The aim of the work is to design green biosynthesized selenium nanoparticles mode to rapidly synthesize selenium nanoparticles (SeNPs) through G. barbadense leaves methanolic extract and confirming SeNPs synthesis by UV–visible spectroscopy. The methodologies applied for this work were field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FE-SEM-EDS) and high-resolution transmission electron microscopy (HR-TEM).

The LC-ESI-Mass analysis of G. barbadense leaves methanolic extract indicates the presence of 11 bioactive compounds, which they are capable of providing electrons for the reduction of selenium ions to SeNPs. This shielding layer can provide steric hindrance surrounding the particles, allowing them to be stabilized.

In addition to assess the anti-cancer efficacy of the SeNPs against the colorectal carcinoma “HCT116" and human pancreas epithelioid carcinoma “PANC1" using the MTT assay. As studies have shown that SeNPs biosynthesis downregulates the cancer cells when compared to normal doxorubicin drug. Markedly, The SeNPs had the most potent cytotoxic activity and HCT116 was more sensitive than PANC1. The IC50 of PANC1 cells were 358.54 ± 3.83 and 349.43 ± 7.76 while, IC50 values of HCT116 cells were 99.41 ± 1.87 and 240.79 ± 6.56 μg/mL for methanolic extract and SeNPs respectively, while the IC50 effect of Doxorubicin on HCT116 is 4.82±0.6 μg/mL and IC50 effect on PANC1 is 2.91±0.2 μg/mL.