Eco-synthesized silver nanoparticles from Curcuma longa leaves: Phytochemical and biomedical applications

Abstract

Nanotechnology has revolutionized biomedical sciences, with silver nanoparticles (AgNPs) gaining attention for their antimicrobial, antioxidant, and anti-inflammatory properties. However, conventional synthesis methods often involve toxic chemicals. In this study, an eco-friendly green synthesis approach using Curcuma longa (turmeric) leaf extract to fabricate silver nanoparticles (CL-AgNPs) has been employed, leveraging the plant’s rich phytochemical composition. Although the rhizome of C. longa is well-studied, its leaves remain underexplored for nanoparticle synthesis. Phytochemical screening of the extract revealed the presence of steroids, saponins, phenolic compounds, flavonoids, alkaloids, and glycosides, with tannins absent. The formation of CL-AgNPs was confirmed by a colour change from light brown to dark brown, indicating surface plasmon resonance (SPR), with UV-Vis spectroscopy showing a peak at 413.5 nm. Transmission electron microscopy (TEM) revealed spherical nanoparticles averaging 3.04 ± 0.2 nm, while dynamic light scattering (DLS) indicated a hydrodynamic diameter of 60 nm. Fast Fourier Transform (FFT) analysis showed a d-spacing of 0.24 nm, corresponding to the (111) plane of face-centered cubic silver. Biological assays demonstrated moderate antioxidant activity in DPPH and total reducing power assays with IC50 values of 140.9 and 124.58 µg mL⁻¹ , respectively. Protein denaturation inhibition assays showed a dose-dependent anti-inflammatory effect, reaching 71 % inhibition at 100 µg mL⁻¹ . Nucleic acid leakage and haemolytic assays revealed both therapeutic promise and cytotoxic concerns. These results highlight the biomedical potential of CL-AgNPs while emphasizing the need for further investigations into their safety and biocompatibility.

Keywords

• Curcuma longa
• haemolytic assay
• nanoparticles
• characterization
• anti-inflammatory