Discovery of dual-target natural antimalarial agents against DHODH and PMT of Plasmodium falciparum: pharmacophore modelling, molecular docking, quantum mechanics, and molecular dynamics simulations

Malaria is a lethal disease that claims thousands of lives worldwide annually. The objective of this study was to identify new natural compounds that can target two P. falciparum enzymes; P. falciparum Dihydroorotate dehydrogenase (PfDHODH) and P. falciparum phosphoethanolamine methyltransferase (PfPMT). To accomplish this, e-pharmacophore modelling and molecular docking were employed against PfDHODH. Following this, 1201 natural compounds with docking scores of ≤ -7 kcal/mol were docked into the active site of the second enzyme PMT. The top nine compounds were subjected to further investigation using MM-GBSA free binding energy calculations and ADME analysis. The results revealed favourable free binding energy values better than the references, as well as acceptable pharmacokinetic properties. Compounds ZINC000013377887, ZINC000015113777, and ZINC000085595753 were scrutinized to assess their interaction stability with the PfDHODH enzyme, and chemical stability reactivity using molecular dynamics (MD) simulation and density functional theory (DFT) calculations. These findings indicate that the three natural compounds are potential candidates for dual PfDHODH and PfPMT inhibitors for malaria treatment.

Unlocking the potential of approved drugs for the allosteric inhibition of tropomyosin-receptor kinase A using molecular docking and molecular dynamics studies

Tropomyosin-receptor kinase A (TrkA) is the primary isoform among the tropomyosin-receptor kinases that have been associated with human cancer development, contributing to approximately 7.4% of all cancer cases. TrkA represents an attractive target for cancer treatment; however, currently available TrkA inhibitors face limitations in terms of resistance development and potential toxicity. Hence, the objective of this study was to identify new allosteric-approved inhibitors of TrkA that can overcome these challenges and be employed in cancer therapy. To achieve this goal, a screening of 9,923 drugs from the ChEMBL database was conducted to assess their repurposing potential using molecular docking. The top 49 drug candidates, exhibiting the highest docking scores (-11.569 to -7.962 kcal/mol), underwent MM-GBSA calculations to evaluate their binding energies. Delanzomib and tibalosin, the top two drugs with docking scores of -10.643 and -10.184 kcal/mol, respectively, along with MM-GBSA dG bind values of -67.96 and -50.54 kcal/mol, were subjected to 200 ns molecular dynamic simulations, confirming their stable interactions with TrkA. Based on these findings, we recommend further experimental evaluation of delanzomib and tibalosin to determine their potential as allosteric inhibitors of TrkA. These drugs have the potential to provide more effective and less toxic therapeutic alternatives. The approach employed in this study, which involves repurposing drugs through molecular docking and molecular dynamics, serves as a valuable tool for identifying novel drug candidates with distinct therapeutic uses. This methodology can contribute to reducing the attrition rate and expediting the process of drug discovery.

Design of Novel Letrozole Analogues Targeting Aromatase for Breast Cancer: Molecular Docking, Molecular Dynamics, and Theoretical Studies on Gold Nanoparticles

The use of aromatase inhibitors is an established therapy for estrogen-dependent breast cancer in postmenopausal women. However, the only commercially available aromatase inhibitor, letrozole, is not highly selective; in addition to aromatase, it has an affinity for binding to desmolase, an enzyme involved in steroidogenesis, which explains the main side effects. Therefore, we designed new compounds based on the structure of letrozole. More than five thousand compounds were constructed based on the letrozole structure. Then, these compounds were screened for their binding ability toward the target protein, aromatase. Quantum docking, Glide docking, and ADME studies showed 14 new molecules with docking scores of ≤-7 kcal/mol, compared to the docking score of -4.109 kcal/mol of the reference, letrozole. Moreover, molecular dynamics (MD) and post-MD MM-GBSA calculations were calculated for the top three compounds, and the results supported in their interaction's stability. Finally, the density-functional theory (DFT) study applied to the top compound to study the interaction with gold nanoparticles revealed the most stable position for the interaction with the gold nanoparticles. The results of this study confirmed that these newly designed compounds could be useful starting points for lead optimization. Further in vitro and in vivo studies are recommended for these compounds to verify these promising results experimentally.

Identification of Novel Natural Dual HDAC and Hsp90 Inhibitors for Metastatic TNBC Using e-Pharmacophore Modeling, Molecular Docking, and Molecular Dynamics Studies

Breast cancer (BC) is one of the main types of cancer that endangers women's lives. The characteristics of triple-negative breast cancer (TNBC) include a high rate of recurrence and the capacity for metastasis; therefore, new therapies are urgently needed to combat TNBC. Dual targeting HDAC6 and Hsp90 has shown good synergistic effects in treating metastatic TNBC. The goal of this study was to find potential HDAC6 and Hsp90 dual inhibitors. Therefore, several in silico approaches have been used. An e-pharmacophore model generation based on the HDAC6-ligand complex and subsequently a pharmacophore-based virtual screening on 270,450 natural compounds from the ZINC were performed, which resulted in 12,663 compounds that corresponded to the obtained pharmacophoric hypothesis. These compounds were docked into HDAC6 and Hsp90. This resulted in the identification of three compounds with good docking scores and favorable free binding energy against the two targets. The top three compounds, namely ZINC000096116556, ZINC000020761262, and ZINC000217668954, were further subjected to ADME prediction and molecular dynamic simulations, which showed promising results in terms of pharmacokinetic properties and stability. As a result, these three compounds can be considered potential HDAC6 and Hsp90 dual inhibitors and are recommended for experimental evaluation.

Infant feeding practice and gastrointestinal tolerance: a real-world, multi-country, cross-sectional observational study

BACKGROUND

Signs of feeding intolerance, such as gastrointestinal (GI) symptoms, are frequently observed in otherwise healthy formula-fed infants in the first months of life. The primary objective of this observational study was to examine GI tolerance in formula-fed infants (FFI) vs. breastfed infants (BFI) in a real-world setting with a secondary objective being the comparison of infants fed formula with pre- and/or probiotics (FFI_PP) and those fed formula without any pre- and/or probiotics (FFI_noPP) as well as BFI.

METHODS

A six-country, cross-sectional study in full-term exclusively/predominantly FFI (n = 2036) and BFI (n = 760) aged 6-16 weeks was conducted using the validated Infant Gastrointestinal Symptom Questionnaire (IGSQ) and a Feeding Practice and Gut Comfort Questionnaire.

RESULTS

The IGSQ composite score in FFI was non-inferior compared to BFI (mean difference [95%CI]: 0.17 [-0.34, 0.67]; non-inferiority p-value < 0.0001) and scores for BFI and FFI were below the threshold of 23, indicating no GI discomfort. Adjusted mean IGSQ scores ± SE were similar in FFI_PP (22.1 ± 0.2) and BFI (22.3 ± 0.3) while FFI_noPP (23.4 ± 0.3) was significantly higher and above 23 indicating some GI discomfort (mean differences [95%CI] FFI_noPP minus FFI_PP and FFI_noPP minus BFI were 1.28 [0.57, 1.98] and 1.09 [0.38, 1.80], respectively; both p < 0.01). Hard stools and difficulty in passing stool were more common in FFI compared to BFI (p < 0.01) but were less common in FFI_PP compared to FFI_noPP (p < 0.01). FFI_PP showed significantly less crying than FFI_noPP and was similar to BFI. Significantly fewer physician-confirmed colic episodes (Rome IV criteria) were reported in FFI_PP compared with FFI_noPP or BFI.

CONCLUSIONS

In this real-world observational study, FFI had non-inferior overall GI tolerance compared to BFI. Within FFI, infants receiving formulas with pre- and/or probiotics had a better GI tolerance, improved stooling and less infantile colic compared to those receiving formula without any pre- and/or probiotics and were more similar to BFI.

TRIAL REGISTRATION

NCT03703583, 12/10/2018 ( https://clinicaltrials.gov/ct2/show/NCT03703583 ).

Changes in aortic valve hemodynamics and ventricular functional measurements in patients undergoing transcatheter and surgical aortic valve replacement: a head-to-head comparison

Introduction

Both surgical and transcatheter aortic valve replacement are effective interventions for treatment of patients with severe aortic stenosis. Data from landmark randomized trials have shown comparable improvement in aortic valve hemodynamics and left ventricular remodeling. Whether similar patterns will be observed in real-world practice has not been completely investigated.

Purpose

To compare the impact of transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) on short- and intermediate-term changes in aortic valve hemodynamics and left ventricular reverse-remodeling.

Methods

A total of 213 patients with severe AS were referred for TAVR (n=137) or SAVR (n=76) at a single center (August/ 2015-Feb/ 2021). Patient demographics and echocardiographic parameters of aortic valve stenosis severity were collected retrospectively. Changes over-time in aortic valve area, mean gradient, dimensionless index, left ventricular ejection fraction (EF), and ventricular septal thickness were examined using linear mixed models.

Results

Patients undergoing TAVR were older with higher STS risk scores and a greater burden of comorbidities (Table). Over a median follow-up of 13 months (IQR 4–31), both groups experienced a significant reduction in aortic valve mean gradient (25.7 mmHg with TAVR and 18.8 mmHg with SAVR), with no significant between-group difference (P=0.15). Aortic valve dimensionless index significantly increased in TAVR and SAVR groups (0.23 and 0.13, respectively) and was more pronounced in the TAVR group (P=0.01). Similarly, aortic valve area increased significantly in both groups (0.66 cm2 and 0.42 cm2, respectively) without a significant across-group difference (P=0.07). On the other hand, left ventricular ejection fraction did not change significantly over time (−0.61 and 1.15 EF points, respectively) with no significant between-group difference at 12 months (P=0.06). Ventricular septal thickness was significantly reduced in both groups, with no significant between group difference (P=0.4; Figure).

Conclusion

In this real-world experience, both TAVR and SAVR were associated with significant improvement in aortic valve hemodynamic parameters and modest reverse left ventricular remodeling. Furthermore, these changes were comparable with both modalities, adding to available evidence from randomized clinical trials on beneficial effects of both TAVR and SAVR.

Funding Acknowledgement

Type of funding sources: None. Table 1Figure 1

Seroprevalence and risk factors for hepatitis B and C virus infection in Damietta Governorate, Egypt

Hepatitis B and C virus (HBV and HCV) infections remain major public health problems in Egypt and data are needed on risk factors for infection. This study determined the prevalence of anti-HCV and HBV surface antigen seropositivity in Damietta Governorate, Egypt, and evaluated potential risk factors for infection and the impact of HBV vaccination on seroprevalence. A household, cross-sectional study was conducted of 2977 individuals. About 20% were vaccinated against HBV. Only 1.1% were infected with HBV and 9.3% with HCV; both infections coexisted in 12 people (0.4%) (all unvaccinated). The main risk factors for both HCV and HBV were exposure to dental procedures, surgery, stitches, schistosomiasis treatment and contact with infected person. HBV and HCV prevalences in Damietta were lower than the national rate, likely due to the routine compulsory HBV vaccination in those aged < 19 years. There is a need to educate the general population about HBV and HCV transmission routes and avoidance of risky behaviours.

Neovascularization of the amniotic membrane as a biological immune barrier

The clinical application of islet transplantation is limited due to the limited source and the morbidity of systemic immunosuppression to prevent rejection. The two problems can be solved by using encapsulated islets. We have used amniotic membranes as biocompatible natural immune barriers. The objective of this study was to assess the revascularization of the membrane, which is necessary to ensure islet viability when the membrane is used for islet encapsulation. The amniotic membranes, obtained from full-term pregnant female dogs, were molded to form macrocapsules, which were implanted in the peritoneal cavity. The capsules were removed after 3, 10, 15, and 30 days and examined histopathologically using hematoxylin and eosin and by immunohistochemistry for neovascularization using factor VIII to detect angiogenesis. Upon histopathological examination, all specimens showed localized, moderate inflammation and congested blood vessels with no thrombosis or rejection. There was a mild degree of fibroblast proliferation starting from day 10 to day 30. Immunohistochemical staining revealed that the number of blood vessels was 7, 11, 13, 10 per high-power microscopic field on days 3, 10, 15, and 30, respectively. We concluded from this study that implanted amniotic sac capsules were vascularized within the omental tissue from day 10 on with significant blood vessel formation starting on day 3 by immunohistochemical study.

Three-dimensional mapping of temporo-limbic regions and the lateral ventricles in schizophrenia: gender effects

BACKGROUND

Local alterations in morphological parameters are poorly characterized in several brain regions widely implicated in schizophrenia neuropathology.

METHODS

Surface-based anatomical modeling was applied to magnetic resonance data to obtain three-dimensional (3D) average anatomical maps and measures of location, shape, asymmetry, and volume for the lateral ventricles, hippocampus, amygdala, and superior temporal gyrus in schizophrenic (n = 25; 15 male) and normal subjects (n = 28; 15 male) matched for demographic variables. For all regions, intra-group variability was visualized and group differences assessed statistically to discriminate local alterations in anatomy across sex and diagnosis.

RESULTS

Posterior hippocampal volumes, lengths, and widths were reduced in patients. The right amygdala showed volume increases in schizophrenia patients versus controls. Ventricular enlargements, pronounced in the left hemisphere, occurred in the superior and lateral dimensions in patients, and these effects interacted with gender. Superior horn anterior extremes, inferior horn volumes, and hippocampal asymmetries exhibited gender effects. Significant group differences were absent in superior temporal gyrus parameters. Finally, regional variability profiles differed across groups.

CONCLUSIONS

Clear morphometric differences of the lateral ventricles, hippocampus, and amygdala indicate regional displacements and shape distortions in several functional systems in schizophrenia. Alterations in these structures as mapped in 3D may provide the foundation for establishing brain abnormalities not previously defined at such a local level.

Encapsulation of orange oil in a spray dried double emulsion

Encapsulation is an important technique being used to protect sensitive food materials like flavours from deterioration. The capsule wall isolates them from the atmospheric oxygen, moisture, temperature and light. Encapsulation also masks some objectionable flavours, e.g. fish oil and some bitter antibiotics. In this study orange oil was encapsulated in the inner compartment of a double emulsion belonging to the type O1-W-O2 where O1 is orange oil, W is water and O2 is vegetable oil. In order to make orange oil double emulsion suitable for use in dry mixes, it was secondarily coated with wall materials of lactose and caseinate using spray drying technique. Entrapment of orange oil in such structure is also expected to slow down the release of volatiles and guarantee more protection for orange oil against atmospheric conditions. This method may have a potential application in different types of food or pharmaceutical products where maximum protection for flavours or slow release are required. This study includes detailed preparation of the spray dried double emulsion, evaluation of the encapsulation efficiency using light and scanning electron microscope and calculation of the yield percent of the encapsulated oil. In a separate paper we will examine the efficiency of spray dried double emulsion to control the release of orange oil by GC.