Bioactivities of the Green Synthesized Silver Nanoparticles Reduced Using Allium cepa L Aqueous Extracts Induced Apoptosis in Colorectal Cancer Cell Lines

Abstract

Allium cepa L (A. cepa) extract is frequently used as an adjuvant food in cancer treatment. We hypothesized that it contains a source of anticancer activity. There is a need to synthesize the silver nanoparticles (AgNPs) using an environment-friendly green synthesis reduction method using an aqueous extract of A. cepa. The AgNPs-CEPA were prepared by reduction method using the aqueous extract of A. cepa. The formed AgNPs-CEPA were characterized for their sizes and charge distribution. The AgNP-CEPA was investigated for its antioxidant and anticancer properties. Cell viability was evaluated by MTT assay. Gene expression was evaluated by real-time polymerase chain reaction (RT-PCR), and apoptosis measurement was carried out by flow cytometry in AgNP-CEPA-treated cells. The results showed a uniform size for AgNPs-CEPA of $155\pm 2.1$  nm with a zeta potential of $-37.3\pm \left(-2.92\right)$ mv. The produced AgNPs-CEPA are biocompatible with anticancer action and a moderate level of antioxidant reactivity. AgNPs-CEPA showed better reducing activity for A. cepa extract compared to the AgNPs-CEPA. AgNP-CEPA treatment of human colorectal cancer cell lines (HT-29 and SW620) inhibited cell proliferation and altered Bcl2 family gene expression. Moreover, exposure of cell lines to AgNPs-CEPA resulted in the significant induction of apoptosis compared to A. cepa and AgNO3. These findings indicate that AgNP-CEPA induces apoptosis by inhibiting Bcl2 family gene expression, suggesting that this formula is a promising anticancer agent for treating colorectal cancer.