Hypnea musciformis-mediated Ag/AgCl-NPs inhibit pathogenic bacteria, HCT-116 and MCF-7 cells' growth in vitro and Ehrlich ascites carcinoma cells in vivo in mice.

Abstract

In the present study, Ag/AgCl-NPs were biosynthesised using Hypnea musciformis seaweed extract; NPs synthesis was confirmed by a change of colour and observation of a razor-sharp peak at 424 nm by UV-visible spectroscopy. Synthesised nanoparticles were characterised by transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray powder diffraction and Fourier transform infrared spectroscopy. Bacterial cell growth inhibition proves that the Ag/AgCl-NPs have strong antibacterial activity and cell morphological alteration was observed in treated bacterial cells using propidium iodide (PI). Ag/AgCl-NPs inhibited Ehrlich ascites carcinoma (EAC) cells, colorectal cancer (HCT-116) and breast cancer (MCF-7) cell line in vitro with the IC₅₀ values of 40.45, 24.08 and 36.95 μg/ml, respectively. Initiation of apoptosis in HCT-116 and MCF-7 cells was confirmed using PI, FITC-annexin V and Hoechst 33342 dye. No reaction oxygen species generation was observed in both treated and untreated cell lines. A significant increase of ATG-5 gene expression indicates the possibility of autophagy cell death besides apoptosis in MCF-7 cells. The initiation of apoptosis in EAC cells was confirmed by observing caspase-3 protein expression. Ag/AgCl-NPs inhibited 22.83% and 51% of the EAC cell growth in vivo in mice when administered 1.5 and 3.0 mg/kg/day (i.p.), respectively, for 5 consequent days.