EVALUATION OF PHYTOCHEMICAL COMPONENTS, ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES OF SILVER NANOPARTICLES SYNTHESIZED USING Ricinus Communis LEAF EXTRACTS

Abstract

Silver nanoparticles are metal particles with nanoscale sized from 1-100 nm due to their small size they can be used in different fields like in medical application, environmental protection, in drug delivery, gene therapy, food processing etc. As necessary phytochemicals such as flavonoids, tannins and triterpenes were found to be present in R. communis leaf, its aqueous leaf extract was used in the present study to biosynthesize silver nanoparticles (NPs). A colour change from colourless to golden yellow then to brown color after 100 min incubation of “leaf extract plus AgNO3 reaction mixture” in the dark confirmed the formation of silver NPs. Absorption spectrum of silver NPs was studied between 400-700 nm and silver NPs were found to have absorption maximum at 440 nm. Binding of phenolic and flavonoids compounds with silver was confirmed by measuring their content in NPs. The antioxidant potential of synthesized silver NPs was evaluated by DPPH (2, 2-diphenyl-1-picrylhydrazyl) radical scavenging assay. Antioxidant assay showed that silver NPs had significantly high DPPH radical scavenging activity (60.54 %) than the aqueous leaf extract (44.49 %) of R. communis at P<0.05. The antibacterial activity of silver NPs against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria was evaluated by cup-plate agar diffusion method. R. communis leaf extract synthesized silver NPs showed good antibacterial activity against both gram-positive and gram-negative bacteria. The results suggest that R. communis leaf extract can be used effectively in the production of potential antioxidant and antimicrobial silver NPs, which have the potential to treat multidrug resistant microorganisms.