DefinePK

Abstract

Background: Green-synthesized nanoparticles offer eco-friendly and effective alternatives to conventional antimicrobial and antiparasitic therapies.
Objective: To evaluate the antimicrobial, antifungal, and antimalarial potential of Astragalus eremophilus-mediated silver nanoparticles.
Methodology: This experimental study was conducted at the Department of Biotechnology, Pakistan Institute of Medical Science (PIMS), Islamabad, from January to December 2023. Silver nanoparticles were synthesized using aqueous extract of A. eremophilus and characterized by UV–Vis spectrophotometry, FTIR, SEM, and DLS. Bioactivity assays included bacterial isolates (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa; n=115), fungal isolates (Candida albicans n=30, Aspergillus niger n=28), and Plasmodium falciparum cultures (n=20). Antimicrobial activity was tested by agar well diffusion, antifungal by poisoned food technique, and antimalarial by schizont maturation inhibition assay. Standard drugs (ampicillin, fluconazole, chloroquine) were used as controls. Data were analyzed using ANOVA with p<0.05 considered significant.
Results: Among bacterial isolates, inhibition was observed in S. aureus (76.21%), E. coli (72.39%), and P. aeruginosa (68.54%), all statistically significant (p<0.05). Fungal inhibition was 71.45% for C. albicans and 68.27% for A. niger, corresponding to relative inhibition of 86.75% and 86.27%, respectively. In P. falciparum cultures, inhibition increased dose-dependently from 52.34% at 25 µg/mL to 89.67% at 200 µg/mL, approaching chloroquine efficacy. Overall, the nanoparticles demonstrated consistent and broad-spectrum bioactivity across all tested pathogens.
Conclusion: Astragalus eremophilus-mediated silver nanoparticles exhibit significant broad-spectrum bioactivity, supporting their potential as sustainable therapeutic agents.