Selenium nanoparticle synthesis from endangered medicinal herb (Enicostema axillare).

Green synthesis of selenium nanoparticles (SeNPs) was achieved by a simple biological procedure using the reducing power of E. axillare leaf extract. This method is capable of producing SeNPs in a size range of around 56.23-98.18 nm, under ambient lab condition. The synthesized nanoparticles were characterized by UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Energy-dispersive X-Ray (EDX). To check the potential hazards of nanotoxicity median lethal concentration (LC50) and Na + /K + -ATPase activity was assessed on zebra fish which showed the LC50 of 258.72 ppm for 96 h and Na + /K + -ATPase seems to significantly decrease with increase in SeNPs concentration. Antibactericidal activity explored the use of SeNPs against wide range of pathogens. Cytotoxicity of SeNPs was assayed against human lung cancer cells (A549) confirmed that SeNPs are able to inhibit the cell growth by dose-dependent manner. In conclusion, green synthesized selenium nanoparticles are less toxic and harmless. This is the first report on green synthesized selenium nanoparticles using E. axillare possessing anti-bacterial and anti-cancer activity.