Design and synthesis of new carbamates as inhibitors for fatty acid amide hydrolase and cholinesterases: Molecular dynamic, in vitro and in vivo studies

As anandamide (N-arachidonoylethanolamine, AEA) shows neuroprotective effects, the inhibition of its degradative enzyme, fatty acid amide hydrolase (FAAH) has been considered as a hopeful avenue for the treatment of neurodegenerative diseases, like Alzheimer's disease (AD). Memory loss, cognitive impairment and diminution of the cholinergic tone, due to the dying cholinergic neurons in the basal forebrain, are common hallmarks in patients with AD. By taking advantage of cholinesterase inhibitors (ChEIs), the degradation of acetylcholine (ACh) is decreased leading to enhanced cholinergic neurotransmission in the aforementioned region and ultimately improves the clinical condition of AD patients. In this work, new carbamates were designed as inhibitors of FAAH and cholinestrases (ChEs) (acetylcholinestrase (AChE), butyrylcholinestrase (BuChE)) inspired by the structure of the native substrates, structure of active sites and the SARs of the well-known inhibitors of these enzymes. All the designed compounds were synthesized using different reactions. All the target compounds were tested for their inhibitory activity against FAAH and ChEs by employing the Cayman assay kit and Elman method respectively. Generally, compounds possessing aminomethyl phenyl linker was more potent compared to their corresponding compounds possessing piperazinyl ethyl linker. The inhibitory potential of the compounds 3a-q extended from 0.83 ± 0.03 μM (3i) to ˃100 μM (3a) for FAAH, 0.39 ± 0.02 μM (3i) to 24% inhibition in 113 ± 4.8 μM (3b) for AChE, and 1.8 ± 3.2 μM (3i) to 23.2 ± 0.2 μM (3b) for BuChE. Compound 3i a heptyl carbamate analog possessing 2-oxo-1,2-dihydroquinolin ring and aminomethyl phenyl linker showed the most inhibitory activity against three enzymes. Also, compound 3i was investigated for memory improvement using the Morris water maze test in which the compound showed better memory improvement at 10 mg/kg compared to reference drug rivastigmine at 2.5 mg/kg. Molecular docking and molecular dynamic studies of compound 3i into the enzymes displayed the possible interactions of key residues of the active sites with compound 3i. Finally, kinetic study indicated that 3i inhibits AChE through the mixed- mode mechanism and non-competitive inhibition mechanism was revealed for BuChE.

Design, synthesis, and biological evaluation of novel 5,6,7-trimethoxy quinolines as potential anticancer agents and tubulin polymerization inhibitors

Objective(s):

Microtubules have key roles in essential cellular processes such as mitosis, cell motion, and intracellular organelle transport. Increasing interest has been given to tubulin binding compounds after the introduction of taxanes into clinical oncology. The object of this study was synthesis and biological evaluation of novel 5,6,7-trimethoxy quinolines as tubulin inhibitors.

Materials and Methods:

The cytotoxicity of the newly synthesized compounds was assessed against different human cancer cell lines including MCF-7, A2780, MCF-7/MX, A2780/RCIS, and normal cells. Compounds demonstrating the most antiproliferative activity, were chosen to examine their tubulin inhibition activity and their ability to arrest the cell cycle and induce apoptosis. Molecular docking studies and molecular dynamics simulation of compound 7e in the catalytic site of tubulin were performed.

Results:

Most of the synthesized quinolines showed moderate to significant cytotoxic activity against human cancer cells. Compounds 7e and 7f, possessing N-(4-benzoyl phenyl) and N-(4-phenoxy phenyl), respectively, exhibited the most antiproliferative activity more potent than the other compounds and exhibited similar antiproliferative activity on both resistant and parental cancer cells.

Conclusion:

Flow cytometry analysis of A2780, A2780/RCIS, MCF-7, and MCF-7/MX cancer cells treated with 7e and 7f exhibited that these compounds arrested the cell cycle (at the G2/M phase) and induced cellular apoptosis in A2780 cancer cells. These quinolines inhibited tubulin polymerization in a way resembling that of CA-4. Molecular dynamics simulation and molecular docking studies of compound 7e into the binding site of tubulin displayed the probable interactions of 7e with the binding site of tubulin.

Protective Effect of Cinnamaldehyde on METH-induced Neurotoxicity in PC12 Cells via Inhibition of Apoptotic Response and Oxidative Stress

Methamphetamine (METH) is a potent central nervous system (CNS) stimulant and frequently used illegal drugs. Repeated exposure to METH can induce degenerative changes in dopaminergic and serotonergic axons. There is no standard medical treatment for METH's neurotoxic effects. Cinnamaldehyde is an important compound of cinnamon and has activities against neurological disorders. The present study was designed to examine the neuroprotective effect of trans-cinnamaldehyde (TCA) on METH-induced cytotoxicity. PC12 cells were treated with METH (2.5 mM) 24 h after treated with different concentrations of TCA (3.75- 50 μM). The percentage of cell survival was evaluated by MTT assay and the following parameters were measured to detect apoptosis and oxidative stress responses: DNA fragmentation, ROS production and GSH content. Exposure to 2.5 mM METH decreased the cell viability and GSH levels, caused the generation of reactive oxygen species and ultimately induced apoptosis. Pretreatment with TCA at 3.125-25 μM significantly attenuated cell viability loss. TCA, especially at a concentration of 12.5 and 25 μM, decreased the apoptosis and ROS generation and increased the GSH level compared with the METH group. The findings of the present study suggested that TCA exerted a protective effect against METH-induced neurotoxicity through mechanisms related to antioxidant and anti-apoptosis. It is suggested that TCA may be useful for the prevention and treatment of harmful effects of METH on the brain.

Injectable In-Situ Forming Depot of Doxycycline Hyclate/α-Cyclodextrin Complex Using PLGA for Periodontitis Treatment: Preparation, Characterization, and In-Vitro Evaluation

BACKGROUND

Doxycycline (DOX) is used in treating a bacterial infection, especially for periodontitis treatment.

OBJECTIVE

To reduce irritation of DOX for subgingival administration and increase the chemical stability and against enzymatic, the complex of α-cyclodextrin with DOX was prepared and loaded into injectable in situ forming implant based on PLGA.

METHODS

FTIR, molecular docking studies, X-ray diffraction, and differential scanning calorimetry was performed to characterize the DOX/α-cyclodextrin complex. Finally, the in-vitro drug release and modeling, morphological properties, and cellular cytotoxic effects were also evaluated.

RESULTS

The stability of DOX was improved with complex than pure DOX. The main advantage of the complex is the almost complete release (96.31 ± 2.56 %) of the drug within 14 days of the implant, whereas in the formulation containing the pure DOX and the physical mixture the DOX with α-cyclodextrin release is reached to 70.18 ± 3.61 % and 77.03 ± 3.56 %, respectively. This trend is due to elevate of DOX stability in the DOX/ α-cyclodextrin complex form within PLGA implant that confirmed by the results of stability.

CONCLUSION

Our results were indicative that the formulation containing DOX/α-cyclodextrin complex was biocompatible and sustained-release with minimum initial burst release.

In-vitro Release Evaluation of Growth Hormone from an Injectable In-Situ Forming Gel Using PCL-PEG-PCL Thermosensitive Triblock

OBJECTIVE

An injectable long acting In-Situ Forming Gel (ISFG) of human Growth Hormone (hGH) was prepared by using triblock PCL-PEG-PCL (Mw 1500-1500-1500). Ring-Opening Polymerization (ROP) of triblock using microwave was applied.

METHODS

The BCA protein assay Kit was used to determine the concentration of hGH in the in-vitro release medium. Finally, Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) tests and Circular Dichroism (CD) spectrum were done to approve the stability of released hGH. The result of ROP demonstrated that the proportion of PCL to PEG accorded with the initial molar ratio of the monomers. The cross-section of the Surface Electron Microscopy (SEM) indicated the porous framework of the hydrogel could load the drug into its tridimensional matrixes structure. There is the low initial burst release of hGH from the supramolecular hydrogel.

RESULTS

The maximum in-vitro release of hGH was 71.2 % ± 1.5 that were due to hGH degrading after this time (21 days). The CD spectrum and SDS-PAGE results confirmed the stability of hGH during invitro release evaluation.

CONCLUSION

The results suggest that the sustained-release formulation using PCL-PEG-PCL can be applied to control the release of hGH.

Smac peptide and doxorubicin-encapsulated nanoparticles: design, preparation, computational molecular approach and in vitro studies on cancer cells

The N-terminal sequence of the Smac (second-mitochondria derived activator) protein is known to be involved in binding to the BIR3 (Baculovirus IAP repeat) domain of the IAPs (inhibitors of apoptosis proteins), and antagonized their function. Short peptides derived from N-terminal residues of Smac have shown to sensitize cancer cells to chemotherapeutic agents. In this regard, small library including 6-mer peptides were designed using docking to the BIR3 domain of cIAP1 in silico. Molecular dynamics simulation studies were also done on top-scored hits (SmacAQ, SmacIQ) using Desmond 2017-2 for 150 ns simulation time. These two peptides were conveniently synthesized using solid phase peptide synthesis on Fmoc-Gln (Trt)-Wang resin. Furthermore, we encapsulated DOX (doxorubicin) and synthesized peptides in PLGA: PLGA-PEG (9:1) NPs (nanoparticles) followed by MD (molecular dynamic) studies to understand the NP structure and the interactions between either DOX or peptide with polymeric nanoparticles during 100 ns simulation. Finally, the cytotoxic activity of these peptides in combination with DOX against two cancer cell lines including MCF7 and C26 were investigated. As a result, we found that DOX or peptide-loaded NPs had stable structure during the simulation. MD simulation also showed that alanine at N-terminal of Smac could be replaced with isoleucine without alternation of biological activity which was in agreement with in vitro experiments. Moreover, NPs-SmacIQ and NPs-SmacAQ significantly enhanced the cytotoxicity effect of NPs-DOX in vitro (p < 0.001).Communicated by Ramaswamy H. Sarma.

Combination therapy using Smac peptide and doxorubicin-encapsulated MUC 1-targeted polymeric nanoparticles to sensitize cancer cells to chemotherapy: An in vitro and in vivo study

Targeting inhibitors of apoptosis proteins (IAPs) family comprising high level expression in many cancer cells, could sensitize tumor cells to conventional chemotherapies. In the present study, we designed both doxorubicin and SmacN6 (an antagonist of the IAPs) encapsulated polymeric nanoparticles (NPs) and investigated their synergistic effect of combination therapy in vitro and in vivo. According to the results, NPs-SmacN6 significantly enhanced the cytotoxicity effect of NPs-DOX and reduced its IC₅₀ in MCF-7, 4T1 and C26 cancer cells. Western blot analysis confirmed mechanism of cell apoptosis via caspase activation through intrinsic and also extrinsic pathways. Moreover, 5TR1 aptamer-modified NPs could effectively deliver DOXor SmacN6 to C26 cancer cells (MUC1 positive) in comparison with the non-targeted one (p < 0.001). However, they could not be efficiently internalized into CHO cells (MUC1 negative), showing less cytotoxicity in this cell line. In vivo experiments in BALB/c mice bearing C26 tumor indicated that Apt-NPs-DOX in combination with Apt-NPs-SmacN6 had significant tumor growth inhibition in comparison with mice receiving either free DOX or Apt-NPs-DOX with p < 0.0001 and p < 0.05, respectively. Our results revealed that combination therapy of DOX and SmacN6 via Apt-modified nanoparticles can lead to improvement of therapeutic index of DOX in MUC1 positive cancer cells.

Potential inhibitory effect of lycopene on prostate cancer

Studying prostate cancer is important due to its high annual incidences and mortality rates in the world. Although prostate cancer mortality rates are reduced using new therapy, complicated routes and side effects of these current drugs require a daily available treatment for prevention. Lycopene is a natural, prominent, and effective product which has a high value in diet. The anti-cancer effect, non-toxicity, safety and preventive or therapeutic roles of lycopene have been investigated in several studies. In the current review, we have collected information about the anti-cancer, anti-progressive and apoptotic effects of lycopene on prostate cancer. This article is a summary of the most important original and review articles on lycopene and its anticancer effects that are systematically categorized and presents information about the molecular structure, different sources, biological functions, and its in-vivo and in-vitro effects of lycopene on variety of cancerous and normal cells. The clinical studies provide a clear image for continuous use of this adjunctive dietary for different type of cancers, especially prostate cancer in men. In addition, this article discusses the various molecular pathways activated by lycopene that eventually prevent or suppress cancer. Lycopene has been found to effectively suppress the progression and proliferation, arrest in-cell cycle, and induce apoptosis of prostate cancer cells in both in-vivo and in-vitro conditions. Additionally, lycopene showed that it could modulate the signaling pathways and their protein for the treatment or prevention of prostate cancer.

Design, synthesis and biological evaluation of novel 5,6,7-trimethoxy-N-aryl-2-styrylquinolin-4-amines as potential anticancer agents and tubulin polymerization inhibitors

A new series of styrylquinolines was designed and synthesized as anticancer agents and tubulin polymerization inhibitors. The in vitro anticancer activity of the synthesized quinolines was evaluated against four human cancer cell lines including A-2780 (human ovarian carcinoma), A-2780/RCIS (cisplatin resistant human ovarian carcinoma), MCF-7 (human breast cancer cells), MCF-7/MX (mitoxantrone resistant human breast cancer cells) and normal Huvec cells. Generally, among the forty-eight newly synthesized quinolines, compounds possessing N-trimethoxy phenyl showed stronger cytotoxic activity with IC₅₀ values ranging from 0.38 to 5.01 μM against all four cancer cell lines. Compounds 9VII-c and 9IV-c showed significant cytotoxic activity on A-2780 cancer cells, stronger than the other compounds and comparable to reference drug CA-4. Compound 9IV-c possessing 3,4-dimethoxystyryl and N-trimethoxy phenyl groups demonstrated potent cytotoxic effects with IC₅₀ values ranging from 0.5 to 1.66 µM on resistant cancer cells as well as their parental cells. Annexin V binding staining assay in A-2780 and MCF-7/MX cancer cells, revealed that compound 9IV-c induced early and late apoptosis. Compounds 9IV-c and 9VII-b, inhibited tubulin polymerization similar to CA4. Finally, molecular docking studies of 9IV-c and 9VII-b into the colchicine-binding site of tubulin displayed the possible interactions of these compounds with tubulin.

Statins and C-reactive protein: in silico evidence on direct interaction

INTRODUCTION

Statins are known to lower CRP, and this reduction has been suggested to contribute to the established efficacy of these drugs in reducing cardiovascular events and outcomes. However, the exact mechanism underlying the CRP-lowering effect of statins remains elusive.

METHODS

In order to test the possibility of direct interaction, we performed an in silico study by testing the orientation of the respective ligands (statins) and phosphorylcholine (the standard ligand of CRP) in the CRP active site using Molecular Operating Environment (MOE) software.

RESULTS

Docking experiments showed that all statins could directly interact with CRP. Among statins, rosuvastatin had the strongest interaction with CRP (pKi = 16.14), followed by fluvastatin (pKi = 15.58), pitavastatin (pKi = 15.26), atorvastatin (pKi = 14.68), pravastatin (pKi = 13.95), simvastatin (pKi = 7.98) and lovastatin (pKi = 7.10). According to the above-mentioned results, rosuvastatin, fluvastatin, pitavastatin and atorvastatin were found to have stronger binding to CRP compared with the standard ligand phosphocholine (pKi = 14.55).

CONCLUSIONS

This finding suggests a new mechanism of interaction between statins and CRP that could be independent of the putative cholesterol-lowering activity of statins.

Preparation, in vitro and in vivo evaluation of PLGA/Chitosan based nano-complex as a novel insulin delivery formulation

The smart self-regulated drug delivery systems for insulin administration are desirable to achieve glycemic control, and decrease the long-term micro- and macro vascular complications. In this study, we developed an injectable nano-complex formulation for closed-loop insulin delivery after subcutaneous administration and release of insulin in response to increased blood glucose levels. The nano-complex was prepared by mixing oppositely charged chitosan and PLGA nanoparticles. PLGA nanoparticles were prepared using double-emulsion solvent diffusion method, and were loaded with glucose oxidase (GOx) and catalase (CAT) enzymes. These negatively charged particles decrease micro-environmental pH, by gluconic acid production in the glucose molecules presence. Positively charged chitosan nanoparticles were prepared using ionic gelation method, and were loaded with insulin. These nanoparticles (NPs) released insulin by dissociation in acidic pH caused by the GOx activity. Following in vitro studies, in vivo evaluation of nano-complex formulations in streptozocin induced diabetic rats showed significant glycemic regulation up to 98 h after subcutaneous administration.

Design, Synthesis, and Biological Evaluation of New Azole Derivatives as Potent Aromatase Inhibitors with Potential Effects against Breast Cancer

PURPOSE

Some aromatase inhibitors are FDA-approved agents as first-line therapy in the treatment of endocrine-responsive breast cancer. In this study, we aimed to develop new azole derivatives with higher specificity and potency.

METHODS

New aromatase inhibitors were designed by Molecular Operating Environment (MOE) software and synthesized in a one-step SN2 reaction. These compounds were characterized by melting point, 1H- and 13CNMR, elemental analysis and mass spectra. The in vitro and in vivo aromatase inhibition of these compounds was evaluated using the Estrone ELISA assay, and by measuring the inhibition of androstenedione-induced uterine hypertrophy. The selectivity of aromatase inhibition was investigated by the inhibition of ACTH stimulation on the plasma concentrations of aldosterone and cortisol.

RESULTS

Docking simulations showed that four new azole derivatives could efficiently interact with enzyme active sites. The in vitro aromatase-inhibition assay showed that the compounds 1,3,5-tris(imidazol-1- ylmethyl)benzene (3b) and 1,3-Bis(imidazole-1- ylmethyl) benzene (3d) effectively inhibited aromatase, with IC50 values of 0.2 nM and 6.8 nM, respectively; these values were similar to known aromatase inhibitor letrozole (IC50 0.3 nM). The in vivo aromatase-inhibitory potency of compound 3b was similar to letrozole, although compound 3b acted more selectively.

CONCLUSION

This report introduced a new compound that can be considered as a new lead for further investigation to explore more-potent and more-selective aromatase inhibitors.

The natural phenolic compounds as modulators of NADPH oxidases in hypertension

BACKGROUND

Hypertension is a major public health problem worldwide. It is an important risk factor for other cardiovascular diseases such as coronary artery disease, stroke, heart failure, atrial fibrillation, peripheral vascular disease, chronic kidney disease, and atherosclerosis.

PURPOSE

There is strong evidence that excess ROS-derived NADPH oxidase (NOX) is an important agent in hypertension. It augments blood pressure in the presence of other pro-hypertensive factors such as angiotensin II (Ang II), an important and potent regulator of cardiovascular NADPH oxidase, activates NOX via AT1 receptors. NADPH oxidase, a multi-subunit complex enzyme, is considered as a key source of ROS production in the vasculature. The activation of this enzyme is needed for assembling Rac-1, p^40phox, p^47phox and p^67phox subunits. Since, hypertensive patients need to control blood pressure for their entire life and because drugs and other chemicals often induce adverse effects, the use of natural phenolic compounds which are less toxic and potentially beneficial may be good avenues of addition research in our understand of the underlying mechanism involved in hypertension. This review focused on several natural phenolic compounds as berberine, thymoquinone, catechin, celastrol, apocynin, resveratrol, curcumin, hesperidine and G-hesperidine, and quercetin which are NOX inhibitors. In addition, structure activity relationship of these compounds eventually as the most inhibitors was discussed.

METHODS

This comprehensive review is based on pertinent papers by a selective search using relevant keywords that was collected using online search engines and databases such as ScienceDirect, Scopus and PubMed. The literature mainly focusing on natural products with therapeutic efficacies against hypertension via experimental models both in vitro and in vivo was identified.

RESULTS

It has been observed that these natural compounds prevent NADPH oxidase expression and ROS production while increasing NO bioavailability. It have been reported that they improve hypertension due to formation of a stable radical with ROS-derived NADPH oxidase and preventing the assembly of NOX subunites.

CONCLUSION

It is clear that natural phenolic compounds have some potential inhibitory effect on NADPH oxidase activity. In comparison to other phenolic plant compounds, the structural variability of the flavonoids should off different impacts on oxidative stress in hypertension including inhibition of nadph oxidase and direct scavenging of free radicals.