Repurposing Amphotericin B: anti-microbial, molecular docking and molecular dynamics simulation studies suggest inhibition potential of Amphotericin B against MRSA

Amphotericin B (AMPH) is an anti-fungal drug and this study, for the first time as best of our knowledge, reports the repurposing of the Amphotericin B. The drug was found to show significant antibacterial potential revealed by antimicrobial screening, molecular docking, and mode of action analysis targeting Penicillin Binding Protein 2a (PBP 2a protein) which is target of β-lactam drugs and is involved in cell wall synthesis. Mode of action analysis showed the drug to have hydrophobic and hydrophilic interactions with both C-terminal, trans-peptidase and non-penicillin binding domain of the protein. Additionally, to evaluate the impact of ligand binding on the protein's conformational dynamics, molecular dynamics (MD) simulations were used. Comparative Dynamical flexibility (RMSF) and Dynamics Cross Correlation (DCCM) followed by MD simulations revealed the complex formation significantly effecting structural dynamics of the enzyme significantly in the non-penicillin binding domain (327-668) and slightly in trans peptidase domain. Radius of gyration assessment further showed ligand binding also decreasing over all compactness of protein. Secondary structure analysis indicated the complex formation changing the conformational integrity in non-penicillin binding domain. Hydrogen bond analysis and MMPBSA, free energy of calculations followed by MD simulations, also complemented the antimicrobial and molecular docking revelations suggesting Amphotericin B to have substantial antibacterial potential.

Cohort event monitoring of patients treated for uncomplicated malaria with artemisinin-based combination therapies in selected hospitals and community pharmacies in Nigeria

AIMS AND OBJECTIVES

The study was designed with the broad objective of determining the safety profile of artemisinin-based combination therapies amongst Nigerian population.

PATIENTS AND METHODS

This was a cohort event monitoring (CEM) programme involving monitoring adverse events (AEs) in malaria patients treated with either artemether-lumefantrine (AL) or artesunate-amodiaquine (AA) in healthcare facilities in Nigeria. The study involved continuous enrolment of patients with malaria and treated with either AL or AA at the various sites until a total cohort of 600 patients were enrolled at each site. Patients were monitored from the onset of therapy, and on days 3 and 7 from the first day of treatment to identify AEs that may occur.

RESULTS

A total of 6102 AEs were recorded in 10,259 patients monitored during the programme. Of 4896 patients who received AA, 4233 (86.5%) patients reported at least one AE while 1869 (34.8%) AEs out of 5363 patients who received AL were reported (P = 0.010). The predominant incidence of each specific AE reported in each group among the patients who received AA and AL includes body weakness 30.8%/7.5%, dizziness 10.3%/3.9%, restlessness 5.02/1.12%, vomiting 3.5/1.03% and drowsiness 3.1/1.5% for AA and AL, respectively. There were more AEs among patients with co-morbid conditions and patients in the younger age groups (9-<15 years), P = 0.000.

CONCLUSIONS

Various types of AEs were seen and documented during the CEM programme. The findings suggested that the AA/AL monitored during this programme was generally safe and remarkably well tolerated among the Nigerian populations.