Green synthesis of bimetallic AgZnO Nanoparticles: Synergistic anticancer effects through regulation of gene expression for lung cancer treatment

Lung cancer is the foremost diagnosed cancer in men and the second most common cancer worldwide, highlighting the need for new treatment strategies. In the current study, AgZnO bimetallic nanoparticles (NPs) with average size of 11 nm were successfully synthesized using Salvia officinalis (SO) extract. The as-synthesized AgZnO NPs were characterized by several microscopic and spectroscopic techniques. The distribution of AgZnO nanoparticle curve was ranged from 10 to 20 nm, and the average particle diameter size was approximately 15.6±4.3 nm with zeta potential value of -31.1±5.2 mV. Also, the EDX technique revealed that the weight percentage for Zn, O, and Ag was 5.9 %, 3.6 %, and 90.5 %, respectively. The cytotoxicity of AgZnO NPs was assessed against A549 lung cancer cells and human non-tumorigenic lung epithelial BEAS-2B cells. The as-synthesized AgZnO NPs showed biocompatibility with heathy cells, while they showed high cytotoxicity against A549 lung cancer cells. In addition, AgZnO NPs demonstrated higher cytotoxicity compared to AgNPs synthesized by SO extract, indicating the synergistic effect between Ag and ZnO in the structure of bimetallic nanoparticle. The percentage of apoptosis and necrosis for SO extract was 11.6% (3.69% early apoptosis and 8.07% late apoptosis) and 2.79%, respectively. On the other hand, the apoptosis and necrosis percentage for AgZnO NPs was 29.74% (5.04% early apoptosis and 24.7% late apoptosis) and 9.09%, respectively. The high cytotoxicity effect was found through apoptosis, owing to upregulation of proapoptotic genes (caspase-3, caspase-8, caspase-9, P21, and BAX) and downregulation of antiapoptotic and migration genes (BCL2, cyclin E, cyclin D1, MMP-2, and MMP-9) in A549 cells. In addition, the A549 cells treated with AgZnO NPs illustrated lower migration ability compared to those treated with S. officinalis extract, indicating the role of AgZnO NP in cytotoxicity. Also, arrested cells during sub-G1 phase increased significantly after treatment with AgZnO NPs compared to SO extract (p < 0.05) (17.8% for SO extract and 38% for AgZnO NPs). The results of this study prove the enhanced anticancer effect of AgZnO NPs due to the synergistic effect between Ag and ZnO against the A549 lung cancer cells, which could be further investigated for cancer treatment application.