Anti-oxidant and Anti-microbial Activities of Silver Nanoparticles of Essential Oil Extracts from Leaves of Zanthoxylum ovalifolium

ABSTRACT

Aim: The present study was aimed to synthesis and characterization of silver nanoparticles (AgNPs) using Zanthoxylum ovalifolium leaf essential oil extracts and to screen the anti-oxidant and antimicrobial potential of the same. Place and Duration of Study The studies were carried out at Department of Botany, AVK College for Women, Hassan and Department of Biochemistry, Aurora’s Degree & PG College, Hyderabad from July 2017 to June 2018 Methodology: The essential oil from leaves of Zanthoxylum ovalifolium was obtained by hydrodistillation and analyzed by GC and GC-MS. Synthesis of silver nanoparticles of essential oil extract was carried out and characterized by using UV-VIS spectroscopy and transmission electron microscopy (TEM). The total phenolic and flavonoid contents were estimated in all the extracts. Furthermore, all the extracts were evaluated for anti-microbial activity against two gram-positive and two gram-negative bacteria and four pathogenic fungi using agar disc diffusion technique. Subsequently the minimum inhibitory concentration (MIC) was also determined. Results: The major compounds identified were Limonene, isofenchol, Geijerene, isothujanol, Borneol, dihydrocarveol, isobornyl acetate, pregeijerene, b-elemene, trans-caryophyllene and Germacrene D. The TEM analysis of nanoparticles synthesized showed a size of 8 to 14 nm with a lmax of 450nm. All the extracts were evaluated for in vitro anti-oxidant activity where the AgNP of essential oil extract showed maximum activity of 89.61% and 84.92% respectively for both DPPH free radical scavenging and Hydrogen peroxide free radical scavenging assays at a concentration of 100µg/ml. Among all the bacteria tested, B. subtilis was most susceptible at 100µg/ml with zone of inhibition of 22.5mm. While among all the fungi tested, A. niger inhibited more effectively by the AgNP of essential oil extract at 100µg/ml with a zone of inhibition of 16.2mm. Conclusion: The results obtained were remarkable suggesting that AgNP of essential oil extract possess excellent anti-oxidant and anti-microbial activity and can be an alternative bio-friendly source for various pharmaceutical industries.