Abstract

ACTIVITY OF SILVER NANOPARTICLES SYNTHESIZED USING AQUEOUS LEAF EXTRACT OF SONCHUS ASPER AGAINST POTENTIAL HUMAN PATHOGENIC BACTERIA

Abha Verma*, Arvind Arya and Prakash Joshi

ABSTRACT

Silver nanoparticles exhibit magnificent applications as antimicrobial agent. The present study deals with firstly the preparation of aqueous leaf extract of a weed namely Sonchus asper using three different methods including decoction, cold percolation and soxhlet procedure. The efficiency of the extraction process was determined in terms of extractive yield. Among the three procedures used, the soxhlet process was found to give maximum yield. The phytochemical analysis of the extract (SSAaq) revealed the presence of Reducing sugar, Protein, Phenol, Alkaloid, Steroid, Saponin, Tannins and was therefore used for the reduction of silver nitrate leading to the production of silver nanoparticles. The bio-reduction was monitored by UV-Vis spectrophotometer and further characterized by X-Ray diffraction analysis and Fourier transforms infra red spectroscopy. The aqueous extract and silver nanoparticles were then tested for their potential as antimicrobials against potential human pathogenic bacteria by agar well diffusion method. Among the Gram positive bacteria the silver nanoparticles were found to have maximum activity against Staphylococcus aureus followed by Streptococcus sp. whereas among the Gram negative cultures activity was found to be maximum for Escherichia coli and almost similar for Proteus vulgaris, Klebsiella pneumonia, Salmonella sp. The study clearly shows that the silver nanoparticles, synthesized using aqueous leaf extract of Sonchus asper, exhibit good and potent antimicrobial activity against potential human pathogenic bacteria.

Keywords: Sonchus asper, aqueous leaf extract, silver nanoparticles, agar well diffusion method.