Abstract

Green chemistry has emerged as a sustainable and environmentally benign approach to nanoparticle synthesis, replacing toxic chemical reducing agents with plant-derived phytochemicals. In the context of Ayurveda, medicinal plants—long valued for their therapeutic potential—offer a rich source of bioactive molecules capable of acting as reducing, capping, and stabilizing agents for metal and metal-oxide nanoparticles. This review critically examines the chemistry of plant-mediated synthesis of therapeutic nanoparticles, focusing on reaction mechanisms, structure–property relationships, and biomedical relevance. Polyphenols, flavonoids, terpenoids, alkaloids, and reducing sugars from Ayurvedic plants such as Azadirachta indica, Tinospora cordifolia, Withania somnifera, Phyllanthus emblica, and Ocimum sanctum play dual roles in nanoparticle formation and surface functionalization, leading to controlled size, morphology, and stability. Green-synthesized silver, gold, zinc oxide, copper oxide, and iron oxide nanoparticles exhibit enhanced antimicrobial, anticancer, antioxidant, and wound-healing properties due to their biofunctionalized surfaces. However, challenges remain in reproducibility, scale-up, toxicity assessment, and standardization of plant extracts. This paper integrates the latest fifteen years of research (2010–2025) to present a coherent chemical framework for plant-based nanoparticle synthesis and its translational potential in nanomedicine.