Antimicrobial and Antioxidant Activities of Silver Nanoparticles Synthesized from Honeybee-Collected Pollen

Naturally collected pollen from plant flowers is known for its medicinal properties, including antibacterial, anti-inflammatory, and antioxidant. It is rich in bioactive compounds like polyphenols and flavonoids, making it a potent source for reducing and stabilizing silver nanoparticles (AgNPs). AgNPs possess distinct physicochemical properties that have attracted widespread interest due to their versatile applications. This study aimed to synthesize, characterize, and assess the antibacterial and antioxidant properties of Pol-AgNPs from pollen collected by honeybees. We successfully synthesized pollen extract as a natural reducing and stabilizing, alongside silver nitrate as a precursor. The UV–visible spectroscopy confirmed the formation of AgNPs by detecting distinct surface plasmon resonance (SPR) absorption peaks in the 400–450 nm range. Additional characterization techniques included Fourier-transform infrared spectroscopy (FT-IR) analysis to identify functional groups, X-ray diffraction (XRD) to reveal the face-centered cubic structure, and scanning electron microscopy (SEM) to verify the rod-shaped morphology. The disc diffusion method was employed to evaluate the antimicrobial activities of pollen extract collected from honeybees and pollen-derived silver nanoparticles (Pol-AgNPs). Notably, the Pol-AgNPs exhibited significant antimicrobial activity against gram-negative and gram-positive bacteria, with growth inhibition zones of 13.33 ± 1.15 mm against Pseudomonas aeruginosa (ATCC 27853) and 17.0 ± 0 mm against Enterococcus faecalis (ATCC 29212) at the concentration (100 μg/mL). Furthermore, the AgNPs demonstrated impressive antioxidant potential, scavenging DPPH (2,2-Diphenyl-1-picrylhydrazyl) radicals with an activity of 74.46 ± 0.22% at 400 μg/mL and half maximal inhibitory concentration (IC50) value of 48.58 ± 1.04 μg/mL. These findings underscore the effectiveness of honeybee-collected pollen-based AgNP synthesis and offer valuable insights into potential biomedical applications.