Abstract
The process of producing the metallic nanoparticles (MNPs) in a sustainable and environment- friendly process is very desirable due to environmental hazards posed by climatic changes. Biomedical one of the fields classified under nanoscience, nanoparticles have a potential synthetic application, which makes it a vast area of research. These particles can be prepared using chemical, physical, and biological methods. One of the methods of synthesis of nanoparticles is by the use of plant extracts, known as green synthesis. Because of its low cost and nontoxicity, it has gained attention in recent times. This review was conducted to find the possible outcomes and uses of metallic nanoparticles synthesized using different parts like gum, root, stem, leaf, fruits, etc. of Azadirachta indica (AI). AI, a popular medicinal plant commonly known as neem, has been studied for the green synthesis of NPs by using the capping and reducing agents secreted by the plant. Various phytochemicals identified in neem are capable of metal ion reduction. Green synthesis of NPs from neem is an eco-friendly and low-cost method. These NPs are reported to exhibit good antimicrobial activity. The review covers the preparation, characterization, and mechanism associated with the antibacterial, anticancer, and neurological diseases of the MNPs. Furthermore, the limitations associated with the existing NPs and the prospects of these NPs are also examined.