In Silico-and In Vivo-based Screening Of Food-derived And Synthetic Compounds Against Alzheimer’s Disease

Aging is one of the risk factors for Alzheimer’s disease(AD)in the world.This disease is characterized by neuronal dysfunction and increased morbidity related to cognitive functions and living style.Pathogenic aging is regarded as asymptomatic AD with no cognitive deficit except for neuropathology.These individuals are highly susceptible to AD.The brain’s temporal cortex region is an initiation site for early AD progression and a center for cognitive processing.So,the hub gene of this region may reveal early altered biological cascades that may be helpful to alleviate AD in an early stage.To date,not a single effective therapy is present that can prevent or recover AD pathology.However,several disease-modulatory FDAapproved drugs are being used in patients with neurodegenerative diseases but these synthetic drugs cause adverse effects on human health.Some of the common neurological symptoms due to side effects of the drug are headache,insomnia,dizziness,and mood disturbances,as well as injuries to the nerve cells that sometimes may impair vision.To increase the focus on drug safety and reduce the associated risks,recognition of its associated toxicity is very concerning.However,information on their toxicity-related profiles is very limited.Therefore,measurement of drug toxicity is essential to increase the knowledge of their side effects and the progress of advanced therapeutic approaches is required to overcome these problems.Currently,the natural bioactive compounds derived from food have been emphasized to have neuroprotective efficacy with multiple antioxidant and anti-inflammatory properties that may improve pathological conditions of AD.Significantly,many studies are proposing bioactive compounds as an effective treatment for AD due to their ancient medicinal history and nutritional and multidimensional targeting properties.These multifaceted properties of bioactive compounds are modulators of oxidative stress and neuroinflammation and hamper Amyloid accretion and tau tangles production.Thus,these functional properties can act on several stages of AD pathology to improve the disease state.Meanwhile,the multi-nutritional features of these bioactive compounds in elderly people with AD seem very promising in improving cognitive functions.Several studies suggest a correlation between the lower status of the body’s micronutrients,protein,and energy with progression in disease pathology in mild AD patients.Nutrient deficiencies strongly contribute to AD progression because the intake of dietary bioactive compounds rich in antioxidants,B vitamins,n-3 polyunsaturated fatty acids,and docosahexaenoic acid have been significantly efficacious in neuroprotection in AD patients.So,in this study,we have evaluated the drug’s toxicity and therapeutic efficiency of natural bioactive compounds to cure AD pathologies.In the first study,we aimed to identify compounds that can modulate M-cell regeneration by causing neuroprotection and-toxicity.Here,we developed a simple and efficient in vivo assay using Tg(hsp: Gal4FF62A;UAS: nfs B-m Cherry)transgenic zebrafish larvae.Interestingly,via the phenotype-based drug screening approach,we rapidly investigated1260 compounds from the US drug collection and validated these in large numbers,including14 compounds,that were obstructing this regeneration process.Next,4 FDA-approved drugs out of 14 compounds were selected as the lead hits for in silico analysis to clarify their binding patterns with PTEN and SOCS3 signaling and their significant potential in the inhibition of axon regeneration.Molecular docking studies indicated good binding affinity of all 4 drugs with the respective signaling molecules.This may point to PTEN and SOCS3 as the signaling molecules responsible for reducing axon regeneration.Moreover,the acute effect of compounds in reducing M-cell regeneration delineated their toxic effect.In conclusion,our in vivo along with in silico screening strategy will promote the rapid translation of new therapeutics to improve knowledge of the toxicity profile of approved/non-approved drugs efficiently.In the second study,we aimed to explore changes in gene expression of aged control,asymptomatic AD(Asym AD),and symptomatic AD(sym AD)in the temporal cortex region.We used microarray data sets to identify differentially expressed genes(DEGs)with the help of the R programming interface.Further,we conducted Gene Ontology(GO)enrichment analysis via Bioconductor’s cluster profile package.And by performing the STRING plugin in Cytoscape,we constructed the protein-protein interaction(PPI)network and determined the hub genes via the Cyto Hubba plugin.Resultant,the Asym AD transcriptome revealed the earlystage changes of glutamatergic hyperexcitability.Whereas the connectivity of major hub genes in this network indicates a shift from initially reduced r RNA biosynthesis in the Asym AD group to impaired protein synthesis in the sym AD group.Both share the phenomenon of breaking tight junctions and others.In conclusion,this study offers new understandings of the early biological variations in the brain before the manifestation of sym AD and gives promising therapeutic targets for early AD intervention.In the third study,we searched works of literature and found that with an unprecedented rise in older adults,AD has become a burden in which eternal inflammation impairs memory and cognitive functions.Cerebral inflammation is a crucial driver of AD progression,where hyperactivity of immune cells exacerbates the overall disease state.OAS-1 protein is associated with the innate activity of immune cells.However,recent findings suggest a strong correlation between amyloid buildup and increased expression of OAS-1.Its sustained elevation has been identified as a causing factor of chronic neuroinflammation,leading to subsequent cognitive decline.Increment in the expression of OAS-1 in Alzheimer’s disease has been identified in various GWAS and in vivo studies,suggesting it to be a strong candidate for drug discovery.However,due to the limited efficacy of currently available treatments,the search for more effective therapies has drawn attention to dietary interventions,controlling neuroinflammation.A multifaceted approach to counteract AD might be beneficial.Dietary bioactive compounds are well recognized for their multifunctional neuroprotective activity by interacting with neurotoxic proteins.Therefore,we aimed to identify potential natural inhibitors against the OAS-1 protein via molecular docking followed by molecular dynamics and free energy estimation.This in silico study successfully investigated the inhibitory activity of biphenyl amides enriched in half-highbush blueberries in targeting OAS-1.Thus,biphenyl amides can be an efficient inhibitor contributing to the amelioration of AD pathology.In the fourth study,based on recent research,we found the age-dependent upregulation of BACE-1 and MAO-B involvement in the pathogenesis of AD by impairing many biological pathways of Aβ processing,microglial and astrocytes,brain vasculature,and metabolic cascades.Therefore,these novel functions of both target proteins make them druggable targets for AD therapeutics.Phytochemicals are of great interest for drug discovery because of their multifunctional activity within a single molecule,such as antioxidant,anti-inflammatory,and anti-Alzheimer’s pathological properties.In this study,we utilized a target-based approach to mine the natural inhibitors against both target proteins via performing molecular docking and molecular dynamics(MD)simulation.Here,we selected the best hits based on significant binding affinity.And structural fluctuations and entropic effects were predicted by dynamic simulations to ensure the stability of the complex interactions.Our results indicated that foodbioactive compounds flavin and purine derivatives showed good binding affinity against both target proteins,suggesting their efficacy in improving this deleterious disease condition.Overall,we explored the therapeutic potential of several natural bioactive compounds against AD and developed a drug screening assay.Meanwhile,we found ten novel genes related to AD via omics study which were not described before.Significantly,this study successfully defines the neurotoxicity of synthetic drugs,which suggests a preference for bioactive compounds over them.Moreover,in silico structure-based methods helped us to identify several prominent bioactive compounds from blueberry whole grains,kelp,and other dietary resources with neuroprotective efficiency against abnormally expressing proteins which may help in improving AD pathology.