Biogenic Silver Nanoparticles from Antidiabetic Plants: Dual Evaluation of Insulin-Mimetic and Antibacterial Activities

Abstract

Type 2 diabetes mellitus and associated secondary complications, such as impaired wound healing and multidrug-resistant bacterial infections, pose severe global health challenges. While conventional oral hypoglycemic therapies manage hyperglycemia, their clinical utility is frequently compromised by poor bioavailability, non-targeted distribution, and systemic side effects. Nanomedicine offers a transformative alternative; however, traditional chemical and physical nanoparticle synthesis methods introduce toxic residues and high environmental costs. This review comprehensively examines the green synthesis, biophysical characterization, and multifaceted therapeutic evaluation of biogenic silver nanoparticles (AgNPs) functionalized with extracts from antidiabetic medicinal plants. Phyto-synthesis represents a rapid, sustainable, and economically viable "one-pot" approach in which plant secondary metabolites including polyphenols, flavonoids, and terpenoids simultaneously act as reducing, capping, and stabilizing agents. These natural biomolecules form an organic bio-corona that provides long-term colloidal stability and suppresses particle agglomeration. Analytically, successful AgNP formation is validated by visible color transitions driven by localized surface plasmon resonance (LSPR), with face-centered cubic crystalline phases confirmed through X-ray diffraction. Biologically, these biogenic nanoformulations demonstrate potent dual-action efficacy. They mitigate metabolic dysregulation via the robust in vitro inhibition of carbohydrate-digesting enzymes (α‑amylase and α‑glucosidase) and the activation of downstream insulin-mimetic signaling cascades. Concurrently, they exhibit broad-spectrum bactericidal and anti-biofilm activities by inducing membrane rupture, deactivating respiratory enzymes, and generating reactive oxygen species. Consequently, plant-mediated biogenic AgNPs bridge the gap between traditional herbal medicine and nanotechnology, offering a highly synergistic, biocompatible, and multi-targeted therapeutic platform capable of simultaneously managing metabolic dysregulation and secondary microbial infections.