Mechanism of Antiradical Activity of Coumarin-Trihydroxybenzohydrazide Derivatives: A Comprehensive Kinetic DFT Study

As part of this study, the mechanisms of the antioxidant activity of previously synthesized coumarin-trihydrobenzohydrazine derivatives were investigated: (E)-2,4-dioxo-3-(1-(2-(2″,3″,4″-trihydroxybenzoyl)hydrazineyl)ethylidene)chroman-7-yl acetate (1) and (E)-2,4-dioxo-3-(1-(2-(3″,4″,5″-trihydroxybenzoyl)hydrazineyl)ethylidene)chroman-7-yl acetate (2). The capacity of the compounds to neutralize HO• was assessed by EPR spectroscopy. The standard mechanisms of antioxidant action, Hydrogen Atom Transfer (HAT), Sequential Proton Loss followed by Electron Transfer (SPLET), Single-Electron Transfer followed by Proton Transfer (SET-PT), and Radical Adduct/Coupling Formation (RAF/RCF) were examined using the QM-ORSA methodology. It was estimated that the newly synthesized compounds, under physiological conditions, exhibited antiradical activity via SPLET and RCF mechanisms. Based on the estimated overall rate constants (koverall), it can be concluded that 2 exhibited a greater antiradical capacity. The obtained values indicated a good correlation with the EPR spectroscopy results. Both compounds exhibit approximately 1.5 times more activity in comparison to the precursor compound used in the synthesis (gallic acid).

An Effective, Green Synthesis Procedure for Obtaining Coumarin-Hydroxybenzohydrazide Derivatives and Assessment of Their Antioxidant Activity and Redox Status

In this study, green synthesis of two derivatives of coumarin-hydroxybenzohydrazide, (E)-2,4-dioxo-3-(1-(2-(2,3,4-trihydroxybenzoyl)hydrazyl)ethylidene)-chroman-7-yl acetate (C-HB1), and (E)-2,4-dioxo-3-(1-(2-(3,4,5-trihydroxybenzoyl)hydrazyl)ethylidene)chroman-7-yl acetate (C-HB2) is reported. Using vinegar and ethanol as a catalyst and solvent, the reactions were carried out between 3-acetyl-4-hydroxy-coumarin acetate and corresponding trihydroxybenzoyl hydrazide. The antioxidant potential of these compounds was investigated using the DPPH and ABTS assays, as well as the FRAP test. The obtained results reveal that even at very low concentrations, these compounds show excellent radical scavenging potential. The IC50 values for C-HB1 and C-HB2 in relation to the DPPH radical are 6.4 and 2.5 μM, respectively, while they are 4.5 and 2.0 μM in relation to the ABTS radical. These compounds have antioxidant activity that is comparable to well-known antioxidants such as gallic acid, NDGA, and trolox. These results are in good correlation with theoretical parameters describing these reactions. Moreover, it was found that inhibition of DPPH● follows HAT, while inactivation of ABTS+● follows SET-PT and HAT mechanisms. Additionally, coumarin-hydroxybenzohydrazide derivatives induced moderate cytotoxic activity and show significant potential to modulate redox status in HCT-116 colorectal cancer cells. The cytotoxicity was achieved via their prooxidative activity and ability to induce oxidative stress in cancer cells by increasing O2˙- concentrations, indicated by increased MDA and GSH levels. Thus, ROS manipulation can be a potential target for cancer therapies by coumarins, as cancer cells possess an altered redox balance in comparison to normal cells. According to the ADMET analysis, the compounds investigated show good pharmacokinetic and toxicological profiles similar to vitamin C and gallic acid, which makes them good candidates for application in various fields of industry and medicine.

Five-year disease-free survival in FIGO IA stage endometrial cancer patients: Tertiary institution experience in a developing country

Purpose

Endometrial cancer is characterized as histopathological, molecular, genetic, biological, and very diverse group of malignancies. Due to the need to precisely define the indications for adjuvant treatment in recent years, there has been a division made according to risk groups based on prognostic factors, which identify patients at risk for disease relapse, who may benefit from adjuvant therapy. The aim of this research was to examine the clinical and morphological factors that influence disease-free survival (DFS) and overall survival (OS) in patients with FIGO IA stage endometrial cancer.

Material and methods

A retrospective clinical study was conducted, primarily based on the identification of factors that influence five-year DFS and OS. The study integrated data of FIGO IA stage endometrial cancer patients, who presented to gynecological oncology board for the first time after operative treatment, from January 1, 2016 to January 1, 2022. Adjuvant radiotherapy was applied to patients with an initially higher risk of disease progression. Length of survival was analyzed using Kaplan-Meier method, while log-rank test was used to assess differences between groups.

Results

The results show that 5-year OS for 93 patients was 89.2% and DFS was 88.2%. Application of adjuvant brachytherapy, number of deliveries, MRI staging, type of institution where the surgery was performed influenced DFS. Pathohistological characteristics of tumor indicated a statistically significant impact on DFS.

Conclusions

Application of adjuvant brachytherapy in high-intermediate and high-risk patients contributes to DFS increase. Moreover, the existence of a pre-operative MRI assessment of the stage of disease as well as the type of healthcare provided by an institution where the surgery was performed, significantly affect DFS.

Investigational new drugs for the treatment of Dravet syndrome: an update

INTRODUCTION

While there are already approved anticonvulsants for treatment of children with Dravet syndrome, disease modifying therapy is at its beginning.

AREAS COVERED

This narrative review is updating the latest information about efficacy and safety of both anticonvulsant and disease modifying investigational drugs for Dravet syndrome. Relevant publications were searched for in MEDLINE, GOOGLE SCHOLAR, SCINDEKS, and CLINICALTRIALS.GOV databases, from the dates of their foundation till January 2023.

EXPERT OPINION

The main advancements were made in the treatment of Dravet syndrome with confirmed haploinsufficiency of SCN1A gene. The application of antisense oligonucleotides has so far proven to be the most successful within disease-modifying therapy, but it also requires further refinement of the methodology of application and delivery to target cells, as well as additional testing of the effectiveness of antisense oligonucleotides outside of TANGO technology. Also, the full potential of gene therapy has yet to be explored, given that high capacity adenoviral vectors that can incorporate the SCN1A gene have recently been prepared.

Degradation Mechanisms of 4,7-Dihydroxycoumarin Derivatives in Advanced Oxidation Processes: Experimental and Kinetic DFT Study

Coumarins represent a broad class of compounds with pronounced pharmacological properties and therapeutic potential. The pursuit of the commercialization of these compounds requires the establishment of controlled and highly efficient degradation processes, such as advanced oxidation processes (AOPs). Application of this methodology necessitates a comprehensive understanding of the degradation mechanisms of these compounds. For this reason, possible reaction routes between HO^• and recently synthesized aminophenol 4,7-dihydroxycoumarin derivatives, as model systems, were examined using electron paramagnetic resonance (EPR) spectroscopy and a quantum mechanical approach (a QM-ORSA methodology) based on density functional theory (DFT). The EPR results indicated that all compounds had significantly reduced amounts of HO^• radicals present in the reaction system under physiological conditions. The kinetic DFT study showed that all investigated compounds reacted with HO^• via HAT/PCET and SPLET mechanisms. The estimated overall rate constants (k_overall) correlated with the EPR results satisfactorily. Unlike HO^• radicals, the newly formed radicals did not show (or showed negligible) activity towards biomolecule models representing biological targets. Inactivation of the formed radical species through the synergistic action of O₂/NO_x or the subsequent reaction with HO^• was thermodynamically favored. The ecotoxicity assessment of the starting compounds and oxidation products, formed in multistage reactions with O₂/NO_x and HO^•, indicated that the formed products showed lower acute and chronic toxicity effects on aquatic organisms than the starting compounds, which is a prerequisite for the application of AOPs procedures in the degradation of compounds.

In silico study of inhibitory capacity of sacubitril/valsartan toward neprilysin and angiotensin receptor

Heart failure (HF) is a life-threatening condition that occurs when the heart cannot pump enough blood and oxygen to meet the body's needs. It affects mostly the elderly, commonly from the male population, especially those with obesity, diabetes, or some other chronic condition. It can be treated with different medications, and promising results were shown by a relatively new medicament called Entresto. Results obtained from molecular docking and molecular dynamics simulations to examine the inhibitory capacity of Entresto are presented in this study. Parameters obtained by the molecular docking simulations show that both parts of Entresto (sacubitril (SAC) and valsartan (VAL)) interact with targeted proteins, and inhibit their physiological function. Simulations of molecular dynamics revealed some interesting inhibitory patterns. SAC was discovered to produce structural alterations in neprilysin by binding to it, reducing neprilysin's physiological activity. In addition to blocking the active site, SAC binding causes the enzyme's structure to become less compact over time, causing changes in its biochemical characteristics and preventing the enzyme from performing its biological function. Similar to SAC, VAL also causes deviations in the structure of angiotensin receptors. The angiotensin receptor GPCR (G-protein-coupled receptors) is immersed in the lipid bilayer, and changes in the tertiary structure are only visible through RMSD and RMSF, not by examining R g. In this regard, MD simulations validated the results of molecular docking simulations, demonstrating that both SAC and VAL had inhibitory potential towards the neprilysin and angiotensin receptors, respectively.

Analysis of Treatment-Related Factors Affecting Mortality in Patients with Severe Necrotizing Acute Pancreatitis

The aim of the paper was to determine the factors related to the initial therapy that may contribute to death from severe necrotizing acute pancreatitis and to analyze their clinical importance as well as possible additive effects.

A retrospective case-control study included all adult patients treated for severe necrotizing acute pancreatitis in the Clinical Center of Kragujevac, Serbia, during the five-year period (2006-2010.). The cases (n = 41) were patients who died, while the controls (n = 69) were participants who survived. In order to estimate the relationship between potential risk factors and observed outcome, crude and adjusted odds ratios (OR) with 95 % confidence intervals (CI) were calculated in logistic regression models.

Significant association with observed outcome was shown for the use of gelatin and/or hydroxyethyl starch (adjusted OR 12.555; 95 % CI 1.150-137.005), use of albumin (adjusted OR 27.973; 95 % CI 1.741-449.373), use of octreotide (adjusted OR 16.069; 95 % CI 1.072-240.821) and avoiding of enteral feeding (adjusted OR 3.933; 95 % CI 1.118-13.829), while the use of nonsteroidal anti-inflammatory drugs had protective role (adjusted OR 0.057; 95 % CI 0.004-0.805).

The risk of death in patients with predicted severe necrotizing acute pancreatitis could be reduced with avoidance of treatment with colloid solutions, albumin and octreotide, as well as with an early introduction of oral/enteral nutrition and use of nonsteroidal anti-inflammatory drugs.