Synthesis and evaluation of antibacterial and antioxidant effects of propolis nanoparticles and cinnamon nanostructures in preventive dentistry: Experimental and theoretical approaches.

Introduction: Natural products such as green propolis and cinnamon have been used traditionally in medicine due to their medicinal value. Recently, interest has grown in developing nanotechnology-based approaches to enhance the biological activity of these compounds.

Objective: This study evaluated the antioxidant and antibacterial properties of macro-sized and nanostructured forms of green propolis and cinnamon against Streptococcus mutans (S. mutans) and the 2,2-diphenyl-2-picrylhydrazyl (DPPH) assay.

Material and methods: The sonochemical method was used to synthesize green propolis nanoparticles (PNPs) and cinnamon nanoparticles (CNPs). Their size was confirmed by scanning electron microscopy (SEM) and dynamic light scattering measurements, while they were compared with propolis (P) and cinnamon (C). The antioxidant activity was measured using the DPPH assay, while the minimum inhibitory concentration (MIC) test determined the antibacterial activity against S. mutans. One-way analysis of variance (ANOVA) and Tukey's post hoc tests (α = 0.05) were conducted to analyze the data. Furthermore, docking calculations were carried out to examine the potential of incorporating any new supplements or therapies into your routine.

Results: The MIC were 5.46, 21.87, 21.87, and 175 g/L for PNPs, P, CNPs, and C groups, respectively. The PNPs exhibited the most significant antibacterial effect while C was weakest. About antioxidant activity, PNPs and P exhibited significant differences from other groups (P = 0.000 and 0.001, respectively), while CNPs and C showed no significant difference between each other (P = 0.07). The docking calculations revealed a strong interaction between both nanoparticles and S. mutans. The binding energy of dihydroflavonols on propolis nanoparticles was -6.83 kcal/mol, indicating a stable connection.