Synthesis of Silver Nanoparticles using Euphorbia wallichii Extract and Assessment of their Bio-functionalities

Silver nanoparticles synthesized by the bio-green method have been applied to various biomedical applications. These procedures are simple, eco-friendly and serve as an alternative to complex chemical methods for the preparation of nanomaterials.

In the present study, phytosynthesis of silver nanoparticles, to examine their antioxidant potential, toxic effects towards bacterial-, fungal-strains, brine shrimp nauplii and cancer cells was focused.

Methanolic extract of Euphorbia wallichii roots was used for the synthesis of silver nanoparticles. The synthesis was monitored and confirmed by UV-visible spectroscopy, Fourier Transform Infra-Red (FTIR) spectrometric analysis, Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray (EDX) and X-Ray Powder Diffraction (XRD).

The synthesized particles were average 63±8 nm in size. Involvement of phenolic (46.7±2.4 µg GAE/mg) and flavonoid (11.7±1.2 µg QE/mg) compounds as capping agents was also measured. Nanoparticles showed antioxidant properties in terms of free radical scavenging potential (59.63±1.0 %), reducing power (44.52±1.34 µg AAE/mg) and total antioxidant capacity (60.48±2.2 µg AAE/mg). The nanoparticles showed potent cytotoxic effects against brine shrimp nauplii (LD50 66.83 µg/ml), proliferation and cell death of HeLa cells as determined by MTT (LD50 0.3923 µg/ml) and TUNEL assays, respectively. Antimicrobial results revealed that silver nanoparticles were found to be more potent against pathogenic fungal (maximum active against A. fumigatus, MIC 15 µg/disc) and bacterial strains (maximum active against S. aureus, MIC 3.33 μg/disc) than the E. wallichii extract alone.

These results support the advantages of using an eco-friendly and cost-effective method for synthesis of nanoparticles with antioxidant, cytotoxic and antimicrobial potential.