Biological Significance of Metallic Nanoparticles Synthesized via Plant Extracts

The rapidly evolving domain of metal nanoparticle (MNP) synthesis via plant-mediated green methodologies has garnered significant scientific interest due to their unique physicochemical properties and transformative potential in biotechnology and nanomedicine. Conventional synthesis methods, reliant on toxic reagents, high energy inputs, and posing environmental risks, have prompted a shift toward sustainable, plant-based approaches. These utilize plant extracts as eco-friendly reducing and capping agents, yielding biocompatible MNPs with controlled morphology, size, and enhanced stability. Such MNPs exhibit minimal toxicity, reduced environmental impact, and robust bioactivities, including antimicrobial, anticancer, antioxidant, and drug delivery capabilities, establishing them as pivotal in advanced therapeutic development. The cost-effectiveness, scalability, and integration of bioactive phytochemicals—such as polyphenols, flavonoids, and terpenoids—drive nanoparticle formation while imparting therapeutic benefits, notably through antioxidant mechanisms that mitigate oxidative stress by neutralizing free radicals. Over the past decade, leveraging medicinal plants has significantly advanced MNP functionality for biomedical applications. This chapter provides a comprehensive and systematic review of recent progress in plant-mediated MNP synthesis, focusing on the mechanistic contributions of phytochemicals to nanoparticle biogenesis and their resultant bioactivity. It critically evaluates commonly employed plant species, synthesis protocols, and underlying molecular mechanisms governing their efficacy. By integrating traditional botanical knowledge with cutting-edge nanotechnology, plant-derived MNPs offer a sustainable platform for developing safer, more effective biomedical solutions, addressing ecological concerns while enhancing therapeutic outcomes in pathogen resistance, cancer therapy, and targeted drug delivery. This chapter underscores the need for continued research to fully exploit these plant-based innovations for future nanomedicine advancements.