Green synthesis of silver nanoparticles from mulberry leaf through hot melt extrusion: Enhanced antioxidant, antibacterial, anti-inflammatory, antidiabetic, and anticancer properties

Abstract

In this study, mulberry leaf (ML) extract, along with ML processed by hot melt extrusion (HME) (HML), and ML processed by HME with biopolymer (HMLE), were utilized for the eco-friendly synthesis of silver nanoparticles (AgNPs). The physicochemical properties of AgNPs synthesized from ML, HML, and HMLE extracts were characterized using UV–Vis spectrophotometry, zeta potential analysis, transmission electron microscopy (TEM), dynamic light scattering (DLS), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). HME processing enhanced the active ingredients in the ML extract and increased the reduction efficiency of Ag ions. In the ABTS radical scavenging activity assay, AgNPs synthesized from HMLE (F3) exhibited the highest antioxidant activity with the lowest IC₅₀ value. F3 also demonstrated the lowest minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Escherichia coli and Staphylococcus aureus. In the disk diffusion test, F3 showed the largest zone of inhibition, indicating the highest antimicrobial activity. In the anti-inflammatory assay using albumin inhibition, F3 achieved the highest inhibition rate, followed by the HMLE extract. In contrast, the extract group exhibited no activity in the antidiabetic test, while the AgNPs group showed the highest antidiabetic activity in F3. Additionally, F3 demonstrated the most potent anticancer activity against breast cancer cells, resulting in the lowest cell viability. Overall, this study suggests that AgNPs synthesized using ML extract enhanced via HME processing exhibit superior physiological activities compared to those synthesized using unprocessed ML extract.