In Silico design of AVP (4–5) peptide and synthesis, characterization and in vitro activity of chitosan nanoparticles

Abstract

Background Arginine-vasopressin (AVP) is a neuropeptide and provides learning and memory modulation. The AVP (4-5) dipeptide corresponds to the N-terminal fragment of the major vasopressin metabolite AVP (4-9), has a neuroprotective effect and used in the treatment of Alzheimer's and Parkinson's disease. Methods The main objective of the present study is to evaluate the molecular mechanism of AVP (4-5) dipeptide and to develop and synthesize chitosan nanoparticle formulation using modified version of ionic gelation method, to increase drug effectiveness. For peptide loaded chitosan nanoparticles, the synthesized experiment medium was simulated for the first time by molecular dynamics method and used to determine the stability of the peptide, and the binding mechanism to protein (HSP70) was also investigated by molecular docking calculations. A potential pharmacologically features of the peptide was also characterized by ADME (Absorption, Distribution, Metabolism and Excretion) analysis. The characterization, in vitro release study, encapsulation efficiency and loading capacity of the peptide loaded chitosan nanoparticles (CS NPs) were performed by Dynamic Light Scattering (DLS), UV-vis absorption (UV), Scanning Electron Microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy techniques. Additionally, in vitro cytotoxicity of the peptide on human neuroblastoma cells (SH-SY5Y) was examined with XTT assay and the statistical analysis was evaluated. Results The results showed that; hydrodynamic size, zeta potential and polydispersity index (PdI) of the peptide-loaded CS NPs were 167.6 nm, +13.2 mV, and 0.211, respectively. In vitro release study of the peptide-loaded CS NPs showed that 17.23% of the AVP (4-5)-NH2 peptide was released in the first day, while 61.13% of AVP (4-5)-NH2 peptide was released in the end of the 10th day. The encapsulation efficiency and loading capacity were 99% and 10%, respectively. According to the obtained results from XTT assay, toxicity on SHSY-5Y cells in the concentration from 0.01 μg/μL to 30 μg/μL were evaluated and no toxicity was observed. Also, neuroprotective effect was showed against H 2 O 2 treatment. Conclusion The experimental medium of peptide-loaded chitosan nanoparticles was created for the first time with in silico system and the stability of the peptide in this medium was carried out by molecular dynamics studies. The binding sites of the peptide with the HSP70 protein were determined by molecular docking analysis. The size and morphology of the prepared NPs capable of crossing the blood-brain barrier (BBB) were monitored using DLS and SEM analyses, and the encapsulation efficiency and loading capacity were successfully performed with UV Analysis. In vitro release studies and in vitro cytotoxicity analysis on SHSY-5Y cell lines of the peptide were conducted for the first time.

Vasopressin as a Possible Link between Sleep-Disturbances and Memory Problems

“…However, it might be connected to hyponatremia and not to the AVP level increase itself. In line with these contradictory results in a study using male Sprague-Dawley rats, intraperitoneal administration of a V1aR antagonist prevented trauma-induced cognitive decline detected by a Barnes maze test for assessing hippocampus-dependent spatial memory [ 147 ].…”

New anti-viral drugs for the treatment of COVID-19 instead of favipiravir

“…Molecules are required to be between the Solute Dipole Moment of 1.0-12.5 Debye. Many other parameters are indicated as follows -Solute Total SASA: total solvent-accessible surface area; Solute Carbom Pi SASA: Van der Waals surface area of polar nitrogen and oxygen atoms and carbonyl carbon atoms; QPlogPo/w: Predicted octanol/water partition coefficient; QPlogS: Predicted aqueous solubility; log S: S in mol dm-3 is the concentration of the solute in a saturated solution that is in equilibrium with the crystalline solid; QPlogBB: brain/blood partition coefficient; QPlogKhsa: binding to human serum albumin; Apparent Caco-2 Permeability: Predicted apparent Caco-2 cell permeability (nm/s) where Caco-2 cells are a model for the gut-blood barrier; QP log BB for brain/blood: Predicted brain/blood partition coefficient for orally delivered drugs; Apparent MDCK Permeability: Predicted apparent MDCK cell permeability (nm/s) where MDCK cells are considered to be a good mimic for the blood-brain barrier; % Human Oral Absorption in Gl: Human oral absorption on a 0-100% scale (>80% is high, <25% is poor); Solute as Donor-Hydrogen Bonds: Predicted number of donor hydrogen bonds; Solute as Acceptor-Hydrogen: Predicted number of acceptor hydrogen bond; QP log p for X/Y: Predicted X/Y partition coefficient; IC50 value for the blockage of HERG K þ channels (acceptable range: above 25.0); Solute CdW Polar SA (PSA): total polar surface area (Acar et al, 2019;Bicak et al, 2019;Budama-Kilinc et al, 2018;Ertas et al, 2019;Kecel-Gunduz et al, 2020;Menteşe et al, 2019;Mermer et al, 2019;Sari et al, 2019;Singh & Bast, 2014); Lipinski Rule of 5 Violations: Number of violations of Lipinski's rule of five where the rules are: mol_MW (molecular weight of the molecule) < 500; QPlogPo/w (predicted octanol/water partition coefficient) < 5; donorHB (hydrogenbond donor atoms) 5; accptHB (hydrogen-bond acceptor atoms)…”