Self-Assembly Driven Formation of Functional Ultralong "Artificial Fibers" to Mitigate the Neuronal Damage Associated with Alzheimer's Disease.

Fibrillation of amyloid beta (Aß) is the key event in the amyloid neurotoxicity process that induces a chain of toxic events including oxidative stress, caspase activation, poly(ADP-ribose) polymerase cleavage, and mitochondrial dysfunction resulting in neuronal loss and memory decline manifesting as clinical dementia in humans. Herein, we report the development of a novel, biologically active supramolecular probe, INHQ, and achieve functional nanoarchitectures via a self-assembly process such that ultralong fibers are achieved spontaneously. With specifically decorated functional groups on INHQ such as imidazole, hydroxyquinoline, hydrophobic chain, and hydroxyquinoline molecules, these ultralong fibers coassembled efficiently with toxic Aß oligomers and mitigated the amyloid-induced neurotoxicity by blocking the aforementioned biochemical events leading to neuronal damage in mice. These functional ultralong "Artificial Fibers" morphologically resemble the amyloid fibers and provide a higher surface area of interaction that improves its clearance ability against the Aß aggregates. The efficacy of this novel INHQ molecule was ascertained by its high ability to interact with Aß. Moreover, this injectable, ultralong INHQ functional "artificial fiber" translocates through the blood-brain barrier and successfully attenuates the amyloid-triggered neuronal damage and pyknosis in the cerebral cortex of wild-type mouse. Utilizing various spectroscopic techniques, morphology analysis, and in vitro, in silico, and in vivo studies, these ultralong INHQ fibers are proven to hold great promise for treating neurological disorders at all stages with a potential to replace the existing medications, reduce complications in the brain, and eradicate the amyloid-triggered neurotoxicity implicated in numerous disorders in human through a rare synergistic mechanism.

The Neuroprotective Activities of the Novel Multi-Target Iron-Chelators in Models of Alzheimer's Disease, Amyotrophic Lateral Sclerosis and Aging.

The concept of chelation therapy as a valuable therapeutic approach in neurological disorders led us to develop multi-target, non-toxic, lipophilic, brain-permeable compounds with iron chelation and anti-apoptotic properties for neurodegenerative diseases, such as Parkinson's disease (PD), Alzheimer's disease (AD), age-related dementia and amyotrophic lateral sclerosis (ALS). Herein, we reviewed our two most effective such compounds, M30 and HLA20, based on a multimodal drug design paradigm. The compounds have been tested for their mechanisms of action using animal and cellular models such as APP/PS1 AD transgenic (Tg) mice, G93A-SOD1 mutant ALS Tg mice, C57BL/6 mice, Neuroblastoma × Spinal Cord-34 (NSC-34) hybrid cells, a battery of behavior tests, and various immunohistochemical and biochemical techniques. These novel iron chelators exhibit neuroprotective activities by attenuating relevant neurodegenerative pathology, promoting positive behavior changes, and up-regulating neuroprotective signaling pathways. Taken together, these results suggest that our multifunctional iron-chelating compounds can upregulate several neuroprotective-adaptive mechanisms and pro-survival signaling pathways in the brain and might function as ideal drugs for neurodegenerative disorders, such as PD, AD, ALS, and aging-related cognitive decline, in which oxidative stress and iron-mediated toxicity and dysregulation of iron homeostasis have been implicated.

8-Geranyloxycarbostyril as a potent 15-LOX-1 inhibitor showed great anti-tumor effects against prostate cancer.

Carbostyrils are quinolone derivatives, with possible growth inhibition properties on cancer cells. Unlike many tumors, 15-Lipoxygenase-1 (15-LOX-1) is highly expressed in prostate cancer (PCa) cells and has oncogenic properties. Here, with the hypothesis that 6-, 7- and 8-geranyloxycarbostyril (GQ) have inhibitory properties on 15-LOX-1, their effects were assessed on PCa cells. Their cytotoxic effects were evaluated by MTT assay and mechanism of cell death was investigated using annexin V/PI staining. Finally, the anti-tumor properties of 8-GQ were assessed in immunocompromised C57BL/6 mice bearing human PCa cells. Accordingly, these compounds could effectively inhibit 15-LOX activity in PCa cells. MTT and flow cytometry tests confirmed their toxic effects on PCa cells, with no significant toxicity on normal cells, and apoptosis was the main mechanism of cell death. In vivo results indicated that use of 8-GQ at 50 mg/kg had stronger anti-tumor effects than 5 mg/kg cisplatin, with fewer side effects on normal tissues. Therefore, 8-GQ can be introduced as a potential drug candidate with 15-LOX-1 inhibitory potency, which can be effective in treatment of prostate cancer, and should be considered for further drug screening investigations.

An Overview of Several Inhibitors for Alzheimer's Disease: Characterization and Failure.

Amyloid beta (Aß) oligomers are the most neurotoxic aggregates causing neuronal death and cognitive damage. A detailed elucidation of the aggregation pathways from oligomers to fibril formation is crucial to develop therapeutic strategies for Alzheimer's disease (AD). Although experimental techniques rely on the measure of time- and space-average properties, they face severe difficulties in the investigation of Aß peptide aggregation due to their intrinsically disorder character. Computer simulation is a tool that allows tracing the molecular motion of molecules; hence it complements Aß experiments, as it allows to explore the binding mechanism between metal ions and Aß oligomers close to the cellular membrane at the atomic resolution. In this context, integrated studies of experiments and computer simulations can assist in mapping the complete pathways of aggregation and toxicity of Aß peptides. Aß oligomers are disordered proteins, and due to a rapid exploration of their intrinsic conformational space in real-time, they are challenging therapeutic targets. Therefore, no good drug candidate could have been identified for clinical use. Our previous investigations identified two small molecules, M30 (2-Octahydroisoquinolin-2(1H)-ylethanamine) and Gabapentin, capable of Aß binding and inhibiting molecular aggregation, synaptotoxicity, intracellular calcium signaling, cellular toxicity and memory losses induced by Aß. Thus, we recommend these molecules as novel candidates to assist anti-AD drug discovery in the near future. This review discusses the most recent research investigations about the Aß dynamics in water, close contact with cell membranes, and several therapeutic strategies to remove plaque formation.

7-[[(4-methyl-2-pyridinyl)amino](2-pyridinyl)methyl]-8-quinolinol (compound 30666) inhibits enhancer activity and reduces B-cell lymphoma growth - A question of specificity.

B-cell non-Hodgkin lymphoma (NHL) is among the ten most common malignancies. Survival rates range from very poor to over 90% and highly depend on the stage and subtype. Characteristic features of NHL are recurrent translocations juxtaposing an oncogene (e.g. MYC, BCL2) to the enhancers in the immunoglobulin heavy chain (IGH) locus. Survival and proliferation of many B-cell lymphomas depend on the expression of the translocated oncogene. Thus, targeting IGH enhancers as an anti-lymphoma treatment seems a promising strategy. Recently, a small molecule - 7-[[(4-methyl-2-pyridinyl)amino](2-pyridinyl)methyl]-8-quinolinol (compound 30666) was identified to decrease activity of the Eµ enhancer and reduce the expression of translocated oncogenes in multiple myeloma and some NHL cell lines (Dolloff, 2019). Here, we aimed to test the effect of compound 30666 in Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) and shed light on its mechanism of action. We report that both IGH-translocation positive NHL cells as well as IGH-translocation negative B cells and non-B cell controls treated with compound 30666 exhibited consistent growth inhibition. A statistically significant increase in cell percentage in sub-G1 phase of cell cycle was observed, suggesting induction of apoptosis. Compound 30666 downregulated MYC levels in BL cell lines and altered IGH enhancer RNA expression. Moreover, a global decrease of H3K27ac and an increase of H3K4me1 was observed upon 30666 treatment, which suggests switching enhancers to a poised or primed state. Altogether, our findings indicate that 30666 inhibitor affects enhancer activity but might not be as specific for IGH enhancers as previously reported.

The Hydroxyquinoline Analogue YUM70 Inhibits GRP78 to Induce ER Stress-Mediated Apoptosis in Pancreatic Cancer.

GRP78 (glucose-regulated protein, 78 kDa) is a key regulator of endoplasmic reticulum (ER) stress signaling. Cancer cells are highly proliferative and have high demand for protein synthesis and folding, which results in significant stress on the ER. To respond to ER stress and maintain cellular homeostasis, cells activate the unfolded protein response (UPR) that promotes either survival or apoptotic death. Cancer cells utilize the UPR to promote survival and growth. In this study, we describe the discovery of a series of novel hydroxyquinoline GRP78 inhibitors. A representative analogue, YUM70, inhibited pancreatic cancer cell growth in vitro and showed in vivo efficacy in a pancreatic cancer xenograft model with no toxicity to normal tissues. YUM70 directly bound GRP78 and inactivated its function, resulting in ER stress-mediated apoptosis. A YUM70 analogue conjugated with BODIPY showed colocalization of the compound with GRP78 in the ER. Moreover, a YUM70-PROTAC (proteolysis targeting chimera) was synthesized to force degradation of GRP78 in pancreatic cancer cells. YUM70 showed a strong synergistic cytotoxicity with topotecan and vorinostat. Together, our study demonstrates that YUM70 is a novel inducer of ER stress, with preclinical efficacy as a monotherapy or in combination with topoisomerase and HDAC inhibitors in pancreatic cancer. SIGNIFICANCE: This study identifies a novel ER stress inducer that binds GRP78 and inhibits pancreatic cancer cell growth in vitro and in vivo, demonstrating its potential as a therapeutic agent for pancreatic cancer.

IOX1 activity as sepsis therapy and an antibiotic against multidrug-resistant bacteria.

Sepsis is caused by organ dysfunction initiated by an unrestrained host immune response to infection. The emergence of antibiotic-resistant bacteria has rapidly increased in the last decades and has stimulated a firm research platform to combat infections caused by antibiotic-resistant bacteria that cannot be eradicated with conventional antibiotics. Strategies like epigenetic regulators such as lysine demethylase (Kdm) has received attention as a new target. Thus, we sought to investigate the epigenetic mechanisms in sepsis pathophysiology with the aim of discovering new concepts for treatment. A transcriptome analysis of dendritic cells during their inflammatory state identified Kdm as a critical molecule in sepsis regulation. Next, 8-hydroxyquinoline-5-carboxylic acid (IOX1) ability to control endotoxemia induced by Lipopolysaccharide and bacterial sepsis was demonstrated. IOX1 has been shown to regulate endotoxemia and sepsis caused by Escherichia coli and carbapenem-resistant Acinetobacter baumannii and has also contributed to the suppression of multidrug-resistant bacterial growth through the inhibition of DNA Gyrase. These findings show that IOX1 could be a component agent against bacterial sepsis by functioning as a broad-spectrum antibiotic with dual effects.

A hepatocyte differentiation model reveals two subtypes of liver cancer with different oncofetal properties and therapeutic targets.

Clinical observation of the association between cancer aggressiveness and embryonic development stage implies the importance of developmental signals in cancer initiation and therapeutic resistance. However, the dynamic gene expression during organogenesis and the master oncofetal drivers are still unclear, which impeded the efficient elimination of poor prognostic tumors, including human hepatocellular carcinoma (HCC). In this study, human embryonic stem cells were induced to differentiate into adult hepatocytes along hepatic lineages to mimic liver development in vitro. Combining transcriptomic data from liver cancer patients with the hepatocyte differentiation model, the active genes derived from different hepatic developmental stages and the tumor tissues were selected. Bioinformatic analysis followed by experimental assays was used to validate the tumor subtype-specific oncofetal signatures and potential therapeutic values. Hierarchical clustering analysis revealed the existence of two subtypes of liver cancer with different oncofetal properties. The gene signatures and their clinical significance were further validated in an independent clinical cohort and The Cancer Genome Atlas database. Upstream activator analysis and functional screening further identified E2F1 and SMAD3 as master transcriptional regulators. Small-molecule inhibitors specifically targeting the oncofetal drivers extensively down-regulated subtype-specific developmental signaling and inhibited tumorigenicity. Liver cancer cells and primary HCC tumors with different oncofetal properties also showed selective vulnerability to their specific inhibitors. Further precise targeting of the tumor initiating steps and driving events according to subtype-specific biomarkers might eliminate tumor progression and provide novel therapeutic strategy.

Design, Synthesis, and Characterization of Novel Linomide Analogues and their Evaluation for Anticancer Activity.

BACKGROUND: According to WHO, in 2017, about 90.5 million people suffered from cancer and about 8.8 million deaths occurred due to disease. Although the chemotherapeutic agents have decreased the mortality among the cancer patients but high toxicity and non-specific targets are still major drawbacks. Many researchers have identified linomide, a 4-hydroxy-2-quinolone derivative, as a lead molecule for the development of anticancer agents. With this background, we thought of the following objective. OBJECTIVE: The objective of this research work involves the synthesis of a series of N-(2-(4- hydroxy-2-oxo-1-phenyl-1,2-dihydroquinolin-3-yl)-2-oxoethyl)-N-alkyl substituted benzene sulfonamides IVa-d (1-3) by replacing the anilide moiety at the third position of linomide with sulfamoylacyl and also N-methyl by N-phenyl functionality. To perform in silico anticancer activity by using Molegro Virtual Docker (MVD-2013, 6.0) software and in vitro anticancer activity by MTT assay. METHODS: The starting material 4-hydroxy-1-phenylquinolin-2(1H)-one was treated with N-bromosuccinamide to yield compound II. Condensation of compound II with primary amines resulted in compounds IIIa-d, which, on coupling with substituted aromatic sulfonyl chlorides yield the title compounds IVa-d (1-3). RESULTS: All the synthesized compounds were satisfactorily characterized by spectral data. The results of docking revealed that the synthesized compounds exhibited well-conserved hydrogen bonds with one or more amino acid residues in the active pocket of EGFRK tyrosine kinase domain (PDB ID: 1m17). The MolDock Score of compound IVd-1 (-115.503) was the highest amongst those tested. The in vitro anticancer activity results showed that compound IVc-1 (R= - (CH2) 2-CH3 ; R'= -H) and IV d-1 (R= -CH2-C6H5; R'= -H) were found to be most potent against K562 cell line with an IC50 of 0.451 µM/ml and 0.455 µM/ml respectively. Compound IVd-1 also showed better potency against A549 cell line with IC50 value of 0.704 µM/ml. CONCLUSION: The results of in silico and in vitro anticancer activity are in agreement with each other. Compound IV d-1 was found to be most active of the series.

Inhibition of apoptosis signal-regulating kinase by paeoniflorin attenuates neuroinflammation and ameliorates neuropathic pain.

BACKGROUND: Neuropathic pain is a serious clinical problem that needs to be solved urgently. ASK1 is an upstream protein of p38 and JNK which plays important roles in neuroinflammation during the induction and maintenance of chronic pain. Therefore, inhibition of ASK1 may be a novel therapeutic approach for neuropathic pain. Here, we aim to investigate the effects of paeoniflorin on ASK1 and neuropathic pain. METHODS: The mechanical and thermal thresholds of rats were measured using the Von Frey test. Cell signaling was assayed using western blotting and immunohistochemistry. RESULTS: Chronic constrictive injury (CCI) surgery successfully decreased the mechanical and thermal thresholds of rats and decreased the phosphorylation of ASK1 in the rat spinal cord. ASK1 inhibitor NQDI1 attenuated neuropathic pain and decreased the expression of p-p38 and p-JNK. Paeoniflorin mimicked ASK1 inhibitor NQDI1 and inhibited ASK1 phosphorylation. Paeoniflorin decreased the expression of p-p38 and p-JNK, delayed the progress of neuropathic pain, and attenuated neuropathic pain. Paeoniflorin reduced the response of astrocytes and microglia to injury, decreased the expression of IL-1ß and TNF-α, and downregulated the expression of CGRP induced by CCI. CONCLUSIONS: Paeoniflorin is an effective drug for the treatment of neuropathic pain in rats via inhibiting the phosphorylation of ASK1, suggesting it may be effective in patients with neuropathic pain.

Genetic analysis of a novel antioxidant multi-target iron chelator, M30 protecting against chemotherapy-induced alopecia in mice.

BACKGROUND: Chemotherapy-induced alopecia has been well documented as a cause of distress to patients undergoing cancer treatment. Almost all traditional chemotherapeutic agents cause severe alopecia. Despite advances in the treatment of chemotherapy-induced alopecia, there is no effective treatment for preventing chemotherapy-induced alopecia. METHODS: In the present study, we investigated the potential role of a multi-target iron chelator, M30 in protecting against cyclophosphamide-induced alopecia in C57BL/6 mice implanted with an osmotic pump. M30 enhanced hair growth and prevented cyclophosphamide-induced abnormal hair in the mice. Furthermore, we examined the gene expression profiles derived from skin biopsy specimens of normal mice, cyclophosphamide-treated mice, and cyclophosphamide treated mice with M30 supplement. RESULTS: The top genes namely Tnfrsf19, Ercc2, Lama5, Ctsl, and Per1 were identified by microarray analysis. These genes were found to be involved in the biological processes of hair cycle, hair cycle phase, hair cycle process, hair follicle development, hair follicle maturation, hair follicle morphogenesis, regulation of hair cycle. CONCLUSION: Our study demonstrates that M30 treatment is a promising therapy for cyclophosphamide-induced alopecia and suggests that the top five genes have unique preventive effects in cyclophosphamide-induced transformation.

Iron-Chelating Drugs Enhance Cone Photoreceptor Survival in a Mouse Model of Retinitis Pigmentosa.

Purpose: Retinitis pigmentosa (RP) is a group of hereditary retinal degeneration in which mutations commonly result in the initial phase of rod cell death followed by gradual cone cell death. The mechanisms by which the mutations lead to photoreceptor cell death in RP have not been clearly elucidated. There is currently no effective treatment for RP. The purpose of this work was to explore iron chelation therapy for improving cone survival and function in the rd10 mouse model of RP. Methods: Two iron-chelating drugs, 5-(4-(2-hydroxyethyl) piperazin-1-yl (methyl)-8-hydroxyquinoline (VK28) and its chimeric derivative 5-(N-methyl-N-propargyaminomethyl)-quinoline-8-oldihydrochloride (VAR10303), were injected intraperitoneally to rd10 mice every other day starting from postnatal day 14. We investigate the effects of the two compounds on cone rescue at three time points, using a combination of immunocytochemistry, RT-PCR, Western blot analysis, and a series of visual function tests. Results: VK28 and VAR10303 treatments partially rescued cones, and significantly improved visual function in rd10 mice. Moreover, we showed that the neuroprotective effects of VK28 and VAR10303 were correlated to inhibition of neuroinflammation, oxidative stress, and apoptosis. Furthermore, we demonstrated that downregulation of NF-kB and p53 is likely to be the mechanisms by which proinflammatory mediators and apoptosis are reduced in the rd10 retina, respectively. Conclusions: VK28 and VAR10303 provided partial histologic and functional rescue of cones in RD10 mice. Our study demonstrated that iron chelation therapy might represent an effective therapeutic strategy for RP patients.

A Novel Iron Chelator-Radical Scavenger Ameliorates Motor Dysfunction and Improves Life Span and Mitochondrial Biogenesis in SOD1G93A ALS Mice.

The aim of the present study was to evaluate the therapeutic effect of the novel neuroprotective multitarget brain permeable monoamine oxidase inhibitor/iron chelating-radical scavenging drug, VAR10303 (VAR), co-administered with high-calorie/energy-supplemented diet (ced) in SOD1G93A transgenic amyotrophic lateral sclerosis (ALS) mice. Administration of VAR-ced was initiated after the appearance of disease symptoms (at day 88), as this regimen is comparable with the earliest time at which drug therapy could start in ALS patients. Using this rescue protocol, we demonstrated in the current study that VAR-ced treatment provided several beneficial effects in SOD1G93A mice, including improvement in motor performance, elevation of survival time, and attenuation of iron accumulation and motoneuron loss in the spinal cord. Moreover, VAR-ced treatment attenuated neuromuscular junction denervation and exerted a significant preservation of myofibril regular morphology, associated with a reduction in the expression levels of genes related to denervation and atrophy in the gastrocnemius (GNS) muscle in SOD1G93A mice. These effects were accompanied by upregulation of mitochondrial DNA and elevated activities of complexes I and II in the GNS muscle. We have also demonstrated that VAR-ced treatment upregulated the mitochondrial biogenesis master regulator, peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α) and increased PGC-1α-targeted metabolic genes and proteins, such as, PPARγ, UCP1/3, NRF1/2, Tfam, and ERRα in GNS muscle. These results provide evidence of therapeutic potential of VAR-ced in SOD1G93A mice with underlying molecular mechanisms, further supporting the importance role of multitarget iron chelators in ALS treatment.

Antiangiogenic activity of 2-formyl-8-hydroxy-quinolinium chloride.

Tumour growth is closely related to the development of new blood vessels to supply oxygen and nutrients to cancer cells. Without the neovascular formation, tumour volumes cannot increase and undergo metastasis. Antiangiogenesis is one of the most promising approaches for antitumour therapy. The exploration of new antiangiogenic agents would be helpful in antitumour therapy. Quinoline is an aromatic nitrogen compound characterized by a double-ring structure which exhibits a benzene ring fused to pyridine at two adjacent carbon atoms. The high stability of quinoline makes it preferable in a variety of therapeutic and pharmaceutical applications, including antitumour treatment. This work is to examine the potential antiangiogenic activity of the synthetic compound 2-Formyl-8-hydroxy-quinolinium chloride. We found that 2-Formyl-8-hydroxy-quinolinium chloride could inhibit the growth of human umbilical vein endothelial cells in vitro. Using the diethylnitrosamine-induced hepatocarcinogenesis model, 2-Formyl-8-hydroxy-quinolinium chloride showed strong antiangiogenic activity. Furthermore, 2-Formyl-8-hydroxy-quinolinium chloride could inhibit the growth of large Hep3B xenografted tumour from the nude mice. We assume that 2-Formyl-8-hydroxy-quinolinium chloride could be a potential antiangiogenic and antitumour agent and it is worthwhile to further study its underlying working mechanism.

New Hydroxyquinoline-Based Derivatives as Potent Modulators of Amyloid-ß Aggregations.

Copper and zinc have been found to contribute to the burden of amyloid-ß (Aß) aggregations in neurodegenerative Alzheimer's disease (AD). Dysregulation of these metals leads to the generation of reactive oxygen species (ROS) and eventually results in oxidative damage and accumulation of the Aß peptide, which are the key elements of the disease. Aiming to pursue the discovery of new modulators for the disease, we here rationally focused on conjugating the core hydroxyquinoline of the metal-protein attenuating compound PBT2 and the N-methylanilide analogous moiety of the Aß imaging agent to build a new type of multi-target modulators of Aß aggregations. We found that the N,N-dimethylanilinyl imines 7a, 8a, and the corresponding amines 7b, 8b exerted efficient inhibition of Cu(2+) - or Zn(2+) -induced Aß aggregations and significant disassembly of metal-mediated Aß aggregated fibrils. Further, 7a and 7b also exhibited significant ROC scavenging effects compared to PBT2. The results suggested that 7a and 7b are promising lead compounds for the development of a new therapy for AD.

Computer-assisted designed "selenoxy-chinolin": a new catalytic mechanism of the GPx-like cycle and inhibition of metal-free and metal-associated Aß aggregation.

Using support from rational computer-assisted design, a novel series of hybrids (selenoxy-chinolin) designed by fusing the metal-chelating agent CQ and the antioxidant ebselen were synthesized and evaluated as multitarget-directed ligands. Most of the hybrids demonstrated significant ability to mimic GPx, which is highly consistent with the prediction results of DFT studies for the selenenyl sulfide intermediates in the computational design. Using (77)Se, (1)H and (13)C NMR spectroscopy and high-resolution mass spectroscopy (HRMS), a novel catalytic mechanism, including a new selenium quinone active species, was first demonstrated. 2D NMR studies indicated that the typical hybrid has an effective interaction with Aß. In addition, the optimal compound 12k was found to possess an excellent ability to scavenge peroxide and to inhibit self- and metal-induced Aß aggregation, and an ability to disassemble preformed self- and metal-induced Aß aggregates effectively. Furthermore, 12k was able to penetrate the central nervous system (CNS) and did not exhibit any acute toxicity in mice at doses up to 2000 mg kg(-1). Overall, we demonstrated that hybrid 12k, through rational structure-based computational design, shows a potential for development as a therapeutic agent in AD.

Unusual Cyclodextrin Derivatives as a New Avenue to Modulate Self- and Metal-Induced Aß Aggregation.

Mounting evidence suggests an important role of cyclodextrins in providing protection in neurodegenerative disorders. Metal dyshomeostasis is reported to be a pathogenic factor in neurodegeneration because it could be responsible for damage involving oxidative stress and protein aggregation. As such, metal ions represent an effective target. To improve the metal-binding ability of cyclodextrin, we synthesized three new 8-hydroxyquinoline-cyclodextrin conjugates with difunctionalized cyclodextrins. In particular, the 3-difunctionalized regioisomer represents the first example of cyclodextrin with two pendants at the secondary rim, resulting in a promising compound. The derivatives have significant antioxidant capacity and the powerful activity in inhibiting self-induced amyloid-ß aggregation seems to be led by synergistic effects of both cyclodextrin and hydroxyquinoline. Moreover, the derivatives are also able to complex metal ions and to inhibit metal-induced protein aggregation. Therefore, these compounds could have potential as therapeutic agents in diseases related to protein aggregation and metal dyshomeostasis.

Multi-target iron-chelators improve memory loss in a rat model of sporadic Alzheimer's disease.

AIM: Novel effective treatment is urgently needed for sporadic Alzheimer's disease (sAD). M30 ([5-(N-methyl-N-propargylaminomethyl)-8-hydroxyquinoline]) and HLA-20 (5-{4-propargylpiperazin-1-ylmethyl}-8-hydroxyquinoline) are brain permeable, iron chelating compounds with antioxidant activity, showing also neuroprotective activity in animal models of neurodegeneration.Weaimed to explore their therapeutic potential in non-transgenic (non-Tg) rat model of sAD developed by intracerebroventricular administration of streptozotocin (STZ-icv). MAIN METHODS: Therapeutic effects of chronic oral M30 (2 and 10 mg/kg) and HLA20 (5 and 10 mg/kg) treatment on cognitive impairment in STZ-icv rat model were explored by Morris Water Maze (MWM) and Passive Avoidance (PA) tests in neuropreventive and neurorescue paradigms. Data were analysed by Kruskal­Wallis and Mann­Whitney U test (p b 0.05). KEY FINDINGS: Five-day oral pre-treatment with M30 and HLA20 dose-dependently prevented development of spatial memory impairment (MWM probe trial-time +116%/M30; +60%/HLA20) in STZ-icv rat model (p b 0.05). Eleven-week oral treatment with M30 (3×/week), initiated 8 days after STZ-icv administration dosedependently ameliorated already developed cognitive deficits in MWM test (reduced number of mistakes 3 months after the STZ-icv treatment ­ 59%; p b 0.05) and fully restored them in PA test (+314%; p b 0.05). Chronic M30 treatment fully restored (−47%/PHF1;−65%/AT8; p b 0.05) STZ-induced hyperphosphorylation of tau protein and normalized decreased expression of insulin degrading enzyme (+37%; p b 0.05) in hippocampus. SIGNIFICANCE: The results provide first evidence of therapeutic potential of M30 and HLA20 in STZ-icv rat model of sAD with underlying molecular mechanism, further supporting the important role of multi-target ironchelators in sAD treatment.

Neuroprotective and neurorestorative activities of a novel iron chelator-brain selective monoamine oxidase-A/monoamine oxidase-B inhibitor in animal models of Parkinson's disease and aging.

Recently, we have designed and synthesized a novel multipotent, brain-permeable iron-chelating drug, VAR10303 (VAR), possessing both propargyl and monoamine oxidase (MAO) inhibitory moieties. The present study was undertaken to determine the multiple pharmacological activities of VAR in neurodegenerative preclinical models. We demonstrate that VAR affords iron chelating/iron-induced lipid-peroxidation inhibitory potency and brain selective MAO-A and MAO-B inhibitory effects, with only limited tyramine-cardiovascular potentiation of blood pressure. The results show that in 6-hydroxydopamine rat (neuroprotection) and in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse (neurorescue) Parkinson's disease models, VAR significantly attenuated the loss of striatal dopamine levels, markedly reduced dopamine turnover, and increased tyrosine-hydroxylase levels. Furthermore, chronic systemic treatment of aged rats with VAR improved cognitive behavior deficits and enhanced the expression levels of neurotrophic factors (e.g., brain-derived neurotrophic factor, glial cell-derived neurotrophic factor, and nerve growth factor), Bcl-2 family members and synaptic plasticity in the hippocampus. Our study indicates that the multitarget compound VAR exerted neuroprotective and neurorestorative effects in animal models of Parkinson's disease and aging, further suggesting that a drug that can regulate multiple brain targets could be an ideal treatment-strategy for age-associated neurodegenerative disorders.