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.

A coarse-grain MD (molecular dynamic) simulation of PCL-PEG and PLA-PEG aggregation as a computational model for prediction of the drug-loading efficacy of doxorubicin

Formulating a hydrophobic drug that is water-soluble is a pharmaceutical challenge. One way is to incorporate the drug in an amphiphilic micelle composed from an aggregation of block copolymers. Design of a good nano-micelle requires many trial-and-error attempts. In this article, we developed a computational model based on a coarse-grained molecular dynamic (MD) simulation and correlated outputs with previous studies. A good correlation shows that this model reliably simulates poly-lactic acid-poly-ethylene glycol (PLA-PEG) and poly-caprolactone (PCL)-PEG aggregation in water with and without the presence of doxorubicin. Communicated by Ramaswamy H. Sarma.

Docetaxel-Loaded Mixed Micelles and Polymersomes Composed of Poly (caprolactone)-Poly (ethylene glycol) (PEG-PCL) and Poly (lactic acid)-Poly (ethylene glycol) (PEG-PLA): Preparation and In-vitro Characterization

Microwave irradiation was used to synthesize poly (caprolactone)-poly (ethylene glycol) (PEG-PCL) and poly (lactic acid)-poly (ethylene glycol) (PEG-PLA) copolymers that are composed of biodegradable polymers including PEG, PLA, and PCL. These copolymers were used for loading docetaxel in nanoparticles. Single emulsion-solvent evaporation technique was applied for preparing the PEG-PLA and PEG-PCL mixed nanoparticles (micelles and polymersomes) with different proportions, including 0:1, 1:1, 3:1, 1:3, and 1:0. The unimodal gel permeation chromatography curve showed low polydispersity of the di-block copolymers. The in-vitro drug release curves of formulations were compared. Micelles and polymersomes of 75% PEG-PCL and 25% PEG-PLA (P5 and M5) have the lowest burst release (5%) at the same period compared to the other copolymers. The dynamic light scattering and TEM results clarified that the size and shape of the formulations are uniform. The cytotoxicity effect of P5 and M5 was evaluated in different cell lines. The best one was found to P5 with half maximal inhibitory concentration (IC₅₀) between 1.48-11.79 µg/mL. The pro-apoptotic effect of P5 was confirmed with flow cytometry study. These mixed micelles (M5) and polymersomes (P5) was found to be superior formulations than non-mixed ones.

Structural and functional aspects of P-glycoprotein and its inhibitors

P-glycoprotein (P-gp) is a member of ATP-binding cassette (ABC) superfamily which extrudes chemotherapeutic agents out of the cell. Suppression of this efflux activity has been the subject of numerous attempts to develop P-gp inhibitors. The aim of this review is to present up-to-date information on the structural and functional aspects of P-gp and its known inhibitors. The data presented also provide some information on drug discovery approaches for candidate P-gp inhibitors. Nucleotide-binding domains (NBDs) and drug-binding domains (DBDs) have been extensively studied to gain more information about P-gp inhibition and it looks that the ATPase activity of this pump has been the most attractive target for designing inhibitors. Hydrophobic and π-π (aromatic) interactions between P-gp binding domains and inhibitors are dominant intermolecular forces that have been reported in many studies using different methods. Many synthetic and natural products have been found to possess inhibitory or modulatory effects on drug transporter proteins. Log P value is an important factor in studying these inhibitors and has a crucial role on absorption, distribution, metabolism, and excretion (ADME) properties of candidate P-gp inhibitors.

A GWAS meta-analysis from 5 population-based cohorts implicates ion channel genes in the pathogenesis of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) shows genetic predisposition, however, large-scale, powered gene mapping studies are lacking. We sought to exploit existing genetic (genotype) and epidemiological (questionnaire) data from a series of population-based cohorts for IBS genome-wide association studies (GWAS) and their meta-analysis.

METHODS

Based on questionnaire data compatible with Rome III Criteria, we identified a total of 1335 IBS cases and 9768 asymptomatic individuals from 5 independent European genotyped cohorts. Individual GWAS were carried out with sex-adjusted logistic regression under an additive model, followed by meta-analysis using the inverse variance method. Functional annotation of significant results was obtained via a computational pipeline exploiting ontology and interaction networks, and tissue-specific and gene set enrichment analyses.

KEY RESULTS

Suggestive GWAS signals (P ≤ 5.0 × 10^-6 ) were detected for 7 genomic regions, harboring 64 gene candidates to affect IBS risk via functional or expression changes. Functional annotation of this gene set convincingly (best FDR-corrected P = 3.1 × 10^-10 ) highlighted regulation of ion channel activity as the most plausible pathway affecting IBS risk.

CONCLUSION & INFERENCES

Our results confirm the feasibility of population-based studies for gene-discovery efforts in IBS, identify risk genes and loci to be prioritized in independent follow-ups, and pinpoint ion channels as important players and potential therapeutic targets warranting further investigation.

The effects of vitamin B12 on the brain damages caused by methamphetamine in mice

Objective(s):

Methamphetamine (METH) is a powerful stimulant drug that directly affects the brain and induces neurological deficits. B₁₂ is a water-soluble vitamin (vit) that is reported to attenuate neuronal degeneration. The goal of the present study is to investigate the effect of vitamin B₁₂ on METH’s neurodegenerative changes.

Materials and Methods:

Two groups of 6 animals received METH (10 mg/kg, interaperitoneally (IP)) four times with a 2 hr interval. Thirty mins before METH administration, vit B12 (1 mg/kg) or normal saline were injected IP. Animals were sacrificed 3 days after the last administration. Caspase proteins levels were measured by Western blotting. Also, samples were examined by TUNEL assay to detect the presence of DNA fragmentation. Reduced glutathione (GSH) was also determined by the Ellman method.

Results:

The pathological findings showed that vit B₁₂ attenuates the gliosis induced by METH. Vit B₁₂ administration also significantly decreased the apoptotic index in the striatum and the cerebral cortex (P<0.001). It also reduced caspase markers compared to the control (P<0.01 and P<0.001, respectively). Interestingly, co-administration of METH and Vit B₁₂ elevates the levels of GSH in both regions of the brain and returned it to normal levels compared to the METH group.

Conclusion:

The current study suggests that parenteral vit B₁₂ at safe doses may be a promising treatment for METH-induced brain damage via inhibition of neuron apoptosis and increasing the reduced GSH level. Research focusing on the mechanisms involved in the protective responses of vit B₁₂ can be helpful in providing a novel therapeutic agent against METH-induced neurotoxicity.

TiO2-based Mitoxantrone Imprinted Poly (Methacrylic acid-co-polycaprolctone diacrylate) Nanoparticles as a Drug Delivery System

BACKGROUND

Light delivery in photodynamic therapy is a challenging issue in deep cancer treatment. To solve this problem, photosensitizers are conjugated to X-ray luminescent nanoparticles. When the complexes are stimulated by X-rays during radiotherapy, the nanoparticles generate light and activate the photosensitizers.

METHOD

Core-shell molecularly imprinted polymers (MIPs) were prepared against mitoxantrone (MX) in which TiO2 nanoparticles were applied as a core, diacrylated polycaprolctone as a biodegradable cross-linker and methacrylic acid (MAA) or 4-vinylpyridin (4-VP) as the functional monomer. TiO2 was selected as a scintillator, MX as a photosensitizer and MIP as a drug delivery system in order to evaluate the possibility of using photodynamic therapy (PDT) during radiotherapy in the next studies. Binding properties of polymers and drug release profile were studied and the optimized MIP was characterized by SEM, TEM, EDS, FT-IR and XRD. Also, cytotoxicity and free radical production were also studied in vitro.

RESULTS

Data indicated that MAA-based MIP had superior binding properties compared to its non-imprinted polymer (NIP) and higher imprinting factor value than MIP-4VP. Drug release experiments indicated higher MX released amount from MAA-based MIP than the other polymers. MAA-based MIP was selected as an optimized carrier for MX delivery system. According to the results, the size of MX-MIP@TiO2 was reported to be less than 75 nm. The free radical production and cytotoxicity of nanoparticles were also evaluated in vitro.

CONCLUSION

The results of the present work proposed the possibility of applying MIP layer as a drug delivery system around TiO2 nanoparticles.

Design, synthesis, and biological evaluation of 6-methoxy-2-arylquinolines as potential P-glycoprotein inhibitors

Objective(s):

In the present study, a new series of 6-methoxy-2-arylquinoline analogues was designed and synthesized as P-glycoprotein (P-gp) inhibitors using quinine and flavones as the lead compounds.

Materials and Methods:

The cytotoxic activity of the synthesized compounds was evaluated against two human cancer cell lines including EPG85-257RDB, multidrug-resistant gastric carcinoma cells (P-gp-positive gastric carcinoma cell line), and EPG85-257P, drug-sensitive gastric carcinoma cells. Compounds showing low to moderate toxicity in the MTT test were selected to investigate their P-gp inhibition activity. Moreover, trying to explain the results of biological experiments, docking studies of the selected compounds into the homology-modeled human P-gp, were carried out. The physicochemical and ADME properties of the compounds as drug candidate were also predicted.

Results:

Most of our compounds exhibited negligible or much lower cytotoxic effect in both cancer cells. Among the series, 5a and 5b, alcoholic quinoline derivatives were found to inhibit the efflux of rhodamine 123 at the concentration of 10 μM significantly.

Conclusion:

Among the tested quinolines, 5a and 5b showed the most potent P-gp inhibitory activity in the series and were 1.3-fold and 2.1-fold stronger than verapamil, respectively. SAR data revealed that hydroxyl methyl in position 4 of quinolines has a key role in P-gp efflux inhibition of our compounds. ADME studies suggested that all of the compounds included in this study may have a good human intestinal absorption.

3D-QSAR (CoMFA, CoMSIA) and Molecular Docking Studies on Histone Deacetylase 1 Selective Inhibitors

BACKGROUND

Histone deacetylases (HDACs) are attractive therapeutic targets for the treatment of cancer and other diseases. There are numerous published patent applications till 2017. It was claimed that novel HDACIs were optimized as potential drug candidates, designed for regional or systemic release, and created as significant inhibitors.

OBJECTIVE

In the present study, 3D-QSAR and molecular docking were used to provide a theoretical basis for finding highly potent anti-tumor drugs.

METHODS

QSAR was used to generate models and predict the HDAC1 inhibitory activity using the Sybyl program (x1.2 version). Biaryl benzamides (n=73) as selective HDAC1 inhibitors were selected as our data set, which was split randomly into training (n=63) and test sets (n=10). Docking was carried out using the MOE software. Partial least square was used as QSAR model-generation method. External validation and cross-validation (leave-one-out and leave-10-out) were used as validation methods.

RESULTS

Both CoMFA (q2, 0.663; rncv 2 , 0.909) and CoMSIA models (q2, 0.628; rncv 2 , 0.877) for training set yielded significant statistical results. The predictive ability of the derived models was examined by a test set of 10 compounds and external validation results displayed rpred 2 and rm 2 values of 0.767 and 0.664 for CoMFA and 0.722 and 0.750 for CoMSIA, respectively.

CONCLUSION

The obtained models showed a good predictive ability in both internal and external validation and could be used for designing new biaryl benzamides as potent HDAC1 inhibitors in cancer treatment. The amido and amine groups of benzamide part as scaffold and the bulk groups as a hydrophobic part were key factors to improve inhibitory activity of HDACIs.

The effects of crocin on the symptoms of depression in subjects with metabolic syndrome

BACKGROUND

Studies have suggested that metabolic syndrome (MetS) is associated with increased depressive symptoms, and reducing depression in subjects with MetS is important. Crocin, an active component of saffron, has useful properties for subjects with MetS, including antidepressant properties.

OBJECTIVES

The aim of the study was to assess the effect of a preparation of crocin on the symptoms of depression in subjects with MetS, and the relationship between changes in those symptoms and the serum pro-oxidant/anti-oxidant balance (PAB).

MATERIAL AND METHODS

This sub-study was carried out on 34 subjects with MetS from the authors' previous randomized double-blind controlled clinical trial (RCT), all of whom met the inclusion criteria for this study. The subjects were randomly assigned to treatment and placebo groups (n = 17 in each group) and received each 30 mg of crocin (2 tablets of 15 mg) or placebo for 8 weeks. Depressive symptoms were assessed using the Beck Depression Inventory (BDI). The BDI questionnaire was completed for each subject at the baseline and at the end of the 8th week of treatment. Blood samples were taken from the subjects before and after the intervention period. Statistical analyses were performed using the SPSS for Windows, v. 16 (SPSS Inc., Chicago, USA).

RESULTS

Out of the 34 participants enrolled, 33 completed the trial. The degree of depression decreased significantly in the crocin group (p = 0.005), but not in the placebo group (p > 0.05), and the difference between the 2 groups was statistically significant (p = 0.013). No significant relationship was observed between changes in depression symptoms and changes in the serum PAB (p > 0.05).

CONCLUSIONS

This study demonstrates that at a dose of 30 mg per day for 8 weeks, crocin reduced the symptoms of depression in subjects with MetS compared to the control group, and this effect was independent of its effect on the serum PAB.

Effect of crocin, a carotenoid from saffron, on plasma cholesteryl ester transfer protein and lipid profile in subjects with metabolic syndrome: A double blind randomized clinical trial

BACKGROUND

Metabolic syndrome is defined by insulin resistance and a clustering of other cardiovascular risk factors. Crocin is a carotenoid derived from the stigmas of the saffron flower and had previously been shown to affect lipid profile. However, the mechanism for this function is not well understood. The present trial aimed to investigate the possible effect of crocin on plasma levels of cholesteryl ester transfer protein and lipid profile in individuals with metabolic syndrome.

METHODS

This was a randomized, double-blind, placebo-controlled, clinical trial consisting of an 8-week treatment with crocin, or placebo tablets between April and June 2014, in the Nutrition Clinic of Ghaem Teaching Hospital, Mashhad, Iran. Participants were randomly assigned to take a 30 mg/day crocin (n = 22) in the intervention group or placebo (n = 22) in the control group. Anthropometric, hematological and biochemical parameters were measured and recorded during pre and post-treatment periods.

RESULTS

Whilst plasma cholesteryl ester transfer protein was increased in the group taking the crocin tablet by 27.81% during the trial period (P = 0.013), the difference between the crocin and placebo groups was not significant (P = 0.116). Moreover, the percent changes in cholesterol (P = 0.702), triglyceride (P = 0.080), low-density lipoprotein (LDL) (P = 0.986), high-density lipoprotein (HDL) (P = 0.687) and fasting blood glucose (P = 0.614) did not differ significantly between intervention and control groups.

CONCLUSION

Although crocin supplements increased the serum cholesteryl ester transfer protein in patients with metabolic syndrome, this change was not significant between treatment and placebo groups.

In vitro bactericidal activities of two novel dihydropyridine derivatives against Mycobacterium tuberculosis

INTRODUCTION

Introducing new and effective antitubercular agents is important in tuberculosis control programs. In this study, the in vitro antitubercular activity of two novel 1,4-dihydropyridine derivatives (F-27, Cl-33) were screened against a total of 113 different strains of Mycobacterium tuberculosis (77 susceptible and 36 resistant clinical isolates).

METHODOLOGY

The in vitro activities of these compounds were evaluated based on the modified broth macro-dilution assay.

RESULTS

Compound F-27 showed more than 90% growth inhibition at the range of 2 to 8 μg/mL (minimum inhibitory concentration [MIC]90: 4.13 ± 0.45 µg/mL; p  < 0.01), and complete growth inhibition was observed at the range of 8 to 32 μg/mL (minimum bactericidal concentration [MBC]: 11.2 ± 1.65 µg/mL; p < 0.01) against susceptible strains. However, 92% of the resistant strains showed some degree of susceptibility against this compound (MIC90 range: 16 to 64 µg/mL; mean: 40.4 ± 8 µg/mL; p < 0.01). It was found that although there is a linear relationship between the inhibitory activity of F-27 and isoniazid against resistant strains at low concentrations (r = 0.484, p < 0.001), there was no relationship between resistance to isoniazid and F-27 at higher concentrations (r = 0.019, p > 0.1). This may emphasize no cross-resistance between F-27 and isoniazid.

CONCLUSIONS

Considering the sufficient sample size of the study and based on the excellent antimycobacterial activity of F-27, it could be concluded that F-27 is a potent candidate as a lead compound, and may be considered for development of a new antitubercular agent.

In vitro evaluation of dihydropyridine-3-carbonitriles as potential cytotoxic agents through PIM-1 protein kinase inhibition

PIM-1 protein kinase inhibitor belongs to a novel class of serine/threonine kinases. As PIM-1 is overexpressed in cancer cells and possesses oncogenic functions, its inhibition provides a new option in cancer therapy. In this study, in vitro inhibitory effects of seven analogues of 1, 2-dihydropyridine-3-carbonitrile derivatives Ia-c, IIa-d on the activity of recombinant PIM-1 were evaluated using dimethylthiazol diphenyltetrazolium bromide (MTT) assay. The PIM-1 protein kinase inhibitory potencies and the cytotoxicity effects of tested compounds were respectively as follows: Ic > IIa > Ia > IIb > Ib > IId > IIc and IIb > IIa > Ia > IIc > Ic > Ib > IId, respectively. The compound Ic with methylthio imidazole substituent at C-3 position and benzodioxole substituent at C-6 position of 2-imino-1, 2-dihydropyridine-3- carbonitrile structure showed the strongest PIM-1 inhibitory effect (IC₅₀ = 111.01 nM), while the compound IIc with methythio imidazole substituent at C-3 position and benzodioxole substituent at C-6 position of 2-oxo-1, 2-dihydropyridine-3- carbonitrile structure exhibited the least inhibition activity (IC₅₀ = 433.71 nM). The docking results showed that all tested compounds localized appropriately in the middle of binding cavity after docking procedure, demonstrating suitable interactions between ligands and protein. This study demonstrated that the PIM-1 inhibitory potencies of newly synthesized compounds were in submicromolar concentrations (IC₅₀ < 150 nM) while they exhibited low cytotoxicity on HT-29 cell line (IC₅₀> 130 μM). Altogether, our data indicated that compounds Ic, IIa, Ia could be considered as new potent non-toxic PIM-1 inhibitors which could be used in combination with routine anti-proliferative drugs.