Evaluation of antioxidant, antimicrobial and antiproliferative activity of silver nanoparticles derived from Galphimia glauca leaf extract

Abstract

Objective: The bio-synthesis of silver nanoparticles (AgNPs) is regarded as environment friendly and cost effective method compared to physical and chemical synthesis methods. Silver (Ag) is an important noble metal due to its tremendous use in research and medical fields throughout the world. This research work was aimed at green synthesis and characterizations of AgNPs from G. glauca leaf extract and evaluation of their bioactive potential. Methods: In the current research work, synthesis of AgNPs from G. glauca aqueous leaf extracts was performed and was characterized by UV–Visible (UV–Vis.), Fourier transform infrared (FTIR), Atomic force microscopy (AFM), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), High-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Thermo gravimetric analysis (TGA) and Zeta potential exploration. Later, antioxidant, antimicrobial activity was examined against various pathogenic organisms and anticancer activities of AgNPs were carried out against SK-HEP1 cell line. Results: The first indication of synthesis of nanoparticles was the change in color from yellowish to brown. UV–Vis. band exhibited surface plasmon resonance (SPR) at 402 nm. FTIR analysis revealed the probable bio-molecules including alkanes, alkenes, aromatics, aromatic phosphates, imine or oxime, etc. subjected to reduction of silver ions to metallic silver. The AFM, SEM and TEM analysis reported the particles were spherical shaped, poly-dispersed, 17 to 40 nm in size. The zeta potential analysis expressed a peak at –32.0 ± 0.5 mV and suggested the particles with significant long term stability. The TGA analysis revealed the stability of AgNPs at high temperature (179 ℃). The antioxidant assay of AgNPs unveiled an effective dose dependent increase in scavenging activity. Antimicrobial activity showed efficient inhibitory activity against P. aeruginosa and C. glabrata. Lastly, the AgNPs revealed a strong anticancer activity against SK-HEP1 liver cancer cell line with an IC50 value of 19.12 μg/mL. Conclusions: Therefore, it could be concluded that a substantial in-vivo investigations are needed for antioxidant, antibacterial and anticancer activities, so that it will be useful in medical field in future.

Keywords

• Galphimia glauca
• Green synthesis
• Antioxidant
• Antimicrobial
• Anticancer
• SK-HEP1 cell line