Unlocking the Conformational Changes of P2Y₁₂: Exploring an Acridinone Compound’s Effect on Receptor Activity and Conformation

The P2Y12 receptor is an important member of the purinergic receptor family, known for its critical role in platelet activation and thrombosis. In our previously published study, the acridinone analogue NSC618159 was identified as a potent antagonist of P2Y12. In this work, we investigate the conformational changes in P2Y12 when bound to NSC618159 using molecular dynamics simulations on the receptor’s active and inactive forms (4PXZ and 4NTJ, respectively). It was observed that it took the systems about 7 ns and 12 ns to stabilise when NSC618159 was in complex with the active and inactive forms of P2Y12, respectively. Additionally, the binding pocket of the crystal structure 4PXZ expanded from 172.34 Å3 to an average of 661.55 Å3 when bound to NSC618159, with a maximum pocket volume of 820.49 Å3. This expansion was attributed to the pulled away transmembrane (TM) helices and the adoption of a more open conformation by extracellular loop 2 (EL2). In contrast, 4NTJ’s pocket volume was mostly consistent and had an average of 1203.82 Å3. Moreover, the RMSF profile of the NSC618159-4PXZ complex showed that residues of TM-I and TM-VII had similar fluctuations to the 4NTJ crystal structure, representing the inactive form of P2Y12. Finally, the energy components and binding affinities of NSC618159 towards the active and inactive forms of P2Y12 were predicted using the MM-PBSA approach. According to the results, the binding affinity of NSC618159 towards both active (4PXZ) and inactive (4NTJ) forms of P2Y12 was found to be almost identical, with values of −43.52 and −41.68 kcal/mol, respectively. In conclusion, our findings provide new insights into the conformational changes of P2Y12 upon binding to NSC618159 and may have implications for the development of new P2Y12 antagonists with enhanced potency and specificity

In Vivo Evaluation of Antirrhinum majus’ Wound-Healing Activity

Mediterranean-native perennial plant Antirrhinum majus was scrutinized in this study for its antioxidant activity and its total phenolic content in order to test for the plant’s wound-healing capability. The traditional uses of this plant to treat gum scurvy, various tumors, ulcers, and hemorrhoids were the main idea behind this study. Leaves and flowers of the A. majus were extracted by maceration. Pilot qualitative phytochemical tests were made to check the presence of various secondary metabolites. Quantitatively, the flowers’ macerate indicated superlative results regarding antioxidant activity and total phenolic content. However, the in vivo wound-healing capability study was made using 30 Wistar strain albino rats. This innovative part of the study revealed that the healing power of the flowers’ extract ointment (5% w/w) was superior compared to the leaves’ extract (5% w/w) and the positive-control ointments (MEBO) (1.5% w/w) (p ≤ 0.001). This activity was assessed by visual examination, wound-length measurement, and estimation of hydroxyproline content. Antirrhinum majus is a promising plant to be considered for wound healing. However, further testing (including histological examination and high-performance liquid chromatography (HPLC) analysis) is necessary to understand more about its mechanisms of action

Pharmacophore modeling and 3D-QSAR studies of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) inhibitors

1200-120615-Hydroxyprostaglandin dehydrogenase (15-PGDH) plays an important role in gastric ulcer healing, bone formation and dermal wound healing, encouraging several efforts to discover and optimize new inhibitors. We explored possible pharmacophoric space of 15-PGDH using four diverse sets of inhibitors. After that, GA and MLR methods have been employed to identify the optimal pharmacophore model(s) and physicochemical descriptors able to access Quantitative structure-activity relationship equation (r2=0.711, r2(adj)=0.6927, r2(LOO)= 0.6598). One pharmcophore model has emerged in the Quantitative structure-activity relationship equation and has been validated by ROC curve analysis and molecular docking

Heterocyclic Substitutions Greatly Improve Affinity and Stability of Folic Acid towards FRα. an In Silico Insight

Folate receptor alpha (FRα) is known as a biological marker for many cancers due to its overexpression in cancerous epithelial tissue. The folic acid (FA) binding affinity to the FRα active site provides a basis for designing more specific targets for FRα. Heterocyclic rings have been shown to interact with many receptors and are important to the metabolism and biological processes within the body. Nineteen FA analogs with substitution with various heterocyclic rings were designed to have higher affinity toward FRα. Molecular docking was used to study the binding affinity of designed analogs compared to FA, methotrexate (MTX), and pemetrexed (PTX). Out of 19 FA analogs, analogs with a tetrazole ring (FOL03) and benzothiophene ring (FOL08) showed the most negative binding energy and were able to interact with ASP81 and SER174 through hydrogen bonds and hydrophobic interactions with amino acids of the active site. Hence, 100 ns molecular dynamics (MD) simulations were carried out for FOL03, FOL08 compared to FA, MTX, and PTX. The root mean square deviation (RMSD) and root mean square fluctuation (RMSF) of FOL03 and FOL08 showed an apparent convergence similar to that of FA, and both of them entered the binding pocket (active site) from the pteridine part, while the glutamic part was stuck at the FRα pocket entrance during the MD simulations. Molecular mechanics Poisson-Boltzmann surface accessible (MM-PBSA) and H-bond analysis revealed that FOL03 and FOL08 created more negative free binding and electrostatic energy compared to FA and PTX, and both formed stronger H-bond interactions with ASP81 than FA with excellent H-bond profiles that led them to become bound tightly in the pocket. In addition, pocket volume calculations showed that the volumes of active site for FOL03 and FOL08 inside the FRα pocket were smaller than the FA–FRα system, indicating strong interactions between the protein active site residues with these new FA analogs compared to FA during the MD simulations

Pulmonary Delivery of Anticancer Drugs via Lipid-Based Nanocarriers for the Treatment of Lung Cancer: An Update

Lung cancer (LC) is the leading cause of cancer-related deaths, responsible for approximately 18.4% of all cancer mortalities in both sexes combined. The use of systemic therapeutics remains one of the primary treatments for LC. However, the therapeutic efficacy of these agents is limited due to their associated severe adverse effects, systemic toxicity and poor selectivity. In contrast, pulmonary delivery of anticancer drugs can provide many advantages over conventional routes. The inhalation route allows the direct delivery of chemotherapeutic agents to the target LC cells with high local concertation that may enhance the antitumor activity and lead to lower dosing and fewer systemic toxicities. Nevertheless, this route faces by many physiological barriers and technological challenges that may significantly affect the lung deposition, retention, and efficacy of anticancer drugs. The use of lipid-based nanocarriers could potentially overcome these problems owing to their unique characteristics, such as the ability to entrap drugs with various physicochemical properties, and their enhanced permeability and retention (EPR) effect for passive targeting. Besides, they can be functionalized with different targeting moieties for active targeting. This article highlights the physiological, physicochemical, and technological considerations for efficient inhalable anticancer delivery using lipid-based nanocarriers and their cutting-edge role in LC treatment