QbD-based green synthesis and multifaceted characterization of silver nanoparticles from Mitragyna parvifolia leaves extract with enhanced bio-efficacy

The current study demonstrates a novel, eco-friendly synthesis of silver nanoparticles (AgNPs) using Mitragyna parvifolia leaf extract, guided by a Quality by Design (QbD) approach to enhance their anti-inflammatory efficacy. Distinct from conventional chemical methods, this green strategy leverages phytochemicals as natural reducing and stabilizing agents. A central composite design was employed to optimize reaction temperature and incubation time, enabling controlled nanoparticle synthesis with improved bio-efficacy. The synthesized AgNPs were characterized using spectroscopic and microscopic techniques, confirming the formation of spherical, crystalline nanoparticles with a zeta potential of –27.1 mV, indicative of high stability. UV–Vis spectroscopy revealed a surface plasmon resonance peak at 438 nm, while FTIR analysis indicated the presence of functional groups (–NH, –CH, –C = C), confirming successful capping by M. parvifolia phytoconstituents. XRD analysis confirmed a face-centered cubic structure with an average crystallite size of 13.05 nm, and TEM analysis revealed well-dispersed spherical particles ranging from 18 to 22 nm, with SAED patterns supporting their crystalline nature. The anti-inflammatory potential of the synthesized AgNPs was evaluated in vitro, showing significant COX-2 inhibition (IC₅₀ = 56.49 µg/ml), protein denaturation inhibition (73.89 % at 300 µg/ml), and membrane stabilization (85.94 % at 100 µg/ml), substantially outperforming the crude extract. These enhancements are attributed to the nanoscale size and effective phytochemical interaction. This study underscores the promise of QbD-optimized, plant-mediated AgNPs as potential anti-inflammatory agents and highlights their relevance in the development of sustainable nanomedicine.