Multitarget action of Benzothiazole-piperazine small hybrid molecule against Alzheimer's disease: In silico, In vitro, and In vivo investigation.

A novel small molecule based on benzothiazole-piperazine has been identified as an effective multi-target-directed ligand (MTDL) against Alzheimer's disease (AD). Employing a medicinal chemistry approach, combined with molecular docking, MD simulation, and binding free energy estimation, compound 1 emerged as a potent MTDL against AD. Notably, compound 1 demonstrated efficient binding to both AChE and Aß1-42, involving crucial molecular interactions within their active sites. It displayed a binding free energy (ΔGbind) -18.64± 0.16 and -16.10 ± 0.18 kcal/mol against AChE and Aß1-42, respectively. In-silico findings were substantiated through rigorous in vitro and in vivo studies. In vitro analysis confirmed compound 1 (IC50=0.42 µM) as an effective, mixed-type, and selective AChE inhibitor, binding at both the enzyme's catalytic and peripheral anionic sites. Furthermore, compound 1 demonstrated a remarkable ability to reduce the aggregation propensity of Aß, as evidenced by Confocal laser scanning microscopy and TEM studies. Remarkably, in vivo studies exhibited the promising therapeutic potential of compound 1. In a scopolamine-induced memory deficit mouse model of AD, compound 1 showed significantly improved spatial memory and cognition. These findings collectively underscore the potential of compound 1 as a promising therapeutic candidate for the treatment of AD.

Development of novel carbazole derivatives with effective multifunctional action against Alzheimer's diseases: Design, synthesis, in silico, in vitro and in vivo investigation.

Carbazole based novel multifunctional agents has been rationally designed and synthesized as potential anti-Alzheimer agents. Multi-functional activity of these derivatives have been assessed by performing various in-vitro assays and these compounds appeared to be potent AChE inhibitors, Aß aggregation inhibitors, anti-oxidant and neuroprotective agents. Among the entire series, MT-1 and MT-6 were most potent multifunctional agents which displayed effective and selective AChE inhibition, Aß disaggregation, anti-oxidant and metal chelation action. Neuroprotective activity of MT-6 has been examined against H2O2 induced toxicity in SHSY-5Y cells and they have shown effective neuroprotection. Additionally, MT-6 did not display any significant toxicity in SHSY-5Y cells, indicating its non-toxic nature. Molecular docking and MD simulation studies have been also performed to explore molecular level interaction with AChE and Aß. Finally, MT-6 was evaluated against scopolamine induced dementia model of mice and this compound actively improved memory deficit and cognition impairment in scopolamine treated mice. Thus, novel carbazole derivative MT-6 has been explored as an effective and safe multifunctional agent against AD and this molecule may be used as a suitable lead for development of effective anti-Alzheimer agents in future.

Development of novel N-(6-methanesulfonyl-benzothiazol-2-yl)-3-(4-substituted-piperazin-1-yl)-propionamides with cholinesterase inhibition, anti-ß-amyloid aggregation, neuroprotection and cognition enhancing properties for the therapy of Alzheimer's disease.

A novel series of benzothiazole-piperazine hybrids were rationally designed, synthesized, and evaluated as multifunctional ligands against Alzheimer's disease (AD). The synthesized hybrid molecules illustrated modest to strong inhibition of acetylcholinesterase (AChE) and Aß1-42 aggregation. Compound 12 emerged as the most potent hybrid molecule exhibiting balanced functions with effective, uncompetitive and selective inhibition against AChE (IC50 = 2.31 µM), good copper chelation, Aß1-42 aggregation inhibition (53.30%) and disaggregation activities. Confocal laser scanning microscopy and TEM analysis also validate the Aß fibril inhibition ability of this compound. Furthermore, this compound has also shown low toxicity and is capable of impeding loss of cell viability elicited by H2O2 neurotoxicity in SHSY-5Y cells. Notably, compound 12 significantly improved cognition and spatial memory against scopolamine-induced memory deficit in a mouse model. Hence, our results corroborate the multifunctional nature of novel hybrid molecule 12 against AD and it may be a suitable lead for further development as an effective therapeutic agent for therapy in the future.

Naphthalene-triazolopyrimidine hybrid compounds as potential multifunctional anti-Alzheimer's agents.

In an attempt to construct potential anti-Alzheimer's agents Naphthalene-triazolopyrimidine hybrids were synthesized and screened in vitro against the two cholinesterases (ChE)s, amyloid ß aggregation and for antioxidation activity. Single-crystal X-ray crystallography was utilized for crystal structure determination of one of the compounds. In vitro study of compounds revealed that most of the compounds are capable of inhibiting acetylcholinesterase and Butyrylcholinesterase activity. Particularly, the compounds 4e and 4d exhibited IC50 values ranging from 8.6 to 14 nM against AChE lower than the standard drug Donepezil (IC50 49 nM). Best result was found for compound 4e with IC50 of 8.6 nM (for AChE) and 150 nM (for BuChE). Selectivity upto that of Donepezil and even more was observed for 4a, 4c and 4h. Investigation by electron microscopy, transmission electron microscopy and ThT fluorescence assay unveils the fact that synthesized hybrids exhibit amyloid ß self-aggregation inhibition. The compounds 4i and 4j revealed highest inhibitory potential, 85.46% and 72.77% at 50 µM respectively; above the standard Aß disaggregating agent, Curcumin. Their antioxidation profile was also analyzed. Studies from DPPH free radical scavenging assay and ORAC assay depicts molecules to possess low antioxidation profile. Results suggest that triazolopyrimidines are potential candidate for Acetylcholinesterase (AChE), Butyrylcholinesterase (BuChE), and amyloid ß aggregation inhibition. In silico ADMET profiling indicates drug-like properties with a very low toxic influence. Such synthesized compounds provide a strong vision for further development of potential anti-Alzheimer's agents.

A multifunctional therapeutic approach: Synthesis, biological evaluation, crystal structure and molecular docking of diversified 1H-pyrazolo[3,4-b]pyridine derivatives against Alzheimer's disease.

2-(piperazin-1-yl)N-(1H-pyrazolo[3,4-b]pyridin-3-yl)acetamides are described as a new class of selective and potent acetylcholinesterase (AChE) inhibitors and amyloid ß aggregation inhibitors. Formation of synthesized compounds (P1P9) was justified via H1 NMR, C13 NMR, mass spectra and single crystal X-Ray diffraction study. All compounds were evaluated for their acetylcholinesterase and butyrylcholinesterase inhibitory activity, inhibition of self-mediated Aß aggregation and Cu(II)-mediated Aß aggregation. Also, docking study carried out was in concordance with in vitro results. The most potent molecule amongst the derivatives exhibited excellent anti-AChE activity (IC50 = 4.8 nM). Kinetic study of P3 suggested it to be a mixed type inhibitor. In vitro study revealed that all the compounds are capable of inhibiting self-induced ß-amyloid (Aß) aggregation with the highest inhibition percentage to be 81.65%. Potency of P1 and P3 to inhibit self-induced Aß1-42 aggregation was ascertained by TEM analysis. Compounds were also evaluated for their Aß disaggregation, antioxidation, metal-chelation activity.

New amyloid beta-disaggregating agents: synthesis, pharmacological evaluation, crystal structure and molecular docking of N-(4-((7-chloroquinolin-4-yl)oxy)-3-ethoxybenzyl)amines.

In the journey towards the development of potent multi-targeted ligands for the treatment of Alzheimer's disease, a series of Aß aggregation inhibitors having quinoline scaffold were designed utilizing computational biology tools, synthesized and characterized by various spectral techniques including single-crystal X-ray crystallography. Organic syntheses relying upon convergent synthetic routes were employed. Investigations via ThT fluorescence assay, electron microscopy and transmission electron microscopy revealed the synthesized derivatives to exhibit Aß self-aggregation inhibition. Molecules 5g and 5a showed the highest inhibitory potential, 53.73% and 53.63% at 50 µM respectively; higher than the standard Aß disaggregating agent, curcumin. Molecules 5g and 5a disaggregated AChE-induced (58.26%, 47.36%) Aß aggregation more than two fold more than the standard drug-donepezil (23.66%) and inhibited Cu2+-induced Aß aggregation. A docking study significantly showed their interaction with key residues of Aß and the results were in accordance with the study. Besides, these compounds also exhibited potential antioxidant activity (5a, 2.7240 Trolox equivalent by ORAC assay) and metal chelating property. Furthermore, the stoichiometric ratio of Cu (ii)-5a and Cu(ii)-5g complexes were found by Job's method (0.5 : 1 for 5a and 0.8 : 1 for 5g). In silico ADMET profiling showed these derivatives to have drug like properties with very low toxicity effects in the pharmacokinetic study. Overall, these results displayed a multi-activity profile with promising Aß aggregation inhibition and antioxidation and metal chelation activity that could be helpful for developing new multifunctional agents against Alzheimer's disease.

Novel synthetic analogs of diallyl disulfide triggers cell cycle arrest and apoptosis via ROS generation in MIA PaCa-2 cells.

BACKGROUND: Diallyl disulfide (DADS), a principal organosulfur component of garlic, is known for its medicinal properties including anti-cancer activity. Prior studies have demonstrated that the compounds containing Diallyl disulfide moieties exhibited diverse therapeutic potential with promising biological activities. In the present study, we have investigated the in vitro anticancer activity of Diallyl disulfide derivatives (5a-5l and 7e-7m) against human cancer cell lines. METHODS: The effect of DADS analogs on different cancer cell lines was measured through MTT assay. Cell cycle progression, apoptosis, DNA fragmentation and levels of ROS were analyzed through FACS and confocal imaging. RESULTS: Bis[3-(3-fluorophenyl)prop-2-ene]disulfide (compound 5b) was the most potent compound among the tested DADS derivatives. FACS analysis revealed that increase in ROS generation by compound 5b was accompanied by cell cycle arrest in the G2/M phase and apoptosis in MIA PaCa-2 cells. Further, the apoptosis was confirmed by TUNEL assay. Western blot analysis showed that compound 5b induces G2/M phase arrest via ROS mediated DNA-damage, which in turn, induces phosphorylation of Chk1/Cdc25c/Cdc2 pathway. Furthermore, altered levels of ROS triggers intrinsic apoptotic cascade, as evidenced by dissipated mitochondrial membrane potential (ψ), decrease in Bcl-2/Bax ratio, cytochrome c release and cleavage of procaspase-3. Scavenging of ROS by antioxidant N-acetyl-cysteine (NAC) reversed the compound 5b induced augmented intracellular ROS levels and cell death. CONCLUSION: Taken together, the anti-proliferative effects of compound 5b were attributed to intracellular ROS accumulation, which in turn, triggers apoptosis by mediating DNA damage-induced G2/M phase arrest and evoking mitochondrial apoptotic pathway in MIA PaCa-2 cells.