Sustainable Synthesis of Ag/TiO₂ Bimetallic Nanoparticles with Enhanced Antidiabetic and Anti-Inflammatory Properties: A Combined Experimental and Computational Analysis

Abstract

Globally, diabetes affects approximately 589 million people and represents a major public health challenge, is a severe health epidemic, especially in low- and middle-income regions where its incidence continues to rising. The main challenge is the increase in diabetic complications and antibiotic resistance linked to conventional treatments. Bi-metallic nanoparticles offer greater multifunctional advantages than single-metal nanoparticles, including enhanced stability and efficacy. Ag/TiO₂ nanoparticles were synthesized using leaf and floral extracts of Couroupita guianensis. Molecular docking identified β-Amyrin palmitate (− 8.1 kcal/mol) and Farnesol (− 6.6 kcal/mol) as potent αamylase inhibitors, with molecular dynamics confirming stable interactions. TEM showed well-dispersed spherical nanoparticles: leaf-mediated (10–250 nm) and flower-mediated (10350 nm), indicating efficient phytochemical-assisted synthesis. XRD confirmed crystalline Ag/TiO₂ with anatase and rutile phases, while FTIR and zeta potential analyses identified phytochemical groups ensuring stability. Antioxidant assays demonstrated appreciable free radical scavenging activity, with flower-mediated nanoparticles exhibiting significantly higher activity than leaf-mediated nanoparticles (p < 0.05). Antibacterial studies showed inhibitory effects against Escherichia coli and Staphylococcus aureus, with flower-mediated Ag/TiO₂ nanoparticles producing larger inhibition zones (p < 0.05). In the α-amylase inhibition assay, flower-mediated nanoparticles achieved 56.87 ± 1.42% inhibition at 100 µg/mL compared with 50.92 ± 1.18% for leaf-mediated nanoparticles (p < 0.05), indicating moderate antidiabetic activity. At 10 µg/mL, leaf-mediated Ag/TiO₂ nanoparticles exhibited 73.61 ± 1.26% anti-inflammatory activity, which was slightly higher than that of flower-mediated nanoparticles (71.61 ± 1.34%). All experiments were performed in triplicate, and the data are presented as mean ± standard deviation. Overall, these findings suggest that Couroupita guianensis-mediated Ag/TiO₂ nanoparticles exhibit moderate in vitro antioxidant, antibacterial, anti-inflammatory, and antidiabetic activities, warranting further optimization and in vivo investigation.