Synthesis of ZnO nanoparticles using insulin-rich leaf extract: Anti-diabetic, antibiofilm and anti-oxidant properties

J Photochem Photobiol B. 2019 Aug:197:111541. doi: 10.1016/j.jphotobiol.2019.111541. Epub 2019 Jun 25.


Here, we report the novel fabrication of ZnO nanoparticles using the Costus igneus leaf extract. Gas chromatography-mass spectrometry (GC-MS) and proton nuclear magnetic resonance (1H NMR) spectroscopy to determine the bioactive components present in the plant extract. The synthesis of Ci-ZnO NPs (C. igneus- coated zinc oxide nanoparticles) was accomplished using a cost-effective and simple technique. Ci-ZnO NPs were specified using UV-visible spectroscopy, FTIR, XRD, and TEM. Ci-ZnO NPs was authenticated by UV-Vis and exhibited a peak at 365 nm. The XRD spectra proved the crystalline character of the Ci-ZnO NPs synthesized as hexagonal wurtzite. The FTIR spectrum illustrated the presence of possible functional groups present in Ci-ZnO NPs. The TEM micrograph showed evidence of the presence of a hexagonal organization with a size of 26.55 nm typical of Ci-ZnO NPs. The α-amylase and α-glucosidase inhibition assays demonstrated antidiabetic activity of Ci-ZnO NPs (74 % and 82 %, respectively), and the DPPH [2,2-diphenyl-1-picrylhydrazyl hydrate] assay demonstrated the antioxidant activity of the nanoparticles (75%) at a concentration of 100 μg/ml. The Ci-ZnO NPs exhibited promising antibacterial and biofilm inhibition activity against the pathogenic bacteria Streptococcus mutans, Lysinibacillus fusiformis, Proteus vulgaris, and Vibrio parahaemolyticus. Additionally, the Ci-ZnO NPs showed biocompatibility with mammalian RBCs with minimum hemolytic activity (0.633 % ± 0.005 %) at a concentration of 200 μg/ml.

Keywords: Biological properties; Biosynthesis; Costus igneus; TEM; XRD; ZnO nanoparticles.

MeSH terms

  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Antioxidants / chemistry*
  • Biocompatible Materials / chemistry
  • Biocompatible Materials / pharmacology
  • Biofilms / drug effects*
  • Costus / chemistry
  • Costus / metabolism
  • Erythrocytes / cytology
  • Erythrocytes / drug effects
  • Erythrocytes / metabolism
  • Gas Chromatography-Mass Spectrometry
  • Gram-Negative Bacteria / drug effects
  • Gram-Negative Bacteria / physiology
  • Gram-Positive Bacteria / drug effects
  • Gram-Positive Bacteria / physiology
  • Green Chemistry Technology
  • Hemolysis / drug effects
  • Humans
  • Insulin / chemistry
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / toxicity
  • Microbial Sensitivity Tests
  • Particle Size
  • Plant Extracts / chemistry*
  • Plant Extracts / metabolism
  • Plant Leaves / chemistry
  • Plant Leaves / metabolism
  • Zinc Oxide / chemistry*
  • alpha-Amylases / antagonists & inhibitors
  • alpha-Amylases / metabolism


  • Anti-Bacterial Agents
  • Antioxidants
  • Biocompatible Materials
  • Insulin
  • Plant Extracts
  • alpha-Amylases
  • Zinc Oxide