Recent developments in green synthesis of nanoparticles using Murraya koenigii for multifunctional applications

The eco-friendly synthesis of metal nanoparticles (NPs) has gained immense attention due to its sustainable, cost-effective, and non-toxic nature. Among various biological methods, plant-mediated synthesis is considered the most efficient, with Murraya koenigii (curry leaf) emerging as a potent bio-reductant and stabilizing agent. This review highlights the phytochemical-rich M. koenigii leaf extract, which contains alkaloids, flavonoids, terpenoids, phenolics, and carbazole alkaloids that actively participate in the bioreduction of metal ions into stable nanoparticles. The synthesis process is discussed with emphasis on the role of phytoconstituents, extraction procedures, and green reaction mechanisms. Characterization techniques such as UV–Vis, XRD, FTIR, SEM, TEM, TGA, and zeta potential analysis validate the morphology, crystallinity, elemental composition, and surface properties of the biosynthesized nanoparticles. The synthesized NPs exhibit promising multifunctional properties, particularly in biomedical and environmental domains. Antimicrobial studies demonstrate effective inhibition of both Gram-positive and Gram-negative bacteria, while anticancer evaluations show apoptosis induction in cancer cells through ROS generation and mitochondrial disruption. Additionally, antioxidant activity highlights the potential for oxidative stress modulation. In environmental remediation, these NPs act as efficient catalysts in the degradation of toxic dyes from wastewater, offering a green solution to pollution control. This comprehensive review not only summarizes the mechanistic insights, synthesis protocols, and applications of M. koenigii-mediated metal nanoparticles but also underscores their significance in advancing green nanotechnology. The findings establish M. koenigii as a valuable resource for sustainable nanoparticle synthesis and multifunctional nanomaterial development. Beyond consolidating existing knowledge, this review critically establishes that the superior performance of Murraya koenigii-derived nanoparticles is driven by the synergistic action of its phytochemicals. It further identifies standardized phytochemical profiling as a critical step to overcome reproducibility challenges and proposes a focused research framework to accelerate scalable and translational applications in green nanotechnology.