Alkanna tinctoria extract-mediated biomass synthesis of Ag-ZnO nanoparticles: characterization, antimicrobial and antibiofilm activities

Int Microbiol. 2025 Dec;28(8):3065-3078. doi: 10.1007/s10123-025-00743-7. Epub 2025 Nov 8.

Abstract

To combat the issue of pathogenic infections, the current work successfully synthesized a nanocomposite, which is based on the aqueous extract of Alkanna tinctoria (ATE) and silver-zinc oxide nanoparticles (ATE@Ag-ZnO NPs), using a green technique. Analytical methods were used to characterize the synthesized nanocomposite to verify its size, shape, distribution, surface charge, and crystallinity. The resulting nanocomposite created permanent colloidal nano-solutions, demonstrated excellent dispersion, and appeared at the nanoscale. The antimicrobial, antifungal, and antibiofilm characteristics of the ATE@Ag-ZnO nanocomposite were assessed. For every studied microbial strain, the ATE@Ag-ZnO nanocomposite's minimum inhibitory concentration (MIC) was determined. The encouraging findings showed that the MIC range of ATE@Ag-ZnO against all strains was 250-31.25 µg/mL. It demonstrated promise against S. epidermidis and A. calcoaceticus, with a MIC of 31.25 µg/mL. Furthermore, with inhibition zones of 22.0, 20.0, and 15.0 mm, respectively, the ATE@Ag-ZnO nanocomposite demonstrated antibacterial efficacy against gram-positive bacteria A. calcoaceticus, S. epidermidis, and C. tropicalis at 250 µg/mL. The highest percentage of inhibition (91.44%) was seen in S. aureus treated with 250 µg/mL ATE@Ag-ZnO nanocomposite, followed by A. calcoaceticus (68.83%) and C. albicans (64.81%). In conclusion, we successfully created the green synthesized ATE@Ag-ZnO nanocomposite, which demonstrated promising antibacterial, antifungal, and antibiofilm agents against some pathogenic microbes.

Keywords: Alkanna tinctoria; Antibiofilm activity; Antimicrobial potential; Membrane leakage assay; Nanoparticles.

MeSH terms

  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Anti-Infective Agents* / chemistry
  • Anti-Infective Agents* / pharmacology
  • Antifungal Agents / chemistry
  • Antifungal Agents / pharmacology
  • Bacteria / drug effects
  • Biofilms* / drug effects
  • Biomass
  • Bixaceae* / chemistry
  • Fungi / drug effects
  • Green Chemistry Technology
  • Metal Nanoparticles* / chemistry
  • Microbial Sensitivity Tests
  • Nanocomposites / chemistry
  • Plant Extracts* / chemistry
  • Plant Extracts* / pharmacology
  • Silver* / chemistry
  • Silver* / pharmacology
  • Zinc Oxide* / chemistry
  • Zinc Oxide* / pharmacology

Substances

  • Zinc Oxide
  • Plant Extracts
  • Silver
  • Anti-Bacterial Agents
  • Antifungal Agents
  • Anti-Infective Agents