Identification of the Candidate mGlu2 Allosteric Modulator THRX-195518 through In Silico Method and Evaluation of Its Neuroprotective Potential against Glutamate-Induced Neurotoxicity in SH-SY5Y Cell Line

Glutamate (Glu) toxicity has been an important research topic in toxicology and neuroscience studies. In vitro and in vivo studies have shown that Group II metabotropic Glu2 (mGlu2) activators have cell viability effects. This study aims to determine a candidate ligand with high mGlu2 allosteric region activity among cytotoxicity-safe molecules using the in silico positioning method and to evaluate its cell viability effect in vitro. We investigated the candidate molecule's cell viability effect on the SH-SY5Y human neuroblastoma cell line by MTT analysis. In the study, LY 379268 (agonist) and JNJ-46281222 (positive allosteric modulator; PAM) were used as control reference molecules. Drug bank screening yielded THRX-195518 (docking score being -12.4 kcal/mol) as a potential novel drug candidate that has a high docking score and has not been mentioned in the literature so far. The orthosteric agonist LY 379268 exhibited a robust protective effect in our study. Additionally, our findings demonstrate that JNJ-46281222 and THRX-195518, identified as activating the mGlu2 allosteric region through in silico methods, preserve cell viability against Glu toxicity. Therefore, our study not only emphasizes the positive effects of this compound on cell viability against Glu toxicity but also sheds light on the potential of THRX-195518, acting as a mGlu2 PAM, based on in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) data, as a candidate drug molecule. These findings underscore the potential utility of THRX-195518 against both neurotoxicity and Central Nervous System (CNS) disorders, providing valuable insights.

Queuine as a potential multi-target drug for alzheimer's disease: insights from protein dynamics

Alzheimer's disease (AD) is a neurodegenerative disorder with a complex pathogenesis. One promising approach to treating AD is simultaneously targeting multiple aspects of the disease using a multi-target drug (MTD). In this study, multi-target drug (MTD) potential of the nutraceutical molecule Queuine was explored using molecular docking and molecular dynamics (MD) simulations with five different protein targets engaged in AD: AChE, beta-site amyloid precursor protein cleaving enzyme-1 (BACE-1), N-methyl-D-aspartate receptor (NMDAR), monoamine oxidase A (MAO-A), and Synapsin III. Queuine revealed significant binding affinities, the docking scores being -10.1, -5.97, -5.63, -8.40, and -10.56 kcal/mol for AChE, BACE-1, NMDAR, MAO-A, and Synapsin III, respectively. MD simulations showed that Queuine formed stable complexes and preserved its stability throughout the simulation, the backbone fluctuations remaining within 2.5 Å specifically in the case of the BACE-1. Elastic network model simulations and principal component analysis were carried out to illustrate the dynamics of the protein systems. Significant hinge-bending and twisting-type motions that may be relevant to function were observed around the dimerization interfaces or binding sites. Structural clustering based on PCA analysis and cross-correlation maps demonstrated that Queuine binding altered the protein dynamics more drastically in the case of highly mobile proteins NMDAR and MAO-A. We propose that the neuroprotective effect of Queuine may stem from its prominent inhibitory action on enzymes BACE-1 and AChE. Our results suggest that Queuine may serve as a promising MTD candidate for the treatment of AD.Communicated by Ramaswamy H. Sarma.

The effect of different suture materials on the safety of colon anastomosis in an experimental peritonitis model

BACKGROUND

The aim of this experimental study was to compare the safety of different suture materials in a left colonic anastomosis in the presence of peritonitis.

MATERIALS AND METHODS

Twenty-one male Wistar albino rats were randomly divided into three groups. First, left colonic injuries were created in all groups for the peritonitis model. After 24 hours, coated polyglactin 910 and silk suture were used in Group I rats, polydioxanone and silk suture were used in Group II rats, and coated polyglactin 910 plus antibacterial suture and silk suture were used in Group III rats during colonic anastomosis. Tissue hydroxyproline, anastomotic bursting pressure, and histopathologic findings on the anastomosis line were evaluated on the 10th postoperative day by performing a relaparatomy.

RESULTS

The mean bursting pressure values were 198 ± 11.37, 220 ± 17.7, and 244 ± 9.52 in Groups I, II, and III, respectively (Group I vs. II, p < 0.035; I vs III, p < 0.002; and II vs III, p < 0.021). The mean hydroxyproline levels were 1.21 ± 0.58, 1.47 ± 0.44, and 2.11 ± 0.32 in Groups I, II, and III, respectively (Group I vs II, p < 0.338; I vs III, p < 0.011; and II vs III, p < 0.025). When histopathologic findings of the groups were compared, the healing score of the intestinal tissue was higher in Group III than in Group I (p < 0.015), whereas there were no statistically significant differences among Groups I vs II and II vs III (p < 0.081 and p < 0.095, respectively).

CONCLUSION

Antibacterial suture usage increased anastomosis safety in the presence of peritonitis in resection and primary anastomosis.

Proposing novel natural compounds against Alzheimer's disease targeting acetylcholinesterase

Alzheimer's disease (AD) is a neurodegenerative disorder considered as a global public health threat influencing many people. Despite the concerning rise in the affected population, there is still a shortage of potent and safe therapeutic agents. The aim of this research is to discover novel natural source molecules with high therapeutic effects, stability and less toxicity for the treatment of AD, specifically targeting acetylcholinesterase (AChE). This research can be divided into two steps: in silico search for molecules by systematic simulations and in vitro experimental validations. We identified five leading compounds, namely Queuine, Etoperidone, Thiamine, Ademetionine and Tetrahydrofolic acid by screening natural molecule database, conducting molecular docking and druggability evaluations. Stability of the complexes were investigated by Molecular Dynamics simulations and free energy calculations were conducted by Molecular Mechanics Generalized Born Surface Area method. All five complexes were stable within the binding catalytic site (CAS) of AChE, with the exception of Queuine which remains stable on the peripheral site (PAS). On the other hand Etoperidone both interacts with CAS and PAS sites showing dual binding properties. Binding free energy values of Queuine and Etoperidone were -71.9 and -91.0 kcal/mol respectively, being comparable to control molecules Galantamine (-71.3 kcal/mol) and Donepezil (-80.9 kcal/mol). Computational results were validated through in vitro experiments using the SH-SY5Y(neuroblastoma) cell line with Real Time Cell Analysis (RTCA) and cell viability assays. The results showed that the selected doses were effective with half inhibitory concentrations estimated to be: Queuine (IC50 = 70,90 μM), Etoperidone (IC50 = 712,80 μM), Thiamine (IC50 = 18780,34 μM), Galantamine (IC50 = 556,01 μM) and Donepezil (IC50 = 222,23 μM), respectively. The promising results for these molecules suggest the development of the next step in vivo animal testing and provide hope for natural therapeutic aids in the treatment of AD.