Synthesis and characterization ofAzadirachta indicaconstructed silver nanoparticles and their immunomodulatory activity in fish

Abstract

Green synthesis of nanoparticles by using different biological agents has emerged as an alternative to overcome the toxic effect of chemically synthesized nanoparticles. Among various biological agents, plants are mostly preferred. This study describes an eco‐friendly and green synthesis of silver nanoparticles (G‐AgNPs) using Azadirachta indica (neem) as a reducing agent. UV–Vis spectral analysis proved the wavelength of sample to be 420 nm, approaching the surface resonance peak specific for G‐AgNPs. Dynamic light scattering (DLS) analysis showed the mean diameter of particles as 35.4 nm with zeta potential +34.6 mV. TEM results revealed the compact and spherical shape of the particles. Fourier transform infrared spectroscopies (FT‐IR) demonstrate the presence of possible functional groups involved in synthesis of the silver nanoparticles. The functional activity of immunological parameters, such as nitroblue tetrazolium assay, myeloperoxidase activity, phagocytic activity, anti‐protease and lysozyme activity, increased significantly (P < 0.05) in fish treated with G‐AgNPs. Relative percentage survival (74%) and enhanced disease resistance were observed in G‐AgNP‐treated Cirrhinus mrigala fingerlings challenged with Aeromonas hydrophila. In summary, present results demonstrate biosynthesized silver nanoparticles have immunomodulatory and antibacterial activity.

Biosynthesis, characterization and anti-dengue vector activity of silver nanoparticles prepared from Azadirachta indica and Citrullus colocynthis

“…The peaks of 1616 cm −1 might indicate presence of C=C bonds or aromatic rings attributed to carbonyl stretch in proteins [ 40 ]. The absorption bands appearing at 1244, 1161, 1097 and 1027 cm −1 can be assigned to the C–H alkene (aliphatic amines, C–H wag, C–N stretching in amide functional group) and C–O vibrations of ether linkages [ 14 , 39 , 41 ]. Thus, FTIR analysis of A.indica -mediated AgNPs confirmed the presence of different phytochemical components such as flavonoids, polyphenols and terpenoids of A. indica extract which potentially played a vital role in the reduction of Ag+ ions to Ag 0 atoms.…”

“…Thus, FTIR analysis of A.indica-mediated AgNPs confirmed the presence of different phytochemical components such as flavonoids, polyphenols and terpenoids of A. indica extract which potentially played a vital role in the reduction of Ag+ ions to Ag 0 atoms. Especially the proteins (due to the carbonyl and NH 2 of amino acid) present in A. indica leaves extract served as reducing and encapsulating agent because carbonyl group can reside on the metallic silver due to strong affinity for metals and thus developing a capping layer on surfaces of AgNPs [20,36,39,41]. For the AgNPs prepared by C. colocynthis, FTIR spectrum exhibited peaks at 3255, 2920, 2361, 2341, 1634, 1582, 1404, 1339, 1240, 1141, 1095, 1007 and 953 cm −1 as shown in figure 8b.…”

Green synthesis of gold nanoparticles using Turnera diffusa Willd enhanced antimicrobial properties and immune response in Longfin yellowtail leukocytes

“…It is important to note that ROS production and oxidative stress induction have been described as a consequence of nanoparticle toxicity, which altered cellular proteins and caused cell death (Wang et al, 2014). Interestingly, in vivo immunomodulatory activity of green synthesis of silver nanoparticles using Neem Azadirachta indica have been observed in Cirrhinus mrigala —an important freshwater fish—where respiratory burst activity by NBT, phagocytosis and myeloperoxidase activities increased (Rather et al, 2016). Several antimicrobial immune mechanisms have been described in normal polymorphonuclear leukocytes and phagocytes.…”

Potential medicinal plants for improve the immune system from Borneo Island and the prospect to be developed as nanomedicine

“…It might be due the G-AgNP has activated an alternative pathway that only can be done by nanoscale particles that increase the immunomodulation activity. Nevertheless, the mechanism of immunomodulatory effects of G-AgNPs needs to be investigated further [43].…”