are also very effective inhibitors of the paralysis of the neuromuscular junction. We found that this group of inhibitors of botulinum neurotoxins is very effective in vivo. Most of them are nontoxic and are good candidates as preventive and therapeutic drugs for human botulism.

Topics: Animals; Botulinum Toxins; Cerebral Cortex; Curcumin; Cytoplasm; Disulfides; Enzyme Activation; Enzyme Inhibitors; Imidazoles; Male; Mice; Neurons; Paralysis; Serotyping; Synaptic Vesicles; Synaptosomal-Associated Protein 25; Thioredoxin-Disulfide Reductase; Thioredoxins

Genetic studies indicate that protein homeostasis is a major contributor to metazoan longevity. Collapse of protein homeostasis results in protein misfolding cascades and the accumulation of insoluble protein fibrils and aggregates, such as amyloids. A group of small molecules, traditionally used in histopathology to stain amyloid in tissues, bind protein fibrils and slow aggregation in vitro and in cell culture. We proposed that treating animals with such compounds would promote protein homeostasis in vivo and increase longevity. Here we show that exposure of adult Caenorhabditis elegans to the amyloid-binding dye Thioflavin T (ThT) resulted in a profoundly extended lifespan and slowed ageing. ThT also suppressed pathological features of mutant metastable proteins and human β-amyloid-associated toxicity. These beneficial effects of ThT depend on the protein homeostasis network regulator heat shock factor 1 (HSF-1), the stress resistance and longevity transcription factor SKN-1, molecular chaperones, autophagy and proteosomal functions. Our results demonstrate that pharmacological maintenance of the protein homeostatic network has a profound impact on ageing rates, prompting the development of novel therapeutic interventions against ageing and age-related diseases.

Topics: Aging; Amyloid; Amyloid beta-Peptides; Animals; Autophagy; Benzothiazoles; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Curcumin; DNA-Binding Proteins; Dose-Response Relationship, Drug; Forkhead Transcription Factors; Homeostasis; Humans; Longevity; Molecular Chaperones; Paralysis; Phenotype; Proteasome Endopeptidase Complex; Protein Binding; Proteins; Survival Analysis; Thiazoles; Transcription Factors

Familial forms of amyotrophic lateral sclerosis (ALS) can be caused by mutations in copper, zinc-superoxide dismutase (SOD1). Mice expressing SOD1 mutants demonstrate a robust neuroinflammatory reaction characterized, in part, by up-regulation of tumor necrosis factor alpha (TNFalpha) and its primary receptor TNF-RI. In an effort to identify small molecule inhibitors of neuroinflammation useful in treatment of ALS, a microglial culture system was established to identify TNFalpha antagonists. Walker EOC-20 microglia cells were stimulated with recombinant TNFalpha, with or without inhibitors, and the cell response was indexed by NO2- output. Three hundred and fifty-five rationally selected compounds were included in this bioassay. The arachidonic acid 5-lipoxygenase (5LOX) and tyrosine kinase inhibitor nordihydroguaiaretic acid (NDGA), a natural dicatechol, was one of the most potent non-cytotoxic antagonists tested (IC50 8 +/- 3 microm). Investigation of the G93A-SOD1 mouse model for ALS revealed increased message and protein levels of 5LOX at 120 days of age. Oral NDGA (2500 p.p.m.) significantly extended lifespan and slowed motor dysfunction in this mouse, when administration was begun relatively late in life (90 days). NDGA extended median total lifespan of G93A-SOD1 mice by 10%, and life expectancy following start of treatment was extended by 32%. Disease-associated gliosis and cleaved microtubule-associated tau protein, an indicator of axon damage, were likewise reduced by NDGA. Thus, TNFalpha antagonists and especially 5LOX inhibitors might offer new opportunities for treatment of ALS.

Topics: Administration, Oral; Age Factors; Animals; Behavior, Animal; Blotting, Northern; Blotting, Western; Body Mass Index; Cell Line; Curcumin; Dose-Response Relationship, Drug; Drug Interactions; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Inhibitory Concentration 50; Lipoxygenase Inhibitors; Masoprocol; Mice; Mice, Transgenic; Microglia; Models, Neurological; Motor Activity; Nitric Oxide; Paralysis; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Rotarod Performance Test; Spinal Cord; Statistics, Nonparametric; Superoxide Dismutase; Survival; tau Proteins; Tumor Necrosis Factor-alpha