Green synthesis of calcium hydroxide-coated silver nanoparticles using Andrographis paniculata and Ocimum sanctum Linn. leaf extracts: An antimicrobial and cytotoxic activity

CONTEXT: Silver is known for its antibacterial properties since ages. As nanoparticles have smaller size and greater surface area, silver has been utilized in the form of nanoparticles to enhance its antibacterial properties. Calcium hydroxide is a well-known intracanal medicament and serves as a gold standard for root canal disinfection. Using herbal extracts as reducing agents for nanoparticle synthesis appears to be an ecofriendly approach. AIM: The aim of this study was to synthesize calcium hydroxide-based silver nanoparticles using herbs as reducing agents and to test the cytotoxic levels and antimicrobial activity against oral microbes. MATERIALS AND METHODS: The calcium hydroxide-based silver nanoparticles were synthesized using the leaves of Andrographis paniculata and Ocimum sanctum Linn. Various properties of the synthesized nanoparticles were also characterized by ultraviolet (UV) spectrophotometer analysis, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) analysis. The cytotoxic effects of these nanoparticles were analyzed using brine shrimp and MTT assay. Antimicrobial activity was assessed by measuring the zone of inhibition. The statistical analysis was done using parametric independent t-test. P value was set at < 0.05. RESULTS: The calcium hydroxide-based silver nanoparticles were successfully synthesized and were confirmed by UV spectrophotometer analysis, TEM, X-ray diffraction (XRD), and FTIR analysis and showed a minimal cytotoxic effect. They also showed a good antimicrobial activity and a remarkable antifungal activity. CONCLUSIONS: The green synthesis of CaOHAgNPs yielded an effective nanoparticle preparation that could be used against common oral pathogens as a potential therapeutic agent in the form of root canal irrigant or intracanal medicament in the field of dentistry.