Diflunisal Attenuates Virulence Factor Gene Regulation and Phenotypes in Staphylococcus aureus

Computational profiling and pharmacokinetic modelling of Febuxostat: Evaluating its potential as a therapeutic agent for diabetic wound healing

BACKGROUND

Diabetic wounds, a significant complication of Type 2 Diabetes Mellitus (T2DM), face delayed healing due to impaired inflammation, angiogenesis, and collagen synthesis. This study explores Febuxostat, a xanthine oxidase inhibitor for its therapeutic potential in wound healing. Combining computational approaches and in-vitro assays, the study evaluates its effects on key wound healing pathways, cell viability, migration.

METHODOLOGY

The potential of Febuxostat in diabetic wound healing was studied using in-silico tools for Molecular docking and ADMET profiling, alongside Molecular dynamics (MD) simulations. Toxicity was assessed with OSIRIS Explorer, and biological activity was predicted using the PASS tool. In-vitro MTT and scratch assays on L929 cells further validated cytotoxicity and wound healing efficacy.

RESULTS

Docking analysis revealed strong binding affinities to key wound healing targets, including VEGF (-9.11 kcal/mol) and NFKβ (-8.62 kcal/mol). Pharmacokinetic studies highlighted favorable skin permeability, supporting topical applications. Toxicity predictions indicated a safe profile. Molecular dynamics simulations demonstrated stable protein-ligand complexes, particularly with VEGF. Cytotoxicity studies on L929 cells revealed an IC50 of 6.08 μM and the scratch assay demonstrated significant wound healing activity, highlighting its effectiveness in promoting cell migration and closure.

CONCLUSION

Febuxostat shows remarkable potential in enhancing diabetic wound healing by promoting cell migration, targeting wound-healing proteins, as demonstrated through in-silico and in-vitro studies. This drug is poised to effectively treat diabetic wounds, accelerating healing and reducing complications. Rigorous pre-clinical and clinical evaluations are essential to validate its safety, efficacy, and therapeutic potential.

Exploring diflunisal as a synergistic agent against Staphylococcus aureus biofilm formation

Staphylococcus aureus is a bacterial pathogen of considerable significance in public health, capable of inducing a diverse range of infectious diseases. One of the most notorious mechanisms used by S. aureus to survive and colonize the site of infection is its ability to form biofilms. Diflunisal, a non-steroidal anti-inflammatory drug (NSAID), is a known inhibitor of the Agr system in S. aureus, which is key in regulating biofilm formation. This study evaluated the effect of broad-spectrum antibiotics in combination with diflunisal on S. aureus biofilm density. Eight antibiotics were tested independently at different concentrations and in combination with diflunisal to assess their effect on S. aureus biofilm formation. When using the antibiotics alone and with diflunisal, a significant control effect on biofilm formation was observed (p < 0.05), irrespective of diflunisal presence, but did not achieve a complete biofilm growth inhibition. Over time, diflunisal influenced biofilm formation; however, such an effect was correlated with antibiotic concentration and exposure time. With amikacin treatments, biofilm density increased with extended exposure time. In the case of imipenem, doripenem, levofloxacin, and ciprofloxacin, lower doses and absence of diflunisal showed higher control over biofilm growth with longer exposure. However, in all cases, diflunisal did not significantly affect the treatment effect on biofilm formation. In the absence of antibiotics, diflunisal significantly reduced biofilm formation by 53.12% (p < 0.05). This study suggests that diflunisal could be a potential treatment to control S. aureus biofilms, but it does not enhance biofilm inhibition when combined with antibiotics.

Diflunisal and Analogue Pharmacophores Mediating Suppression of Virulence Phenotypes in Staphylococcus aureus

Invasive methicillin-resistant Staphylococcus aureus (MRSA) infections are leading causes of morbidity and mortality that are complicated by increasing resistance to conventional antibiotics. Thus, minimizing virulence and enhancing antibiotic efficacy against MRSA is a public health imperative. We originally demonstrated that diflunisal (DIF; [2-hydroxy-5-(2,4-difluorophenyl) benzoic acid]) inhibits S. aureus virulence factor expression. To investigate pharmacophores that are active in this function, we evaluated a library of structural analogues for their efficacy to modulate virulence phenotypes in a panel of clinically relevant S. aureus isolates in vitro. Overall, the positions of the phenyl, hydroxyl, and carboxylic moieties and the presence or type of halogen (F vs. Cl) influenced the efficacy of compounds in suppressing hemolysis, proteolysis, and biofilm virulence phenotypes. Analogues lacking halogens inhibited proteolysis to an extent similar to DIF but were ineffective at reducing hemolysis or biofilm production. In contrast, most analogues lacking the hydroxyl or carboxylic acid groups did not suppress proteolysis but did mitigate hemolysis and biofilm production to an extent similar to DIF. Interestingly, chirality and the substitution of fluorine with chlorine resulted in a differential reduction in virulence phenotypes. Together, this pattern of data suggests virulence-suppressing pharmacophores of DIF and structural analogues integrate halogen, hydroxyl, and carboxylic acid moiety stereochemistry. The anti-virulence effects of DIF were achieved using concentrations that are safe in humans, do not impair platelet antimicrobial functions, do not affect S. aureus growth, and do not alter the efficacy of conventional antibiotics. These results offer proof of concept for using novel anti-virulence strategies as adjuvants to antibiotic therapy to address the challenge of MRSA infection.