Phytochemical profiling, in vitro biological activities, and in silico (molecular docking and absorption, distribution, metabolism, excretion, toxicity) studies of Polygonum cognatum Meissn.

Polygonum cognatum Meissn, a perennial herbaceous belonging to the Polygonaceae family, is an aromatic plant. High-performance liquid chromatography/diode array detector method was developed and validated for the phytochemical analysis of the plant. Also, various methods were used to investigate the antioxidant, antimicrobial, and cytotoxic activities of the methanolic extracts. Antioxidant activities were researched by 2,2'-diphenyl-1-picrylhydrazyl and cupric reducing antioxidant capacity methods. Among the tested standard microbial strains, Candida albicans was found to be more sensitive with a 24.60 ± 0.55 mm inhibition zone according to the diffusion tests. In the microdilution tests, the minimum inhibitory concentration and minimum bactericidal/fungicidal concentration values were 4.75 and ≥ 4.75 mg/mL, respectively, for all tested pathogens. Human colon carcinoma cells were used to investigate cytotoxicity by using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide analysis (IC50  = 2891 µg/mL for Plant A, IC50  = 3291 µg/mL for Plant B). Molecular docking and absorption, distribution, metabolism, excretion, and toxicity analysis were used to explain inhibition mechanisms of major phenolic compounds of plants against Tankyrase 1, Tankyrase 2 enzymes, and deoxyribonucleic acid gyrase subunit B and found compatible with experimental results.

Structural, spectroscopic, molecular docking, ADME, molecular dynamics studies of Val-Trp dipeptide.

Hypertension is a significant risk factor for various diseases, especially heart, brain, and kidney diseases. It is known that many peptides have the property of lowering blood pressure and determine as ACE inhibitors. The purpose of this study is to obtain information about the molecular structure of Val-Trp (L-valyl-L-tryptophan), which is one of the antihypertensive peptides, by molecular mechanical, quantum mechanical, and spectroscopic methods (FT-IR and Raman). Also, it is aimed to investigate the interactions of Val-Trp dipeptide with receptors related to hypertension and to determine the pharmacokinetic profile due to the potential of the peptide to be a drug candidate. The peptide structure was optimized by DFT/B3LYP/6-311++G(d,p) basis set, then vibrational wavenumbers, molecular electrostatic potential (MEP), HOMO-LUMO (highest occupied molecular orbital- lowest unoccupied molecular orbital), NBO (natural bond orbital) analyzes were performed. The assignment of fundamental theoretical vibration wavenumbers was carried out with potential energy distribution analysis (PED). After the structural analyzes of the peptide were performed, the interactions of the peptide with Angiotensin-converting enzyme (ACE), Angiotensin II Receptor Type 1 (AT1R) and Renin were investigated by molecular docking study. Then, the molecular dynamic (MD) simulation of the peptide-ACE complex with the best binding affinity in the molecular docking studies was carried out for 50 ns. ADME (absorption, distribution, metabolism, and excretion) analysis of Val-Trp dipeptide was performed. In support of the studies carried out, enlightening information about the feasibility of the antihypertensive drug of Val-Trp dipeptide with the help of the ADME profile was presented to the literature.Communicated by Ramaswamy H. Sarma.

Molecular docking studies of YKT tripeptide and drug delivery system with poly(ε-caprolactone) nanoparticles.

Tyrosyllysylthreonine (YKT) is a peptide structure that contains three different amino acids in its structure and has anticancer properties. The main purpose of this study is to reveal the structural interactions of the peptide and to increase the efficiency of the peptide with nanoformulation. For these purposes, YKT-loaded poly(ε-caprolactone) (PCL) nanoparticles (NPs) were synthesized using the double-emission precipitation method and the obtained NPs were characterized with a Zeta Sizer, UV-Vis, Fourier transform infrared-attenuated total reflection spectrometers, scanning electron microscopy, and transmission electron microscopy. The in vitro release profile of the peptide-loaded PCL NPs was determined. In molecular modeling studies, PCL, PCL-polyvinyl alcohol (PVA), and PCL-PVA-YKT systems were simulated in an aqueous medium by molecular dynamics simulations, separately. The information about the interactions between the YKT tripeptide and the epidermal growth factor and androgen, estrogen, and progesterone receptors were obtained with the molecular docking study. Additionally, the ADME profile of YKT was determined as a result of each docking study. In conclusion, tripeptide-based nanodrug development studies of the YKT tripeptide are presented in this study.

Structural, spectroscopic, in silico, in vitro and DNA binding evaluations of tyrosyl-lysyl-threonine.

The main objective of the present study is to investigate the molecular structure and DNA binding interaction of the tyrosyl-lysyl-threonine (YKT) tripeptide, which has anticancer, antioxidant and analgesic properties, using various in silico (MD, QM, molecular docking), spectroscopic (UV, FT-IR, FTIR-ATR, Raman, gel electrophoresis) and in vitro (MCF-7 and HeLa cancer cell lines and BEAS-2B cell line) methods. The optimized geometry, vibrational wavenumbers, molecular electrostatic potential (MEP), natural bond orbital (NBO) and HOMO-LUMO (highest occupied molecular orbital- lowest unoccupied molecular orbital) calculations were carried out with Density Functional Theory (DFT) using B3LYP/6-311++G(d,p) basis set to indicate conformational, vibrational and intramolecular charge transfer characteristics. The assignment of all fundamental theoretical vibration wavenumbers was performed using potential energy distribution analysis (PED). DNA is a significant pharmacological target of drugs in several diseases such as cancer. For this reason, molecular docking calculation was used to elucidate the binding and interaction between YKT tripeptide and DNA at the atomic level. Also, the dynamic behaviors of YKT and DNA was examined using MD simulations. Besides, the interaction of YKT with DNA was experimentally examined by UV titration method and agarose gel electrophoresis method. Experimental results showed that YKT was intercalatively and electrostatically bound to CT-DNA (Calf thymus DNA) and cleavage pBR322 DNA in the presence of H2O2. The pharmacokinetic profile of YKT was also obtained. Cytotoxic effect of YKT was evaluated on MCF-7, HeLa and BEAS-2B cell lines. Hence, these studies about YKT tripeptide may pave the way for the development of various cancer drugs. Communicated by Ramaswamy H. Sarma.

New nanodrug design for cancer therapy: Its synthesis, formulation, in vitro and in silico evaluations.

The aim of this study was to develop a novel nanosize drug candidate for cancer therapy. For this purpose, (S)-methyl 2-[(7-hydroxy-2-oxo-4-phenyl-2H-chromen-8-yl)methyleneamino]-3-(1H-indol-3-yl)propanoate (ND3) was synthesized by the condensation reaction of 8-formyl-7-hydroxy-4-phenylcoumarin with l-tryptophan methyl ester. Its controlled release formulation was prepared and characterized by different spectroscopic and imaging methods. The cytotoxic effects of ND3 and its controlled release formulation were evaluated against MCF-7 and A549 cancer cell lines, and it was found that both of them have a toxic effect on cancer cells. For drug design and process development, the molecular docking analysis technique helps to clarify the effects of some DNA-targeted anticancer drugs to determine the interaction mechanisms of these drugs on DNA in a shorter time and at a lower cost. By using the molecular docking analysis and DNA binding assays, the interaction between the synthesized compound and DNA was elucidated and non-binding interactions were also determined. To predict the pharmacokinetics, and thereby accelerate drug discovery, the absorption, distribution, metabolism, excretion and toxicity values of the synthesized compound were determined by in silico methods.

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

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 H2O2 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. Grapical abstract.

In silico Analysis of Sulpiride, Synthesis, Characterization and In vitro Studies of its Nanoparticle for the Treatment of Schizophrenia.

BACKGROUND: Sulpiride, which has selective dopaminergic blocking activity, is a substituted benzamide antipsychotic drug playing a prominent role in the treatment of schizophrenia, which more selective and primarily blocks dopamine D2 and D3 receptor. OBJECTIVE: This study has two main objectives, firstly; the molecular modeling studies (MD and Docking, ADME) were conducted to define the molecular profile of sulpiride and sulpiridereceptor interactions, another to synthesize polymeric nanoparticles with chitosan, having the advantage of slow/controlled drug release, to improve drug solubility and stability, to enhance utility and reduce toxicity. METHODS: Molecular dynamic simulation was carried out to determine the conformational change and stability (in water) of the drug and the binding profile of D3 dopamine receptor was determined by molecular docking calculations. The pharmacological properties of the drug were revealed by ADME analysis. The ionic gelation method was used to prepare sulpiride loaded chitosan nanoparticles (CS NPs). The Dynamic Light Scattering (DLS), UV-vis absorption (UV), Scanning Electron Microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy techniques were carried out to characterize the nanoparticles. In vitro cell cytotoxicity experiments examined with MTT assay on mouse fibroblast (L929), human neuroblastoma (SH-SY5Y) and glioblastoma cells (U-87). The statistical evaluations were produced by ANOVA. RESULTS: The residues (ASP-119, PHE-417) of D3 receptor provided a stable docking with the drug, and the important pharmacological values (blood brain barrier, Caco-2 permeability and human oral absorption) were also determined. The average particle size, PdI and zeta potential value of sulpiride- loaded chitosan NPs having a spherical morphology were calculated as 96.93 nm, 0.202 and +7.91 mV. The NPs with 92.8% encapsulation and 28% loading efficiency were found as a slow release profile with 38.49% at the end of the 10th day. Due to the formation of encapsulation, the prominent shifted wave numbers for C-O, S-O, S-N stretching, S-N-H bending of Sulpiride were also identified. Mitochondrial activity of U87, SHSY-5Y and L929 cell line were assayed and evaluated using the SPSS program. CONCLUSION: To provide more efficient use of Sulpiride having a low bioavailability of the gastrointestinal tract, the nanoparticle formulation with high solubility and bioavailability was designed and synthesized for the first time in this study for the treatment of schizophrenia. In addition to all pharmacological properties of drug, the dopamine blocking activity was also revealed. The toxic effect on different cell lines have also been interpreted.

Papain Loaded Poly(ε-Caprolactone) Nanoparticles: In-silico and In-Vitro Studies.

Papain is a protease enzyme with therapeutic properties that are very valuable for medical applications. Poly(ε-caprolactone) (PCL) is an ideal polymeric carrier for controlled drug delivery systems due to its low biodegradability and its high biocompatibility. In this study, the three-dimensional structure and action mechanism of papain were investigated by in vitro and in silico experiments using molecular dynamics (MD) and molecular docking methods to elucidate biological functions. The results showed that the size of papain-loaded PCL nanoparticles (NPs) and the polydispersity index (PDI) of the NPs were 242.9 nm and 0.074, respectively. The encapsulation efficiency and loading efficiency were 80.4 and 27.2%, respectively. Human embryonic kidney cells (HEK-293) were used for determining the cytotoxicity of papain-loaded PCL and PCL nanoparticles. The in vitro cell culture showed that nanoparticles are not toxic at low concentrations, while toxicity slightly increases at high concentrations. In silico studies, which were carried out with MD simulations and ADME analysis showed that the strong hydrogen bonds between the ligand and the papain provide stability and indicate the regions in which the interactions occur.

Novel NAC-loaded poly(lactide-co-glycolide acid) nanoparticles for cataract treatment: preparation, characterization, evaluation of structure, cytotoxicity, and molecular docking studies.

BACKGROUND: N-acetylcarnosine (NAC), a dipeptide with powerful antioxidant properties that is extensively used as a pharmaceutical prodrug for the treatment of cataract and acute gastric disease, was investigated by molecular dynamics with the GROMACS program in order to understand the solvent effect on peptide conformation of the peptide molecule used as a component of a drug and which presents substantial information on where drug molecules bind and how they exert their effects. Besides, molecular docking simulation was performed by using the AutoDock Vina program which identify the kind of interaction between the drug and proteins. A delivery system based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with NAC (NAC-PLGA-NPs) for the treatment of cataract was prepared for the first time in this study in order to enhance drug bioavailability and biocompatibility. The objective of this work was to prepare and evaluate the structural formulation, characterization, and cytotoxicity studies of NAC-loaded NPs based on PLGA for cataract treatment. METHODS: PLGA and NAC-loaded PLGA NPs were prepared using the double emulsion (w/o/w) method, and characterizations of the NPs were carried out with UV-Vis spectrometer to determine drug concentration, the Zeta-sizer system to analyze size and zeta potential, FTIR spectrometer to determine the incorporation of drug and PLGA, and TEM analysis for morphological evaluation. RESULTS: NAC-loaded PLGA NPs were successfully obtained according to UV-Vis and FTIR spectroscopy, Zeta-sizer system. And it was clearly observed from the TEM analysis that the peptide-loaded NPs had spherical and non-aggregated morphology. Also, the NPs had low toxicity at lower concentrations, and toxicity was augmented by increasing the concentration of the drug. DISCUSSION: The NAC molecule, which has been investigated as a drug molecule due to its antioxidant and oxidative stress-reducing properties, especially in cataract treatment, was encapsulated with a PLGA polymer in order to increase drug bioavailability. This study may contribute to the design of drugs for cataract treatment with better reactivity and stability.

Computational design of Phe-Tyr dipeptide and preparation, characterization, cytotoxicity studies of Phe-Tyr dipeptide loaded PLGA nanoparticles for the treatment of hypertension.

Phe-Tyr dipeptide which was investigated in Wakame food with greatest ACE-inhibitory activity is used as a pharmaceutical drug for the treatment of hypertension, cardiovascular diseases, and diabetic nephropathy. To improve the bioavailability of Phe-Tyr, a delivery system based on poly (lactic-co-glycolic acid) (PLGA) nanoparticles loaded with Phe-Tyr (Phe-Tyr-PLGA NPs) for treating hypertension and cardiovascular diseases was prepared in this study. In the experiments, poly(lactic-co-glycolic acid) (PLGA) and Phe-Tyr dipeptide-loaded PLGA nanoparticles were prepared using the double emulsion (w/o/w) method. The characterizations of the nanoparticles were performed with a UV-vis spectrometer, the Zeta-sizer system, and FTIR spectrometer. The optimum size of the Phe-Tyr dipeptide-loaded PLGA nanoparticle was obtained with a 213.8 nm average particle size, and a 0.061 polydispersity index, -19.5 mV zeta potential, 34% of loaded and 90.09% of encapsulation efficiency. From TEM analysis, it was clearly seen that the dipeptide loaded nanoparticles had the spherical and non-aggregated morphology and Phe-Tyr dipeptide loaded-PLGA nanoparticles were obtained successfully. Cell toxicity of nanoparticles at different concentrations was assayed with XTT methods on L929 fibroblast cells. This study determined that the nanoparticles have low toxicity at lower concentration and toxicity augmented with increasing concentration of dipeptide. To analyze the effect of solvents on structure of Phe-Tyr, Molecular dynamics simulation was performed with GROMACS program and molecular orbital calculations were carried out to obtain structural and electronic properties of dipeptide. Moreover, molecular docking calculations were also employed to model and predict protein-drug interactions.