Synthesis of Silver Nanoparticles from Centella asiatica Leaves Extract and Their Antibacterial Activity Against Vibrio spp.

Abstract

The outbreak of Vibrio spp. bacteria that cause diseases in shrimp has continuously impacted the shrimp farming industry. Therefore, developing new strategies for pathogen control is crucial, especially the application of silver nanoparticles, which are well-known for their potent antimicrobial activity. In this study, silver nanoparticles were synthesized using a water extract of Centella asiatica leaves, which was mixed with 10 µM of AgNO₃ solution. The mixture was then incubated at room temperature, and changes were monitored using UV-Visible spectroscopy. The particle characteristics were analyzed using Transmission Electron Microscopy (TEM), and the antibacterial activity was evaluated using the Broth microdilution method to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the silver nanoparticles against four strains of Vibrio spp. The study found that the silver nanoparticle synthesis reaction began after the addition of the C. asiatica extract and reached its peak after 240 minutes of incubation. The synthesized silver nanoparticles were spherical in shape, with sizes ranging from 4 to 100 nanometers. The study on the effectiveness of the silver nanoparticles against four strains of Vibrio spp., including V. parahaemolyticus, V. vulnificus, V. mimicus, and V. fluvialis, using the Broth microdilution method. The silver nanoparticles were found to effectively inhibit the growth of bacterial pathogens. The MIC values were 15.63±0.00, 31.25±0.00, 15.63±0.00, and 15.63±0.00 ng/ml for V. parahaemolyticus, V. vulnificus, V. mimicus, and V. fluvialis, respectively. The MBC values, indicating bactericidal activity, were 31.25±0.00, 62.50±0.00, 31.25±0.00, and 15.63±0.00 ng/ml, respectively. These results demonstrate that the nanoparticles exhibited the highest bactericidal efficiency against V. fluvialis and the lowest against V. vulnificus. The findings from this study can be applied to the control and prevention of Vibrio spp. infections in shrimp, playing a key role in reducing antibiotic usage, promoting environmental sustainability, and enhancing the long-term sustainability of the shrimp farming industry.