Development of Coumaric Acid/Pullulan Prodrug Nanoparticles for Antioxidant and α-Amylase and α-Glucosidase Inhibition Applications

Over the last few decades, prodrug nanoparticles have exhibited several appealing attributes and have eventually received impressive attention in the scientific communities. The current research study aimed to develop innovative coumaric acid (CA) grafted pullulan (Pull) based conjugates (CA-g-Pull) and their nanoparticles and evaluate their antioxidant and α-amylase/α-glucosidase inhibition potentials. In this context, variable amounts of CA were grafted with Pull via Steglich esterification reaction protocol and the resulting conjugates were structurally characterized with ¹H NMR, FTIR, DSC, TGA, XRD and SEM analyses. These conjugates spontaneously self-aggregated in an aqueous environment to yield nanoparticles (F-1– F-3), which illustrated acceptable particle sizes (276–296 nm), PDI values (0.313–0.460) and zeta potentials (-10 to -20 mV). The prodrug nanoparticles revealed their spherical structures under TEM analyses. Among various nanoparticles, formulation F-3 with the highest CA contents (DS, 0.26) conferred an improved DPPH and ABTS-free radical scavenging and α-amylase and α-glucosidase inhibition potentials, which were enhanced with increasing incubation time. These nanoparticles also depicted excellent cytocompatibility as evaluated through hemolysis assay, CCK-8 assay and live/dead cell staining protocols. Thus, the newly developed prodrug nanoparticles could be employed as promising biomaterials with acceptable antioxidant and α-amylase and α-glucosidase inhibition activities.