Potent Inhibition of Bacterial DNA Gyrase by Digallic Acid and Other Gallate Derivatives

In silico study to identify novel NEK7 inhibitors from natural sources by a combination strategy

Cancer poses a significant global health challenge and significantly contributes to mortality. NEK7, related to the NIMA protein kinase family, plays a crucial role in spindle assembly and cell division. The dysregulation of NEK7 is closely linked to the onset and progression of various cancers, especially colon and breast cancer, making it a promising target for cancer therapy. Nevertheless, the shortage of high-quality NEK7 inhibitors highlights the need for new therapeutic strategies. In this study, we utilized a multidisciplinary approach, including virtual screening, molecular docking, pharmacokinetics, molecular dynamics simulations (MDs), and MM/PBSA calculations, to evaluate natural compounds as NEK7 inhibitors comprehensively. Through various docking strategies, we identified three natural compounds: (-)-balanol, digallic acid, and scutellarin. Molecular docking revealed significant interactions at residues such as GLU112 and ALA114, with docking scores of -15.054, -13.059, and -11.547 kcal/mol, respectively, highlighting their potential as NEK7 inhibitors. MDs confirmed the stability of these compounds at the NEK7-binding site. Hydrogen bond analysis during simulations revealed consistent interactions, supporting their strong binding capacity. MM/PBSA analysis identified other crucial amino acids contributing to binding affinity, including ILE20, VAL28, ILE75, LEU93, ALA94, LYS143, PHE148, LEU160, and THR161, crucial for stabilizing the complex. This research demonstrated that these compounds exceeded dabrafenib in binding energy, according to MM/PBSA calculations, underscoring their effectiveness as NEK7 inhibitors. ADME/T predictions showed lower oral toxicity for these compounds, suggesting their potential for further development. This study highlights the promise of these natural compounds as bases for creating more potent derivatives with significant biological activities, paving the way for future experimental validation.

Discovery of digallic acid as XOD/URAT1 dual target inhibitor for the treatment of hyperuricemia

The development of XOD/URAT1 dual target inhibitors has emerged as a promising therapeutic strategy for the management of hyperuricemia. Here, through virtual screening, we have identified digallic acid as a novel dual target inhibitor of XOD/URAT1 and subsequently evaluated its pharmacological properties, pharmacokinetics, and toxicities. Digallic acid inhibited URAT1 with an IC50 of 5.34 ± 0.65 μM, which is less potent than benzbromarone (2.01 ± 0.36 μM) but more potent than lesinurad (10.36 ± 1.23 μM). Docking and mutation analysis indicated that residues S35, F241 and R477 of URAT1 confer a high affinity for digallic acid. Digallic acid inhibited XOD with an IC50 of 1.04 ± 0.23 μM. Its metabolic product, gallic acid, inhibited XOD with an IC50 of 0.91 ± 0.14 μM. Enzyme kinetic studies indicated that both digallic acid and gallic acid act as mixed-type XOD inhibitors. It shares the same binding mode as digallic acid, and residues E802, R880, F914, T1010, N768 and F1009 contribute to their high affinity. The anion group (carboxyl) of digallic acid contribute significantly to its inhibition activity on both XOD and URAT1 as indicated by docking analysis. Remarkably, at a dosage of 10 mg/kg in vivo, digallic acid exhibited a stronger urate-lowering and uricosuric effect compared to the positive drug benzbromarone and lesinurad. Pharmacokinetic study indicated that digallic acid can be hydrolyzed into gallic acid in vivo and has a t1/2 of 0.77 ± 0.10 h. Further toxicity evaluation indicated that digallic acid exhibited no obvious renal toxicity, as reflected by CCK-8, biochemical analysis (CR and BUN) and HE examination. The findings of our study can provide valuable insights for the development of XOD/URAT1 dual target inhibitors, and digallic acid deserves further investigation as a potential anti-hyperuricemic drug.

Antimicrobial Potential of Polyphenols: An Update on Alternative for Combating Antimicrobial Resistance

The last decade has encountered an increasing demand for plant-based natural antibiotics. This demand has led to more research-based investigations for natural sources of antimicrobial agents and published reports demonstrating that plant extracts are widely applied in modern medicine, reporting potential activity that may be due to polyphenol compounds. Interestingly, the effects of polyphenols on the sensitivity of bacteria to antibiotics have not been well-studied. Hence, the current review encompasses the prospective application of plant-based phenolic extracts from plants of Indian origin. The emergence of resistance to antimicrobial agents has increased the inefficacy of many antimicrobial drugs. Several strategies have been developed in recent times to overcome this issue. A combination of antimicrobial agents is employed for the failing antibiotics, which restores the desirable effect but may have toxicity-related issues. Phytochemicals such as some polyphenols have demonstrated their potent activity as antimicrobial agents of natural origin to work against resistance issues. These agents alone or in combination with certain antibiotics have been shown to enhance the antimicrobial activity against a spectrum of microbes. However, the information regarding the mechanisms and structure-activity relationships remains elusive. The present review also focuses on the possible mechanisms of natural compounds based on their structure- activity relationships for incorporating polyphenolic compounds in the drug-development processes. Besides this work, polyphenols could reduce drug dosage and may diminish the unhidden or hidden side effects of antibiotics. Pre-clinical findings have provided strong evidence that polyphenolic compounds, individually and in combination with already approved antibiotics, work well against the development of resistance. However, more studies must focus on in vivo results, and clinical research needs to specify the importance of polyphenol-based antibacterials in clinical trials.