The Effect of Nettle (Urtica dioica) Extract and Its Green-Synthesized Silver Nanoparticles on the Growth and Biofilm Formation of Streptococcus mutans
Archives of Advances in Biosciences,
Vol. 17 No. 1 (2026),
28 April 2026
,
Page 1-11
https://doi.org/10.22037/aab.v17i1.51429
Abstract
Background and Aim: The green biological synthesis of nanomaterials has attracted increasing attention due to its environmentally friendly nature and potential biomedical applications. This study aimed to comparatively evaluate the antibacterial and antibiofilm activities of aqueous Urtica dioica extract, its biosynthesized silver nanoparticles (AgNPs), and chlorhexidine against Streptococcus mutans PTCC 1683.
Methods: Silver nanoparticles were synthesized by adding aqueous U. dioica extract to a silver nitrate solution under controlled conditions. Key synthesis parameters, including extract volume, silver nitrate concentration, pH, and reaction time, were optimized to obtain stable nanoparticle formation. The resulting nanoparticles were characterized using UV–visible spectroscopy, FTIR, XRD, and SEM. Antimicrobial activity was assessed using agar well diffusion assay, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using standard broth dilution methods.
Results: Optimal synthesis conditions were achieved under neutral pH using 2 mL of plant extract and 4 mM silver nitrate. Characterization confirmed the formation of predominantly spherical nanoparticles with sizes in the range of 200–300 nm. In antibacterial assays, U. dioica aqueous extract showed the smallest inhibition zones, whereas AgNPs and chlorhexidine exhibited significantly stronger antibacterial activity. In biofilm assays, the aqueous extract demonstrated the lowest optical density (OD), indicating the strongest antibiofilm effect, while AgNPs and chlorhexidine showed comparable inhibitory effects on biofilm formation.
Conclusion: These findings suggest that Urtica dioica aqueous extract and its green-synthesized silver nanoparticles may serve as promising natural candidates for oral-care applications aimed at controlling S. mutans and dental caries. The results highlight their potential as alternative antimicrobial agents for biomedical and dental applications.
- Biofilm
- Green synthesis
- Silver nanoparticles
- Urtica dioica
- Streptococcus mutans
How to Cite
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