Biosynthesis of Silver Nanoparticles from Aqueous Extract of Salvia officinalis Aerial Parts and its Antibacterial Activities

Background and Objective: Medicinal plants used to combat diseases, they are of great importance for primary healthcare due to of their lesser costs, high safety margin and large biological activities. This study for Saliva officinalis L. aimed to synthesize silver nanoparticles from an aqueous extract of aerial parts as a reducing agent and evaluate its antibacterial potential. Materials and Methods: About 1 mL of 0.01 mM of silver nitrate was added to 5 mL of the prepared aqueous extract. The green synthesized silver nanoparticles were characterized by using UV-vis Spectroscopy and Fourier Transform Infrared Spectroscopy, antibacterial activity was evaluated by disk diffusion method against two Gram-negative (Klebsiella pneumonia and Pseudomonas aeruginosa) and one Gram-positive (Staphylococcus aureus) and was compared with the antibacterial activity of the aqueous extract. Results: Formation of silver nano particles by reduction of silver ions into silver element was indicated by the change of colour of the reaction mixture from pale yellow to dark brown colour. The UV-vis Spectroscopy absorption peak is obtained in the visible range at 410 nm confirmed the formation of silver nanoparticles. Fourier Transform Infrared Spectroscopy confirmed the presence of ingredients in Salvia extract which are responsible for the capping and reduction of the silver. The disk diffusion method results showed potent antibacterial activity against the three bacteria species, showing higher antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa and medium activity against Klebsiella pneumonia. Conclusion: Aqueous silver nanoparticle extracts are found to be more effective against all bacteria studied than the normal aqueous extract so it can improve the activity of the plant extract and it can be further investigated for biomedical applications.