Green synthesis of gold nanoparticles from Coleus scutellarioides (L.) Benth leaves and assessment of anticancer and antioxidant properties

Abstract

Gold nanoparticles (AuNPs) have gained significant attention in the field of biomedicine due to their versatile potential and diverse applications. In this study, AuNPs were biologically synthesized using the leaf extract of Coleus scutellarioides (L.) Benth to explore the in vitro anticancer and antioxidant properties. The synthesized AuNPs underwent thorough characterization through various analyses, the UV–Visible Spectroscopy (UV–Vis) of the AuNPs displayed a peak at 532 nm, indicating the occurrence of surface plasmon resonance. The crystalline structure of the AuNPs was confirmed by analyzing the X-ray Diffraction pattern (XRD). Moreover, Transmission Electron Microscopy (TEM) analysis revealed a spherical morphology for the AuNPs, with an average particle size of 40.10 nm, consistent with the measurements obtained from Dynamic light scattering (DLS). After that, the biological performance of those biomolecules functionalized AuNPs was studied. This study investigated the potential cytotoxic effects of synthesized AuNPs using the MTT assay. The assay was employed to evaluate the cell viability against the human breast cancer cell line (MDA-MB-231) compared to the human foreskin fibroblast cell line (Hs-27), with concentrations ranging from 7.5 to 60 µg/ml over 24 h. The study findings reveal a concentration-dependent impact of synthesized AuNPs on MDA-MB-231 cells. As the AuNPs concentration increases, there is a corresponding increase in the inhibition of MDA-MB-231 cells, reaching an IC50 value of 36.10 µg/ml within a 24-hour period. Contrarily, the synthesized AuNPs exhibited no apparent toxicity against the noncancerous normal Hs-27 cells. Furthermore, the antioxidant efficacy of AuNPs was evaluated through a free radical scavenging DPPH assay. These findings suggest the potential of Coleus scutellarioides (L.) Benth leaf extract as an effective bio-reductant for synthesizing stable AuNPs with anticancer activity and antioxidant properties.