Plant mediated synthesis of silver nanoparticles and their biological applications

Abstract

The green synthesis of nanoparticles using plants and their extracts is considered as a representative approach in material synthesis for environmental benignity. Numerous metal nanoparticles with potential bioactivities have been prepared based on plant extracts. In this paper, we report an eco-friendly technique for the preparation of silver nanoparticles using plant extract of Justicia diffusa Willd. and the evaluation of their antioxidant, antidiabetic, and cytotoxicity activities. UV-visible spectroscopy, transmission electron microscopy, scanning electron microscopy and atomic force microscopy analysis were used to characterize the morphology and size of silver nanoparticles. The stability of silver nanoparticles toward acidity, alkalinity, salinity and temperature showed that they remained stable at room temperature for more than two months. UV-vis spectrum of the aqueous medium containing silver nanoparticles showed an absorption peak at around 420 nm. The scanning electron microscopy analysis of the silver nanoparticles showed that they have a uniform spherical shape with an average size in the range of 40-78 nm. This was confirmed by transmission electron microscopy analysis which showed an average size of about 50 nm. Thus green system showed better capping and stabilizing agent for the fine particles. Further 1-diphenyl-2picrylhydrazl radical in Justicia diffusa mediated silver nanoparticles showed a maximum activity of 67% at concentration of 200 μg/mL. Hydrogen peroxide scavenging assay in Justicia diffusa mediated silver nanoparticles showed a maximum activity of 89% at concentration of 200 μg/mL. Reducing power of Justicia diffusa silver nanoparticles exhibited a higher activity of 246 μg/mL at concentration of 200 μg/mL. These NPs showed the cytotoxic effects against brine shrimp (Artemia salina) Nauplii with a value of 35% and LD value of 271 μg/mL. The AgNPs synthesized using Justicia diffusa Willd. extract also show remarkable antidiabetic activities.

Green Synthesis and Characterization of Iron Nanoparticles Synthesized from Aqueous Leaf Extract of Vitex leucoxylon and Its Biomedical Applications

“…Using a phosphate buffer and hydrogen-peroxide-free blank solution, we assessed the solution’s absorbance at 230 nm after 10 min. Phosphate buffer was used to create the control instead of the sample or standard [ 33 ]. Each sample was tested three times.…”

Fabrication and characterization of Hypecoum pendulum‐assisted novel bio‐inspired silver nanoparticles and their antioxidant, anti‐diabetic, and anti‐Alzheimer properties

“…Nanotechnology is the greatest and chief interdisciplinary branch of science that refers to the preparation of nanoscale matter and its unusual optoelectronic and physicalchemical properties. [28] The biogenic synthesis of NPs using plant materials has perceived notable importance because it is an efficient, safe, rapid, nonpathogenic, and economically cheap approach. [61,62] Moreover, the phytochemicals present in the plant extract act as stabilizers and reducers for silver ions and, therefore, speed up the rate of reaction.…”

“…In many in vitro and in vivo studies, plant‐mediated silver nanoparticles have been recommended as inhibitors of alpha‐amylase. [ 28–30 ]…”

“…In many in vitro and in vivo studies, plant-mediated silver nanoparticles have been recommended as inhibitors of alpha-amylase. [28][29][30] The most prevalent neurodegenerative disorder, that is, Alzheimer's disease (AD), causes irreversible damage to nerve cells as a result of the development of tangles and plaques. [31,32] Though, various features such as getting old, genetic history, head trauma, protein deposit, oxidative stress, low level of neurotransmitter acetylthiocholine (AcSCh), and cholinergic deficit have been reported as causes of AD.…”