Discovery of MAO-B Inhibitor with Machine Learning, Topomer CoMFA, Molecular Docking and Multi-Spectroscopy Approaches

Alzheimer’s disease (AD) is the most common type of dementia and is a serious disruption to normal life. Monoamine oxidase-B (MAO-B) is an important target for the treatment of AD. In this study, machine learning approaches were applied to investigate the identification model of MAO-B inhibitors. The results showed that the identification model for MAO-B inhibitors with　K-nearest neighbor(KNN) algorithm had a prediction accuracy of 94.1% and 88.0% for the 10-fold cross-validation test and the independent test set, respectively. Secondly, a quantitative activity prediction model for MAO-B was investigated with the Topomer CoMFA model. Two separate cutting mode approaches were used to predict the activity of MAO-B inhibitors. The results showed that the cut model with q² = 0.612 (cross-validated correlation coefficient) and r² = 0.824 (non-cross-validated correlation coefficient) were determined for the training and test sets, respectively. In addition, molecular docking was employed to analyze the interaction between MAO-B and inhibitors. Finally, based on our proposed prediction model, 1-(4-hydroxyphenyl)-3-(2,4,6-trimethoxyphenyl)propan-1-one (LB) was predicted as a potential MAO-B inhibitor and was validated by a multi-spectroscopic approach including fluorescence spectra and ultraviolet spectrophotometry.

Neuropsychiatric Symptoms Assessment: Cross-cultural Adaptation and Validation of the Portuguese Abe's BPSD Score (ABS)

OBJECTIVES

This study aims to report on the development and psychometric properties of the Portuguese-language Abe's BPSD score (ABS) to screen for neuropsychiatric symptoms (NPS).

METHODS

ISPOR and COSMIN recommendations were followed to translate and culturally adapt the ABS. A validation study was conducted to assess the psychometric properties of the newly-translated instrument. Outpatients attending a psychogeriatric consultation were included by consecutive referrals and were assessed with the ABS, the Neuropsychiatric Inventory (NPI) and NPI Caregiver Distress scale (NPI-D), and the Mini-Mental State Examination (MMSE). The ABS reliability (internal consistency, item-total correlations, inter-rater and test-retest reliability), validity (concurrent and convergent), feasibility and diagnostic accuracy were examined.

RESULTS

Overall, 107 participants were included. The ABS Cronbach alpha was 0.672, and item-total correlations ranged from -0.056 to 0.546. Strong inter-rater (ICC 0.997; 95%CI: 0.995-0.999) and test-retest reliability (ICC 0.976; 95%CI: 0.958-0.986) were found. Concurrent validity with NPI was high (r_s = 0.847, p < .001), and correlations with MMSE and NPI-D were also significant. An exploratory threshold score ≥2 is proposed to identify clinically relevant NPS.

CONCLUSIONS

Data provide satisfactory proof of ABS psychometric characteristics. Nevertheless, some items exhibited less optimal properties.

CLINICAL IMPLICATIONS

The newly-translated instrument proved to be relevant, valid and easy to use in a real geriatric clinical setting.

Effect of the MAGL/FAAH Dual Inhibitor JZL-195 on Streptozotocin-Induced Alzheimer's Disease-like Sporadic Dementia in Mice with an Emphasis on Aβ, HSP-70, Neuroinflammation, and Oxidative Stress

Alzheimer's disease is identified by pathological hallmarks such as intracellular neurofibrillary tangles (NFTs) and extracellular amyloid β plaques. Several hypotheses exist to define the neurodegeneration including microglial activation associated with neuroinflammatory processes. Recently, pharmacological inhibition of endocannabinoid (eCB)-degrading enzymes, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), is being investigated to modulate the pathology of Alzheimer's disease. While MAGL inhibitors upregulate 2-acyl glycerol (2-AG) levels and reduce neuroinflammation, FAAH inhibitors elevate anandamide (AEA) levels and prevent the degradation of HSP-70, thereby preventing the phosphorylation of tau protein and formation of NFTs in neural cells. We investigated the possible neuroprotective potential of the dual MAGL/FAAH inhibitor JZL-195 (20 mg/kg) against ICV-STZ-induced sporadic Alzheimer's disease (SAD) in Swiss albino mice using donepezil (5 mg/kg) as the standard. The protective effects of JZL-195 were observed by the reversal of altered levels of Aβ_1-42, HSP-70, neuroinflammatory cytokines, and oxidative stress markers. However, JZL-195 expressed no cognitive improvement when assessed by spontaneous alternation behavior and Morris water maze tests and no effects on the AChE enzyme level in the hippocampal tissues of mice. Therefore, the findings of the present study indicate that although JZL-195 exhibited no improvement in cognitive deficits associated with sporadic Alzheimer's disease, it displayed significant reversal of the biochemical anomalies, thereby suggesting its therapeutic potential against the sporadic Alzheimer's disease model.

Risk of overactive bladder associated with cholinesterase inhibitors in dementia

BACKGROUND

Although cholinesterase inhibitors (ChEIs) are the primary treatment for dementia, they are associated with overactive bladder (OAB), necessitating antimuscarinic use. Limited data exist regarding the risk of OAB across individual ChEIs in dementia. This study evaluated the risk of OAB associated with individual ChEIs in older adults with dementia.

METHODS

This was a new user retrospective cohort study using Medicare claims data involving Parts A, B, and D claims dataset from 2013 to 2015. The study included older adults (aged 65 and older) with a diagnosis of dementia using donepezil, galantamine, or rivastigmine. New ChEI claims were identified with a 6-month baseline washout period. Patients with OAB diagnosis or any antimuscarinic or mirabegron use in the baseline period were excluded. The primary outcome of interest was OAB diagnosis or prescription of antimuscarinics or mirabegron within 6 months of ChEI initiation. Multivariable cox proportional hazards regression with propensity scores (PS) as covariates and inverse probability of treatment weighting generated using generalized boosted models was used to assess the risk of OAB among donepezil, galantamine, and rivastigmine users.

RESULTS

The study included 524,975 older adults with dementia who were incident users of ChEIs (donepezil 80.72%, rivastigmine 16.41%, galantamine 2.87%). Overall, OAB diagnosis/antimuscarinic/mirabegron prescription was observed in 5.07% of the cohort within 6 months of ChEIs prescription. The Cox regression model with PS as covariate approach found that donepezil use increased the risk of OAB compared to rivastigmine (aHR, 1.13; 95% CI, 1.08-1.28; p < 0.0001). However, there was no differential risk of OAB between galantamine and rivastigmine. The findings were consistent with the generalized boosted models.

CONCLUSIONS

The study found that the risk of OAB varies across individual ChEIs with an increased risk of OAB with donepezil compared to rivastigmine. The study findings suggest the need to understand and manage medication-related morbidity in older adults with dementia.

Inhibitory Effect of Hexahydrocurcumin on Memory Impairment and Amyloidogenesis in Dexamethasone-Treated Mice

A high dose of dexamethasone induces neurodegeneration by initiating the inflammatory processes that lead to neural apoptosis. A dexamethasone administration model induces overproduction of amyloid-β (Aβ) and tau protein hyperphosphorylation and shows abnormalities of cholinergic function similar to Alzheimer's disease (AD). This study aimed to investigate the protective effect of hexahydrocurcumin on the brain of dexamethasone-induced mice. The results showed that hexahydrocurcumin and donepezil attenuated the levels of amyloid precursor protein and β-secretase mRNA by reverse transcription polymerase chain reaction, decreased the expression of hyperphosphorylated tau, and improved synaptic function. Moreover, we found that hexahydrocurcumin treatment could decrease interleukin-6 levels by attenuating p65 of nuclear factor kappa-light-chain-enhancer (NF-κB) of activated beta cells. In addition, hexahydrocurcumin also decreased oxidative stress, as demonstrated by the expression of 4-hydroxynonenal and thereby prevented apoptosis. Therefore, our finding suggests that hexahydrocurcumin prevents dexamethasone-induced AD-like pathology and improves memory impairment.

Alendronate reduces the cognitive and neurological disturbances induced by combined doses of d-galactose and aluminum chloride in mice

Neurological disturbances including cholinergic dysfunction, oxidative stress, neuroinflammation, and cognitive impairments are the well-reported consequences of old age-related disorders like Alzheimer's disease (AD) or dementia. Bisphosphonates were shown to ameliorate dementia in osteoporotic patients, neuroinflammation, and cholinesterase activity in rodents. Thus, the present study has been designed to examine the role of alendronate against cognitive and neurological disturbances in mice induced by a combined oral dose of d-galactose and aluminum chloride (AlCl₃ ) for 6 weeks. d-galactose acts as a senescence agent, whereas AlCl₃ is a neurotoxin and in combination generates neuropathologies and cognitive depletion resembling aging and AD. It was found that memory was markedly impaired in d-galactose + AlCl₃ -treated mice as assessed in different behavioral paradigms. Additionally, d-galactose + AlCl₃ led to neurotoxicity assessed on the basis of neuroinflammation, oxidative stress, glial cell activation, neuronal damage, and augmented GSK-3β level in mice hippocampus. Consequently, alendronate administration orally for 15 days in d-galactose + AlCl₃ -exposed mice prominently reversed all these behavioral and neuropathological changes. These findings show that alendronate can be a potential therapeutic molecule with multiple targets for the management of age-related neurological disorders such as AD.

An acetylcholinesterase-based biosensor for the detection of pesticides using liquid crystals confined in microcapillaries

Here, we demonstrate a capillary-sensing platform based on liquid crystals (LCs) confined in microcapillaries for simple and sensitive detection of acetylcholinesterase (AChE) and its inhibitors. LC droplets were formed through sequential injection of LCs and an aqueous solution into trichloro(octyl)silane (OTS)-treated microcapillaries. When the confined LC droplets make contact with a cationic surfactant solution, myristoylcholine chloride (Myr), the formation of a Myr monolayer at the aqueous/LC interface induces a horizontal orientation of the LCs at the interface along the microcapillary, producing an optical LC droplet texture of a four-petal shape. On the other hand, AChE can catalyze the hydrolysis of Myr into choline and myristic acid. The hydrolyzed Myr is unable to form a monolayer at the aqueous/LC interface, and therefore the confined LC droplets exhibit two bright-lined optical images when in contact with the pre-incubated mixture of Myr and AChE, corresponding to the homeotropic orientation of LCs at the interface. However, in the presence of AChE-inhibiting pesticides, such as fenobucarb and malathion, the activity of AChE is inhibited, and thus, the enzymatic hydrolysis of Myr cannot occur. As a result, the confined LC droplets present the four petal-shaped optical images when in contact with the pre-incubated mixture of Myr, AChE, and pesticides. Based on this principle, an LC-based microcapillary sensor was developed and utilized for the detection of pesticides. Using this sensing platform, fenobucarb and malathion were detected at limits of 5 pg/mL and 2.5 pg/mL, respectively. Moreover, the proposed biosensor was successfully applied to the determination of pesticides in real river water. Therefore, this LC-based microcapillary sensor is a promising platform for simple, rapid, and label-free detection of pesticides with very high sensitivity.

The Efficacy of Sertraline, Escitalopram, and Nicergoline in the Treatment of Depression and Apathy in Alzheimer's Disease: The Okayama Depression and Apathy Project (ODAP)

BACKGROUND

Neuropsychiatric symptoms of dementia such as depression and apathy in patients with Alzheimer's disease (AD) are associated with a lower quality of life.

OBJECTIVE

We aimed to determine the efficacy of two antidepressants and one antipathy drug in the treatment of depression and apathy in AD patients.

METHODS

In the present study, we evaluated the efficacy of sertraline (n = 11; average dose = 31.8 mg), escitalopram (n = 13; average dose = 7.3 mg), and nicergoline (n = 9; average dose = 14.5 mg) in treating depression and apathy over a period of 3 months (M).The 33 patients with AD demonstrated high Geriatric Depression Scale (GDS) (>5) or a high Apathy Scale (AS) (>16) scores.

RESULTS

The patients receiving escitalopram treatment showed a significant improvement in GDS score from baseline (8.2±3.5) to 3 M (5.7±2.6, p = 0.04), and the patients receiving sertraline treatment showed a significant improvement in AS score from baseline (20.8±5.2) to 3 M (16.8±6.1, p = 0.05); however, no significant changes were noted in patients receiving nicergoline.

CONCLUSION

These results provide novel information on the efficacy of sertraline and escitalopram in the treatment of apathy and depression, respectively, in patients with AD.

Neuroprotective role of alendronate against APP processing and neuroinflammation in mice fed a high fat diet

Obesity and consumption of diet rich in fat are known to contribute to the development of Alzheimer's disease (AD) which is a complex and multifactorial neurodegenerative disease and a leading cause of mortality with unmet medical needs. Hypercholesterolemia was discovered to increase neuropathological changes along with cognitive decline in AD mouse models but still the underlying mechanism is elusive. Furthermore, isoprenoids, the crucial products of Mevalonate-pathway produced by the action of farnesyl pyrophosphate synthase (FPPS) enzyme, are also demonstrated to play a key role in AD. Nevertheless, bisphosphonates target this enzyme in order to treat osteoporosis and also found to alleviate dementia in such patients. As per the cited inhibitory action of alendronate, against acetylcholinesterase and cholesterol level, we hypothesized to explore the potential of alendronate against high fat diet (HFD) induced neuropathologies and cognitive disabilities in AD mouse model. Here we noticed that in mice provided with HFD for 14 weeks, spatial memory was compromised as interpreted in different behavioral paradigms. Together with cognitive depletion, there was observed a provoking effect on amyloid precursor protein (APP)-processing via amyloidogenic pathway due to enhanced β-site APP cleaving enzyme-1 (BACE-1) level which in turn leads to augmented release of amyloid beta (Aβ) in hippocampus of HFD mice. Relevant to these, significant elevation in hippocampal level of neuroinflammatory cytokines, oxidative stress markers and isoprenoids and serum cholesterol were also found after HFD exposure. Marked reversal of cognitive impairment, enhanced APP-processing, neuroinflammation along with other neuropathological alterations in hippocampus was demonstrated following oral administration of alendronate (1.76 mg/kg) for 15 days despite of HFD treatment. These changes were noted to be due to modulation of isoprenoids and cholesterol level by alendronate. Supporting these, histopathological analysis done by congo red revealed the reduced Aβ deposition in hippocampus of drug treated HFD mice The current outcomes provide important implications for the contribution of Mevalonate-pathway and HFD for the onset of AD and also support alendronate as a prominent intervention for amelioration of AD-like pathologies.

Pharmacotherapy of Alzheimer's Disease: Seeking Clarity in a Time of Uncertainty

Alzheimer's disease (AD) is recognized as a major health hazard that mostly affects people older than 60 years. AD is one of the biggest medical, economic, and social concerns to patients and their caregivers. AD was ranked as the 5th leading cause of global deaths in 2016 by the World Health Organization (WHO). Many drugs targeting the production, aggregation, and clearance of Aβ plaques failed to give any conclusive clinical outcomes. This mainly stems from the fact that AD is not a disease attributed to a single-gene mutation. Two hallmarks of AD, Aβ plaques and neurofibrillary tangles (NFTs), can simultaneously induce other AD etiologies where every pathway is a loop of consequential events. Therefore, the focus of recent AD research has shifted to exploring other etiologies, such as neuroinflammation and central hyperexcitability. Neuroinflammation results from the hyperactivation of microglia and astrocytes that release pro-inflammatory cytokines due to the neurological insults caused by Aβ plaques and NFTs, eventually leading to synaptic dysfunction and neuronal death. This review will report the failures and side effects of many anti-Aβ drugs. In addition, emerging treatments targeting neuroinflammation in AD, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and receptor-interacting serine/threonine protein kinase 1 (RIPK1), that restore calcium dyshomeostasis and microglia physiological function in clearing Aβ plaques, respectively, will be deliberately discussed. Other novel pharmacotherapy strategies in treating AD, including disease-modifying agents (DMTs), repurposing of medications used to treat non-AD illnesses, and multi target-directed ligands (MTDLs) are also reviewed. These approaches open new doors to the development of AD therapy, especially combination therapy that can cater for several targets simultaneously, hence effectively slowing or stopping AD.

A Series of New Hydrazone Derivatives: Synthesis, Molecular Docking and Anticholinesterase Activity Studies

BACKGROUND

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are known to be serine hydrolase enzymes responsible for the hydrolysis of acetylcholine (ACh), which is a significant neurotransmitter for regulation of cognition in animals. Inhibition of cholinesterases is an effective method to curb Alzheimer's disease, a progressive and fatal neurological disorder.

OBJECTIVE

In this study, 30 new hydrazone derivatives were synthesized. Then we evaluated their anticholinesterase activity of compounds. We also tried to get insights into binding interactions of the synthesized compounds in the active site of both enzymes by using molecular docking approach.

METHODS

The compounds were synthesized by the reaction of various substituted/nonsubstituted benzaldehydes with 6-(substitute/nonsubstituephenyl)-3(2H)-pyridazinone-2-yl propiyohydrazide. Anticholinesterase activity of the compounds was determined using Ellman's method. Molecular docking studies were done by using the ADT package version 1.5.6rc3 and showed by Maestro. RMSD values were obtained using Lamarckian Genetic Algorithm and scoring function of AutoDock 4.2 release 4.2.5.1 software.

RESULTS

The activities of the compounds were compared with galantamine as cholinesterase enzyme inhibitor, where some of the compounds showed higher BChE inhibitory activity than galantamine. Compound F111 was shown to be the best BChE inhibitor effective in 50 μM dose, providing 89.43% inhibition of BChE (IC50=4.27±0.36 μM).

CONCLUSION

This study supports that novel hydrazone derivates may be used for the development of new BChE inhibitory agents.

Bridging the Gap between Alzheimer's Disease and Alzheimer's-like Diseases in Animals

The average life span steadily grows in humans and in animals kept as pets or left in sanctuaries making the issue of elderly-associated cognitive impairment a hot-spot for scientists. Alzheimer’s disease (AD) is the most prevalent cause of progressive mental deterioration in aging humans, and there is a growing body of evidence that similar disorders (Alzheimer’s-like diseases, ALD) are observed in animals, more than ever found in senescent individuals. This review reveals up to date knowledge in pathogenesis, hallmarks, diagnostic approaches and modalities in AD faced up with ALD related to different animal species. If found at necropsy, there are striking similarities between senile plaques (SP) and neurofibrillary tangles (NFT) in human and animal brains. Also, the set of clinical symptoms in ALD resembles that observed in AD. At molecular and microscopic levels, the human and animal brain histopathology in AD and ALD shows a great resemblance. AD is fatal, and the etiology is still unknown, although the myriad of efforts and techniques were employed in order to decipher the molecular mechanisms of disease onset and its progression. Nowadays, according to an increasing number of cases reported in animals, apparently, biochemistry of AD and ALD has a lot in common. Described observations point to the importance of extensive in vivo models and extensive pre-clinical studies on aging animals as a suitable model for AD disease.

Ameliorative effect of alendronate against intracerebroventricular streptozotocin induced alteration in neurobehavioral, neuroinflammation and biochemical parameters with emphasis on Aβ and BACE-1

Alzheimer's disease (AD) is the most prevalent age related neurodegenerative disorder manifested by progressive cognitive decline and neuronal loss in the brain, yet precise etiopathology of majority of sporadic or late-onset AD cases is unknown. AD is associated with various pathological events such as Aβ deposition due to BACE-1 induced cleavage of APP, neuroinflammation, increased cholesterol synthesis, cholinergic deficit and oxidative stress. It was found that bone drug, alendronate (ALN) that cross blood brain barrier inhibits brain cholesterol synthesis and AChE enzyme activity. As cholesterol modifying agents have been supposed to alter AD like pathologies, the current study was designed to investigate the possible neuroprotective and therapeutic potential of ALN against ICV STZ induced experimental sporadic AD (SAD) in mice in a non-cholesterol dependent manner, using donepezil (5 mg/kg) as a reference standard. The preliminary study was done by molecular modelling to identify the binding affinity of ALN with BACE-1 in silico. The prevention of cognitive impairment in mice induced by ICV STZ (3 mg/kg) infused on first and third day, by ALN (1.76 mg/kg p.o.) administered for 15 consecutive days was assessed through Spontaneous Alternation Behavior (SAB) and Morris water maze (MWM) test. Additionally, the protective effect of ALN was also observed by the reversal of altered levels of Aβ_1-42, BACE-,1 neuroinflammatory cytokines, AChE activity and oxidative stress markers (except TBARS) in ICV-STZ infused mice. However, the findings of the present study imply the therapeutic potential of ALN against SAD-like complications.