Microwave-assisted ultrafine silver nanoparticle synthesis using Mitragyna speciosa for antimalarial applications

Abstract

Abstract This study investigates the antiplasmodial activity of ultrafine silver nanoparticles (AgNPs, 2–5 nm) synthesized using a green approach involving the Mitragyna speciosa extract and emphasizing the microwave-assisted irradiation technique. Various synthesis parameters were optimized, resulting in the successful production of spherical AgNPs, which exhibited a characteristic surface plasmon resonance peak at around 440 nm. The synthesized AgNPs demonstrated high stability, indicated by a zeta potential value of −28 mV. The antimalarial efficacy of the microwave-assisted AgNPs against the P. falciparum strain was evaluated, demonstrating a half-maximum inhibitory concentration (IC50) value of 1.56 µg·mL−1. Further enhancement in the antimalarial performance was observed when the AgNPs were conjugated with chloroquine (CQ), a traditional antimalarial drug, achieving an impressive IC50 value of 24 ng·mL−1. Additionally, all formulations exhibited low toxicity, with a cytotoxic concentration (CC50) exceeding 800 µg·mL−1 in Vero cells. Complementing these experimental findings, specific computational studies offered insights into the interactions between silver atoms and bioactive compounds in M. speciosa, as well as shedding light on the dynamics of CQ functionalization. These experimental and computational findings emphasize the potential of a sustainable, low-toxicity, and cost-effective AgNP synthesis process, showcasing significant promise in advancing green nanotechnology for the development of effective antimalarial medications.