CR 2249: a new putative memory enhancer. Behavioural studies on learning and memory in rats and mice

Anti-Alzheimer Activity of Combinations of Cocoa with Vinpocetine or Other Nutraceuticals in Rat Model: Modulation of Wnt3/β-Catenin/GSK-3β/Nrf2/HO-1 and PERK/CHOP/Bcl-2 Pathways

Alzheimer's disease (AD) is a devastating illness with limited therapeutic interventions. The aim of this study is to investigate the pathophysiological mechanisms underlying AD and explore the potential neuroprotective effects of cocoa, either alone or in combination with other nutraceuticals, in an animal model of aluminum-induced AD. Rats were divided into nine groups: control, aluminum chloride (AlCl3) alone, AlCl3 with cocoa alone, AlCl3 with vinpocetine (VIN), AlCl3 with epigallocatechin-3-gallate (EGCG), AlCl3 with coenzyme Q10 (CoQ10), AlCl3 with wheatgrass (WG), AlCl3 with vitamin (Vit) B complex, and AlCl3 with a combination of Vit C, Vit E, and selenium (Se). The animals were treated for five weeks, and we assessed behavioral, histopathological, and biochemical changes, focusing on oxidative stress, inflammation, Wnt/GSK-3β/β-catenin signaling, ER stress, autophagy, and apoptosis. AlCl3 administration induced oxidative stress, as evidenced by elevated levels of malondialdehyde (MDA) and downregulation of cellular antioxidants (Nrf2, HO-1, SOD, and TAC). AlCl3 also upregulated inflammatory biomarkers (TNF-α and IL-1β) and GSK-3β, leading to increased tau phosphorylation, decreased brain-derived neurotrophic factor (BDNF) expression, and downregulation of the Wnt/β-catenin pathway. Furthermore, AlCl3 intensified C/EBP, p-PERK, GRP-78, and CHOP, indicating sustained ER stress, and decreased Beclin-1 and anti-apoptotic B-cell lymphoma 2 (Bcl-2) expressions. These alterations contributed to the observed behavioral and histological changes in the AlCl3-induced AD model. Administration of cocoa, either alone or in combination with other nutraceuticals, particularly VIN or EGCG, demonstrated remarkable amelioration of all assessed parameters. The combination of cocoa with nutraceuticals attenuated the AD-mediated deterioration by modulating interrelated pathophysiological pathways, including inflammation, antioxidant responses, GSK-3β-Wnt/β-catenin signaling, ER stress, and apoptosis. These findings provide insights into the intricate pathogenesis of AD and highlight the neuroprotective effects of nutraceuticals through multiple signaling pathways.

Fenofibrate ameliorates olanzapine's side effects without altering its central effect: emphasis on FGF-21-adiponectin axis

The present work was designed to investigate whether fenofibrate could ameliorate olanzapine deleterious effect on insulin resistance via its effect on fibroblast growth factor-21 (FGF-21)-adiponectin axis without affecting olanzapine antipsychotic effect in postweaning socially isolated reared female rats. Treatment with olanzapine (6 mg/kg, intraperitoneally) or fenofibrate (100 mg/kg, orally) have been started 5 weeks after isolation, then behavioral tests, hippocampal content of neurotransmitters, and brain-derived neurotrophic factor (BDNF) were assessed. Moreover, insulin resistance, lipid profile, FGF-21, adiponectin, inflammatory, and oxidative stress markers of adipose tissue were assessed. Treatment of isolated-reared animals with olanzapine, or fenofibrate significantly ameliorated the behavioral and biochemical changes induced by postweaning social isolation. Co-treatment showed additive effects in improving hippocampal BDNF level. Besides, fenofibrate reduced the elevation in weight gain, adiposity index, insulin resistance, lipid profile, and FGF-21 level induced by olanzapine treatment. Also, fenofibrate increased adiponectin level which was reduced upon olanzapine treatment. Moreover, fenofibrate improved both adipose tissue oxidative stress and inflammatory markers elevation as a result of olanzapine treatment. Fenofibrate could ameliorate olanzapine-induced insulin resistance without affecting its central effect in isolated reared rats via its action on FGF-21-adiponectin axis.

Further insights for the role of Morin in mRTBI: Implication of non-canonical Wnt/PKC-α and JAK-2/STAT-3 signaling pathways

The slightly available data about the pathogenesis process of mild repetitive traumatic brain injury (mRTBI) indicates to the necessity of further exploration of mRTBI consequences. Several cellular changes are believed to contribute to the cognitive disabilities, and neurodegenerative changes observed later in persons subjected to mRTBI. We investigated glial fibrillary acidic protein (GFAP), the important severity related biomarker, where it showed further increase after multiple trauma compared to single one. To authenticate our aim, Morin (10 mg/kg loading dose, then twice daily 5 mg/kg for 7 days), MK-801 (1 mg/kg; i.p) and their combination were used. The results obtained has shown that all the chosen regimens opposed the upregulated dementia markers (Aβ1-40,p(Thr231)Tau) and inflammatory protein contents/expression of p(Ser53s6)NF-κBp65, TNF-α, IL-6,and IL-1β and the elevated GFAP in immune stained cortex sections. Additionally, they exerted anti-apoptotic activity by decreasing caspase-3 activity and increasing Bcl-2 contents. Saving brain tissues was evident after these therapeutic agents via upregulating the non-canonical Wnt-1/PKC-α cue and IL-10/p(Tyr(1007/1008))JAK-2/p(Tyr705)STAT-3 signaling pathway to confirm enhancement of survival pathways on the molecular level. Such results were imitated by correcting the injury dependent deviated behavior, where Morin alone or in combination enhanced behavior outcome. On one side, our study refers to the implication of two survival signaling pathways; viz.,the non-canonical Wnt-1/PKC-α and p(Tyr(1007/1008))JAK-2/p(Tyr705)STAT-3 in single and repetitive mRTBI along with distorted dementia markers, inflammation and apoptotic process that finally disrupted behavior. On the other side, intervention through affecting all these targets by Morin alone or with MK-801 affords a promising neuroprotective effect.

Design, Synthesis and Biological Evaluation of New Cycloalkyl Fused Quinolines Tethered to Isatin Schiff Bases as Cholinesterase Inhibitors

AIMS AND OBJECTIVE

Alzheimer's disease is now a most prevalent neuro degenerative disease of central nervous system leading to dementia in elderly aged population. Numerous pathological changes have been associated in the progression of Alzheimer's disease. One of such pathological hypothesis is declined cholinergic activity which eventually affects cognitive and memory deficits. Inhibition cholinesterases will apparently elevate acetyl choline levels which is benefactor on cognitive symptoms of the disease. This manuscript describes the new tacrine derivatives tethered to isatin Schiff bases through alkanoyl linker and screened for cholinesterase inhibitory activity.

MATERIALS AND METHODS

Tacrine and two more cycloalkyl ring fused quinolones were synthesized and converted to Ncycloalkyl fused quinoline chloroamides. Isatin Schiff bases were also synthesized by the reaction between isatin and substituted aromatic anilines and in subsequent reaction, isatin Schiff bases were reacted with cycloalkyl fused quinolones to afford anticipated compounds 10a-i, 11a-i and 12a-i. All the compounds have been screened for acetyl and butyryl cholinesterase inhibitory activity and in vivo behavioral studies. Binding interactions of the desired compounds have also been studied by docking them in active site of both cholinesterases.

RESULTS

Three compounds 12d, 12e and 12h with propionyl and butyroyl linker between amine and isatin Schiff base scaffold have shown potent acetyl and butyryl cholinesterase inhibitory activity. However most potent cholinesterase inhibitor was 13d with IC50 value of 0.71±0.004 and 1.08±0.02 μM against acetyl and butyryl cholinesterases respectively. The hepatotoxicity of potent compounds revealed that the tested compounds were less hepatotoxic than tacrine and also exhibited encouraging in vivo behavioral studies in test animals. Docking studies of all the molecules disclosed close hydrogen bond interactions within the binding site of both cholinesterases.

CONCLUSION

New cycloalkyl fused quinolones tethered with alkoyl linker to isatin Schiff bases endowed significant and potent cholinesterase inhibitory activities. Few of the compounds have also exhibited lesser hepatotoxicity and all the synthesized compounds were good in behavioral studies. Molecular docking studies also indicated close interactions in active site of cholinesterases.

Rosuvastatin improves olanzapine's effects on behavioral impairment and hippocampal, hepatic and metabolic damages in isolated reared male rats

BACKGROUND & AIM

Schizophrenia is a chronic, disabling neurological illness. This study investigated the effect of rosuvastatin (RSU) addition to the antipsychotic drug: olanzapine (OLZ) in treatment of post-weaning isolation rearing (IR) damaging effect and assessed behavioral impairment, metabolic and hepatic abnormalities, oxidative stress, and inflammatory markers.

METHODS

Treatment with OLZ (6 mg/kg, P.O.) and/or RSU (10 mg/kg, I.P.) have been started 6 weeks after isolation. We assessed behavioral tests, serum cortisol level, and hippocampal content of neurotransmitters. In addition, we assessed histopathology, inflammatory and oxidative stress markers of hippocampus, liver and adipose tissue RESULTS: Treatment of IR animals with OLZ, and/or RSU significantly counteracted the changes in hippocampus, liver and adipose tissue induced by post-weaning IR. Co-treatment of IR rats with both OLZ and RSU showed additive effects in some areas like improving both tumor necrosis factor alpha (TNFα) in both hippocampus and liver, histopathology of liver, oxidative stress markers of adipose tissue, β₃ adrenergic receptors (ADRβ₃), serum cortisol and total cholesterol. In addition, RSU alone alleviated the damage of IR rats by the same efficacy as OLZ with more benefit in cognition and exploration.

CONCLUSION

post-weaning IR as a model has behavioral, hippocampal, hepatic and marked metabolic changes more relevant to schizophrenia than drug-induced models. These effects were ameliorated by RSU and/or OLZ that are explained by their antioxidant, anti-inflammatory, anti-stress and anti-hyperlipidemic properties. Interestingly, co-treatment with both drugs showed a better effect.

A rapid chemical-genetic screen utilizing impaired movement phenotypes in C. elegans: Input into genetics of neurodevelopmental disorders

Autism spectrum disorder (ASD) is the most common neurodevelopmental disorder with a constantly increasing prevalence. Model organisms may be tools to identify underlying cellular and molecular mechanisms, as well as aid the discovery and development of novel therapeutic approaches. A simple animal such as the nematode Caenorhabditis elegans may provide insights into the extreme complexity of ASD genetics. Despite its potential, using C. elegans in ASD research is a controversial approach and has not yet been used extensively in this context. In this study, we present a screening approach of potential C. elegans mutants as potential ASD models. We screened these mutants for motor-deficiency phenotypes, which can be exploited to study underlying mechanisms of the disorder. Selected motor-deficient mutants were then used in a comprehensive drug screen of over 3900 compounds, including many FDA-approved and natural molecules, that were analyzed for their ability to suppress motility defects caused by ASD-associated gene orthologues. This genetic-chemical approach, i.e. establishing C. elegans models for ASD and screening of a well-characterized compound library, might be a promising first step to understand the mechanisms of how gene variations cause neuronal dysfunction, leading to ASD and other neurological disorders. Positively acting compounds could also be promising candidates for preclinical studies.

Characterization of a novel putative cognition enhancer mediating facilitation of glycine effect on strychnine-resistant sites coupled to NMDA receptor complex

The effects of (S)-4-amino-5-[(4,4-dimethylcyclohexyl)amino]-5-oxo-pentanoic acid ((S)CR 2249), a new chemical entity selected among a series of glutamic acid derivatives, were investigated on N-methyl-D-aspartate (NMDA)-evoked release of [3H]noradrenaline from rat hippocampal slices. (S)CR 2249 facilitated glycine-mediated reversion of kynurenate antagonism at strychnine-insensitive glycine receptors coupled to the NMDA receptor. The potency of glycine (EC50 = 21.5 microM +/- 4.2) was not significantly influenced by (S)CR 2249. Nevertheless, the efficacy of the glycine effect was enhanced in a concentration-dependent manner (3-10-30 microm) by (S)CR 2249. The interaction of (S)CR 2249 with NMDA receptors was also studied with binding experiments, in which we examined the effect of (S)CR 2249 on the modulation by glutamate, glycine and spermine of [3H]dizocilpine (MK-801) binding. (S)CR 2249, increased [3H]MK-801 binding in a concentration-dependent manner and we found positive cooperative interactions between glycine and (S)CR 2249, indicating that (S)CR 2249 probably acts at a separate allosteric site to increase NMDA receptor functionality.