Study of Antibacterial activity of Phyllanthus emblica and its role in Green Synthesis of Silver Nanoparticles

Objective: Phyllanthus emblica L. or amla is known for its therapeutic properties. The aim of the present study was to evaluate the antibacterial activity of aqueous Phyllanthus emblica fruit extract (APE) against eight pathogenic cultures and its application in green synthesis of silver nanoparticles. Methods: APE was screened for the presence of phytochemicals and its antibacterial activity was evaluated by agar well diffusion assay. The minimum inhibitory concentration (MIC) was quantified by broth macrodilution technique, and minimum bactericidal concentration (MBC) was determined. Further, APE was used in the biological synthesis of silver nanoparticles (AgNPs), which were characterized by an Ultraviolet–visible (UV-VIS) spectroscopy and Field emission gun-scanning electron microscopy (FEG-SEM) techniques. The antibacterial activity of the AgNPs was screened by agar well diffusion assay. Results: The zone of inhibition (ZOI) for APE was found to be in the range of 10.7–21.3 mm, for varying concentrations. The MIC values were in the range of 12.5% - 50% (v/v) and the MBC values indicated that a concentration of 50% (v/v) APE could kill 75% (6/8) test cultures. The presence of AgNPs was confirmed by UV-VIS spectroscopy and the surface-plasmon resonance peak was observed at 420 nm. The FEG-SEM analysis revealed that the most of AgNPs were spherical in shape and had 30-40 nm size range. All the test cultures were inhibited by the AgNPs and the average ZOI measured 19.25±2.7 mm. Conclusion: Phyllanthus emblica fruit extract might have therapeutic significance against pathogens and it can be used for green synthesis of silver nanoparticles. Keywords: Phyllanthus emblica, MIC, MBC, silver nanoparticles, UV-VIS, FEG-SEM