Anti-diabetic Potential of Silver Nanoparticles Synthesized with Argyreia nervosa Leaf Extract High Synergistic Antibacterial Activity with Standard Antibiotics Against Foodborne Bacteria

The current investigation highlighted a novel cost-effective green synthesis of silver nanoparticles (AgNPs) using Argyreia nervosa leaves extract (ANE) as a potential reducing and capping agent. Surface plasmon resonance confirmed the formation of AgNPs with maximum absorbance at λ_max = 435 nm. FTIR revealed the involvement of biological macromolecules of ANE in the synthesis and stabilization of AgNPs. HRTEM images showed that the size of the spherical AgNPs ranged between 5 and 40 nm with average particle size of about 15 nm. The ANE-AgNPs showed inhibition activity against carbohydrate digestive enzymes α-amylase and α-glucosidase, with EC₅₀ of 55.5 and 51.7 µg/mL, respectively, indicating its antidiabetic potential. The in vitro antioxidant activity of ANE-AgNPs was evaluated in terms of ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and DPPH (1,1-diphenyl-2-picrylhydrazyl) free radicals scavenging assays with IC₅₀ value of 44.3 and 55.9 µg/mL, respectively. The AgNPs displayed strong antibacterial activity against foodborne bacteria with zone of inhibition 16.0 and 12.5 mm for Escherichia coli and Staphylococcus aureus, respectively, and also exhibited strong synergistic antibacterial activity together with standard antibiotics. The biological activity in terms of antioxidant, antidiabetic and antibacterial potential could be useful in various bio-applications such as cosmetics, food, and biomedical industry.