Gold nanoparticles from Artemisia absinthium, Morus nigra, and Peganum harmala: biosynthesis, characterization, and their biological evaluations against cancer cells.

Background and purpose: Metallic nanoparticles (NPs) can be applied in various biomedical fields, such as antibacterial and anti-cancer agents. Synthesizing metallic NPs by green chemistry procedures makes them eco-friendly and easier to prepare. This study aimed to develop 3 different gold (Au) NPs, using plant extracts including Artemisia absinthium (AA) aerial parts, Morus nigra (MN) fruits, and Peganum harmala (PH) seeds.

Experimental approach: Green AuNPs were synthesized by mixing plant extracts and HAuCl₄3H₂O and heating the mixture at 60 °C. Cytotoxic activity of synthesized AuNPs was evaluated using the MTT assay, followed by flow cytometry to assess its mechanism. Synthesis of plant AuNPs was confirmed by relevant color change, DLS, Zeta potential, and were characterized by a relevant surface plasmon resonance peak for AuNPs between 500 to 600 nm.

Findings/results: AA-AuNPs, MN-AuNPs, and PH-AuNPs were cytotoxic against cancer cell lines in a dose-dependent manner. Results also revealed that PH-AuNPs were the most potent NPs (IC₅₀ values of 7.7, 16.7, 30, and 40 μg/mL against HeLa, HT-29, OVCAR3 and MCF-7 cell lines, respectively). HeLa cells were the most sensitive cell line toward all tested NPs, significantly. Flow cytometry results confirmed that the cytotoxic effects of AuNPs were mediated through apoptosis induction.

Conclusion and implications: Using plants to formulate metallic NPs is inexpensive, easily accessible, and renewable. Additionally, due to their considerable cytotoxicity, their applications as a cancer treatment option is a promising approach that warrants further investigation. Thus, the rapidly synthesized AuNPs can play a role in nanotechnology and biomedical applications.