Bio-fabricated silver nanoparticles from Ammannia nagpurensis leaf extracts: Antibacterial activity against antibiotic-resistant bacteria, therapeutic potential and in Silico docking analysis

The present study reports an eco-friendly method for synthesizing silver nanoparticles (AgNPs) using Ammannia nagpurensis leaf extract. The AgNPs were characterized by X-ray diffraction (XRD) showing face centered cubic crystalline structure with ~28.79 nm diameter. SEM analysis shows AgNPs were spherical in shape. The FT-IR (Fourier Transform infrared) spectrum showed the presence of different functional species (-CH, -O-H and -CO) in biological synthesis of AgNPs. The AgNPs were found to have uniform morphology and stability which was validated by scanning electron microscopy and zeta potential. The AgNPs demonstrated significant antioxidant activity (IC 50 = 57.21 µg/mL), anti-inflammatory effects (up to 91.2% inhibition, IC 50 = 132.36 µg/mL), and antidiabetic properties that were similar to those of acarbose (85.12% inhibition, IC 50 =71.97 µg/mL). The concentration dependent inhibition of bacterial growth was also found against test organisms where maximum efficacy was shown for K. pneumoniae (20 ± 0.5 mm), S. aureus (20 mm) and E. coli (19 ± 0.5 mm) at highest concentration. The outcomes highlighted the potential of AgNPs mediated by A. nagpurensis as sustainable nanomaterials for biomedical applications. Molecular docking studies revealed the antmicrobial efficacy by interacting with different virulent proteins of antimicrobial resistant K. pneumonia, S. aureus and E. coli.