Callus-derived silver nanoparticles from myrmecodia tuberosa: green synthesis and antioxidant properties

Abstract

Green synthesis of Silver nanoparticles (AgNPs) using plant-based materials is an environmentally friendly path for the synthesis of silver nanoparticles instead of traditional chemical methods. This study presents the first biosynthesis of AgNPs using an ethanolic extract obtained from in vitro callus cultures of Myrmecodia tuberosa Jack, an endangered medicinal epiphyte and conservation‑friendly biotechnological platform. Cotyledon explants were successfully induced high-frequency friable, green callus and the ethanolic extract acted as reducing and stabilizing agent. UV‑Vis spectroscopy revealed surface plasmon resonance peaks at 420–450 nm with a visible color change from light brown to dark brown, confirming the AgNP formation. The most intense and well-defined SPR peak indicating optimal nanoparticle synthesis was observed after 6–8 days static incubation at 35°C using 2 mM AgNO₃. In the DPPH radical scavenging assay, it could moderate antioxidant activities, with IC₅₀ = 51.80±0.035 μg mL⁻¹) which was more than that of parent callus extract (IC₅₀ = 58.91±0.097μgmL⁻¹). This improvement is probably a result of synergistic effects between silver core and phytochemical capping layer. These results indicate that callus cultures of M. tuberosa is an environmentally friendly, sustainable and conservation-friendly source of reducing metabolites for the preparation of green nanomaterials applicable in biomedical practices.